Power converter, power control device, and power control method

Abstract

To vary output and / or input of a charge / discharge facility according to transitional frequency fluctuation and voltage phase fluctuation of a system to suppress the frequency fluctuation of the system.SOLUTION: A power control device of an embodiment controls a power converter connected with an AC electric circuit and is equipped with: electric quantity measurement means of measuring electric quantity of the electric circuit; phase calculation means of calculating a phase of the electric quantity measured by the electric quantity measurement means; phase adjustment means of adjusting the phase of the electric quantity calculated by the phase calculation means; and command value calculation means of calculating a control command value to the power converter on the basis of the phase adjusted by the phase adjustment means.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] Embodiments of the present invention relate to a power conversion device, a power control device, and a power control method.

Background Art

[0002] Currently, frequency regulation of the power system is mainly performed by controlling the output of thermal power plants and hydroelectric power plants.

[0003] Transient frequency fluctuations before the output control of thermal power plants and hydroelectric power plants takes effect are suppressed by the inertial response of rotating machines such as synchronous generators. Charge-discharge facilities using renewable energy such as solar power generation and wind power generation have variable outputs due to changes in the natural environment. In order to suppress frequency fluctuations, frequency regulation by charge-discharge control of battery systems is being put into practical use.

[0004] A power conversion device (including a control device) applied to a battery system for frequency regulation measures the frequency of an electric circuit, obtains input / output command values according to the frequency, and controls the input / output of the power conversion device according to the command values. In addition, the power conversion device measures the voltage phase of the electric circuit, obtains a control phase, and controls the input / output according to the command values. When the voltage phase changes due to a change in the frequency of the electric circuit or the like, the control phase follows the voltage phase of the electric circuit, and the control device controls the input / output according to the followed control phase. Therefore, the power conversion device can stably control the input / output according to the command values even when the voltage phase of the electric circuit changes.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] Power generation equipment using synchronous generators, such as thermal and hydroelectric power plants, and charging / discharging equipment such as batteries, control the output of the prime mover through a governor-free function when the frequency of the power grid changes, thereby suppressing frequency fluctuations. For transient frequency fluctuations and voltage phase fluctuations before the prime mover output changes, the output of the synchronous generator changes due to the inertia of the synchronous generator, suppressing transient frequency fluctuations. In other words, power generation equipment using synchronous generators and charging / discharging equipment such as batteries have a function to suppress frequency fluctuations through inertial response.

[0007] On the other hand, wind power and solar power generation cause fluctuations in output due to variations in wind speed and solar radiation, which in turn causes fluctuations in the output command value and thus the output itself, leading to frequency fluctuations in the power grid. Furthermore, power converters used in wind power, solar power, fuel cell systems, and battery storage systems are static devices and do not possess the inertia that synchronous generators have. In addition, because these power converters control the output and / or input according to the command value, they cannot suppress transient frequency fluctuations.

[0008] As the number of charging and discharging facilities connected to the power grid via power conversion devices such as wind and solar power generation increases, and the proportion of power generation facilities using synchronous generators such as thermal and hydroelectric power plants, and charging and discharging facilities such as batteries (charging and discharging facilities with inertia) decreases, there are concerns that the inertia of the entire power grid will decrease, leading to larger frequency fluctuations in the power grid. Therefore, there is a need for power conversion devices that can suppress transient frequency fluctuations to the same extent as power generation facilities using synchronous generators and charging and discharging facilities such as batteries.

[0009] One proposed method for realizing such a power conversion device is virtual synchronous generator control. This control system incorporates a calculation unit in the power conversion device's control device that simulates the characteristics of a synchronous generator, and controls the output of the power conversion device based on the calculation results to simulate the output of a synchronous generator.

[0010] Virtual synchronous generator control requires complex calculations, which presents the challenge of calculation time delays. Furthermore, since the output of power converters behaves differently depending on the functions and constants used in the calculations, if multiple power converters are connected to the same system, the control of each power converter may interfere with each other, potentially adversely affecting the power system.

[0011] The problem that the present invention aims to solve is to provide a power converter, a power control device, and a power control method that enable the output and / or input of a charging and discharging device to be changed in response to transient frequency fluctuations and voltage phase fluctuations of the grid, thereby suppressing frequency fluctuations of the grid. [Means for solving the problem]

[0012] The power control device of the embodiment is a power control device that controls a power converter connected to an AC electrical circuit, and comprises: an electrical quantity measuring means for measuring the electrical quantity of the electrical circuit; a phase calculation means for determining the phase of the electrical quantity measured by the electrical quantity measuring means; a phase adjustment means for adjusting the phase of the electrical quantity determined by the phase calculation means; and a command value calculation means for determining a control command value for the power converter based on the phase adjusted by the phase adjustment means. Furthermore, the phase adjustment means uses a first-order lag calculation or a calculation that causes a phase lag other than the first-order lag calculation for phase adjustment in the phase adjustment means, so that when the input signal of the phase adjustment means continues to change, the amount of change in the output signal of the phase adjustment means is smaller than the amount of change in the input signal. . [Effects of the Invention]

[0013] According to the present invention, it becomes possible to change the output and / or input of the charging and discharging equipment in response to transient frequency fluctuations and voltage phase fluctuations of the grid, thereby suppressing frequency fluctuations of the grid. [Brief explanation of the drawing]

[0014] [Figure 1] A conceptual diagram showing an example of the configuration of a charging and discharging facility having a power conversion device according to the first embodiment (situation when the grid frequency is stable). [Figure 2] A conceptual diagram showing an example of the configuration of a charging and discharging facility having a power conversion device according to the first embodiment (situation when the grid frequency decreases). [Figure 3]Conceptual diagram showing an example of the configuration of a charging and discharging facility having a power conversion device according to the first embodiment (situation when the system frequency increases). [Figure 4] Conceptual diagram showing a simplified example of the configuration of a charging and discharging facility having a power conversion device according to the prior art (situation when the system frequency is stable). [Figure 5] Conceptual diagram showing a simplified example of the configuration of a charging and discharging facility having a power conversion device according to the prior art (situation when the system frequency decreases). [Figure 6] Conceptual diagram showing a simplified example of the configuration of a charging and discharging facility having a power conversion device according to the prior art (situation when the system frequency increases). [Figure 7A] Flowchart showing an example of the operation of a power control device according to the first embodiment. [Figure 7B] Diagram for explaining the difference in effects between this embodiment and the prior art. [Figure 8] Conceptual diagram showing an example of the configuration of a charging and discharging facility having a power conversion device according to the second embodiment (situation when the system frequency is stable). [Figure 9] Conceptual diagram showing an example of the configuration of a charging and discharging facility having a power conversion device according to the second embodiment (situation when the system frequency decreases). [Figure 10] Conceptual diagram showing an example of the configuration of a charging and discharging facility having a power conversion device according to the second embodiment (situation when the system frequency increases). [Figure 11] Flowchart showing an example of the operation of a power control device according to the second embodiment. [Figure 12] Conceptual diagram showing an example of the configuration of a charging and discharging facility having a power conversion device according to the third embodiment. [Figure 13] Flowchart showing an example of the operation of a power control device according to the third embodiment. [Figure 14] Conceptual diagram showing an example of the configuration of a charging and discharging facility having a power conversion device according to the fourth embodiment. [Figure 15] Flowchart showing an example of the operation of a power control device according to the fourth embodiment. [Figure 16]A conceptual diagram showing an example of the configuration of a charging and discharging equipment having a power conversion device according to the fifth embodiment. [Figure 17] A flowchart showing an example of the operation of a power control device according to the fifth embodiment. [Figure 18A] A diagram showing an example of the configuration of a charging and discharging equipment having a power conversion device according to the embodiment of 6-1. [Figure 18B] A diagram showing an example of the configuration of a charging and discharging equipment having a power conversion device according to the embodiment of 6-2. [Figure 18C] A diagram showing an example of the configuration of a charging and discharging equipment having a power conversion device according to the embodiment of 6-3. [Figure 18D] A diagram showing an example of the configuration of a charging and discharging equipment having a power conversion device according to the embodiment of 6-4. [Figure 18E] A diagram showing an example of the configuration of a charging and discharging equipment having a power conversion device according to the embodiment of 6-4. [Figure 18F] A diagram showing an example of the functional configuration of a phase adjustment unit provided in a power control device according to the embodiments of 6-1, 6-2, 6-3, 6-4, and 6-5. [Figure 19A] A flowchart showing an example of the operation of the power control device according to the embodiment 6-1. [Figure 19B] A flowchart showing an example of the operation of the power control device according to the 6-2 embodiment. [Figure 19C] A flowchart showing an example of the operation of a power control device according to the 6-3 embodiment. [Figure 19D] A flowchart showing an example of the operation of a power control device according to the 6-4 embodiment. [Figure 19E] A flowchart showing an example of the operation of the power control device according to the 6-5 embodiment. [Figure 20A] A diagram showing an example of the configuration of a charging and discharging equipment having a power conversion device according to the embodiment of 7-1. [Figure 20B] A diagram showing an example of the configuration of a charging and discharging equipment having a power conversion device according to the embodiment of 7-2. [Figure 20C] A diagram showing an example of the configuration of a charging and discharging equipment having a power conversion device according to the embodiment of 7-3. [Figure 20D] A diagram showing an example of the configuration of a charging and discharging equipment having a power conversion device according to the embodiment of 7-4. [Figure 20E] A diagram showing an example of the configuration of a charging and discharging equipment having a power conversion device according to the embodiment of 7-5. [Figure 20F] A diagram showing an example of the functional configuration of a phase adjustment unit provided in a power control device according to the embodiments of 7-1, 7-2, 7-3, 7-4, and 7-5. [Figure 21A] A flowchart showing an example of the operation of the power control device according to the embodiment of 7-1. [Figure 21B] A flowchart showing an example of the operation of a power control device according to the 7-2 embodiment. [Figure 21C] A flowchart showing an example of the operation of a power control device according to the 7-3 embodiment. [Figure 21D] A flowchart showing an example of the operation of a power control device according to the 7-4 embodiment. [Figure 21E] A flowchart showing an example of the operation of a power control device according to the 7-5 embodiment. [Figure 22A] A diagram showing an example of the configuration of a charging and discharging equipment having a power conversion device according to the eighth embodiment. [Figure 22B] A diagram showing an example of the functional configuration of each phase adjustment unit provided in the power control device according to the eighth embodiment. [Figure 23A] A flowchart showing an example (part 1) of the operation of a power control device according to the eighth embodiment. [Figure 23B] A flowchart showing an example (part 2) of the operation of the power control device according to the eighth embodiment. [Figure 23C] A flowchart showing an example (part 3) of the operation of a power control device according to the eighth embodiment. [Figure 23D] A flowchart showing an example (part 4) of the operation of a power control device according to the eighth embodiment. [Figure 23E] A flowchart showing an example (part 5) of the operation of the power control device according to the eighth embodiment. [Figure 24A]A diagram showing an example of the configuration of a charging and discharging equipment having a power conversion device according to the embodiment of 9-1. [Figure 24B] A diagram showing an example of the configuration of a charging and discharging equipment having a power conversion device according to the embodiment of 9-2. [Figure 24C] A diagram showing an example of the configuration of a charging and discharging equipment having a power conversion device according to the embodiment of 9-3. [Figure 25A] A flowchart showing an example of the operation of a power converter according to the embodiment 9-1. [Figure 25B] A flowchart showing an example of the operation of a power converter according to the 9-2 embodiment. [Figure 25C] A flowchart showing an example of the operation of a power converter according to the 9-3 embodiment. [Figure 26A] A diagram showing an example of the configuration of a charging and discharging equipment having a power conversion device according to the embodiment of 10-1. [Figure 26B] A diagram showing an example of the configuration of a charging and discharging equipment having a power conversion device according to the embodiment of 10-2. [Figure 26C] A diagram showing an example of the configuration of a charging and discharging equipment having a power conversion device according to the embodiment of 10-3. [Figure 26D] A diagram showing an example of the functional configuration of the comparison / determination unit 102 provided in the power conversion device according to the embodiments of 10-1, 10-2, and 10-3. [Figure 27A] A flowchart showing an example of the operation of a power converter according to the 10-1 embodiment. [Figure 27B] A flowchart showing an example of the operation of a power converter according to the 10-2 embodiment. [Figure 27C] A flowchart showing an example of the operation of a power converter according to the 10-3 embodiment. [Figure 28] A conceptual diagram showing an example of the configuration of a charging and discharging equipment having a power conversion device according to the 11th embodiment. [Figure 29] A flowchart showing an example of the operation of a power control device according to the 11th embodiment. [Figure 30]A conceptual diagram showing an example of the configuration of a charging and discharging equipment having a power conversion device according to the 12th embodiment. [Figure 31] A flowchart illustrating an example of the operation of a power control device according to the 12th embodiment. [Figure 32] A conceptual diagram showing an example of the configuration of a charging and discharging equipment having a power conversion device according to the 13th embodiment. [Figure 33] A diagram illustrating a specific example (part 1) of calculations in the main part of the power control device 2 described in the first embodiment. [Figure 34] A diagram illustrating a specific example (part 2) of calculations in the main part of the power control device 2 described in the first embodiment. [Figure 35A] A diagram illustrating specific example 1-1 of calculations applicable to the phase adjustment unit 11 in Figure 33 or the phase adjustment unit 11 in Figure 34. [Figure 35B] A diagram illustrating specific examples 1-2 of calculations applicable to the phase adjustment unit 11 in Figure 33 or the phase adjustment unit 11 in Figure 34. [Figure 36A] A diagram illustrating a specific example 2-1 of a calculation applicable to the phase adjustment unit 11 in Figure 33 or the phase adjustment unit 11 in Figure 34. [Figure 36B] A diagram illustrating specific example 2-2 of a calculation applicable to the phase adjustment unit 11 in Figure 33 or the phase adjustment unit 11 in Figure 34. [Figure 37A] A diagram illustrating specific example 2-3 of calculations applicable to the phase adjustment unit 11 in Figure 33 or the phase adjustment unit 11 in Figure 34. [Figure 37B] A diagram illustrating specific example 2-4 of a calculation applicable to the phase adjustment unit 11 in Figure 33 or the phase adjustment unit 11 in Figure 34. [Figure 38A] A diagram illustrating specific example 2-5 of a calculation applicable to the phase adjustment unit 11 in Figure 33 or the phase adjustment unit 11 in Figure 34. [Figure 38B] A diagram illustrating specific example 2-6 of calculations applicable to the phase adjustment unit 11 in Figure 33 or the phase adjustment unit 11 in Figure 34. [Figure 39A] This figure illustrates specific example 3-1 of calculations applicable to the phase adjustment unit 11 in Figure 33. [Figure 39B] This figure illustrates specific example 3-2 of the calculations applicable to the phase adjustment unit 11 in Figure 34. [Figure 40A] This figure illustrates a specific example 4-1 of calculations applicable to the phase adjustment unit 11 in Figure 33. [Figure 40B] This figure illustrates a specific example 4-2 of the calculations applicable to the phase adjustment unit 11 in Figure 34. [Figure 41A] This figure illustrates specific example 4-3 of calculations applicable to the phase adjustment unit 11 in Figure 33. [Figure 41B] This figure illustrates a specific example 4-4 of the calculations applicable to the phase adjustment unit 11 in Figure 34. [Figure 42] Figure 33 illustrates a specific example of calculation 5 applicable to the phase adjustment unit 11. [Figure 43A] This figure illustrates a specific example 6-1 of calculations applicable to the phase adjustment unit 11 in Figure 33. [Figure 43B] This figure illustrates a specific example 6-2 of the calculations applicable to the phase adjustment unit 11 in Figure 33. [Figure 44A] This figure illustrates a specific example 7-1 of calculations applicable to the phase adjustment unit 11 in Figure 33. [Figure 44B] This figure illustrates a specific example 7-2 of the calculations applicable to the phase adjustment unit 11 in Figure 34. [Figure 45A] Figures 28, 30, and 32 illustrate a specific example of the inertia simulation control signal generation unit 15, illustrating the case where the inertia simulation control signal is generated from the difference between the output of the phase adjustment unit 13 and the output of the voltage phase calculation unit 12. [Figure 45B] Figures 28, 30, and 32 illustrate a specific example of the inertia simulation control signal generation unit 15, illustrating the case where the inertia simulation control signal is generated from the phase difference generated during the calculation process of the phase adjustment unit 13. [Modes for carrying out the invention]

[0015] The embodiments will be described below with reference to the drawings.

[0016] [First Embodiment] First, the first embodiment will be described.

[0017] Figures 1 to 3 are conceptual diagrams showing examples of the configuration of a charging and discharging equipment having a power converter according to the first embodiment. Figure 1 shows the situation when the grid frequency is stable in the first embodiment, Figure 2 shows the situation when the grid frequency decreases in the same embodiment, and Figure 3 shows the situation when the grid frequency increases in the same embodiment. In Figures 1 to 3, vectors A0, A1, A2, A3, and A10, which indicate the phase angles of the signals in each part, are schematically shown on a rotating coordinate system. The phase angle when the vector on the rotating coordinate system is pointing to the right is 0°. When the vector rotates clockwise, the phase angle becomes a negative value, and when the vector rotates counterclockwise, the phase angle becomes a positive value.

[0018] The charging and discharging equipment shown in Figures 1 to 3 is, for example, a charging and discharging system for a battery storage system.

[0019] In this embodiment, an example of a charging and discharging system for a "battery storage system" is shown, but it is also possible to use other types of charging and discharging equipment (e.g., charging and discharging equipment for wind power generation, solar power generation, fuel cell systems, etc.), or even substitute the charging and discharging equipment with load equipment. The fact that it is not limited to charging and discharging equipment is also true in other embodiments described later. In addition, in this embodiment, an example is shown where the charging and discharging equipment is connected to a "power grid," but it may be connected to another AC electrical circuit (e.g., a distribution system, a power supply circuit, etc.) instead of a power grid. In addition, in this embodiment, an example is shown where the phase of "voltage" is adjusted, but it may be configured to adjust the phase of other electrical quantities (e.g., power, current, etc.) rather than just voltage. Furthermore, the measured value used for phase adjustment is not limited to the voltage value of the power grid, but may be other electrical quantities (e.g., power, current, etc.). The value used in the adjustment calculation may be the value of the phase trigonometric function (e.g., cosθ, sinθ) or the amount of phase change (Δθ).

[0020] The charging and discharging equipment shown in Figures 1 to 3 comprises, as basic components, a main transformer M, a parallel circuit breaker CB, a power converter 1 and a power control device 2 which constitute a static power conversion device 3.

[0021] The power converter 1 is connected to the power system S via a parallel circuit breaker CB and a main transformer M. Of the electrical circuits connecting the power converter 1 and the power system S, an instrument transformer VT is installed in the circuit connecting the power system S and the main transformer M, and a current transformer CT1 is installed in the circuit connecting the output side of the power converter 1 and the parallel circuit breaker CB. The instrument transformer VT outputs a voltage signal corresponding to the voltage of the power system S (system voltage). The current transformer CT1 outputs a current signal corresponding to the input and output current of the power converter 1.

[0022] The power converter 1 is connected to the storage battery B. The power converter 1 performs power input / output to the power system S and charging / discharging of the storage battery B according to signals provided from the power control device 2 via the U-phase signal generation unit 5A, V-phase signal generation unit 5B, and W-phase signal generation unit 5C, which will be described later. For example, if the phase difference (difference in phase angle) between the system voltage and the output voltage of the power converter 1 is θ, then the output (discharge) of the active power of the power converter 1 will be proportional to sinθ. Therefore, the larger θ is, the larger the output of the power converter 1 will be.

[0023] The power control device 2 receives various signals, which will be described later, to generate command values ​​for the power converter 1, and outputs signals corresponding to these command values ​​to the power converter 1. When the power converter 1 is outputting (discharging), the power control device 2 ensures that the phase of the output voltage of the power converter 1 is ahead of the phase of the grid voltage. Conversely, when the power converter 1 is inputting (charging), the power control device 2 ensures that the phase of the output voltage of the power converter 1 is behind the phase of the grid voltage.

[0024] This charging and discharging equipment is equipped with an active power and reactive power calculation unit 201, an active power control command value calculation unit 202, and a reactive power / voltage control command value calculation unit 203.

[0025] The active power and reactive power calculation unit 201 receives a voltage signal transmitted from an instrument transformer VT that outputs a voltage signal corresponding to the voltage of the power system S (system voltage), and a current signal transmitted from a current transformer CT that outputs a current signal corresponding to the output current of the power converter 1, and calculates and outputs the active power measurement value and the reactive power / voltage measurement value.

[0026] The active power control command value calculation unit 202 receives the automatic frequency control command value (AFC command value) and governor-free signal transmitted from the higher-level control system, generates an active power control command value from these, and outputs it.

[0027] The reactive power / voltage control command value calculation unit 203 receives voltage commands and reactive power commands transmitted from a higher-level control system, calculates reactive power / voltage control command values ​​from them, and outputs them.

[0028] The individual signals output from the active power and reactive power calculation unit 201, the active power control command value calculation unit 202, and the reactive power / voltage control command value calculation unit 203 are transmitted to the power control device 2.

[0029] The power control device 2 includes a grid voltage measuring unit (electric quantity measuring means) 2a, a phase calculation unit (phase calculation means) 2b, a voltage command value calculation unit (command value calculation means) 2c, a two-phase to three-phase conversion unit (two-phase to three-phase conversion means) 2d, and a calculation unit 2e, as well as a phase adjustment unit (phase adjustment means) 11 specific to this embodiment. Furthermore, the power control device 2 includes a calculation unit 3a, a d-axis current command value calculation unit 3b, a calculation unit 3c, a calculation unit 3d, a q-axis current command value calculation unit 3e, and a calculation unit 3f to generate a signal to be supplied to the voltage command value calculation unit 2c, as well as a power converter current measuring unit 2f and a power converter current dq conversion unit 2g.

[0030] The power converter current measurement unit 2f receives the current signal output from the current transformer CT1, measures the AC waveform of the current in the power converter 1, and outputs the measured value (converter current measurement value).

[0031] The power converter current dq conversion unit 2g receives the converter current measurement value output from the power converter current measurement unit 2f, performs a dq conversion, and obtains and outputs the measured values ​​of the d-axis current and q-axis current (d-axis current measurement value and q-axis current measurement value).

[0032] The calculation unit 3a receives the active power control command value output from the active power control command value calculation unit 202, as well as the active power measurement value output from the active power and reactive power calculation unit 201, and outputs the difference between the two (active power deviation).

[0033] The d-axis current command value calculation unit 3b receives the difference output from the calculation unit 3a, calculates the d-axis current command value from the difference signal, and outputs it.

[0034] The calculation unit 3c receives the d-axis current command value output from the d-axis current command value calculation unit 3b, as well as the d-axis current measurement value output from the power converter current dq conversion unit 2g, and outputs the difference between the two (d-axis current deviation).

[0035] The calculation unit 3d receives the reactive power / voltage control command value output from the reactive power / voltage control command value calculation unit 203, as well as the active power and the reactive power / voltage measurement values ​​output from the reactive power calculation unit 201, and outputs the difference between the two (reactive power / voltage deviation).

[0036] The q-axis current command value calculation unit 3e receives the difference signal output from the calculation unit 3d, calculates the q-axis current command value from the difference signal, and outputs it.

[0037] The calculation unit 3f receives the q-axis current command value output from the q-axis current command value calculation unit 3e, as well as the q-axis current measurement value output from the power converter current dq conversion unit 2g, and outputs the difference between the two (q-axis current deviation).

[0038] The system voltage measurement unit 2a receives a voltage signal supplied from the instrument transformer VT and measures the AC waveform of the system voltage from this signal. For example, this system voltage measurement unit 2a calculates and outputs the numerical value of the three-phase voltage waveform (sine wave) from the voltage signal supplied from the instrument transformer VT.

[0039] The phase calculation unit 2b determines the phase of the AC waveform of the voltage measured by the system voltage measurement unit 2a. This phase calculation unit 2b, for example, converts the three-phase voltage waveform of the voltage to a three-phase to two-phase converter, calculates the phase value, and outputs it. In this example, the phase is determined by a three-phase to two-phase converter, but the phase may be determined by a method other than three-phase to two-phase converter. For example, the phase may be determined by a PLL (phase-locked loop) operation.

[0040] The phase adjustment unit 11 adjusts the phase of the voltage obtained by the phase calculation unit 2b as needed. The phase adjustment unit 11, for example, applies a first-order lag calculation of angular velocity to the phase adjustment and outputs a value (for example, a phase value (θlag) obtained by multiplying the difference (ωdif) between the angular velocity value (ω) of the output (θ) of the phase calculation unit 2b and the first-order lag value of the angular velocity (ωlag) by a coefficient (K) and time (Δt). The phase adjustment unit 11 performs the following calculations, for example, to obtain the adjusted phase value (θlag).

[0041] ω = θ / Δt (Δt: sampling period) ωlag = ω / (1 + T·s) (T: first-order lag time constant, s: Laplace operator) ωdif=ωlag-ω θlag = K·ωdif·Δt Note that multiplication by the coefficient and / or Δt is not always necessary. When calculating the phase value adjusted using a phase change (e.g., Δθ) instead of angular velocity, multiplication by Δt is unnecessary. Also, when using dimensionless numbers such as pu values ​​for various numerical values, when the value of Δt is constant, or when the coefficient includes the value of Δt and is multiplied accordingly, multiplication by the coefficient and / or Δt can be omitted.

[0042] The voltage command value calculation unit 2c determines a control command value for the power converter 1 based on the phase of the voltage adjusted by the phase adjustment unit 11. For example, the voltage command value calculation unit 2c determines and outputs a voltage command value from the phase of the voltage adjusted by the phase adjustment unit 11 and the d-axis current deviation and q-axis current deviation calculated by the calculation units 3c and 3f.

[0043] The two-phase to three-phase conversion unit 2d generates an AC waveform of the control command value obtained by the voltage command value calculation unit 2c by converting the control command value between two phases and three phases. For example, the two-phase to three-phase conversion unit 2d converts the voltage command value obtained by the voltage command value calculation unit 2c into a command value for a three-phase voltage waveform and outputs it (for example, it calculates and outputs the values ​​obtained by converting the α-axis voltage command value and the β-axis voltage command value into three-phase AC). The command values ​​for the three-phase voltage waveform generated by the two-phase to three-phase conversion unit 2d are sent to the U-phase signal generation unit 5A, the V-phase signal generation unit 5B, and the W-phase signal generation unit 5C, respectively, for the U-phase, V-phase, and W-phase.

[0044] The U-phase signal generation unit 5A, the V-phase signal generation unit 5B, and the W-phase signal generation unit 5C each generate U-phase, V-phase, and W-phase signals from the command value and carrier waveform of the three-phase AC voltage waveform generated by the two-phase to three-phase conversion unit 2d, and supply the generated signals to the power converter 1 to control the input and output of the power converter 1.

[0045] The individual functions constituting such a power control device 2 may be implemented as hardware, or some or all of them may be implemented as software (a program to be implemented by a computer).

[0046] Next, we will explain the differences between the power converter 3 of this embodiment and the conventional power converter 3.

[0047] Figures 4 to 6 are simplified conceptual diagrams showing examples of the configuration of a charging and discharging facility with a power conversion device according to the prior art. Figure 4 shows the situation when the grid frequency is stable in the prior art, Figure 5 shows the situation when the grid frequency decreases in the prior art, and Figure 6 shows the situation when the grid frequency increases in the prior art. In Figures 4 to 6, vectors A0, A1, A3, and A10, which indicate the phase angles of the signals at each part, are schematically shown on a rotating coordinate system. The phase angle when the vector on the rotating coordinate system is pointing to the right is 0°. When the vector rotates clockwise, the phase angle becomes a negative value, and when the vector rotates counterclockwise, the phase angle becomes a positive value. Note that in Figures 4 to 6, the same symbols are used for elements common to Figures 1 to 3.

[0048] In this embodiment, a phase adjustment unit 11 is installed as shown in Figures 1 to 3, whereas in the prior art, a phase adjustment unit 11 is not installed as shown in Figures 4 to 6. Therefore, the operation of this embodiment and the prior art differs as described below.

[0049] • During discharge The operation of the power converter 3 during discharge will be explained with reference to Figures 1 to 3 and Figures 4 to 6, comparing this embodiment with the prior art.

[0050] In this embodiment, when the system frequency is stable, the phase angle of the voltage signal of the power system S is, for example, 0°, as shown in vector A0, as shown in Figure 1. At this time, the phase angle of the input signal of the phase adjustment unit 11 (output signal of the phase calculation unit 2b) is 0°, as shown in vector A1, and the phase angle of the output signal of the phase adjustment unit 11 is also 0°, as shown in vector A2.

[0051] This is because the output signal of the phase adjustment unit 11 is not affected by the first-order lag calculation, so the input signal and output signal of the phase adjustment unit 11 have the same phase angle. At this time, the phase angle of the voltage command value output from the voltage command value calculation unit 2c is an angle (e.g., 30°) that is ahead of the phase angle value output from the phase adjustment unit 11 (e.g., 0°) by the angle determined by the control calculation (e.g., 30°), as shown in vector A3. Accordingly, the phase angle of the output voltage of the power converter 1 also becomes 30°, as shown in vector A10. Therefore, the phase difference φ between the grid voltage and the output voltage of the power converter 1 is 30°, and active power proportional to sin(30°) is output (discharged) from the power converter 1.

[0052] In this embodiment, when the system frequency decreases, the phase angle of the voltage signal of the power system S becomes, for example, -30°, as shown by vector A0, as shown in Figure 2.

[0053] At this time, the phase angle of the input signal to the phase adjustment unit 11 (the output signal of the phase calculation unit 2b) also becomes -30° as shown by vector A1. However, the phase angle of the output signal of the phase adjustment unit 11 does not become the same as vector A1, but rather becomes, for example, -15° as shown by vector A2 (the amount of change in the phase angle is smaller for vector A2 than for vector A1).

[0054] This is because the change in the output signal of the phase adjustment unit 11 is a response adjusted by a function using an first-order lag of angular velocity in response to the change in the input signal of the phase adjustment unit 11. If the input signal of the phase adjustment unit 11 continues to change, the amount of change in the output signal of the phase adjustment unit 11 will be smaller than the amount of change in the input signal. Therefore, the phase angle output from the phase adjustment unit 11 will be, for example, -15°, as shown in vector A2. At this time, the phase angle of the voltage command value output from the voltage command value calculation unit 2c will be an angle (for example, 15°) that is ahead of the phase angle of -15° by an angle (for example, 30°) determined by the control calculation, as shown in vector A3. Accordingly, the phase angle of the output voltage of the power converter 1 will also be 15°, as shown in vector A10. Therefore, the phase difference φ between the phase of the grid voltage (-30°) and the phase of the output voltage of the power converter 1 (15°) will be 45°, and active power proportional to sin(45°) will be output (discharged) from the power converter 1.

[0055] When the grid frequency decreases, the phase difference φ (=45°) is greater than the phase difference φ (=30°) when the grid frequency is stable. Therefore, the active power output of power converter 1 is greater when the grid frequency decreases than when the grid frequency is stable. In other words, when the phase of the grid voltage changes due to a decrease in the grid frequency, power converter 1 increases the power it outputs (discharges) to suppress the decrease in grid frequency.

[0056] In this embodiment, when the grid frequency increases, the phases of the grid voltage, the output signal of the phase calculation unit 2b, the output signal of the phase adjustment unit 11, the output signal of the voltage command value calculation unit 2c, and the output voltage of the power converter 1 change in the opposite direction to when the grid frequency decreases. That is, in this embodiment, when the grid frequency increases, the phase difference φ becomes smaller than the phase difference φ when the grid frequency is stable due to the action of the phase adjustment unit 11 described above, and the power output (discharged) from the power converter 1 becomes smaller when the grid frequency increases than when the grid frequency is stable.

[0057] In this embodiment, when the system frequency increases, the phase angle of the voltage signal of the power system S becomes, for example, 30°, as shown in vector A0, as shown in Figure 3.

[0058] At this time, the phase angle of the input signal of the phase adjustment unit 11 (the output signal of the phase calculation unit 2b) also becomes 30° as shown by vector A1. However, the phase angle of the output signal of the phase adjustment unit 11 does not become the same as vector A1, but rather becomes, for example, 15° as shown by vector A2 (the amount of change in the phase angle is smaller for vector A2 than for vector A1).

[0059] This is because the change in the output signal of the phase adjustment unit 11 is a response adjusted by a function using an first-order lag of angular velocity in response to the change in the input signal of the phase adjustment unit 11. If the input signal of the phase adjustment unit 11 continues to change, the amount of change in the output signal of the phase adjustment unit 11 will be smaller than the amount of change in the input signal. Therefore, the phase angle output from the phase adjustment unit 11 will be, for example, 15°, as shown in vector A2.

[0060] At this time, the phase angle of the voltage command value output from the voltage command value calculation unit 2c is an angle (e.g., 45°) that is ahead of the phase angle of the grid voltage (15°, A0) by an angle determined by the control calculation (e.g., 30°), as shown in vector A3. Accordingly, the phase angle of the output voltage of the power converter 1 also becomes 45°, as shown in vector A10. Therefore, the phase difference φ between the phase of the grid voltage (30°) and the phase of the output voltage of the power converter 1 (45°) becomes 15°, and active power proportional to sin(15°) is output (discharged) from the power converter 1.

[0061] The phase difference φ (=15°) when the grid frequency increases is smaller than the phase difference φ (=30°) when the grid frequency is stable. Therefore, the active power output of power converter 1 is smaller when the grid frequency increases than when the grid frequency is stable. In other words, when the phase of the grid voltage changes due to an increase in the grid frequency, power converter 1 reduces the power it outputs (discharges) to suppress the increase in grid frequency.

[0062] On the other hand, in the prior art, when the system frequency is stable, the phase angles shown by vectors A0, A1, A3, and A10 are the same as when the system frequency is stable in the embodiment described in Figure 1, as shown in Figure 4. However, when the system frequency decreases in the prior art, as shown in Figure 5, the phase angles shown by vectors A1, A3, and A10 are different from the phase angles when the system frequency decreases in the embodiment described in Figure 2, because there is no phase adjustment unit 11.

[0063] In the conventional technology, when the system frequency decreases, the phase angle of the voltage signal of the power system S becomes, for example, -30°, as shown by vector A0, as shown in Figure 5.

[0064] At this time, the phase angle output from the phase calculation unit 2b is -30°, as shown in vector A1. The phase angle of the voltage command value output from the voltage command value calculation unit 2c is an angle that is ahead of the phase angle of -30° by an angle determined by the control calculation (for example, 30°) (for example, 0°), as shown in vector A3. Accordingly, the phase angle of the output voltage of the power converter 1 also becomes 0°, as shown in vector A10. Therefore, the phase difference φ between the phase of the grid voltage (-30°) and the phase of the output voltage of the power converter 1 (0°) is 30°, and active power proportional to sin(30°) is output (discharged) from the power converter 1.

[0065] In other words, in the conventional technology, when the grid frequency decreases, even if the phase of the grid voltage changes, the phase within the power control device 2 follows the phase of the grid voltage. Therefore, the phase difference φ between the grid voltage and the output voltage of the power converter 1 remains unchanged, as it does not affect the power output (discharge) from the power converter 1. Thus, the decrease in grid frequency is not suppressed.

[0066] In the conventional technology, when the system frequency increases, the phase angle of the voltage signal of the power system S becomes, for example, 30°, as shown by vector A0, as shown in Figure 6.

[0067] At this time, the phase angle output from the phase calculation unit 2b is 30°, as shown in vector A1. The phase angle of the voltage command value output from the voltage command value calculation unit 2c is an angle that is ahead of the phase angle of 30° by an angle determined by the control calculation (for example, 30°) (for example, 60°), as shown in vector A3. Accordingly, the phase angle of the output voltage of the power converter 1 is also 60°, as shown in vector A10. Therefore, the phase difference φ between the grid voltage and the output voltage of the power converter 1 is 30°, and active power proportional to sin(30°) is output (discharged) from the power converter 1.

[0068] In other words, in the conventional technology, when the grid frequency increases, even if the phase of the grid voltage changes, the phase within the power control device 2 follows the phase of the grid voltage. Therefore, the phase difference φ between the grid voltage and the output voltage of the power converter 1 remains unchanged, as it does not change when the grid frequency is stable, and the power output (discharged) from the power converter 1 does not change. Thus, it does not suppress the increase in grid frequency.

[0069] • When charging Next, the operation of the power converter 3 while it is charging will be explained, comparing this embodiment with the prior art. Illustrations are omitted here.

[0070] When power converter 3 is charging, the relationship between the phase lead and phase lag between the grid voltage and the output voltage of power converter 3 is reversed compared to when it is discharging.

[0071] In other words, in this embodiment, when the grid frequency decreases, the phase difference φ becomes smaller than the phase difference φ when the grid frequency is stable due to the action of the phase adjustment unit 11 described above, and the power input (charged) to the power converter 1 becomes smaller when the grid frequency decreases than when the grid frequency is stable. That is, when the phase of the grid voltage changes due to a decrease in the grid frequency, the power converter 1 reduces the power input (charged) to suppress the decrease in grid frequency.

[0072] Furthermore, in this embodiment, when the grid frequency increases, the phase difference φ becomes larger than the phase difference φ when the grid frequency is stable due to the action of the phase adjustment unit 11 described above, and the power input (charged) to the power converter 1 becomes larger when the grid frequency increases than when the grid frequency is stable. In other words, when the phase of the grid voltage changes due to an increase in the grid frequency, the power converter 1 increases the power input (charged) to suppress the increase in the grid frequency.

[0073] On the other hand, in conventional technology, when the grid frequency decreases, even if the phase of the grid voltage changes, the phase within the power control device 2 follows the phase of the grid voltage. Therefore, the phase difference φ between the grid voltage and the output voltage of the power converter 1 remains unchanged, as it does not affect the power input (charge) from the power converter 1.

[0074] In conventional technology, even when the grid frequency increases or the phase of the grid voltage changes, the phase within the power control device 2 follows the phase of the grid voltage. Therefore, the phase difference φ between the grid voltage and the output voltage of the power converter 1 remains unchanged, as it does not affect the power input (charge) from the power converter 1.

[0075] In the above example, we showed a case where the voltage waveform (sine wave) is converted from three to two phases to obtain the voltage phase, and a first-order lag calculation of angular velocity is used for phase adjustment. However, the phase of an electrical quantity other than voltage (power, current, etc.) may also be used. Furthermore, although the above example showed how to obtain the phase by three-phase to two-phase conversion, the phase may also be obtained by methods other than three-phase to two-phase conversion. For example, the phase may be obtained by PLL (phase-locked loop) calculation. In addition, calculations (functions) other than the first-order lag calculation may be used for phase adjustment. For example, a PLL (phase-locked loop) calculation with adjusted tracking speed or a second-order lag calculation may be used, or the same effect as the first-order lag can be obtained by using a function that fixes the phase value for a certain period of time and then tracks the phase of the system after that period of time has elapsed. Instead of the phase, the value or change (Δθ) of the trigonometric function of the phase (e.g., cosθ, sinθ) may be obtained and used in various calculations.

[0076] Next, an example of the operation of the power control device 2 according to the first embodiment will be described with reference to the flowchart in Figure 7A.

[0077] In the power control device 2, the system voltage measurement unit 2a receives a voltage signal supplied from the instrument transformer VT and measures the AC waveform of the system voltage from this signal (step S1). This system voltage measurement unit 2a, for example, obtains and outputs a numerical value of the three-phase voltage waveform (sine wave) from the voltage signal supplied from the instrument transformer VT.

[0078] Next, the phase calculation unit 2b determines the phase of the AC waveform of the voltage measured by the system voltage measurement unit 2a (step S2). This phase calculation unit 2b, for example, converts the three-phase voltage waveform of the voltage to a three-phase two-phase converter, calculates the phase value, and outputs it.

[0079] Next, the phase adjustment unit 11 adjusts the phase of the voltage obtained by the phase calculation unit 2b (step S3A). The phase adjustment unit 11, for example, obtains and outputs a value obtained by applying a first-order lag calculation of angular velocity to the phase adjustment (for example, a phase adjusted using a value obtained by multiplying the difference between the angular velocity value of the output of the phase calculation unit 2b and the first-order lag value of angular velocity by a coefficient as needed).

[0080] Next, the voltage command value calculation unit 2c determines a control command value for the power converter 1 based on the phase adjusted by the phase adjustment unit 11 (step S3B). The voltage command value calculation unit 2c determines and outputs a voltage command value from, for example, the phase adjusted by the phase adjustment unit 11 and the d-axis current deviation and q-axis current deviation calculated by the calculation units 3c and 3f.

[0081] The d-axis current deviation and q-axis current deviation used by the voltage command value calculation unit 2c are generated by performing calculations and other processing in the power converter current measurement unit 2f, power converter current dq conversion unit 2g, calculation unit 3a, d-axis current command value calculation unit 3b, calculation unit 3c, calculation unit 3d, q-axis current command value calculation unit 3e, and calculation unit 3f, based on the active power measurement value and reactive power / voltage measurement value sent from the active power / reactive power calculation unit 201, the active power control command value sent from the active power control command value calculation unit 202, the reactive power / voltage control command value sent from the reactive power / voltage control command value calculation unit 203, and the current signal sent from the current transformer CT1.

[0082] Next, the two-phase to three-phase conversion unit 2d generates an AC waveform of the control command value obtained by the voltage command value calculation unit 2c by converting the control command value between two phases and three phases (step S4). This two-phase to three-phase conversion unit 2d, for example, converts the voltage command value obtained by the voltage command value calculation unit 2c into a command value for a three-phase voltage waveform and outputs it (for example, it obtains and outputs values ​​obtained by converting the α-axis voltage command value and the β-axis voltage command value into three-phase AC).

[0083] The command values ​​of the three-phase AC generated by the two-phase to three-phase conversion unit 2d are sent to the U-phase signal generation unit 5A, the V-phase signal generation unit 5B, and the W-phase signal generation unit 5C, respectively, to generate signals for the U-phase, V-phase, and W-phase. These signals are then supplied to the power converter 1, and the input and output of the power converter 1 are controlled.

[0084] As a result, for example, when the power converter 3 is discharging, if the grid frequency decreases, the phase difference φ between the grid voltage and the output voltage of the power converter 1 increases, causing the power converter 1 to increase the power output (discharge) and suppress the decrease in grid frequency. On the other hand, if the grid frequency increases, the phase difference φ between the grid voltage and the output voltage of the power converter 1 decreases, causing the power converter 1 to decrease the power output (discharge) and suppress the increase in grid frequency.

[0085] Furthermore, when the power converter 3 is charging, if the grid frequency decreases, the phase difference φ between the grid voltage and the output voltage of the power converter 1 decreases, causing the power converter 1 to reduce the input (charging) power and suppress the decrease in grid frequency. On the other hand, if the grid frequency increases, the phase difference φ between the grid voltage and the output voltage of the power converter 1 increases, causing the power converter 1 to increase the input (charging) power and suppress the increase in grid frequency.

[0086] According to the first embodiment, when the phase of an electrical quantity such as the system voltage fluctuates due to frequency fluctuations in an AC electrical circuit such as a power system S, even if the input / output command value (active power control command value, etc.) of the power converter 3 remains constant, the phase adjustment unit 11 adjusts the phase of the voltage determined by the phase calculation unit 2b, thereby changing the difference between the phase of the electrical quantity (voltage, current, power, etc.) input / output to the power converter 3 and the phase of the electrical quantity (voltage, current, power, etc.) of the electrical circuit such as the power system S, making it possible to change the input / output of the power converter 1.

[0087] This makes it possible to achieve operation similar to the inertial response in synchronous machines (simulation of inertial response), thereby suppressing frequency fluctuations and oscillations in power systems and electrical circuits, and contributing to frequency stabilization of power systems and electrical circuits.

[0088] Here, referring to the graph in Figure 7B, we will explain an example of the changes in the system voltage and the output of power converter 1, and the changes in the active power discharged by power converter 1 to the power system S, when the system frequency decreases. Note that while this example shows the case when the system frequency decreases, when the system frequency increases, the phase difference and active power change in the opposite direction to when the system frequency decreases.

[0089] Figure 7B(a) shows the waveform W1 of the grid frequency, Figure 7B(b) shows the waveform W2 of the phase difference between the grid voltage and the output voltage of power converter 1, and Figure 7B(c) shows the waveform W3 of the active power discharged by power converter 1 to the power system S.

[0090] In addition, Figures 7B(b) and 7B(c) also show the waveform W200 of the phase difference between the grid voltage and the output voltage of a typical power converter (when the phase difference is 0°), and the waveform W300 of the active power discharged by a typical power converter to the power system S (when the command value is 0), so that the behavior of a typical power converter can also be understood.

[0091] For example, consider the case where the grid frequency decreases from 50 Hz, as shown in waveform W1 in Figure 7B(a). When the grid frequency decreases, the phase difference between the grid voltage and the output voltage of the power converter 1 increases due to the action of the phase adjustment unit 11 described above, as shown in waveform W2 in Figure 7B(b). As the phase difference increases, the active power output by the power converter 1 to the power system S increases, as shown in waveform W3 in Figure 7B(c), and the decrease in grid frequency is suppressed.

[0092] When the decrease in grid frequency is suppressed and the grid frequency becomes constant, the phase difference stops increasing, as shown in waveform W2 in Figure 7B(b), and decreases, quickly returning to its original value (the value before the grid frequency decreased). Consequently, as shown in waveform W3 in Figure 7B(c), the active power also stops increasing, decreases, and quickly returns to its original value (the value before the grid frequency decreased).

[0093] In other words, as the frequency decreases, the phase difference increases and the active power increases, and when the frequency becomes constant, the phase difference decreases and the active power decreases. This behavior is the same as the inertial response of a synchronous machine, where the output increases as the frequency decreases and the phase difference decreases and the active power decreases when the frequency becomes constant.

[0094] On the other hand, in the case of a typical power converter, when the grid frequency decreases, the phase of the output voltage follows the grid voltage, so the phase difference between the grid voltage and the output voltage of the power converter remains constant (constant at 0° in the example of Figure 7B(b)), as shown by waveform W200 in Figure 7B(b). Since the phase difference is constant and the active power output by the power converter to the power system S remains constant (constant at 0 in the example of Figure 7B(c)), as shown by waveform W300 in Figure 7B(c), it does not contribute to suppressing the decrease in grid frequency.

[0095] According to this embodiment, waveforms W2 and W3 with good responsiveness can be formed as shown in Figures 7B(b) and (c). One reason for this is that the phase of the voltage measured by the system voltage measurement unit 2a is determined, and then the phase is adjusted using the result of a first-order lag calculation of the angular velocity. If a first-order lag calculation is used on a sinusoidal waveform without determining the phase, the effect of the first-order lag extends to components other than the phase (such as amplitude), making it difficult to form good waveforms such as those shown in waveforms W2 and W3. Also, if a first-order lag calculation is used on the phase value instead of the angular velocity, even if the frequency is constant, a steady difference will occur between the value before and after the first-order lag calculation, making it difficult to form good waveforms such as those shown in waveforms W2 and W3.

[0096] As described above, according to this embodiment, for example, if the grid frequency decreases, it is possible to increase the phase difference and active power necessary to suppress the decrease, thereby stabilizing the grid frequency early. Furthermore, after the grid frequency stabilizes, the phase difference returns to its original value quickly without fluctuation, and the active power also returns to its original value quickly without fluctuation, thus preventing the grid frequency from becoming unstable again after stabilization. Needless to say, if the grid frequency increases, although the direction of behavior is different, similar effects and advantages as when the grid frequency decreases can be obtained.

[0097] The waveforms W2 and W3 described above can be adjusted to a desired shape by appropriately applying a phase-adjusting function to the calculation processing performed in the phase adjustment unit 11 (or in the phase adjustment units 21, 32, 41-43, or 52 in each embodiment described later).

[0098] [Second Embodiment] Next, a second embodiment will be described. In the following, the explanation of parts common to the first embodiment will be omitted, and the focus will be on the differences.

[0099] Figures 8 to 10 are conceptual diagrams showing examples of the configuration of a charging and discharging equipment having a power conversion device according to the second embodiment. Figure 8 shows the situation when the grid frequency is stable in this embodiment, Figure 9 shows the situation when the grid frequency decreases in this embodiment, and Figure 10 shows the situation when the grid frequency increases in this embodiment.

[0100] In the first embodiment described above, an example was shown in which the phase adjustment unit (phase adjustment means) 11 is arranged in the path connecting the phase calculation unit 2b and the voltage command value calculation unit 2c within the power control device 2. In this second embodiment, however, an example is shown in which the phase adjustment unit (phase adjustment means) 21 is arranged in the path connecting the voltage command value calculation unit 2c and the two-phase to three-phase conversion unit 2d. Since the phase adjustment unit 21 is used instead of the phase adjustment unit 11, the processing content and operation of the phase adjustment unit 21 differ from those of the phase adjustment unit 11 in the first embodiment.

[0101] The voltage command value calculation unit 2c determines a control command value for the power converter 1 based on the voltage phase determined by the phase calculation unit 2b. For example, the voltage command value calculation unit 2c determines and outputs a voltage command value from the voltage phase determined by the phase calculation unit 2b and the d-axis current deviation and q-axis current deviation calculated by the calculation units 3c and 3f.

[0102] The phase adjustment unit 21 adjusts the phase of the voltage command value obtained by the voltage command value calculation unit 2c as needed. For example, the phase adjustment unit 21 obtains a value obtained by applying a first-order lag calculation to the phase adjustment (for example, the phase adjusted using a value obtained by multiplying the difference between the angular velocity value of the output of the phase calculation unit 2b and the first-order lag value of the angular velocity by a coefficient as needed), and uses this value to adjust the phase of the control command value (output of the voltage command value calculation unit 2c) and output it.

[0103] The two-phase to three-phase conversion unit 2d generates an AC waveform of a control command value by converting the phase of the control command value, which has been phase-adjusted by the phase adjustment unit 21, into a three-phase waveform. This two-phase to three-phase conversion unit 2d, for example, converts the voltage command value, whose phase has been adjusted by the phase adjustment unit 21, into a three-phase voltage waveform command value and outputs it (for example, it obtains and outputs values ​​obtained by converting the α-axis voltage command value and β-axis voltage command value into three-phase AC voltage command values).

[0104] • During discharge The operation of the power converter 3 while it is discharging will be explained with reference to Figures 8 to 10.

[0105] In this embodiment, when the system frequency is stable, the phase angle of the voltage signal of the power system S is, for example, 0°, as shown in vector A0, as shown in Figure 8. At this time, the phase angle output from the phase calculation unit 2b is also 0°, as shown in vector A1. The phase angle of the voltage command value output from the voltage command value calculation unit 2c is an angle that is advanced by an angle determined by control calculation (for example, 30°) from the phase angle of 0° output from the phase calculation unit 2b (for example, 30°), as shown in vector A3. The phase angle of the output signal of the phase adjustment unit 21 is also 30°, as shown in vector A4.

[0106] This is because the output signal of the phase adjustment unit 21 is not affected by the first-order lag calculation, so the input signal and output signal of the phase adjustment unit 21 have the same phase angle. Consequently, the phase angle of the output voltage of the power converter 1 also becomes 30°, as shown in vector A10. Therefore, the phase difference φ between the grid voltage and the output voltage of the power converter 1 is 30°, and active power proportional to sin(30°) is output (discharged) from the power converter 1.

[0107] In this embodiment, when the system frequency decreases, the phase angle of the voltage signal of the power system S becomes, for example, -30°, as shown in vector A0, as shown in Figure 9.

[0108] At this time, the phase angle output from the phase calculation unit 2b is also -30°, as shown in vector A1. The phase angle of the voltage command value output from the voltage command value calculation unit 2c is an angle (e.g., 0°) that is ahead of the phase angle -30° output from the phase calculation unit 2b by an angle determined by control calculation (e.g., 30°), as shown in vector A3. However, the phase angle of the output signal of the phase adjustment unit 21 is not the same as vector A3, but is, for example, 15°, as shown in vector A4. Consequently, the phase angle of the output voltage of the power converter 1 is also 15°, as shown in vector A10. Therefore, the phase difference φ between the grid voltage and the output voltage of the power converter 1 is 45°, and active power proportional to sin(45°) is output (discharged) from the power converter 1.

[0109] When the grid frequency decreases, the phase difference φ (=45°) is greater than the phase difference φ (=30°) when the grid frequency is stable. Therefore, the active power output of power converter 1 is greater when the grid frequency decreases than when the grid frequency is stable. In other words, when the phase of the grid voltage changes due to a decrease in the grid frequency, power converter 1 increases the power it outputs (discharges) to suppress the decrease in grid frequency.

[0110] In this embodiment, when the system frequency increases, the phase angle of the voltage signal of the power system S becomes, for example, 30°, as shown in vector A0, as shown in Figure 10.

[0111] At this time, the phase angle output from the phase calculation unit 2b is also 30°, as shown in vector A1. The phase angle of the voltage command value output from the voltage command value calculation unit 2c is an angle (e.g., 60°) that is ahead of the phase angle of 30° output from the phase calculation unit 2b by an angle determined by control calculation (e.g., 30°), as shown in vector A3. However, the phase angle of the output signal of the phase adjustment unit 21 is not the same as vector A3, but is, for example, 45°, as shown in vector A4. Consequently, the phase angle of the output voltage of the power converter 1 is also 45°, as shown in vector A10. Therefore, the phase difference φ between the grid voltage and the output voltage of the power converter 1 is 15°, and active power proportional to sin(15°) is output (discharged) from the power converter 1.

[0112] The phase difference φ (=15°) when the grid frequency increases is smaller than the phase difference φ (=30°) when the grid frequency is stable. Therefore, the active power output of power converter 1 is smaller when the grid frequency increases than when the grid frequency is stable. In other words, when the phase of the grid voltage changes due to an increase in the grid frequency, power converter 1 reduces the power it outputs (discharges) to suppress the increase in grid frequency.

[0113] • When charging When the power converter 3 is charging, as explained in the embodiment described above, the relationship between the phase lead and phase lag between the grid voltage and the output voltage of the power converter 3 is reversed compared to when it is discharging.

[0114] In other words, in this embodiment, when the grid frequency decreases, the phase difference φ becomes smaller than the phase difference φ when the grid frequency is stable due to the action of the phase adjustment unit 21 described above, and the power input (charged) to the power converter 1 becomes smaller when the grid frequency decreases than when the grid frequency is stable. That is, when the phase of the grid voltage changes due to a decrease in the grid frequency, the power converter 1 reduces the power input (charged) to suppress the decrease in grid frequency.

[0115] Furthermore, in this embodiment, when the grid frequency increases, the phase difference φ becomes larger than the phase difference φ when the grid frequency is stable due to the action of the phase adjustment unit 21 described above, and the power input (charged) to the power converter 1 becomes larger when the grid frequency increases than when the grid frequency is stable. In other words, when the phase of the grid voltage changes with an increase in the grid frequency, the power converter 1 increases the power input (charged) to suppress the increase in the grid frequency.

[0116] Next, an example of the operation of the power control device 2 according to the second embodiment will be described with reference to the flowchart in Figure 11.

[0117] In the power control device 2, the system voltage measurement unit 2a receives a voltage signal supplied from the instrument transformer VT and measures the AC waveform of the system voltage from this signal (step S1). This system voltage measurement unit 2a, for example, obtains and outputs a numerical value of the three-phase voltage waveform (sine wave) from the voltage signal supplied from the instrument transformer VT.

[0118] Next, the phase calculation unit 2b determines the phase of the voltage measured by the system voltage measurement unit 2a (step S2). This phase calculation unit 2b, for example, converts the three-phase voltage waveform of the voltage into a three-phase two-phase waveform, calculates the phase value, and outputs it.

[0119] Next, the voltage command value calculation unit 2c determines a control command value for the power converter 1 based on the voltage phase determined by the phase calculation unit 2b (step S3). The voltage command value calculation unit 2c determines and outputs a voltage command value from, for example, the voltage phase determined by the phase calculation unit 2b and the d-axis current deviation and q-axis current deviation calculated by the calculation units 3c and 3f.

[0120] Next, the phase adjustment unit 21 adjusts the phase of the voltage command value obtained by the voltage command value calculation unit 2c (step S4A). The phase adjustment unit 21, for example, obtains a value obtained by applying a first-order lag calculation to the phase adjustment (for example, the phase adjusted using a value obtained by multiplying the difference between the angular velocity value of the output of the phase calculation unit 2b and the first-order lag value of the angular velocity by a coefficient as needed), and uses this value to adjust the phase of the control command value (output of the voltage command value calculation unit 2c) and output it.

[0121] Next, the two-phase to three-phase conversion unit 2d generates the AC waveform of the control command value by converting the voltage command value, whose phase has been adjusted by the phase adjustment unit 21, into a two-phase to three-phase converter (step S4B). The two-phase to three-phase conversion unit 2d, for example, converts the voltage command value, whose phase has been adjusted by the phase adjustment unit 21, into a command value for a three-phase voltage waveform and outputs it (for example, it obtains and outputs values ​​obtained by converting the α-axis voltage command value and the β-axis voltage command value into a three-phase AC voltage command value).

[0122] The command values ​​of the three-phase voltage waveforms generated by the two-phase to three-phase conversion unit 2d are sent to the U-phase signal generation unit 5A, the V-phase signal generation unit 5B, and the W-phase signal generation unit 5C, respectively, to generate signals for the U-phase, V-phase, and W-phase. These signals are then supplied to the power converter 1, and the input and output of the power converter 1 are controlled.

[0123] As a result, for example, when the power converter 3 is discharging, if the grid frequency decreases, the phase difference φ between the grid voltage and the output voltage of the power converter 1 increases, causing the power converter 1 to increase the power output (discharge) and suppress the decrease in grid frequency. On the other hand, if the grid frequency increases, the phase difference φ between the grid voltage and the output voltage of the power converter 1 decreases, causing the power converter 1 to decrease the power output (discharge) and suppress the increase in grid frequency.

[0124] Furthermore, when the power converter 3 is charging, if the grid frequency decreases, the phase difference φ between the grid voltage and the output voltage of the power converter 1 decreases, causing the power converter 1 to reduce the input (charging) power and suppress the decrease in grid frequency. On the other hand, if the grid frequency increases, the phase difference φ between the grid voltage and the output voltage of the power converter 1 increases, causing the power converter 1 to increase the input (charging) power and suppress the increase in grid frequency.

[0125] According to the second embodiment, when the phase of electrical quantities such as system voltage fluctuates due to frequency fluctuations in AC electrical circuits such as power systems S, even if the input / output command values ​​(active power control command values, etc.) of the power converter 3 remain constant, the phase adjustment unit 21 adjusts the phase of the voltage command value calculated by the voltage command value calculation unit 2c, thereby changing the difference between the phase of the electrical quantities (voltage, current, power, etc.) input and output to the power converter 3 and the phase of the electrical quantities (voltage, current, power, etc.) of electrical circuits such as power systems S, and making it possible to change the input and output of the power converter 1.

[0126] This makes it possible to achieve operation similar to the inertial response in synchronous machines (simulation of inertial response), thereby suppressing frequency fluctuations and oscillations in power systems and electrical circuits, and contributing to frequency stabilization of power systems and electrical circuits.

[0127] [Third Embodiment] Next, a third embodiment will be described. In the following, the explanation of parts common to the first embodiment will be omitted, and the focus will be on the differences.

[0128] Figure 12 is a conceptual diagram showing an example of the configuration of a charging and discharging facility having a power conversion device according to the third embodiment. This Figure 12 shows the situation when the grid frequency decreases in this embodiment. The situation when the grid frequency is stable and the situation when the grid frequency increases in this embodiment can be easily inferred from the descriptions of each embodiment described above, so their illustrations and explanations are omitted.

[0129] In the first embodiment described above, an example was shown in which the phase adjustment unit (phase adjustment means) 11 is arranged in the path connecting the phase calculation unit 2b and the voltage command value calculation unit 2c within the power control device 2. However, in this third embodiment, an example is shown in which the three-phase to two-phase conversion unit 31 and the phase adjustment unit (phase adjustment means) 32 are arranged in the path connecting the grid voltage measurement unit 2a and the phase calculation unit 2b. Since the three-phase to two-phase conversion unit 31 and the phase adjustment unit 32 are used instead of the phase adjustment unit 11, the processing content and operation of the phase calculation unit 2b and the phase adjustment unit 32 differ from those in the first embodiment.

[0130] The three-phase to two-phase conversion unit 31 converts the AC waveform of the voltage measured by the system voltage measurement unit 2a into three-phase to two-phase. This three-phase to two-phase conversion unit 31, for example, performs αβ conversion on the three-phase voltage waveform of the voltage and outputs the values ​​of the α-axis voltage, β-axis voltage, and phase. In this example, an example of αβ conversion is shown, but other methods may be used. For example, dq conversion may be used.

[0131] The phase adjustment unit 32 adjusts the phase of the voltage obtained by the three-phase to two-phase conversion unit 31 as needed. For example, the phase adjustment unit 32 obtains a value obtained by applying a first-order lag calculation of angular velocity to the phase adjustment (for example, a value obtained by multiplying the difference between the angular velocity value of the phase of the output of the three-phase to two-phase conversion unit 31 and the first-order lag value of angular velocity by a coefficient as needed, and adjusts the phase of the α-axis voltage and β-axis voltage using this value and outputs it.

[0132] The phase calculation unit 2b determines the phase of a voltage from a voltage whose phase has been adjusted by the phase adjustment unit 32. This phase calculation unit 2b, for example, calculates and outputs the phase value from the phase-adjusted α-axis voltage and β-axis voltage.

[0133] The voltage command value calculation unit 2c determines a control command value for the power converter 1 based on the voltage phase determined by the phase calculation unit 2b. For example, the voltage command value calculation unit 2c determines and outputs a voltage command value from the phase determined by the phase calculation unit 2b and the d-axis current deviation and q-axis current deviation calculated by the calculation units 3c and 3f.

[0134] • During discharge The operation of the power converter 3 while it is discharging will be explained with reference to Figure 12.

[0135] In this embodiment, when the grid frequency is stable, although not shown in the figures, the output signal of the phase adjustment unit 32 is not affected by the first-order lag calculation, so the input signal and output signal of the phase adjustment unit 32 have the same phase angle. In this case, as in the embodiments described above, the phase difference φ between the grid voltage and the output voltage of the power converter 1 is, for example, 30°, and active power proportional to sin(30°) is output (discharged) from the power converter 1.

[0136] In this embodiment, when the system frequency decreases, the phase angle of the voltage signal of the power system S becomes, for example, -30°, as shown in vector A0, as shown in Figure 12.

[0137] At this time, the phase angle output from the three-phase to two-phase conversion unit 31 is -30°, as shown in vector A21. However, the phase angle of the output signal from the phase adjustment unit 32 is not the same as vector A21, but rather -15°, as shown in vector A22. The phase angle output from the phase calculation unit 2b is also -15°, as shown in vector A1. The phase angle of the voltage command value output from the voltage command value calculation unit 2c is an angle (e.g., 15°) that is ahead of the phase angle -15° output from the phase calculation unit 2b by an angle determined by control calculation (e.g., 30°), as shown in vector A3. Consequently, the phase angle of the output voltage of the power converter 1 is also 15°, as shown in vector A10. Therefore, the phase difference φ between the grid voltage and the output voltage of the power converter 1 is 45°, and active power proportional to sin(45°) is output (discharged) from the power converter 1.

[0138] When the grid frequency decreases, the phase difference φ (=45°) is greater than the phase difference φ (=30°) when the grid frequency is stable. Therefore, the active power output of power converter 1 is greater when the grid frequency decreases than when the grid frequency is stable. In other words, when the phase of the grid voltage changes due to a decrease in the grid frequency, power converter 1 increases the power it outputs (discharges) to suppress the decrease in grid frequency.

[0139] In this embodiment, when the system frequency increases, although not shown in the figures, if the phase angle of the voltage signal of the power system S shown by vector A0 becomes, for example, 30°, then, as in the embodiments described above, the phase angle of the output voltage of the power converter 1 shown by vector A10 becomes 45°. Therefore, the phase difference φ between the system voltage and the output voltage of the power converter 1 is 15°, and active power proportional to sin(15°) is output (discharged) from the power converter 1.

[0140] The phase difference φ (=15°) when the grid frequency increases is smaller than the phase difference φ (=30°) when the grid frequency is stable. Therefore, the active power output of power converter 1 is smaller when the grid frequency increases than when the grid frequency is stable. In other words, when the phase of the grid voltage changes due to an increase in the grid frequency, power converter 1 reduces the power it outputs (discharges) to suppress the increase in grid frequency.

[0141] • When charging When the power converter 3 is charging, as explained in the embodiment described above, the relationship between the phase lead and phase lag between the grid voltage and the output voltage of the power converter 3 is reversed compared to when it is discharging.

[0142] In other words, in this embodiment, when the grid frequency decreases, the phase difference φ becomes smaller than the phase difference φ when the grid frequency is stable due to the action of the phase adjustment unit 32 described above, and the power input (charged) to the power converter 1 becomes smaller when the grid frequency decreases than when the grid frequency is stable. That is, when the phase of the grid voltage changes due to a decrease in the grid frequency, the power converter 1 reduces the power input (charged) to suppress the decrease in grid frequency.

[0143] Furthermore, in this embodiment, when the grid frequency increases, the phase difference φ becomes larger than the phase difference φ when the grid frequency is stable due to the action of the phase adjustment unit 32 described above, and the power input (charged) to the power converter 1 becomes larger when the grid frequency increases than when the grid frequency is stable. In other words, when the phase of the grid voltage changes with an increase in the grid frequency, the power converter 1 increases the power input (charged) to suppress the increase in the grid frequency.

[0144] Next, an example of the operation of the power control device 2 according to the third embodiment will be described with reference to the flowchart in Figure 13.

[0145] In the power control device 2, the system voltage measurement unit 2a receives a voltage signal supplied from the instrument transformer VT and measures the AC waveform of the system voltage from this signal (step S1). This system voltage measurement unit 2a, for example, obtains and outputs a numerical value of the three-phase voltage waveform (sine wave) from the voltage signal supplied from the instrument transformer VT.

[0146] Next, the three-phase to two-phase conversion unit 31 determines the phase of the voltage measured by the system voltage measurement unit 2a (step S2A). This three-phase to two-phase conversion unit 31, for example, performs αβ conversion on the three-phase voltage waveform of the voltage, and outputs the values ​​of the α-axis voltage, β-axis voltage, and phase.

[0147] Next, the phase adjustment unit 32 adjusts the phase of the voltage obtained by the three-phase to two-phase conversion unit 31 (step S2B). The phase adjustment unit 32, for example, applies a first-order lag calculation of angular velocity to adjust the phase, and obtains a voltage value with a delayed phase (for example, the adjusted phase is obtained by multiplying the difference between the angular velocity value of the phase of the output of the three-phase to two-phase conversion unit 31 and the first-order lag value of the angular velocity by a coefficient as needed), and uses this value to adjust the phase of the α-axis voltage and β-axis voltage and output them.

[0148] Next, the phase calculation unit 2b determines the phase of the voltage from the voltage whose phase has been adjusted by the phase adjustment unit 32 (step S2C). This phase calculation unit 2b, for example, determines and outputs the phase value from the phase-adjusted α-axis voltage and β-axis voltage.

[0149] Next, the voltage command value calculation unit 2c determines a control command value for the power converter 1 based on the voltage phase determined by the phase calculation unit 2b (step S3). This voltage command value calculation unit 2c determines and outputs a voltage command value from, for example, the phase determined by the phase calculation unit 2b and the d-axis current deviation and q-axis current deviation calculated by the calculation units 3c and 3f.

[0150] Next, the two-phase to three-phase conversion unit 2d generates an AC waveform of the control command value obtained by the voltage command value calculation unit 2c by converting the control command value between two phases and three phases (step S4). This two-phase to three-phase conversion unit 2d, for example, converts the voltage command value obtained by the voltage command value calculation unit 2c into a command value for a three-phase voltage waveform and outputs it (for example, it obtains and outputs values ​​obtained by converting the α-axis voltage command value and β-axis voltage command value into three-phase AC command values).

[0151] The command values ​​of the three-phase voltage waveforms generated by the two-phase to three-phase conversion unit 2d are sent to the U-phase signal generation unit 5A, the V-phase signal generation unit 5B, and the W-phase signal generation unit 5C, respectively, to generate signals for the U-phase, V-phase, and W-phase. These signals are then supplied to the power converter 1, and the input and output of the power converter 1 are controlled.

[0152] As a result, for example, when the power converter 3 is discharging, if the grid frequency decreases, the phase difference φ between the grid voltage and the output voltage of the power converter 1 increases, causing the power converter 1 to increase the power output (discharge) and suppress the decrease in grid frequency. On the other hand, if the grid frequency increases, the phase difference φ between the grid voltage and the output voltage of the power converter 1 decreases, causing the power converter 1 to decrease the power output (discharge) and suppress the increase in grid frequency.

[0153] Furthermore, when the power converter 3 is charging, if the grid frequency decreases, the phase difference φ between the grid voltage and the output voltage of the power converter 1 decreases, causing the power converter 1 to reduce the input (charging) power and suppress the decrease in grid frequency. On the other hand, if the grid frequency increases, the phase difference φ between the grid voltage and the output voltage of the power converter 1 increases, causing the power converter 1 to increase the input (charging) power and suppress the increase in grid frequency.

[0154] According to the third embodiment, when the phase of electrical quantities such as the system voltage fluctuates due to frequency fluctuations in AC electrical circuits such as the power system S, even if the input / output command value (active power control command value, etc.) of the power converter 3 remains constant, the three-phase to two-phase conversion unit 31 determines the phase of the voltage measured by the system voltage measurement unit 2a through three-phase to two-phase conversion, and the phase adjustment unit 32 adjusts the phase of the voltage determined by the three-phase to two-phase conversion unit 31. This makes it possible to change the difference between the phase of the electrical quantities (voltage, current, power, etc.) input and output to the power converter 3 and the phase of the electrical quantities (voltage, current, power, etc.) of the electrical circuits such as the power system S, thereby changing the input and output of the power converter 1.

[0155] This makes it possible to achieve operation similar to the inertial response in a synchronous machine (simulation of inertial response), thereby suppressing frequency fluctuations and oscillations in the electrical circuit and contributing to frequency stabilization of the electrical circuit.

[0156] [Fourth Embodiment] Next, a fourth embodiment will be described. In the following, the explanation of parts common to the first embodiment will be omitted, and the focus will be on the differences.

[0157] Figure 14 is a conceptual diagram showing an example of the configuration of a charging and discharging facility having a power conversion device according to the fourth embodiment. This Figure 14 shows the situation when the grid frequency decreases in this embodiment. The situation when the grid frequency is stable and the situation when the grid frequency increases in this embodiment can be easily inferred from the descriptions of each embodiment described above, so their illustrations and explanations are omitted.

[0158] In the first embodiment described above, an example was shown in which the phase adjustment unit (phase adjustment means) 11 is arranged in the path connecting the phase calculation unit 2b and the voltage command value calculation unit 2c within the power control device 2. However, in this fourth embodiment, instead, an example is shown in which phase adjustment units (phase adjustment means) 41 to 43 corresponding to the U phase, V phase, and W phase, respectively, are arranged in the paths connecting the two-phase to three-phase conversion unit 2d and the U phase signal generation unit 5A, the V phase signal generation unit 5B, and the W phase signal generation unit 5C, respectively.

[0159] The phase adjustment units 41 to 43 adjust the phase of the command values ​​of the three-phase voltage waveforms generated by the two-phase to three-phase conversion unit 2d for each of the U-phase, V-phase, and W-phase as needed. These phase adjustment units 41 to 43 obtain a value obtained by applying a first-order lag calculation of angular velocity to the phase adjustment (for example, using a value obtained by multiplying the difference between the angular velocity value output by the phase calculation unit 2b and the first-order lag value of angular velocity by a coefficient as needed, and then use this value to adjust the phase of the voltage command values ​​of the U-phase, V-phase, and W-phase and output them.

[0160] The U-phase signal generation unit 5A, the V-phase signal generation unit 5B, and the W-phase signal generation unit 5C each generate U-phase, V-phase, and W-phase signals from the command value and carrier waveform of the three-phase voltage waveform whose phase has been adjusted by the phase adjustment units 41 to 43, and supply the generated signals to the power converter 1 to control the input and output of the power converter 1.

[0161] • During discharge The operation of the power converter 3 while it is discharging will be explained with reference to Figure 14.

[0162] In this embodiment, when the grid frequency is stable, although not shown in the figures, the output signals of the phase adjustment units 41-43 are not affected by the first-order lag calculation, so the output signal of the two-phase three-phase conversion unit 2d and the output signals of the phase adjustment units 41-43 have the same phase angle. In this case, as in the embodiments described above, the phase difference φ between the grid voltage and the output voltage of the power converter 1 is, for example, 30°, and active power proportional to sin(30°) is output (discharged) from the power converter 1.

[0163] In this embodiment, when the system frequency decreases, the phase angle of the voltage signal of the power system S becomes, for example, -30°, as shown in vector A0, as shown in Figure 14.

[0164] At this time, the phase angle output from the phase calculation unit 2b is also -30°, as shown in vector A1. The phase angle of the voltage command value output from the voltage command value calculation unit 2c is an angle (e.g., 0°) that is ahead of the phase angle -30° output from the phase calculation unit 2b by an angle determined by control calculation (e.g., 30°), as shown in vector A3. The phase angle of the command value of the three-phase voltage waveform output from the two-phase to three-phase conversion unit 2d is 0°, but the phase angle of the output signals of the phase adjustment units 41 to 43 is, for example, 15°. Accordingly, the phase angle of the output voltage of the power converter 1 is also 15°, as shown in vector A10. Therefore, the phase difference φ between the grid voltage and the output voltage of the power converter 1 is 45°, and active power proportional to sin(45°) is output (discharged) from the power converter 1.

[0165] When the grid frequency decreases, the phase difference φ (=45°) is greater than the phase difference φ (=30°) when the grid frequency is stable. Therefore, the active power output of power converter 1 is greater when the grid frequency decreases than when the grid frequency is stable. In other words, when the phase of the grid voltage changes due to a decrease in the grid frequency, power converter 1 increases the power it outputs (discharges) to suppress the decrease in grid frequency.

[0166] In this embodiment, when the system frequency increases, although not shown in the figures, if the phase angle of the voltage signal of the power system S shown by vector A0 becomes, for example, 30°, then, as in the embodiments described above, the phase angle of the output voltage of the power converter 1 shown by vector A10 becomes 45°. Therefore, the phase difference φ between the system voltage and the output voltage of the power converter 1 is 15°, and active power proportional to sin(15°) is output (discharged) from the power converter 1.

[0167] The phase difference φ (=15°) when the grid frequency increases is smaller than the phase difference φ (=30°) when the grid frequency is stable. Therefore, the active power output of power converter 1 is smaller when the grid frequency increases than when the grid frequency is stable. In other words, when the phase of the grid voltage changes due to an increase in the grid frequency, power converter 1 reduces the power it outputs (discharges) to suppress the increase in grid frequency.

[0168] • When charging When the power converter 3 is charging, as explained in the embodiment described above, the relationship between the phase lead and phase lag between the grid voltage and the output voltage of the power converter 3 is reversed compared to when it is discharging.

[0169] In other words, in this embodiment, when the grid frequency decreases, the phase difference φ becomes smaller than the phase difference φ when the grid frequency is stable due to the action of the phase adjustment units 41 to 43 described above, and the power input (charged) to the power converter 1 becomes smaller when the grid frequency decreases than when the grid frequency is stable. That is, when the phase of the grid voltage changes due to a decrease in the grid frequency, the power converter 1 reduces the power input (charged) to suppress the decrease in grid frequency.

[0170] Furthermore, in this embodiment, when the grid frequency increases, the phase difference φ becomes larger than the phase difference φ when the grid frequency is stable due to the action of the phase adjustment units 41 to 43 described above, and the power input (charged) to the power converter 1 becomes larger when the grid frequency increases than when the grid frequency is stable. In other words, when the phase of the grid voltage changes with an increase in the grid frequency, the power converter 1 increases the power input (charged) to suppress the increase in the grid frequency.

[0171] Next, an example of the operation of the power control device 2 according to the fourth embodiment will be described with reference to the flowchart in Figure 15.

[0172] In the power control device 2, the system voltage measurement unit 2a receives a voltage signal supplied from the instrument transformer VT and measures the AC waveform of the system voltage from this signal (step S1). This system voltage measurement unit 2a, for example, obtains and outputs a numerical value of the three-phase voltage waveform (sine wave) from the voltage signal supplied from the instrument transformer VT.

[0173] Next, the phase calculation unit 2b determines the phase of the AC waveform of the voltage measured by the system voltage measurement unit 2a (step S2). This phase calculation unit 2b, for example, converts the three-phase voltage waveform of the voltage to a three-phase two-phase converter, calculates the phase value, and outputs it.

[0174] Next, the voltage command value calculation unit 2c determines a control command value for the power converter 1 based on the voltage phase determined by the phase calculation unit 2b (step S3). The voltage command value calculation unit 2c determines and outputs a voltage command value from, for example, the voltage phase determined by the phase calculation unit 2b and the d-axis current deviation and q-axis current deviation calculated by the calculation units 3c and 3f.

[0175] Next, the two-phase to three-phase conversion unit 2d generates an AC waveform of the control command value obtained by the voltage command value calculation unit 2c by converting the control command value between two phases and three phases (step S4). This two-phase to three-phase conversion unit 2d, for example, converts the voltage command value obtained by the voltage command value calculation unit 2c into a command value for a three-phase voltage waveform and outputs it (for example, it obtains and outputs values ​​obtained by converting the α-axis voltage and β-axis voltage command values ​​into three-phase AC command values).

[0176] Next, the phase adjustment units 41 to 43 adjust the phase of the command values ​​of the three-phase voltage waveforms generated by the two-phase to three-phase conversion unit 2d for each of the U-phase, V-phase, and W-phase (step S5). These phase adjustment units 41 to 43, for example, obtain a value obtained by applying a first-order lag calculation of angular velocity to the phase adjustment (for example, by using a value obtained by multiplying the difference between the angular velocity value output by the phase calculation unit 2b and the first-order lag value of angular velocity by a coefficient as needed to adjust the phase), and use this value to adjust the phase of the voltage command values ​​of the U-phase, V-phase, and W-phase and output them.

[0177] The command values ​​of the three-phase voltage waveforms, whose phases have been adjusted by the phase adjustment units 41-43, are sent to the U-phase signal generation unit 5A, the V-phase signal generation unit 5B, and the W-phase signal generation unit 5C, respectively, to generate signals for the U-phase, V-phase, and W-phase. These signals are then supplied to the power converter 1 to control its input and output.

[0178] As a result, for example, when the power converter 3 is discharging, if the grid frequency decreases, the phase difference φ between the grid voltage and the output voltage of the power converter 1 increases, causing the power converter 1 to increase the power output (discharge) and suppress the decrease in grid frequency. On the other hand, if the grid frequency increases, the phase difference φ between the grid voltage and the output voltage of the power converter 1 decreases, causing the power converter 1 to decrease the power output (discharge) and suppress the increase in grid frequency.

[0179] Furthermore, when the power converter 3 is charging, if the grid frequency decreases, the phase difference φ between the grid voltage and the output voltage of the power converter 1 decreases, causing the power converter 1 to reduce the input (charging) power and suppress the decrease in grid frequency. On the other hand, if the grid frequency increases, the phase difference φ between the grid voltage and the output voltage of the power converter 1 increases, causing the power converter 1 to increase the input (charging) power and suppress the increase in grid frequency.

[0180] According to the fourth embodiment, when the phase of electrical quantities such as system voltage fluctuates due to frequency fluctuations in AC electrical circuits such as power systems S, even if the input / output command values ​​(active power control command values, etc.) of the power converter 3 remain constant, the phase adjustment units 41 to 43 adjust the phase of the command values ​​of the three-phase voltage waveform generated by the two-phase to three-phase conversion unit 2d. This allows the difference between the phase of the electrical quantities (voltage, current, power, etc.) input and output to the power converter 3 and the phase of the electrical quantities (voltage, current, power, etc.) of electrical circuits such as power systems S to be changed, thereby enabling the input and output of the power converter 1 to be changed.

[0181] This makes it possible to achieve operation similar to the inertial response in a synchronous machine (simulation of inertial response), thereby suppressing frequency fluctuations and oscillations in the electrical circuit and contributing to frequency stabilization of the electrical circuit.

[0182] [Fifth Embodiment] Next, a fifth embodiment will be described. In the following, the explanation of parts common to the first embodiment will be omitted, and the focus will be on the differences.

[0183] Figure 16 is a conceptual diagram showing an example of the configuration of a charging and discharging facility having a power conversion device according to the fifth embodiment. This Figure 16 shows the situation when the grid frequency decreases in this embodiment. Note that the situation when the grid frequency is stable and the situation when the grid frequency increases in this embodiment can be easily inferred from the descriptions of each embodiment described above, so their illustrations and explanations are omitted.

[0184] In the first embodiment described above, an example was shown in which the phase adjustment unit (phase adjustment means) 11 is arranged in the path connecting the phase calculation unit 2b and the voltage command value calculation unit 2c within the power control device 2. However, in this fifth embodiment, an example is shown in which the phase measurement unit 51, the phase adjustment unit (phase adjustment means) 52, and the AC waveform generation unit (AC waveform generation means) 53 are arranged in the path connecting the grid voltage measurement unit 2a and the phase calculation unit 2b. Since the voltage phase calculation unit 51, the phase adjustment unit 52, and the AC waveform generation unit 53 are used instead of the phase adjustment unit 11, the processing content and operation of the phase adjustment unit 52 differ from those of the phase adjustment unit 11 in the first embodiment.

[0185] The voltage phase calculation unit 51 determines the phase of the AC waveform of the voltage measured by the system voltage measurement unit 2a. This voltage phase calculation unit 51, for example, converts the three-phase voltage waveform of the voltage to a three-phase to two-phase converter, calculates the phase value, and outputs it. In this example, the phase is determined by a three-phase to two-phase converter, but the phase may be determined by a method other than three-phase to two-phase converter. For example, the phase may be determined by a PLL (phase-locked loop) operation.

[0186] The phase adjustment unit 52 adjusts the phase of the voltage measured by the voltage phase calculation unit 51 as needed. For example, the phase adjustment unit 52 calculates and outputs a value obtained by applying a first-order lag calculation of angular velocity to the phase adjustment (for example, a phase adjusted using a value obtained by multiplying the difference between the angular velocity value output by the phase measurement unit 51 and the first-order lag value of angular velocity by a coefficient).

[0187] The AC waveform generation unit 53 generates a three-phase AC waveform from the phase adjusted by the phase adjustment unit 52. For example, the AC waveform generation unit 53 obtains and outputs a three-phase AC waveform (for example, cos(θαlag), cos(θαlag-2·π / 3), cos(θαlag-4·π / 3)) from the output (phase θαlag) of the phase adjustment unit 32.

[0188] The phase calculation unit 2b determines the phase of the three-phase AC waveform generated by the AC waveform generation unit 53. This phase calculation unit 2b, for example, converts the three-phase AC waveform to a three-phase two-phase waveform, calculates the phase value, and outputs it.

[0189] The voltage command value calculation unit 2c determines a control command value for the power converter 1 based on the phase calculated by the phase calculation unit 2b. For example, the voltage command value calculation unit 2c calculates and outputs a voltage command value from the phase calculated by the phase calculation unit 2b and the d-axis current deviation and q-axis current deviation calculated by the calculation units 3c and 3f.

[0190] • During discharge The operation of the power converter 3 while it is discharging will be explained with reference to Figure 16.

[0191] In this embodiment, when the grid frequency is stable, although not shown in the figures, the output signal of the phase adjustment unit 52 is not affected by the first-order lag calculation, so the input signal and output signal of the phase adjustment unit 52 have the same phase angle. Also, the phase angle of the output signal (three-phase AC) of the AC waveform generation unit 53 and the phase angle of the output signal (phase) of the phase calculation unit 2b are the same as the phase angle of the output signal of the phase adjustment unit 52. In this case, as in the embodiments described above, the phase difference φ between the grid voltage and the output voltage of the power converter 1 is, for example, 30°, and active power proportional to sin(30°) is output (discharged) from the power converter 1.

[0192] In this embodiment, when the system frequency decreases, the phase angle of the voltage signal of the power system S becomes, for example, -30°, as shown in vector A0, as shown in Figure 16.

[0193] At this time, the phase angle of the input signal of the phase adjustment unit 52 (the output signal of the voltage phase calculation unit 51) is -30°, as shown by vector A21. However, the phase angle of the output signal of the phase adjustment unit 52 is not the same as vector A21, but rather, as shown by vector A22, it becomes, for example, -15° (the amount of change in phase angle is smaller for vector A2 than for vector A1). The phase angle of the output signal (three-phase AC) of the AC waveform generation unit 53 is the same as the phase angle of the output signal of the phase adjustment unit 32, so the phase angle output from the phase calculation unit 2b is also -15°, as shown by vector A1. The phase angle of the voltage command value output from the voltage command value calculation unit 2c is, as shown by vector A3, an angle that is advanced by an angle determined by control calculation (for example, 30°) from the phase angle of -15° output from the phase calculation unit 2b (for example, 15°). Consequently, the phase angle of the output voltage of the power converter 1 also becomes 15°, as shown by vector A10. Therefore, the phase difference φ between the grid voltage and the output voltage of power converter 1 is 45°, and active power proportional to sin(45°) will be output (discharged) from power converter 1.

[0194] When the grid frequency decreases, the phase difference φ (=45°) is greater than the phase difference φ (=30°) when the grid frequency is stable. Therefore, the active power output of power converter 1 is greater when the grid frequency decreases than when the grid frequency is stable. In other words, when the phase of the grid voltage changes due to a decrease in the grid frequency, power converter 1 increases the power it outputs (discharges) to suppress the decrease in grid frequency.

[0195] In this embodiment, when the system frequency increases, although not shown in the figures, if the phase angle of the voltage signal of the power system S shown by vector A0 becomes, for example, 30°, then, as in the embodiments described above, the phase angle of the output voltage of the power converter 1 shown by vector A10 becomes 45°. Therefore, the phase difference φ between the system voltage and the output voltage of the power converter 1 is 15°, and active power proportional to sin(15°) is output (discharged) from the power converter 1.

[0196] The phase difference φ (=15°) when the grid frequency increases is smaller than the phase difference φ (=30°) when the grid frequency is stable. Therefore, the active power output of power converter 1 is smaller when the grid frequency increases than when the grid frequency is stable. In other words, when the phase of the grid voltage changes due to an increase in the grid frequency, power converter 1 reduces the power it outputs (discharges) to suppress the increase in grid frequency.

[0197] • When charging When the power converter 3 is charging, as explained in the embodiment described above, the relationship between the phase lead and phase lag between the grid voltage and the output voltage of the power converter 3 is reversed compared to when it is discharging.

[0198] In other words, in this embodiment, when the grid frequency decreases, the phase difference φ becomes smaller than the phase difference φ when the grid frequency is stable due to the action of the phase adjustment unit 52 described above, and the power input (charged) to the power converter 1 becomes smaller when the grid frequency decreases than when the grid frequency is stable. That is, when the phase of the grid voltage changes due to a decrease in the grid frequency, the power converter 1 reduces the power input (charged) to suppress the decrease in grid frequency.

[0199] Furthermore, in this embodiment, when the grid frequency increases, the phase difference φ becomes larger than the phase difference φ when the grid frequency is stable due to the action of the phase adjustment unit 52 described above, and the power input (charged) to the power converter 1 becomes larger when the grid frequency increases than when the grid frequency is stable. In other words, when the phase of the grid voltage changes due to an increase in the grid frequency, the power converter 1 increases the power input (charged) to suppress the increase in the grid frequency.

[0200] Next, an example of the operation of the power control device 2 according to the fifth embodiment will be described with reference to the flowchart in Figure 17.

[0201] In the power control device 2, the system voltage measurement unit 2a receives a voltage signal supplied from the instrument transformer VT and measures the AC waveform of the system voltage from this signal (step S1). This system voltage measurement unit 2a, for example, obtains and outputs a numerical value of the three-phase voltage waveform (sine wave) from the voltage signal supplied from the instrument transformer VT.

[0202] Next, the voltage phase calculation unit 51 determines the phase of the voltage measured by the system voltage measurement unit 2a (step S2D). This voltage phase calculation unit 51, for example, converts the three-phase voltage waveform of the voltage into a three-phase two-phase waveform, calculates the phase value, and outputs it.

[0203] Next, the phase adjustment unit 52 adjusts the phase of the voltage measured by the voltage phase calculation unit 51 (step S2E). The phase adjustment unit 52 calculates and outputs a value obtained by applying a first-order lag calculation of angular velocity to the phase adjustment (for example, a phase adjusted using a value obtained by multiplying the difference between the angular velocity value output by the phase measurement unit 51 and the first-order lag value of angular velocity by a coefficient as needed).

[0204] Next, the AC waveform generation unit 53 generates a three-phase AC waveform from the phase adjusted by the phase adjustment unit 52 (step S2F). This AC waveform generation unit 53, for example, calculates and outputs a three-phase AC waveform (for example, cos(θαlag), cos(θαlag-2·π / 3), cos(θαlag-4·π / 3)) from the phase (phase θαlag).

[0205] Next, the phase calculation unit 2b determines the phase from the three-phase AC waveform generated by the AC waveform generation unit 53 (step S2G). This phase calculation unit 2b, for example, converts the three-phase voltage waveform of a voltage into a three-phase two-phase waveform, calculates the phase value, and outputs it.

[0206] Next, the voltage command value calculation unit 2c determines a control command value for the power converter 1 based on the voltage phase determined by the phase calculation unit 2b (step S3). The voltage command value calculation unit 2c determines and outputs a voltage command value from, for example, the voltage phase determined by the phase calculation unit 2b and the d-axis current deviation and q-axis current deviation calculated by the calculation units 3c and 3f.

[0207] Next, the two-phase to three-phase conversion unit 2d generates an AC waveform of the control command value obtained by the voltage command value calculation unit 2c by converting the control command value between two phases and three phases (step S4). This two-phase to three-phase conversion unit 2d, for example, converts the voltage command value obtained by the voltage command value calculation unit 2c into a command value for a three-phase voltage waveform and outputs it (for example, it obtains and outputs values ​​obtained by converting the α-axis voltage command value and β-axis voltage command value into a three-phase AC voltage command value).

[0208] The command values ​​of the three-phase voltage waveforms generated by the two-phase to three-phase conversion unit 2d are sent to the U-phase signal generation unit 5A, the V-phase signal generation unit 5B, and the W-phase signal generation unit 5C, respectively, to generate signals for the U-phase, V-phase, and W-phase. These signals are then supplied to the power converter 1, and the input and output of the power converter 1 are controlled.

[0209] As a result, for example, when the power converter 3 is discharging, if the grid frequency decreases, the phase difference φ between the grid voltage and the output voltage of the power converter 1 increases, causing the power converter 1 to increase the power output (discharge) and suppress the decrease in grid frequency. On the other hand, if the grid frequency increases, the phase difference φ between the grid voltage and the output voltage of the power converter 1 decreases, causing the power converter 1 to decrease the power output (discharge) and suppress the increase in grid frequency.

[0210] Furthermore, when the power converter 3 is charging, if the grid frequency decreases, the phase difference φ between the grid voltage and the output voltage of the power converter 1 decreases, causing the power converter 1 to reduce the input (charging) power and suppress the decrease in grid frequency. On the other hand, if the grid frequency increases, the phase difference φ between the grid voltage and the output voltage of the power converter 1 increases, causing the power converter 1 to increase the input (charging) power and suppress the increase in grid frequency.

[0211] According to the fifth embodiment, when the phase of an electrical quantity such as the system voltage fluctuates due to frequency fluctuations in an AC electrical circuit such as a power system S, even if the input / output command value (active power control command value, etc.) of the power converter 3 remains constant, the phase adjustment unit 52 adjusts the phase of the voltage measured by the voltage phase calculation unit 51. This allows the difference between the phase of the electrical quantity (voltage, current, power, etc.) input / output to the power converter 3 and the phase of the electrical quantity (voltage, current, power, etc.) of the electrical circuit such as the power system S to be changed, thereby enabling the input / output of the power converter 1 to be changed.

[0212] This makes it possible to achieve operation similar to the inertial response in a synchronous machine (simulation of inertial response), thereby suppressing frequency fluctuations and oscillations in the electrical circuit and contributing to frequency stabilization of the electrical circuit.

[0213] [Embodiments 6-1, 6-2, 6-3, 6-4, and 6-5] Next, embodiments 6-1, 6-2, 6-3, 6-4, and 6-5 will be described. In the following, the explanation of parts common to embodiments 1 to 5 will be omitted, and the explanation will focus on the differences.

[0214] Figure 18A shows an example of the configuration of a charge / discharge equipment having a power converter according to the 6-1 embodiment. Note that in Figure 18A, the same reference numerals are used for elements common to Figure 2 shown in the first embodiment. Figure 18B shows an example of the configuration of a charge / discharge equipment having a power converter according to the 6-2 embodiment. Note that in Figure 18B, the same reference numerals are used for elements common to Figure 9 shown in the second embodiment. Figure 18C shows an example of the configuration of a charge / discharge equipment having a power converter according to the 6-3 embodiment. Note that in Figure 18C, the same reference numerals are used for elements common to Figure 12 shown in the third embodiment. Figure 18D shows an example of the configuration of a charge / discharge equipment having a power converter according to the 6-4 embodiment. Note that in Figure 18D, the same reference numerals are used for elements common to Figure 14 shown in the fourth embodiment. Figure 18E shows an example of the configuration of a charge / discharge equipment having a power converter according to the 6-5 embodiment. In Figure 18E, elements common to both Figure 16 and the fifth embodiment are denoted by the same reference numerals.

[0215] Figures 18A, 18B, 18C, 18D, and 18E each illustrate the situation when the system frequency decreases. The situations when the system frequency is stable and when the system frequency increases can be easily inferred from the descriptions of the embodiments described above, so their illustrations and explanations are omitted.

[0216] The power control device 2 according to the 6-1 embodiment, as shown in Figure 18A, further comprises a function switching command unit (function switching command means) 61 in addition to the components shown in the first embodiment (Figure 2, etc.). The power control device 2 according to the 6-2 embodiment, as shown in Figure 18B, further comprises a function switching command unit (function switching command means) 61 in addition to the components shown in the second embodiment (Figure 9, etc.). The power control device 2 according to the 6-3 embodiment, as shown in Figure 18C, further comprises a function switching command unit (function switching command means) 61 in addition to the components shown in the third embodiment (Figure 12, etc.). The power control device 2 according to the 6-4 embodiment, as shown in Figure 18D, further comprises a function switching command unit (function switching command means) 61 in addition to the components shown in the fourth embodiment (Figure 14, etc.). The power control device 2 according to the 6-5 embodiment, as shown in Figure 18E, further includes a function switching command unit (function switching command means) 61 in addition to the components shown in the 5th embodiment (Figure 16, etc.).

[0217] Furthermore, the phase adjustment units 11, 21, 32, and 41-43 shown in Figures 18A, 18B, 18C, 18D, and 18E, respectively, have multiple functions that allow the degree of phase adjustment (for example, the degree to which the phase is adjusted) to be changed.

[0218] The function switching command unit 61 shown in Figures 18A, 18B, 18C, 18D, and 18E respectively, has the function of specifying a function to be used for phase adjustment from among a plurality of functions provided in the corresponding phase adjustment unit, and issuing a function switching command (function switching command) to the phase adjustment unit so that the specified function is used for phase adjustment. This function switching command unit 61 may be configured to issue commands by manual operation, or it may be configured to issue commands in response to external commands.

[0219] Figure 18F is a diagram showing an example of the functional configuration of the phase adjustment unit provided in the power control device according to the embodiments of 6-1, 6-2, 6-3, 6-4, and 6-5. Here, the function of the phase adjustment unit 11 in the embodiment of 6-1 will be explained as an example. Note that the phase adjustment function of the phase adjustment units 21, 32, 41~43, and 52 in the embodiments of 6-2, 6-3, 6-4, and 6-5 is the same as that of the phase adjustment unit 11, so their explanation will be omitted. Note that the phase adjustment units 21, 32, 41~43, and 52 do not output the adjusted phase value, but rather the value of the input signal with the phase adjusted (the value of a waveform with the same amplitude as the input waveform but with adjusted phase).

[0220] As shown in Figure 18F, the phase adjustment unit 11 includes a first function calculation unit F1, a second function calculation unit F2, a limit value calculation unit L1, switches SWa, SWb, SWc, SWd, and a limit value priority calculation unit P1.

[0221] The first function unit F1 outputs the result (e.g., θ1lag) of adjusting the phase of the input signal using a first function applied to the input signal. This function includes, for example, a function to find the angular velocity value (ω) of the input signal (θ), a function to find the first first-order lag value of the input signal's angular velocity (ω1lag), a function to find the difference (ω1dif) between the first first-order lag value of the input signal's angular velocity and the input signal's angular velocity value, a function to multiply by a coefficient, and a function to convert the angular velocity value to a phase value by multiplying by time (Δt). The function to find the first-order lag value of the angular velocity includes a time constant T1, and the function to multiply by a coefficient includes a coefficient K1. The calculations performed by the first function unit F1 are, for example, as follows.

[0222] ω = θ / Δt (Δt: sampling period) ω1lag = ω / (1+T1·s) (s: Laplace operator) ω1dif=ω1lag-ω θ1lag = K2·ω1dif·Δt The second function operation unit F2 outputs the result (e.g., θ2lag) obtained by adjusting the phase of the input signal using the second function with respect to the input signal. This function includes, for example, a function for obtaining the value (ω) of the angular velocity of the input signal (θ), a function for obtaining the value (ω2lag) of the second-order first lag of the angular velocity of the input signal, a function for obtaining the difference (ω2dif) between the value of the second-order first lag of the angular velocity of the input signal and the value of the angular velocity of the input signal, a function for multiplying by a coefficient, and a function for multiplying by time (Δt) to convert the value of the angular velocity into the value of the phase. Further, the function for obtaining the value of the first lag of the angular velocity includes the time constant T1, and the function for multiplying by a coefficient includes the coefficient K1. The operations performed by the first function operation unit F1 are, for example, as follows.

[0223] ω = θ / Δt (Δt: sampling period) ω2lag = ω / (1 + T2·s) (s: Laplace operator) ω2dif = ω2lag - ω θ2lag = K2·ω2dif·Δt Note that in both the first function operation unit F1 and the second function operation unit F2, the multiplication by a coefficient and / or Δt is not necessarily required. When obtaining the adjusted phase value using the change amount of the phase (e.g., Δθ) instead of the angular velocity, the multiplication by Δt is unnecessary. Further, when using a dimensionless number such as a pu value for various numerical values, when the value of Δt is constant, or when including the value of Δt in the coefficient for multiplication, etc., the multiplication by a coefficient and / or Δt can be omitted.

[0224] The limit value operation unit L1 calculates and outputs the result obtained by restricting the adjusted value of the phase of the input signal by an upper limit value and / or a lower limit value.

[0225] The limit value priority operation unit P1 inputs the output signals of the first function operation unit F1 and the second function operation unit F2, and also inputs the output signal of the limit value operation unit L1, and preferentially outputs the signal whose value is within the limit value (e.g., the signal with the smaller absolute value).

[0226] For example, if T1 > T2 and K1 = K2, to increase the effect of inertial response simulation (transient frequency change suppression) in the power converter 3, you should close the switch (SWa) in the path of the function with a large time constant (F1) and open SWb. To decrease the effect of inertial response simulation, you should close the switch (SWb) in the path of the function with a small time constant (F2) and open SWa.

[0227] For example, if T1=T2 and K1>K2, to increase the effect of inertial response simulation (transient frequency change suppression) in the power converter 3, you should close the switch (SWa) in the path of the function with a large coefficient (F1) and open SWb. To decrease the effect of inertial response simulation, you should close the switch (SWb) in the path of the function with a small coefficient (F2) and open SWa.

[0228] If you want to perform the same control as the conventional power converter 3 without simulating the inertial response, you can close SWc and open SWa, SWb, and SWd. In this case, the output (phase) of the phase adjustment unit 11 will be the same as the input (phase) of the phase adjustment unit 11.

[0229] In the example above, we described the case where there are two types of functions, but there may be three or more types of functions, or even just one type. If there is only one type of function, the function path switch should be closed when performing inertial response simulation, and the function path switch should be opened when not performing inertial response simulation. Other calculations (functions) besides first-order lag calculations may be used for phase adjustment calculations. For example, second-order lag calculations or PLL (phase-locked loop) calculations may be used. The limit value calculation unit L1 and the limit value priority calculation unit P1 may be provided outside the phase adjustment unit 11, or multiple limit value calculation units may be provided so that the limit values ​​can be switched by switches, etc. The time constant and / or coefficient may be constants or variables (for example, values ​​obtained by a function).

[0230] Next, an example of the operation of the power control device 2 according to the 6-1 embodiment will be described with reference to the flowchart in Figure 19A. Here, the explanation of parts common to the flowchart in Figure 7A shown in the first embodiment will be omitted, and the differences will be explained.

[0231] The processes described in steps S1 and S2 above are also performed in this embodiment.

[0232] In the power control device 2, the function switching command unit 61 specifies a function to be used for phase adjustment from among the multiple functions provided in the phase adjustment unit 11, and gives a function switching command to the phase adjustment unit 11 so that the said function is used for phase adjustment (step S21).

[0233] Next, the phase adjustment unit 11 adjusts the phase of the voltage obtained by the phase calculation unit 2b using the specified function, in accordance with the command given by the function switching command unit 61 (step S3A-1).

[0234] After this, the same process as in steps S3B and S4 described above is performed.

[0235] According to the embodiment of 6-1, by giving a function switching command from the function switching command unit 61 to the phase adjustment unit 11, it becomes possible to specify or not specify a function to be used for phase adjustment from among the multiple functions provided in the phase adjustment unit 11, thereby adjusting the effect of inertial response simulation.

[0236] Next, an example of the operation of the power control device 2 according to the 6-2 embodiment will be described with reference to the flowchart in Figure 19B. Here, the explanation of parts common to the flowchart in Figure 11 shown in the second embodiment will be omitted, and the differences will be explained.

[0237] The processes described in steps S1 to S3 above are also performed in this embodiment.

[0238] In the power control device 2, the function switching command unit 61 specifies a function to be used for phase adjustment from among the multiple functions provided in the phase adjustment unit 21, and gives a function switching command to the phase adjustment unit 21 so that the said function is used for phase adjustment (step S21).

[0239] Next, the phase adjustment unit 21 adjusts the phase of the voltage command value obtained by the voltage command value calculation unit 2c using the specified function in accordance with the command given from the function switching command unit 61 (step S4A-1).

[0240] After this, the same processing as step S4B described above is performed.

[0241] According to the 6-2nd embodiment, by giving a function switching command from the function switching command unit 61 to the phase adjustment unit 21, it becomes possible to specify or not specify the function to be used for phase adjustment from among the plurality of functions provided in the phase adjustment unit 21. Therefore, the effect of the inertia response simulation can be adjusted.

[0242] Next, referring to the flowchart of FIG. 19C, an example of the operation of the power control device 2 according to the 6-3rd embodiment will be described. Here, the description of the common parts with the flowchart of FIG. 13 shown in the 3rd embodiment is omitted, and the different parts will be described.

[0243] The processing of steps S1 and S2A described above is also performed in this embodiment.

[0244] In the power control device 2, the function switching command unit 61 specifies the function to be used for phase adjustment from among the plurality of functions provided in the phase adjustment unit 32, and gives a function switching command to the phase adjustment unit 32 so that the function is used for phase adjustment (step S21).

[0245] Next, the phase adjustment unit 32 adjusts the phase of the voltage obtained by the three-phase to two-phase conversion unit 31 using the specified function in accordance with the command given from the function switching command unit 61 (step S2B-1).

[0246] After this, the same processing as steps S2C, S3, and S4 described above is performed.

[0247] According to the 6-3 embodiment, by giving a function switching command from the function switching command unit 61 to the phase adjustment unit 32, it becomes possible to specify or not specify a function to be used for phase adjustment from among the multiple functions provided in the phase adjustment unit 32, thereby adjusting the effect of inertial response simulation.

[0248] Next, an example of the operation of the power control device 2 according to the 6-4 embodiment will be described with reference to the flowchart in Figure 19D. Here, the explanation of parts common to the flowchart in Figure 15 shown in the 4th embodiment will be omitted, and the differences will be explained.

[0249] The processes described in steps S1 to S4 above are also performed in this embodiment.

[0250] In the power control device 2, the function switching command unit 61 specifies which function to be used for phase adjustment from among the multiple functions provided in each of the phase adjustment units 41 to 43, and gives a function switching command to each of the phase adjustment units 41 to 43 so that the specified function is used for phase adjustment (step S21).

[0251] Next, the phase adjustment units 41 to 43 each adjust the phase of the command value of the three-phase voltage waveform generated by the two-phase to three-phase conversion unit 2d using the specified function, in accordance with the command given by the function switching command unit 61 (step S5-1).

[0252] According to the 6-4 embodiment, by issuing function switching commands from the function switching command unit 61 to the phase adjustment units 41 to 43, it becomes possible to specify or not specify a function from among the multiple functions provided in the phase adjustment units 41 to 43, thereby adjusting the effect of the inertial response simulation.

[0253] Next, an example of the operation of the power control device 2 according to the 6-5 embodiment will be described with reference to the flowchart in Figure 19E. Here, the explanation of parts common to the flowchart in Figure 17 shown in the 5th embodiment will be omitted, and the differences will be explained.

[0254] The processes described in steps S1 and S2D above are also performed in this embodiment.

[0255] In the power control device 2, the function switching command unit 61 specifies a function to be used for phase adjustment from among the multiple functions provided in the phase adjustment unit 52, and gives a function switching command to the phase adjustment unit 52 so that the said function is used for phase adjustment (step S21).

[0256] Next, the phase adjustment unit 52 adjusts the phase of the voltage measured by the voltage phase calculation unit 51 using a specified function, in accordance with the command given by the function switching command unit 61 (step S2E-1).

[0257] After this, the same processes as those described in steps S2F, S2G, S3, and S4 are performed.

[0258] According to the 6-5 embodiment, by giving a function switching command from the function switching command unit 61 to the phase adjustment unit 52, it becomes possible to specify or not specify a function to be used for phase adjustment from among the multiple functions provided in the phase adjustment unit 52, thereby adjusting the effect of inertial response simulation.

[0259] [Embodiments 7-1, 7-2, 7-3, 7-4, and 7-5] Next, embodiments 7-1, 7-2, 7-3, 7-4, and 7-5 will be described. In the following, the explanation of parts common to embodiments 1 through 5 will be omitted, and the explanation will focus on the differences.

[0260] Figure 20A shows an example of the configuration of a charge / discharge equipment having a power converter according to the 7-1 embodiment. In Figure 20A, the same reference numerals are used for elements common to Figure 2 shown in the first embodiment. Figure 20B shows an example of the configuration of a charge / discharge equipment having a power converter according to the 7-2 embodiment. In Figure 20B, the same reference numerals are used for elements common to Figure 9 shown in the second embodiment. Figure 20C shows an example of the configuration of a charge / discharge equipment having a power converter according to the 7-3 embodiment. In Figure 20C, the same reference numerals are used for elements common to Figure 12 shown in the third embodiment. Figure 20D shows an example of the configuration of a charge / discharge equipment having a power converter according to the 7-4 embodiment. In Figure 20D, the same reference numerals are used for elements common to Figure 14 shown in the fourth embodiment. Figure 20E shows an example of the configuration of a charge / discharge equipment having a power converter according to the 7-5 embodiment. In Figure 2E, elements common to both Figure 16 and the fifth embodiment are denoted by the same reference numerals.

[0261] Figures 20A, 20B, 20C, 20D, and 20E each illustrate the situation when the system frequency decreases. The situations when the system frequency is stable and when the system frequency increases can be easily inferred from the descriptions of the embodiments described above, so their illustrations and explanations are omitted.

[0262] As shown in Figure 20A, the power control device 2 according to the 7-1 embodiment further comprises a coefficient change command unit (coefficient change command means) 71 in addition to the components shown in the first embodiment (Figure 2, etc.). As shown in Figure 20B, the power control device 2 according to the 7-2 embodiment further comprises a coefficient change command unit (coefficient change command means) 71 in addition to the components shown in the second embodiment (Figure 9, etc.). As shown in Figure 20C, the power control device 2 according to the 7-3 embodiment further comprises a coefficient change command unit (coefficient change command means) 71 in addition to the components shown in the third embodiment (Figure 12, etc.). As shown in Figure 20D, the power control device 2 according to the 7-4 embodiment further comprises a coefficient change command unit (coefficient change command means) 71 in addition to the components shown in the fourth embodiment (Figure 14, etc.). As shown in Figure 20E, the power control device 2 according to the 7-5 embodiment further comprises a coefficient change command unit (coefficient change command means) 71 in addition to the components shown in the fifth embodiment (Figure 16, etc.).

[0263] Furthermore, the phase adjustment units 11, 21, 32, 41-43, and 52 shown in Figures 20A, 20B, 20C, 20D, and 20E, respectively, have a function that allows the degree of phase adjustment (for example, the degree to which the phase is adjusted) to be changed according to the value of a coefficient.

[0264] The coefficient change command units 71 shown in Figures 20A, 20B, 20C, 20D, and 20E respectively have the function of issuing a command to the corresponding phase adjustment unit to change the time constant and / or coefficient (coefficient change command) so that the values ​​of the time constant and / or coefficient to be applied in the function used for adjusting the phase within the corresponding phase adjustment unit are used. The coefficient change command unit 71 may also be given the values ​​of the time constant and / or coefficient instead of issuing a command to change the time constant and / or coefficient. Furthermore, it may be configured to issue commands by manual operation or to issue commands in response to external commands.

[0265] Figure 20F is a diagram showing an example of the functional configuration of the phase adjustment unit provided in the power control device according to the embodiments of 7-1, 7-2, 7-3, 7-4, and 7-5. Here, the function of the phase adjustment unit 11 in the embodiment of 7-1 will be explained as an example. Note that the function of the phase adjustment units 21, 32, 41-43, and 52 in the embodiments of 7-2, 7-3, 7-4, and 7-5 to determine the adjusted phase (adjusting the phase using a value obtained by multiplying the first-order lag of the angular velocity and the difference in angular velocity by a coefficient as needed) is the same as that of the phase adjustment unit 11, so its explanation will be omitted. Note that the phase adjustment units 21, 32, 41-43, and 52 do not output the adjusted phase value, but rather output a value with the phase of the input signal adjusted (a value of a waveform with the same amplitude as the input waveform but with adjusted phase).

[0266] As shown in Figure 20F, the phase adjustment unit 11 includes a function calculation unit F20, a limit value calculation unit L1, and a limit value priority calculation unit P1.

[0267] The function calculation unit F20 outputs the result of adjusting the phase of the input signal using a function. This function includes, for example, a function to find the angular velocity value (ω) of the input signal (θ), a function to find the first-order lag value (ωlag) of the input signal's angular velocity, a function to find the difference (ωdif) between the first-order lag value and the input signal's angular velocity value, a function to multiply by a coefficient, and a function to convert the angular velocity value to a phase value by multiplying by time (Δt). The function to find the first-order lag value includes a time constant T, and the function to multiply by a coefficient includes a coefficient K. The first-order lag time constant T and / or the coefficient K in the coefficient multiplication unit can be changed. The calculations performed by the function calculation unit F20 are, for example, as follows.

[0268] ω = θ / Δt (Δt: sampling period) ωlag = ω / (1+T·s) (s: Laplace operator) ωdif=ωlag-ω θlag = K·ωdif·Δt The limit value calculation unit L1 calculates and outputs the result of limiting the phase adjustment value of the input signal by an upper limit and / or lower limit.

[0269] The limit value priority calculation unit P1 receives the output signal from the function calculation unit F20 as well as the output signal from the limit value calculation unit L1, and prioritizes outputting the signal whose value is within the limit range (for example, the signal with the smaller absolute value).

[0270] The time constant T of the first-order lag calculation included in the function of the function calculation unit F20 and / or the coefficient K of the coefficient calculation unit are changed by values ​​provided by the coefficient change command unit 71 or by coefficient change commands.

[0271] For example, to increase the effect of inertial response simulation (transient frequency change suppression) in the power converter 3, the time constant T and / or coefficient K should be increased. To decrease the effect of inertial response simulation, the time constant T and / or coefficient K should be decreased. To perform control similar to that of the conventional power converter 3 without simulating the inertial response, the coefficient K should be set to 0. When the coefficient K is set to 0, the output of the phase adjustment unit 11 becomes the same as the input of the phase adjustment unit 11.

[0272] Note that calculations other than first-order lag calculations (functions) may be used for phase adjustment. For example, PLL (phase-locked loop) calculations or second-order lag calculations may be used, and one or more time constants and / or coefficients within the PLL calculation or second-order lag calculation may be changed. The limit value calculation unit L1 and the limit value priority calculation unit P1 may be provided outside the phase adjustment unit 11, or multiple limit value calculation units may be provided so that the limit values ​​can be switched by a switch or the like. There may be two types of time constants and / or coefficients, or three or more types.

[0273] Next, an example of the operation of the power control device 2 according to the 7-1 embodiment will be described with reference to the flowchart in Figure 21A. Here, the explanation of parts common to the flowchart in Figure 7A shown in the first embodiment will be omitted, and the differences will be explained.

[0274] The processes described in steps S1 and S2 above are also performed in this embodiment.

[0275] In the power control device 2, the coefficient change command unit 71 specifies the value of the coefficient to be applied to the function used for phase adjustment, and gives a coefficient change command to the phase adjustment unit 11 so that the value of the coefficient is applied to the above function (step S31).

[0276] Next, the phase adjustment unit 11 adjusts the phase of the voltage obtained by the phase calculation unit 2b using a function to which the specified time constant and / or coefficient are applied, in accordance with the command given by the coefficient change command unit 71 (step S3A-2).

[0277] After this, the same process as in steps S3B and S4 described above is performed.

[0278] According to the embodiment of 7-1, by giving a coefficient change command from the coefficient change command unit 71 to the phase adjustment unit 11, it becomes possible to change the value of the coefficient to be applied to the function provided in the phase adjustment unit 11, thereby allowing the effect of inertial response simulation to be adjusted.

[0279] Next, an example of the operation of the power control device 2 according to the 7-2 embodiment will be described with reference to the flowchart in Figure 21B. Here, the explanation of parts common to the flowchart in Figure 11 shown in the second embodiment will be omitted, and the differences will be explained.

[0280] The processes described in steps S1 to S3 above are also performed in this embodiment.

[0281] In the power control device 2, the coefficient change command unit 71 specifies the value of the coefficient to be applied to the function used for phase adjustment, and gives a coefficient change command to the phase adjustment unit 11 so that the value of the coefficient is applied to the above function (step S31).

[0282] Next, the phase adjustment unit 21 adjusts the phase of the voltage command value obtained by the voltage command value calculation unit 2c using a function to which the specified time constant and / or coefficient are applied, in accordance with the command given by the coefficient change command unit 71 (step S4A-2).

[0283] After this, the same process as in step S4B described above is performed.

[0284] According to the embodiment of 7-2, by giving a coefficient change command from the coefficient change command unit 71 to the phase adjustment unit 21, it becomes possible to change the value of the coefficient to be applied to the function provided in the phase adjustment unit 21, thereby allowing the effect of inertial response simulation to be adjusted.

[0285] Next, an example of the operation of the power control device 2 according to the 7-3 embodiment will be described with reference to the flowchart in Figure 21C. Here, the explanation of parts common to the flowchart in Figure 13 shown in the 3rd embodiment will be omitted, and the differences will be explained.

[0286] The processes described in steps S1 and S2A above are also performed in this embodiment.

[0287] In the power control device 2, the coefficient change command unit 71 specifies the value of the coefficient to be applied to the function used for phase adjustment, and gives a coefficient change command to the phase adjustment unit 32 so that the value of the coefficient is applied to the above function (step S31).

[0288] Next, the phase adjustment unit 32 adjusts the phase of the voltage obtained by the three-phase to two-phase conversion unit 31 using a function to which the specified time constant and / or coefficient are applied, in accordance with the command given by the coefficient change command unit 71 (step S2B-1).

[0289] After this, the same processes as those described in steps S2C, S3, and S4 are performed.

[0290] According to the seventh-third embodiment, by issuing a coefficient change command from the coefficient change command unit 71 to the phase adjustment unit 32, it becomes possible to change the value of the coefficient to be applied to the function provided in the phase adjustment unit 32, thereby allowing the effect of inertial response simulation to be adjusted.

[0291] Next, an example of the operation of the power control device 2 according to the 7-4 embodiment will be described with reference to the flowchart in Figure 21D. Here, the explanation of parts common to the flowchart in Figure 15 shown in the 4th embodiment will be omitted, and the differences will be explained.

[0292] The processes described in steps S1 to S4 above are also performed in this embodiment.

[0293] In the power control device 2, the coefficient change command unit 71 specifies the value of the coefficient to be applied to the function used for phase adjustment, and issues a coefficient change command to each of the phase adjustment units 41 to 43 so that the value of the coefficient is applied to the above function (step S31).

[0294] Next, the phase adjustment units 41 to 43 each adjust the phase of the command value of the three-phase voltage waveform generated by the two-phase to three-phase conversion unit 2d using a function to which the specified time constant and / or coefficient are applied, in accordance with the command given by the coefficient change command unit 71 (step S5-2).

[0295] According to the 7-4 embodiment, by issuing coefficient change commands from the coefficient change command unit 71 to the phase adjustment units 41 to 43, respectively, it becomes possible to change the values ​​of the coefficients to be applied to the functions provided in the phase adjustment units 41 to 43, respectively, thereby allowing the effect of inertial response simulation to be adjusted.

[0296] Next, an example of the operation of the power control device 2 according to the 7-5 embodiment will be described with reference to the flowchart in Figure 21E. Here, the explanation of parts common to the flowchart in Figure 17 shown in the 5th embodiment will be omitted, and the differences will be explained.

[0297] The processes described in steps S1 and S2D above are also performed in this embodiment.

[0298] In the power control device 2, the coefficient change command unit 71 specifies the value of the coefficient to be applied to the function used for phase adjustment, and gives a coefficient change command to the phase adjustment unit 52 so that the value of the coefficient is applied to the above function (step S31).

[0299] Next, the phase adjustment unit 52 adjusts the phase of the voltage measured by the voltage phase calculation unit 51 using a function to which the specified time constant and / or coefficient are applied, in accordance with the command given by the coefficient change command unit 71 (step S2E-2).

[0300] After this, the same processes as those described in steps S2F, S2G, S3, and S4 are performed.

[0301] According to the seventh-fifth embodiment, by giving a coefficient change command from the coefficient change command unit 71 to the phase adjustment unit 52, it becomes possible to change the value of the coefficient to be applied to the function provided in the phase adjustment unit 52, thereby allowing the effect of inertial response simulation to be adjusted.

[0302] [Eighth Embodiment] Next, we will describe the eighth embodiment. In the following, we will omit the explanation of parts that are common with the first to fifth embodiments and focus on the differences.

[0303] Figure 22A shows an example of the configuration of a charge / discharge equipment having a power conversion device according to the eighth embodiment. In Figure 22A, the same reference numerals are used for elements common to Figures 1-3, 8-11, 12, 14, and 16 shown in the first to fifth embodiments. The signals from the phase calculation unit 2b to the phase adjustment units 21, 41-43 are not shown.

[0304] The power control device 2 according to the eighth embodiment includes components from at least one of the following embodiments: the phase adjustment unit 11 shown in the first embodiment (Figure 1, etc.), the phase adjustment unit 21 shown in the second embodiment (Figure 8, etc.), the three-phase to two-phase conversion unit 31 and phase adjustment unit 32 shown in the third embodiment (Figure 12, etc.), the phase adjustment units 41 to 43 shown in the fourth embodiment (Figure 14, etc.), and the voltage phase calculation unit 51, phase adjustment unit 52, and AC waveform generation unit 53 shown in the fifth embodiment (Figure 16, etc.). For convenience, configuration examples of the above five embodiments are shown in the same drawing, but in order to obtain the effect of simulating inertial response, a configuration including only components from one type of embodiment is sufficient.

[0305] In Figure 22A, the phase adjustment unit 11 is further provided with switching units (switching means) SW1a and SW1b. These switching units enable switching between a first path that passes through the phase adjustment unit 11 and a second path (bypass BP1) that bypasses the phase adjustment unit 11.

[0306] When the switching unit SW1a is in the closed state and the switching unit SW1b is in the open state, a circuit is formed that supplies the output signal of the phase calculation unit 2b to the voltage command value calculation unit 2c after processing it in the phase adjustment unit 11 via the first path. Also, when the switching unit SW1b is in the closed state and the switching unit SW1a is in the open state, a circuit is formed that supplies the output signal of the phase calculation unit 2b to the voltage command value calculation unit 2c via the second path (bypass BP1) without passing through the phase adjustment unit 11.

[0307] In Figure 22A, the phase adjustment unit 21 is further provided with switching units (switching means) SW2a and SW2b. These switching units enable switching between a first path that passes through the phase adjustment unit 21 and a second path (bypass BP2) that bypasses the phase adjustment unit 21.

[0308] When the switching unit SW2a is in the closed state and the switching unit SW2b is in the open state, a circuit is formed that supplies the output signal of the voltage command value calculation unit 2c to the two-phase three-phase conversion unit 2d after processing it in the phase adjustment unit 21 via the first path. Also, when the switching unit SW2b is in the closed state and the switching unit SW2a is in the open state, a circuit is formed that supplies the output signal of the voltage command value calculation unit 2c to the two-phase three-phase conversion unit 2d via the second path (bypass BP2) without passing through the phase adjustment unit 21.

[0309] In Figure 22A, the phase adjustment unit 32 is further provided with switching units (switching means) SW3a and SW3b. These switching units enable switching between a first path that passes through the phase adjustment unit 32 and a second path (bypass BP3) that bypasses the phase adjustment unit 32 for the output signal of the three-phase two-phase conversion unit 31.

[0310] When the switching unit SW3a is in the closed state and the switching unit SW3b is in the open state, a circuit is formed that supplies the output signal of the three-phase to two-phase conversion unit 31 to the phase calculation unit 2b after processing it in the phase adjustment unit 32 via the first path. When the switching unit SW3b is in the closed state and the switching unit SW3a is in the open state, a circuit is formed that supplies the output signal of the three-phase to two-phase conversion unit 31 to the phase calculation unit 2b via the second path (bypass BP3) without passing through the phase adjustment unit 32.

[0311] In Figure 22A, the phase adjustment units 41 to 43 are further provided with switching units (switching means) SW4ua and SW4ub, SW4va and SW4vb, and SW4wa and SW4wb, respectively. These switching units enable switching between a first path that passes through the phase adjustment units 41 to 43 for the output signal of the two-phase to three-phase conversion unit 2d, and a second path (bypass BP4u, BP4v, BP4w) that bypasses the phase adjustment units 41 to 43.

[0312] When the switching units SW4ua, SW4va, and SW4wa are in the closed state and the switching units SW4ub, SW4vb, and SW4wb are in the open state, a circuit is formed that supplies the output signal of the two-phase three-phase conversion unit 2d to the U-phase signal generation unit 5A, V-phase signal generation unit 5B, and W-phase signal generation unit 5C after being processed by the phase adjustment units 41-43 via the first path. Also, when the switching units SW4ub, SW4vb, and SW4wb are in the closed state and the switching units SW4ua, SW4va, and SW4wa are in the open state, a circuit is formed that supplies the output signal of the two-phase three-phase conversion unit 2d to the U-phase signal generation unit 5A, V-phase signal generation unit 5B, and W-phase signal generation unit 5C via the second path (bypass BP4u, BP4v, BP4w) without passing through the phase adjustment units 41-43.

[0313] Switching units (switching means) SW5a and SW5b are further provided for the voltage phase calculation unit 51, phase adjustment unit 52, and AC waveform generation unit 53 in Figure 22A. These switching units enable switching between a first path that passes the output signal of the system voltage measurement unit 2a through the voltage phase calculation unit 51, phase adjustment unit 52, and AC waveform generation unit 53, and a second path (bypass BP5) that bypasses the voltage phase calculation unit 51, phase adjustment unit 52, and AC waveform generation unit 53.

[0314] When the switching unit SW5a is in the closed state and the switching unit SW5b is in the open state, a circuit is formed that supplies the output signal of the system voltage measurement unit 2a to the three-phase to two-phase conversion unit 31 after processing it through the voltage phase calculation unit 51, the phase adjustment unit 52, and the AC waveform generation unit 53 via a first path. When the switching unit SW5b is in the closed state and the switching unit SW5a is in the open state, a circuit is formed that supplies the output signal of the system voltage measurement unit 2a to the three-phase to two-phase conversion unit 31 via a second path (bypass BP5) without passing through the voltage phase calculation unit 51, the phase adjustment unit 52, and the AC waveform generation unit 53.

[0315] The power control device 2 according to this eighth embodiment further comprises a circuit switching command unit (circuit switching command means) 81. Each of the above-described switching units activates a designated route from among the first route and the second route in response to a route switching command given by the circuit switching command unit 81.

[0316] For example, the circuit switching command unit 81 has the function of specifying which path should be enabled from among the first path and the second path (bypass BP1) passing through the phase adjustment unit 11, and issuing switching commands (circuit switching commands) to the switching units SW1a and SW1b, respectively, to switch their open / closed states so that only that path is enabled.

[0317] Alternatively, the circuit switching command unit 81 has the function of specifying which path to enable from the first path and the second path (bypass BP2) passing through the phase adjustment unit 21, and issuing switching commands (circuit switching commands) to the switching units SW2a and SW2b, respectively, to switch their open / closed states so that only that path is enabled.

[0318] Alternatively, the circuit switching command unit 81 has the function of specifying which path to enable from the first path and the second path (bypass BP3) passing through the phase adjustment unit 32, and issuing switching commands (circuit switching commands) to the switching units SW3a and SW3b, respectively, so that only that path is enabled.

[0319] Alternatively, the circuit switching command unit 81 has the function of specifying which path to enable from among the first and second paths (bypass BP4u, BP4v, BP4w) passing through the phase adjustment units 41 to 43, and issuing switching commands (circuit switching commands) to the switching units SW4ua, SW4va, SW4wa, SW4ub, SW4vb, and SW4wb to enable only that path.

[0320] Alternatively, the circuit switching command unit 81 has the function of specifying which path to enable from among the first path and the second path (bypass BP5) passing through the voltage phase calculation unit 51, the phase adjustment unit 52, and the AC waveform generation unit 53, and giving switching commands (circuit switching commands) to the switching units SW5a and SW5b, respectively, so that only that path is enabled.

[0321] The circuit switching command unit 81 may be configured to issue commands by manual operation, or it may be configured to issue commands in response to external commands.

[0322] Figure 22B is a diagram showing an example of the functional configuration of each phase adjustment unit provided in the power control device 2 according to the eighth embodiment. Here, the function of the phase adjustment unit 11 will be explained as an example. Note that the function of phase adjustment units 21, 32, 41-43, and 52 to determine the adjusted phase is the same as that of phase adjustment unit 11, so its explanation will be omitted. Note that phase adjustment units 21, 32, 41-43, and 52 do not output the adjusted phase value, but rather output a value with the phase of the input signal adjusted (a value of a waveform with the same amplitude as the input waveform but with adjusted phase).

[0323] As shown in Figure 22B, the phase adjustment unit 11 includes a function calculation unit F22, a limit value calculation unit L1, and a limit value priority calculation unit P1.

[0324] The function arithmetic unit F22 outputs the result (e.g., θlag) of adjusting the phase of the input signal using a function. This function includes, for example, a function to find the angular velocity value (ω) of the input signal (θ), a function to find the first-order lag value of the input signal's angular velocity (ωlag), a function to find the difference (ωdif) between the first-order lag value of the input signal's angular velocity and the input signal's angular velocity value, a function to multiply by a coefficient, and a function to convert the angular velocity value to a phase value by multiplying by time (Δt). The function to find the first-order lag value of the angular velocity includes a time constant T, and the function to multiply by a coefficient includes a coefficient K. The calculations performed by the function arithmetic unit F22 are as follows, for example.

[0325] ω = θ / Δt (Δt: sampling period) ωlag = ω / (1+T·s) (s: Laplace operator) ωdif=ωlag-ω θlag = K·ωdif·Δt The limit value calculation unit L1 calculates and outputs the result of limiting the phase adjustment value of the input signal by an upper limit and / or lower limit.

[0326] The limit value priority calculation unit P1 receives the output signal from the function calculation unit F22 as well as the output signal from the limit value calculation unit L1, and prioritizes outputting the signal whose value is within the limit range (for example, the signal with the smaller absolute value).

[0327] Furthermore, calculations (functions) other than first-order lag calculations may be used for phase adjustment. For example, PLL (phase-locked loop) calculations or second-order lag calculations may be used. The limit value calculation unit L1 and the limit value priority calculation unit P1 may be provided outside the phase adjustment unit 11, or multiple limit value calculation units may be provided so that the limit values ​​can be switched using switches or the like.

[0328] Next, with reference to the flowchart in Figure 23A, an example (part 1) of the operation of the power control device 2 according to the eighth embodiment will be described. Here, the explanation of parts common to the flowchart in Figure 7A shown in the first embodiment will be omitted, and the differences will be explained.

[0329] The processes described in steps S1 and S2 above are also performed in this embodiment.

[0330] In the power control device 2, the circuit switching command unit 81 specifies which of the first and second paths (bypass BP1) passing through the phase adjustment unit 11 should be enabled, and issues a circuit switching command to the switching units SW1a and SW1b so that only that path is enabled. As a result, the switching units SW1a and SW1b switch their open / closed states according to the command given by the circuit switching command unit 81 so that the specified path is enabled. If the first path is enabled (NO in step S41), the phase adjustment unit 11 adjusts the phase of the voltage determined by the phase calculation unit 2b (steps S3A-3). If the second path (bypass BP1) is enabled (YES in step S41), no phase adjustment is performed.

[0331] Next, the voltage command value calculation unit 2c determines a control command value for the power converter 1 based on the phase adjusted by the phase adjustment unit 11 or the bypassed phase (step S3B-3). The voltage command value calculation unit 2c determines and outputs a voltage command value from, for example, the phase adjusted by the phase adjustment unit 11 or the bypassed phase, and the d-axis current deviation and q-axis current deviation calculated by the calculation units 3c and 3f.

[0332] After this, the same process as in step S4 described above is performed.

[0333] Next, with reference to the flowchart in Figure 23B, an example (part 2) of the operation of the power control device 2 according to the eighth embodiment will be described. Here, the explanation of the parts that are common with the flowchart in Figure 11 shown in the second embodiment will be omitted, and the differences will be explained.

[0334] The processes described in steps S1 to S3 above are also performed in this embodiment.

[0335] In the power control device 2, the circuit switching command unit 81 specifies which of the first and second paths (bypass BP2) passing through the phase adjustment unit 21 should be enabled, and issues a circuit switching command to the switching units SW2a and SW2b so that only that path is enabled. As a result, the switching units SW2a and SW2b switch their open / closed states according to the command given by the circuit switching command unit 81 so that the specified path is enabled. If the first path is enabled (NO in step S41), the phase adjustment unit 21 adjusts the phase of the voltage command value obtained by the voltage command value calculation unit 2c (step S4A-3). If the second path (bypass BP2) is enabled (YES in step S41), no phase adjustment is performed.

[0336] Subsequently, the two-phase to three-phase conversion unit 2d generates the AC waveform of the control command value by converting the voltage command value whose phase has been adjusted by the phase adjustment unit 21 or the bypassed voltage command value between two phases and three phases (step S4B-3). The two-phase to three-phase conversion unit 2d, for example, converts the voltage command value whose phase has been adjusted by the phase adjustment unit 21 into a command value for a three-phase voltage waveform and outputs it (for example, it obtains and outputs values ​​obtained by converting the α-axis voltage command value and the β-axis voltage command value into three-phase AC voltage command values).

[0337] Next, with reference to the flowchart in Figure 23C, an example (part 3) of the operation of the power control device 2 according to the eighth embodiment will be described. Here, the explanation of the parts that are common with the flowchart in Figure 13 shown in the third embodiment will be omitted, and the differences will be explained.

[0338] The processes described in steps S1 and S2A above are also performed in this embodiment.

[0339] In the power control device 2, the circuit switching command unit 81 specifies which of the first and second paths (bypass BP3) passing through the phase adjustment unit 32 should be enabled, and issues a circuit switching command to the switching units SW3a and SW3b so that only that path is enabled. As a result, the switching units SW3a and SW3b switch their open / closed states according to the command given by the circuit switching command unit 81 so that the specified path is enabled. If the first path is enabled (NO in step S41), the phase adjustment unit 32 adjusts the phase of the voltage determined by the three-phase to two-phase conversion unit 31 (step S2B-3). If the second path (bypass BP3) is enabled (YES in step S41), no phase adjustment is performed.

[0340] Next, the phase calculation unit 2b determines the phase of a voltage from the voltage whose phase has been adjusted by the phase adjustment unit 32 or from the bypassed voltage (step S2C-3). This phase calculation unit 2b, for example, determines and outputs the phase value from the phase-adjusted α-axis voltage and β-axis voltage.

[0341] After this, the same process as in steps S3 and S4 described above is performed.

[0342] Next, referring to the flowchart in Figure 23D, an example (part 4) of the operation of the power control device 2 according to the eighth embodiment will be described. Here, the explanation of the parts that are common with the flowchart in Figure 15 shown in the fourth embodiment will be omitted, and the differences will be explained.

[0343] The processes described in steps S1 to S4 above are also performed in this embodiment.

[0344] In the power control device 2, the circuit switching command unit 81 specifies which path to enable from the first path and the second path (bypass BP4u, BP4v, BP4w) passing through the phase adjustment units 41 to 43, and issues circuit switching commands to the switching units SW4ua, SW4va, SW4wa, SW4ub, SW4vb, SW4wb so that only the specified path is enabled. As a result, the switching units SW4ua, SW4va, SW4wa, SW4ub, SW4vb, SW4wb switch their open / closed states according to the commands given by the circuit switching command unit 81 so that the specified path is enabled. If the first path is enabled (NO in step S41), the phase adjustment units 41 to 43 determine the value obtained by adjusting the phase of the command value of the three-phase voltage waveform generated by the two-phase to three-phase conversion unit 2d (step S5B-3). If the second path (bypass BP4u, BP4v, BP4w) is enabled, no phase adjustment is performed (YES in step S41).

[0345] Next, with reference to the flowchart in Figure 23E, an example (part 5) of the operation of the power control device 2 according to the eighth embodiment will be described. Here, the explanation of the parts that are common with the flowchart in Figure 17 shown in the fifth embodiment will be omitted, and the differences will be explained.

[0346] The process of step S1 described above is also performed in this embodiment.

[0347] In the power control device 2, the circuit switching command unit 81 specifies which of the first and second paths (bypass BP5) passing through the voltage phase calculation unit 51, the phase adjustment unit 52, and the AC waveform generation unit 53 should be enabled, and issues a circuit switching command to the switching units SW5a and SW5b so that only the specified path is enabled. As a result, the switching units SW5a and SW5b switch their open / closed states according to the command given by the circuit switching command unit 81 so that the specified path is enabled. If the first path is enabled (NO in step S41), the voltage phase calculation unit 51 determines the phase of the voltage measured by the system voltage measurement unit 2a (step S2D-3), the phase adjustment unit 52 adjusts the phase of the voltage measured by the voltage phase calculation unit 51 (step S2E), and the AC waveform generation unit 53 generates a three-phase AC waveform of the voltage whose phase has been adjusted by the phase adjustment unit 52 (step S2F). If the second path (bypass BP5) is enabled, the voltage phase calculation unit 51, the phase adjustment unit 52, and the AC waveform generation unit 53 do not perform any processing (YES in step S41).

[0348] Next, the phase calculation unit 2b determines the phase from the three-phase AC waveform (phase-adjusted three-phase AC waveform) or bypassed three-phase AC waveform generated by the AC waveform generation unit 53 (step S2G-3). This phase calculation unit 2b, for example, converts a three-phase voltage waveform of a voltage into a three-phase two-phase waveform, determines the phase value, and outputs it.

[0349] After this, the same process as in steps S3 and S4 described above is performed.

[0350] According to the eighth embodiment, by issuing a circuit switching command from the circuit switching command unit 81 to any switching unit, it becomes possible to switch the paths so that only one of the first and second paths becomes active, thereby enabling / disabling the inertial response simulation.

[0351] Furthermore, if the functions related to route switching are implemented in software, the circuits that constitute the switching units SW1 and SW2, the first route, the second route, etc., can be omitted.

[0352] [Embodiments of 9-1, 9-2, and 9-3] Next, embodiments 9-1, 9-2, and 9-3 will be described. In the following, the descriptions of parts common to embodiments 6-1, 6-2, 6-3, 6-4, and 6-5, embodiments 7-1, 7-2, 7-3, 7-4, and 7-5, and embodiment 8 will be omitted, and the descriptions will focus on the differences.

[0353] Figure 24A shows an example of the configuration of a charging and discharging equipment having a power converter according to the embodiment of 9-1. Figure 24B shows an example of the configuration of a charging and discharging equipment having a power converter according to the embodiment of 9-2. Figure 24C shows an example of the configuration of a charging and discharging equipment having a power converter according to the embodiment of 9-3.

[0354] The power conversion device 3 according to the embodiment of 9-1 includes an electrical quantity change processing unit 10 and a power control device 2, as shown in Figure 24A. This power control device 2 corresponds to the power control device 2 shown in embodiments 6-1, 6-2, 6-3, 6-4, and 6-5 (Figures 18A, 18B, 18C, 18D, 18E, etc.). However, in this embodiment, instead of providing a function switching command unit 61 inside the power control device 2, a function switching command unit 96-1 having the same function as the function switching command unit 61 is provided outside the power control device 2.

[0355] The electrical quantity change processing unit 10 includes a reference value setting unit 90, a current measurement unit 91, a system voltage measurement unit 92, a phase calculation unit 93, an electrical quantity change calculation unit (electrical quantity change calculation means) 94, a comparison unit (comparison means) 95, and a function switching command unit (command means) 96-1.

[0356] The reference value setting unit 90 has a function to set a reference value for the amount or rate of change of an electrical quantity (voltage, current, power, phase, etc.) and a function to output the set reference value. The reference value referred to here is at least one of three types of reference values, which are, for example, a reference value used for comparison with the amount or rate of change of current measured by the current measurement unit 91, a reference value used for comparison with the amount or rate of change of voltage measured by the system voltage measurement unit 92, and a reference value used for comparison with the amount or rate of change of phase determined by the phase calculation unit 93. Here, an example is shown in which the unit has a function to set all three types of reference values ​​and a function to output the set reference value, but it is not limited to this example. There may be only two types or only one type of reference value. Here, an example is shown in which there is a current measurement unit 91, a system voltage measurement unit 92, and a phase calculation unit 93, but the phase calculation unit 93 may be omitted, or only one of the current measurement unit 91 or the system voltage measurement unit 92 may be included.

[0357] The current measuring unit 91 receives the current signal supplied from the current transformer CT1 and measures the AC waveform of the current (electric current) flowing through the electrical circuit on the output side of the power converter 1 from this signal.

[0358] The system voltage measurement unit 92 receives a voltage signal supplied from the instrument transformer VT and measures the AC waveform of the system voltage from this signal. This system voltage measurement unit 2a, for example, calculates and outputs a numerical value of the three-phase voltage waveform (sine wave) from the voltage signal supplied from the instrument transformer VT.

[0359] The phase calculation unit 93 determines the phase of the AC waveform of the voltage measured by the system voltage measurement unit 92. This phase calculation unit 93, for example, converts the three-phase voltage waveform of the voltage to a three-phase to two-phase converter, calculates the phase value, and outputs it.

[0360] The electrical quantity change calculation unit 94 determines the amount of change or rate of change of electrical quantities (current, voltage, phase, etc.) obtained by the current measurement unit 91, the system voltage measurement unit 92, or the phase calculation unit 93. Here, "amount of change" refers to a broad range of changes, including the rate of change.

[0361] The electrical quantity change calculation unit 94 receives input from the current value measured by the current measurement unit 91, the voltage value measured by the system voltage measurement unit 92, or the phase value obtained by the phase calculation unit 93.

[0362] The comparison unit 95 outputs information indicating whether the amount or rate of change of the electrical quantity determined by the electrical quantity change calculation unit 94 is equal to or greater than (or less than or equal to) a predetermined reference value set by the reference value setting unit 90.

[0363] The comparison unit 95 receives, for example, the value of the amount or rate of change of an electrical quantity (current, voltage, phase, etc.) obtained by the electrical quantity change calculation unit 94, and also receives a reference value corresponding to the amount or rate of change of the electrical quantity from the reference value setting unit 90. The comparison unit then performs a comparison of the two and outputs information indicating whether the value of the amount or rate of change of the electrical quantity is greater than or greater than the reference value (or less than or equal to a predetermined reference value). If the value of the amount or rate of change of the electrical quantity is greater than or greater than the reference value (or less than or equal to a predetermined reference value), it outputs a value such as "1" as information indicating that the conditions for performing inertial response simulation are met, and if not, it outputs a value such as "0".

[0364] The function switching command unit 96-1, in accordance with the information output from the comparison unit 95, specifies which function to be used for phase adjustment from among the multiple functions provided in the corresponding phase adjustment unit (any of the phase adjustment units 11, 21, 32, 41-43, 52) in the power control device 2, and gives a command (function switching command) to the corresponding phase adjustment unit in the power control device 2 to switch the function (switch on / off) so that the said function is used for phase adjustment.

[0365] If the information output from the comparison unit 95 does not indicate that the conditions for performing inertial response simulation are met (for example, if the value is "0"), the function switching command unit 96-1 gives a function switching command (switch on / off command) to the corresponding phase adjustment unit in the power control device 2 so that the calculation process by the function is bypassed and inertial response simulation is not performed. On the other hand, if the information output from the comparison unit 95 indicates that the conditions for performing inertial response simulation are met (for example, if the value is "1"), the function switching command unit 96-1 gives a function switching command (switch on / off command) to the corresponding phase adjustment unit in the power control device 2 so that a predetermined function is used for phase adjustment so that inertial response simulation is performed.

[0366] For example, if a grid fault occurs and the change in grid voltage exceeds a reference value, the function switching command unit 96-1 issues a function switching command (switch on / off command) to the corresponding phase adjustment unit in the power control device 2 so that a function to adjust the phase is used (or a function to increase the degree of phase adjustment is used). Also, when the grid fault is removed and the change in grid voltage falls below the reference value, the function switching command unit 96-1 issues a function switching command (switch on / off command) to the corresponding phase adjustment unit in the power control device 2 so that a function to adjust the phase is not used (or a function to decrease the degree of phase adjustment is used).

[0367] In the example described above, we explained an example where the conditions for simulating inertial response are met when the change amount or rate of change of the electrical quantity is equal to or greater than (or less than or equal to) the reference value. However, the conditions for simulating inertial response may also be met when the change amount or rate of change of the electrical quantity is not equal to or greater than (or less than or equal to) the reference value.

[0368] The power conversion device 3 according to the embodiment of 9-2 includes an electrical quantity change processing unit 10 and a power control device 2, as shown in Figure 24B. This power control device 2 corresponds to the power control device 2 shown in embodiments 7-1, 7-2, 7-3, 7-4, and 7-5 (Figures 20A, 20B, 20C, 20D, 20E, etc.). However, in this embodiment, instead of providing a coefficient change command unit 71 inside the power control device 2, a coefficient change command unit 96-2 having the same function as the coefficient change command unit 71 is provided outside the power control device 2.

[0369] The electrical quantity change processing unit 10 includes a reference value setting unit 90, a current measurement unit 91, a system voltage measurement unit 92, a phase calculation unit 93, an electrical quantity change calculation unit (electrical quantity change calculation means) 94, a comparison unit (comparison means) 95, and a coefficient change command unit (command means) 96-2.

[0370] The functions of the reference value setting unit 90, current measurement unit 91, system voltage measurement unit 92, phase calculation unit 93, electrical quantity change calculation unit 94, and comparison unit 95 are as described above.

[0371] The coefficient change command unit 96-2, in accordance with the information output from the comparison unit 95, gives a command to the corresponding phase adjustment unit in the power control device 2 (any of the phase adjustment units 11, 21, 32, 41-43, 52) to change the time constant and / or coefficient (coefficient change command) so that the value of the time constant and / or coefficient to be applied to the function used for phase adjustment in the corresponding phase adjustment unit in the power control device 2 is applied to the above function. Instead of giving a command to change the time constant and / or coefficient, the value of the time constant and / or coefficient may be given.

[0372] If the information output from the comparison unit 95 does not indicate that the conditions for performing inertial response simulation are met (for example, if the value is "0"), the coefficient change command unit 96-2 gives a command to change the time constant and / or coefficient to the corresponding phase adjustment unit in the power control device 2 so that a time constant and / or coefficient of value 0 is applied to the function, so that inertial response simulation is not performed. Instead of giving a command to change the time constant and / or coefficient, the value 0 may be given to the time constant and / or coefficient. On the other hand, if the information output from the comparison unit 95 indicates that the conditions for performing inertial response simulation are met (for example, if the value is "1"), the coefficient change command unit 96-2 gives a command to change the time constant and / or coefficient to the corresponding phase adjustment unit in the power control device 2 so that a time constant and / or coefficient of a predetermined value is applied to the function, so that inertial response simulation is performed. Instead of giving a command to change the time constant and / or coefficient, a predetermined value may be given to the time constant and / or coefficient.

[0373] For example, if a grid fault occurs and the change in grid voltage exceeds a reference value, the coefficient change command unit 96-2 issues a command to change the time constant and / or coefficient to the corresponding phase adjustment unit in the power control device 2 so that a time constant and / or coefficient that adjusts the phase is used (or a time constant and / or coefficient that increases the degree of phase adjustment is used). Also, if the grid fault is removed and the change in grid voltage falls below a reference value, the coefficient change command unit 96-2 issues a command to change the time constant and / or coefficient to the corresponding phase adjustment unit in the power control device 2 so that a coefficient that reduces the degree of phase adjustment is not used (or a coefficient that decreases the degree of phase adjustment is used).

[0374] In the example described above, we explained an example where the conditions for simulating inertial response are met when the change amount or rate of change of the electrical quantity is equal to or greater than (or less than or equal to) the reference value. However, the conditions for simulating inertial response may also be met when the change amount or rate of change of the electrical quantity is not equal to or greater than (or less than or equal to) the reference value.

[0375] The power conversion device 3 according to the 9-3 embodiment includes an electrical quantity change processing unit 10 and a power control device 2, as shown in Figure 24C. This power control device 2 corresponds to the power control device 2 shown in the 8th embodiment (Figure 22A, etc.). However, in this embodiment, instead of providing a circuit switching command unit 81 inside the power control device 2, a circuit switching command unit 96-3 having the same function as the circuit switching command unit 81 is provided outside the power control device 2.

[0376] The electrical quantity change processing unit 10 includes a reference value setting unit 90, a current measurement unit 91, a system voltage measurement unit 92, a phase calculation unit 93, an electrical quantity change calculation unit (electrical quantity change calculation means) 94, a comparison unit (comparison means) 95, and a circuit switching command unit (command means) 96-3.

[0377] The functions of the reference value setting unit 90, current measurement unit 91, system voltage measurement unit 92, phase calculation unit 93, electrical quantity change calculation unit 94, and comparison unit 95 are as described above.

[0378] The circuit switching command unit 96-3, in accordance with the information output from the comparison unit 95, specifies which of the first and second paths (bypass BP1, bypass BP2, bypass BP3, bypass BP4u, BP4v, BP4w, bypass BP5) in the power control device 2 shown in Figure 22A to be enabled, passing through the corresponding phase adjustment units (any of phase adjustment units 11, 21, 32, 41-43, 52), and issues switching commands (circuit switching commands) to the corresponding switching units (any of switching units SW1a and SW1b, SW2a and SW2b, SW3a and SW3b, SW4ua, SW4va, SW4wa, SW4ub, SW4vb, and SW4wb, and switching units SW5a and SW5b) in the power control device 2 to be enabled, so that only the specified path is enabled.

[0379] For example, if the information output from the comparison unit 95 does not indicate that the conditions for performing inertial response simulation are met (for example, if the value is "0"), the circuit switching command unit 96-3 issues a circuit switching command to the corresponding switching unit in the power control device 2 so that the second path becomes active and the first path becomes inactive, so that inertial response simulation is not performed. On the other hand, if the information output from the comparison unit 95 indicates that the conditions for performing inertial response simulation are met (for example, if the value is "1"), the circuit switching command unit 96-3 issues a circuit switching command to the corresponding switching unit in the power control device 2 so that the first path becomes active and the second path becomes inactive, so that inertial response simulation is performed.

[0380] For example, if a grid fault occurs and the change in grid voltage exceeds a reference value, the circuit switching command unit 96-3 issues a circuit switching command to the corresponding phase adjustment unit in the power control device 2 so that the first path, which adjusts the phase, is used. Furthermore, when the grid fault is eliminated and the change in grid voltage falls below the reference value, the circuit switching command unit 96-3 issues a circuit switching command to the corresponding phase adjustment unit in the power control device 2 so that the second path, which does not adjust the phase, is used.

[0381] In the example described above, we explained an example where the conditions for simulating inertial response are met when the change amount or rate of change of the electrical quantity is equal to or greater than (or less than or equal to) the reference value. However, the conditions for simulating inertial response may also be met when the change amount or rate of change of the electrical quantity is not equal to or greater than (or less than or equal to) the reference value.

[0382] Next, an example of the operation of the power converter 3 according to the 9-1 embodiment will be described with reference to the flowchart in Figure 25A.

[0383] In this embodiment, the reference value setting unit 90 sets a reference value for the amount or rate of change of an electrical quantity (voltage, current, power, phase, etc.) (step S50).

[0384] Furthermore, the current measurement unit 91 measures the AC waveform of the current (electric current) flowing through the output electrical circuit of the power converter 1 from the current signal supplied from the current transformer CT1, the system voltage measurement unit 92 measures the AC waveform of the system voltage from the voltage signal supplied from the instrument transformer VT, the phase calculation unit 93 determines the phase of the AC waveform of the voltage measured by the system voltage measurement unit 92, and the electric quantity change calculation unit 94 determines the amount or rate of change of the electric quantity obtained by the current measurement unit 91, the system voltage measurement unit 92, or the phase calculation unit 93 (step S51).

[0385] Next, the comparison unit 95 receives the value of the amount or rate of change of an electrical quantity (current, voltage, phase, etc.) obtained by the electrical quantity change calculation unit 94, and also receives a reference value corresponding to the amount or rate of change of the electrical quantity from the reference value setting unit 90. The comparison unit then performs a comparison of the two and outputs information indicating whether the amount or rate of change of the electrical quantity satisfies the conditions for performing inertial response simulation (step S52).

[0386] Next, the function switching command unit 96-1 determines whether the information output from the comparison unit 95 satisfies predetermined conditions (step S53). If the conditions are met, it issues a function switching command (switch on / off command) to the corresponding phase adjustment unit (one of the phase adjustment units 11, 21, 32, 41-43, or 52) in the power control device 2 (step S21-1).

[0387] If the information output from the comparison unit 95 does not indicate that the conditions for performing inertial response simulation are met, the function switching command unit 96-1 gives a function switching command (switch on / off command) to the corresponding phase adjustment unit in the power control device 2 so that the calculation process using the function is bypassed, preventing the inertial response simulation from being performed. On the other hand, if the information output from the comparison unit 95 indicates that the conditions for performing inertial response simulation are met, the function switching command unit 96-1 gives a function switching command (switch on / off command) to the corresponding phase adjustment unit in the power control device 2 so that a predetermined function is used for phase adjustment, enabling the inertial response simulation to be performed.

[0388] Next, an example of the operation of the power converter 3 according to the 9-2 embodiment will be explained with reference to the flowchart in Figure 25B.

[0389] The processes described in steps S50 to S52 above are also performed in this embodiment.

[0390] Next, the coefficient change command unit 96-2 determines whether the information output from the comparison unit 95 satisfies predetermined conditions (step S53). If the conditions are met, it issues a command to change the time constant and / or coefficient to the corresponding phase adjustment unit (one of the phase adjustment units 11, 21, 32, 41-43, or 52) in the power control device 2 (step S31-1).

[0391] If the information output from the comparison unit 95 does not indicate that the conditions for performing inertial response simulation are met, the coefficient change command unit 96-2 gives a command to change the time constant and / or coefficient to the corresponding phase adjustment unit in the power control device 2 so that a time constant and / or coefficient of value 0 is applied to the function, so that inertial response simulation is not performed. On the other hand, if the information output from the comparison unit 95 indicates that the conditions for performing inertial response simulation are met, the coefficient change command unit 96-2 gives a command to change the time constant and / or coefficient to the corresponding phase adjustment unit in the power control device 2 so that a time constant and / or coefficient of a predetermined value is applied to the function, so that inertial response simulation is performed.

[0392] Next, an example of the operation of the power converter 3 according to the 9-3 embodiment will be described with reference to the flowchart in Figure 25C.

[0393] The processes described in steps S50 to S52 above are also performed in this embodiment.

[0394] Next, the circuit switching command unit 96-3 determines whether the information output from the comparison unit 95 satisfies predetermined conditions (step S53). If the conditions are met, it issues switching commands (circuit switching commands) to the corresponding switching units in the power control device 2 (any of the switching units SW1a and SW1b, SW2a and SW2b, SW3a and SW3b, SW4ua, SW4va, SW4wa, SW4ub, SW4vb, and SW4wb, and SW5a and SW5b) so that only the first path including the corresponding phase adjustment unit (any of the phase adjustment units 11, 21, 32, 41-43, and 52) in the power control device 2 is active (step S41-1).

[0395] If the information output from the comparison unit 95 does not indicate that the conditions for performing inertial response simulation are met, the circuit switching command unit 96-3 issues a circuit switching command to the corresponding switching unit in the power control device 2 so that the second path becomes active and the first path becomes inactive, so that inertial response simulation is not performed. On the other hand, if the information output from the comparison unit 95 indicates that the conditions for performing inertial response simulation are met, the circuit switching command unit 96-3 issues a circuit switching command to the corresponding switching unit in the power control device 2 so that the first path becomes active and the second path becomes inactive, so that inertial response simulation is performed.

[0396] According to embodiments 9-1, 9-2, and 9-3, by switching the activation / deactivation of inertial response simulation in accordance with information from the comparison unit 95, stable control can be achieved without falling into a state of loss of synchronism or loss of control due to excessive control.

[0397] [Embodiments 10-1, 10-2, and 10-3] Next, embodiments 10-1, 10-2, and 10-3 will be described. In the following, the descriptions of parts common to embodiments 6-1, 6-2, 6-3, 6-4, and 6-5, embodiments 7-1, 7-2, 7-3, 7-4, and 7-5, and embodiment 8 will be omitted, and the descriptions will focus on the differences.

[0398] In embodiments 9-1, 9-2, and 9-3, examples of one type of electric quantity, change in electric quantity or rate of change, or reference value used to determine whether the conditions for performing inertial response simulation are met were described. However, in embodiments 10-1, 10-2, and 10-3, examples of multiple types of electric quantities, change in electric quantity or rate of change, or reference values ​​used to determine whether the conditions for performing inertial response simulation are met will be described.

[0399] Figure 26A shows an example of the configuration of a charging and discharging equipment having a power converter according to the 10-1 embodiment. Figure 26B shows an example of the configuration of a charging and discharging equipment having a power converter according to the 10-2 embodiment. Figure 26C shows an example of the configuration of a charging and discharging equipment having a power converter according to the 10-3 embodiment.

[0400] The power conversion device 3 according to the embodiment of 10-1 includes an electrical quantity change processing unit 10 and a power control device 2, as shown in Figure 26A. This power control device 2 corresponds to the power control device 2 shown in embodiments 6-1, 6-2, 6-3, 6-4, and 6-5 (Figures 18A, 18B, 18C, 18D, 18E, etc.). However, in this embodiment, instead of providing a function switching command unit 61 inside the power control device 2, a function switching command unit 103-1 having the same function as the function switching command unit 61 is provided outside the power control device 2.

[0401] The electrical quantity change processing unit 10 includes a current measurement unit 91, a system voltage measurement unit 92, a phase calculation unit 93, a reference value setting unit 100, an electrical quantity change calculation unit (electrical quantity change calculation means) 101, a comparison / determination unit (comparison means / determination means) 102, and a function switching command unit (command means) 103-1.

[0402] The functions of the current measurement unit 91, the system voltage measurement unit 92, and the phase calculation unit 93 are as described above.

[0403] The reference value setting unit 100 is equipped with a function (limit value setting function) for setting limit values ​​(upper limit and / or lower limit).

[0404] The reference value setting unit 100 includes a function to set reference values ​​(e.g., upper and / or lower limits) for electrical quantities (voltage, current, power, phase, etc.) or the amount or rate of change of electrical quantities, and a function to output the set reference values. The reference values ​​referred to here are, for example, at least one of six types of reference values, which consist of a reference value used for comparison with the value of current measured by the current measurement unit 91, a reference value used for comparison with the value of voltage measured by the system voltage measurement unit 92, a reference value used for comparison with the value of phase obtained by the phase calculation unit 93, a reference value used for comparison with the amount or rate of change of current of the current measurement unit 91 calculated by the electrical quantity change calculation unit 101, a reference value used for comparison with the amount or rate of change of voltage of the system voltage measurement unit 92 calculated by the electrical quantity change calculation unit 101, and a reference value used for comparison with the amount or rate of change of phase of the phase calculation unit 93 calculated by the electrical quantity change calculation unit 101. Here, an example is shown in which the unit is equipped with a function to set all six types of reference values ​​and a function to output the set reference values, but it is not limited to this example. The reference values ​​can be 2 to 5 types or even just 1 type.

[0405] The electrical quantity change calculation unit 101 determines the amount or rate of change of electrical quantities (current, voltage, phase, etc.) obtained by the current measurement unit 91, the system voltage measurement unit 92, or the phase calculation unit 93.

[0406] The electrical quantity change calculation unit 101 receives at least one of three values: the current value measured by the current measurement unit 91, the voltage value measured by the system voltage measurement unit 92, and the phase value determined by the phase calculation unit 93. This example shows a case where all three values ​​are input to the electrical quantity change calculation unit 101, but it is not limited to this example. Only two or one value may be input to the electrical quantity change calculation unit 101.

[0407] The comparison / determination unit 102 is equipped with a function for performing comparison processing (comparison function) and a function for performing determination processing (determination function).

[0408] The comparison function of the comparison / determination unit 102 includes the input of values ​​of electrical quantities (current, voltage, phase, etc.) obtained by the current measurement unit 91, the system voltage measurement unit 92, or the phase calculation unit 93, and / or the amount or rate of change of said electrical quantities, as well as input of a reference value corresponding to said electrical quantity and / or the amount or rate of change of said electrical quantities from the reference value setting unit 100, and outputting information indicating whether the values ​​of said electrical quantities (current, voltage, phase, etc.) and / or the amount or rate of change of said electrical quantities deviate from a predetermined reference value.

[0409] The comparison function of this comparison / determination unit 102 includes, for example, inputting the value of an electrical quantity (current, voltage, phase, etc.) obtained by the current measurement unit 91, the system voltage measurement unit 92, or the phase calculation unit 93, and / or the value of the amount of change or rate of change of said electrical quantity, as well as inputting a reference value corresponding to said electrical quantity and / or the amount of change or rate of change of said electrical quantity from the reference value setting unit 100, comparing the two, and outputting information indicating whether or not the value of said electrical quantity and / or the amount of change or rate of change of said electrical quantity deviates from the reference value.

[0410] The comparison / determination unit 102 includes a determination function that determines whether or not to switch functions based on the output of the comparison function of the comparison / determination unit 102 (information indicating whether or not the value has not deviated from the reference value).

[0411] The determination function of this comparison / determination unit 102 includes a function to determine whether the conditions for performing inertial response simulation are met based on information indicating whether the value of a first electrical quantity (e.g., the frequency of the system voltage of the power system S) or the amount or rate of change of that value is greater than or equal to or greater than a predetermined reference value (or less than or equal to a predetermined reference value), and information indicating whether the value of a second electrical quantity (e.g., the current of the power converter 1) or the amount or rate of change of that value is greater than or equal to or greater than a predetermined reference value (or less than or equal to a predetermined reference value), and to output the result of the determination. If the conditions are met, the unit outputs a value such as "1" as information indicating that the conditions for performing inertial response simulation are met, and if not, it outputs a value such as "0".

[0412] For example, if the conditions for performing inertial response simulation are met when the first electrical quantity is greater than or equal to a reference value and the second electrical quantity is less than or equal to a reference value, then "1" is output as the first comparison result when the first electrical quantity is greater than or equal to a reference value, and "1" is output as the second comparison result when the second electrical quantity is less than or equal to a reference value. The judgment function of the comparison / determination unit 102 outputs "1" as information indicating that the conditions for performing inertial response simulation are met when both the first and second comparison results are "1".

[0413] The function switching command unit 103-1, in accordance with the information output from the comparison / determination unit 102, specifies which function to be used for phase adjustment from among the multiple functions provided in the corresponding phase adjustment unit (any of the phase adjustment units 11, 21, 32, 41-43, 52) in the power control device 2, and gives a command (function switching command) to the corresponding phase adjustment unit in the power control device 2 to switch the function (switch on / off) so that the specified function is used for phase adjustment.

[0414] If the information output from the comparison / determination unit 102 does not indicate that the conditions for performing inertial response simulation are met (for example, if the value is "0"), the function switching command unit 103-1 gives a function switching command (switch on / off command) to the corresponding phase adjustment unit in the power control device 2 so that the calculation process by the function is bypassed and inertial response simulation is not performed. On the other hand, if the information output from the comparison / determination unit 102 indicates that the conditions for performing inertial response simulation are met (for example, if the value is "1"), the function switching command unit 103-1 gives a function switching command (switch on / off command) to the corresponding phase adjustment unit in the power control device 2 so that a predetermined function is used for phase adjustment so that inertial response simulation is performed.

[0415] For example, if a grid fault occurs and the grid voltage deviates from a reference value but the current does not deviate from a reference value, the function switching command unit 103-1 issues a function switching command (switch on / off command) to the corresponding phase adjustment unit in the power control device 2 so that a function to adjust the phase is used (or a function to increase the degree of phase adjustment is used). Also, when the grid fault is removed and the grid voltage falls below the reference value, the function switching command unit 103-1 issues a function switching command to the corresponding phase adjustment unit in the power control device 2 so that a function to reduce the degree of phase adjustment is not used (or a function to decrease the degree of phase adjustment is used). Similarly, if the current deviates from a reference value, the function switching command is issued to the corresponding phase adjustment unit in the power control device 2 so that a function to adjust the phase is not used (or a function to reduce the degree of phase adjustment is used).

[0416] The power conversion device 3 according to the embodiment of 10-2 includes an electrical quantity change processing unit 10 and a power control device 2, as shown in Figure 26B. This power control device 2 corresponds to the power control device 2 shown in embodiments 7-1, 7-2, 7-3, 7-4, and 7-5 (Figures 20A, 20B, 20C, 20D, 20E, etc.). However, in this embodiment, instead of providing a coefficient change command unit 71 inside the power control device 2, a coefficient change command unit 103-2 having the same function as the coefficient change command unit 71 is provided outside the power control device 2.

[0417] The electrical quantity change processing unit 10 includes a current measurement unit 91, a system voltage measurement unit 92, a phase calculation unit 93, a reference value setting unit 100, an electrical quantity change calculation unit (electrical quantity change calculation means) 101, a comparison / determination unit (comparison means / determination means) 102, and a coefficient change command unit (command means) 103-2.

[0418] The functions of the current measurement unit 91, the system voltage measurement unit 92, the phase calculation unit 93, the reference value setting unit 100, the electrical quantity change calculation unit 101, and the comparison / determination unit 102 are as described above.

[0419] The coefficient change command unit 103-2 issues a command to change the time constant and / or coefficient (coefficient change command) to the corresponding phase adjustment unit (any of the phase adjustment units 11, 21, 32, 41-43, 52) in the power control device 2, in accordance with the information output from the comparison unit / determination unit 102, so that the values ​​of the time constant and / or coefficient to be applied to the function used for adjusting the phase in the corresponding phase adjustment unit in the power control device 2 are applied. The coefficient change command unit 103-2 may also provide the values ​​of the time constant and / or coefficient instead of issuing a command to change the time constant and / or coefficient.

[0420] If the information output from the comparison / determination unit 102 does not indicate that the conditions for performing inertial response simulation are met (for example, if the value is "0"), the coefficient change command unit 103-2 issues a coefficient change command to the corresponding phase adjustment unit in the power control device 2 so that a time constant and / or coefficient of value 0 is applied to the function, thereby preventing inertial response simulation. On the other hand, if the information output from the comparison / determination unit 102 indicates that the conditions for performing inertial response simulation are met (for example, if the value is "1"), the coefficient change command unit 103-2 issues a time constant and / or coefficient change command to the corresponding phase adjustment unit in the power control device 2 so that a time constant and / or coefficient of a predetermined value is applied to the function, thereby preventing inertial response simulation.

[0421] For example, if a grid fault occurs and the change in grid voltage exceeds a reference value, but the current does not deviate from the reference value, the coefficient change command unit 103-2 issues a command to change the time constant and / or coefficient to the corresponding phase adjustment unit in the power control device 2 so that the time constant and / or coefficient for adjusting the phase is used (or so that the time constant and / or coefficient for increasing the degree of phase adjustment is used). Also, when the grid fault is removed and the change in grid voltage falls below the reference value, the coefficient change command unit 103-2 issues a command to change the coefficient to the corresponding phase adjustment unit in the power control device 2 so that the time constant and / or coefficient for adjusting the phase is not used (or so that the time constant and / or coefficient for decreasing the degree of phase adjustment is used). If the current deviates from the reference value, the coefficient change command unit 103-2 also issues a command to change the coefficient to the corresponding phase adjustment unit in the power control device 2 so that the time constant and / or coefficient for adjusting the phase is not used (or so that the time constant and / or coefficient for decreasing the degree of phase adjustment is used).

[0422] The power conversion device 3 according to the embodiment of 10-3 includes an electrical quantity change processing unit 10 and a power control device 2, as shown in Figure 26C. This power control device 2 corresponds to the power control device 2 shown in embodiments 6-1, 6-2, 6-3, 6-4, and 6-5 (Figures 18A, 18B, 18C, 18D, 18E, etc.). However, in this embodiment, instead of having a circuit switching command unit 81 inside the power control device 2, a circuit switching command unit 103-3 having the same function as the circuit switching command unit 81 is provided outside the power control device 2.

[0423] The electrical quantity change processing unit 10 includes a current measurement unit 91, a system voltage measurement unit 92, a phase calculation unit 93, a reference value setting unit 100, an electrical quantity change calculation unit (electrical quantity change calculation means) 101, a comparison / determination unit (comparison means / determination means) 102, and a circuit switching command unit (command means) 103-3.

[0424] The functions of the current measurement unit 91, the system voltage measurement unit 92, the phase calculation unit 93, the reference value setting unit 100, the electrical quantity change calculation unit 101, and the comparison / determination unit 102 are as described above.

[0425] The circuit switching command unit 103-3, in accordance with the information output from the comparison / determination unit 102, specifies which of the first and second paths (bypass BP1, bypass BP2, bypass BP3, bypass BP4u, BP4v, BP4w, bypass BP5) in the power control device 2 shown in Figure 22A to be enabled, passing through the corresponding phase adjustment unit (any of phase adjustment units 11, 21, 32, 41~43, 52), and issues switching commands (circuit switching commands) to the corresponding switching units (any of switching units SW1a and SW1b, SW2a and SW2b, SW3a and SW3b, SW4ua, SW4va, SW4wa, SW4ub, SW4vb, and SW4wb, and switching units SW5a and SW5b) in the power control device 2 to be enabled, and issues switching commands (circuit switching commands) to the corresponding switching units (any of switching units SW1a and SW1b, SW2a and SW2b, SW3a and SW3b, SW4ua, SW4va, SW4wa, SW4ub, SW4vb, and SW4wb, and switching units SW5a and SW5b) in the power control device 2 to be enabled, so that only the specified path is enabled.

[0426] If the information output from the comparison / determination unit 102 does not indicate that the conditions for performing inertial response simulation are met (for example, if the value is "0"), the circuit switching command unit 103-3 issues a circuit switching command to the corresponding phase adjustment unit in the power control device 2 so that the second path becomes active and the first path becomes inactive, preventing the inertial response simulation from being performed. On the other hand, if the information output from the comparison / determination unit 102 indicates that the conditions for performing inertial response simulation are met (for example, if the value is "1"), the circuit switching command unit 103-3 issues a circuit switching command to the corresponding phase adjustment unit in the power control device 2 so that the first path becomes active and the second path becomes inactive, enabling the inertial response simulation from being performed.

[0427] For example, if a system fault occurs and the system voltage exceeds a reference value while the current does not deviate from the reference value, the circuit switching command unit 103-3 issues a circuit switching command to the corresponding phase adjustment unit in the power control device 2 so that the first path, which adjusts the phase, is used. Furthermore, when the system fault is removed and the change in system voltage falls below the reference value, the circuit switching command unit 103-3 issues a circuit switching command to the corresponding phase adjustment unit in the power control device 2 so that the second path, which does not adjust the phase, is used. If the current deviates from the reference value, the circuit switching command unit 103-3 also issues a circuit switching command to the corresponding phase adjustment unit in the power control device 2 so that the second path, which does not adjust the phase, is used.

[0428] Figure 26D shows an example of the functional configuration of the comparison / determination unit 102 provided in the power converter 3 according to the 10-1, 10-2, and 10-3 embodiments.

[0429] In the example shown in Figure 26D, the functions of the reference value setting unit 100 described above are assumed to be built into the comparison / determination unit 102. The functions of the limit value / reference value setting unit 100 are realized within the comparison / determination unit 102 by the first reference value setting unit 102c and the second reference value setting unit 102f.

[0430] The comparison / determination unit 102 includes a voltage measurement unit 102a, a change amount calculation unit 102b, a first reference value setting unit 102c, a voltage change amount comparison unit 102d, a current measurement unit 102e, a second reference value setting unit 102f, a current comparison unit 102g, and a determination calculation unit 102h.

[0431] The comparison / determination unit 102 receives, for example, a signal of the system voltage measured by the system voltage measurement unit 92, as well as a signal of the circuit current measured by the current measurement unit 91.

[0432] The voltage measurement unit 102a measures the voltage from the system voltage signal input to the comparison / determination unit 102. The change amount calculation unit 102b measures the change amount of the voltage measured by the voltage measurement unit 102a. The first reference value setting unit 102c sets a reference value for the voltage change amount. The voltage change amount comparison unit 102d compares the change amount measured by the change amount calculation unit 102b with the reference value and outputs a value such as "1" if the change amount is equal to or exceeds the reference value, and outputs a value such as "0" otherwise.

[0433] Meanwhile, the current measurement unit 102e measures the value of the circuit current input to the comparison / determination unit 102. The second reference value setting unit 102f sets a reference value for the current. The current comparison unit 102g compares the current value measured by the current measurement unit 102e with the reference value and outputs a value such as "1" if the current value is less than or equal to the reference value, i.e., if it does not deviate from the reference value, and outputs a value such as "0" otherwise.

[0434] The determination calculation unit 102h receives the value output from the voltage change amount comparison unit 102d and the value output from the current comparison unit 102g. If the value output from the voltage change amount comparison unit 102d is "1" and the value output from the current comparison unit 102g is also "1", the determination calculation unit 102h outputs a value of "1" (i.e., information indicating that the system is in a suitable state for performing inertial response simulation), and if not, it outputs a value of "0" (i.e., information indicating that the system is not in a suitable state for performing inertial response simulation).

[0435] In this example, the two types of electrical quantities input to the comparison / determination unit 102 are shown to be "voltage" and "current," but these may be changed to other electrical quantities (power, phase, etc.). Furthermore, the two types of electrical quantities may be different or the same.

[0436] Next, an example of the operation of the power converter 3 according to the 10-1 embodiment will be described with reference to the flowchart in Figure 27A.

[0437] In this embodiment, the reference value setting unit 100 sets reference values ​​for electrical quantities (voltage, current, power, phase, etc.) and / or the amount or rate of change of electrical quantities (step S60).

[0438] Furthermore, the current measurement unit 91 measures the AC waveform of the current (electric current) flowing through the output electrical circuit of the power converter 1 from the current signal supplied from the current transformer CT1, the grid voltage measurement unit 92 measures the AC waveform of the grid voltage from the voltage signal supplied from the instrument transformer VT, the phase calculation unit 93 determines the phase of the AC waveform of the voltage measured by the grid voltage measurement unit 92, and the electric quantity change calculation unit 101 determines the amount or rate of change of the electric quantity obtained by the current measurement unit 91, the grid voltage measurement unit 92, or the phase calculation unit 93 (step S61).

[0439] Next, the comparison / determination unit 102 receives the values ​​of electrical quantities (current, voltage, phase, etc.) obtained by the current measurement unit 91, the system voltage measurement unit 92, or the phase calculation unit 93, and / or the values ​​of the amount of change or rate of change of electrical quantities (current, voltage, phase, etc.) determined by the electrical quantity change calculation unit 101, and receives a reference value corresponding to the electrical quantity or the amount of change or rate of change of the electrical quantity from the reference value setting unit 100, compares the two, and outputs information indicating whether the amount of change or rate of change of the electrical quantity deviates from the reference value (step S62).

[0440] Next, the comparison / determination unit 102 performs a determination process to determine whether or not the conditions for performing inertial response simulation are met (step S62).

[0441] The comparison function of the comparison / determination unit 102 includes, for example, inputting values ​​of electrical quantities (current, voltage, phase, etc.) obtained by the current measurement unit 91, the system voltage measurement unit 92, or the phase calculation unit 93, and / or values ​​of the amount of change or rate of change of electrical quantities (current, voltage, phase, etc.) determined by the electrical quantity change calculation unit 101, as well as inputting a reference value corresponding to the electrical quantity and / or the amount of change or rate of change of the electrical quantity from the reference value setting unit 100, comparing the two, and outputting information indicating whether the value of the electrical quantity deviates from the reference value.

[0442] On the other hand, the comparison / determination unit 102's determination function includes a function to determine whether or not to switch functions based on the output of the comparison function of the comparison / determination unit 102 (information indicating whether or not the system is not deviating from a reference value). For example, it determines whether the conditions for performing inertial response simulation are met based on information indicating whether the value of a first electrical quantity (e.g., the frequency of the system voltage of power system S) or the amount or rate of change of that value is greater than or equal to or greater than a predetermined reference value (or less than or equal to a predetermined reference value), and information indicating whether the value of a second electrical quantity (e.g., the current of power converter 1) or the amount or rate of change of that value is greater than or equal to or greater than a predetermined reference value (or less than or equal to a predetermined reference value), and outputs the result of the determination.

[0443] Next, the function switching command unit 103-1 issues a function switching command to the corresponding phase adjustment unit (one of the phase adjustment units 11, 21, 32, 41-43, or 52) in the power control device 2, according to the information output from the comparison / determination unit 102 (step S21-2).

[0444] If the information output from the comparison / determination unit 102 does not indicate that the conditions for performing inertial response simulation are met (for example, if the value is "0"), the function switching command unit 103-1 issues a function switching command (switch on / off command) to the corresponding phase adjustment unit in the power control device 2 so that the calculation process by the function is bypassed and inertial response simulation is not performed. On the other hand, if the information output from the comparison / determination unit 102 indicates that the conditions for performing inertial response simulation are met (for example, if the value is "1"), the function switching command unit 103-1 issues a function switching command (switch on / off command) to the corresponding phase adjustment unit in the power control device 2 so that a predetermined function is used for phase adjustment so that inertial response simulation is performed.

[0445] Next, an example of the operation of the power converter 3 according to the 10-2 embodiment will be described with reference to the flowchart in Figure 27B.

[0446] The processes described in steps S60, S61, and S62 above are also performed in this embodiment.

[0447] Next, the coefficient change command unit 103-2 gives a command to change the time constant and / or coefficient to the corresponding phase adjustment unit (any of the phase adjustment units 11, 21, 32, 41-43, 52) in the power control device 2 according to the information output from the comparison / determination unit 102 (step S31-2).

[0448] If the information output from the comparison / determination unit 102 does not indicate that the conditions for performing inertial response simulation are met, the coefficient change command unit 103-2 gives a command to change the time constant and / or coefficient to the corresponding phase adjustment unit in the power control device 2 so that a time constant and / or coefficient of value 0 is applied to the function, so that inertial response simulation is not performed. On the other hand, if the information output from the comparison / determination unit 102 indicates that the conditions for performing inertial response simulation are met, the coefficient change command unit 103-2 gives a command to change the time constant and / or coefficient to the corresponding phase adjustment unit in the power control device 2 so that a time constant and / or coefficient of a predetermined value is applied to the function, so that inertial response simulation is performed.

[0449] Next, an example of the operation of the power converter 3 according to the 10-3 embodiment will be described with reference to the flowchart in Figure 27C.

[0450] The processes described in steps S60, S61, and S62 above are also performed in this embodiment.

[0451] Next, the circuit switching command unit 103-3 determines whether the information output from the comparison / determination unit 102 satisfies predetermined conditions (step S63). If the conditions are met, it issues switching commands (circuit switching commands) to the corresponding switching units in the power control device 2 (any of switching units SW1a and SW1b, SW2a and SW2b, SW3a and SW3b, SW4ua, SW4va, SW4wa, SW4ub, SW4vb, and SW4wb, and SW5a and SW5b) so that only the first path including the corresponding phase adjustment unit (any of phase adjustment units 11, 21, 32, 41-43, and 52) in the power control device 2 is active (step S41-1).

[0452] If the information output from the comparison / determination unit 102 does not indicate that the conditions for performing inertial response simulation are met, the circuit switching command unit 103-3 issues a circuit switching command to the corresponding switching unit in the power control device 2 so that the second path becomes active and the first path becomes inactive, preventing the inertial response simulation from being performed. On the other hand, if the information output from the comparison / determination unit 102 indicates that the conditions for performing inertial response simulation are met, the circuit switching command unit 103-3 issues a circuit switching command to the corresponding switching unit in the power control device 2 so that the first path becomes active and the second path becomes inactive, enabling the inertial response simulation from being performed.

[0453] According to embodiments 10-1, 10-2, and 10-3, appropriate control can be achieved by switching the activation / deactivation of inertial response simulation or adjusting the effect of inertial response simulation in accordance with information from the comparison / determination unit 102, and stable control can be achieved without falling into a state of loss of synchronism or loss of control due to excessive control.

[0454] [Embodiment 11] Next, we will describe the eleventh embodiment. In the following, we will omit the explanation of parts that are common with the first embodiment and focus on the parts that are different.

[0455] Figure 28 is a conceptual diagram showing an example of the configuration of a charge / discharge facility having a power converter according to the eleventh embodiment. In Figure 28, elements common to Figure 2 are denoted by the same reference numerals. Here, an example is shown where the power converter 3 is discharging. Figure 28 also shows the situation when the grid frequency decreases in this embodiment. The situations when the grid frequency is stable and when the grid frequency increases in this embodiment can be easily inferred from the descriptions of each embodiment described above, so their illustrations and explanations are omitted.

[0456] In the first embodiment described above, when the phase of an electrical quantity such as the system voltage fluctuates due to frequency fluctuations in an AC electrical circuit such as a power system S, even if the input / output command value (such as the active power control command value) of the power converter 3 remains constant, an example was shown in which the difference between the phase of the electrical quantity (voltage, current, power, etc.) input / output to the power converter 3 and the phase of the electrical quantity (voltage, current, power, etc.) of the electrical circuit such as the power system S is changed by changing the phase supplied to the voltage command value calculation unit 2c.

[0457] In contrast, this 11th embodiment shows an example in which the input and output (voltage, current, power, etc.) of the power converter 3 are changed not by changing the phase supplied to the voltage command value calculation unit 2c, but by adding an inertia simulation control signal given by the inertia simulation control signal generation unit 15 to the active power control command value supplied to the power control device 2 from the active power control command value calculation unit 202 as described above.

[0458] The power control device 2 according to the eleventh embodiment, as shown in Figure 28, further includes an inertia simulation control signal generation unit (control signal generation means) 15, in addition to the components shown in the first embodiment (Figure 2, etc.).

[0459] As described above, the phase adjustment unit 11 adjusts the phase of the voltage obtained by the phase calculation unit 2b as needed. This phase adjustment unit 11, for example, calculates and outputs a value obtained by applying a first-order lag calculation of angular velocity to the phase adjustment (for example, the adjusted phase value (θlag) obtained by multiplying the difference (ωdif) between the angular velocity value (ω) of the output (θ) of the phase calculation unit 2b and the first-order lag value of angular velocity (ωlag) by a coefficient (K) and time (Δt). The calculation performed by the phase adjustment unit 11 is the same as the calculation performed by the phase adjustment unit 11 in the first embodiment.

[0460] The inertia simulation control signal generation unit 15 receives a signal (inertia simulation control signal θdif) indicating the difference between the phase (θ) obtained by the phase calculation unit 2b and the phase (θlag) after adjustment by the phase adjustment unit 11, and generates a value by applying a function (e.g., sinθ) to convert the value, multiplying it by a coefficient, or converting it to a pu value as needed. The inertia simulation control signal generation unit 15 generates an inertia simulation control signal (Pvic) by performing the following calculations, for example.

[0461] θdif = θlag - θ Pvic = sin(θdif) (An example of using a function for θdif to convert it into an inertia-simulating control signal) Pvic = K·θdif (Example of multiplying θdif by a coefficient to convert it into an inertia-simulating control signal) Pvic = K·θdif / (2·π) (An example of converting θdif to a pu value and then multiplying it by a coefficient to obtain an inertia-simulating control signal.) Pvic = K·sin(θdif) (An example of using a function for θdif and then multiplying it by a coefficient to obtain an inertia-simulating control signal.) The inertia simulation control signal generated by the inertia simulation control signal generation unit 15 is added to the active power control command value supplied from the active power control command value calculation unit 202 to the power control device 2. For example, the inertia simulation control signal generated by the inertia simulation control signal generation unit 15 is supplied to the calculation unit 3a as shown in Figure 28.

[0462] As described above, the active power control command value calculation unit 202 receives, for example, an automatic frequency control command value (AFC command value) and / or a governor-free signal transmitted from a higher-level control system, and outputs an active power control command value. The active power control command value output from the active power control command value calculation unit 202 is transmitted to the calculation unit 3a in the power control device 2.

[0463] The calculation unit 3a receives the active power control command value output from the active power control command value calculation unit 202, as well as the active power measurement value output from the active power and reactive power calculation unit 201, and outputs the difference between the two (active power deviation), while adding the inertia simulation control signal provided by the inertia simulation control signal generation unit 15. The output of the calculation unit 3a is sent to the d-axis current command value calculation unit 3b.

[0464] The d-axis current command value calculation unit 3b receives the output of the calculation unit 3a, calculates the d-axis current command value based on the output of the calculation unit 3a, and outputs it. The d-axis current command value is sent to the calculation unit 3c. The calculation unit 3c receives the d-axis current command value as well as the d-axis current measurement value output from the power converter current dq conversion unit 2g, and outputs the d-axis current deviation as the difference between the two. The d-axis current deviation is sent to the voltage command value calculation unit 2c.

[0465] The voltage command value calculation unit 2c calculates and outputs a voltage command value from the voltage phase obtained by the phase calculation unit 2b, the d-axis current deviation, and the q-axis current deviation.

[0466] The two-phase to three-phase conversion unit 2d converts the voltage command value into a command value for a three-phase voltage waveform and outputs it (for example, it calculates and outputs the values ​​obtained by converting the α-axis voltage command value and β-axis voltage command value into a three-phase AC voltage command value).

[0467] • During discharge The operation of the power converter 3 while it is discharging will be explained with reference to Figure 28.

[0468] In this embodiment, when the system frequency decreases, the phase angle of the input signal of the phase adjustment unit 11 (output signal of the phase calculation unit 2b) becomes, for example, -30° as shown in vector A1, and the phase angle of the output signal of the phase adjustment unit 11 (input signal of the inertia simulation control signal generation unit 15) becomes, for example, -15° as shown in vector A2. At this time, the difference between the output signal (-15°) and the input signal (-30°) of the phase adjustment unit 11 becomes 15°, and the value of the inertia simulation control signal output from the inertia simulation control signal generation unit 15 becomes, for example, sin(15°) (when sinθ is used as the conversion function to obtain the inertia simulation control signal).

[0469] If the calculation unit 3a does not receive an inertia simulation control signal output from the inertia simulation control signal generation unit 15 (or if it receives an inertia simulation control signal with a value of 0), the voltage command value output from the voltage command value calculation unit 2c will be a value calculated from the difference (active power deviation) between the output of the active power control command value calculation unit 202 and the outputs of the active power and reactive power calculation unit 201.

[0470] In contrast, as in this example, when the calculation unit 3a receives an inertia simulation control signal of sin(15°) output from the inertia simulation control signal generation unit 15, the output of the calculation unit 3a becomes larger by the amount obtained by adding the value of the inertia simulation control signal (sin(15°)).

[0471] Consequently, the active power output (discharged) from power converter 1 increases by the amount of the inertia simulation control signal.

[0472] In this embodiment, when the grid frequency increases, the grid voltage, the output signal of the phase calculation unit 2b, the output signal of the phase adjustment unit 11, the output signal of the inertia simulation control signal generation unit 15, the output signal of the voltage command value calculation unit 2c, and the output of the power converter 1 change in the opposite direction to when the grid frequency decreases. For example, suppose the phase angle of the input signal of the phase adjustment unit 11 (the output signal of the phase calculation unit 2b) becomes 30°, and the phase angle of the output signal of the phase adjustment unit 11 (the input signal of the inertia simulation control signal generation unit 15) becomes 15°. At this time, the difference between the output signal (15°) and the input signal (30°) of the phase adjustment unit 11 becomes -15°, and the value of the inertia simulation control signal output from the inertia simulation control signal generation unit 15 becomes, for example, sin(-15°), which is a negative value. In other words, in this embodiment, when the grid frequency increases, the output of the calculation unit 3a becomes smaller by the value of the simulated inertia control signal than when the grid frequency is stable, due to the action of the phase adjustment unit 11 and the inertia simulation control signal generation unit 15 described above. Consequently, the active power output (discharged) from the power converter 1 becomes smaller by the value of the simulated inertia control signal than when the grid frequency is stable.

[0473] • When charging When the power converter 3 is charging, the relationship between the increase or decrease of the inertia simulation control signal and the increase or decrease of the absolute value of the active power of the power converter 3 is reversed compared to when it is discharging. For example, if the active power in the discharge direction is positive and the active power in the charging direction is negative, when the value of the positive phase velocity adjustment difference signal is added, the absolute value of the active power in the discharge direction increases, and the absolute value of the active power in the charging direction decreases. Conversely, when the value of the negative inertia simulation control signal is added, the absolute value of the active power in the discharge direction decreases, and the absolute value of the command value in the charging direction increases.

[0474] In other words, in this embodiment, when the grid frequency decreases, the absolute value of the output of the calculation unit 3a becomes smaller than the absolute value of the output of the calculation unit 3a when the grid frequency is stable by the value of the simulated inertia control signal, due to the action of the phase adjustment unit 11 and the inertia simulated control signal generation unit 15 described above, and the power input (charged) to the power converter 1 becomes smaller than when the grid frequency is stable. That is, when the phase of the grid voltage changes due to a decrease in the grid frequency, the power converter 1 reduces the power input (charged) to suppress the decrease in grid frequency.

[0475] Furthermore, in this embodiment, when the grid frequency increases, the absolute value of the output of the calculation unit 3a becomes larger than the absolute value of the output of the calculation unit 3a when the grid frequency is stable by the value of the inertia simulation control signal, due to the action of the phase adjustment unit 11 and the inertia simulation control signal generation unit 15 described above. As a result, the power input (charged) to the power converter 1 becomes larger when the grid frequency increases than when the grid frequency is stable. In other words, when the phase of the grid voltage changes with an increase in the grid frequency, the power converter 1 increases the power input (charged) to suppress the increase in the grid frequency.

[0476] Next, an example of the operation of the power control device 2 according to the 11th embodiment will be described with reference to the flowchart in Figure 29. Here, the explanation of parts common to the flowchart in Figure 7A shown in the first embodiment will be omitted, and the differences will be explained.

[0477] The processes described in steps S1 and S2 above are also performed in this embodiment.

[0478] Next, the phase adjustment unit 11 adjusts the phase of the voltage obtained by the phase calculation unit 2b (step S71). The phase adjustment unit 11, for example, applies a first-order lag calculation of angular velocity to the phase adjustment and outputs a value obtained by multiplying the difference between the angular velocity value output by the phase calculation unit 2b and the first-order lag value of angular velocity by a coefficient and time.

[0479] Next, the inertia simulation control signal generation unit 15 generates a signal (inertia simulation control signal) that shows the difference between the phase (θ) obtained by the phase calculation unit 2b, the phase (θlag) after adjustment by the phase adjustment unit 11, and the phase (θ) before adjustment (step S72).

[0480] The inertia simulation control signal generated by the inertia simulation control signal generation unit 15 in this manner is added to the active power control command value supplied from the active power control command value calculation unit 202 to the power control device 2 (step S73).

[0481] For example, the simulated inertia control signal generated by the simulated inertia control signal generation unit 15 is supplied to the calculation unit 3a. The calculation unit 3a receives the active power control command value output from the active power control command value calculation unit 202, as well as the active power measurement value output from the active power and reactive power calculation unit 201, and outputs the difference between the two (active power deviation), adding the simulated inertia control signal provided by the simulated inertia control signal generation unit 15. The output of the calculation unit 3a is sent to the d-axis current command value calculation unit 3b. The d-axis current command value calculation unit 3b receives the output of the calculation unit 3a and outputs a d-axis current command value based on the output of the calculation unit 3a. The d-axis current command value is sent to the calculation unit 3c. The calculation unit 3c receives the d-axis current command value as well as the d-axis current measurement value output from the power converter current dq conversion unit 2g, and outputs the d-axis current deviation as the difference between the two. The d-axis current deviation is sent to the voltage command value calculation unit 2c.

[0482] Next, the voltage command value calculation unit 2c calculates and outputs a voltage command value from the voltage phase obtained by the phase calculation unit 2b, the d-axis current deviation, and the q-axis current deviation (step S3).

[0483] Next, the two-phase to three-phase conversion unit 2d converts the voltage command value into a command value for a three-phase voltage waveform and outputs it (step S4).

[0484] The command values ​​of the three-phase voltage waveforms generated by the two-phase to three-phase conversion unit 2d are sent to the U-phase signal generation unit 5A, the V-phase signal generation unit 5B, and the W-phase signal generation unit 5C, respectively, to generate signals for the U-phase, V-phase, and W-phase. These signals are then supplied to the power converter 1, and the input and output of the power converter 1 are controlled.

[0485] As a result, for example, when the power converter 3 is discharging, if the grid frequency decreases, the output of the calculation unit 3a increases by the amount of the output (positive value) of the inertia simulation control signal generation unit 15, and the power converter 1 increases the power it outputs (discharges), suppressing the decrease in grid frequency. On the other hand, if the grid frequency increases, the output of the calculation unit 3a decreases by the amount of the output (negative value) of the inertia simulation control signal generation unit 15, and the power converter 1 decreases the power it outputs (discharges), suppressing the increase in grid frequency.

[0486] Furthermore, when the power converter 3 is charging, if the grid frequency decreases, the absolute value of the output of the calculation unit 3a decreases by the amount of the output (positive value) of the inertia simulation control signal generation unit 15, and the power converter 1 reduces the power it inputs (charges), suppressing the decrease in grid frequency. On the other hand, if the grid frequency increases, the absolute value of the output of the calculation unit 3a increases by the amount of the output (negative value) of the inertia simulation control signal generation unit 15, and the power converter 1 increases the power it inputs (charges), suppressing the increase in grid frequency.

[0487] According to the 11th embodiment, when the phase of an electrical quantity such as the system voltage changes due to frequency fluctuations in an AC electrical circuit such as a power system S, the electrical quantity (voltage, current, power, etc.) input and output to the power converter 3 can be changed by adding an inertia simulation control signal to the active power control command value supplied from the active power control command value calculation unit 202 to the power control device 2.

[0488] This makes it possible to achieve operation similar to the inertial response in a synchronous machine (simulation of inertial response), thereby suppressing frequency fluctuations and oscillations in the electrical circuit and contributing to frequency stabilization of the electrical circuit.

[0489] [Twelfth Embodiment] Next, we will describe the twelfth embodiment. In the following, we will omit the explanation of parts that are common with the eleventh embodiment and focus on the differences.

[0490] Figure 30 is a conceptual diagram showing an example of the configuration of a charging and discharging equipment having a power conversion device according to the twelfth embodiment. In Figure 30, elements common to Figure 28 are denoted by the same reference numerals.

[0491] In the aforementioned 11th embodiment, an example was shown in which the input and output (voltage, current, power, etc.) of the power converter 3 are changed by adding an inertia simulation control signal to the active power control command value supplied from the active power control command value calculation unit 202 to the calculation unit 3a in the power control device 2.

[0492] In contrast, this twelfth embodiment shows an example in which the input and output (voltage, current, power, etc.) of the power converter 3 are changed by adding an inertia simulation control signal to the d-axis current command value supplied from the d-axis current command value calculation unit 3b to the calculation unit 3c.

[0493] The inertia simulation control signal generation unit 15 according to the 12th embodiment generates a signal (inertia simulation control signal) that indicates the difference between the phase obtained by the phase calculation unit 2b and the phase adjusted by the phase adjustment unit 11, and, as necessary, converts the value using a function (e.g., sinθ), multiplies it by a coefficient, or converts it to a pu value. However, the inertia simulation control signal generated by this inertia simulation control signal generation unit 15 is not added to the active power control command value supplied from the active power control command value calculation unit 202 to the power control device 2, but is added to the current command value generated within the power control device 2. For example, the inertia simulation control signal generated by the inertia simulation control signal generation unit 15 is not supplied to the calculation unit 3a, but is supplied to the calculation unit 3c as shown in Figure 30. The calculations performed by the inertia simulation control signal generation unit 15 are the same as those performed by the inertia simulation control signal generation unit 15 in the 11th embodiment described above.

[0494] The calculation unit 3c receives the d-axis current command value output from the d-axis current command value calculation unit 3b, as well as the d-axis current measurement value output from the power converter current dq conversion unit 2g, and outputs the difference between the two (d-axis current deviation). At the same time, it adds the inertia simulation control signal provided by the inertia simulation control signal generation unit 15. The d-axis current deviation is sent to the voltage command value calculation unit 2c.

[0495] The voltage command value calculation unit 2c calculates and outputs a voltage command value from the voltage phase obtained by the phase calculation unit 2b, the d-axis current deviation, and the q-axis current deviation.

[0496] The two-phase to three-phase conversion unit 2d converts the voltage command value into a command value for a three-phase voltage waveform and outputs it (for example, it calculates and outputs the values ​​obtained by converting the α-axis voltage and β-axis voltage command values ​​into three-phase AC command values).

[0497] • During discharge In this embodiment, the effect when the grid frequency decreases is the same as in the 11th embodiment. Compared to when the frequency is stable, the output value of the calculation unit 3c increases by the amount of the inertia simulation control signal value (positive value) added, and the active power output (discharged) from the power converter 1 also increases. The effect when the grid frequency increases is also the same as in the 11th embodiment. Compared to when the frequency is stable, the output value of the calculation unit 3c decreases by the amount of the inertia simulation control signal (negative value) added, and the active power output (discharged) from the power converter 1 also decreases.

[0498] • When charging The effect when the frequency decreases while the power converter 3 is charging is the same as in the 11th embodiment. Compared to when the frequency is stable, the absolute value of the output (negative value) of the calculation unit 3c becomes smaller by the amount of the inertia simulation control signal (positive value) added, and the active power input (charged) to the power converter 1 also decreases. The effect when the frequency increases is also the same as in the 11th embodiment. Compared to when the frequency is stable, the absolute value of the output (negative value) of the calculation unit 3c becomes larger by the amount of the inertia simulation control signal (negative value) added, and the active power input (charged) to the power converter 1 also decreases.

[0499] Next, an example of the operation of the power control device 2 according to the 12th embodiment will be described with reference to the flowchart in Figure 31. Here, the explanation of parts common to the flowchart in Figure 29 shown in the 11th embodiment will be omitted, and the differences will be explained.

[0500] The processes described in steps S1, S2, S71, and S72 above are also performed in this embodiment.

[0501] The inertia simulation control signal generated by the inertia simulation control signal generation unit 15 is used to calculate the current command value generated in the power control device 2 (step S73-1).

[0502] For example, the simulated inertia control signal generated by the simulated inertia control signal generation unit 15 is supplied to the calculation unit 3c. The calculation unit 3c receives the d-axis current command value output from the d-axis current command value calculation unit 3b, as well as the measured d-axis current value output from the power converter current dq conversion unit 2g, and outputs the difference between the two (d-axis current deviation), adding the simulated inertia control signal provided by the simulated inertia control signal generation unit 15. The d-axis current deviation is sent to the voltage command value calculation unit 2c.

[0503] After this, the same process as in steps S3 and S4 described above is performed.

[0504] The command values ​​of the three-phase voltage waveforms generated by the two-phase to three-phase conversion unit 2d are sent to the U-phase signal generation unit 5A, the V-phase signal generation unit 5B, and the W-phase signal generation unit 5C, respectively, to generate signals for the U-phase, V-phase, and W-phase. These signals are then supplied to the power converter 1, and the input and output of the power converter 1 are controlled.

[0505] As a result, for example, when the power converter 3 is discharging, if the grid frequency decreases, the output of the calculation unit 3c increases by the amount of the output (positive value) of the inertia simulation control signal generation unit 15, and the power converter 1 increases the power it outputs (discharges), suppressing the decrease in grid frequency. On the other hand, if the grid frequency increases, the output of the calculation unit 3c decreases by the amount of the output (negative value) of the inertia simulation control signal generation unit 15, and the power converter 1 decreases the power it outputs (discharges), suppressing the increase in grid frequency.

[0506] Furthermore, when the power converter 3 is charging, if the grid frequency decreases, the absolute value of the output of the calculation unit 3c decreases by the amount of the output (positive value) of the inertia simulation control signal generation unit 15, and the power converter 1 reduces the power it inputs (charges), suppressing the decrease in grid frequency. On the other hand, if the grid frequency increases, the absolute value of the output of the calculation unit 3c increases by the amount of the output (negative value) of the inertia simulation control signal generation unit 15, and the power converter 1 increases the power it inputs (charges), suppressing the increase in grid frequency.

[0507] According to the 12th embodiment, when the phase of an electrical quantity such as the system voltage changes due to frequency fluctuations in an AC electrical circuit such as a power system S, the electrical quantity (voltage, current, power, etc.) input and output to the power converter 3 can be changed by adding an inertia simulation control signal to the d-axis current command value supplied from the d-axis current command value calculation unit 3b to the calculation unit 3c.

[0508] This makes it possible to achieve operation similar to the inertial response in a synchronous machine (simulation of inertial response), thereby suppressing frequency fluctuations and oscillations in the electrical circuit and contributing to frequency stabilization of the electrical circuit.

[0509] In the embodiments described above, examples were shown where the control target (power converter 1) of the power control device 2 is a power converter for a storage battery. However, the control target is not limited to this. For example, power storage devices such as electric vehicle charging devices, electric double-layer capacitors, flywheels, superconducting coils, and hydrogen storage devices, power generation devices such as variable-speed pumped-storage hydroelectric power plants, fuel cells, wind power plants, or solar power plants, and power converters applied to loads such as refrigerators, air conditioners, pumps, and fans may also be used as control targets. In other words, with the exception of power converters that require high-precision control (for example, power converters for rolling mills), almost all power converters can be used as control targets.

[0510] Furthermore, while the embodiments described above show examples where the configuration for adjusting the phase is applied to a power control device that controls a power converter 1 provided in a charging and discharging facility such as a battery system, the invention is not limited to this. For example, as shown in the 13th embodiment described later, it can also be applied to a power control device that controls a secondary excitation device provided in a charging and discharging facility such as a variable-speed pumped-storage power generation system.

[0511] [Embodiment 13] Next, we will describe the 13th embodiment. In the following, we will omit the explanation of parts that are common with the 11th embodiment and focus on the differences.

[0512] Figure 32 is a conceptual diagram showing an example of the configuration of a charging and discharging equipment having a power conversion device according to the 13th embodiment. In Figure 32, elements common to Figure 28 are denoted by the same reference numerals. Here, an example is shown where the generator motor 6 is generating power. Figure 32 also shows the situation when the grid frequency decreases in this embodiment. In this embodiment, the situation when the grid frequency is stable and the situation when the grid frequency increases can be easily inferred from the descriptions of the embodiments described above, so their illustrations and explanations are omitted.

[0513] In the aforementioned 11th embodiment, an example was shown in which a configuration for adjusting the charging and discharging power is applied to a power control device 2 that controls a power converter 1 provided in a charging and discharging facility such as a battery storage system.

[0514] In contrast, this 13th embodiment shows an example in which a configuration for adjusting the charging and discharging power is applied to a power control device 2 that controls a secondary excitation device 8 provided in a charging and discharging facility such as a pumped-storage hydroelectric power system.

[0515] The charging and discharging equipment shown in Figure 32 is, for example, the charging and discharging equipment for a variable-speed pumped-storage power generation system, and includes a generator motor 6, a pump turbine 7, a secondary excitation device 8, an excitation circuit breaker E1, and an excitation transformer E2.

[0516] The primary winding side of the generator-motor 6 is connected to the power system S via a parallel circuit breaker CB and a main transformer M. The pump-turbine 7 is mechanically connected to the generator-motor 6. The secondary excitation device 8 is connected to the secondary winding side of the generator-motor 6 and controls the generator-motor 6.

[0517] The secondary excitation device 8 is part of the components of the power converter 3. This secondary excitation device 8 has a converter 8a, a DC voltage section 8b, and an inverter 8c. One end of the converter 8a is connected to the circuit between the main transformer M and the parallel circuit breaker CB via a circuit breaker E1 and an excitation transformer E2. The DC voltage section 8b is connected between the converter 8a and the inverter 8c. The inverter 8c is connected to the secondary winding side of the generator motor 6.

[0518] The inverter 8c controls the secondary current of the generator motor 6 according to signals provided from the power control device 2 via the U-phase signal generation unit 5A, V-phase signal generation unit 5B, and W-phase signal generation unit 5C, thereby inputting (pumping) and outputting (generating) power to the power system S.

[0519] The functions, processing details, and operation of the other components are the same as in the 11th embodiment described above, so their description and illustration are omitted.

[0520] According to the 13th embodiment, even when a configuration for performing active power control using an inertia simulation control signal is applied to a power control device 2 that controls a secondary excitation device 8 provided in a charging and discharging facility such as a variable-speed pumped-storage power generation system, it becomes possible to change the amount of electricity (voltage, current, power, etc.) input and output to the generator motor 6.

[0521] This makes it possible to achieve operation similar to the inertial response in a synchronous machine (simulation of inertial response), thereby suppressing frequency fluctuations and oscillations in the electrical circuit and contributing to frequency stabilization of the electrical circuit.

[0522] In the 11th to 13th embodiments described above, an example was given in which the output of the inertia simulation control signal generation unit 15 is input to 3a or 3c. However, the inertia simulation control signal may also be input to paths related to active power control, such as the active power control command value calculation unit 202, before 3a, after 3a, before 3b, before 3c, after 3c, and the voltage command value calculation unit 2C.

[0523] Furthermore, in the parts of the path related to active power control, such as 3a, 3c, the active power control command value calculation unit 202, before 3a, after 3a, before 3b, before 3c, after 3c, and the voltage command value calculation unit 2C, the phase after phase adjustment (a value obtained by applying a function or multiplying by a coefficient as necessary) may be added, and the phase before phase adjustment (a value obtained by applying a function or multiplying by a coefficient as necessary) may be subtracted. For example, in the calculation unit 3a, the phase after phase adjustment may be added, and the phase before phase adjustment may be subtracted.

[0524] In the 11th to 13th embodiments described above, an example was given in which the inertia simulation control signal generation unit 15 is placed after the phase adjustment unit 11. However, the functions of the inertia simulation control signal generation unit 15 may be provided inside the phase adjustment unit 11, or the difference between the phase value before phase adjustment and the phase value after phase adjustment (a value obtained by applying a function or multiplying by a coefficient as necessary), which is obtained in the calculation process of the phase adjustment unit 11, may be used instead of the output signal of the inertia simulation control signal generation unit 15. Alternatively, the difference between the angular velocity before applying a function calculation (such as a first-order lag) and the angular velocity after applying a function calculation (such as a first-order lag) may be used instead of the output signal of the inertia simulation control signal generation unit 15.

[0525] In the example of the 13th embodiment described above, an example of application to a variable-speed pumped-storage power generation system was explained, but it may also be applied to a power control device that controls the secondary excitation device of a wind power charging / discharging facility equipped with a secondary excitation device or a flywheel generator-motor. It may also be applied to a power control device that controls a secondary excitation device provided in a charging / discharging facility equipped with a prime mover such as a turbine or water turbine instead of a pump-turbine, and a generator instead of a generator-motor. It may also be applied to a power control device that controls a secondary excitation device provided in a load facility equipped with a load such as a pump or fan instead of a pump-turbine, and an electric motor instead of a generator-motor.

[0526] In the 11th to 13th embodiments described above, examples were given in which the power control device 2 and the voltage signal generation unit (such as the U-phase signal generation unit 5A) are separate. However, the functions of both the power control device 2 and the voltage signal generation unit may be provided within a single control device or a single control unit. Furthermore, multiple components within the power control device 2 (such as various calculation units) may be integrated into a single component, or one or more components within the power control device 2 may be provided outside the power control device 2.

[0527] [Specific example of calculations in the main part of the power control device 2 (Part 1)] Figure 33 is a diagram illustrating a specific example (part 1) of calculations in the main part of the power control device 2 described in the first embodiment. Here, elements common to Figure 1 are denoted by the same reference numerals. Note that the specific example of calculations described here is not limited to the power control device 2 described in the first embodiment, but can also be applied to the power control device 2 described in each of the second to thirteenth embodiments by appropriately modifying them. For the second to fifth embodiments, for example, it can be applied by changing the position of the phase adjustment unit or by providing a function to change the output signal (phase) of the phase adjustment unit to a phase-adjusted signal (a signal whose amplitude is the same as the input signal, but whose phase is adjusted). For the sixth to fifth embodiments, for example, it can be applied by providing the phase adjustment unit with a function to switch functions or change coefficients using a function switching command or coefficient switching command. Embodiments 8-1 to 8-5, 9-3, and 10-3 can be applied, for example, by adding a bypass circuit outside the phase adjustment unit and providing a switch to toggle the use of the phase adjustment unit. Embodiments 11 to 13 can be applied, for example, by inputting the output signal of the phase adjustment unit 11 to the inertia simulation control signal generation unit 15 instead of inputting it to the voltage command value calculation unit 2c, and inputting the output of the phase calculation unit 2b to the phase adjustment unit 11 and the voltage command value calculation unit 2c.

[0528] The power control device 2 shown in Figure 33 includes a phase calculation unit 12A, a θα calculation unit 12B, a phase adjustment unit 11, a voltage command value calculation unit 2c, and a two-phase to three-phase conversion unit 2d.

[0529] In Figure 33, to avoid complicating the drawing, the diagram of the aforementioned system voltage measurement unit 2a is omitted, as are the other elements 2f, 2g, 3a, 3b, 3c, 3d, 3e, and 3f. The aforementioned system voltage measurement unit 2a may be provided in the phase calculation unit 12A. The phase calculation unit 12A and the θα calculation unit 12B are elements that constitute the aforementioned phase calculation unit 2b.

[0530] The phase calculation unit 12A receives the three-phase AC voltages Vu, Vv, and Vw output from the aforementioned instrument transformer VT, performs αβ conversion, and outputs the α-axis voltage Vα and β-axis voltage Vβ.

[0531] An example of an αβ conversion formula is shown below.

[0532] Vα = (2 / 3) · {Vu - (Vv + Vw) / 2} Vβ = (1 / √3)·(Vv - Vw) The θα calculation unit 12B receives the α-axis voltage Vα and the β-axis voltage Vβ as inputs, calculates the phase θα, and outputs it.

[0533] An example of a formula for calculating the phase θα is shown below.

[0534] θα = arcsin[Vβ / {√(Vα 2 +Vβ 2 )}] The phase adjustment unit 11 performs calculations to adjust the phase θα and outputs the phase after phase adjustment (adjusted phase) θαlag. In other words, the phase adjustment unit 11 generates the adjusted phase θαlag of phase θα. Specific examples of the calculations performed by the phase adjustment unit 11 will be described in detail later.

[0535] The voltage command value calculation unit 2c uses the adjusted phase θαlag to calculate and output the phase-adjusted α-axis voltage command value Vαlag and β-axis voltage command value Vβlag. Note that the converted Vα, Vβ, Vαlag, and Vβlag are sinusoidal voltages, and even if the frequency is constant, the values ​​of θα and θαlag change with time at an angular velocity corresponding to the frequency.

[0536] The two-phase to three-phase conversion unit 2d uses the phase-adjusted α-axis voltage command value Vαlag and β-axis voltage command value Vβlag to calculate and output the phase-adjusted three-phase AC voltages Vulag, Vvlag, and Vwlag.

[0537] Examples of the formulas for Vulag, Vvlag, and Vwlag are shown below. However, for the sake of ease of understanding, a formula representing a typical three-phase AC voltage that does not consider the effect of the voltage command value is used, and a comparison of the formulas for the three-phase AC voltage waveforms before and after phase adjustment is shown.

[0538] Vulag = Vup·sin(θαlag) Vvlag=Vvp·sin(θαlag-2·π / 3) Vwlag=Vwp·sin(θαlag-4·π / 3) Note that Vup, Vvp, and Vwp are the amplitude values ​​of Vu, Vv, and Vw. If the amplitude values ​​of Vu, Vv, and Vw are equal, you may use Vup instead of Vvp and Vwp, Vvp instead of Vup and Vwp, and Vwp instead of Vup and Vvp.

[0539] Here, Vu = Vup·sin(θα) Vv = Vvp·sin(θα-2·π / 3) Vw = Vwp·sin(θα-4·π / 3) Therefore, the phase difference between Vu and Vulag, Vv and Vvlag, and Vw and Vwlag is θαlag - θα.

[0540] The active power generated between the power converter 3 and the power system S can be expressed, for example, by the following formula:

[0541] P = (Vi·Vs / X)·sin(θα) Plag = (Vi·Vs / X)·sin(θαlag) Here, P: Active power without phase adjustment Plag: Active power when phase adjustment is present Vi: Output voltage of a power converter Vs: System voltage X: Impedance between power converter and grid That is the case.

[0542] Therefore, the relationships among θαlag, (θαlag - θα), P, and Plag are as follows.

[0543] When π / 2 > θαlag > 0 and (θαlag - θα) > 0, Plag (output) > P (output) When π / 2 > θαlag > 0 and (θαlag - θα) < 0, Plag (output) < P (output) When 0 > θαlag > -π / 2 and (θαlag - θα) > 0, Plag (input) < P (input) When 0 > θαlag > -π / 2 and (θαlag - θα) < 0, Plag (input) > P (input) Here, P (output): The active power output from the power conversion device when there is no phase adjustment Plag (output): The active power output from the power conversion device when there is phase adjustment P (input): The active power input to the power conversion device when there is no phase adjustment Plag (input): The active power input to the power conversion device when there is phase adjustment That is.

[0544] When the system frequency decreases while the power conversion device 3 is discharging (outputting active power), θαlag > θα, that is, (θαlag - θα) > 0, so the output of the power conversion device increases and suppresses the decrease in the system frequency.

[0545] When the system frequency increases while the power conversion device 3 is discharging (outputting active power), θαlag < θα, that is, (θαlag - θα) < 0, so the output of the power conversion device decreases and suppresses the increase in the system frequency.

[0546] When the system frequency decreases while the power conversion device 3 is charging (inputting active power), θαlag > θα, that is, (θαlag - θα) > 0, so the input of the power conversion device decreases and suppresses the decrease in the system frequency.

[0547] When the grid frequency rises while the power converter 3 is charging (receiving active power), θαlag < θα, i.e., (θαlag - θα) < 0, so the input to the power converter increases, suppressing the rise in the grid frequency.

[0548] The above example described a case where the phase θα changes in accordance with the frequency change of the power grid. However, the same effect can be obtained even when the phase θα changes in accordance with changes in power flow, etc., without changing the frequency. As the input and output of the power converter increase or decrease in accordance with the frequency and phase changes of the power grid voltage, the frequency and phase changes of the power grid are suppressed, thus simulating the inertial response of a synchronous machine.

[0549] Furthermore, by applying a function to adjust the phase θα to the calculations of the phase adjustment unit 11 in the power control device 2, the waveforms W2 and W3 in Figure 7B can be made to exhibit a desirable response to changes in the system frequency.

[0550] In the example described above, an example was given in which αβ conversion is applied to the phase calculation unit 12A. However, instead of αβ conversion, the system voltage phase may be determined by other methods (for example, PLL (phase-locked loop) calculation) and the adjusted phase may be determined.

[0551] [Specific example of calculations in the main part of the power control device 2 (part 2)] Figure 34 is a diagram illustrating a specific example (part 2) of calculations in the main part of the power control device 2 described in the first embodiment. In Figure 34, elements common to Figure 1 are denoted by the same reference numerals. Note that the specific example of calculations described here is not limited to the power control device 2 described in the first embodiment, but can also be applied to the power control device 2 described in each of the second to thirteenth embodiments by appropriately modifying it. For the second to fifth embodiments, for example, it can be applied by changing the position of the phase adjustment unit or by providing a function to change the output signal (phase) of the phase adjustment unit to a phase-adjusted signal (a signal whose amplitude is the same as the input signal, but whose phase is adjusted). For the sixth to fifth embodiments, for example, it can be applied by providing the phase adjustment unit with a function to switch functions or change coefficients using a function switching command or coefficient switching command. Embodiments 8-1 to 8-5, 9-3, and 10-3 can be applied, for example, by adding a bypass circuit outside the phase adjustment unit and providing a switch to toggle the use of the phase adjustment unit. Embodiments 11 to 13 can be applied, for example, by inputting the output signal of the phase adjustment unit 11 to the inertia simulation control signal generation unit 15 instead of inputting it to the voltage command value calculation unit 2c, and inputting the output of the phase calculation unit 2b to the phase adjustment unit 11 and the voltage command value calculation unit 2c.

[0552] The power control device 2 shown in Figure 34 includes a constant frequency signal generation unit 12C, a phase calculation unit 12D, a θd calculation unit 12E, a phase adjustment unit 11, a voltage command value calculation unit 2c, and a two-phase to three-phase conversion unit 2d.

[0553] In Figure 34, to avoid complicating the drawing, the diagram of the aforementioned system voltage measurement unit 2a is omitted, as are the diagrams of the other elements 2f, 2g, 3a, 3b, 3c, 3d, 3e, and 3f. The aforementioned system voltage measurement unit 2a may be provided in the phase calculation unit 12D. The constant frequency signal generation unit 12C, the phase calculation unit 12D, and the θd calculation unit 12E are elements that constitute the aforementioned phase calculation unit 2b.

[0554] The constant frequency signal generation unit 12C generates a constant frequency electrical signal (for example, a constant frequency signal of 50 Hz) fc.

[0555] The phase calculation unit 12D receives the three-phase AC voltages Vu, Vv, and Vw output from the aforementioned instrument transformer VT, as well as the constant frequency signal fc output from the constant frequency signal generation unit 12C, performs a dq transformation (rotational coordinate transformation), and outputs the d-axis voltage Vd and the q-axis voltage Vq.

[0556] An example of a dq conversion formula is shown below.

[0557] Vd=(2 / 3)·{cos(θc)·Vu + cos(θc-2·π / 3)·Vv + cos(θc-4·π / 3)·Vw} Vq=-(2 / 3)·{sin(θc)·Vu + sin(θc-2·π / 3)·Vv + sin(θc-4·π / 3)·Vw} Here, θc: Phase of the constant frequency signal fc (Note: Instead of the phase of the constant frequency signal fc, the average, moving average, median, etc., of the voltage phase measured by the instrument transformer VT may be used.) That is the case.

[0558] The θd calculation unit 12E receives the d-axis voltage Vd and the q-axis voltage Vq as input, calculates the phase θd, and outputs it.

[0559] An example of a formula for calculating the phase θd is shown below.

[0560] θd = arcsin[Vq / {√(Vd 2 +Vq 2 )}] The phase adjustment unit 11 performs calculations to adjust the phase θd and outputs the phase after phase adjustment (adjusted phase) θdlag. In other words, the phase adjustment unit 11 generates the adjusted phase θdlag of phase θd. Specific examples of the calculations performed by the phase adjustment unit 11 will be described in detail later.

[0561] The voltage command value calculation unit 2c uses the adjusted phase θdlag to calculate and output the phase-adjusted d-axis voltage command value Vdlag and q-axis voltage command value Vqlag. Note that if the frequencies of Vu, Vv, and Vw are the same as the constant frequency signal fc, the converted Vd and Vq will be constant values, and the values ​​of θd and θdlag will not change. If the frequencies of Vu, Vv, and Vw are different from the constant frequency signal fc, the values ​​of θd and θdlag will change at an angular velocity corresponding to the difference between the frequencies of Vu, Vv, and Vw and the frequency of the constant frequency signal fc.

[0562] The two-phase to three-phase conversion unit 2d uses the phase-adjusted d-axis voltage command value Vdlag and q-axis voltage command value Vqlag to calculate and output the phase-adjusted three-phase AC voltages Vulag, Vvlag, and Vwlag.

[0563] Examples of the formulas for Vulag, Vvlag, and Vwlag are shown below. However, for the sake of ease of understanding, a formula representing a typical three-phase AC voltage that does not consider the effect of the voltage command value is used, and a comparison of the formulas for the three-phase AC voltage waveforms before and after phase adjustment is shown.

[0564] Vulag = Vup·sin(θc+θdlag) Vvlag=Vvp·sin(θc+θdlag-2π / 3) Vwlag=Vwp·sin(θc+θdlag-4·π / 3) Note that Vup, Vvp, and Vwp are the amplitude values ​​of Vu, Vv, and Vw. If the amplitude values ​​of Vu, Vv, and Vw are equal, Vup may be used instead of Vvp and Vwp, Vvp instead of Vup and Vwp, and Vwp instead of Vup and Vvp.

[0565] Here, Vu = Vup·sin(θc+θd) Vv = Vvp·sin(θc + θd - 2·π / 3) Vw = Vwp·sin(θc + θd - 4·π / 3) Therefore, the phase difference between Vu and Vulag, Vv and Vvlag, and Vw and Vwlag is θdlag - θd.

[0566] The active power generated between the power conversion device 3 and the power system S is expressed, for example, by the following formula.

[0567] P = (Vi·Vs / X)·sin(θd) Plag = (Vi·Vs / X)·sin(θdlag) Here, P: Active power when there is no phase adjustment Plag: Active power when there is phase adjustment Vi: Output voltage of the power conversion device Vs: System voltage X: Impedance between the power conversion device and the system is.

[0568] Therefore, the relationships among θdlag, (θdlag - θd), P, and Plag are as follows.

[0569] When π / 2 > θdlag > 0 and (θdlag - θd) > 0, Plag (output) > P (output) When π / 2 > θdlag > 0 and (θdlag - θd) < 0, Plag (output) < P (output) When 0 > θdlag > -π / 2 and (θdlag - θd) > 0, Plag (input) < P (input) When 0 > θdlag > -π / 2 and (θdlag - θd) < 0, Plag (input) > P (input) Here, P (output): Active power output from the power conversion device when there is no phase adjustment Plag (output): Active power output from the power conversion device when there is phase adjustment P (input): Active power input to the power conversion device when there is no phase adjustment Plag (input): Active power input to the power conversion device when there is phase adjustment is.

[0570] When the grid frequency decreases while the power converter 3 is discharging (outputting active power), θdlag > θd, i.e., (θdlag - θd) > 0, so the output of the power converter 3 increases, suppressing the decrease in grid frequency.

[0571] When the grid frequency rises while the power converter 3 is discharging (outputting active power), θdlag < θd, i.e., (θdlag - θd) < 0, so the output of the power converter 3 decreases, suppressing the rise in grid frequency.

[0572] When the grid frequency decreases while the power converter 3 is charging (receiving active power), θdlag > θd, i.e., (θdlag - θd) > 0, so the input to the power converter 3 decreases, suppressing the decrease in the grid frequency.

[0573] When the grid frequency rises while the power converter 3 is charging (receiving active power), θdlag < θd, i.e., (θdlag - θd) < 0, so the input to the power converter 3 increases, suppressing the rise in the grid frequency.

[0574] The above example described a case where the phase θd changes in accordance with the frequency change of the power grid. However, the same effect can be obtained even when the phase changes in accordance with changes in power flow, etc., without changing the frequency. As the input and output of the power converter 3 increase or decrease in accordance with the frequency and phase changes of the power grid voltage, the frequency and phase changes of the power grid are suppressed, thus simulating the inertial response of a synchronous machine.

[0575] Furthermore, by applying a function that adjusts the phase θd to the calculations of the phase adjustment unit 11 in the power control device 2, the waveforms W2 and W3 in Figure 7B can be made to show a desirable response to changes in the system frequency.

[0576] In the example described above, an example was given in which dq conversion is applied to the phase calculation unit 12A. However, instead of dq conversion, the system voltage phase may be determined by other methods (for example, PLL (phase-locked loop) calculation) and the adjusted phase may be determined.

[0577] [Specific examples of calculations in the phase adjustment unit 11 1-1, 1-2] (Specific example 1-1) Figure 35A is a diagram illustrating specific example 1-1 of calculations applicable to the phase adjustment unit 11 in Figure 33 or the phase adjustment unit 11 in Figure 34, the phase adjustment units 21, 32, 41-43 or 52 of the second to thirteenth embodiments described above, or the function calculation units F1, F2 or F20 in Figures 18F, 20F or 22B.

[0578] The phase adjustment unit / function calculation unit F0 shown in Figure 35A includes an angular velocity calculation unit 13A and a phase adjustment function processing unit 13B, and performs the following calculations.

[0579] • When the input in Figure 35A is θα The angular velocity calculation unit 13A receives a phase θα as input, calculates the angular velocity ωα for phase θα, and outputs it.

[0580] The phase adjustment function processing unit 13B calculates and outputs the angular velocity ωα of phase θα output from the angular velocity calculation unit 13A, and the phase θαlag which is adjusted using a function that takes phase θα as input and delays the change in angular velocity ωα.

[0581] • When the input in Figure 35A is θd The angular velocity calculation unit 13A receives a phase θd as input, calculates the angular velocity ωd for phase θd, and outputs it.

[0582] The phase adjustment function processing unit 13B calculates and outputs the phase θdlag, which is adjusted using a function that takes the phase θd as input and delays the change in the angular velocity ωd, as output from the angular velocity calculation unit 13A.

[0583] As shown in the example in Figure 35A, by applying a function that delays the change in the angular velocity ωα of phase θα or the angular velocity ωd of phase θd to the calculation processing performed in the phase adjustment unit 11, the waveforms W2 and W3 in Figure 7B can be made to show a desirable response to changes in the system frequency.

[0584] (Specific examples 1-2) Figure 35B is a diagram illustrating specific examples 1-2 of operations applicable to the phase adjustment unit 11 in Figure 33 or the phase adjustment unit 11 in Figure 34, the phase adjustment units 21, 32, 41-43 or 52 of the second to thirteenth embodiments described above, or the function operation units F1, F2 or F20 in Figures 18F, 20F or 22B.

[0585] The phase adjustment unit / function calculation unit F0 shown in Figure 35B includes a phase change amount calculation unit 13C and a phase adjustment function processing unit 13D, and performs the following calculations.

[0586] • When the input in Figure 35B is θα The phase change calculation unit 13C receives a phase θα as input, calculates the change in phase θα Δθα, and outputs it.

[0587] The phase adjustment function processing unit 13D takes the change amount Δθα output from the phase change amount calculation unit 13C and the phase θα as input, and calculates and outputs the phase θαlag, which is adjusted using a function that delays the change amount Δθα.

[0588] • When the input in Figure 35B is θd The phase change calculation unit 13C receives the phase θd as input, calculates the change in phase θd Δθd, and outputs it.

[0589] The phase adjustment function processing unit 13D takes the change amount Δθd output from the phase change amount calculation unit 13C and the phase θd as input, and calculates and outputs the phase θdlag, which is adjusted using a function that delays the change amount Δθd.

[0590] As shown in the example in Figure 35B, by applying a function that delays the change in phase θα Δθα or the change in phase θd Δθd in the calculation processing performed in the phase adjustment unit 11, the waveforms W2 and W3 in Figure 7B can be made to show a desirable response to changes in the system frequency.

[0591] [Specific examples of calculations in the phase adjustment unit 11 2-1, 2-2] (Specific example 2-1) Figure 36A is a diagram illustrating specific example 2-1 of calculations applicable to the phase adjustment unit 11 in Figure 33 or the phase adjustment unit 11 in Figure 34, the phase adjustment units 21, 32, 41-43 or 52 of the second to thirteenth embodiments described above, or the function calculation units F1, F2 or F20 in Figures 18F, 20F or 22B.

[0592] The phase adjustment unit / function calculation unit F0 shown in Figure 36A includes an angular velocity calculation unit 13A, a first-order lag calculation unit 13E, and a Δt multiplication unit 13F, and performs the following calculations.

[0593] • When the input in Figure 36A is θα The angular velocity calculation unit 13A receives a phase θα as input, calculates the angular velocity ωα for phase θα, and outputs it.

[0594] The first-order lag calculation unit 13E receives the angular velocity ωα of phase θα output from the angular velocity calculation unit 13A, and calculates and outputs a phase adjustment signal ωαdif1 using a calculation that includes a function to delay the angular velocity ωα by one order.

[0595] The Δt multiplication unit 13F receives the signal ωαdif1 output from the first-order lag calculation unit 13E, multiplies ωαdif1 by the step time Δt to convert the angular velocity into a phase change, and outputs the result. The calculation unit 130 calculates the value obtained by adding the output of the Δt multiplication unit 13F and the phase θα, and outputs the adjusted phase θαlag to the outside of the phase adjustment unit 11.

[0596] In the example above, we described an example where ωαdif1 is multiplied by Δt to convert the angular velocity into a phase change. However, if dimensionless quantities such as the pu value are used for various variables, the Δt multiplication part 13F can be omitted.

[0597] • When the input in Figure 36A is θd The angular velocity calculation unit 13A receives a phase θd as input, calculates the angular velocity ωd for phase θd, and outputs it.

[0598] The first-order lag calculation unit 13E receives the angular velocity ωd of phase θd output from the angular velocity calculation unit 13A, and calculates and outputs a phase adjustment signal ωddif1 using a calculation that includes a function to lag the angular velocity ωd by one order.

[0599] The Δt multiplication unit 13F receives the signal ωddif1 output from the first-order lag calculation unit 13E, multiplies ωddif1 by the step time Δt to convert the angular velocity into a phase change, and outputs the result. The calculation unit 130 calculates the sum of the output of the Δt multiplication unit 13F and the phase θd, and outputs the adjusted phase θdlag to the outside of the phase adjustment unit 11.

[0600] In the example above, we explained how to convert angular velocity into a phase change by multiplying ωddif1 by Δt. However, you can also use dimensionless quantities such as pu values ​​for various variables and omit the Δt multiplication part 13F.

[0601] As shown in the example in Figure 36A, by applying a calculation that includes a function that lags the angular velocity ωα of phase θα or the angular velocity ωd of phase θd by one order to the calculat...

Claims

1. A power control device that controls a power converter connected to an AC electrical circuit, An electrical quantity measuring means for measuring the amount of electricity in the aforementioned electrical circuit, A phase calculation means for determining the phase of the electric quantity measured by the electric quantity measuring means, A phase adjustment means for adjusting the phase of the electric quantity determined by the phase calculation means, A command value calculation means for determining a control command value for the power converter based on the phase adjusted by the phase adjustment means, It is equipped with, The phase adjustment means is By using a first-order lag calculation or a calculation other than the first-order lag calculation to produce a phase lag in the phase adjustment means, If the input signal of the phase adjustment means continues to change, the amount of change in the output signal of the phase adjustment means shall be set to be smaller than the amount of change in the input signal. Power control device.

2. A power control device that controls a power converter connected to an AC electrical circuit, An electrical quantity measuring means for measuring the amount of electricity in the aforementioned electrical circuit, A phase calculation means for determining the phase of the electric quantity measured by the electric quantity measuring means, A command value calculation means for determining a control command value for the power converter based on the phase of the electric quantity obtained by the phase calculation means, A phase adjustment means for adjusting the phase of the control command value obtained by the command value calculation means, AC waveform generation means generates an AC waveform of the control command value by converting the phase of the control command value, whose phase has been adjusted by the phase adjustment means, into a two-phase to three-phase. It is equipped with, The phase adjustment means is By using a first-order lag calculation or a calculation other than the first-order lag calculation to produce a phase lag in the phase adjustment means, If the input signal of the phase adjustment means continues to change, the amount of change in the output signal of the phase adjustment means shall be set to be smaller than the amount of change in the input signal. Power control device.

3. A power control device that controls a power converter connected to an AC electrical circuit, An electrical quantity measuring means for measuring the amount of electricity in the aforementioned electrical circuit, A phase measuring means that converts the amount of electricity measured by the aforementioned electrical quantity measuring means into a three-phase to two-phase and then determines the phase of said electrical quantity, A phase adjustment means for adjusting the phase of the electric quantity determined by the phase measuring means, A phase calculation means for determining the phase of an electric quantity from an electric quantity whose phase has been adjusted by the phase adjustment means, A command value calculation means for determining a control command value for the power converter based on the phase of the electric quantity obtained by the phase calculation means, AC waveform generation means generates an AC waveform of the control command value obtained by the command value calculation means by performing a two-phase to three-phase conversion. It is equipped with, The phase adjustment means is By using a first-order lag calculation or a calculation other than the first-order lag calculation to produce a phase lag in the phase adjustment means, If the input signal of the phase adjustment means continues to change, the amount of change in the output signal of the phase adjustment means shall be set to be smaller than the amount of change in the input signal. Power control device.

4. A power control device that controls a power converter connected to an AC electrical circuit, An electrical quantity measuring means for measuring the amount of electricity in the aforementioned electrical circuit, A phase calculation means for determining the phase of the electric quantity measured by the electric quantity measuring means, A command value calculation means for determining a control command value for the power converter based on the phase of the electric quantity obtained by the phase calculation means, AC waveform generation means that generates an AC waveform of the control command value obtained by the command value calculation means by performing a two-phase to three-phase conversion of the control command value, Phase adjustment means for adjusting the phase of the command value of the AC waveform converted by the AC waveform generation means. It is equipped with, The phase adjustment means is By using a first-order lag calculation or a calculation other than the first-order lag calculation to produce a phase lag in the phase adjustment means, If the input signal of the phase adjustment means continues to change, the amount of change in the output signal of the phase adjustment means shall be set to be smaller than the amount of change in the input signal. Power control device.

5. A power control device that controls a power converter connected to an AC electrical circuit, An electrical quantity measuring means for measuring the amount of electricity in the aforementioned electrical circuit, A first phase calculation means for determining the phase of the electric quantity measured by the electric quantity measuring means, A phase adjustment means for adjusting the phase of the electric quantity determined by the first phase calculation means, AC waveform generation means for generating an AC waveform of an electric quantity whose phase has been adjusted by the phase adjustment means, A second phase calculation means for determining the phase of the AC waveform of the electric quantity generated by the AC waveform generation means, A command value calculation means that calculates a control command value for the power converter based on the phase of the electric quantity obtained by the second phase calculation means. It is equipped with, The phase adjustment means is By using a first-order lag calculation or a calculation other than the first-order lag calculation to produce a phase lag in the phase adjustment means, If the input signal of the phase adjustment means continues to change, the amount of change in the output signal of the phase adjustment means shall be set to be smaller than the amount of change in the input signal. Power control device.

6. A power control device that controls a power converter connected to an AC electrical circuit, An electrical quantity measuring means for measuring the amount of electricity in the aforementioned electrical circuit, A command value calculation means for determining a control command value for the power converter based on the amount of electricity measured by the amount of electricity measuring means, A phase calculation means for determining the phase of the electric quantity measured by the electric quantity measuring means, A phase adjustment means for adjusting the phase of the electric quantity determined by the phase calculation means, A control signal generation means that generates a control signal using a signal indicating the difference before and after the phase adjustment adjusted by the phase adjustment means, It is equipped with, The phase adjustment means is By using a first-order lag calculation or a calculation other than the first-order lag calculation to produce a phase lag in the phase adjustment means, If the input signal of the phase adjustment means continues to change, the amount of change in the output signal of the phase adjustment means shall be set to be smaller than the amount of change in the input signal. The signal generated by the control signal generation means is used to control the active power command value given to the power control device, the voltage command value given to the command value calculation means, or the current command value given to the command value calculation means. Power control device.

7. A power control device for controlling a power converter of a rotating machine connected to an AC electrical circuit, An electrical quantity measuring means for measuring the amount of electricity in the aforementioned electrical circuit, A command value calculation means for determining a control command value for the power converter based on the amount of electricity measured by the amount of electricity measuring means, A phase calculation means for determining the phase of the electric quantity measured by the electric quantity measuring means, A phase adjustment means for adjusting the phase of the electric quantity determined by the phase calculation means, A control signal generation means that generates a control signal using a signal indicating the difference before and after the phase adjustment adjusted by the phase adjustment means, It is equipped with, The phase adjustment means is By using a first-order lag calculation or a calculation other than the first-order lag calculation to produce a phase lag in the phase adjustment means, If the input signal of the phase adjustment means continues to change, the amount of change in the output signal of the phase adjustment means shall be set to be smaller than the amount of change in the input signal. The signal generated by the control signal generation means is used to control the active power command value given to the power control device, the voltage command value given to the command value calculation means, or the current command value given to the command value calculation means. Power control device.

8. The phase adjustment means is It has a plurality of functions that make it possible to change the degree of the phase adjustment, In response to a command to switch functions, a specified function from among the plurality of functions is used for adjusting the phase. The power control device according to any one of claims 1 to 7.

9. The phase adjustment means is The function has the ability to change the degree of phase adjustment according to the value of the coefficient, In response to a command to change the coefficient, the specified coefficient value is used for adjusting the phase. The power control device according to any one of claims 1 to 7.

10. The system further comprises a switching means that enables switching between a first path through which a signal indicating the amount of electricity in the electrical circuit passes via the phase adjustment means, and a second path that bypasses the phase adjustment means. The aforementioned switching means is In response to a command to switch routes, the specified route among the first route and the second route is activated. The power control device according to any one of claims 1 to 7.

11. A power control device according to any one of claims 1 to 7, An electrical quantity change calculation means for determining the amount of change or rate of change of the electrical quantity obtained by measuring the electrical quantity of the aforementioned electrical circuit, A comparison means that outputs information indicating whether the amount of change or rate of change of the electrical quantity determined by the electrical quantity change calculation means is greater than or equal to a predetermined reference value or greater than or equal to a predetermined reference value, A command means that changes the degree of phase adjustment according to the information output from the comparison means. A power conversion device equipped with the following.

12. A power control device according to any one of claims 1 to 7, A comparison means that outputs information indicating whether the value of the electrical quantity obtained by measuring the electrical quantity of the aforementioned electrical circuit is equal to or greater than a predetermined standard value, or equal to or less than a predetermined standard value, A command means that changes the degree of phase adjustment according to the information output from the comparison means. A power conversion device equipped with the following.

13. A power control device according to any one of claims 1 to 7, A determination means that outputs information indicating whether the value of the first electrical quantity obtained by measuring the first electrical quantity of the electrical circuit, or the amount or rate of change of that value, is greater than or greater than a predetermined standard value or greater than or less than a predetermined standard value, and whether the value of the second electrical quantity obtained by measuring the second electrical quantity of the electrical circuit, or the amount or rate of change of that value, is greater than or greater than a predetermined standard value or greater than or less than a predetermined standard value. A command means that changes the degree of phase adjustment according to the information output from the determination means. A power conversion device equipped with the following.

14. A power control method applied to a power control device that controls a power converter connected to an AC electrical circuit, A process for measuring the amount of electricity in the aforementioned electrical circuit, A phase calculation step for determining the phase of the electric quantity measured in the electric quantity measurement step, A phase adjustment step for adjusting the phase of the electric quantity obtained in the phase calculation step, A command value calculation step that determines a control command value for the power converter based on the phase adjusted in the phase adjustment step. Includes, In the aforementioned phase adjustment process, By using a first-order lag calculation or a calculation other than the first-order lag calculation to generate a phase lag in the phase adjustment process, If the input signal continues to change during the phase adjustment process, the amount of change in the output signal during the phase adjustment process shall be set to be smaller than the amount of change in the input signal. Power control method.

15. A power control method applied to a power control device that controls a power converter connected to an AC electrical circuit, A process for measuring the amount of electricity in the aforementioned electrical circuit, A phase calculation step for determining the phase of the electric quantity measured in the electric quantity measurement step, A command value calculation step, which determines a control command value for the power converter based on the phase of the electric quantity obtained in the phase calculation step, A phase adjustment step for adjusting the phase of the control command value obtained in the command value calculation step, AC waveform generation step generates an AC waveform of the control command value by converting the control command value, whose phase change rate has been adjusted in the phase adjustment step, into a two-phase to three-phase converter. Includes, In the aforementioned phase adjustment process, By using a first-order lag calculation or a calculation other than the first-order lag calculation to generate a phase lag in the phase adjustment process, If the input signal continues to change during the phase adjustment process, the amount of change in the output signal during the phase adjustment process shall be set to be smaller than the amount of change in the input signal. Power control method.

16. A power control method applied to a power control device that controls a power converter connected to an AC electrical circuit, A process for measuring the amount of electricity in the aforementioned electrical circuit, A phase measurement step for determining the phase of the electric quantity measured in the electric quantity measurement step, A phase adjustment step for adjusting the phase of the electric quantity obtained in the phase measurement step, A phase calculation step to determine the phase of an electric quantity from the electric quantity whose phase has been adjusted in the phase adjustment step, A command value calculation step, which determines a control command value for the power converter based on the phase of the electric quantity obtained in the phase calculation step, AC waveform generation step generates an AC waveform of the control command value obtained in the command value calculation step by performing a two-phase to three-phase conversion on the control command value obtained in the command value calculation step. Includes, In the aforementioned phase adjustment process, By using a first-order lag calculation or a calculation other than the first-order lag calculation to generate a phase lag in the phase adjustment process, If the input signal continues to change during the phase adjustment process, the amount of change in the output signal during the phase adjustment process shall be set to be smaller than the amount of change in the input signal. Power control method.

17. A power control method applied to a power control device that controls a power converter connected to an AC electrical circuit, A process for measuring the amount of electricity in the aforementioned electrical circuit, A phase calculation step for determining the phase of the electric quantity measured in the electric quantity measurement step, A command value calculation step, which determines a control command value for the power converter based on the phase of the electric quantity obtained in the phase calculation step, An AC waveform generation step generates an AC waveform of the control command value obtained in the command value calculation step by performing a two-phase to three-phase conversion on the control command value, A phase adjustment step for adjusting the phase of the command value of the AC waveform converted in the AC waveform generation step, Includes, In the aforementioned phase adjustment process, By using a first-order lag calculation or a calculation other than the first-order lag calculation to generate a phase lag in the phase adjustment process, If the input signal continues to change during the phase adjustment process, the amount of change in the output signal during the phase adjustment process shall be set to be smaller than the amount of change in the input signal. Power control method.

18. A power control method applied to a power control device that controls a power converter connected to an AC electrical circuit, A process for measuring the amount of electricity in the aforementioned electrical circuit, A first phase calculation step for determining the phase of the electric quantity measured in the electric quantity measurement step, A phase adjustment step for adjusting the phase of the electric quantity obtained in the first phase calculation step, An AC waveform generation step that generates an AC waveform of the electric quantity whose phase has been adjusted in the phase adjustment step, A second phase calculation step for determining the phase of the AC waveform of the electric quantity generated in the AC waveform generation step, A command value calculation step that determines a control command value for the power converter based on the phase of the electric quantity obtained in the second phase calculation step, Includes, In the aforementioned phase adjustment process, By using a first-order lag calculation or a calculation other than the first-order lag calculation to generate a phase lag in the phase adjustment process, If the input signal continues to change during the phase adjustment process, the amount of change in the output signal during the phase adjustment process shall be set to be smaller than the amount of change in the input signal. Power control method.

19. A power control method applied to a power control device that controls a power converter connected to an AC electrical circuit, A process for measuring the amount of electricity in the aforementioned electrical circuit, A command value calculation step which determines a control command value for the power converter based on the amount of electricity measured in the amount of electricity measurement step, A phase calculation step for determining the phase of the electric quantity measured in the electric quantity measurement step, A phase adjustment step for adjusting the phase of the electric quantity obtained in the phase calculation step, A control signal generation step that generates a control signal using a signal indicating the difference before and after the phase adjustment performed in the phase adjustment step, Includes, In the aforementioned phase adjustment process, By using a first-order lag calculation or a calculation other than the first-order lag calculation to generate a phase lag in the phase adjustment process, If the input signal continues to change during the phase adjustment process, the amount of change in the output signal during the phase adjustment process shall be set to be smaller than the amount of change in the input signal. The signal generated in the control signal generation step is used to control the active power command value given to the power control device, the voltage command value given to the command value calculation step, or the current command value given to the command value calculation step. Power control method.

20. A power control method applied to a power control device that controls a power converter for a rotating machine connected to an AC electrical circuit, A process for measuring the amount of electricity in the aforementioned electrical circuit, A command value calculation step which determines a control command value for the power converter based on the amount of electricity measured in the amount of electricity measurement step, A phase calculation step for determining the phase of the electric quantity measured in the electric quantity measurement step, A phase adjustment step for adjusting the phase of the electric quantity obtained in the phase calculation step, A control signal generation step that generates a control signal using a signal indicating the difference before and after the phase adjustment performed in the phase adjustment step, Includes, In the aforementioned phase adjustment process, By using a first-order lag calculation or a calculation other than the first-order lag calculation to generate a phase lag in the phase adjustment process, If the input signal continues to change during the phase adjustment process, the amount of change in the output signal during the phase adjustment process shall be set to be smaller than the amount of change in the input signal. A power control method in which the signal generated in the control signal generation step is used to control the active power command value given to the power control device, to control the voltage command value given to the command value calculation step, or to control the current command value given to the command value calculation step.

21. The aforementioned phase adjustment step is It has a plurality of functions that make it possible to change the degree of the phase adjustment, The process includes using a specified function from among the plurality of functions for adjusting the phase in response to a command to switch functions, The power control method according to any one of claims 14 to 20.

22. The aforementioned phase adjustment step is The function has the ability to change the degree of phase adjustment according to the value of the coefficient, The process includes a step of using a specified coefficient value for adjusting the phase in response to a command to change the coefficient, The power control method according to any one of claims 14 to 20.

23. The system further includes a switching step that enables switching between a first path that passes through the phase adjustment step and a second path that bypasses the phase adjustment step for a signal indicating the amount of electricity in the electrical circuit. The aforementioned switching process is, The process includes a step of enabling a designated route from among the first route and the second route in response to a route switching command. The power control method according to any one of claims 14 to 20.

24. A process for calculating changes in electrical quantities, which involves measuring the amount of electricity in the aforementioned electrical circuit and determining the amount of change or rate of change of said electrical quantity, A comparison step that outputs information indicating whether the amount of change or rate of change of the electrical quantity obtained in the electrical quantity change calculation step is greater than or equal to a predetermined reference value or greater than or equal to a predetermined reference value, A command step which changes the degree of phase adjustment according to the information output from the comparison step, A power control method according to any one of claims 14 to 20, further comprising:

25. A comparison step that outputs information showing the relationship between the magnitude of the value of the electrical quantity obtained by measuring the electrical quantity of the aforementioned electrical circuit and a predetermined reference value, A command step which changes the degree of phase adjustment according to the information output from the comparison step, A power control method according to any one of claims 14 to 20, further comprising:

26. A determination step that outputs information indicating whether the value of the first electrical quantity obtained by measuring the first electrical quantity of the electrical circuit, or the amount or rate of change of that value, is greater than or greater than a predetermined standard value, or less than or equal to a predetermined standard value, and whether the value of the second electrical quantity obtained by measuring the second electrical quantity of the electrical circuit, or the amount or rate of change of that value, is greater than or greater than a predetermined standard value, or less than or equal to a predetermined standard value. A command step which changes the degree of phase adjustment according to the information output from the determination step, A power control method according to any one of claims 14 to 20, further comprising:

27. The phase calculation means performs an αβ transform or a dq transform, The phase adjustment means generates an adjusted phase by adjusting the phase of the electric quantity after αβ conversion or dq conversion. The power control device according to any one of claims 1 to 7.

28. The phase adjustment means is The adjusted phase is generated by performing calculations using the angular velocity or change in the phase of the electric quantity after αβ transformation or dq transformation. The power control device according to claim 27.

29. A power control device for controlling a power converter connected to an AC electrical circuit, An electrical quantity measuring means for measuring the amount of electricity in the aforementioned electrical circuit, A phase calculation means for determining the phase of the electric quantity measured by the electric quantity measuring means, A phase adjustment means for adjusting the phase of the electric quantity determined by the phase calculation means, A command value calculation means for determining a control command value for the power converter based on the phase adjusted by the phase adjustment means, It is equipped with, The phase calculation means performs an αβ transform or a dq transform, The phase adjustment means generates an adjusted phase by performing calculations using at least one of a first-order lag and a second-order lag on the angular velocity or change in the phase of the electric quantity after αβ conversion or dq conversion. Power control device.

30. A power control device for controlling a power converter connected to an AC electrical circuit, An electrical quantity measuring means for measuring the amount of electricity in the aforementioned electrical circuit, A phase calculation means for determining the phase of the electric quantity measured by the electric quantity measuring means, A command value calculation means for determining a control command value for the power converter based on the phase of the electric quantity obtained by the phase calculation means, A phase adjustment means for adjusting the phase of the control command value obtained by the command value calculation means, AC waveform generation means generates an AC waveform of the control command value by converting the phase of the control command value, whose phase has been adjusted by the phase adjustment means, into a two-phase to three-phase. It is equipped with, The phase calculation means performs an αβ transform or a dq transform, The phase adjustment means generates an adjusted phase by performing calculations using at least one of a first-order lag and a second-order lag on the angular velocity or change in the phase of the electric quantity after αβ conversion or dq conversion. Power control device.

31. A power control device for controlling a power converter connected to an AC electrical circuit, An electrical quantity measuring means for measuring the amount of electricity in the aforementioned electrical circuit, A phase measuring means that converts the electric quantity measured by the electric quantity measuring means into a three-phase to two-phase and then determines the phase of the electric quantity, A phase adjustment means for adjusting the phase of the electric quantity determined by the phase measuring means, A phase calculation means for determining the phase of an electric quantity from an electric quantity whose phase has been adjusted by the phase adjustment means, A command value calculation means for determining a control command value for the power converter based on the phase of the electric quantity obtained by the phase calculation means, AC waveform generation means generates an AC waveform of the control command value obtained by the command value calculation means by performing a two-phase to three-phase conversion. It is equipped with, The phase calculation means performs an αβ transform or a dq transform, The phase adjustment means generates an adjusted phase by performing calculations using at least one of a first-order lag and a second-order lag on the angular velocity or change in the phase of the electric quantity after αβ conversion or dq conversion. Power control device.

32. A power control device for controlling a power converter connected to an AC electrical circuit, An electrical quantity measuring means for measuring the amount of electricity in the aforementioned electrical circuit, A phase calculation means for determining the phase of the electric quantity measured by the electric quantity measuring means, A command value calculation means for determining a control command value for the power converter based on the phase of the electric quantity obtained by the phase calculation means, AC waveform generation means that generates an AC waveform of the control command value obtained by the command value calculation means by performing a two-phase to three-phase conversion of the control command value, Phase adjustment means for adjusting the phase of the command value of the AC waveform converted by the AC waveform generation means. It is equipped with, The phase calculation means performs an αβ transform or a dq transform, The phase adjustment means generates an adjusted phase by performing calculations using at least one of a first-order lag and a second-order lag on the angular velocity or change in the phase of the electric quantity after αβ conversion or dq conversion. Power control device.

33. A power control device for controlling a power converter connected to an AC electrical circuit, An electrical quantity measuring means for measuring the amount of electricity in the aforementioned electrical circuit, A first phase calculation means for determining the phase of the electric quantity measured by the electric quantity measuring means, A phase adjustment means for adjusting the phase of the electric quantity determined by the first phase calculation means, AC waveform generation means for generating an AC waveform of an electric quantity whose phase has been adjusted by the phase adjustment means, A second phase calculation means for determining the phase of the AC waveform of the electric quantity generated by the AC waveform generation means, A command value calculation means that calculates a control command value for the power converter based on the phase of the electric quantity obtained by the second phase calculation means. It is equipped with, The phase calculation means performs an αβ transform or a dq transform, The phase adjustment means generates an adjusted phase by performing calculations using at least one of a first-order lag and a second-order lag on the angular velocity or change in the phase of the electric quantity after αβ conversion or dq conversion. Power control device.

34. A power control device for controlling a power converter connected to an AC electrical circuit, An electrical quantity measuring means for measuring the amount of electricity in the aforementioned electrical circuit, A command value calculation means for determining a control command value for the power converter based on the amount of electricity measured by the amount of electricity measuring means, A phase calculation means for determining the phase of the electric quantity measured by the electric quantity measuring means, A phase adjustment means for adjusting the phase of the electric quantity determined by the phase calculation means, A control signal generation means that generates a control signal using a signal indicating the difference before and after the phase adjustment adjusted by the phase adjustment means, It is equipped with, The phase calculation means performs an αβ transform or a dq transform, The phase adjustment means generates an adjusted phase by performing calculations using at least one of a first-order lag and a second-order lag on the angular velocity or change in the phase of the electric quantity after αβ conversion or dq conversion, thereby adjusting the phase of the electric quantity after αβ conversion or dq conversion. The signal generated by the control signal generation means is used to control the active power command value given to the power control device, the voltage command value given to the command value calculation means, or the current command value given to the command value calculation means. Power control device.

35. A power control device for controlling a power converter of a rotating machine connected to an AC electrical circuit, An electrical quantity measuring means for measuring the amount of electricity in the aforementioned electrical circuit, A command value calculation means for determining a control command value for the power converter based on the amount of electricity measured by the amount of electricity measuring means, A phase calculation means for determining the phase of the electric quantity measured by the electric quantity measuring means, A phase adjustment means for adjusting the phase of the electric quantity determined by the phase calculation means, A control signal generation means that generates a control signal using a signal indicating the difference before and after the phase adjustment adjusted by the phase adjustment means, It is equipped with, The phase calculation means performs an αβ transform or a dq transform, The phase adjustment means generates an adjusted phase by performing calculations using at least one of a first-order lag and a second-order lag on the angular velocity or change in the phase of the electric quantity after αβ conversion or dq conversion, thereby adjusting the phase of the electric quantity after αβ conversion or dq conversion. The signal generated by the control signal generation means is used to control the active power command value given to the power control device, the voltage command value given to the command value calculation means, or the current command value given to the command value calculation means. Power control device.

36. A power control device for controlling a power converter connected to an AC electrical circuit, An electrical quantity measuring means for measuring the amount of electricity in the aforementioned electrical circuit, A phase calculation means for determining the phase of the electric quantity measured by the electric quantity measuring means, A phase adjustment means for adjusting the phase of the electric quantity determined by the phase calculation means, A command value calculation means for determining a control command value for the power converter based on the phase adjusted by the phase adjustment means, It is equipped with, The phase calculation means performs an αβ transform or a dq transform, The phase adjustment means generates an adjusted phase by adjusting the phase of the electric quantity after αβ transformation or dq transformation using phase-synchronization calculation. The adjusted phase can be adjusted by changing the values ​​of the time constant and coefficients used in the phase synchronization calculation. Power control device.

37. A power control device for controlling a power converter connected to an AC electrical circuit, An electrical quantity measuring means for measuring the amount of electricity in the aforementioned electrical circuit, A phase calculation means for determining the phase of the electric quantity measured by the electric quantity measuring means, A command value calculation means for determining a control command value for the power converter based on the phase of the electric quantity obtained by the phase calculation means, A phase adjustment means for adjusting the phase of the control command value obtained by the command value calculation means, AC waveform generation means generates an AC waveform of the control command value by converting the phase of the control command value, whose phase has been adjusted by the phase adjustment means, into a two-phase to three-phase. It is equipped with, The phase calculation means performs an αβ transform or a dq transform, The phase adjustment means generates an adjusted phase by adjusting the phase of the electric quantity after αβ transformation or dq transformation using phase-synchronization calculation. The adjusted phase can be adjusted by changing the values ​​of the time constant and coefficients used in the phase synchronization calculation. Power control device.

38. A power control device for controlling a power converter connected to an AC electrical circuit, An electrical quantity measuring means for measuring the amount of electricity in the aforementioned electrical circuit, A phase measuring means that converts the amount of electricity measured by the aforementioned electrical quantity measuring means into a three-phase to two-phase and then determines the phase of said electrical quantity, A phase adjustment means for adjusting the phase of the electric quantity determined by the phase measuring means, A phase calculation means for determining the phase of an electric quantity from an electric quantity whose phase has been adjusted by the phase adjustment means, A command value calculation means for determining a control command value for the power converter based on the phase of the electric quantity obtained by the phase calculation means, AC waveform generation means generates an AC waveform of the control command value obtained by the command value calculation means by performing a two-phase to three-phase conversion. It is equipped with, The phase calculation means performs an αβ transform or a dq transform, The phase adjustment means generates an adjusted phase by adjusting the phase of the electric quantity after αβ transformation or dq transformation using phase-synchronization calculation. The adjusted phase can be adjusted by changing the values ​​of the time constant and coefficients used in the phase synchronization calculation. Power control device.

39. A power control device for controlling a power converter connected to an AC electrical circuit, An electrical quantity measuring means for measuring the amount of electricity in the aforementioned electrical circuit, A phase calculation means for determining the phase of the electric quantity measured by the electric quantity measuring means, A command value calculation means for determining a control command value for the power converter based on the phase of the electric quantity obtained by the phase calculation means, AC waveform generation means that generates an AC waveform of the control command value obtained by the command value calculation means by performing a two-phase to three-phase conversion of the control command value, Phase adjustment means for adjusting the phase of the command value of the AC waveform converted by the AC waveform generation means. It is equipped with, The phase calculation means performs an αβ transform or a dq transform, The phase adjustment means generates an adjusted phase by adjusting the phase of the electric quantity after αβ transformation or dq transformation using phase-synchronization calculation. The adjusted phase can be adjusted by changing the values ​​of the time constant and coefficients used in the phase synchronization calculation. Power control device.

40. A power control device for controlling a power converter connected to an AC electrical circuit, An electrical quantity measuring means for measuring the amount of electricity in the aforementioned electrical circuit, A first phase calculation means for determining the phase of the electric quantity measured by the electric quantity measuring means, A phase adjustment means for adjusting the phase of the electric quantity determined by the first phase calculation means, AC waveform generation means for generating an AC waveform of an electric quantity whose phase has been adjusted by the phase adjustment means, A second phase calculation means for determining the phase of the AC waveform of the electric quantity generated by the AC waveform generation means, A command value calculation means that calculates a control command value for the power converter based on the phase of the electric quantity obtained by the second phase calculation means. It is equipped with, The phase calculation means performs an αβ transform or a dq transform, The phase adjustment means generates an adjusted phase by adjusting the phase of the electric quantity after αβ transformation or dq transformation using phase-synchronization calculation. The adjusted phase can be adjusted by changing the values ​​of the time constant and coefficients used in the phase synchronization calculation. Power control device.

41. A power control device for controlling a power converter connected to an AC electrical circuit, An electrical quantity measuring means for measuring the amount of electricity in the aforementioned electrical circuit, A command value calculation means for determining a control command value for the power converter based on the amount of electricity measured by the amount of electricity measuring means, A phase calculation means for determining the phase of the electric quantity measured by the electric quantity measuring means, A phase adjustment means for adjusting the phase of the electric quantity determined by the phase calculation means, A control signal generation means that generates a control signal using a signal indicating the difference before and after the phase adjustment adjusted by the phase adjustment means, It is equipped with, The phase calculation means performs an αβ transform or a dq transform, The phase adjustment means generates an adjusted phase by adjusting the phase of the electric quantity after αβ transformation or dq transformation using phase-synchronization calculation. The adjusted phase can be adjusted by changing the values ​​of the time constant and coefficients used in the phase synchronization calculation. The signal generated by the control signal generation means is used to control the active power command value given to the power control device, the voltage command value given to the command value calculation means, or the current command value given to the command value calculation means. Power control device.

42. A power control device for controlling a power converter of a rotating machine connected to an AC electrical circuit, An electrical quantity measuring means for measuring the amount of electricity in the aforementioned electrical circuit, A command value calculation means for determining a control command value for the power converter based on the amount of electricity measured by the amount of electricity measuring means, A phase calculation means for determining the phase of the electric quantity measured by the electric quantity measuring means, A phase adjustment means for adjusting the phase of the electric quantity determined by the phase calculation means, A control signal generation means that generates a control signal using a signal indicating the difference before and after the phase adjustment adjusted by the phase adjustment means, It is equipped with, The phase calculation means performs an αβ transform or a dq transform, The phase adjustment means generates an adjusted phase by adjusting the phase of the electric quantity after αβ transformation or dq transformation using phase-synchronization calculation. The adjusted phase can be adjusted by changing the values ​​of the time constant and coefficients used in the phase synchronization calculation. The signal generated by the control signal generation means is used to control the active power command value given to the power control device, the voltage command value given to the command value calculation means, or the current command value given to the command value calculation means. Power control device.

43. The phase adjustment means has a plurality of functions or coefficients that can be used to calculate the adjusted phase, The system further comprises a switching command means for selectively switching, according to the electric quantity, the function or coefficient to be used for calculating the adjusted phase from among the plurality of functions or coefficients. The power control device according to claim 27.

44. The phase adjustment means has one or more modifiable time constants and / or coefficients used in calculating the adjusted phase, The values ​​of the time constant and / or coefficient to be used in the calculation of the adjusted phase can be set to the value of the signal input from outside the phase adjustment means. The power control device according to claim 27.

45. A power control device for controlling a power converter connected to an AC electrical circuit, An electrical quantity measuring means for measuring the amount of electricity in the aforementioned electrical circuit, A phase calculation means for determining the phase of the electric quantity measured by the electric quantity measuring means, A phase adjustment means for adjusting the phase of the electric quantity determined by the phase calculation means, A command value calculation means for determining a control command value for the power converter based on the phase adjusted by the phase adjustment means, It is equipped with, The phase calculation means performs an αβ transform or a dq transform, The phase adjustment means generates an adjusted phase by adjusting the phase of the electric quantity after αβ conversion or dq conversion, and outputs a power of the adjusted phase. Power control device.

46. A power control device for controlling a power converter connected to an AC electrical circuit, An electrical quantity measuring means for measuring the amount of electricity in the aforementioned electrical circuit, A phase calculation means for determining the phase of the electric quantity measured by the electric quantity measuring means, A command value calculation means for determining a control command value for the power converter based on the phase of the electric quantity obtained by the phase calculation means, A phase adjustment means for adjusting the phase of the control command value obtained by the command value calculation means, AC waveform generation means generates an AC waveform of the control command value by converting the phase of the control command value, whose phase has been adjusted by the phase adjustment means, into a two-phase to three-phase. It is equipped with, The phase calculation means performs an αβ transform or a dq transform, The phase adjustment means generates an adjusted phase by adjusting the phase of the electric quantity after αβ conversion or dq conversion, and outputs a power of the adjusted phase. Power control device.

47. A power control device for controlling a power converter connected to an AC electrical circuit, An electrical quantity measuring means for measuring the amount of electricity in the aforementioned electrical circuit, A phase measuring means that converts the amount of electricity measured by the aforementioned electrical quantity measuring means into a three-phase to two-phase and then determines the phase of said electrical quantity, A phase adjustment means for adjusting the phase of the electric quantity determined by the phase measuring means, A phase calculation means for determining the phase of an electric quantity from an electric quantity whose phase has been adjusted by the phase adjustment means, A command value calculation means for determining a control command value for the power converter based on the phase of the electric quantity obtained by the phase calculation means, AC waveform generation means generates an AC waveform of the control command value obtained by the command value calculation means by performing a two-phase to three-phase conversion. It is equipped with, The phase calculation means performs an αβ transform or a dq transform, The phase adjustment means generates an adjusted phase by adjusting the phase of the electric quantity after αβ conversion or dq conversion, and outputs a power of the adjusted phase. Power control device.

48. A power control device for controlling a power converter connected to an AC electrical circuit, An electrical quantity measuring means for measuring the amount of electricity in the aforementioned electrical circuit, A phase calculation means for determining the phase of the electric quantity measured by the electric quantity measuring means, A command value calculation means for determining a control command value for the power converter based on the phase of the electric quantity obtained by the phase calculation means, AC waveform generation means that generates an AC waveform of the control command value obtained by the command value calculation means by performing a two-phase to three-phase conversion of the control command value, Phase adjustment means for adjusting the phase of the command value of the AC waveform converted by the AC waveform generation means. It is equipped with, The phase calculation means performs an αβ transform or a dq transform, The phase adjustment means generates an adjusted phase by adjusting the phase of the electric quantity after αβ conversion or dq conversion, and outputs a power of the adjusted phase. Power control device.

49. A power control device for controlling a power converter connected to an AC electrical circuit, An electrical quantity measuring means for measuring the amount of electricity in the aforementioned electrical circuit, A first phase calculation means for determining the phase of the electric quantity measured by the electric quantity measuring means, A phase adjustment means for adjusting the phase of the electric quantity determined by the first phase calculation means, AC waveform generation means for generating an AC waveform of an electric quantity whose phase has been adjusted by the phase adjustment means, A second phase calculation means for determining the phase of the AC waveform of the electric quantity generated by the AC waveform generation means, A command value calculation means that calculates a control command value for the power converter based on the phase of the electric quantity obtained by the second phase calculation means. It is equipped with, The phase calculation means performs an αβ transform or a dq transform, The phase adjustment means generates an adjusted phase by adjusting the phase of the electric quantity after αβ conversion or dq conversion, and outputs a power of the adjusted phase. Power control device.

50. A power control device for controlling a power converter connected to an AC electrical circuit, An electrical quantity measuring means for measuring the amount of electricity in the aforementioned electrical circuit, A command value calculation means for determining a control command value for the power converter based on the amount of electricity measured by the amount of electricity measuring means, A phase calculation means for determining the phase of the electric quantity measured by the electric quantity measuring means, A phase adjustment means for adjusting the phase of the electric quantity determined by the phase calculation means, A control signal generation means that generates a control signal using a signal indicating the difference before and after the phase adjustment adjusted by the phase adjustment means, It is equipped with, The phase calculation means performs an αβ transform or a dq transform, The phase adjustment means generates an adjusted phase by adjusting the phase of the electric quantity after αβ conversion or dq conversion, calculates the power of the adjusted phase and outputs it. The signal generated by the control signal generation means is used to control the active power command value given to the power control device, the voltage command value given to the command value calculation means, or the current command value given to the command value calculation means. The phase adjustment means is The power of the adjusted phase is calculated and output. Power control device.

51. A power control device for controlling a power converter of a rotating machine connected to an AC electrical circuit, An electrical quantity measuring means for measuring the amount of electricity in the aforementioned electrical circuit, A command value calculation means for determining a control command value for the power converter based on the amount of electricity measured by the amount of electricity measuring means, A phase calculation means for determining the phase of the electric quantity measured by the electric quantity measuring means, A phase adjustment means for adjusting the phase of the electric quantity determined by the phase calculation means, A control signal generation means that generates a control signal using a signal indicating the difference before and after the phase adjustment adjusted by the phase adjustment means, It is equipped with, The phase calculation means performs an αβ transform or a dq transform, The phase adjustment means generates an adjusted phase by adjusting the phase of the electric quantity after αβ conversion or dq conversion, calculates the power of the adjusted phase and outputs it. The signal generated by the control signal generation means is used to control the active power command value given to the power control device, the voltage command value given to the command value calculation means, or the current command value given to the command value calculation means. Power control device.

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