Instruction generation device and instruction generation method

Abstract

The rotation calculation unit calculates the rotation speed of the virtual generator based on a rotor model that simulates the driving of the virtual generator and calculates the rotation speed of the virtual generator. The target power determination unit determines the target values ​​of the effective power and reactive power of the inverter based on the calculated rotation speed. The instruction generation unit generates a control instruction for the inverter based on the determined target values ​​of the effective power and reactive power.

Description

Technical Field

[0001] The invention relates to an instruction generating device and an instruction generating method for generating control instructions of an inverter of a direct current power supply device.

[0002] This application claims priority based on Tokugan Application No. 2019-017462 filed in Japan on February 1, 2019, the contents of which are hereby incorporated by reference. Background Art

[0003] Patent Document 1 discloses a technology for achieving system stabilization by providing an inverter with the functions of a synchronous generator governor and an AVR (Automatic Voltage Regulator).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2017-208932 Summary of the invention

[0007] Problems to be solved by the invention

[0008] According to the technology described in Patent Document 1, the inverter controls the active power, reactive power and voltage frequency based on the model of the synchronous generator. However, a general inverter outputs AC power in synchronization with the voltage frequency of the bus through a PLL (Phase Lock Loop) circuit, so the voltage frequency cannot be controlled based on the model of the synchronous generator.

[0009] An object of the present invention is to provide a command generation device and a command generation method, which use an inverter that converts DC power output by a DC power supply device into AC power synchronized with the frequency of a bus, thereby achieving system stabilization against load fluctuations.

[0010] Means for solving problems

[0011] According to a first embodiment of the present invention, an instruction generating device is an instruction generating device that generates control instructions for an inverter that converts DC power output by a DC power supply device into AC power synchronized with the frequency of a bus, and comprises: a rotation calculation unit that calculates the rotation speed of the virtual generator based on a rotor model, wherein the rotor model simulates the drive of the virtual generator and calculates the rotation speed of the virtual generator; a target power determination unit that determines a target value of the effective power of the inverter based on the calculated rotation speed; and an instruction generating unit that generates control instructions for the inverter based on the determined target value of the effective power.

[0012] According to the second embodiment of the present invention, the instruction generating device of the first embodiment may also further include a rotation target determination unit, which determines a target value of the rotation speed of the virtual generator that decreases monotonically with respect to the effective power based on the effective power of the bus, and the rotation calculation unit calculates the rotation speed of the virtual generator based on the rotor model and the determined target value of the rotation speed.

[0013] According to the third embodiment of the present invention, the instruction generating device of the second embodiment may also include a function updating unit, which updates the intercept of the attenuation function so that the attenuation function passes through the effective power instruction and the voltage frequency of the bus, and the rotation target determination unit determines the target value of the rotation speed based on the attenuation function that specifies the relationship between the effective power of the bus and the target value of the rotation speed of the virtual generator.

[0014] According to the fourth embodiment of the present invention, the instruction generating device of any one of the first embodiment to the third embodiment may also further include a driving torque (torque) calculation unit, which calculates a value related to the driving torque of the virtual generator based on a regulator model, and the regulator model determines the value related to the driving torque of the virtual generator based on the difference between the effective voltage of the bus and the effective power instruction, the difference between the target value of the speed of the virtual generator and the calculated speed, and the difference between the target value and the measured value of the bus voltage, and the rotation calculation unit calculates a value related to the rotation of the virtual generator based on the calculated value related to the driving torque and the rotor model.

[0015] According to the fifth embodiment of the present invention, the instruction generation method is an instruction generation method for generating control instructions for an inverter that converts DC power output by a DC power supply device into AC power synchronized with the frequency of a bus, and the method comprises: a step of calculating the rotational speed of the virtual generator based on a rotor model, wherein the rotor model simulates the drive of the virtual generator and calculates the rotational speed of the virtual generator; a step of determining a target value of the effective power of the inverter based on the calculated rotational speed; and a step of generating control instructions for the inverter based on the determined target value of the effective power.

[0016] Effects of the Invention

[0017] According to at least one of the above aspects, the command generation device uses an inverter that converts DC power output by the DC power supply device into AC power synchronized with the frequency of the bus, thereby stabilizing the system against load fluctuations. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic block diagram showing the configuration of the power supply system according to the first embodiment.

[0019] Figure 2 It is a schematic block diagram showing the structure of the command generating device according to the first embodiment.

[0020] Figure 3 It is a block diagram showing an example of the AVR model according to the first embodiment.

[0021] Figure 4 This is a block diagram showing an example of a regulator model according to the first embodiment.

[0022] Figure 5 It is a block diagram showing an example of a rotor model according to the first embodiment.

[0023] Figure 6 It is a schematic block diagram showing the structure of the command generating device according to the second embodiment.

[0024] Figure 7 It is a diagram showing a droop function according to the second embodiment.

[0025] Figure 8 It is a diagram showing a method of updating the attenuation function according to the second embodiment.

[0026] Fig. 9 This is a block diagram showing an example of a regulator model according to the third embodiment.

[0027] Fig.10 is a schematic block diagram showing the structure of a computer according to at least one embodiment. DETAILED DESCRIPTION

[0028] <First Embodiment>

[0029] Figure 1 It is a schematic block diagram showing the configuration of the power supply system according to the first embodiment.

[0030] 《Structure of the power supply system》

[0031] The power supply system 1 of the first embodiment includes an engine generator 10, a solar power generator 20, a power storage device 30, a command generation device 33, and a power control device 40. The power supply system 1 supplies power to a load L by autonomous operation. That is, the power supply system 1 is a so-called micro grid system or an off-grid system. The engine generator 10, the solar power generator 20, and the power storage device 30 are connected to a bus bar, and supply power to the load L via the bus bar.

[0032] The engine generator 10 includes an engine 11, a generator 12, a regulator 13, and an AVR (Automatic Voltage Regular) 14. The engine generator 10 is an AC generator that generates AC power by driving the generator 12 through the rotation of the engine 11.

[0033] The regulator 13 controls the speed (rotation number) of the engine 11 through the Hz-kW attenuation characteristic. The regulator characteristic of the engine generator 10 is represented by the slope of a linear function connecting the plot points related to the rated output and the rated frequency, and the plot points related to the stable frequency that is stable in a no-load state when the load is cut off from zero output and the rated output. That is, the Hz-kW attenuation characteristic is a characteristic that the output decreases as the frequency increases. In addition, in other embodiments, the regulator characteristic can also be achieved by PID (Proportional Integral Differential) control. AVR14 controls the current supplied to the excitation winding of the generator 12 through the V-kbar attenuation characteristic, thereby adjusting the terminal voltage of the generator 12. The V-kbar attenuation characteristic is a characteristic that the reactive power decreases as the voltage increases. In addition, in other embodiments, other AC generators can also be used instead of the engine generator 10.

[0034] The solar power generator 20 includes a solar cell 21 and an inverter 22. The solar cell 21 is a DC power supply device that converts solar energy into DC power. The inverter 22 converts the DC power generated by the solar cell 21 into AC power. In addition, the inverter 22 and the solar cell 21 do not have to be arranged one-to-one. For example, multiple solar cells 21 can be connected to one inverter 22. In addition, in other embodiments, other renewable energy generators such as wind turbines can be used instead of the solar power generator 20.

[0035] The power storage device 30 includes a secondary battery 31 and an inverter 32. The control command of the inverter 32 includes a target value of effective power and a target value of reactive power. Based on the command from the command generation device 33, the inverter 32 converts the DC power output by the secondary battery 31 into AC power synchronized with the voltage frequency of the bus and supplies it to the bus. The inverter 32 synchronizes the output power with the voltage frequency of the bus through PLL control. In addition, based on the control command generated by the command generation device 33 according to the command from the power control device 40, the inverter 32 converts part of the AC power flowing through the bus into DC power and charges the secondary battery 31. As the secondary battery 31, for example, a lithium-ion secondary battery can be used. The inverter 32 is a general current control inverter that operates according to the control command of the control related to PQ. In addition, the inverter 32 of other embodiments can also operate according to the control command related to the target value of apparent power, the target value of the power factor angle, and the target value of the voltage frequency.

[0036] In addition, the inverter 32 and the secondary battery 31 do not necessarily need to be provided one to one. For example, a plurality of secondary batteries 31 may be connected to one inverter 32 .

[0037] The command generation device 33 generates a control command for controlling the inverter 32 of the power storage device 30 based on the command from the power control device 40, and outputs the control command to the power storage device 30. The command generation device 33 is a device provided separately from the power storage device 30.

[0038] The power control device 40 monitors the power value of the bus and outputs charge and discharge instructions to the engine generator 10 and the power storage device 30. For example, when the power generated by the solar power generator 20 is above a predetermined threshold value during the day, the power control device 40 outputs a power instruction to reduce or stop the power generation to the engine generator 10. In addition, when the power generated by the solar power generator 20 is less than a predetermined threshold value at night or in bad weather, the power control device 40 outputs a power instruction to increase the power generation to the engine generator 10.

[0039] In addition, for example, the power control device 40 outputs a charge and discharge instruction for smoothing the variation of the generated power of the solar power generator 20 to the power storage device 30. In addition, the power control device 40 compares the power value of the bus with the required power value of the load L, and outputs the charge and discharge instruction to the power storage device 30 based on the power difference.

[0040] 《Structure of instruction generation device》

[0041] Figure 2 It is a schematic block diagram showing the structure of the command generating device according to the first embodiment.

[0042] The command generation device 33 of the first embodiment includes an ammeter 322, a voltmeter 323, and a computer 324. The ammeter 322 measures the current at the output end of the inverter 32. The voltmeter 323 measures the voltage at the output end of the inverter 32. The computer 324 generates a control command based on the measured values ​​of the ammeter 322 and the voltmeter 323.

[0043] The computer 324 includes a model storage unit 3241 , a command receiving unit 3242 , a measured value acquiring unit 3243 , an exciting voltage calculating unit 3244 , a driving torque calculating unit 3245 , a rotation calculating unit 3246 , a target power determining unit 3247 , and a command generating unit 3248 .

[0044] The model storage unit 3241 stores mathematical models that simulate the behavior of the virtual generator. Specifically, the model storage unit 3241 stores an AVR model M1 that simulates the behavior of the AVR of the virtual generator, a regulator model M2 that simulates the behavior of the regulator of the virtual generator, and a rotor model M3 that simulates the behavior of the rotor of the virtual generator. The AVR model M1 outputs the excitation voltage and electric torque of the virtual generator by inputting the measured value of reactive power, the reactive power command value, the effective (effective) voltage value, and the effective voltage command value. The regulator model M2 outputs the driving torque value of the virtual generator by inputting the measured value of effective power, the effective power command value, the angular velocity of the rotor of the virtual generator, and the angular velocity command value. The rotor model M3 outputs the angular velocity and phase angle of the rotor of the virtual generator by inputting the electric torque value and the driving torque value of the virtual generator. The details of each mathematical model will be described later.

[0045] The command receiving unit 3242 receives a charge and discharge command from the power control device 40. The charge and discharge command includes a command value of active power, a command value of reactive power, an effective voltage command value, and an angular velocity command value.

[0046] The measured value acquisition unit 3243 acquires the measured values ​​of the ammeter 322 and the voltmeter 323. In addition, the measured value acquisition unit 3243 calculates the voltage value and current value contributing to the effective power at the output end, the voltage value and current value contributing to the reactive power, the effective voltage value, the effective power value, and the reactive power value based on the measured values ​​of the ammeter 322 and the voltmeter 323 and the phase angle of the rotor of the virtual generator.

[0047] The excitation voltage calculation unit 3244 calculates the excitation voltage value and electric torque value of the virtual generator by inputting the reactive power command value and the effective voltage command value received by the command receiving unit 3242 and the reactive power value and the effective voltage value acquired by the measured value acquisition unit 3243 into the AVR model M1. The excitation voltage value and the electric torque value of the virtual generator are examples of values ​​related to the excitation voltage of the virtual generator.

[0048] The driving torque calculation unit 3245 calculates the driving torque value of the virtual generator by inputting the effective power command value and angular velocity command value received by the command receiving unit 3242, the measured value of the effective power acquired by the measured value acquisition unit 3243, and the angular velocity of the rotor of the virtual generator calculated by the rotation calculation unit 3246 in the previous control into the regulator model M2. The driving torque value is an example of a value related to the driving torque of the virtual generator.

[0049] The rotation calculation unit 3246 calculates the angular velocity and phase angle of the rotor of the virtual generator by inputting the electric torque value calculated by the excitation voltage calculation unit 3244 and the driving torque value calculated by the driving torque calculation unit 3245 into the rotor model M3. The angular velocity and phase angle of the rotor of the virtual generator are examples of values ​​related to the rotation of the rotor of the virtual generator.

[0050] The target power determination unit 3247 determines the target value of effective power and the target value of reactive power based on the excitation voltage value calculated by the excitation voltage calculation unit 3244, the voltage value and current value contributing to the effective power and the voltage value and current value contributing to the reactive power acquired by the measurement value acquisition unit 3243, and the phase angle of the rotor calculated by the rotation calculation unit 3246.

[0051] The command generation unit 3248 generates a control command for the inverter 32 based on the target value of active power and the target value of reactive power determined by the target power determination unit 3247 . The command generation unit 3248 outputs the generated control command to the inverter 32 .

[0052] The Structure of Mathematical Models

[0053] Figure 3 It is a block diagram showing an example of the AVR model according to the first embodiment.

[0054] The AVR model M1 receives the measured value Q of reactive power and the reactive power command value Q. * , effective voltage value V g And the effective voltage command value V * , output the excitation voltage value E and electric torque value T of the virtual generator e Specifically, the AVR model M1 includes addition points M11, M12, M13, P block M14, I block M15, and P block M16. The addition point M11 obtains the reactive power measurement value Q and the reactive power command value Q. * The P block M14 performs P control on the output of the addition point M11 based on the proportional gain KA1. The proportional gain KA1 is equivalent to the V-kbar attenuation gain of the virtual generator. The addition point M12 obtains the effective voltage value V g The effective voltage command value V* The addition point M13 obtains the difference between the output of the addition point M12 and the output of the P block M14. The I block M15 obtains the excitation voltage value E by performing an integral control based on the integral gain KA2 on the output of the addition point M13. The P block M16 multiplies the excitation voltage value E by the reactive current value I q and divided by the rotor's angular velocity ω R , thus the electric torque T of the virtual generator is obtained e .

[0055] Figure 4 This is a block diagram showing an example of a regulator model according to the first embodiment.

[0056] The regulator model M2 receives the measured value P of the effective power and the effective power command value P. * , the angular velocity of the rotor of the virtual generator ω R and the target value of angular velocity ω * , output the driving torque value T of the virtual generator d Specifically, the regulator model M2 includes: adding points M21, M22, M23, P block M24, PI block M25, and first-order delay block M26. The adding point M21 obtains the measured value P of the effective power and the effective power command value P * The P block M24 performs P control on the output of the addition point M21 based on the proportional gain KB1. The proportional gain KB1 is equivalent to the Hz-kW attenuation gain of the virtual generator. The addition point M22 obtains the angular velocity ω of the rotor of the virtual generator R and the target value of angular velocity ω * The addition point M23 obtains the sum of the output of the addition point M22 and the output of the P block M24. The PI block M25 performs PI control on the output of the addition point M23 based on the proportional gain KB2 and the integral gain KB3. The first delay block M26 performs a first delay control on the output of the PI block M25 related to the time constant KB4 to obtain the driving torque value T d .

[0057] Figure 5 It is a block diagram showing an example of a rotor model according to the first embodiment.

[0058] The rotor model M3 is input with the electric torque value T of the virtual generator. e And the driving torque value T d , the angular velocity ω of the rotor of the output virtual generator R and the phase angle θ R Specifically, the rotor model M3 includes an addition point M31, a first-order delay block M32, and an I block M33. The addition point M31 obtains the electric torque T of the virtual generator. e And the driving torque T dThe first-order delay block M32 performs a first-order delay control on the output of the addition point M31 related to the first-order delay gain 1 / D and the time constant M / D to obtain the rotor angular velocity ω R . I block M33 to the rotor angular velocity ω R Integrate and multiply by the proportional gain ω BASE , thus obtaining the phase θ of the rotor of the virtual generator R . Proportional gain ω BASE is the base frequency of the bus.

[0059] "action"

[0060] According to the above configuration, the computer 324 obtains the rotation angle, angular velocity, and excitation voltage value of the virtual generator based on the AVR model M1, the regulator model M2, and the rotor model M3, based on the effective power command value, the reactive power command value, the effective voltage command value, and the angular velocity command value and the measured values ​​of the ammeter 322 and the voltmeter 323. The computer 324 determines the target value of the effective power and the target value of the reactive power based on the rotation angle, angular velocity, and excitation voltage value of the virtual generator, and generates a control command for the inverter 32 based on the above. The inverter 32 operates according to the control command generated by the command generation device 33, thereby realizing the characteristics equivalent to the virtual generator.

[0061] 《Function and Effect》

[0062] The command generation device 33 of the first embodiment calculates the rotation speed of the virtual generator based on the rotor model M3, and outputs the target value of the effective power of the inverter 32 determined based on the calculated rotation speed as a control command to the inverter 32. Here, the command generation device 33 of the first embodiment does not specify the target value of the voltage frequency in the control command of the inverter 32. That is, the AC power output by the inverter 32 is synchronized with the voltage frequency of the bus, and the command generation device 33 controls the magnitude of the effective power of the AC power. Therefore, the command generation device 33 of the first embodiment uses the inverter 32 that converts the DC power output by the DC power supply device into AC power synchronized with the frequency of the bus, and can achieve stabilization of the system with respect to load fluctuations.

[0063] <Second Embodiment>

[0064] The command generating device 33 of the second embodiment does not control the voltage frequency of the inverter 32 but compensates for the variation of the voltage frequency of the bus accompanying the variation of the load L.

[0065] Figure 6 It is a schematic block diagram showing the structure of the command generating device according to the second embodiment.

[0066] The command generation device 33 of the second embodiment further includes a rotation target determination unit 3249 and a function update unit 3250 in addition to the configuration of the first embodiment. The model storage unit 3241 also stores a decay function F.

[0067] Figure 7 It is a diagram showing the attenuation function of the second embodiment.

[0068] The damping function F represents the relationship between the angular velocity of the rotor of the virtual generator and the effective power of the bus. In the damping function F, the effective power decreases monotonically with respect to the angular velocity of the rotor of the virtual generator. The slope of the damping function F may be the same slope as the damping characteristic of the regulator 13 .

[0069] The rotation target determination unit 3249 substitutes the measured value of the effective power of the bus into the damping function F stored in the model storage unit 3241 to determine the target value of the angular velocity of the rotor of the virtual generator.

[0070] When the command receiving unit 3242 receives the command value of the bus power, the function updating unit 3250 updates the intercept of the attenuation function F based on the value (the value after passing through the low-pass filter) related to the temporary delay of the difference between the command values ​​of the effective power before and after the change. Specifically, the value obtained by subtracting the command value of the effective power before the change from the command value of the effective power after the change is added to the intercept of the effective power axis of the current attenuation function F. That is, the function updating unit 3250 does not change the slope in the update of the attenuation function F.

[0071] 《Update method of decay function》

[0072] Figure 8 It is a diagram showing a method of updating the attenuation function according to the second embodiment.

[0073] Here, the updating method of the attenuation function F is described as an example. At time T0, the model storage unit 3241 stores the attenuation function F0. The attenuation function F0 is a function in which the intercept of the effective power axis is set to P0. Therefore, the rotation target determination unit 3249 determines the target value of the angular velocity of the rotor by substituting the effective power of the bus into the attenuation function F0.

[0074] Here, at time T1, it is assumed that the instruction receiving unit 3242 receives P1 as the instruction value of the effective power from the power control device 40. At this time, the function updating unit 3250 calculates ΔP based on the temporary delay of the deviation P1-P0 of the instruction value of the effective power, and updates the intercept of the effective power axis of the attenuation function F0 to P1+ΔP, thereby obtaining the attenuation function F1. The function updating unit 3250 rewrites the attenuation function F0 into the attenuation function F1. Therefore, at time T1, the rotation target determination unit 3249 determines the target value of the angular velocity of the rotor by substituting the effective power of the bus into the attenuation function F1. Figure 8 In the example shown, since the command value of the effective power decreases, the intercept of the effective power axis decreases at time T1. Accordingly, the rotation target determination unit 3249 determines the target value of the angular velocity to be a slightly smaller value than that at time T0. That is, the function update unit 3250 updates the intercept of the attenuation function based on the value related to the temporary delay of the deviation P1-P0 of the command value, thereby preventing the target value of the angular velocity from changing suddenly and causing oscillation.

[0075] If the target value of the angular velocity decreases, the driving torque calculated by the driving torque calculation unit 3245 decreases, and the angular velocity calculated by the rotation calculation unit 3246, that is, the increment of the rotor phase, also decreases. Thus, the command generation device 33 can reduce the effective power output by updating the damping function F.

[0076] Then, at time T2, the value of the intercept of the effective power axis in the attenuation function F reaches P1. That is, at time T2, the rotation target determination unit 3249 determines the target value of the angular velocity of the rotor by substituting the effective power of the bus into the attenuation function F2. Thus, the rotation target determination unit 3249 can determine the target value of the angular velocity according to the attenuation function even after the command value of the effective power is changed. That is, the command generation device 33 of the second embodiment can compensate for the change in the voltage frequency of the bus accompanying the change in the load L without controlling the voltage frequency of the inverter 32.

[0077] <Third Embodiment>

[0078] The command generating device 33 of the third embodiment stabilizes the power of the bus even when there is no power supply from the alternator to the bus, such as when the engine generator 10 is disconnected.

[0079] The command generation device 33 of the third embodiment has the same configuration as the command generation device 33 of the first embodiment. On the other hand, the regulator model M2 of the third embodiment is different from the regulator model of the first embodiment.

[0080] Fig. 9 This is a block diagram showing an example of a regulator model according to the third embodiment.

[0081] The regulator model M2 of the third embodiment further includes an addition point M27 and a P block M28 in addition to the configuration of the first embodiment. The addition point M27 obtains the measured value V of the bus voltage and the bus effective voltage command value V * In other embodiments, the output of the addition point M12 of the AVR model M1 may be obtained instead of the addition point M27. The P block M28 performs a proportional gain K on the output of the addition point M27. B5 Then, the addition point M23 obtains the sum of the output of the addition point M22, the output of the P block M24, and the output of the P block M28. That is, according to the regulator model M2 of the third embodiment, the output effective power can be changed not only according to the frequency deviation but also according to the voltage deviation.

[0082] When the bus power is supplied only by the power supply device via the inverter, only the bus voltage changes when the load changes, and the voltage frequency does not change. In contrast, the command generation device 33 of the third embodiment changes the output effective power not only according to the frequency deviation but also according to the voltage deviation. Therefore, the command generation device 33 of the third embodiment can make the inverter 32 have synchronization force even when the bus power is supplied only by the power supply device via the inverter.

[0083] <Other Implementation Methods>

[0084] As mentioned above, one embodiment has been described in detail with reference to the drawings, but the specific structure is not limited to the above structure, and various design changes and the like can be made.

[0085] For example, the structure of the PID control block in the model of the above embodiment is only an example, and in other embodiments, it can also be replaced by other PID control blocks. For example, in other embodiments, the P block M14 of the AVR model M1 can also be replaced by an I block, a D block, a PI block, etc.

[0086] <Computer Architecture>

[0087] Fig.10 is a schematic block diagram showing the structure of a computer according to at least one embodiment.

[0088] The computer 324 of at least one of the above-described embodiments includes a processor 91 , a main memory 92 , a storage 93 , and an interface 94 .

[0089] The operations of the above-mentioned processing units are stored in the form of programs in the storage 93. The processor 91 reads the program from the storage 93 and expands it in the main memory 92, and executes the above-mentioned processing according to the program. In addition, the processor 91 ensures storage areas corresponding to the above-mentioned storage units in the main memory 92 according to the program.

[0090] The program may also be used to implement a portion of the functions of the computer 324. For example, the program may also function by combining with other programs already stored in the storage 93, or by combining with other programs installed in other devices. In addition, in other embodiments, the computer 324 may have a customized LSI (Large Scale Integrated Circuit) such as a PLD (Programmable Logic Device) in addition to the above structure, or instead of the above structure. Examples of PLDs include PAL (Programmable Array Logic), GAL (Generic Array Logic), CPLD (Complex Programmable Logic Device), and FPGA (Field Programmable Gate Array). In this case, part or all of the functions implemented by the processor 91 may also be implemented by the integrated circuit.

[0091] Examples of the storage 93 include a HDD (Hard Disk Drive), an SSD (Solid State Drive), a magnetic disk, an optical magnetic disk, a CD-ROM (Compact Disc Read Only Memory), a DVD-ROM (Digital Versatile Disc Read Only Memory), and a semiconductor memory. The storage 93 may be an internal medium directly connected to a bus of the computer 324, or an external medium connected to the computer 324 via an interface 94 or a communication line. In addition, when the program is distributed to the computer 324 via a communication line, the computer 324 that receives the distribution may also expand the program in the main memory 92 and execute the above-mentioned processing. In at least one embodiment, the storage 93 is a non-temporary tangible storage medium.

[0092] In addition, the program may be used to realize a part of the above-mentioned functions. Furthermore, the program may be a so-called difference file (difference program) that realizes the above-mentioned functions by combining with other programs already stored in the storage 93.

[0093] Industrial Applicability

[0094] The command generating device uses an inverter that converts the DC power output by the DC power supply device into AC power synchronized with the bus frequency, thereby stabilizing the system against load fluctuations.

[0095] Description of Reference Numerals

[0096] 1 power supply system; 10 engine generator; 11 engine; 12 generator; 13 regulator; 14 AVR; 20 solar power generator; 21 solar cell; 22 inverter; 30 power storage device; 31 secondary battery; 32 inverter; 33 instruction generation device; 322 ammeter; 323 voltmeter; 324 computer; 3241 model storage unit; 3242 instruction receiving unit; 3243 measured value acquisition unit; 3244 excitation voltage calculation unit; 3245 drive torque calculation unit; 3246 rotation calculation unit; 3247 target power determination unit; 3248 instruction generation unit; 3249 rotation target determination unit; 3250 function update unit; 40 power control device.

Claims

1. A command generating device for generating a control command for an inverter for converting DC power outputted by a DC power supply device into AC power synchronized with a frequency of a bus, comprising: a rotation target determination unit that determines, based on the effective power of the bus, a target value of the rotation speed of the virtual generator that decreases monotonically with respect to the effective power; A rotation calculation unit calculates the rotation speed of the virtual generator based on a rotor model and the determined target value of the rotation speed, wherein: The rotor model simulates the driving of the virtual generator and calculates the rotation speed of the virtual generator; a target power determination unit that determines target values ​​of active power and reactive power of the inverter based on the calculated rotation speed; as well as A command generating unit generates a control command for the inverter based on the determined target values ​​of the active power and the reactive power.

2. The instruction generation device according to claim 1, wherein: The method further comprises a function updating unit that updates an intercept of a decay function that specifies a relationship between the effective power of the bus and a target value of the rotation speed of the virtual generator according to a difference between the effective power commands before and after the change when the effective power command is changed. The rotation target determination unit determines a target value of the rotation speed based on the damping function.

3. The instruction generation device according to claim 1 or 2, wherein: The controller further comprises a driving torque calculation unit, which calculates a value related to the driving torque of the virtual generator based on a regulator model, wherein the regulator model determines the value related to the driving torque of the virtual generator based on a difference between the effective voltage of the bus and an effective power command, a difference between a target value of the rotation speed of the virtual generator and the calculated rotation speed, and a difference between a target value and a measured value of the bus voltage, The rotation calculation unit calculates a value related to the rotation of the virtual generator based on the calculated value related to the drive torque and the rotor model.

4. A command generation method for generating a control command for an inverter that converts DC power output by a DC power supply device into AC power synchronized with the frequency of a bus, comprising: A step of determining, based on the effective power of the bus, a target value of the rotation speed of the virtual generator that decreases monotonically with respect to the effective power; A step of calculating the rotation speed of the virtual generator based on a rotor model and the determined target value of the rotation speed, wherein the rotor model simulates the driving of the virtual generator and calculates the rotation speed of the virtual generator; The step of determining a target value of the effective power of the inverter based on the calculated rotation speed; and A step of generating a control command for the inverter based on the determined target value of the active power.

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