Power supply unit and voltage generation method

Abstract

To provide a power source device in which the accuracy of an actual frequency of an output voltage can be improved.SOLUTION: In a power source device, the frequency of an output voltage is controlled to input / output power from / to a power system. The power source device includes a calculation unit that calculates a command frequency for the output voltage on the basis of first power which is a target of the output to the power system, second power which is actually inputted from / outputted to the power system, and a prescribed set frequency, a correction unit that corrects the command frequency, a generation unit that generates a control signal for controlling the output voltage on the basis of the corrected command frequency, and an output unit that outputs, to the power system, the output voltage generated on the basis of the control signal. The correction unit corrects the command frequency on the basis of the difference between an actual frequency of the output voltage and the uncorrected command frequency obtained during a steady state such that the first power and the second power become equal to each other during the steady state.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a power supply device and a voltage generation method. [Background technology]

[0002] Synchronous generators contribute to maintaining the frequency of power systems through the inertia of their rotating bodies. In recent years, pseudo-synchronous generators that simulate synchronous generators by controlling the output of an inverter have become known (for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Patent No. 7023430 [Overview of the project] [Problems that the invention aims to solve]

[0004] By the way, in typical quasi-synchronous generators using a voltage-controlled (GFM: Grid-Forming) method, the accuracy of the actual output voltage frequency relative to the commanded output voltage frequency is not considered.

[0005] Therefore, if the accuracy of the actual frequency of the output voltage is low and contains significant errors, there may be a discrepancy between the target power input and output to the power system and the power actually input and output to the power system.

[0006] This invention has been made in view of these problems, and aims to provide a power supply device that can improve the accuracy of the actual frequency of the output voltage. [Means for solving the problem]

[0007] One invention for achieving the above objective is a power supply device that inputs and outputs power to and from a power system by controlling the frequency of the output voltage, comprising: a calculation unit that calculates a command frequency for the output voltage based on a target first power to be output to the power system, a second power actually input and output to and from the power system, and a predetermined set frequency; a correction unit that corrects the command frequency; a generation unit that generates a control signal for controlling the output voltage based on the corrected command frequency; and an output unit that outputs the output voltage generated based on the control signal to the power system, wherein the correction unit corrects the command frequency based on the error between the command frequency before correction and the actual frequency of the output voltage obtained in a steady state, such that the first power and the second power coincide in a steady state. Other features of the present invention will be made clear by the description herein. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a power supply device that can improve the accuracy of the actual frequency of the output voltage. [Brief explanation of the drawing]

[0009] [Figure 1] This diagram illustrates an example of a power system 1 equipped with a typical power supply unit 5. [Figure 2] This diagram illustrates an example of a power system 1 equipped with a typical power supply unit 5. [Figure 3] This is a diagram illustrating the calculation unit 30 of a typical power supply unit 5. [Figure 4] This diagram illustrates a method for verifying the accuracy of the actual frequency of the output voltage using a typical power supply unit 5. [Figure 5] This diagram illustrates a method for verifying the accuracy of the actual frequency of the output voltage using a typical power supply unit 5. [Figure 6] This figure shows an example of the relationship between the frequency of the reference power supply 6 and the error in the output voltage frequency. [Figure 7]Embodiment 6 is a diagram illustrating an example of a power system 1 in which a power supply unit 2 is provided. [Figure 8] This is a diagram illustrating the correction unit 31 of the power supply unit 2 in Embodiment 6. [Figure 9] This figure shows an example of a data table showing the error between the command frequency before correction and the output voltage frequency. [Figure 10] This figure shows an example of a data table showing the command frequency before correction and the command frequency after correction. [Modes for carrying out the invention]

[0010] ==Implementation Method== <<General Power Supply Unit 5>> Figure 1 is a diagram illustrating an example of a power system 1 equipped with a general power supply unit 5. Here, before describing the power supply unit 2 (described later) of this embodiment, we will describe the general power supply unit 5. The general power supply unit 5 is a so-called pseudo-synchronous generator that simulates a synchronous generator having a rotating body using a voltage control (GFM: Grid-Forming) method.

[0011] Specifically, power supply unit 5 has an output voltage v out frequency f out By controlling power P between the power system 1 and the power grid 1 out This is a device that inputs and outputs power P. out When positive, this represents the power output from power supply unit 5 to power system 1, and when negative, it represents the power input from power system 1 to power supply unit 5.

[0012] The power supply unit 5 is connected to the power system 1 via a line reactance X.

[0013] The power supply unit 5 comprises a control unit 7 and an output unit 20. The hardware configuration of the control unit 7 will be described first, followed by a description of the functional blocks of the power supply unit 2.

[0014] <Hardware configuration of control unit 7> The control device 7 includes a DSP (Digital Signal Processor) 35 and a storage device 36 (Figure 1).

[0015] [DSP35] The DSP35 realizes various functions of the control unit 7 by executing a predetermined program stored in the storage device 36.

[0016] [Storage device 36] The storage device 36 includes a non-temporary (e.g., non-volatile) storage device that stores various data executed or processed by the DSP 35.

[0017] The storage device 36 further includes, for example, RAM (Random-Access Memory) (memory 36a, described later), and is used as a temporary storage area for various programs and data.

[0018] <Functional blocks of power supply unit 5> Figure 2 is a diagram illustrating an example of a power system 1 equipped with a general power supply unit 5, and more particularly, a diagram illustrating the functional blocks of the power supply unit 5. As a result of the DSP 35 executing a predetermined program, the control device 7 is equipped with a calculation unit 30, an integrator 32, an instantaneous voltage control unit 33, and a PWM pulse generation unit 34.

[0019] As a result, the power supply unit 5 comprises a calculation unit 30, an integrator 32, an instantaneous voltage control unit 33, a PWM pulse generation unit 34, and an output unit 20. Each of these will be described below.

[0020] Furthermore, if the same reference numeral is used for blocks shown in the drawing, those blocks are identical.

[0021] [Calculation section 30] The calculation unit 30 simulates a synchronous generator using the GFM method, thereby determining the output voltage v that is output to the power system 1. out Command frequency f ref Calculate.

[0022] Specifically, the calculation unit 30 calculates the command frequency f ref for the output voltage v based on the target power P out (corresponding to the "first power") input and output to the power system 1, the power P n,ref actually input and output to the power system 1 (corresponding to the "second power"), and a predetermined set frequency f out for the output voltage v ref .

[0023] In the following description, the inertia constant of the rotating body of the synchronous generator simulated by the calculation unit 30 is denoted as H, and the damping constant is denoted as D

[0024] The inertia constant H is a parameter for simulating the difficulty of the rotating body to respond to an external force. That is, the larger the inertia constant H of the rotating body, the more difficult it is to rotate around a predetermined axis and the more difficult it is to stop. The inertia constant H is a parameter corresponding to the moment of inertia

[0025] Also, the damping constant D is a parameter for simulating the resistance received by the rotating body in the direction opposite to the rotation, for example, due to friction or the like. That is, the larger the damping constant D, the easier it is for the rotational frequency of the rotating body to decay

[0026] FIG. 3 is a diagram for explaining the calculation unit 30 of a general power supply device 5. The calculation unit 30 includes adders 300, 301, 305, multipliers 302, 303, 306, 307, and an integrator 304

[0027] Although details will be described later, in the processing from the multiplier 302 to the integrator 304 in FIG. 3, the calculation unit 30 outputs the command frequency f ref in accordance with the inertia constant H. At this time, since the larger the inertia constant H, the more difficult it is for the rotating body to respond to an external force, the variation of the command frequency f ref is suppressed to be small

[0028] Also, in the processing from the adder 305 to the adder 301 in FIG. 3, the calculation unit 30 calculates the command frequency f<00,000,14>in accordance with the damping constant D, and the set frequency f n,refPower P corresponding to the difference D The following is calculated and output: In this case, the larger the damping constant D, the greater the power P. D The absolute value of is large.

[0029] Furthermore, in the processing from adder 300 to adder 301, the calculation unit 30 performs P H,in (=P ref -P out -P D ) is calculated and output to the multiplier 302. Here, P H,in If it is a positive value, the command frequency f ref It increases. Also, P H,in If the value is negative, the command frequency f ref It decreases.

[0030] The following describes the processes performed by each component of the calculation unit 30.

[0031] Adder 300 has power P ref From, Power P out The operation of subtracting is performed. As a result, the adder 300 calculates power P ref And, Power P out The difference (Power P) ref -P out Outputs ).

[0032] Adder 301 receives power P, which is the output of adder 300. ref -P out Therefore, the power P, which is the output of the multiplier 307 described later, is D By performing an operation to subtract power P, H,in (=P ref -P out -P D Outputs ).

[0033] The multiplier 302 receives power P from the adder 300. H,in We then perform an operation of multiplying by 1 / 2H (i.e., dividing by 2H), where H is the constant of inertia (as described above).

[0034] The multiplier 303 and the rated frequency f of power system 1 are applied to the inputs from multiplier 302. n Perform the multiplication operation. Rated frequency f of power system 1 n For example, within Japan, the frequency is 50Hz in eastern Japan and 60Hz in western Japan.

[0035] The integrator 304 performs a time integration operation on the input from the multiplier 303 over a predetermined period. Through this operation, the integrator 304 calculates the output voltage v that is output to the power system 1. out The command frequency f is the command value of the frequency. ref Outputs.

[0036] The adder 305 receives the command frequency f from the integrator 304. ref From, the set frequency f n,ref By performing an operation to subtract Δf, ref Outputs.

[0037] The multiplier 306 takes the input Δf from the adder 305. ref In contrast, the rated frequency f of power system 1 n Perform the division operation.

[0038] The multiplier 307 performs the operation of multiplying the input from the multiplier 306 by D, thereby generating the aforementioned P D The output is as follows: Here, D is the braking constant in the GFM control system (as described above).

[0039] [Integrator 32] The integrator 32 in Figure 1 receives the command frequency f from the calculation unit 30. ref The integrator 32 performs a time integration operation over a predetermined period. Through this operation, the integrator 32 obtains the phase θ, which is the command value for the phase of the output power output from the output unit 20. ref Outputs.

[0040] [Instantaneous voltage control unit 33] The instantaneous voltage control unit 33 receives the phase θ from the integrator 32 as input. ref And the output voltage v outThe command value is the command amplitude V. ref Based on this, a sinusoidal signal is generated as the fundamental wave in PWM control. The sinusoidal signal is output to the PWM pulse generation unit 34.

[0041] [PWM pulse generation unit 34] The PWM pulse generation unit 34 detects the intersection point between a carrier wave, which is realized, for example, as a triangular wave, and the fundamental wave, which is the input from the instantaneous voltage control unit 33. Based on this, the PWM pulse generation unit 34 determines the duty cycle of the PWM pulse and generates a PWM pulse having the determined duty cycle. The PWM pulse is output to the output unit 20, which drives the inverter circuit (described later) of the output unit 20.

[0042] [Output section 20] The output unit 20 includes a DC power supply 200 and an inverter circuit (not shown) including a plurality of switching elements. The inverter circuit converts the DC voltage from the DC power supply 200 into an AC voltage and outputs an output voltage v to the power system 1. out It outputs as follows. At this time, the inverter circuit generates an output voltage v based on the PWM pulse which is the output from the PWM pulse generation unit 34. out Outputs.

[0043] Through the processing of each component of the power supply unit 5 as described above, the output voltage v is sent from the output unit 20 to the power system 1. out The following will be output.

[0044] However, at this time, the output voltage v out The actual frequency (hereinafter referred to as "actual frequency f") out The command frequency f (referred to as ")" is output from the calculation unit 30. ref This does not match the command frequency f ref This may include errors. In such cases, the target power P of the input and output may be affected. ref And the power P that is actually input and output. out The two diverge.

[0045] Command frequency f refSuch errors arise from processing in the integrator 32, instantaneous voltage control unit 33, and PWM pulse generation unit 34 (particularly the processing in the PWM pulse generation unit 34).

[0046] In addition, in a typical power supply unit 5, the actual frequency f out "Accuracy" refers to the command frequency f ref Output voltage v out The actual frequency f out The accuracy is set to this value. In other words, the output voltage v out The actual frequency f out However, the command frequency f ref The closer it is to the frequency f out Its accuracy is high.

[0047] In a typical power supply unit 5, the output voltage v out The actual frequency f out The accuracy of the output voltage v is not considered. out The actual frequency f out There is no way to verify the accuracy of the output voltage v out The actual frequency f out There was no way to improve its accuracy.

[0048] Next, the power supply unit 2 of this embodiment will be described. As will be explained in detail later, the power supply unit 2 of this embodiment has an output voltage v based on the accuracy verification method described above. out The actual frequency f out This power supply unit is capable of improving accuracy.

[0049] <<How to verify frequency accuracy>> Output voltage v out The actual frequency f out The method for verifying the accuracy of the frequency f will be explained in detail. Figures 4 and 5 show the frequency f using a typical power supply 5. out This is a diagram explaining how to verify the accuracy.

[0050] [Device for verifying frequency accuracy] Figure 4 shows the frequency f outAs a measurement system 4 for confirming the accuracy, the above-described general power supply device 5 and a reference power supply 6 are shown. The power supply device 5 is connected to the reference power supply 6.

[0051] The power supply device 5 is a power supply device including the aforementioned calculation unit 30, integrator 32, instantaneous voltage control unit 33, PWM pulse generation unit 34, and output unit 20.

[0052] The reference power supply 6 is a power supply capable of controlling the frequency of the output voltage of the reference power supply 6 itself. Here, the error between the set frequency and the actual frequency of the output voltage of the reference power supply 6 is sufficiently small. That is, the error included in the actual frequency of the output voltage in the reference power supply 6 is out sufficiently small compared to the error included in the actual frequency f of the output voltage of the power supply device 5.

[0053] Hereinafter, the frequency of the output voltage of the reference power supply 6 will be referred to as the frequency f test Also, the frequency f of the output voltage of the reference power supply 6 test may be simply referred to as "the frequency f of the reference power supply 6 test ".

[0054] Hereinafter, a method for confirming the accuracy of the frequency f out using the power supply device 5 and the reference power supply 6 will be described in detail.

[0055] [Calculation formula for error f δ The error included in the actual frequency f of the output voltage v out of the power supply device 5 is referred to as "error f out ", and hereinafter, the calculation formula for error f δ will be obtained. Error f δ is the difference between the actual frequency f δ of the output voltage v out output by the output unit 20 and the command frequency f out output by the calculation unit 30 (the following formula). ref [Equation] [Equation]

[0056] ​ Here, in the steady state, the actual frequency f out And the frequency f of the reference power supply 6 test It is assumed that these coincide. This is because, in the GFM control performed by the calculation unit 30, the actual frequency f out This is to synchronize with the frequency of power system 1. This is also true when reference power source 6 is used instead of power system 1.

[0057] Therefore, error f δ This refers to the command frequency f in the steady state when the power supply unit 5 is connected to the reference power supply 6. ref And the frequency f of the reference power supply 6 test It is determined by the difference between the two (see the following equation).

number

[0058] Note that "steady state" refers to the frequency f of the reference power supply 6. test When the value is set to a predetermined value, a sufficient amount of time has elapsed since the power supply unit 5 and the reference power supply 6 were started. In a steady state, the command frequency f ref It converges to a certain value and then remains unchanged even as time passes.

[0059] In this embodiment, we calculate the value of the right-hand side of equation 2. The calculation performed by the calculation unit 30 shown in Figure 5 to calculate the value of the right-hand side of equation 2 will be described in detail.

[0060] As shown in Figure 5, in the accuracy verification method of this embodiment, the calculation unit 30 has power P ref And, Power P out And the frequency f of the reference power supply 6 test The following is input. Then, the calculation unit 30 outputs the command frequency f ref The following will be output.

[0061] First, at the output of adder 301, power P H,in Figure 5 can be formally represented by the following equation.

number

[0062] Here, P on the right side of equation 3 D This can be expressed by the following equation, based on the processing of adder 305, multiplier 306, and multiplier 307.

number

[0063] Power P is the output of adder 301. H,in The command frequency f obtained by performing operations on multiplier 302, multiplier 303, and integrator 304 for (Equation 3) ref This can be expressed by the following equation.

number

[0064] Substituting numbers 3 and 4 into number 5, we obtain the following equation.

number

[0065] Here, if we impose the condition that the derivative of both sides of equation 6 with respect to time t is 0 as a condition for a steady state, we obtain the following equation.

number

[0066] From the second equation in number 7, we obtain the following equation.

number

[0067] For equation 8, the error f shown in equation 2. δ Substituting the definition of and rearranging, we obtain the following equation.

number

[0068] Therefore, the error f δ This allows us to obtain the calculation formula (Equation 9). In other words, the set value is the rated frequency f n , power P ref , and the measured power P out By substituting this into equation 9, the error f δ You can obtain the value.

[0069] [Reference power supply 6 frequency f test And, error f δ [Procedure for obtaining a relationship] Figure 6 shows the frequency f of the reference power supply 6, obtained using equation 9, the required settings, and the measured values. test (Horizontal axis) and error f δ This figure shows the relationship with (vertical axis). As will be explained in detail later, power supply unit 2 uses the relationship shown in Figure 6 to control the actual frequency f out This can improve accuracy.

[0070] In Figure 6, the error f δ When the power supply unit 5 is connected to the power system 1, the frequency of the power system 1 is f test The actual frequency f when a steady state is reached. out This is the error that is included.

[0071] Below, using the measurement system 4 for measuring the error shown in Figures 4 and 5, the frequency f of the reference power supply 6 in this embodiment is measured. test And, error f δ This explains the procedure for obtaining the relationship.

[0072] First, the amplitude value of the output voltage of the reference power supply 6 and the output voltage v of the output unit 20. out The command value of the amplitude is set to a predetermined amplitude value V of the same value. ref Set to this.

[0073] Next, the inertia constant H in the GFM control system is set to the minimum value within the settable range. Also, the braking constant D is set to the maximum value within the settable range. The reason for these settings is as follows:

[0074] If the braking constant D is set to, for example, twice its original value, then the power P will be proportional to the braking constant D. out -P ref It also doubles. In other words, the braking constant D and the power P. out -P ref Since the ratio does not change, the error f δ It does not change. Therefore, the error f in number 9 δ The calculation formula includes the braking constant D, but the error f δ This does not depend on the braking constant D.

[0075] Power P according to the braking constant D out When it increases, power P out Measurement becomes easier and measurement accuracy improves. Then, power P in equation 9 out -P ref The accuracy of the error f has improved. δ The accuracy of this also improves. Note that these settings are arbitrary, and there are no restrictions on the inertia constant H and braking constant D in the method of checking the error.

[0076] Next, the target power P is input and output to power system 1. ref Set it to 0. In other words, the error f shown in equation 9. δ This can be rewritten as follows:

number

[0077] Next, the power supply unit 5 is connected to the reference power supply 6 and operated, and after a sufficient amount of time has elapsed and it has settled into a steady state, the power P out The actual measured value is taken. At this time, the frequency f of the reference power supply 6 is measured. test It is fixed to a predetermined value.

[0078] Next, Power P out The measured value and the rated frequency f of power system 1 n Substituting the damping constant D into equation 10, the frequency f of the fixed reference power supply 6 is obtained. test summer error f δ To obtain.

[0079] The above procedure is performed at the frequency f of the reference power supply 6. test Regarding the predetermined lower limit f min From the upper limit f max Up to a predetermined interval Δf, error f δ This yields the calculated value of the frequency f of the reference power supply 6 shown in Figure 6. test And, error f δ You can establish a relationship with this.

[0080] At this time, the lower limit f min and upper limit f max This refers to the rated frequency f of power system 1 between these points. n It is set to include the rated frequency f of power system 1. n When the frequency is 50[Hz], the lower limit f min For example, 45 [Hz], upper limit f max For example, it can be set to 55[Hz].

[0081] <<Power supply 2>> Figure 7 is a diagram illustrating the power supply unit 2 of this embodiment. The power supply unit 2 has a frequency f of the reference power supply 6 shown in Figure 6. test And, error f δ Based on the relationship, the output voltage v out The actual frequency f out This is a power supply unit 2 capable of improving accuracy.

[0082] The power supply unit 2 comprises a control unit 3 and an output unit 20. Since the hardware configuration of the control unit 3 is the same as that of the control unit 7 of the general power supply unit 5 described above, a detailed explanation of it will be omitted.

[0083] <Functional blocks of power supply unit 2> In this embodiment, as a result of the DSP35 executing a predetermined program, the control device 3 is configured with a calculation unit 30, a correction unit 31, an integrator 32, an instantaneous voltage control unit 33, and a PWM pulse generation unit 34.

[0084] As a result, the power supply unit 2 comprises a calculation unit 30, a correction unit 31, an integrator 32, an instantaneous voltage control unit 33, a PWM pulse generation unit 34, and an output unit 20.

[0085] Furthermore, the integrator 32, the instantaneous voltage control unit 33, and the PWM pulse generation unit 34 combined constitute the "generation unit." In other words, the "generation unit" generates the output voltage v based on the corrected command frequency. out Generates control signals to control the system.

[0086] Here, the calculation unit 30, the correction unit 31, the integrator 32, the instantaneous voltage control unit 33, the PWM pulse generation unit 34, and the output unit 20 each have the same configuration as those of the general power supply unit 5 described above, so their explanations will be omitted below.

[0087] In other words, power supply unit 2 differs from a typical power supply unit 5 in that it also includes a correction unit 31. The correction unit 31 will be described in detail below.

[0088] [Correction Unit 31] The correction unit 31 controls the command frequency f ref The correction unit 31 corrects the command frequency f, which is the output of the calculation unit 30. ref The input is used, and the corrected command frequency is output to the integrator 32.

[0089] The correction unit 31 controls the command frequency f ref The reason for correcting this is, as mentioned above, in a typical power supply unit 5, the output voltage v output from the output unit 20 is out The actual frequency f out The command frequency f ref This does not happen, and the command frequency f ref For error f δ This may include the frequency f.out However, such an error f δ As mentioned above, including this, the target power P for input and output is ref And the power P that is actually input and output. out The two diverge.

[0090] In the following explanation, the command frequency f output by the calculation unit 30 is used. ref "The command frequency f before correction" ref It may be referred to as "command frequency f". Also, the command frequency output by the correction unit 31 through the process described later is referred to as the "corrected command frequency". Unless otherwise specified, it will simply be referred to as "command frequency f". ref When referring to this, the command frequency f before correction is used. ref This is what it means.

[0091] In this embodiment, the power supply unit 2 is described as "actual frequency f out "Accuracy" refers to the command frequency f before correction. ref Output voltage v out The actual frequency f out The accuracy is set to this value. In other words, the output voltage v out The actual frequency f out However, the command frequency f before correction ref The closer it is to the frequency f out Its accuracy is high.

[0092] The correction unit 31 controls the power P ref And, Power P out The command frequency f such that it matches in the steady state. ref This corrects the command frequency f obtained in the steady state before correction. Specifically, the correction unit 31 corrects the command frequency f obtained in the steady state before correction. ref And the output voltage v out The actual frequency f out Error f δ Based on this, the command frequency f ref Correct it.

[0093] The correction unit 31 controls the output voltage v out The actual frequency f out However, the command frequency f before correction ref The command frequency f before correction is set to match this.ref Correct it.

[0094] In this embodiment, the correction unit 31 controls the command frequency f before correction. ref And, error f δ Using a data table (corresponding to "table") that shows the relationship, the command frequency f before correction is used. ref Correct the error f in this data table. δ " means "error f δ This is an example of "information that includes".

[0095] A "data table" is data that shows the relationship between one type of data and another type of data. A data table may be presented in the form of a graph or a table.

[0096] Figure 9 shows the command frequency before correction (horizontal axis) and the error f. δ This figure shows an example of data table T1, which illustrates the relationship with the vertical axis. Data table T1 is presented in graph format.

[0097] In Figure 9, the command frequency f ref The domain is a predetermined lower limit f min From a predetermined upper limit f max It is up to this point.

[0098] Data table T1 shows the frequency f of the reference power supply 6 shown in Figure 6. test And the output voltage v out The actual frequency f out Error f δ In relation to this, the horizontal axis represents the command frequency f before correction. ref This is a replacement.

[0099] In other words, this data table T1 is prepared in advance based on the verification method described above and is stored in the memory 36a of the storage device 36.

[0100] The correction unit 31 uses this data table T1 to determine the command frequency f before correction.ref For error f δ Perform a process to reduce it.

[0101] Specifically, the correction unit 31 of this embodiment has an adder 310 (Figure 8). The adder 310 receives the command frequency f before correction output from the calculation unit 30. ref And the error f output from memory 36a contained in the storage device 36 δ The following is entered.

[0102] The adder 310 uses the command frequency f before correction. ref Therefore, error f δ The process of subtracting is performed. In other words, the adder 310 uses frequency f as the corrected command frequency. ref -f δ Outputs.

[0103] Here, the error f output by memory 36a δ This is determined by the data table T1 in Figure 9 and is the uncorrected command frequency f, which is the input from the calculation unit 30. ref Error f corresponding to the value δ That is the case.

[0104] The correction unit 31 corrects the command frequency f ref -f δ When this is output, the corrected command frequency f ref -f δ The integrator 32, instantaneous voltage control unit 33, and PWM pulse generation unit 34 then perform processing.

[0105] These processes (especially the PWM pulse generation unit 34) correct the command frequency f ref -f δ In contrast, the error f reduced in the correction unit 31 δ The same amount of error f δ This is added. In other words, the PWM pulse generation unit 34 uses the command frequency f before correction. ref Equivalent frequency f ref This is output to the output unit 20.

[0106] Based on the above, the output unit 20 has a command frequency f before correction.ref Equivalent frequency f ref Output voltage v out This is output to power system 1. In other words, the command frequency f output by the calculation unit 30. ref And the output voltage v out The actual frequency f out This is equivalent to (f ref ) and the actual frequency f out The accuracy of the error f improves. δ (=f out -f ref ) can be set to 0.

[0107] Furthermore, the actual frequency f out As a result of improved accuracy, the target power P input and output to power system 1 is ref And the power P that is actually input and output to power system 1. out The discrepancy with this is suppressed.

[0108] This means that the error f on the left side in equation 9 δ If is 0, then P on the right side out -P ref This is because it can be derived that the result is 0.

[0109] Equation 9 was derived using the measurement system 4 shown in Figures 4 and 5. Equation 9 also holds true if the measurement system 4 uses a power supply 2 that further includes the correction unit 31 of this embodiment, instead of a general power supply 5.

[0110] This is because, in the derivation of equation 9, the processing from the calculation unit 30 in Figure 4 to the PWM pulse generation unit 34 does not need to be considered, and in fact, these processes are not considered. Therefore, equation 9 holds true regardless of the presence or absence of the correction unit 31.

[0111] Note that the error f at this time δ (=f out -f ref ) in the command frequency f ref This is the command frequency f before correction. ref That is the case.

[0112] As explained above, according to the power supply device 2 of this embodiment, the output voltage v out The actual frequency f out This makes it possible to improve the accuracy of the measurement.

[0113] In this embodiment, the correction unit 31 uses the data table T1 to determine the command frequency f ref We decided to correct this, but it is not limited to this.

[0114] For example, instead of data table T1, the command frequency f before correction can be used. ref And, error f δ A relational expression showing the relationship may also be used. In this case, the relational expression would be: for data table T1, the lower limit f min From the upper limit f max Over the period, error f δ The value of may be approximated or interpolated by, for example, a linear or multi-degree polynomial.

[0115] ==Variation 1== The power supply unit of this modified example will now be described. The power supply unit of this modified example differs from the power supply unit 2 of the embodiment in that the processing performed by the correction unit 31 is different. The correction unit 31 of this modified example uses the data table T2 shown in Figure 10 instead of the data table T1 (Figure 9).

[0116] Data table T2 shows the command frequency f before correction. ref This data table shows the relationship between the (horizontal axis) and the corrected command frequency f (vertical axis). In this data table T2, "corrected command frequency f" refers to the command frequency f before correction. ref For error f δ The value after subtraction (f ref -f δ )

[0117] Note that in this data table T2, "corrected command frequency" refers to "error f δ This is another example of the above embodiment of "information including".

[0118] The correction unit in this modified example uses the command frequency f before correction.ref The process is executed to replace it with the corrected command frequency f.

[0119] In other words, the correction unit of this modified example, like the correction unit 31 of the embodiment, corrects the command frequency f ref -f δ This outputs the following. Then, the processing from the integrator 32 onward is the same as in the embodiment described above.

[0120] Therefore, even in this modified form, the output unit 20 controls the command frequency f before correction. ref Equivalent frequency f ref Output voltage v out This is output to power system 1. In other words, the command frequency f output by the calculation unit 30. ref And the output voltage v out The actual frequency f out Equivalent to (f ref ) and the actual frequency f out The accuracy will improve.

[0121] Furthermore, the actual frequency f out As a result of improved accuracy, the target power P input and output to power system 1 is ref And the power P that is actually input and output to power system 1. out The discrepancy with this is suppressed.

[0122] Even in the embodiments described above, according to the power supply device of this modified example, the output voltage v out The actual frequency f out This makes it possible to improve the accuracy of the measurement.

[0123] ==Variation 2== In this embodiment, when preparing the data table T1, the error f shown in Equation 9 is used. δ Substitute the necessary set values ​​and measured values ​​into the calculation formula and obtain the error f δ I obtained it.

[0124] Instead, error f δ This refers to the command frequency f in the steady state when the power supply unit 5 is connected to the reference power supply 6. refThe measured value and the frequency f of the reference power supply 6 test It may also be determined by the difference between the two (see the following equation).

number

[0125] Here, the first term on the right-hand side is the frequency f of the reference power supply 6. test This is the setting value, and the second term on the right-hand side is the command frequency f ref These are the measured values.

[0126] Command frequency f ref To obtain the measured value, for example, the power supply unit 5 is connected to the command frequency f, which is the output of the calculation unit 30. ref A measuring unit may be added to measure the calculated command frequency f. Alternatively, the calculation unit 30 may measure the calculated command frequency f. ref The value may also be output to memory 36a.

[0127] Even in the embodiments described above, according to the power supply device of this modified example, the output voltage v out The actual frequency f out This makes it possible to improve the accuracy of the measurement.

[0128] ==Summary== In summary, the power supply device 2 of the embodiment has an output voltage v out A power supply device that inputs and outputs power to and from a power system 1 by controlling the frequency of a target power P to be output to the power system 1. ref And the power P that is actually input and output to power system 1. out And the predetermined set frequency f n,ref Based on this, the output voltage v out Command frequency f ref A calculation unit 30 that calculates the command frequency f ref A correction unit 31 corrects the output voltage v based on the corrected command frequency. out A generation unit that generates a control signal to control the system, and an output voltage v generated based on the control signal. out The system includes an output unit that outputs to the power system 1, and the correction unit 31 controls the power P ref And, Power P outThe command frequency f obtained in the steady state, before correction, is used so that it matches in the steady state. ref And the output voltage v out The actual frequency f out Error f δ Based on the command frequency f ref Correct it.

[0129] With this configuration, the output voltage v out The actual frequency f out This provides a power supply device 2 that can improve the accuracy of the device.

[0130] In the power supply device 2 of this embodiment, the correction unit 31 controls the output voltage v out The actual frequency f out However, the command frequency f before correction ref The command frequency f before correction is set to match this. ref And, error f δ Using a pre-prepared table or relational expression that shows the relationship with the information including the command frequency f ref This corrects the command frequency f before correction. With this configuration, the command frequency f before correction is corrected. ref And, using only tables or relational expressions, the command frequency f ref This can correct the error f in real time when connecting to the power system 1. δ Since there is no need to calculate it, the cost of calculation can be reduced.

[0131] In the power supply device 2 of the embodiment, error f δ Information including error f δ The correction unit 31 adjusts the command frequency f before correction. ref For error f δ A process is executed to reduce the error f with respect to the corrected command frequency. δ Output voltage v of the command frequency with added values out However, it is output from the output unit. In other words, the correction unit 31 corrects the error f of the command frequency. δ The command frequency f before correction is corrected so that the two effects cancel each other out. ref To correct this, the output voltage v outThe actual frequency f out is the command frequency f before correction ref .

[0132] In the power supply device of Modification 1, the information including the error f δ is the corrected command frequency with the error f ref subtracted from the command frequency f before correction δ . The correction unit 31 executes a process of replacing the command frequency f before correction ref with the corrected command frequency. According to such a configuration, the output voltage v δ of the command frequency with the error f out added thereto is output from the output unit. That is, the correction unit 31 corrects the command frequency f before correction δ so that the error f ref is canceled out. Therefore, the actual frequency f out of the output voltage v out is the command frequency f before correction ref .

[0133] In the power supply device 2 of the embodiment, the error f δ is determined as the calculated value of the difference between the command frequency f ref and the frequency f test of the reference power supply 6 in the steady state when the power supply device 5 including the calculation unit 30, the generation unit, and the output unit is associated with the reference power supply 6 whose frequency can be controlled. According to such a configuration, by using the calculation formula of the difference between the command frequency f ref and the frequency f test of the reference power supply 6, the error f δ can be accurately obtained.

[0134] In the power supply device 2 of the embodiment, the error f δ is determined as the difference between the measured value of the command frequency f ref and the frequency f test of the reference power supply 6 in the steady state when the power supply device 5 including the calculation unit 30 and the output unit is associated with the reference power supply 6 whose frequency can be controlled. According to such a configuration, by using the definition of the direct error f δ , the error f δ can be easily obtained.can be obtained.

[0135] In the voltage generation method of the embodiment, a power supply device 2 that inputs and outputs power to and from the power grid 1 by controlling the frequency of the voltage outputs a target power P to the power grid 1 ref and the power P actually input and output to the power grid 1 out and a predetermined set frequency f n,ref Based on this, a command frequency f for the output voltage v out is calculated, the command frequency f ref is corrected, and based on the corrected command frequency, a control signal for controlling the output voltage v ref is generated, and the output voltage v out generated based on the control signal is output to the power grid 1. In the correction step, the power P out and the power P ref are made to match in the steady state. Based on the error f between the command frequency f out before correction obtained in the steady state and the actual frequency f ref of the output voltage v out the command frequency f out is corrected. δ ref out

[0136] According to such a method, a voltage generation method capable of improving the accuracy of the actual frequency f out of the output voltage v out can be provided.

Explanation of Signs

[0137] Power grid 1 Power supply device 2 Output unit 20 DC power supply 200 Control device 3 Calculation unit 30 Correction unit 31 Integrator 32 [[ID=6y]] Instantaneous voltage control unit 33 PWM pulse generation unit 34 DSP 35 storage device 36 Measurement system 4 power supply 5 Reference power supply 6 Control device 7

Claims

1. A power supply device that inputs and outputs power to and from a power system by controlling the frequency of the output voltage, A calculation unit that calculates a command frequency for the output voltage based on a target first power to be output to the power system, a second power actually input and output to the power system, and a predetermined set frequency. A correction unit for correcting the command frequency, A generation unit that generates a control signal for controlling the output voltage based on the corrected command frequency, An output unit that outputs the output voltage generated based on the control signal to the power system. Equipped with, The correction unit, The command frequency is corrected based on the error between the command frequency before correction and the actual frequency of the output voltage, obtained in a steady state, so that the first power and the second power coincide in a steady state. power supply.

2. A power supply device according to claim 1, The correction unit corrects the command frequency using a pre-prepared table or relational expression that shows the relationship between the command frequency before correction and the information including the error, so that the actual frequency of the output voltage matches the command frequency before correction. power supply.

3. A power supply device according to claim 2, The information including the aforementioned error is the aforementioned error, The correction unit performs a process to reduce the error with respect to the command frequency before correction. power supply.

4. A power supply device according to claim 2, The information including the error is the corrected command frequency obtained by reducing the error compared to the command frequency before correction. The correction unit performs a process to replace the command frequency before correction with the command frequency after correction. power supply.

5. A power supply device according to any one of claims 1 to 4, The error is determined by the calculated difference between the command frequency and the frequency of the reference power supply in a steady state when the power supply device, including the calculation unit and the output unit, is connected to a reference power supply with a controllable frequency. power supply.

6. A power supply device according to any one of claims 1 to 4, The aforementioned error is determined by the difference between the measured value of the command frequency and the frequency of the reference power supply in a steady state when the power supply device, including the calculation unit and the output unit, is connected to a reference power supply capable of controlling frequency. power supply.

7. A power supply device that inputs and outputs power to and from the power system by controlling the frequency of the output voltage, A step of calculating a command frequency for the output voltage based on a target first power to be output to the power system, a second power actually input and output to the power system, and a predetermined set frequency. The steps of correcting the command frequency, The steps include generating a control signal for controlling the output voltage based on the corrected command frequency, The steps include outputting the output voltage generated based on the control signal to the power system, and Includes, In the correction step, The command frequency is corrected based on the error between the command frequency before correction and the actual frequency of the output voltage, obtained in a steady state, so that the first power and the second power coincide in a steady state. Voltage generation method.

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