WO2019092812A1

WO2019092812A1 - Control device, control method, and program

Info

Publication number: WO2019092812A1
Application number: PCT/JP2017/040277
Authority: WO
Inventors: 喜仁木下; 伸也直井; 崇裕石黒
Original assignee: 株式会社東芝; 東芝エネルギーシステムズ株式会社
Priority date: 2017-11-08
Filing date: 2017-11-08
Publication date: 2019-05-16
Also published as: JPWO2019092812A1; JP6977056B2

Abstract

The control device according to an embodiment is a control device for a self-commutated converter connected to an AC system. The control device has a filter calculation unit, a coordinate transformation unit, and a converter control unit. The filter calculation unit calculates, on the basis of the voltage of each of the three phases of the AC system, a current target value for each of the three phases so as to obtain a transfer function based on the RLC components of an AC filter capable of suppressing the harmonics of a predetermined frequency band. The coordinate transformation unit transforms the current target value for each of the three phases calculated by the filter calculation unit to a first d-axis current target value and a first q-axis current target value. The converter control unit controls the self-commutated converter on the basis of a second d-axis current target value based on requested power and the first d-axis and q-axis current target values transformed by the coordinate transformation unit.

Description

Control device, control method, and program

Embodiments of the present invention relate to a control device, a control method, and a program.

Introduction of DC power transmission is in progress. DC power transmission has advantages such as rapid power flow control and suitable for long distance power transmission and cable power transmission. In DC power transmission, a power converter that converts power from direct current to alternating current or from alternating current to direct current is provided at both ends of the direct current link.

Conventionally, a separately excited converter in which a thyristor is applied to a switching element has often been used in a power conversion device used for DC power transmission. In recent years, the introduction of a self-excited converter has been promoted because of its excellent controllability and the possibility of downsizing of equipment.

In the self-excitation converter, when converting alternating current power from an alternating current system into direct current power, an alternating current voltage is output such that arbitrary alternating current power flows from the alternating current system. This alternating voltage can be output arbitrarily.

On the other hand, in the separately excited converter, when converting power from alternating current to direct current, harmonic current causing voltage distortion is generated, or the separately excited converter consumes reactive power to lower the grid voltage. May be For this reason, when using a general separately excited converter, an AC filter for absorbing harmonic current and compensating reactive power is connected to the AC system. If the AC filter fails, voltage distortion of the AC system and voltage drop of the AC system may occur. When the separately excited converter is stopped, the AC filter may generate reactive power, whereby an overvoltage may occur in the AC system.

Related to these, the voltage distortion component is extracted by applying a high-pass filter to a value obtained by applying dq coordinate conversion that converts the fundamental frequency component to a DC component to the voltage of the AC system, thereby extracting the voltage distortion component. A first technique is known in which a value obtained by multiplying the component of the coefficient by a factor is used as a command value of the current controller. In the first technique, the self-excited converter operates to flow harmonic currents that suppress voltage distortion, and can suppress voltage distortion of the grid.

A second technology is known that includes two converters, adjusts the phase and outputs a voltage so as to cancel one of the voltage distortions, thereby mutually canceling the voltage distortions and suppressing the occurrence of the voltage distortions. ing.

In the first technique, processing is performed on voltage distortions of all frequency bands, and therefore, it may not be possible to effectively suppress a specific frequency or a harmonic of a specific order. In the second technology, power conversion devices that generate the same voltage distortion need to be adjacent, and the application scene is limited.

JP, 2015-204684, A

Problem to be solved by the invention is providing the control apparatus which can suppress the harmonic of a predetermined frequency band effectively using a self-excitation converter, and a control method.

The control device of the embodiment is a control device of a self-excitation converter connected to an AC system. The control device has a filter operation unit, a coordinate conversion unit, and a converter control unit. The filter operation unit sets the current target value for each of the three phases based on the voltage for each of the three phases of the AC system so as to realize a transfer function based on the RLC component of the AC filter capable of suppressing harmonics in a predetermined frequency band. calculate. The coordinate conversion unit converts the current target values for each of the three phases calculated by the filter operation unit into a first d-axis current target value and a first q-axis current target value. The converter control unit performs the self-excitation converter based on the second d-axis current target value based on the required power and the first d-axis current target value and the first q-axis current target value converted by the coordinate conversion unit. Control.

The figure which shows the 1st application scene of the power converter device 100 which concerns on 1st Embodiment. The figure which shows the 2nd application scene of the power converter device 100 which concerns on 1st Embodiment. BRIEF DESCRIPTION OF THE DRAWINGS The block diagram of the power converter device 100 which concerns on 1st Embodiment. 5 is a flowchart showing an example of the flow of processing executed by a filter operation unit 142. 5 is a flowchart showing an example of the flow of processing executed by an in-accident reactive power output control unit 154 of the voltage compensation control unit 150; The block diagram of power converter 100A containing control device 120A concerning a 2nd embodiment. The figure which shows an example of the hardware constitutions of

control apparatus

120 or 120A of each embodiment.

Hereinafter, a control device, a control method, and a program of the embodiment will be described with reference to the drawings. In the drawings, the power lines of the three phases are not shown separately but are represented by single lines. Also, each of the three phases is represented by the symbols a, b and c.

First Embodiment
[Application scene]
First, with reference to FIG. 1 and FIG. 2, the application scene of the power converter device containing a control apparatus is demonstrated. In addition, in FIG. 1 and FIG. 2, illustration is abbreviate | omitted about the direct current | flow side of each power converter device. FIG. 1 is a diagram showing a first application scene of the power conversion device 100 according to the first embodiment. As illustrated, the power conversion device 100 including a self-excitation converter is connected to the bus 2 of the AC system 1 in parallel with the power conversion device 10 including a separately excited converter. The separately excited converter is a converter that requires an AC voltage of an AC system when turning on / off current. Further, one or more AC filters 20-1, 20-2,..., 20-n are connected to the bus bar 2 (n is an arbitrary natural number). When it does not distinguish which AC filter is used, it is simply referred to as the AC filter 20. After the operation is started in this state, for example, when the AC filter 20-2 fails, the power conversion apparatus 100 operates an active filter of a frequency band corresponding to the AC filter 20-2. Further, power conversion device 100 may perform voltage compensation control corresponding to AC filter 20-2. The function of the power conversion device 100 can be applied not only to the failure of the AC filter 20 but also to the case where the AC filter 20 is temporarily stopped for inspection or the like.

FIG. 2 is a diagram showing a second application scene of the power conversion device 100 according to the first embodiment. The connection relationship is the same as that shown in FIG. In this scene, for example, it is determined that the AC filters 20-2 and 20-n are eliminated before the operation is started. In this case, power conversion device 100 starts operation with active filters of frequency bands corresponding to AC filters 20-2 and 20-n. If one of the AC filters 20 breaks down after the start of operation, the power conversion apparatus 100 may activate an active filter of a frequency band corresponding to the broken AC filter 20 as in the first use scene.

[Constitution]
FIG. 3 is a block diagram of the power conversion device 100 according to the first embodiment. Power converter 100 includes a self-excited converter 110 and a controller 120 that controls self-excited converter 110.

The self-excited converter 110 mutually converts direct current and alternating current. The AC side of the self-excited converter 110 is connected to the bus 2, and the DC side is connected to a DC system (not shown). The self-excitation converter 110 is a converter using a self-arc-extinguishing element. The self-excited converter 110 has a current interrupting capability, and can be operated regardless of the AC voltage on the AC system side. As a self arc-extinguishing element, for example, an IGBT (Insulated Gate Bipolar Transistor) or an IEGT (Injection Enhanced Gate Transistor), which is a voltage drive self-arc-extinguishing element, is used. Self-excitation converter 110 performs switching operation based on voltage command values Vcov_a, Vcov_b, and Vcov_c for each of the three phases input from control device 120 to convert direct current and alternating current mutually.

For example, system voltages Va, Vb, and Vc for each of the three phases detected by the voltage detector 30 attached to the bus 2 are input to the control device 120.

The control device 120 includes, for example, a target value calculation unit 130, a filter unit 140, a voltage compensation control unit 150, and a converter control unit 160. These components are realized, for example, by execution of a program (software) by a hardware processor such as a central processing unit (CPU). In addition, some or all of these components may be hardware (circuits) such as LSI (Large Scale Integration), ASIC (Application Specific Integrated Circuit), FPGA (Field-Programmable Gate Array), GPU (Graphics Processing Unit), etc. Circuit (including circuitry) or may be realized by cooperation of software and hardware.

The target value calculation unit 130 calculates the d-axis current target value Idref based on the required power input from the higher-level device (not shown). The d-axis is a virtual coordinate axis representing active power. Further, the q-axis described later is a virtual coordinate axis representing reactive power. The d-axis current target value Idref is an example of a second d-axis current target value.

The filter unit 140 includes, for example, a filter operation unit 142, a coordinate conversion unit 144, and HPF (high pass filter)

units

146d and 146q.

The filter operation unit 142 has a transfer function based on an RLC component of an AC filter capable of suppressing harmonics in a predetermined frequency band based on the grid voltages Va, Vb and Vc for each of the three phases input from the voltage detector 30. As realized, the current target value for each of the three phases is calculated. The harmonic of the predetermined frequency band is, as described with reference to FIG. 1 or FIG. 2, a harmonic of a frequency band suppressed by the broken AC filter 20 or the ac filter 20 to be abolished. The filter calculation unit 142 calculates the current target value for each of the three phases for the self-excitation converter 110 to substitute the function of the AC filter 20. Hereinafter, the AC filter 20 whose function is replaced by the self-excited converter 110 is referred to as a virtual filter.

Here, it demonstrates paying attention to one phase among three phases. The AC filter 20 is often an electric circuit in which a resistor R, an inductance L, and a capacitor C are connected in series (hereinafter, referred to as an RLC series circuit) or an electric circuit in which a plurality of RLC series circuits are connected in parallel. Then, assuming that the virtual filter is an RLC series circuit (or a circuit approximated to this), the electric circuit equation of the virtual filter is the size of each of resistance R, inductance L and capacitor C (RLC component) It is represented by Formula (1) using.

Laplace transform of Equation (1) using the Laplace operator s yields a transfer function Fil (s) having the same specification as the RLC serial circuit, as shown in Equation (2). That is, it is Fil (s) = (R + Ls + 1 / Cs).

Furthermore, assuming that the virtual filter is a circuit in which a plurality of RLC series circuits are connected in parallel, the transfer function Fil _all (s) of the entire virtual filter is expressed by equation (3). In the formula, Fil ₁ (s), Fil ₂ (s),... Fil _n (s) represent transfer functions of respective RLC DC circuits connected in parallel in the virtual filter. n is an arbitrary natural number, and n may be 1.

Filter calculation unit 142, by applying the time domain the inverse of the transfer function _{Fil all} virtual filter (s), and calculates the higher harmonic current i flowing through the virtual filter (t) from the AC voltage V (t). By performing this for each of the three phases, the filter operation unit 142 calculates the current target values Iaf, Ibf, and Icf for each of the three phases based on the grid voltages Va, Vb, and Vc for each of the three phases.

The coordinate conversion unit 144 converts the current target values Iaf, Ibf and Icf for each of the three phases calculated by the filter operation unit 142 into a d-axis current target value Idf # and a q-axis current target value Iqf #. There is no particular limitation on the conversion method of the coordinate conversion unit 144, and the coordinate conversion unit 144 performs the above conversion by, for example, a known method. The d-axis current target value Idf # is an example of a first d-axis current target value, and the q-axis current target value Iqf # is an example of a first q-axis current target value. In this process, the fundamental frequency component in the AC system is converted to a DC component.

The HPF unit 146 d removes low frequency components including direct current components from the d axis current target value Idf #. The HPF unit 146 q removes low frequency components including direct current components from the q-axis current target value Iqf #. As a result, fundamental frequency components in the AC system are removed. The HPF unit 146 d outputs the d-axis current target value Idref #, and the HPF unit 146 q outputs the q-axis current target value Iqref #. These current target values are components for realizing the function of the virtual filter among the current target values of the self-excited converter 110.

The voltage compensation control unit 150 includes, for example, a constant voltage control unit 152, a reactive power output control unit 154 in case of an accident, and a constant reactive power control unit 156.

The constant voltage control unit 152 calculates the reactive power target value Qv_ref for maintaining the voltage of the AC system constant based on the system voltages Va, Vb and Vc for each of the three phases detected by the voltage detector 30. .

The in-accident reactive power output control unit 154 outputs a reactive power target value Qcon_ref for bringing the reactive power closer to a desired value more quickly than the constant voltage control unit 152 when the following predetermined conditions are satisfied.

(1) At the time of accident reactive power output control unit 154 selects one of current target values Iaf, Ibf and Icf for each of the three phases output from filter operation unit 142, an average value or an effective value or other statistical values, or Reactive power target value Qcon_ref when all are equal to or higher than the threshold value, and any of grid voltage Va, Vb and Vc, average value, effective value or other statistical value, or all falls below the first reference value Output The effective value is a value obtained by finding the square of each sum of squares. The first reference value is set based on, for example, a voltage drop that occurs when the AC filter 20 fails. Therefore, these conditions are satisfied, for example, when a failure occurs in the AC filter 20. As a result of the above control, the system voltage can be raised to a desired value, and the influence of the failure of the AC filter 20 can be reduced.

(2) At the time of accident reactive power output control unit 154 reduces any of grid voltage Va, Vb and Vc, average value, effective value and other statistical values or all or more to the second reference value or more, Also when the voltage recovers, the reactive power target value Qcon_ref is output. The second reference value is set on the basis of the voltage drop at which the separately excited converter stops. For example, it is 1st standard value <2nd standard value. The term "recovered" means, for example, that the state before the reduction of the system voltage has been reached or expected to be reached after a predetermined time. As a result of the above control, since the reactive power consumed by the stopped separately excited converter can be consumed by the self-excited converter 110, the system voltage is reduced to a desired value to stop the separately excited converter. The impact can be reduced.

The reactive power target value Qref obtained by adding the reactive power target value Qv_ref output by the constant voltage control unit 152 and the reactive power target value Qcon_ref output by the reactive power output control unit 154 is a constant reactive power control unit It is input to 156. Constant reactive power control unit 156 calculates and outputs q-axis current target value Iqref for bringing reactive power in bus 2 closer to reactive power target value Qref. The constant voltage control unit 152 and the constant reactive power control unit 156 perform feedback control such as PID control, for example.

The d-axis current target value Idref output by the target value calculation unit 130 is added to the d-axis current target value Idref # output by the HPF unit 146 d, and is converted to the final d-axis current target value Id *. Is input to The q-axis current target value Iqref # output by the HPF unit 146q is added to the q-axis current target value Iqref output by the constant reactive power control unit 156, and converted as a final q-axis current target value Iq *. It is input to 160. Converter control unit 160 sets voltage command values Vcov_a, Vcov_b for each of three phases to be applied to self-exciting converter 110 based on input final d-axis current target value Id * and final q-axis current target value Iq *. Vcov_c is calculated and output to the self-excited converter 110.

[Processing flow etc.]
The function of the filter operation unit 142 will be described again. Information on the RLC component of the AC filter 20 (virtual filter) is stored in advance in the storage device of the control device 120. The filter operation unit 142 calculates Fil _k (s) based on the RLC component of the virtual filter k that needs to be realized, and obtains Fil _all (s).

FIG. 4 is a flowchart showing an example of the flow of processing executed by the filter operation unit 142. First, the filter operation unit 142 determines whether an instruction to add a virtual filter has been received (step S100). The instruction to add the virtual filter may be received via, for example, an input unit (mouse, keyboard, touch panel, etc.) (not shown) of the control device 120, or may be received from another device through communication.

When an instruction to add a virtual filter is received, the filter operation unit 142 acquires the transfer function of the virtual filter k related to the addition instruction (step S102). k is a variable for identifying a virtual filter. The filter operation unit 142 may obtain the transfer function of the virtual filter k by obtaining the RLC component of the virtual filter and performing the calculation of Equation (2), or directly obtaining the parameters of the transfer function. Alternatively, the information on the transfer function of the virtual filter k stored in advance in the storage device may be read out.

Next, the filter operation unit 142 recalculates the transfer function Fil _all (s) of the entire virtual filter by reflecting the transfer function of the virtual filter k acquired in step S102 (step S104). As a result of the recalculation, the transfer function Fil _all (s) of the entire virtual filter reflects the transfer function of the virtual filters 1 to k (see equation (3)). The filter operation unit 142 increments the variable by 1 for the next calculation (step S106).

Then, the filter operation unit 142 executes the filter operation using the transfer function Fil _all (s) of the entire virtual filter (step S108). The filter operation unit 142 repeatedly executes such processing.

FIG. 5 is a flow chart showing an example of the flow of processing executed by the reactive power output control unit 154 in case of a fault of the voltage compensation control unit 150. First, the in-accident reactive power output control unit 154 determines whether the first condition is satisfied (step S200). As described above, the first condition is any one of the current target values Iaf, Ibf, and Icf for each of the three phases output by the filter operation unit 142, an average value, an effective value, or any other statistical value, or all of them. Is equal to or higher than the threshold value, and any of the system voltages Va, Vb, and Vc, the average value, the effective value or any other statistical value, or all is lowered by the first reference value or more. If it is determined that the first condition is satisfied, the reactive power output control unit 154 outputs the reactive power target value Qcon_ref (step S204).

Further, the in-accident reactive power output control unit 154 determines whether the second condition is satisfied (step S202). The second condition is that, as described above, any of the system voltages Va, Vb and Vc, the average value, the effective value and other statistical values, or all of them decrease by the second reference value or more, and then the system voltage Has recovered. Also in the case where it is determined that the second condition is satisfied, the in-accident reactive power output control unit 154 outputs the reactive power target value Qcon_ref (step S204).

According to the control device 120 according to the first embodiment described above and the control method executed by the control device 120, a transfer function based on the RLC component of the AC filter capable of suppressing harmonics in a predetermined frequency band is realized To calculate the current target value for each of the three phases based on the voltage for each of the three phases of the AC system, and the calculated target current value for each of the three phases as the 1st d axis current target value and the 1 q axis current By converting to the target value and controlling the self-excited converter 110 based on the second d-axis current target value based on the required power and the converted first d-axis current target value and the first q-axis current target value, The self-excitation converter 110 can be used to effectively suppress harmonics in a predetermined frequency band.

Second Embodiment
The second embodiment will be described below. In the power conversion device 100A according to the second embodiment, one or more self-excited converters 110 are connected to a power system, and a power conversion device 10 including an externally excited converter and an AC filter 20 are connected to the power system. Applies to scenes that are not

FIG. 6 is a block diagram of a power conversion device 100A including a control device 120A according to the second embodiment. As illustrated, the control device 120A has a configuration in which the voltage compensation control unit 150 is omitted from the control device 120 according to the first embodiment. In the second embodiment, the value output by the HPF unit 146 q is input to the converter control unit 160 as the final q-axis current target value Iq *.

The filter operation unit 142A in the second embodiment performs the filter operation based on the RLC characteristic of the grid to which the self-excitation converter 110 is connected. The filter operation unit 142A calculates the harmonic current i (t) flowing through the virtual filter from the AC voltage V (t) by applying the reciprocal of the transfer function Fil _grid (s) of the virtual filter to the time domain. By performing this for each of the three phases, filter operation unit 142A calculates current target values Iaf, Ibf, and Icf for each of three phases based on grid voltages Va, Vb, and Vc for each of the three phases. Where m is the order of the harmonics.

Here, the transfer function Fil _grid (s) of the virtual filter is obtained as follows. First, impedance information of transmission lines, transformers and generators of the power system 1 is obtained, and an analysis model of the power system is constructed on the instantaneous value analysis software of the power system. At the connection point (grid) of the self-excitation converter of this model, the harmonic current in each order is injected and the generated harmonic voltage is calculated. The harmonic current, the harmonic voltage, and the impedance characteristic of the system have the relationship of the equation (4), and the transfer function Fil _grid (s) of the virtual filter is calculated from the injected harmonic current and the generated harmonic voltage. Can.

According to the control device 120A according to the second embodiment described above and the control method executed in this, the same effects as those of the first embodiment can be obtained.

Also in the second embodiment, the voltage compensation control unit 150 may be provided as in the first embodiment. In this case, the reactive power output control unit 154 of the voltage compensation control unit 150 outputs the reactive power set in advance when the harmonic current of the specific order becomes equal to or higher than the threshold and the system voltage decreases. You may do so.

[Hardware configuration]
FIG. 7 is a diagram showing an example of a hardware configuration of the

control device

120 or 120A (hereinafter, representatively referred to as control device 120) of each embodiment. As illustrated, the control device 120 includes a communication controller 120-1, a CPU 120-2, a RAM (Random Access Memory) 120-3 used as a working memory, and a ROM (Read Only Memory) 120 for storing a boot program and the like. 4. A storage device 120-5 such as a flash memory or a hard disk drive (HDD), a drive device 120-6, etc. are mutually connected by an internal bus or a dedicated communication line. The communication controller 120-1 communicates with other devices. The storage device 120-5 stores a program 120-5a executed by the CPU 120-2. This program is expanded on the RAM 120-3 by a DMA (Direct Memory Access) controller (not shown) or the like and executed by the CPU 120-2. Thereby, a part or all of the target value calculation unit 130, the filter unit 140, the voltage compensation control unit 150, and the converter control unit 160 is realized.

The above embodiment can be expressed as follows.
A control device for a self-excited converter connected to an alternating current system, the control device comprising:
A storage device for storing a program;
And a hardware processor,
The hardware processor executes the program to
In order to realize a transfer function based on the RLC component of an AC filter capable of suppressing harmonics in a predetermined frequency band, current target values for each of the three phases are calculated based on voltages for each of the three phases of the AC system,
Converting the current target values for each of the three phases calculated by the filter operation unit into a first d-axis current target value and a first q-axis current target value;
The self-excited converter is configured to be controlled based on a second d-axis current target value based on a required power, and a first d-axis current target value and a first q-axis current target value converted by the conversion unit. Yes,
Control device.

While certain embodiments of the present invention have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the invention. These embodiments can be implemented in other various forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the invention described in the claims and the equivalents thereof as well as included in the scope and the gist of the invention.

Claims

A control device for a self-excited converter connected to an alternating current system, the control device comprising:
A filter operation unit that calculates current target values for each of three phases based on voltages for each of the three phases of the AC system so as to realize a transfer function based on the RLC component of the AC filter capable of suppressing harmonics in a predetermined frequency band When,
A coordinate conversion unit for converting the current target values for each of the three phases calculated by the filter operation unit into a first d-axis current target value and a first q-axis current target value;
A converter control unit that controls the self-excited converter based on the second d-axis current target value based on the required power and the first d-axis current target value and the first q-axis current target value converted by the coordinate conversion unit. When,
Control device comprising:
And a voltage compensation control unit that causes the self-excitation converter to output a preset reactive power when a predetermined condition is satisfied.
The control device according to claim 1.
The predetermined condition is any one of the current target values for each of the three phases calculated by the filter operation unit, an average value, an effective value, and other statistical values, or all of them are equal to or more than a threshold value. Of any of the system voltage, average value, effective value and other statistical values, or all that have fallen by more than the first reference value,
The control device according to claim 2.
The predetermined condition is that any of the current target values for each of the three phases calculated by the filter operation unit, the average value, the effective value, and other statistical values, or all of them decrease by the second reference value or more. The voltage is restored,
The control device according to claim 2 or 3.
A control device for a self-excited converter connected to an alternating current system, the control device comprising:
Transmission of each order of the power system acquired by injecting harmonics of a predetermined order of the power system with respect to an analysis model of the power system created using an impedance model of a device connected to the power system A filter operation unit that calculates current target values for each of the three phases based on voltages for each of the three phases of the AC system so as to realize a function;
A coordinate conversion unit for converting the current target values for each of the three phases calculated by the filter operation unit into a first d-axis current target value and a first q-axis current target value;
A converter control unit that controls the self-excited converter based on the second d-axis current target value based on the required power and the first d-axis current target value and the first q-axis current target value converted by the coordinate conversion unit. When,
Control device comprising:
The control device of the self-excited converter connected to the AC system is
In order to realize a transfer function based on the RLC component of an AC filter capable of suppressing harmonics in a predetermined frequency band, current target values for each of the three phases are calculated based on voltages for each of the three phases of the AC system,
Converting the calculated current target values for each of the three phases into a first d-axis current target value and a first q-axis current target value;
Controlling the self-excited converter based on a second d-axis current target value based on a required power and the converted first d-axis current target value and first q-axis current target value;
Control method.
The control device of the self-excited converter connected to the AC system is
Transmission of each order of the power system acquired by injecting harmonics of a predetermined order of the power system with respect to an analysis model of the power system created using an impedance model of a device connected to the power system In order to realize the function, the current target value for each of the three phases is calculated based on the voltage for each of the three phases of the AC system,
Converting the calculated current target values for each of the three phases into a first d-axis current target value and a first q-axis current target value;
Controlling the self-excited converter based on a second d-axis current target value based on a required power and the converted first d-axis current target value and first q-axis current target value;
Control method.
In a computer that is a control device of a self-excited converter connected to an AC system,
In order to realize a transfer function based on an RLC component of an AC filter capable of suppressing harmonics in a predetermined frequency band, current target values for each of the three phases are calculated based on voltages for each of the three phases of the AC system,
Converting the calculated current target values for each of the three phases into a first d-axis current target value and a first q-axis current target value,
The self-excited converter is controlled based on a second d-axis current target value based on a required power and the converted first d-axis current target value and first q-axis current target value.
program.
In a computer that is a control device of a self-excited converter connected to an AC system,
Transmission of each order of the power system acquired by injecting harmonics of a predetermined order of the power system with respect to an analysis model of the power system created using an impedance model of a device connected to the power system In order to realize the function, the current target value for each of the three phases is calculated based on the voltage for each of the three phases of the AC system,
Converting the calculated current target values for each of the three phases into a first d-axis current target value and a first q-axis current target value,
The self-excited converter is controlled based on a second d-axis current target value based on a required power and the converted first d-axis current target value and first q-axis current target value.
program.