JP7087455B2 - Control device, static VAR compensator, and control method - Google Patents

Description

The present invention relates to a control device for static power control, a static power compensator, and a control method.

The reactive power compensator has a function of outputting reactive power or reactive current according to the measured value of the voltage of the power system (system voltage), and is widely applied in various fields such as electric power and electric railway. The static static compensator (Static Var Compensator, SVC), STATCOM (Static Synchronous Compensator), power conditioner (Power Conditioning System, PCS), storage battery system, synchronous generator and the like are included.

In the power system, it is desirable that the system voltage be maintained within a predetermined range. Further, in a power system in which a distributed power source such as photovoltaic power generation is introduced, it is desirable to suppress fluctuations in the system voltage. Therefore, a static power compensator is often installed for the purpose of maintaining the system voltage and suppressing voltage fluctuations.

However, when the state of the power system changes and the short-circuit capacity decreases due to the switching of the upper system or the distribution system due to the occurrence of an accident in the power system, maintenance, or the like, a hunting phenomenon may occur. Further, in a distribution system in which a large number of static VAR compensators are introduced, a hunting phenomenon may occur even when a plurality of static VAR compensators are connected to the same feeder by system switching.

The hunting phenomenon is a phenomenon in which the output of the static VAR compensator promotes voltage fluctuations and makes the system voltage unstable by increasing the gain of the entire control loop that combines the static VAR compensator and the power system. Point to.

As a technique for suppressing this hunting phenomenon, a control device for a static varsifying power compensator is known (see, for example, Patent Document 1). This static varsator compensator is provided in the AC system and at least performs varsator compensator and AC voltage control, and the control device includes a detection means, a determination means, and an adjustment means.

The detecting means detects the vibration component of the AC current of the static varsator power compensator, which occurs as the short-circuit capacity of the AC system becomes smaller. The determination means determines the continuation of vibration based on the vibration component of the detected alternating current. When the determining means determines that the vibration continues, the adjusting means adjusts the control parameters for controlling the static varsator power compensator in order to limit the vibration component. This makes it possible to suppress the hunting phenomenon that occurs as the short-circuit capacity of the AC system decreases.

Japanese Patent No. 36055516

However, in the technique of Patent Document 1, it is difficult to determine whether the detected vibration component of the alternating current is generated by the hunting phenomenon or by a factor other than the hunting phenomenon. Factors other than the hunting phenomenon include, for example, tap switching of an SVR (Step Voltage Regulator) installed in a distribution system, fluctuations in the output of photovoltaic power generation, and the like.

If the vibration continuation of the alternating current is allowed to identify that the vibration component is generated by the hunting phenomenon, the control parameter is adjusted after the vibration continuation is determined, so that the suppression of the hunting phenomenon may be delayed. ..

Further, in the technique of Patent Document 1, the control parameter is returned to the predetermined value after a predetermined time after the vibration is settled by adjusting the control parameter. Therefore, if the short-circuit capacitance of the AC system does not return to the normal state when the control parameter returns to the predetermined value, the hunting phenomenon will occur again even for a short time. Further, the same phenomenon is repeated every time the operation of returning the control parameter to the predetermined value is performed.

Further, in the technique of Patent Document 1, when the number of vibration reproductions exceeds a predetermined value, the means for returning to the predetermined value is locked. Therefore, even if the short-circuit capacity of the AC system returns to the normal state, the control parameters may not return to the prior values, and appropriate static vars compensation and AC voltage control may not be performed.

It should be noted that such a problem occurs not only when the hunting phenomenon occurs due to a decrease in the short-circuit capacity of the AC system but also when the voltage of the power system becomes unstable due to another factor.

In one aspect, the present invention aims to quickly stabilize the voltage of an unstable power system in a system in which reactive power control is performed on the power system.

According to one embodiment, the control device includes a control unit, a signal input unit, and an adjustment unit. The control unit uses the measured value of the voltage of the power system and the control gain to generate a first control signal for controlling the reactive power for the power system. The signal input unit inputs a signal that vibrates at a predetermined frequency to the control unit. At this time, the control unit generates the first control signal based on the addition result of adding the signal input by the signal input unit to the second control signal generated from the measured value of the voltage, and the adjusting unit generates the first control signal. 2 The control gain is adjusted based on the frequency component of the predetermined frequency included in the control signal.

According to one embodiment, in a system in which the reactive power control for the power system is performed, the voltage of the unstable power system can be quickly stabilized.

It is a block diagram of the reactive power control system. It is a 1st block diagram of a control device. It is a 1st block diagram of a control part. It is a block diagram of the adjustment part. It is a 2nd block diagram of a control device. It is the 2nd block diagram of the control part. It is a 3rd block diagram of the control part. It is a 4th block diagram of the control part. It is a 5th block diagram of the control part. It is a sixth block diagram of the control part. It is a flowchart of 1st control processing. It is a flowchart of the 2nd control process.

Hereinafter, embodiments will be described in detail with reference to the drawings.
FIG. 1 shows a configuration example of the reactive power control system of the embodiment. The reactive power control system of FIG. 1 includes an AC power system 101, a voltage measuring instrument 102, a transformer 103, and an reactive power compensator 104.

The static VAR compensator 104 is connected to the power system 101 via the voltage measuring instrument 102 and the transformer 103. The voltage measuring instrument 102 measures the system voltage of the power system 101 and outputs the measured value of the system voltage to the static power compensator 104. The reactive power compensator 104 outputs reactive power or reactive current to the power system 101 according to the effective value of the system voltage so that the system voltage becomes constant or the fluctuation of the system voltage is suppressed.

The static power compensator 104 includes a control device 111 and a static power control circuit 112. The reactive power control circuit 112 may be a self-excited converter or a separately-excited transducer. The control device 111 calculates the reactive power control signal CS from the measured value of the system voltage output by the voltage measuring instrument 102, and outputs the reactive power control signal CS to the reactive power control circuit 112. As the reactive power control signal CS, the command value Qref of the reactive power or the command value Iref of the reactive current can be used.

FIG. 2 shows a first configuration example of the control device 111 of FIG. The control device 111 of FIG. 2 includes a control unit 201, an adjustment unit 202, and a signal input unit 203. As the control unit 201, the adjustment unit 202, and the signal input unit 203, a DSP (Digital Signal Processor), a CPU (Central Processing Unit), a multi-core CPU, a programmable device, or the like can be used. The programmable device may be an FPGA (Field Programmable Gate Array) or a PLD (Programmable Logic Device).

The control unit 201 generates an ineffective power control signal CS by using the measured value Vm of the system voltage and the gain signal G indicating the control gain.

The signal input unit 203 inputs a signal HN that vibrates at a predetermined frequency to the control unit 201. Then, the control unit 201 generates a control signal CSB from the measured value Vm, and generates an invalid power control signal CS based on the addition result of adding the signal HN to the control signal CSB. For example, the predetermined frequency may be the frequency of vibration in the hunting phenomenon (hunting frequency), and the signal HN may be a sine wave vibrating at the hunting frequency.

The adjusting unit 202 adjusts the control gain based on the frequency component of the predetermined frequency included in the control signal CSB generated by the control unit 201, and outputs the gain signal G to the control unit 201.

FIG. 3 shows a first configuration example of the control unit 201 of FIG. The control unit 201 of FIG. 3 includes a calculation unit 301, a voltage control unit 302, a multiplication unit 303, and an addition unit 304. The voltage control unit 302 includes a subtraction unit 311, a proportional unit 312, an integration unit 313, a differentiation unit 314, and an addition unit 315, and performs PID (Proportional-Integral-Differential) control.

The calculation unit 301 calculates the effective value Vms of the system voltage from the measured value Vm of the system voltage, and outputs the calculated effective value Vms of the system voltage to the voltage control unit 302. The calculation unit 301 may output the d-axis voltage synchronized with the system voltage to the voltage control unit 302 instead of the effective value Vms of the system voltage.

The voltage control unit 302 generates a signal that is the basis of the reactive power control signal CS from the effective value Vms of the system voltage. The subtraction unit 311 is a difference (deviation) between the voltage command value Vref and the effective value Vms.
Is calculated, and the calculated deviation is output to the proportional unit 312, the integrating unit 313, and the differential unit 314. The proportional unit 312 outputs a value proportional to the deviation, the integrating unit 313 outputs the integrated value of the deviation, and the differential unit 314 outputs the differential value of the deviation. The addition unit 315 outputs the sum of the output values of the proportional unit 312, the integration unit 313, and the differentiation unit 314 to the multiplication unit 303.

The multiplication unit 303 multiplies the output of the addition unit 315 by the control gain indicated by the gain signal G to generate a control signal CSB, and outputs the control signal CSB to the addition unit 304 and the adjustment unit 202. The addition unit 304 adds the signal HN output by the signal input unit 203 to the control signal CSB to generate an ineffective power control signal CS, and outputs the generated ineffective power control signal CS.

As the signal HN, for example, a sine wave that vibrates at a hunting frequency can be used. The hunting frequency is the frequency of vibration that appears in the measured value Vm and the effective value Vms when the control gain indicated by the gain signal G is increased. The hunting frequency can be obtained, for example, by the following method.

(1) In the reactive power control system, the control gain is experimentally increased and the frequency of vibration appearing in the effective value Vms is measured.
(2) Using simulation software or the like that simulates the operation of the disabled power control system, the control gain is increased and the frequency of vibration appearing in the effective value Vms is measured.
(3) The stability of the reactive power control system is analyzed by numerical analysis software or the like, and the angular frequency (phase crossing angle frequency) at the point where the phase of the reactive power control system becomes −180 ° is obtained.

FIG. 4 shows a configuration example of the adjustment unit 202 of FIG. The adjusting unit 202 of FIG. 4 includes an extraction unit 401, a subtraction unit 402, a dead zone control unit 403, a switching unit 404, and a gain signal generation unit 405.

The extraction unit 401 extracts a frequency component having the same frequency as the signal HN from the control signal CSB, and outputs a signal indicating the magnitude of the extracted frequency component. The magnitude of the frequency component may be the absolute value of the frequency component. For example, the extraction unit 401 can determine the magnitude of the frequency component by using FFT (Fast Fourier Transform), DFT (Discrete Fourier Transform), or the like. Further, the extraction unit 401 can also obtain the magnitude of the frequency component by combining an average process such as a bandpass filter, an absolute value process, a low pass filter, and a moving average.

The subtraction unit 402 subtracts the magnitude of the frequency component indicated by the signal output by the extraction unit 401 from the threshold value T to obtain the difference (deviation) between the threshold value T and the magnitude of the frequency component, and the deviation signal indicating the obtained deviation. Is output to the dead zone control unit 403. The dead zone control unit 403 sets a dead zone in a predetermined range with respect to the deviation, and when the deviation is outside the range of the dead zone, outputs the deviation signal to the switching unit 404.

The switching unit 404 performs on / off control for the switch 411 according to the control signal SW, and when the control signal SW indicates ON, the switching unit 404 outputs the deviation signal output by the dead zone control unit 403 to the gain signal generation unit 405. On the other hand, when the control signal SW indicates off, the switching unit 404 outputs a deviation signal indicating deviation 0 to the gain signal generation unit 405.

The gain signal generation unit 405 includes, for example, an integrator, and when the deviation indicated by the deviation signal is a negative value, the control gain is decreased, and when the deviation is a positive value, the control gain is increased and the deviation is increased. If it is 0, the control gain is not changed. As a result, when the magnitude of the frequency component is larger than the threshold value T, the control gain is reduced, and when the magnitude of the frequency component is smaller than the threshold value T, the control gain is reduced.
Control gain increases. Then, the gain signal generation unit 405 outputs a gain signal G indicating the control gain.

For example, the control gain can be adjusted between 0 and 1. In this case, the gain signal generation unit 405 sets the minimum value of the control gain to a value of 0 or more and less than 1, sets the maximum value of the control gain to 1, and sets the control gain in the range from the minimum value to the maximum value. Increase or decrease.

It is desirable that the threshold value T for the magnitude of the frequency component of the hunting frequency is smaller than the effective value of the signal HN output by the signal input unit 203. If the magnitude of the frequency component is smaller than the magnitude of the signal HN, the gain of the round-trip transfer function of the reactive power control system becomes 1 or less at the hunting frequency, and a gain margin can be secured. For example, the threshold value T may be about 0.5 times the effective value of the signal HN.

According to the configuration of the control device 111 shown in FIGS. 2 to 4, the control gain is quickly adjusted in response to only the frequency component peculiar to the hunting phenomenon included in the measured value Vm of the system voltage. Therefore, the control gain is not erroneously adjusted for vibrations generated by factors other than the hunting phenomenon, such as tap changeover of SVR installed in the distribution system and output fluctuation of photovoltaic power generation.

Further, even when the state of the power system changes again and returns to the original state, the control gain is adjusted to the optimum value according to the system conditions at that time, and the appropriate reactive power or reactive current is adjusted from the reactive power control circuit 112. Can be output. In this way, since the control gain is always adjusted to the optimum value, the occurrence of the hunting phenomenon itself is avoided, and the suppression of the hunting phenomenon is not delayed.

By the way, it is conceivable that the control gain increases or decreases due to the magnitude of the frequency component of the hunting frequency increasing or decreasing in the vicinity of the threshold value T, and the control becomes unstable. Even in such a case, by providing the dead zone control unit 403, it is possible to suppress an increase / decrease in the control gain and avoid destabilization of the control.

Further, by providing the switching unit 404, it is possible to suppress the deviation signal generated by the subtraction unit 402 from being constantly input to the gain signal generation unit 405, and to limit the adjustment of the control gain to only a desired period. It will be possible. As the on / off control by the switching unit 404, for example, the following method can be considered.
(A) Whether or not the on / off control switching unit 404 having a predetermined cycle inputs the deviation signal generated by the subtraction unit 402 to the gain signal generation unit 405, that is, whether the control signal SW is turned on or off. Is switched at a predetermined cycle.

In this case, the signal input unit 203 outputs the signal HN to the addition unit 304 during the period when the control signal SW is on, and stops the output of the signal HN during the period when the control signal SW is off. .. As a result, the signal HN is input to the addition unit 304 during the period when the deviation signal is input to the gain signal generation unit 405, and the signal HN is input during the period when the deviation signal is not input to the gain signal generation unit 405. It will be stopped.
(B) On / off control based on the detection result of the hunting phenomenon When the hunting phenomenon is detected, the control signal SW is turned on and the deviation signal generated by the subtraction unit 402 is transmitted to the gain signal generation unit 405. After inputting, when the control gain returns to the maximum value, the control signal SW is turned off and the input of the deviation signal is stopped.

When the hunting phenomenon is detected, the signal input unit 203 outputs the signal HN to the addition unit 304, and then stops the output of the signal HN when the control gain returns to the maximum value. As a result, the signal HN is input to the addition unit 304 during the period when the deviation signal is input to the gain signal generation unit 405, and the signal HN is input during the period when the deviation signal is not input to the gain signal generation unit 405. It will be stopped.

For example, when the system is switched due to an accident, maintenance, etc. and a hunting phenomenon occurs, the control gain is less than 1 in order to suppress the hunting phenomenon by turning on the control signal SW. Adjusted to value. After that, when the system is switched to the original state due to the recovery of the accident, the end of maintenance, etc., the hunting phenomenon subsides and the control gain returns to the maximum value 1. Therefore, by turning off the control signal SW, it is possible to avoid unnecessary adjustment of the control gain.
(C) Combination of (a) and (b) The switching unit 404 and the signal input unit 203 apply the on / off control of a predetermined cycle and the on / off control based on the detection result of the hunting phenomenon in combination. You can also.

FIG. 5 shows a second configuration example of the control device 111 that performs on / off control based on the detection result of the hunting phenomenon. The control device 111 of FIG. 5 has a configuration in which a detection unit 501 is added to the control device 111 of FIG.

The detection unit 501 monitors the measured value Vm of the system voltage and detects an unstable state in which the measured value Vm is not stable as a hunting phenomenon. For example, the detection unit 501 can detect an unstable state by using the method of Patent Document 1 and the like. Then, when the detection unit 501 detects the hunting phenomenon, the detection unit 501 outputs a signal indicating the occurrence of the hunting phenomenon to the adjustment unit 202 and the signal input unit 203.

In the control unit 201 of FIG. 3, there is a degree of freedom in the position of the multiplication unit 303, the position of the addition unit 304, and the extraction position of the control signal CSB, and these positions can be changed. For example, the position of the multiplication unit 303 may be in the front stage or the rear stage of the addition unit 304. However, the extraction position of the control signal CSB is limited to the stage before the addition unit 304, and it is desirable that the position is immediately before the addition unit 304.

FIG. 6 shows a second configuration example of the control unit 201 of FIG. The control unit 201 of FIG. 6 has a configuration in which the positions of the multiplication unit 303 and the addition unit 304 are changed in the control unit 201 of FIG. In this case, the multiplication unit 303 and the addition unit 304 are arranged between the subtraction unit 311 and the proportional unit 312, the integration unit 313, and the differentiation unit 314.

The subtraction unit 311 outputs the deviation between the voltage command value Vref and the effective value Vms to the multiplication unit 303, and the multiplication unit 303 multiplies the deviation by the control gain to generate the control signal CSB. The addition unit 304 adds the signal HN to the control signal CSB and outputs the addition result to the proportional unit 312, the integration unit 313, and the differentiation unit 314. The addition unit 315 outputs the sum of the output values of the proportional unit 312, the integration unit 313, and the differentiation unit 314 as the reactive power control signal CS.

FIG. 7 shows a third configuration example of the control unit 201 of FIG. The control unit 201 of FIG. 7 has a configuration in which the position of the multiplication unit 303 is changed in the control unit 201 of FIG. In this case, the multiplying unit 303 is arranged between the subtracting unit 311 and the proportional unit 312, the integrating unit 313, and the differential unit 314.

The subtraction unit 311 outputs the deviation between the voltage command value Vref and the effective value Vms to the multiplication unit 303, and the multiplication unit 303 multiplies the deviation by the control gain and obtains the multiplication result in the proportional unit 312, the integration unit 313, and the integration unit 303. Output to the differential unit 314. The addition unit 315 generates a control signal CSB indicating the sum of the output values of the proportional unit 312, the integration unit 313, and the differentiation unit 314.

In the control unit 201 of FIG. 3, it is also possible to integrate the function of the proportional unit 312 and the function of the multiplication unit 303.

FIG. 8 shows a fourth configuration example of the control unit 201 in which the voltage control is changed from the PID control to the proportional control. The control unit 201 of FIG. 8 has a configuration in which the voltage control unit 302 is replaced with the voltage control unit 801 and the multiplication unit 303 is replaced with the multiplication unit 802 in the control unit 201 of FIG.

The voltage control unit 801 includes the subtraction unit 311, and the subtraction unit 311 outputs the deviation between the voltage command value Vref and the effective value Vms to the multiplication unit 802. The multiplication unit 802 has both the function of the proportional unit 312 and the function of the multiplication unit 303, and multiplies the deviation by the control gain to generate a control signal CSB indicating the multiplication result.

In this case, the control gain indicated by the gain signal G is adjusted from 0 to the proportional gain of the proportional unit 312. Therefore, the gain signal generation unit 405 of the adjustment unit 202 sets the minimum value of the control gain to a value of 0 or more and less than the proportional gain, sets the maximum value of the control gain to the value of the proportional gain, and sets the minimum value to the maximum value. Increase or decrease the control gain in the range up to.

FIG. 9 shows a fifth configuration example of the control unit 201 in which the voltage control is changed from the PID control to the proportional integral control. In the control unit 201 of FIG. 3, the control unit 201 of FIG. 9 replaces the voltage control unit 302 with the voltage control unit 901, replaces the multiplication unit 303 with the multiplication unit 802, and changes the positions of the multiplication unit 802 and the addition unit 304. Has the same configuration.

The voltage control unit 901 includes a subtraction unit 311, an integration unit 313, and an addition unit 315, and the subtraction unit 311 outputs the deviation between the voltage command value Vref and the effective value Vms to the multiplication unit 802. The multiplication unit 802 multiplies the deviation by the control gain to generate a control signal CSB indicating the multiplication result. Also in this case, the control gain indicated by the gain signal G is adjusted from 0 to the proportional gain.

The addition unit 304 adds the signal HN to the control signal CSB and outputs the addition result to the integration unit 313 and the addition unit 315. The addition unit 315 outputs the sum of the output values of the addition unit 304 and the integration unit 313 as the reactive power control signal CS.

FIG. 10 shows a sixth configuration example of the control unit 201 in which the voltage control is changed to the voltage fluctuation suppression control by a filter. The control unit 201 of FIG. 10 has a configuration in which the voltage control unit 302 is replaced with the voltage control unit 1001 in the control unit 201 of FIG.

The voltage control unit 1001 includes a high-pass filter 1011 and the high-pass filter 1011 outputs a frequency component having a frequency higher than the cutoff frequency among the frequency components having a fluctuating effective value Vms to the multiplication unit 303. The multiplication unit 303 multiplies the output of the high-pass filter 1011 by the control gain to generate a control signal CSB indicating the multiplication result.

FIG. 11 shows an example of the first control process in which the multiplication unit 303 or the multiplication unit 802 is performed by the control unit 201 arranged in front of the addition unit 304, as shown in FIGS. 3 and 6 to 10. It is a flowchart which shows.

First, the control unit 201 generates a control signal CSB using the measured value Vm of the system voltage and the control gain (step 1101), and the adjustment unit 202 is based on the frequency component of the hunting frequency included in the control signal CSB. To adjust the control gain (step 1102). next,
The control unit 201 generates an invalid power control signal CS based on the addition result of adding the signal HN to the control signal CSB (step 1103).

FIG. 12 is a flowchart showing an example of a second control process in which the multiplication unit 303 or the multiplication unit 802 is performed by the control unit 201 arranged in the subsequent stage of the addition unit 304.

First, the control unit 201 generates a control signal CSB using the measured value Vm of the system voltage (step 1201), and the adjustment unit 202 generates a control gain based on the frequency component of the hunting frequency included in the control signal CSB. Is adjusted (step 1202).

Next, the control unit 201 generates an invalid power control signal CS using the addition result of adding the signal HN to the control signal CSB and the control gain (step 1203). For example, the control unit 201 outputs a multiplication result obtained by multiplying the addition result by the control gain as an invalid power control signal CS.

The configuration of the reactive power control system of FIG. 1 is only an example, and some components may be omitted or changed depending on the use or conditions of the reactive power control system.

The configuration of the control device 111 of FIGS. 2 and 5 is only an example, and some components may be omitted or changed depending on the use or conditions of the reactive power control system.

The configuration of the control unit 201 of FIGS. 3 and 6 to 10 is only an example, and some components may be omitted or changed depending on the use or conditions of the reactive power control system. For example, the multiplication unit 303 or the multiplication unit 802 may be arranged after the addition unit 304.

The configuration of the adjusting unit 202 in FIG. 4 is only an example, and some components may be omitted or changed depending on the application or conditions of the reactive power control system. For example, if the control is unlikely to become unstable, the dead zone control unit 403 can be omitted. Further, if the deviation signal generated by the subtraction unit 402 may be constantly input to the gain signal generation unit 405, the switching unit 404 can be omitted.

The flowcharts of FIGS. 11 and 12 are merely examples, and some processes may be omitted or changed depending on the configuration or conditions of the reactive power control system.

Although the embodiments of the disclosure and their advantages have been described in detail, those skilled in the art will be able to make various changes, additions and omissions without departing from the scope of the invention expressly described in the claims. Let's do it.

101 Power system 102 Voltage measuring instrument 103 Transformer 104 Invalid power compensator 111 Control device 112 Invalid power control circuit 201 Control unit 202 Coordinating unit 203 Signal input unit 301 Calculation unit 302, 801, 901, 1001 Voltage control unit 303, 802 Multiplying Part 304, 315 Addition part 311, 402 Subtraction part 312 Proportion part 313 Integration part 314 Differentiation part 401 Extraction part 403 Insensitive band control part 404 Switching part 405 Gain signal generation part 411 Switch 501 Detection part 1011 High pass filter

Claims (11)

A control unit that generates a first control signal for reactive power control for the power system using the measured value of the voltage of the power system and the control gain.
A signal input unit that inputs a signal that vibrates at a predetermined frequency to the control unit,
It is equipped with an adjustment unit that adjusts the control gain.
The control unit generates the first control signal based on the addition result of adding the signal vibrating at the predetermined frequency to the second control signal generated from the measured value, and the adjusting unit generates the first control signal. A control device comprising adjusting the control gain based on a frequency component having the same frequency as the predetermined frequency included in the control signal. The control device according to claim 1, wherein the predetermined frequency is a frequency of vibration that appears in the measured value when the control gain is increased. The control device according to claim 1 or 2, wherein the control unit includes an addition unit that adds a signal vibrating at the predetermined frequency to the second control signal to generate the addition result. The adjusting unit is characterized in that when the magnitude of the frequency component is larger than the threshold value, the control gain is decreased, and when the magnitude of the frequency component is smaller than the threshold value, the control gain is increased. The control device according to any one of claims 1 to 3. The adjustment unit
An extraction unit that extracts the frequency component from the second control signal and outputs a first signal indicating the magnitude of the frequency component.
Using the first signal, a subtraction unit that obtains a difference between the magnitude of the frequency component and the threshold value and outputs a second signal indicating the difference, and a subtraction unit.
A gain signal generation unit that generates a gain signal indicating the control gain using the second signal and outputs the gain signal, and a gain signal generation unit.
4. The control device according to claim 4. The control device according to claim 5, wherein the adjusting unit further includes a switching unit that switches whether or not to input the second signal to the gain signal generation unit. The switching unit switches whether or not to input the second signal to the gain signal generation unit at a predetermined cycle.
The signal input unit inputs a signal that vibrates at the predetermined frequency to the control unit while the second signal is input to the gain signal generation unit, and the second signal is input to the gain signal generation unit. The control device according to claim 6, wherein the input of a signal vibrating at the predetermined frequency is stopped during a period during which the signal is not input. The control device further includes a detection unit that detects an unstable state in which the measured value is not stable.
When the detection unit detects the unstable state, the switching unit inputs the second signal to the gain signal generation unit, inputs the second signal, and then obtains the control gain indicated by the gain signal. When it returns to the maximum value, the input of the second signal is stopped and the input is stopped.
When the detection unit detects the unstable state, the signal input unit inputs a signal vibrating at the predetermined frequency to the control unit, inputs a signal vibrating at the predetermined frequency, and then the gain signal is generated. The control device according to claim 6, wherein when the indicated control gain returns to the maximum value, the input of the signal vibrating at the predetermined frequency is stopped. A reactive power control circuit that controls the reactive power of the power system based on the first control signal,
A control unit that generates the first control signal using the measured value of the voltage of the power system and the control gain.
It is provided with an adjusting unit for adjusting the control gain based on the frequency component of a predetermined frequency included in the second control signal generated from the measured value.
The control unit is an ineffective power compensation device, characterized in that the first control signal is generated based on the addition result of adding a signal vibrating at the same frequency as the predetermined frequency to the second control signal. A control signal is generated using the measured value of the voltage of the power system and the control gain.
The control gain is adjusted based on the frequency component of the predetermined frequency included in the control signal.
Based on the addition result of adding a signal vibrating at the same frequency as the predetermined frequency to the control signal, an invalid power control signal for controlling the reactive power for the power system is generated.
A control method characterized by that. Generate a control signal using the measured value of the voltage of the power system,
The control gain is adjusted based on the frequency component of the predetermined frequency included in the control signal.
Using the addition result of adding a signal vibrating at the same frequency as the predetermined frequency to the control signal and the control gain, an invalid power control signal for controlling the reactive power for the power system is generated.
A control method characterized by that.

Images