JP6811145B2 - Voltage regulator and voltage regulator - Google Patents

Description

The present invention relates to a voltage adjusting device and a voltage adjusting system for adjusting a voltage change occurring in a power transmission line of a power system.

In recent years, distributed power sources using natural energy, which have been actively introduced, generate irregularly the amount of power generated depending on the season, weather, region, etc., so the system voltage of the power system connected to the distributed power sources is Fluctuations tend to be relatively large. In order to properly control the system voltage of such a power system, tap switching type such as SVR (Step Voltage Regulator) and LRT (Load Ratio control Transformer) is applied to power transmission lines such as transmission lines, distribution lines, and drop lines. A voltage regulator is provided.

These voltage regulators adjust the transformation ratio by switching the taps of the tapped transformer that transforms the AC voltage from the power system and applies it to the power transmission line, thereby adjusting the voltage on the secondary side (of the voltage regulator). The output voltage) is controlled so as to fall within a predetermined range including an appropriate voltage value (reference voltage). In this case, a time determination method (see Patent Document 1) or an integration determination method (see Patent Document 2) is used as a method for determining the necessity of tap switching.

In the time determination method, the time when the voltage of the power transmission line deviates from the preset dead zone region is measured, and when the measurement result exceeds a predetermined time, the taps are switched so that the voltage becomes an appropriate voltage. In the integration judgment method, the deviation amount (difference voltage between the voltage of the power transmission line and the dead zone region) when the voltage of the power transmission line deviates from the preset dead zone region is integrated, and the integration result exceeds a predetermined range. At that time, switch the tap so that the voltage becomes appropriate.

Among the voltage regulators, there are SSR (Step Switched Reactor) and ShR (Shunt Reactor) that reduce the voltage of the increased power transmission line by connecting the reactor in parallel to the power transmission line via a switch. .. Further, there is an SSC (Step Switched Capacitor) that raises the voltage of the lowered power transmission line by connecting a capacitor in parallel to the power transmission line via a switch (see Patent Document 3). The above-mentioned time determination method and integration determination method are also used when the switch is switched by SSR, ShR, and SSC.

Japanese Unexamined Patent Publication No. 2011-217581 Japanese Unexamined Patent Publication No. 11-24763 Japanese Unexamined Patent Publication No. 2012-228405

However, when the time determination method is used in the above-mentioned voltage adjusting device, there is a delay before the control for switching the tap or the switch is performed, and the tap or the switch is switched in response to the voltage fluctuation in which the voltage suddenly fluctuates. Sometimes not. Further, for a voltage fluctuation having a period longer than the operation time period, the direction of control and the direction of fluctuation are opposite to each other, and frequent switching or unnecessary switching may occur. On the other hand, when the integration judgment method is used, the taps can be switched so that the voltage becomes appropriate even when a steep voltage fluctuation occurs, but the tap or switch is switched every time the voltage fluctuates. There is a possibility that you may tap or switch unnecessarily.

The present invention has been made in view of such circumstances, and an object of the present invention is a voltage regulator and a voltage capable of appropriately adjusting the voltage of a power transmission line while suppressing unnecessary switch switching. To provide a coordination system.

The voltage adjusting device according to the present invention is a voltage adjusting device that adjusts the voltage of the power transmission line by controlling switching of a switch that connects a reactor or a capacitor in parallel to the power transmission line, and is the power transmission. A detection unit that detects the voltage of the line, an A / D conversion unit that digitizes the voltage detected by the detection unit, and an A / D conversion unit that calculates the effective value of the digitized voltage to generate an effective value signal. An effective value calculation unit to be output, a digital filter that removes a steep voltage fluctuation component from the effective value signal output by the effective value calculation unit and outputs an operation judgment voltage signal, and an operation judgment voltage signal output by the digital filter. Based on the above, a determination unit that determines whether or not the switch needs to be switched, and when the determination unit determines that switching is necessary, the switch so that the voltage of the power transmission line approaches the reference voltage. The digital filter is provided with a switching command unit that outputs a switching command , filters the effective value signal output by the effective value calculation unit during a predetermined period, and outputs the effective value signal to Vs. The operation is performed by performing the operation shown in the following equation (1), where Ts is the sampling period, Tperiod is the predetermined period, Nperiod is the number of effective value signals during the predetermined period, and Z is the Z conversion operator. it calculates and outputs determination voltage signal VTp.

In the present invention, the voltage of the power transmission line is sampled and A / D converted, and the effective value signal of the converted voltage is filtered by a digital filter to generate an operation judgment voltage signal, and the generated operation judgment voltage signal is generated. When it is determined that the switch for connecting the reactor or the capacitor in parallel to the power transmission line needs to be switched, the switch switching command is output. As a result, the necessity of switching is determined based on the operation determination voltage signal obtained by removing the steep voltage fluctuation component from the effective value signal, so that unnecessary switching of the switch is suppressed.
Further, in the present invention, since the effective value signal during the predetermined period is filtered, more voltage fluctuation components are removed as the predetermined period is longer, and unnecessary switching of the switch is reduced. Further, the operation determination voltage signal is calculated by the filtering process represented by the equation (1). As a result, the necessity of switching is determined based on the operation determination voltage signal obtained by removing the steep voltage fluctuation component from the effective value signal, so that unnecessary switching of the switch is preferably suppressed.

In the voltage adjusting device according to the present invention, the determination unit determines that the switch needs to be switched when the operation determination voltage signal deviates from a preset dead zone region.

In the present invention, when the operation determination voltage signal deviates from the dead zone region, the switching command is output in a quick response, so that the voltage of the power transmission line is suppressed from deviating from the appropriate range.

The voltage adjusting device according to the present invention is a voltage adjusting device that adjusts the voltage of the power transmission line by controlling switching of a switch for connecting a reactor or a capacitor in parallel to the power transmission line. A detection unit that detects the line voltage, an A / D conversion unit that digitizes the voltage detected by the detection unit, and an A / D conversion unit that calculates the effective value of the digitized voltage to generate an effective value signal. An effective value calculation unit to be output, a digital filter that removes a steep voltage fluctuation component from the effective value signal output by the effective value calculation unit and outputs an operation judgment voltage signal, and an operation judgment voltage signal output by the digital filter. Based on the above, a determination unit that determines whether or not the switch needs to be switched, and when the determination unit determines that switching is necessary, the switch so that the voltage of the power transmission line approaches the reference voltage. The digital filter is provided with a switching command unit that outputs a switching command, filters the effective value signal output by the effective value calculation unit during a predetermined period, and outputs the effective value signal to Vs. , Z conversion operator is Z, predetermined filter order is M, N, predetermined coefficient is ai (i = 0,1, ..., M), bj (j = 0,1, ... N). The operation determination voltage signal VTp is calculated and output by performing the calculation shown in the following equation (2), and the digital filter has a low pass for the predetermined filter orders M and N and the predetermined coefficients ai and bj. Set to function as a filter or bandpass filter.

In the present invention, the voltage of the power transmission line is sampled and A / D converted, and the effective value signal of the converted voltage is filtered by a digital filter to generate an operation judgment voltage signal, and the generated operation judgment voltage signal is generated. When it is determined that the switch for connecting the reactor or the capacitor in parallel to the power transmission line needs to be switched, the switch switching command is output. As a result, the necessity of switching is determined based on the operation determination voltage signal obtained by removing the steep voltage fluctuation component from the effective value signal, so that unnecessary switching of the switch is suppressed.
Further, in the present invention, since the effective value signal during the predetermined period is filtered, more voltage fluctuation components are removed as the predetermined period is longer, and unnecessary switching of the switch is reduced. Further, the operation determination voltage signal is calculated by a filtering process using a low-pass filter or a band-pass filter represented by the equation (2). As a result, from the effective value signal, a steep voltage fluctuation component within a time corresponding to the filter order and the filter coefficient can be removed, or only a voltage fluctuation component with a time corresponding to the filter order and the filter coefficient can be passed. Can be done.

The voltage adjusting device according to the present invention is a voltage adjusting device that adjusts the voltage of the power transmission line by controlling switching of a switch for connecting a reactor or a capacitor in parallel to the power transmission line. A detection unit that detects the line voltage, an A / D conversion unit that digitizes the voltage detected by the detection unit, and an A / D conversion unit that calculates the effective value of the digitized voltage to generate an effective value signal. An effective value calculation unit to be output, a digital filter that removes a steep voltage fluctuation component from the effective value signal output by the effective value calculation unit and outputs an operation judgment voltage signal, and an operation judgment voltage signal output by the digital filter. Based on the above, a determination unit that determines whether or not the switch needs to be switched, and when the determination unit determines that switching is necessary, the switch so that the voltage of the power transmission line approaches the reference voltage. The digital filter is provided with a switching command unit that outputs a switching command, filters the effective value signal output by the effective value calculation unit during a predetermined period, and outputs the effective value signal to Vs. , The Z conversion operator is Z, the predetermined filter order is M, the predetermined coefficient is hi (i = 0,1, ..., M), and the operation shown in the following equation (3) is performed. The determination voltage signal VTp is calculated and output, and the predetermined filter order M and the predetermined coefficient hi are set so that the digital filter functions as a low-pass filter or a band-pass filter.

In the present invention, the voltage of the power transmission line is sampled and A / D converted, and the effective value signal of the converted voltage is filtered by a digital filter to generate an operation judgment voltage signal, and the generated operation judgment voltage signal is generated. When it is determined that the switch for connecting the reactor or the capacitor in parallel to the power transmission line needs to be switched, the switch switching command is output. As a result, the necessity of switching is determined based on the operation determination voltage signal obtained by removing the steep voltage fluctuation component from the effective value signal, so that unnecessary switching of the switch is suppressed.
Further, in the present invention, since the effective value signal during the predetermined period is filtered, more voltage fluctuation components are removed as the predetermined period is longer, and unnecessary switching of the switch is reduced. Further, the operation determination voltage signal is calculated by a filtering process using a low-pass filter or a band-pass filter represented by the equation (3). As a result, from the effective value signal, a steep voltage fluctuation component within a time corresponding to the filter order and the filter coefficient can be removed, or only a voltage fluctuation component with a time corresponding to the filter order and the filter coefficient can be passed. Can be done.

The voltage adjusting device according to the present invention is a voltage adjusting device that adjusts the voltage of the power transmission line by controlling switching of a switch that connects a reactor or a capacitor in parallel to the power transmission line, and is the power transmission. A detection unit that detects the voltage of the line, an A / D conversion unit that digitizes the voltage detected by the detection unit, and an A / D conversion unit that calculates the effective value of the digitized voltage to generate an effective value signal. An effective value calculation unit to be output, a digital filter that removes a steep voltage fluctuation component from the effective value signal output by the effective value calculation unit and outputs an operation judgment voltage signal, and an operation judgment voltage signal output by the digital filter. Based on the above, a determination unit that determines whether or not the switch needs to be switched, and when the determination unit determines that switching is necessary, the switch so that the voltage of the power transmission line approaches the reference voltage. The digital filter is provided with a switching command unit that outputs a switching command, filters the effective value signal output by the effective value calculation unit during a predetermined period, and the effective value calculation unit performs the filtering process. A second digital filter that outputs a second operation determination voltage signal by performing filtering processing on the effective value signal output during the second period shorter than the above period, and the second operation determination voltage signal. A second determination unit for determining whether or not the switch needs to be switched is further provided based on the above, and when the second determination unit determines that switching is necessary, the changeover command unit is described. A changeover command is further output to the switch so that the voltage of the power transmission line approaches the reference voltage.

In the present invention, the voltage of the power transmission line is sampled and A / D converted, and the effective value signal of the converted voltage is filtered by a digital filter to generate an operation judgment voltage signal, and the generated operation judgment voltage signal is generated. When it is determined that the switch for connecting the reactor or the capacitor in parallel to the power transmission line needs to be switched, the switch switching command is output. As a result, the necessity of switching is determined based on the operation determination voltage signal obtained by removing the steep voltage fluctuation component from the effective value signal, so that unnecessary switching of the switch is suppressed.
Further, in the present invention, since the effective value signal during the predetermined period is filtered, more voltage fluctuation components are removed as the predetermined period is longer, and unnecessary switching of the switch is reduced. Further, when it is determined that the switch needs to be switched based on the second operation determination voltage signal output by filtering the effective value signal during the second period shorter than the predetermined period, the switch change command is further issued. Output. As a result, even if it is determined that the switch does not need to be switched based on the operation determination voltage signal output during the predetermined period, the switch can be switched in response to a sudden voltage fluctuation during the second period. Will be done.

In the voltage adjusting device according to the present invention, the second determination unit needs to switch the switch when the second operation determination voltage signal deviates from the preset second dead zone region. judge.

In the present invention, when the second operation determination voltage signal deviates from the second dead zone region, a switching command is output in a quick response, so that the voltage of the power transmission line deviates from the appropriate range. It is suppressed.

In the voltage adjusting device according to the present invention, the second digital filter sets the effective value signal to Vs.
The sampling period Ts, the second Tbase period, a Z conversion operator as Z, by performing the calculation shown in the following equation (4), calculates and outputs the second operation determination voltage signal VTb To do.

In the present invention, the second operation determination voltage signal is calculated by the filtering process represented by the equation (4). As a result, the necessity of switching is determined based on the second operation determination voltage signal obtained by removing the steep voltage fluctuation component from the effective value signal, so that unnecessary switching of the switch is preferably suppressed.

In the voltage regulator according to the present invention, in the second digital filter, the effective value signal is Vs, the Z conversion operator is Z, the predetermined filter order is P, Q, and the predetermined coefficient is kk (k = 0, The second operation determination voltage signal VTb is calculated by setting 1, ..., P) and dl (l = 0,1, ... Q) and performing the calculation shown in the following equation (5). The output, the predetermined filter orders P and Q and the predetermined coefficients kk and dl are set so that the digital filter functions as a low-pass filter or a band-pass filter.

In the present invention, the second operation determination voltage signal is calculated by a filtering process using a low-pass filter or a band-pass filter represented by the equation (5). As a result, from the effective value signal, a steep voltage fluctuation component within a time corresponding to the filter order and the filter coefficient can be removed, or only a voltage fluctuation component with a time corresponding to the filter order and the filter coefficient can be passed. Can be done.

In the voltage adjusting device according to the present invention, in the second digital filter, the effective value signal is Vs, the Z conversion operator is Z, the predetermined filter order is P, and the predetermined coefficient is fk (k = 0,1,1). ..., P), and by performing the calculation shown in the following equation (6), the second operation determination voltage signal VTb is calculated and output, and the predetermined filter order P and the predetermined coefficient fk are obtained. , The digital filter is set to function as a low-pass filter or a band-pass filter.

In the present invention, the second operation determination voltage signal is calculated by a filtering process using a low-pass filter or a band-pass filter represented by the equation (6). As a result, from the effective value signal, a steep voltage fluctuation component within a time corresponding to the filter order and the filter coefficient can be removed, or only a voltage fluctuation component with a time corresponding to the filter order and the filter coefficient can be passed. Can be done.

The voltage adjusting device according to the present invention is a voltage adjusting device that adjusts the voltage of the power transmission line by controlling switching of a switch that connects a reactor or a capacitor in parallel to the power transmission line, and is the power transmission. A detection unit that detects the voltage of the line, an A / D conversion unit that digitizes the voltage detected by the detection unit, and an A / D conversion unit that calculates the effective value of the digitized voltage to generate an effective value signal. An effective value calculation unit to be output, a plurality of digital filters that remove a steep voltage fluctuation component from the effective value signal output by the effective value calculation unit to output an operation judgment voltage signal, and each of the plurality of digital filters output. Based on the operation determination voltage signal, the determination unit that separately determines whether or not the switch needs to be switched, and when the determination unit determines that switching is necessary, the voltage of the power transmission line is used as the reference voltage. The switch is provided with a switching command unit that outputs a switching command so as to approach the switch, and the plurality of digital filters perform filtering processing on effective value signals output by the effective value calculation unit during a predetermined period different from each other. To do .

In the present invention, the voltage of the power transmission line is sampled and A / D converted, and the effective value signal of the converted voltage is filtered by a digital filter to generate an operation judgment voltage signal, and the generated operation judgment voltage signal is generated. When it is determined that the switch for connecting the reactor or the capacitor in parallel to the power transmission line needs to be switched, the switch switching command is output. As a result, the necessity of switching is determined based on the operation determination voltage signal obtained by removing the steep voltage fluctuation component from the effective value signal, so that unnecessary switching of the switch is suppressed.
Further, in the present invention, since the effective value signal during the predetermined period is filtered, more voltage fluctuation components are removed as the predetermined period is longer, and unnecessary switching of the switch is reduced. Further, in order to determine the necessity of switching the switch based on the operation determination voltage signals output by each of the plurality of digital filters, any voltage fluctuation component is removed by appropriately selecting the filtering period of each digital filter. Therefore, the switching of the switch is more preferably performed.

The voltage adjusting system according to the present invention includes the above-mentioned voltage adjusting device, the switch, and a reactor or a capacitor connected in parallel to the power transmission line via the switch.

In the present invention, a voltage adjusting device capable of appropriately adjusting the voltage of a power transmission line while suppressing unnecessary switch switching is applied to a voltage adjusting system.

According to the present invention, it is possible to appropriately adjust the voltage of the power transmission line while suppressing unnecessary switch switching.

It is a block diagram which shows the structural example of the voltage adjustment system which concerns on Embodiment 1. FIG. It is a flowchart which shows the processing procedure of the CPU which executes the voltage adjustment processing of a distribution line in the voltage adjustment system which concerns on Embodiment 1. It is a block diagram which shows the structural example of the voltage adjustment system which concerns on Embodiment 2. A is a characteristic diagram showing the frequency characteristics of the digital low-pass filter of Specific Example 1 in the voltage adjusting device according to the modified example, and B is a characteristic diagram showing the step response characteristics. A is a characteristic diagram showing the frequency characteristics of the digital bandpass filter of Specific Example 1 in the voltage adjusting device according to the modified example, and B is a characteristic diagram showing the step response characteristics. A is a characteristic diagram showing the frequency characteristics of the digital low-pass filter of Specific Example 2 in the voltage adjusting device according to the modified example, and B is a characteristic diagram showing the step response characteristics. A is a characteristic diagram showing the frequency characteristics of the digital bandpass filter of Specific Example 2 in the voltage adjusting device according to the modified example, and B is a characteristic diagram showing the step response characteristics. It is a flowchart which shows the processing procedure of the CPU which executes the voltage adjustment processing of a distribution line in the voltage adjustment system which concerns on Embodiment 3. A is a graph showing the time transition of the voltage of the distribution line 201 before adjustment, B is a graph showing the time transition of the voltage of the distribution line 201 after adjustment by the conventional method, and C is the opening and closing of the reactor L1 by the conventional method. It is a graph which shows the time transition of. A is a graph showing the time transition of the operation judgment voltage signal VTp output by the digital filter, B is a graph showing the time transition of the voltage of the distribution line 201 adjusted by the voltage adjustment system 100, and C is the reactor L1 by the voltage adjustment system 100. It is a graph which shows the time transition of opening and closing of.

Hereinafter, the present invention will be described in detail with reference to the drawings showing the embodiments thereof.
(Embodiment 1)
FIG. 1 is a block diagram showing a configuration example of the voltage adjustment system according to the first embodiment. In the voltage adjustment system 100, the shunt reactors L1 and L2 (hereinafter, simply referred to as reactors L1 and L2) and the reactors L1 and L2 are connected in parallel to the distribution line 201 that transmits the three-phase power from the substation 200. It is configured to include switches S1 and S2 to be connected and a voltage adjusting device 10 for controlling switching of the switches S1 and S2. The distribution line 201 may be another power transmission line such as a transmission line or a drop line connected to the power system.

The voltage adjustment system 100 corresponds to the so-called SSR. The numbers of the reactors L1 and L2 and the switches S1 and S2 are not limited to two. When the voltage adjusting system 100 includes one reactor L1 and one switch S1, the voltage adjusting system 100 corresponds to ShR.

The reactors L1 and L2 have capacities of 150 kvar and 300 kvar, respectively. One end of the reactors L1 and L2 is connected to, for example, a neutral point. The switches S1 and S2 are, for example, an electromagnetic contactor (MC). By controlling the switching of the switches S1 and S2 by the switching command from the voltage adjusting device 10, a reactor having a capacity of 0 kvar, 150 kvar, 300 kvar or 450 kvar is put into the distribution line 201. The switching command here refers to a combination of signals for turning on / off the switches S1 and S2, respectively.

The voltage adjusting device 10 includes a detection unit 21 that detects the voltage of the distribution line 201 and a control unit 1 that controls switching of the switches S1 and S2 based on the result of taking in the voltage detected by the detection unit 21 and calculating the voltage. Be prepared. The detection unit 21 detects the voltage via the voltage transformer 20 that steps down the voltage of the distribution line 201.

The control unit 1 has a CPU (Central Processing Unit) 11 that controls the entire device. The CPU 11 is bus-connected to a ROM (Read Only Memory) 12 for storing information such as a control program, a RAM (Random Access Memory) 13 for storing temporarily generated information, and a timer 14 for measuring elapsed time and the like. ing. The control unit 1 may be configured to include a microcomputer having a CPU. The CPU 11 or the microcomputer may be configured to execute a computer program for which processing procedures are predetermined.

The CPU 11 is also bus-connected to an A / D conversion unit 15 that takes in the detection result from the detection unit 21 and performs A / D conversion, and an output unit 16 that outputs a switching command of the switches S1 and S2. The output unit 16 latches (holds) the output switching command until the output of the next switching command, but when the switches S1 and S2 operate, for example, the toggle operation, the switching command is not latched. You may.

The A / D conversion unit 15 digitizes (converts into a digital signal) the voltage of the distribution line 201 detected by the detection unit 21. The A / D conversion unit 15 samples and quantizes the detection result of the detection unit 21 which is an analog signal every predetermined period Tss (for example, 0.1 second) and converts it into a digital signal. The CPU 11 may realize the function of the A / D conversion unit 15 by taking in the detection result of the detection unit 21 and sampling and quantizing it.

The CPU 11 of the control unit 1 configured as described above calculates the voltage of the distribution line 201 based on the result of performing calculations, filtering, determination, and the like based on the voltage digitized by the A / D conversion unit 15. A switching command is output using the output unit 16 for proper adjustment. That is, the CPU 11 realizes the functions of the effective value calculation unit, the digital filter, the determination unit, and the switching command unit by executing the computer program stored in the ROM 12.

The effective value calculation unit calculates the effective value of the voltage digitized by the A / D conversion unit 15 for each period Tss in a predetermined sampling period Ts (Ts = J × Tss: J is an integer of 2 or more, for example, J = 10. ), And the calculated effective value of the voltage is output as the effective value signal Vs.

The digital filter cumulatively performs filtering processing based on a predetermined calculation formula for the effective value signal Vs output by the effective value calculation unit for a predetermined period Tperiod, thereby causing voltage fluctuations irregularly in the distribution line 201. Removes the steep voltage fluctuation component contained in.

Specifically, the digital filter is effective by performing the calculation shown in the following equation (7) using the above-mentioned effective value signal Vs, sampling period Ts, and predetermined period Tperiod with the Z conversion operator as Z. The operation judgment voltage signal VTp obtained by removing the steep voltage fluctuation component from the value signal Vs is calculated and output. Nperiod in the following equation (7) represents the number of sampling data during a predetermined period Tperiod. The degree to which the voltage fluctuation is removed (the degree of smoothing) changes according to the length of the Tperiod for a predetermined period. That is, the longer the predetermined period Tperiod, the more abrupt voltage fluctuation components are removed, and the fluctuation of the operation determination voltage signal VTp becomes smaller (the degree of smoothing is larger). On the other hand, as the predetermined period Tperiod is shorter, less abrupt voltage fluctuation components are removed and the fluctuation of the operation determination voltage signal VTp becomes larger (the degree of smoothing is smaller).

The determination unit determines whether or not the switches S1 and S2 need to be switched according to whether or not the operation determination voltage signal VTp output by the digital filter deviates from a predetermined dead zone region including a preset reference voltage. To do. This dead zone region is a voltage region between an upper limit threshold value and a lower limit threshold value for determining whether or not switching of the switches S1 and S2 is necessary based on the operation determination voltage signal VTp. For example, when the reference voltage is 6600 [V] and the width of the dead zone region centered on the reference voltage is ± 1.5%, the lower limit of the dead zone region is 6501 [V] and the upper limit is 6699 [V]. ]. Therefore, the case where the operation determination voltage signal VTp deviates from the dead zone region is either the case where the operation determination voltage signal VTp is larger than the upper limit value of the dead zone region or the case where it is smaller than the lower limit value.

Specifically, when the operation determination voltage signal VTp is larger than the upper limit value of the dead zone region, the determination unit determines that the switches S1 and S2 need to be switched in order to lower the voltage of the distribution line 201. Further, when the operation determination voltage signal VTp is smaller than the lower limit value of the dead zone region, the determination unit determines that the switches S1 and S2 need to be switched in order to raise the voltage of the distribution line 201. Then, when the operation determination voltage signal VTp does not satisfy both of these, that is, when it is within the range between the upper limit value and the lower limit value of the dead zone region (within the dead zone region), the determination unit switches the switches S1 and S2. Judge that it is not necessary (not necessary).

The frequency with which the operation determination voltage signal VTp deviates from the dead zone region differs depending on the predetermined period Tperiod and the set range of the dead zone region. Specifically, the longer the predetermined period Tperiod (the greater the degree of smoothing) and the wider the dead zone region, the more difficult it is for the operation determination voltage signal VTp to deviate from the dead zone region, and the switches S1 and S2 are switched. Although the number of times can be suppressed, the voltage of the distribution line 201 may deviate from the appropriate range. On the other hand, the shorter the predetermined period Tperiod (the smaller the degree of smoothing) and the narrower the dead zone region, the easier it is for the operation determination voltage signal VTp to deviate from the dead zone region, and the voltage of the distribution line 201 falls within the appropriate range. Deviation can be suppressed, but the number of times the switches S1 and S2 are switched increases. Therefore, the length of the predetermined period Tperiod (degree of smoothing) and the dead zone are comprehensively taken into consideration, such as suppressing the deviation of the voltage of the distribution line 201 from the dead zone region and suppressing the switching of the switches S1 and S2. The size of the range of the area may be set.

The switching command unit outputs a switching command instructing switching of the switches S1 and S2 from the output unit 16 based on the determination result of the determination unit. As a result, the switches S1 and S2 are switched, the reactors L1 and L2 connected in parallel to the distribution line 201 are changed, and the voltage of the distribution line 201 is adjusted. Specifically, when the switching command unit switches the switches S1 and S2 to raise the voltage of the distribution line 201 based on the determination result of the determination unit, the switching command unit switches so as to reduce the capacity of the reactor connected to the distribution line 201 by one step. Output the command. Further, when the switches S1 and S2 are switched to lower the voltage of the distribution line 201 based on the judgment result of the judgment unit, the switching command unit outputs a switching command so as to increase the capacity of the reactor connected to the distribution line 201 by one step. To do. On the other hand, when the switches S1 and S2 are not switched based on the determination result of the determination unit, the switching command unit does not output a new switching command, so that the switching command is held unchanged. It should be noted that a switching command may be output such that the capacity of the reactor connected to the distribution line 201 is increased or decreased by a plurality of steps.

Next, the operation of the control unit 1 of the voltage adjusting device 10 according to the first embodiment configured as described above will be described with reference to a flowchart showing the operation. The processing shown below is executed by the CPU 11 according to the control program stored in the ROM 12 in advance. FIG. 2 is a flowchart showing a processing procedure of the CPU 11 that executes the voltage adjusting process of the distribution line 201 in the voltage adjusting system 100 according to the first embodiment. The process of FIG. 2 is started in the sampling cycle Ts after the initialization of the CPU 11. The timer 14 is used when measuring Ts and Tss described later.

When the process of FIG. 2 is activated, the CPU 11 applies the voltage of the distribution line 201, which is the detection result of the detection unit 21, to the A / D conversion unit 15 only J times in the periodic Tss (Tss = Ts / J). The / D conversion is performed (S11), and the effective value of the conversion result of J times is calculated (S12: corresponding to the effective value calculation unit). The effective value signal Vs of the calculation result is stored (output) in, for example, the RAM 13.

Next, the CPU 11 performs a filtering process for removing a steep voltage fluctuation component from the effective value signal Vs by calculating the above equation (7) using the stored effective value signal Vs (S13: corresponding to a digital filter). .. The operation determination voltage signal VTp of the processing result is stored (output) in, for example, the RAM 13.

Next, the CPU 11 compares the operation determination voltage signal VTp of the stored processing result with the upper limit value and the lower limit value of the dead zone region (S15), and determines whether or not the switches S1 and S2 need to be switched according to the comparison result. (S16: Corresponds to the determination unit). Specifically, when the operation determination voltage signal VTp is larger than the upper limit value of the dead zone region, the CPU 11 determines that the switches S1 and S2 need to be switched in order to lower the voltage of the distribution line 201. Further, when the operation determination voltage signal VTp is smaller than the lower limit value of the dead zone region, the CPU 11 determines that the switches S1 and S2 need to be switched in order to raise the voltage of the distribution line 201.

If the operation determination voltage signal VTp is within the dead zone region, the CPU 11 determines that the switches S1 and S2 do not need to be switched (S16: NO), and does not output a new switching command. The process of FIG. 2 is completed. In this case, the switching command from the output unit 16 is held as before, and the switches S1 and S2 are not switched.

On the other hand, when it is determined that the switches S1 and S2 need to be switched (S16: YES), the CPU 11 changes the switching command of the switches S1 and S2 so that the voltage of the distribution line 201 approaches the reference voltage from the output unit 16. Output (S17: corresponding to the switching command unit), and the process of FIG. 2 is completed. The voltage of the distribution line 201 is adjusted by switching the switches S1 and S2 based on this switching command.

More specifically, when it is determined in step S16 that the switches S1 and S2 need to be switched in order to lower the voltage of the distribution line 201, the CPU 11 increases the capacity of the reactor connected to the distribution line 201 by one step. The switching command is changed to and output. Based on this switching command, the switches S1 and S2 are switched, and the capacity of the reactor connected to the distribution line 201 is increased by one step, so that the voltage of the distribution line 201 is lowered by one step. Further, in step S16, when it is determined that the switches S1 and S2 need to be switched in order to raise the voltage of the distribution line 201, the CPU 11 issues a switching command so as to lower the capacity of the reactor connected to the distribution line 201 by one step. Change and output. Based on this switching command, the switches S1 and S2 are switched, and the capacity of the reactor connected to the distribution line 201 is lowered by one step, so that the voltage of the distribution line 201 is raised by one step.

The CPU 11 of the voltage adjusting device 10 calculates the operation determination voltage signal VTp from the voltage of the distribution line 201 by repeating the above-mentioned voltage adjustment process, and based on the calculated operation determination voltage signal VTp, the switches S1 and S2 Control switching. As a result, the voltage of the distribution line 201 is automatically adjusted so as to be within an appropriate range. Of the processes shown in FIG. 2, the processes of steps S11 to S12 and the processes of steps S13 to S17 are separated into two different processing routines (tasks), so that the A / D conversion process and the effective value calculation process are performed. It is preferable to execute the filtering process, the determination process, and the output process in parallel.

As described above, according to the first embodiment, the voltage of the distribution line 201 is sampled and A / D converted, and the effective value signal Vs of the converted voltage is filtered by a digital filter to generate an operation determination voltage signal VTp. .. Then, when it is determined that the switches S1 and S2 for connecting the reactors L1 and L2 in parallel to the distribution line 201 need to be switched based on the generated operation determination voltage signal VTp, a switching command for the switches S1 and S2 is output. To do. Therefore, since the necessity of switching is determined based on the operation determination voltage signal VTp in which the steep voltage fluctuation component is removed from the effective value signal Vs, unnecessary switching of the switches S1 and S2 can be suppressed. If the number of switchings can be suppressed, the life of the switches S1 and S2 can be extended.

(Embodiment 2)
In the first embodiment, it is determined whether or not the switches S1 and S2 for connecting the reactors L1 and L2 in parallel to the distribution line 201 need to be switched, and a switching command is output. On the other hand, in the second embodiment, the necessity of switching the switches S1, S2 and S3 for connecting the phase-advancing capacitor (hereinafter, simply referred to as a capacitor) in parallel to the distribution line 201 is determined and a switching command is output. To do.

FIG. 3 is a block diagram showing a configuration example of the voltage adjustment system according to the second embodiment. The voltage adjustment system 100a controls switching between the capacitors C1, C2 and C3, the switches S1, S2 and S3 for connecting the capacitors C1, C2 and C3 to the distribution line 201 in parallel, and the switches S1, S2 and S3. It is configured to include the voltage adjusting device 10. One end of each of the switches S1, S2 and S3 is connected to the distribution line 201 via reactors 31, 32 and 33 for preventing the inrush current of the capacitors C1, C2 and C3 and suppressing the high frequency current. The voltage adjustment system 100a corresponds to the so-called SSC.

The capacitors C1, C2, and C3 have, for example, 100 kvar, 200 kvar, and 300 kvar, respectively, in capacitance. One end of the capacitors C1, C2 and C3 is connected to, for example, a neutral point. The reactors 31, 32, and 33 have capacities of, for example, 6 kvar, 12 kvar, and 18 kvar, respectively. By controlling the switching of the switches S1, S2, and S3 by the switching command from the voltage adjusting device 10, a capacitor having a capacity of 0kvar, 100kvar, 200kvar, 300kvar, 400kvar, 500kvar, or 600kvar is put into the distribution line 201. The switching command here refers to a combination of signals for turning on / off the switches S1, S2, and S3, respectively.

Among the functions realized by the CPU 11 by executing the computer program stored in the ROM 12, the effective value calculation unit, the digital filter, and the determination unit are the same as those in the first embodiment, and only the switching command unit is different. In addition, the parts corresponding to the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

The switching command unit outputs a switching command instructing switching of the switches S1, S2, and S3 from the output unit 16 based on the determination result of the determination unit. As a result, the switches S1, S2 and S3 are switched, the capacitors C1, C2 and C3 connected in parallel to the distribution line 201 are changed, and the voltage of the distribution line 201 is adjusted. Specifically, when the switching command unit switches the switches S1, S2, and S3 to increase the voltage of the distribution line 201 based on the determination result of the determination unit, the switching command unit increases the capacity of the capacitor connected to the distribution line 201 by one step. A switching command is output to. Further, when the switches S1, S2, and S3 are switched to lower the voltage of the distribution line 201 based on the judgment result of the judgment unit, the switching command unit gives a switching command to lower the capacity of the capacitor connected to the distribution line 201 by one step. Is output. On the other hand, when the switches S1, S2, and S3 are not switched based on the determination result of the determination unit, the switching command unit does not output a new switching command, so that the switching command is held unchanged. It should be noted that a switching command may be output so that the capacity of the capacitor connected to the distribution line 201 is increased or decreased by a plurality of steps.

Among the operations of the control unit 1 of the voltage adjusting device 10 according to the second embodiment configured as described above, the flowchart showing the processing procedure of the CPU 11 that executes the voltage adjusting processing of the distribution line 201 is the diagram of the first embodiment. It is the same as that shown in 2. However, only the processing content of step S17 corresponding to the switching command unit is different.

Specifically, when it is determined in step S16 that the switches S1, S2, and S3 need to be switched in order to lower the voltage of the distribution line 201, the CPU 11 lowers the capacity of the capacitor connected to the distribution line 201 by one step. The switching command is changed and output as described above (S16). Based on this switching command, the switches S1, S2, and S3 are switched, and the capacity of the capacitor connected to the distribution line 201 is lowered by one step, so that the voltage of the distribution line 201 is lowered by one step. Further, in step S16, when it is determined that the switches S1, S2, and S3 need to be switched in order to increase the voltage of the distribution line 201, the CPU 11 switches so as to increase the capacity of the capacitor connected to the distribution line 201 by one step. The command is changed and output (S16). Based on this switching command, the switches S1, S2, and S3 are switched, and the capacity of the capacitor connected to the distribution line 201 is increased by one step, so that the voltage of the distribution line 201 is increased by one step.

As described above, according to the second embodiment, the voltage of the distribution line 201 is sampled and A / D converted, and the effective value signal Vs of the converted voltage is filtered by a digital filter to generate an operation determination voltage signal VTp. .. Then, when it is determined that the switches S1, S2 and S3 for connecting the capacitors C1, C2 and C3 in parallel to the distribution line 201 need to be switched based on the generated operation determination voltage signal VTp, the switches S1, S2 and S2 The switching command of S3 is output. Therefore, since the necessity of switching is determined based on the operation determination voltage signal VTp in which the steep voltage fluctuation component is removed from the effective value signal Vs, unnecessary switching of the switches S1, S2, and S3 can be suppressed. If the number of switchings can be suppressed, the life of the switches S1, S2, and S3 can be extended.

Further, according to the first embodiment (or the second embodiment), since the effective value signal Vs during the predetermined period is filtered, the longer the predetermined period, the more the voltage fluctuation component is removed, and the switch S1 , S2 (or S1, S2, S3) are less unnecessary to switch.

Further, according to the first embodiment or the second embodiment, when the operation determination voltage signal VTp deviates from the dead zone region, the switching command is output in a quick response, so that the voltage of the distribution line 201 deviates from the appropriate range. Can be suppressed.

Further, according to the first embodiment (or the second embodiment), the operation determination voltage signal is calculated by the filtering process represented by the equation (7). Therefore, since the necessity of switching is determined based on the operation determination voltage signal VTp in which the steep voltage fluctuation component is removed from the effective value signal Vs, unnecessary switching of the switches S1, S2 (or S1, S2, S3) is performed. It can be suitably suppressed.

In the determination unit of the first embodiment (or the second embodiment), the switches S1 and S2 (or S1, S2, S3) are switched when the operation determination voltage signal VTp deviates from the dead zone region. The case where it is determined that it is necessary has been described as an example, but the present invention is not limited to this. For example, the determination unit needs to switch the switches S1, S2 (or S1, S2, S3) when the period in which the operation determination voltage signal VTp input from the digital filter deviates from the dead zone region continues for a predetermined time or longer. It may be determined that there is. Further, the determination unit integrates the difference voltage between the operation determination voltage signal VTp and the dead zone region, and when the integrated value becomes a predetermined value or more, the switches S1, S2 (or S1, S2, S3) are switched. It may be determined that it is necessary. Further, when the determination unit integrates the operation determination voltage signal VTp instead of the difference voltage and the integrated value deviates from a predetermined range, it is necessary to switch the switches S1, S2 (or S1, S2, S3). May be determined. By doing so, when a plurality of voltage adjusting devices 10 are connected in series, operation hunting (a phenomenon in which unnecessary operations are repeated between the front and rear voltage adjusting devices 10) can be prevented.

Further, in the determination unit in the first embodiment (or the second embodiment), it is necessary to switch the switches S1, S2 (or S1, S2, S3) based on the operation determination voltage signal VTp from the digital filter. The case of determining the presence or absence has been described as an example, but if at least the operation determination voltage signal VTp is used to determine the necessity of switching the switches S1, S2 (or S1, S2, S3), this is used. Not limited to. For example, the determination unit monitors the voltage of the distribution line 201 detected by the detection unit 21 in addition to the operation determination voltage signal VTp, and when the operation determination voltage signal VTp deviates from the dead zone region, the voltage of the distribution line 201 changes. It may be determined that the switches S1 and S2 (or S1, S2 and S3) need to be switched when both of the cases where the voltage deviates from the dead zone region are satisfied. As the voltage of the distribution line 201 at this time, the effective value signal Vs calculated by the effective value calculation unit is used. The time determination method or the integration determination method described above may be used in determining the necessity of switching the switches S1, S2 (or S1, S2, S3) based on the voltage of the distribution line 201.

Further, in the first embodiment or the second embodiment, the reactors L1, L2 or the capacitors C1, C2, C3 pass through the switches S1, S2 or the switches S1, S2, S3 and the reactors 31, 32, 33. Although the case of being substantially connected in parallel to the distribution line 201 has been described as an example, the present invention is not limited to this. For example, the capacitors C1, C2, and C3 may be connected in parallel to the secondary winding of the transformer in which the primary winding is connected in parallel to the distribution line 201 via the switches S1, S2, and S3, respectively. Further, for example, between a tap (corresponding to a switch) of a single-winding transformer in which windings are connected in parallel to the distribution line 201 and the other end on the opposite side of one end of the winding connected to the distribution line 201. Capacitors may be connected in parallel. In this case, the primary conversion value of the capacitance of the capacitor changes according to the change in the transformation ratio due to the switching of the tap (switch).

(Modification example)
In the first embodiment, a case where the digital filter is subjected to the filtering process by using the arithmetic expression of the above equation (7) has been described as an example, but the present invention is not limited to this. For example, the following formula (8) or the following formula (9) may be used. In this case, Eqs. (8) and (9) so that the digital filter functions as a low-pass filter that passes through the low frequency band or a bandpass filter that passes only the required range of the low frequency band. Set the filter order and filter coefficient in the formula.

For example, when the above equation (8) is used as a specific example 1, the digital filter follows in 10 minutes by setting the filter order and the filter coefficient as in the following equation (8-1). It functions as a low-pass filter and removes steep voltage fluctuation components of 10 minutes or less. FIG. 4A is a characteristic diagram showing the frequency characteristics of the digital low-pass filter of the specific example 1 in the voltage adjusting device 10 according to the modified example, and FIG. 4B is a characteristic diagram showing the step response characteristics.

Further, when the above equation (8) is used, the digital filter extracts only the voltage fluctuation component for 30 seconds by setting the filter order and the filter coefficient as in the following equation (8-2). Functions as a bandpass filter. FIG. 5A is a characteristic diagram showing the frequency characteristics of the digital bandpass filter of the specific example 1 in the voltage adjusting device 10 according to the modified example, and FIG. 5B is a characteristic diagram showing the step response characteristics.

On the other hand, when the above equation (9) is used as a specific example 2, the digital filter follows the 540th order in 10 minutes by setting the filter order and the filter coefficient as in the following equation (9-1). It functions as a low-pass filter and removes steep voltage fluctuation components of 10 minutes or less. FIG. 6A is a characteristic diagram showing the frequency characteristics of the digital low-pass filter of Specific Example 2 in the voltage adjusting device 10 according to the modified example, and FIG. 6B is a characteristic diagram showing the step response characteristics. The coefficient Xi is a coefficient at which the digital filter has the frequency characteristic shown in A of FIG. 6 and the step response characteristic shown in B of FIG. Further, the filter order at this time is a degree calculated by setting the sampling period to 1 [s], and when it is actually applied, it may be a huge calculation. Therefore, the sampling period Ts is increased, etc. It is preferable to take measures against.

Further, when the above equation (9) is used, the digital filter extracts only the voltage fluctuation component for 30 seconds by setting the filter order and the filter coefficient as in the following equation (9-2). Functions as a bandpass filter. FIG. 7A is a characteristic diagram showing the frequency characteristics of the digital bandpass filter of Specific Example 2 in the voltage adjusting device 10 according to the modified example, and FIG. 7B is a characteristic diagram showing the step response characteristics. The coefficient Xi is a coefficient that the digital filter has the frequency characteristic shown in A of FIG. 7 and the step response characteristic shown in B of FIG.

As described above, by setting the filter order and filter coefficient of Eq. (8) or Eq. (9) so that the digital filter functions as a low-pass filter or bandpass filter, instead of Eq. (7), (8) Equation or equation (9) may be substituted. However, when the arithmetic expression of the equation (7) is used for the digital filter, it is not necessary to set the filter order and the filter coefficient as in the equations (8) and (9), and the design can be easily performed. On the other hand, when the calculation formula of the formula (8) or the above formula (9) is used for the digital filter, the frequency to be removed can be adjusted according to the set filter order and the filter coefficient. Therefore, when the voltage fluctuation component to be removed is known, it can be finely adjusted so as to remove only the voltage fluctuation component. Depending on the voltage adjusting device 10 to be used, either the formula (7) or the formula (9) may be used as appropriate. The filter order and filter coefficient in the equations (8-1), (8-2), (9-1), and (9-2) are examples, and are not limited to those described above.

As described above, according to this modification, the operation determination voltage signal VTp may be calculated by a filtering process using a low-pass filter or a bandpass filter represented by the equation (8) or (9). In this case, from the effective value signal Vs, a steep voltage fluctuation component within a time corresponding to the filter order and the filter coefficient is removed, or only a voltage fluctuation component with a time corresponding to the filter order and the filter coefficient is passed. be able to.

(Embodiment 3)
The first embodiment determines the necessity of switching the switches S1 and S2 based on the operation determination voltage signal VTp output by the digital filter, whereas the third embodiment has two different digital filters. Is a form in which the necessity of switching of the switches S1 and S2 is determined based on the operation determination voltage signal output by each. The CPU 11 further realizes the functions of the second digital filter and the second determination unit by executing the computer program stored in the ROM 12.

In the voltage adjusting device 10 according to the first embodiment, the filtering process performed by the digital filter can remove the voltage fluctuation component that is steep in the predetermined period Tperiod, but in the actual system, the voltage fluctuation due to various factors exists. doing. For example, sudden fluctuations (fluctuations) may occur in a short period of time. In such a situation, in the digital filter according to the first embodiment, in order to remove the steep voltage fluctuation in the predetermined period Tperiod, the steep voltage fluctuation in the short period as compared with the period Tperiod is removed by the filtering process. It may end up. Therefore, in the first embodiment, there is a possibility that sudden fluctuations that adversely affect the equipment connected to the distribution line 201 may be ignored, and in this case, the switches S1 and S2 are not switched. Therefore, in the third embodiment, a second digital filter different from the above digital filter is further added so as to cope with a sudden voltage fluctuation in a short period of time.

Since the block configuration of the voltage adjustment system according to the third embodiment is the same as that of the voltage adjustment system 100 according to the first embodiment, the illustration is omitted, and the same reference numerals are given to the parts corresponding to the first embodiment. The explanation will be omitted.

The second digital filter takes the effective value signal Vs as an input, and removes a steep voltage fluctuation component in the second period Tbase shorter than the predetermined period Tperiod filtered in the first embodiment from the effective value signal Vs. To do.

Specifically, the second digital filter performs the calculation shown in the following equation (10) using the above-mentioned effective value signal Vs, sampling period Ts, second period Tbase, and Z-transform operator Z. The second operation determination voltage signal VTb obtained by removing the steep voltage fluctuation component from the effective value signal Vs is calculated and output. Nbase in the following equation (10) represents the number of sampling data in the second period Tbase (Tbase <Tperiod). In the second digital filter, since the second period Tbase is shorter than the predetermined period Tperiod, the voltage fluctuation component removed is small, and the second operation determination voltage signal VTb is the operation determination voltage signal during the same period. The voltage fluctuation is large (the degree of smoothing is small) as compared with VTp.

In the second digital filter as well, the filtering process may be performed by using the arithmetic expression shown in the following equation (11) or the following equation (12) as in the digital filter of the first embodiment. However, when the calculation formula of the above formula (10) is used for the second digital filter, the second digital fill is easier than the case of using the calculation formula of the following formula (11) or the following formula (12). Can be designed to.

The second determination unit operates when the second operation determination voltage signal VTb output by the second digital filter deviates from the second dead zone region including the preset reference voltage. It is determined that the switches S1 and S2 need to be switched regardless of the determination result based on the determination voltage signal VTp. This second dead zone region is a voltage region between the upper limit threshold value and the lower limit threshold value for determining whether or not the switches S1 and S2 need to be switched based on the second operation determination voltage signal VTb. Is.

Specifically, when the second operation determination voltage signal VTb is larger than the upper limit value of the second dead zone region, the second determination unit needs to switch the switches S1 and S2 in order to lower the voltage of the distribution line 201. Judge that there is. Further, when the second operation determination voltage signal VTb is smaller than the lower limit value of the second dead zone region, the second determination unit determines that the switches S1 and S2 need to be switched in order to raise the voltage of the distribution line 201. To do. Then, when the second operation determination voltage signal VTb does not satisfy both of these, that is, when it is within the range of the upper limit value and the lower limit value of the second dead zone region (within the second dead zone region), it continues. The determination unit determines whether or not the switches S1 and S2 need to be switched based on whether or not the operation determination voltage signal VTp deviates from the dead zone region. The processing content of the determination unit is the same as that of the first embodiment.

As in the first embodiment, the size of the second dead zone region is widened by comprehensively considering the effects of suppressing the voltage deviation of the distribution line 201 from the dead zone region and suppressing the switching of the switches S1 and S2. , And the length (degree of smoothing) of the second period Tbase may be set.

The switching command unit outputs a switching command instructing switching of the switches S1 and S2 from the output unit 16 based on the determination results of the determination unit and the second determination unit. Specifically, when the switching command unit switches the switches S1 and S2 to raise the voltage of the distribution line 201 based on the determination result of the determination unit or the second determination unit, the switching command unit determines the capacity of the reactor connected to the distribution line 201. A switching command is output so as to lower the voltage by one step. Further, when the switching command unit switches the switches S1 and S2 to lower the voltage of the distribution line 201 based on the judgment result of the judgment unit or the second determination unit, the switching command unit raises the capacity of the reactor connected to the distribution line 201 by one step. The switching command is output as follows. On the other hand, when the switches S1 and S2 are not switched based on the determination results of the determination unit and the second determination unit, the changeover command unit holds the changeover command unchanged.

Next, the operation of the control unit 1 of the voltage adjusting device 10 according to the third embodiment configured as described above will be described with reference to a flowchart showing the operation. FIG. 8 is a flowchart showing a processing procedure of the CPU 11 that executes the voltage adjusting process of the distribution line 201 in the voltage adjusting system 100 according to the third embodiment. The process of FIG. 8 is started in the above-mentioned sampling cycle Ts after the initialization of the CPU 11.

Since the processing contents of steps S21 to 23 and steps S29 and S27 shown in FIG. 8 are the same as steps S11 to 13 and steps S16 and S17 shown in FIG. 2 of the first embodiment, a part of the description thereof will be omitted. .. Hereinafter, the filtering by the digital filter used in the first embodiment is referred to as a first filtering process, and the filtering by the second digital filter is referred to as a second filtering process.

When the process of FIG. 8 is activated, the CPU 11 applies the voltage of the distribution line 201, which is the detection result of the detection unit 21, to the A / D conversion unit 15 J times (J = Ts / Tss) in the periodic Tss. The / D conversion is performed (S21), the effective value of the conversion result J times is calculated (S22: corresponding to the effective value calculation unit), and the effective value signal Vs of the calculation result is stored in the RAM 13.

Next, the CPU 11 performs the first filtering process (S23: corresponding to a digital filter) by calculating the above-mentioned equation (7) using the stored effective value signal Vs, and the operation determination voltage is obtained as the first processing result. The signal VTp is calculated and stored in the RAM 13. Further, the CPU 11 performs the second filtering process (S24: corresponding to the second digital filter) by calculating the above-mentioned equation (10) using the stored effective value signal Vs, and the second processing result is the second. The operation determination voltage signal VTb of 2 is calculated and stored in the RAM 13.

Next, the CPU 11 compares the second operation determination voltage signal VTb, which is the stored second processing result, with the upper limit value and the lower limit value of the second dead zone region (S25), and switches S1 according to the comparison result. , S2 is determined to be necessary (S26: corresponding to the second determination unit). Specifically, when the second operation determination voltage signal VTb is larger than the upper limit value of the second dead zone region, the CPU 11 determines that the switches S1 and S2 need to be switched in order to lower the voltage of the distribution line 201. .. Further, when the second operation determination voltage signal VTb is smaller than the lower limit value of the second dead zone region, the CPU 11 determines that the switches S1 and S2 need to be switched in order to raise the voltage of the distribution line 201.

In any of the above cases, when the second operation determination voltage signal VTb is in the second dead zone region (S26: NO), the CPU 11 has the operation determination voltage signal VTp, which is the stored first processing result, and the dead zone. The upper limit value and the lower limit value of the region are compared (S28), and the necessity of switching the switches S1 and S2 is determined according to the comparison result (S29: corresponding to the determination unit). When the operation determination voltage signal VTp is in the dead zone region, the CPU 11 determines that switching of the switches S1 and S2 is unnecessary (S29: NO), and ends the process of FIG. 8 without newly outputting a switching command. To do.

On the other hand, when it is determined in step S26 that the switches S1 and S2 need to be switched (S26: YES), or when it is determined in step S29 that the switches S1 and S2 need to be switched (S29: YES), the CPU 11 determines. The switching command of the switches S1 and S2 is changed so that the voltage of the distribution line 201 approaches the reference voltage, and the output is output from the output unit 16 (S27: corresponding to the switching command unit), and the process of FIG. 8 is completed.

The CPU 11 of the voltage adjusting device 10 calculates the operation determination voltage signal VTp and the second operation determination voltage signal VTb from the voltage of the distribution line 201 by repeating the above-mentioned voltage adjustment process, and calculates the operation determination voltage signal VTp and the second operation determination voltage signal VTp. The switching of the switches S1 and S2 is controlled based on the operation determination voltage signal VTb of 2. As a result, the voltage of the distribution line 201 is automatically adjusted so as to be within an appropriate range.

In the third embodiment, the case where two types of digital filters are realized by the CPU 11 has been described as an example, but the present invention is not limited to this, and even if a plurality of types of digital filters are realized. Good. In this case, since an arbitrary voltage fluctuation component is removed by setting the filtering period of each digital filter to be different, the switches S1 and S2 are appropriately switched in response to various voltage fluctuation components. be able to.

As described above, according to the third embodiment, the switch S1 is based on the second operation determination voltage signal VTb output by filtering the effective value signal Vs in the second period Tbase shorter than the predetermined period Tperiod. When it is determined that switching between S2 and S2 is necessary, a switching command for switches S1 and S2 is further output. Therefore, even if it is determined that switching of the switches S1 and S2 is unnecessary based on the operation determination voltage signal VTp output during the predetermined period Tperiod, in response to a sudden voltage fluctuation during the second period Tbase. The switches S1 and S2 can be switched.

Further, according to the third embodiment, when the second operation determination voltage signal deviates from the second dead zone region, a switching command is output in a quick response, so that the voltage of the distribution line 201 deviates from the appropriate range. Can be suppressed.

Further, according to the third embodiment, the second operation determination voltage signal is calculated by the filtering process represented by the equation (10), and therefore, the steep voltage fluctuation component is removed from the effective value signal Vs. Since the necessity of switching is determined based on the operation determination voltage signal VTb of the above, unnecessary switching of the switches S1 and S2 can be suitably suppressed.

Further, according to the third embodiment, the second operation determination voltage signal VTb may be calculated by a filtering process using a low-pass filter or a band-pass filter represented by the equation (11) or the equation (12). .. In this case, from the effective value signal Vs, a steep voltage fluctuation component within a time corresponding to the filter order and the filter coefficient is removed, or only a voltage fluctuation component with a time corresponding to the filter order and the filter coefficient is passed. be able to.

Further, according to the third embodiment, it may be determined whether or not the switches S1 and S2 need to be switched based on the operation determination voltage signals output by each of the plurality of digital filters. In this case, by appropriately selecting the filtering period of each digital filter, any voltage fluctuation component is removed, so that the switches S1 and S2 can be switched more preferably.

Further, according to the first, second, third, or modified examples, the voltage adjusting system 100 or the voltage adjusting device 10 capable of appropriately adjusting the voltage of the distribution line 201 while suppressing unnecessary switch switching. It can be applied to 100a.

Hereinafter, the result of comparing and verifying the case where the voltage of the distribution line 201 is adjusted by the voltage adjusting system 100 according to the first embodiment and the case where the voltage is adjusted by the conventional time determination method by simulation will be described. The voltage adjustment system 100 uses a digital filter that performs the calculation shown in the equation (7), switches the switch S1 to turn on / off the reactor L1, that is, operates as a ShR. The analysis conditions are as follows.

(A) Voltage sampling cycle Ts: 1 second (b) Reference voltage: 6600V
(C) Width of dead zone region with respect to reference voltage: 1.5% (± 99V)
(D) Control amount by turning on / opening the reactor L1: 100V
(E) Operation time of time control by the conventional time determination method: 15 seconds (f) Predetermined period in digital filtering processing Tperiod: 120 seconds

FIG. 9A is a graph showing the time transition of the voltage of the distribution line 201 before adjustment, B is a graph showing the time transition of the voltage of the distribution line 201 after adjustment by the conventional method, and C is the graph of the reactor L1 by the conventional method. It is a graph which shows the time transition of opening and closing. FIG. 10A is a graph showing the time transition of the operation determination voltage signal VTp output by the digital filter, B is a graph showing the time transition of the voltage of the distribution line 201 after adjustment by the voltage adjustment system 100, and C is the voltage adjustment system 100. It is a graph which shows the time transition of opening and closing of the reactor L1 by.

The horizontal axis of each graph in FIGS. 9 and 10 represents time (s), and the vertical axis represents the voltage (kV) or the open / closed state of the reactor L1. The broken lines shown in A and B in FIG. 9 and A and B in FIG. 10 are the upper limit voltage and the lower limit voltage of the dead zone region. The broken line shown in FIG. 10A is the time transition of the temporary operation determination voltage signal before the reactor L1 is opened / closed, and the solid line is the actual operation determination voltage signal VTp after the reactor L1 is opened / closed. It is the time transition of.

As a result of the simulation, the number of control times (the number of times the switch S1 is switched) in 16000 seconds is reduced from 56 times according to the conventional time determination method to 20 times according to the voltage adjustment system 100. Therefore, in the voltage adjusting system 100, it was shown that the switching of the switch S1 is preferably suppressed as compared with the conventional one. Hereinafter, it will be described with reference to FIGS. 9 and 10.

As shown in A of FIG. 9, the voltage of the distribution line 201 before adjustment is generally about 100 V higher than the reference voltage, and fluctuates due to voltage fluctuations having a relatively short period. As a result of adjusting this voltage by the time determination method, as shown in B of FIG. 9, although the adjusted voltage is adjusted so as to almost match the reference voltage on average, it is relatively short (however, the operation). It can be seen that the dead zone region is frequently deviated in a cycle (longer than the time limit). Therefore, as shown in C of FIG. 9, the reactor L1 is charged and opened in a relatively short cycle.

On the other hand, as shown in FIG. 10A, in the operation determination voltage signal VTp in which the voltage of the distribution line 201 is subjected to A / D conversion processing, effective value calculation processing, and filtering processing, voltage fluctuations having a relatively short period are smoothed. You can see that there is. As a result of adjusting the voltage of the distribution line 201 based on this operation determination voltage signal VTp, as shown in FIG. 10B, the adjusted voltage is adjusted so as to substantially match the reference voltage on average. It can be seen that the deviation from the dead zone region is suppressed in a relatively short cycle. Therefore, as shown in FIG. 10C, the reactor L1 is not turned on and off in a relatively short cycle, and the total number of controls is sufficiently suppressed. Therefore, even in the result of this simulation, it can be said that the voltage adjustment system 100 suppresses unnecessary switching of the switch S1.

The embodiments disclosed this time should be considered as exemplary in all respects and not restrictive. The scope of the present invention is indicated by the scope of claims, not the above-mentioned meaning, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims. Also, the technical features described in each embodiment can be combined with each other.

1 Control unit 10 Voltage regulator 11 CPU
12 ROM
13 RAM
14 Timer 15 A / D converter 16 Output unit 20 Measurement transformer 21 Detection unit 31, 32, 33 Reactor S1, S2, S3 Switch L1, L2 Reactor C1, C2, C3 Capacitor 100, 100a Voltage adjustment system 200 Substation 201 Distribution line

Claims (11)

A voltage regulator that adjusts the voltage of the power transmission line by controlling the switching of a switch that connects a reactor or a capacitor in parallel to the power transmission line.
A detector that detects the voltage of the power transmission line and
An A / D converter that digitizes the voltage detected by the detector,
An effective value calculation unit that calculates the effective value of the digitized voltage by the A / D conversion unit and outputs an effective value signal.
A digital filter that removes a steep voltage fluctuation component from the effective value signal output by the effective value calculation unit and outputs an operation judgment voltage signal.
A determination unit that determines whether or not the switch needs to be switched based on the operation determination voltage signal output by the digital filter.
When the determination unit determines that switching is necessary, the switch is provided with a switching command unit that outputs a switching command so that the voltage of the power transmission line approaches the reference voltage .
The digital filter performs filtering processing on the effective value signal output by the effective value calculation unit during a predetermined period, and sets the effective value signal as Vs, the sampling period as Ts, and the predetermined period as Tperiod. the number of effective value signal in the predetermined period Nperiod, the Z conversion operator as Z, by performing the calculation shown in equation (1) below, the voltage regulator you calculates and outputs the operation determination voltage signal VTp apparatus.

A voltage regulator that adjusts the voltage of the power transmission line by controlling the switching of a switch that connects a reactor or a capacitor in parallel to the power transmission line.
A detector that detects the voltage of the power transmission line and
An A / D converter that digitizes the voltage detected by the detector,
An effective value calculation unit that calculates the effective value of the digitized voltage by the A / D conversion unit and outputs an effective value signal.
A digital filter that removes a steep voltage fluctuation component from the effective value signal output by the effective value calculation unit and outputs an operation judgment voltage signal.
A determination unit that determines whether or not the switch needs to be switched based on the operation determination voltage signal output by the digital filter.
When the determination unit determines that switching is necessary, the switch is provided with a switching command unit that outputs a switching command so that the voltage of the power transmission line approaches the reference voltage .
The digital filter performs filtering processing on the effective value signal output by the effective value calculation unit during a predetermined period, and sets the effective value signal as Vs, the Z conversion operator as Z, and the predetermined filter order. By setting M, N and predetermined coefficients to ai (i = 0,1, ..., M) and bj (j = 0,1, ... N) and performing the calculation shown in the following equation (2). , The operation judgment voltage signal VTp is calculated and output,
Wherein the predetermined filter order M, N and the predetermined coefficients ai, bj is a voltage regulator for the digital filter Ru is set to function as a low pass filter or a band-pass filter.

A voltage regulator that adjusts the voltage of the power transmission line by controlling the switching of a switch that connects a reactor or a capacitor in parallel to the power transmission line.
A detector that detects the voltage of the power transmission line and
An A / D converter that digitizes the voltage detected by the detector,
An effective value calculation unit that calculates the effective value of the digitized voltage by the A / D conversion unit and outputs an effective value signal.
A digital filter that removes a steep voltage fluctuation component from the effective value signal output by the effective value calculation unit and outputs an operation judgment voltage signal.
A determination unit that determines whether or not the switch needs to be switched based on the operation determination voltage signal output by the digital filter.
When the determination unit determines that switching is necessary, the switch is provided with a switching command unit that outputs a switching command so that the voltage of the power transmission line approaches the reference voltage .
The digital filter performs filtering processing on the effective value signal output by the effective value calculation unit during a predetermined period, and sets the effective value signal as Vs, the Z conversion operator as Z, and the predetermined filter order. M, the predetermined coefficient is hi (i = 0,1, ..., M), and the operation determination voltage signal VTp is calculated and output by performing the calculation shown in the following equation (3).
Wherein the predetermined filter order M and the predetermined coefficients hi, the digital filter is set Ru voltage regulator to act as a low pass filter or a band-pass filter.

A voltage regulator that adjusts the voltage of the power transmission line by controlling the switching of a switch that connects a reactor or a capacitor in parallel to the power transmission line.
A detector that detects the voltage of the power transmission line and
An A / D converter that digitizes the voltage detected by the detector,
An effective value calculation unit that calculates the effective value of the digitized voltage by the A / D conversion unit and outputs an effective value signal.
A digital filter that removes a steep voltage fluctuation component from the effective value signal output by the effective value calculation unit and outputs an operation judgment voltage signal.
A determination unit that determines whether or not the switch needs to be switched based on the operation determination voltage signal output by the digital filter.
When the determination unit determines that switching is necessary, the switch is provided with a switching command unit that outputs a switching command so that the voltage of the power transmission line approaches the reference voltage .
The digital filter performs filtering processing on the effective value signal output by the effective value calculation unit during a predetermined period, and then performs filtering processing.
A second digital filter that outputs a second operation determination voltage signal by performing filtering processing on the effective value signal output by the effective value calculation unit during the second period shorter than the predetermined period.
Further provided with a second determination unit for determining whether or not the switch needs to be switched based on the second operation determination voltage signal.
The switching instruction portion, when switched in the second determination unit determines that necessary to approximate the voltage of the power transmission line to a reference voltage, the voltage regulator you further outputs a switching command to the switch. The second determination section, when said second operation determining voltage signal deviates a predetermined second dead-band region, a voltage according to judges claim 4 that it is necessary to changeover of the switch Adjuster. The second digital filter, the effective value signal Vs, the sampling period Ts, the second Tbase period, a Z conversion operator as Z, by performing the calculation shown in the following equation (4), The voltage adjusting device according to claim 4 or 5 , which calculates and outputs the second operation determination voltage signal VTb.

In the second digital filter, the effective value signal is Vs, the Z-transform operator is Z, the predetermined filter order is P, Q, and the predetermined coefficient is kk (k = 0,1, ..., P). By setting dl (l = 0, 1, ... Q) and performing the calculation shown in the following equation (5), the second operation determination voltage signal VTb is calculated and output.
The voltage regulator according to claim 4 or 5 , wherein the predetermined filter orders P and Q and the predetermined coefficients kk and dl are set so that the digital filter functions as a low-pass filter or a band-pass filter.

In the second digital filter, the effective value signal is Vs, the Z-transform operator is Z, the predetermined filter order is P, and the predetermined coefficient is fk (k = 0,1, ..., P). By performing the calculation shown in the equation (6), the second operation determination voltage signal VTb is calculated and output.
The voltage regulator according to claim 4 or 5 , wherein the predetermined filter order P and the predetermined coefficient fk are set so that the digital filter functions as a low-pass filter or a band-pass filter.

A voltage regulator that adjusts the voltage of the power transmission line by controlling the switching of a switch that connects a reactor or a capacitor in parallel to the power transmission line.
A detector that detects the voltage of the power transmission line and
An A / D converter that digitizes the voltage detected by the detector,
An effective value calculation unit that calculates the effective value of the digitized voltage by the A / D conversion unit and outputs an effective value signal.
A plurality of digital filters that remove steep voltage fluctuation components from the effective value signal output by the effective value calculation unit and output an operation judgment voltage signal, and
Each said plurality of digital filters based on the operation judging voltage signal output, whether it is necessary to changeover of the switch and the determination unit to each other,
When the determination unit determines that switching is necessary, the switch is provided with a switching command unit that outputs a switching command so that the voltage of the power transmission line approaches the reference voltage .
The plurality of digital filters are voltage adjusting devices that perform filtering processing on effective value signals output by the effective value calculation unit during a predetermined period different from each other . The voltage adjusting device according to any one of claims 1 to 9, wherein the determination unit determines that switching of the switch is necessary when the operation determination voltage signal deviates from a preset dead zone region. .. A voltage regulator according to any one of claims 1 1 0,
With the switch
A voltage regulation system including a reactor or a capacitor connected in parallel to the power transmission line via the switch.

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