WO2016121014A1 - Voltage control device and voltage-control-device control method - Google Patents

Abstract

The present invention secures available SVC output capacity, suppresses short-period fluctuation faster than the operating time limit of an SVR and long-period fluctuation shorter than the control width of the SVR, and prevents voltage deviation. The present invention is a voltage control device for controlling the voltage of a power system, said voltage control device being provided with: a noncorrected voltage calculation unit for calculating, on the basis of system information for the power system, the system voltage, and the output of the voltage control device, a system voltage for when the voltage control device is not corrected; an other-voltage-control-device output variation prediction unit for predicting, on the basis of the system information, noncorrected voltage, and other-voltage-control-device operation parameters that are the operation parameters of another voltage control device in the power system, the amount of output variation of the other voltage control device when the voltage control device is not corrected; and a control amount calculation unit for calculating, on the basis of the system information, system voltage, and the predicted amount of output variation of the other voltage control device, a control amount for the voltage control device.

Description

Voltage control device and voltage control device control method

The present invention relates to a voltage control device for a power system that performs voltage control of the power system.

Generally, in a power system, the voltage of the power system is controlled by a voltage control device such as an SVR (Step Voltage Regulator) or an SVC (Static Var Compensator).

In voltage control in a power system, there is a technique described in Japanese Patent Application Laid-Open No. 2011-217581 (Patent Document 1) in order to realize cooperative operation between voltage control devices. In this publication, “the automatic voltage regulator for a line according to the present invention performs the switching control of the tap by monitoring the continuation state of the reactive power passing through the own device. It is possible to prevent hunting of the operation between the two, and to perform efficient voltage control in cooperation with the operation of the static reactive power compensator ”.

JP 2011-217581 A

The technique described in Patent Document 1 is based on the premise that a dead zone is set in the SVC in order to promote the operation of the SVR, and the dead zone of the SVC needs to be set larger than the dead zone of the SVR. The dead zone is a set voltage range. When the measured or calculated voltage exists in the dead zone, the voltage control device does not control the voltage. Since the SVC does not control the voltage when the voltage is within the dead band, there is no voltage margin and the voltage deviates from the appropriate range (101 ± 6V or 202 ± 20V) determined by the Electricity Business Law other than the SVC installation point. there's a possibility that.

The present invention has been made in view of the above problems, and its object is to suppress short-cycle fluctuations faster than the SVR operation time period and long-period fluctuations smaller than the SVR control width while ensuring the output capacity of the SVC. The purpose is to prevent voltage deviation.

In order to solve the above-described problem, the present invention provides a voltage control device that controls a voltage of a power system, and the voltage control device is based on system information of the power system, a system voltage, and an output of the voltage control device. Non-compensation voltage calculator that calculates a non-compensation voltage that is a system voltage at the time of no compensation, the system information, the non-compensation voltage, and other voltage control that is an operation parameter of another voltage control device in the power system Another voltage control device output change prediction unit that predicts an output change amount of the other voltage control device when the voltage control device is not compensated based on the device operation parameter, the system information, the system voltage, and the other voltage control A control amount calculation unit that calculates a control amount of the voltage control device from an output change prediction amount of the device.

According to the present invention, the SVC control amount is calculated by subtracting the voltage compensation amount expected to be generated by the output change predicted value of the SVR, thereby suppressing the output of the SVC and securing the reserve for short period fluctuations. can do. Moreover, the voltage compensation amount can be shared for each voltage control device by operating the SVR triggered by the voltage change caused by the SVC output suppression. Furthermore, even if the voltage is within the SVR dead band, the voltage is maintained at the target value by the SVC, so that a voltage margin can be secured, and it is possible to contribute to prevention of voltage deviations at points other than the installation point of the voltage control device.

It is a system configuration figure of the voltage control device in an embodiment of the invention. It is a functional lineblock diagram of a voltage control device in an embodiment of the invention. It is a schematic diagram of the electric power system which applies a voltage control apparatus. It is a processing flowchart of a voltage control apparatus. It is a schematic diagram showing the effect of a voltage control apparatus. It is a schematic diagram showing the effect of a voltage control apparatus. It is a schematic diagram showing the effect of a voltage control apparatus. It is a schematic diagram showing the effect of a voltage control apparatus. It is a functional block diagram of the voltage control apparatus in Example 2. It is a function block diagram of the voltage control apparatus in Example 3. It is a function block diagram of the voltage control apparatus in Example 4.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram illustrating an example of a system configuration in which the voltage control device is SVC and the other voltage control device is SVR. As an example, SVC was selected as the voltage control device, but high-speed power operation by power electronics control such as PCS (Power Conditioning System), UPFC (Unified Power Flow Controller), TSC (Thyristor Switched Capacitor) Or a device capable of changing the power flow state such as reactive power. Although the SVR is selected as the other voltage control device, a device that controls the voltage in multiple stages by mechanically switching a switch such as SC (Switched Capacitor) or ShR (Shunt Reactor) may be used.

The power system 101 is connected to an SVR 102, a voltage / current sensor 103, an SVC 105, and a voltage sensor 106. The SVR 102 and the voltage / current sensor 103 are connected to the SVR controller 104, and the SVC 105 and the voltage sensor 106 are connected to the SVC controller 107. The SVR controller 104 and the SVC controller 107 are configured by input means, output means, CPU, RAM, database, and program data, respectively.

FIG. 2 is a diagram illustrating an example of a functional configuration related to program data and database functions in the SVC controller 107. The SVC controller 107 includes functions of a system topology DB 201, an uncompensated voltage calculation unit 202, an SVR output change prediction unit 203, a control amount calculation unit 204, and an SVR operation parameter DB 205.

The system topology DB 201 holds the impedance of the branch in the power system 101, the connection state of the branch, and the connection information of the devices existing on the power system. The uncompensated voltage calculation unit 202 acquires the system information 206 from the system topology DB 201, the SVC output from the SVC 105, the voltage at the installation point of the SVC 105 from the voltage sensor 106, and the uncompensated voltage 207 when there is no SVC 105 output. calculate. The non-compensation voltage 207 is calculated by Equation 1, for example.

V ₀ is the uncompensated voltage 207 at the SVC 105 installation point, V is the system voltage detected by the voltage sensor 106, F is the output of the _SVC 105, and K _SVC is the control sensitivity of the _SVC 105. The control sensitivity is a differential amount of the system voltage change with respect to the output change of the voltage control device, and is uniquely obtained from the system information 206.

The SVR operation parameter DB 205 holds the same SVR operation time limit, target voltage, dead band width, and LDC parameters that the SVR controller 104 holds.

The SVR output change prediction unit 203 acquires the uncompensated voltage 206 from the uncompensated voltage calculation unit 202 and the SVR operation parameter 208 from the SVR operation parameter DB 205, and the SVR output change predicted value 209 when there is no compensation by the SVC 105. Is calculated. In calculating the SVR output change predicted value 209, the SVR output change prediction unit 203 first extracts long-period voltage fluctuations from the uncompensated voltage using a low-pass filter. When long-period voltage fluctuations deviate from the SVR dead band lower limit, it is predicted that the SVR taps up by one step, and when it deviates from the dead band upper limit, the SVR taps down by one step. Predicting and outputting the predicted SVR output change value 209 to the control amount calculation unit 204.

The control amount calculation unit 204 acquires the system information 206 from the system topology DB 201, the SVR output change predicted value 209 from the SVR output change prediction unit 203, and the system voltage from the voltage sensor 106, and calculates the control amount. The control amount is calculated by, for example, Equation 2.

ΔF _SVC is the amount of change in the SVC output, ΔF _SVR is the predicted SVR output change value 209, and K _SVR is the control sensitivity of the _SVR 102, and is uniquely obtained from the system information 206 like the SVC 105.

FIG. 3 is a schematic diagram of the power system 101. The power system 101 is roughly divided into a plurality of nodes 301 and branches 302. The node 301 corresponds to a substation, a pole transformer, a switch, and the like existing on the power system. The branch 302 corresponds to a power line on the power system, and an impedance corresponding to each power line is set. When the nodes 301a to 301g are not particularly distinguished, they are called the node 301, and when the branches 302a to 302e are not particularly distinguished, they are called the branch 302.

For example, node 301a is a substation. Nodes 301b, 301e, and 301g are utility poles to which consumers are connected. The node 301 c is a primary side end of the SVR 102, and the node 301 d is a secondary side end of the SVR 102. The SVC 105 is connected to the node 301f.

FIG. 4 is a flowchart illustrating an example of processing from when the SVC controller 107 acquires the system voltage to when the control amount is calculated.

First, in step S 401, the uncompensated voltage calculation unit 202 acquires the system voltage from the voltage sensor 106.

Next, in step S402, the uncompensated voltage calculation unit 202 acquires the SVC output from the SVC 105 and the system information 206 from the system topology DB 201 in addition to the system voltage, calculates the uncompensated voltage 207, and calculates the SVR output change prediction unit. Output to. As described above, the non-compensation voltage 207 is calculated by, for example, Equation 1, and the control sensitivity is uniquely obtained from the system information 206.

Next, in step S403, the SVR output change prediction unit 203 acquires the non-compensation voltage 207 from the non-compensation voltage calculation unit 202, and extracts long-period fluctuation using, for example, a low-pass filter.

Next, in step S404, the SVR output change prediction unit 203 acquires the SVR operation parameter 208 from the SVR operation parameter DB 205, and determines whether the long-period fluctuation has deviated from the SVR dead zone. If the long-period fluctuation deviates from the SVR dead zone (Yes), the process proceeds to step S405. If not deviating (No), the process proceeds to step S408.

When the process proceeds to step S408, the SVR output change prediction unit 203 sets the SVR output change prediction value 209 to 0 and outputs it to the control amount calculation unit 204.

When the process proceeds to step S405, the SVR output change prediction unit 203 determines whether the long-period fluctuation has deviated from the upper limit or the lower limit of the SVR dead zone. If it deviates from the upper limit (departs from the upper limit), the process proceeds to step S406. If it deviates from the lower limit (departs from the lower limit), the process proceeds to step S407.

When the process proceeds to step S 406, the SVR output change prediction unit 203 calculates the SVR output change predicted value 209 assuming that the SVR performs a step-down operation, and outputs it to the control amount calculation unit 204.

When the process proceeds to step S407, the SVR output change prediction unit 203 calculates the SVR output change predicted value 209, assuming that the SVR performs a boost operation, and outputs it to the control amount calculation unit 204.

Next, in step S409, the control amount calculation unit 204 calculates an SVR output change excluded voltage obtained by excluding the compensation by the SVR output change predicted value 209 from the system voltage. The SVR output change exclusion voltage is calculated by, for example, an expression obtained by multiplying both sides of the above-described expression 2 by K _SVR that is the control sensitivity of the _SVR 102.

Next, in step S410, the control amount calculation unit 204 calculates the SVC control amount from the SVR output change exclusion voltage.

FIG. 5 shows the relationship between the uncompensated voltage 207, long-period fluctuation, voltage compensation due to the predicted SVR output change value 209, and voltage compensation due to SVC. The horizontal axis is time, and the vertical axis is voltage. The uncompensated voltage is indicated by a long dotted line, the long period fluctuation is indicated by a solid line, the voltage compensation by the predicted SVR output change is indicated by a dot area, the voltage compensation by SVC is indicated by a hatching area, and the dead zone is indicated by a short dotted line. The uncompensated voltage is calculated by, for example, Equation 1, and includes both short-period fluctuation and long-period fluctuation. The solid line in the figure shows the long-period fluctuation extracted from the uncompensated voltage. When the long-period fluctuation deviates from the dead zone, the SVR output change predicted value 209 is calculated. The voltage assumed to be compensated by the SVR output change predicted value is the dot area in the figure. Since the SVC compensates the difference between the uncompensated voltage 207 and the voltage compensation by the SVR output change predicted value, the hatched area in the figure is the voltage compensation by the SVC. Hereinafter, consider the voltages at the respective times of t1 before the SVR output change prediction occurs, t2 immediately after the SVR output change prediction occurs, and t3 a short time after the SVR output change prediction, and the outputs of the SVC and SVR. Now, the effect of the invention will be described.

FIG. 6 shows the system voltage at t1 and the outputs of SVR102 and SVC105. The voltage at the SVC installation point is kept constant by the SVC 105 and does not deviate from the dead zone of the SVR. However, the SVC 105 outputs to near the capacity limit.

FIG. 7 shows the system voltage at t2 and the outputs of SVR102 and SVC105. When the long-period component of the non-compensation voltage deviates from the dead zone, the SVC calculates an output change predicted value of the SVR and suppresses the output of the SVC itself. As a result, the system voltage deviates from the upper limit of the SVR dead zone.

FIG. 8 shows the system voltage at t3 and the outputs of SVR102 and SVC105. The SVR performs step-down operation triggered by the fact that the system voltage deviates from the upper limit of the SVR dead band at t2.

As shown in FIGS. 6 to 8 above, in this embodiment, the SVC predicts the output change of the SVR, thereby suppressing the output of the SVC itself. The resulting voltage change induces SVR operation and can share the voltage variation compensated by SVC and SVR. In addition, since the SVC controls the voltage at a constant value except when the output is shifted between the SVC and the SVR, a margin from the upper and lower limits of the system voltage can be secured, thereby contributing to prevention of voltage deviation.

In the second embodiment, a case where the voltage constant point monitored by the SVR is far away from the SVC installation point will be described. In this case, if there is a sensor-equipped switch at a fixed voltage point monitored by the SVR, the voltage at the fixed voltage point can be acquired via the communication line.

FIG. 9 is a functional configuration diagram in the second embodiment. A sensor-equipped switch 901 is connected to the SVC controller 107 via a communication line. The power system 101, the SVR 102, the voltage / current sensor 103, the SVR controller 104, the SVC 105, the voltage sensor 106, the system topology DB 201, and the SVR operation parameter DB 205 in FIG. 9 are the same as those in the first embodiment. The functions of the non-compensation voltage calculation unit 202 and the control amount calculation unit 204 are partially different from those in the first embodiment.

In the second embodiment, the non-compensation voltage calculation unit 202 calculates the non-compensation voltage 901 at a constant voltage monitored by the SVR, not the SVC installation point, and outputs it to the SVR output change prediction unit 203. The control sensitivity of the SVC 105 with respect to a voltage at a fixed voltage monitored by the SVR is uniquely obtained from the system information 206 acquired from the system topology DB 201.

As in the first embodiment, the SVR output change prediction unit 203 extracts long-period fluctuations from the voltage 901 non-compensation voltage 901, determines the deviation of the SVR dead zone, and determines the SVR output change predicted value 209 as the control amount calculation unit 204. To calculate.

When the SVR output change predicted value 209 acquired from the SVR output change prediction unit 203 is non-zero, the control amount calculation unit 204 in the second embodiment controls, for example, an expression so as to control the voltage at a certain voltage point monitored by the SVR. The control amount is calculated according to 3.

V ′ is a voltage at a certain voltage point monitored by the SVR, and K ′ _SVC is a control sensitivity of the SVC with respect to a voltage at the certain voltage point monitored by the SVR.

Further, even when the installation position of the sensor-equipped switch is not the same as the voltage fixed point monitored by the SVR, the voltage at the voltage fixed point can be estimated by load apportionment or linear approximation, so the second embodiment is applied. It is possible.

According to the present embodiment, even when the voltage constant point monitored by the SVR and the SVC installation point are far apart, the SVC can secure a margin of voltage while securing an output capacity and contributes to prevention of voltage deviation.

In the third embodiment, a case where the fixed voltage point monitored by the SVR and the SVC installation point are far away and no communication line exists will be described. In this case, the SVC cannot directly acquire the voltage at the voltage constant point monitored by the SVR. However, it is possible to estimate a voltage change at a fixed voltage point that is indirectly monitored by the SVR.

FIG. 10 is a functional configuration diagram in the third embodiment. The SVR output change prediction unit 203 also acquires the system information 206 from the system topology DB 201.

The non-compensation voltage calculation unit 202 in the third embodiment calculates the difference between the system voltage at the fixed voltage point and the non-compensation voltage 207 from the system voltage at the SVC installation point and the non-compensation voltage 207, that is, the SVC compensation voltage at the voltage fixed point. 1001 is calculated and output to the SVR output change prediction unit 203.

The SVR output change prediction unit 203 in the third embodiment extracts a long-period component of the SVC compensation voltage 1001 at a constant voltage point. When the difference between the maximum value and the minimum value of the extracted long-period components exceeds, for example, the SVR dead band width, an SVR output change predicted value is calculated and output to the control amount calculation unit 204.

When the predicted SVR output change value is non-zero, the control amount calculation unit 204 calculates the control amount according to, for example, Equation 3 so as to control the voltage at the voltage constant point monitored by the SVR.
According to the present embodiment, even when the fixed voltage point monitored by the SVR and the SVC installation point are far apart and there is no communication line, the SVC can secure a margin of voltage while securing an output capacity and voltage deviation. Contributes to prevention.

Embodiment 4 describes a case where the SVR controller 104 and the SVC controller 107 are connected by a communication line.

The non-compensation voltage calculation unit 202 acquires the SVR measurement value 1101 from the SVR controller 104 via the communication line. The SVR measurement value 1101 is a voltage, current, power factor, or the like measured by the voltage / current sensor 103 connected to the SVR controller 104.

The non-compensation voltage calculation unit 202 represents the non-compensation voltage 901 at a fixed voltage point monitored by the SVR based on the acquired SVR measurement value 1101, the system information 206, the output of the SVC 105, and the SVR operation parameter 208, for example, as shown in Equation 4. Estimated by LDC (Line Drop Compensator).

V ₀ ′ is the uncompensated voltage at the fixed voltage point monitored by the SVR, R is the resistance from the SVR to the fixed voltage point, X is the reactance from the SVR to the fixed voltage point, and I ₀ is on the secondary side of the SVR The current when no SVC is compensated, θ is the power factor on the secondary side of the SVR.

When the SVR output change prediction value calculated by the SVR output change prediction unit is non-zero, the SVR output change prediction value is transmitted to the SVR controller via the communication line. In the case where the SVR operates in response to an external command, the SVC cooperates with the SVR according to the present embodiment, and can ensure a voltage margin while ensuring an output remaining capacity, thereby contributing to prevention of voltage deviation.

101 Power system 102 SVR
103 Voltage Current Sensor 104 SVR Controller 105 SVC
106 Voltage sensor 107 SVC controller 201 System topology DB
202 Non-compensation voltage calculation unit 203 SVR output change prediction unit 204 Control amount calculation unit 205 SVR operation parameter DB
206 System information 207 Non-compensation voltage 208 SVR operation parameter 209 SVR output change predicted value 301 Node 302 Branch 303 Load 901 Voltage fixed point non-compensation voltage 1001 SVC compensation voltage 1101 SVR measured value 1102 Operation command

Claims (14)

A voltage control device for controlling the voltage of a power system,
A non-compensation voltage calculation unit that calculates a non-compensation voltage that is a system voltage when the voltage control device is uncompensated based on the system information of the power system, the system voltage, and the output of the voltage control device;
Based on the system information, the non-compensation voltage, and the other voltage control device operation parameter that is the operation parameter of the other voltage control device in the power system, the output of the other voltage control device when the voltage control device is not compensated Other voltage control device output change prediction unit for predicting the change amount,
A control amount calculation unit that calculates a control amount of the voltage control device from the system information, the system voltage, and an output change prediction amount of the other voltage control device;
A voltage control device comprising: The voltage control device according to claim 1 is:
Another voltage control device operation parameter DB for storing operation parameters of the other voltage control device;
A system information DB for storing system information;
The voltage control apparatus further comprising: The voltage control device according to claim 1,
Indirectly controlling the voltage by changing the power flow in the power system,
A voltage control device. The voltage control device according to claim 1,
The other voltage control device operation parameter is a parameter that is used by the other voltage control device to calculate a control amount or determine an operation, and is set statically or dynamically in advance.
A voltage control device. The voltage control device according to claim 1,
The grid information includes the impedance of the branch in the power system, the connection status of the branch, the arrangement of the equipment,
A voltage control device. The voltage control device according to claim 1,
The non-compensation voltage calculation unit calculates the control sensitivity of the voltage control device with respect to the voltage at a predetermined point on the power system from the system information;
A voltage control device. The voltage control device according to claim 1,
The uncompensated voltage calculation unit subtracts the product of the output of the voltage control device and the control sensitivity of the voltage control device from the system voltage,
A voltage control device. The voltage control device according to claim 1,
The other voltage control device output change prediction unit extracts long-period fluctuations from the non-compensation voltage,
A voltage control device. The voltage control device according to claim 1,
The other voltage control device output change predicting unit outputs the output of the other voltage control device when the long period variation exists on the power system by comparing the long cycle variation and the other voltage control device operation parameter. To determine if it changes,
A voltage control device. The voltage control device according to claim 1,
When the other voltage control device output change prediction unit determines that the output of the other voltage control device changes, the output change amount of the other voltage control device is calculated.
A voltage control device. The voltage control device according to claim 1 is:
An output change amount of the other voltage control device further comprising a transmission unit that transmits the other voltage control device to the other voltage control device via a communication line;
A voltage control device. The voltage control device according to claim 1,
The control amount calculation unit calculates a control sensitivity of the other voltage control device with respect to a voltage at a predetermined point on the power system from the system information;
A voltage control device. The voltage control device according to claim 1,
The control amount calculation unit subtracts the product of the output change amount of the other voltage control device and the control sensitivity of the other voltage control device from the system voltage, and divides by the control sensitivity of the voltage control device;
A voltage control device. A control method of a voltage control device for controlling the voltage of an electric power system,
Based on the system information of the power system, the system voltage, and the output of the voltage control device, the voltage control device calculates a non-compensation voltage that is a system voltage at the time of no compensation,
Based on the system information, the non-compensation voltage, and the other voltage control device operation parameter that is an operation parameter of the other voltage control device in the power system, the output change of the other voltage control device when the voltage control device is not compensated Predict the quantity,
Calculating a control amount of the voltage control device from the system information, the system voltage, and an output change prediction amount of the other voltage control device;
A control method for a voltage control device.

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