JP5457949B2 - Reactive power compensator with power flow calculation function, and system and method thereof - Google Patents

Description

  The present invention relates to a reactive power compensator that compensates for voltage fluctuations in a distribution system, and a system and method thereof.

In the distribution system (power system), it is important to stabilize the voltage of the distribution line without being affected by load fluctuations. For this reason, conventionally, an automatic voltage regulator connected to a necessary part of a distribution line by adjusting a supply voltage by a load switching device (LRT tap: Load Ratio control Transfomer, hereinafter abbreviated as LRT) of a distribution substation. A voltage regulator such as SVR (Step Voltage Regulator, hereinafter also referred to as SVR) is used to stabilize the voltage of the distribution line.
When the power flow is unidirectional from the upper system to the lower system, the voltage of the distribution system is controlled so that the customer voltage is maintained within a certain range by installing a voltage regulator on this assumption.

However, in recent years, clean natural energy power generation and highly efficient cogeneration systems have attracted attention due to problems such as global warming and fossil fuel depletion, and power sources such as wind power generation and solar power generation that make this possible Increasingly, it has been installed as a distributed power source near consumers.
When the distributed power source increases, not only power flows from the upper system to the lower system, but also a reverse power flow from the distributed power source connected to the lower system to the upper system may occur. Voltage fluctuations need to be taken into account even by distributed power output that fluctuates due to weather such as solar power generation.

In recent years, a reactive power compensation system (SVC: Static Var Compensator) using a reactive power compensator can be used because a voltage regulator such as SVR cannot follow a load fluctuation or a voltage fluctuation caused by a distributed power output. It is considered to apply.
Voltage regulators such as LRT and SVR of distribution substations are applied to such mild load fluctuations, and reactive power compensation devices are applied to sudden load fluctuations to stabilize the voltage on distribution lines. Control is planned.
Patent Documents 1 to 3 disclose techniques for reactive power compensation devices, reactive power compensation methods, and systems.
Moreover, in patent document 4, the state estimation apparatus of a distribution system, the state estimation method, and the technique of the program are disclosed.

JP-A-11-155236 JP 2001-28835 A JP 2001-51734 A JP 2008-154418 A

However, the installation of distributed power sources such as wind power generation and solar power generation is increasing, and the response by the above-described LRT and SVR is becoming insufficient.
Also, in the reactive power compensator installed to cope with them, the reactive power compensator, system and method disclosed in Patent Documents 1 to 4 control the reactive power compensator according to the voltage command reference value. Even if the voltage at the installation point can be maintained, the customer voltage may deviate from a certain range at different points on the same distribution line.

  Accordingly, the present invention solves such problems, and an object of the present invention is to provide a reactive power compensator in which the entire distribution system maintains a voltage within an appropriate fixed range, and a system and method thereof. Is to provide.

In order to solve the above-described problems and achieve the object of the present invention, the present invention is configured as follows.
That is, a reactive power compensator that stabilizes the voltage of the distribution system by controlling the reactive power injected into the distribution system based on the voltage command reference value and the measurement information of the distribution system. A voltage command correction circuit having a power flow calculation function based on a line model is provided, and measurement information of a distribution system at a point different from the installation point of the reactive power compensator is input to the voltage command correction circuit, and the measurement information of the distribution system On the basis of the power flow calculation, the voltage command reference value is corrected with the output of the voltage command correction amount of the voltage command correction circuit so that the voltage of the entire distribution system is within a certain range.

  With this configuration, the power flow of the distribution line can be calculated based on the measurement information of a plurality of different points in the distribution system, the voltage of the entire distribution system can be estimated, and the voltage command reference value is corrected with the voltage command amount based on it. The reactive power compensator injects reactive power into the distribution system, and the voltage of the entire system is maintained within a certain range.

  According to the present invention, it is possible to provide a reactive power compensator in which the entire power distribution system maintains a voltage within an appropriate fixed range, and a system and method thereof.

It is a block diagram which shows the relationship between the reactive power compensation apparatus and distribution system of embodiment of this invention. It is a flowchart which shows the method of calculating the correction amount to the voltage instruction | command reference value in embodiment of this invention. It is a figure which shows the 1st voltage characteristic of a power distribution system for demonstrating operation | movement of the voltage command correction circuit in embodiment of this invention. It is a figure which shows the 2nd voltage characteristic of a power distribution system for demonstrating operation | movement of the voltage command correction circuit in embodiment of this invention. It is a figure which shows the 3rd voltage characteristic of a power distribution system for demonstrating operation | movement of the voltage command correction circuit in embodiment of this invention. FIG. 5 is a reference diagram illustrating a configuration related to a reactive power compensator and a distribution system as a comparative example.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a configuration diagram showing a relationship between a power distribution system (power system) and an embodiment of a reactive power compensator having a power flow calculation function of the present invention. In the following description, the reactive power compensation system having a power flow calculation function is also described.
In the distribution system in FIG. 1, power is supplied to each load 5 from the distribution substation 1 through the distribution line 2. Furthermore, the C ₁ point is a terminal of a power distribution system is the output of the reactive power compensator 31 is connected (also referred to SVR voltage regulator) voltage regulator is SVR is halfway 3 is connected. Moreover, the switch 4 is provided in the location used as a branch load between this terminal.
As means for stabilizing the voltage of the distribution system, adjustment of the sending voltage by LRT (not shown) of the distribution substation 1, adjustment by tap control of the SVR voltage regulator 3 (voltage regulator 3), reactive power compensation device There is a voltage control by 31.

The adjustment of the delivery voltage by LRT (not shown) and the adjustment by tap control of the SVR voltage regulator 3 are adjustments paying attention to the original voltage of AC power itself, but the reactive power compensator 31 supplies reactive power. This is an adjustment method that optimizes the voltage by (compensating) and matching (improving) the phase of AC power (the phase relationship between voltage and current).
The reactive power compensation by the reactive power compensation device 31 is performed based on a voltage command correction amount that is an output from the voltage command correction circuit 21.

The combination of the reactive power compensator 31 and the voltage command correction circuit 21 is a “reactive power compensator having a power flow calculation function” which is one embodiment of the present invention.
Further, the reactive power compensator 31 can be regarded as reactive power compensation means, and the voltage command correction circuit 21 can be regarded as voltage command correction means. At this time, a combination of the reactive power compensation means and the voltage command correction means is a “reactive power compensation system having a power flow calculation function” which is one embodiment of the present invention.
Next, the reactive power compensator 31 and the voltage command correction circuit 21 will be described in order.

<Reactive power compensator and means>
The configuration of the reactive power compensator will be described with reference to FIG. It also serves as a description of reactive power compensation means.
In FIG. 1, the reactive power compensator 31 surrounded by an alternate long and short dash line 31 includes a conversion device 9, a voltage detection circuit 10, a PWM (Pulse Width Modulation) control circuit 11, a current control circuit 12, a voltage control circuit 13, and a voltage command reference value. 14, a computing unit 15 and a computing unit 16.
Voltage detecting circuit 10 detects a voltage converted voltage of C ₂ points of the distribution system in instrument transformer 6. The detected voltage value is transmitted to the voltage command correction circuit 21.
Voltage command reference value 14, instructs the target voltage at the C ₂ points of the distribution system as a reference value, and outputs.

The arithmetic unit 16 performs an operation of adding the voltage command correction amount that is an output from the voltage command correction circuit 21 and the voltage command reference value that is an output of the voltage command reference value 14.
The arithmetic unit 15 performs an operation of subtracting the voltage value detected by the voltage detection circuit 10 from the output value of the arithmetic unit 16.
The voltage control circuit 13 outputs a signal to the current control circuit 12 based on the output value calculated by the calculator 15.
The current control circuit 12, based on the current value detected output signal, the current transformer 7 the current flowing in the C ₁ point of the distribution system from the converter 9 of the voltage control circuit 13, the PWM control circuit 11 Output a signal.
The PWM control circuit 11 forms a pulse width control signal (PWM signal) for controlling the conversion device 9 based on the output value relating to the current value of the current control circuit 12 and outputs the pulse width control signal to the conversion device 9.

The conversion device 9 includes a plurality of switching elements (IGBT (Insulated Gate Bipolar Transistor), etc.) (not shown) and a large-capacitance capacitor (power capacity and capacitance are large, the power capacity is approximately several hundred KVA or more) (not shown). the equipped, while being controlled in the PWM control circuit 11 described above, output the C ₁ point of the distribution system is connected. Converter 9 by being controlled by the control signal of the PWM control circuit 11, on the electrical interaction between the distribution system in the capacitor with C ₁ point of the mass. At this time, by the action of the capacitor of the high-capacity, reactive power equivalently occur in C ₁ point of the distribution system, the reactive power is compensated, the voltage recovers (rises).

Since the generation of reactive power due to the action of the large-capacity capacitor is variable by the control signal of the PWM control circuit 11, the voltage command correction amount of the voltage command correction circuit 21, the voltage command reference value 14, and the instrument transformation the voltage value of C ₂ points of the distribution system by vessel 6, to reflect the current value flowing to the C ₁ point of the detected power distribution system by the current transformer 7, a C ₁ point of the distribution system if properly controlled The voltage is compensated to the desired value.
Note that the C ₁ point and C ₂ points of the distribution system, are substantially the same point, also referred to as C point.

<Voltage command correction circuit / means>
Next, the configuration of the voltage command correction circuit 21 will be described. It also serves as a description of the voltage command correction means.
The voltage command correction circuit 21 is connected to the reactive power compensator 31 so that the voltage command correction amount as its output is related to the control of the reactive power compensator 31 described above.
The voltage command correction circuit 21 includes a program data 22, a power flow calculation / voltage estimation calculation database 23, a power flow calculation circuit 24, a CPU (Central Processing Unit) 25 that performs arithmetic processing, a RAM (Random Access Memory) 26 as a calculation memory, The communication means 27 for taking in the measurement information of the point and the settling display circuit 28 for performing the setting operation and display are provided.

The program data 22 includes a power flow calculation program and a voltage estimation calculation program.
The power flow calculation / voltage estimation calculation database 23 is provided with information such as a line impedance constant (line constant Z), a load amount, a power generation amount, and a system configuration.
Further, the power flow calculation circuit 24 has functions of power flow calculation, voltage estimation calculation, and optimum reference voltage calculation.

As described above, information such as line impedance constant, load amount, power generation amount, system (distribution system) configuration, etc., which becomes the power flow calculation, voltage estimation calculation database 23, is input to the voltage command correction circuit 21 in advance, and representative measurement points Using the measured information, the power flow calculation circuit 24 can perform the power flow calculation and the voltage estimation calculation of each node of the entire system set in advance.
These are referred to as “tidal current calculation by distribution line model” or “tidal current calculation function by distribution line model”. Further, the “distribution line model” may be referred to as a “distribution line model”. Therefore, it may be expressed as “tidal flow calculation by distribution line model”.
Further, reference numeral 2 in the distribution line 2 may represent the line impedance 2.
Further, the communication means 27, the settling display circuit 28, the RAM 26, and the CPU 25 are utilized in the process of taking in the above measurement information and the calculation process.

<Selection of measurement information>
Next, selection of measurement information of the distribution system will be described. In Figure 1, C point is established end of the reactive power compensator (C ₁ point, C ₂ points) to another, the voltage to point B corresponding to the intermediate point A and the distribution line of the neighboring distribution substation, to measure the current The sensor 8 is connected, and the switch state of the switch 4 having a branch system, the tap value of the SVR voltage regulator 3 and the like are input to the voltage command correction circuit 21 via the communication means 27 as measurement information. Yes.
Here, in estimating the voltage of the entire distribution system, the sensor 8 for measuring the voltage and current is set to at least two locations, and the locations near the distribution substation and the end are selected as much as possible, and the sensor 8 is installed. By doing so, the voltage of the entire power distribution system can be estimated.

When there is a relatively large branch load in the target distribution system, the presence or absence of the branch load can be reflected in the power flow calculation by inputting the switch state of the branch point. When the SVR voltage regulator 3 or the like is connected, it is possible to estimate the voltage including the transformation ratio by inputting the tap value.
In addition, since the selection of these measurement information is different for each target distribution system, it is possible to set the measurement information to be input together with the distribution system data by using the settling display circuit 28 or the like so that different distribution systems can be set. It can also be applied to systems.

In addition, according to the configuration of FIG. 1, the measurement information at different points in the distribution system includes the voltage and current at point A, the voltage and current at point B, the switching state of the switch 4 serving as a branch system, and the distribution substation. The tap value of the SVR voltage regulator 3 installed between the point 1 and the point C that is the connection point of the reactive power compensator 31 is shown.
In order to improve the accuracy of the tidal current calculation, it is better to increase the measurement information, but there is a problem that the cost related to the installation of the sensor 8 and the communication is increased, and the number of measurement points is small. It is desirable to select measurement points that can grasp the power flow of the entire distribution system.
In FIG. 1, taking into account this cost, the point A close to the distribution substation 1, the point C as the installation point of the reactive power compensator 31 which is the end of the system, and the point B in the middle of the system are measured. By selecting a point, a configuration is selected that allows tidal current calculations over the entire system at low cost.

<Voltage command reference value correction method>
Next, an example of a method for correcting the voltage command reference value will be described.
The flowchart of FIG. 2 is an example of a method for calculating the correction amount of the voltage command reference value.
First, in step S31, measurement values are collected at each point.
Next, in step S32, power flow calculation is performed using the distribution system data input in advance and the measurement information.
Next, in step S33, a voltage state estimation calculation at each node of the target distribution system is performed.

Next, in step S34, the calculation result in step S33 is compared with a preset voltage upper limit value to determine whether or not there is a deviation point at the voltage upper limit.
If there is a departure point at the upper voltage limit (Yes), the process proceeds to step S35Y.
If there is no departure point at the upper voltage limit (No), the process proceeds to step S35N.

First, in the case of proceeding to step S35Y (when there is a deviation point at the upper limit in step S34 (Yes)), the calculation result in step S33 is compared with the preset voltage lower limit value, It is determined whether there is a deviation point at the lower voltage limit.
If there is no departure point at the lower voltage limit (No), the process proceeds to step S36.
If there is a departure point at the lower voltage limit (Yes), the process proceeds to step S37.

  First, when the process proceeds to step S36 (when there is no departure point at the lower limit in step S35Y (No)), the calculation result at step S33 is only the departure point at the upper limit and there is no departure point at the lower limit. Therefore, the voltage command correction amount is calculated so that the voltage command correction amount is in the downward direction.

  Further, when the process proceeds to step S37 (when there is a deviation point at the lower limit in step S35Y (Yes)), this corresponds to the case where the calculation result in step S33 has both an upper limit and a deviation point at the lower limit. Therefore, the correction is not performed because it is determined that the correction is not appropriate in both the upward and downward directions. Therefore, the voltage command correction amount is set to zero.

If No in step S34 and the process proceeds to step S35N, the calculation result in step S33 is compared with a preset voltage lower limit value to determine whether there is a deviation point at the lower limit. Determine.
If there is a departure point at the lower voltage limit (Yes), the process proceeds to step S38.
If there is no departure point at the lower voltage limit (No), the process proceeds to step S39.

  First, when the process proceeds to step S38 (when there is a deviation point at the lower limit in step S35N (Yes)), the calculation result at step S33 is only the deviation point at the lower limit and there is no deviation point at the upper limit. Therefore, the voltage command correction amount is calculated so that the voltage command correction amount increases.

  Further, when the process proceeds to step S39 (when there is no departure point at the lower limit in step S35N (No)), the calculation result at step S33 corresponds to the case where there is no departure point at the upper limit and the lower limit. Since it is already within the appropriate range, it is determined that no correction is necessary in both the upward and downward directions, and no correction is made. Therefore, the voltage command correction amount is set to zero.

  In each of steps S36 to S39, after the voltage command correction amount is determined and output, the process returns to step S31, and after a predetermined time has elapsed, the process is started again from step S31 and repeated.

The flowchart of FIG. 2 is as described above.
In this way, by appropriately setting the voltage upper limit value and voltage lower limit value for enabling the voltage command correction function, the correction function is added when necessary according to the state change of the system. Yes.
In addition, the correction of the voltage command usually does not require a steep response. Therefore, when the correction amount is slowly added to the reference voltage command value, a first-order delay occurs in the correction amount output unit of the voltage command correction circuit. It is effective to install a circuit.
In order to make it easy to understand the determination method performed in the above flow chart, several voltage characteristic examples of the distribution system will be described below.

<First voltage characteristic in power distribution system>
FIG. 3 shows the first voltage characteristic in the distribution system, and also shows an example of the voltage characteristic of a general distribution system. The vertical axis indicates the voltage value, and the horizontal axis indicates the distance from the distribution substation.
In the voltage characteristics in the distribution system of FIG. 3, it can be seen that the voltage values from point A to point B and point C are within the appropriate voltage range.
The change point between the points A and B indicates that the voltage after the secondary side is in the increasing direction due to the transformation ratio of the SVR voltage regulator 3.

<Second voltage characteristic in power distribution system>
Next, FIG. 4 shows a second voltage characteristic in the distribution system. FIG. 4 shows the voltage characteristics of the distribution system as in FIG. 3, and the vertical and horizontal axes are the same as those in FIG.
Although the voltage at the point C in FIG. 4 is the same as that in FIG. 3, the voltages at the points A and B are higher than those in FIG. 3 (two-dot chain line portion in FIG. 4). It can be seen that the appropriate voltage is deviated near the vessel (voltage deviation point 401).

In the reactive power compensator with insufficient voltage measurement information in the distribution system (FIG. 6), the voltage at the point C, which is the installation point, is controlled according to the voltage command reference value, and near the SVR voltage regulator (voltage deviation point). Since the voltage deviation at 401) cannot be recognized, the voltage control of the reactive power compensator is maintained in the state of FIG.
Such voltage fluctuation is a phenomenon in which the system voltage rises locally due to the reverse power flow caused by distributed power sources such as wind power generation and solar power generation, which have been increasing in recent years. This is a concern.

<Third voltage characteristic in power distribution system>
Next, FIG. 5 shows a third voltage characteristic in the power distribution system. FIG. 5 shows the result of optimally correcting the voltage command reference value 14 (FIG. 1) by providing the above-described voltage command correction circuit 21 (FIG. 1) in the reactive power compensator 31 (FIG. 1). Is.
As a result of calculating the power flow of the entire distribution system from the measurement information of the points A and B and the tap value of the SVR voltage regulator 3 (FIG. 1), in the vicinity of the SVR voltage regulator (voltage deviation point 401 (FIG. 4)). The result of recognizing that the voltage deviated from the upper limit value and controlling the voltage command reference value 14 (FIG. 1) of the reactive power compensator 31 (FIG. 1) by adding a correction in the voltage decreasing direction is shown.

In FIG. 5, it is understood that the voltage near the SVR voltage regulator that has deviated in FIG. 4 is within the appropriate range by correcting the voltage command reference at point C to the lower side.
Thus, in the reactive power compensator of the present invention, there is an effect that optimum voltage control can be performed in consideration of the voltage of the entire system by using measurement information at a point different from the installation point of the reactive power compensator.

<When voltage command reference value fluctuates frequently>
According to the embodiment shown in FIG. 1 and the voltage command correction amount calculation shown in FIG. 2, an optimum voltage command reference value can be obtained, but on the other hand, when the voltage command reference value 14 frequently fluctuates. The impact on the system must also be considered. For example, measurement information from different points (A point, B point, C point, switch 4, voltage regulator 3) of the distribution system is input via the communication means 27. It is not always the measurement information. If these measurement information is used to frequently correct the voltage command reference value 14, it may interfere with the output fluctuation of the reactive power compensator 31 and adversely affect the system.

  On the other hand, for the purpose of keeping the voltage of the entire distribution system within a certain range, the correction of the voltage command reference value 14 only needs to function when the voltage deviates from the certain range. There is no need to change to. Therefore, by giving these various conditions to the voltage command correction circuit 21, the voltage command correction amount can be set only when necessary with respect to a certain voltage command reference value 14 with a conventional fixed value or a semi-fixed value such as time schedule switching. By adding the above, the influence on the system due to the above-described interference can be prevented.

<Comparative example>
FIG. 6 is a reference diagram showing a configuration related to a reactive power compensator (reactive power compensation system) and a distribution system as a comparative example.
As shown in FIG. 6, this reactive power compensator (reactive power compensation system) connects the converter 9 in the reactive power compensator to the distribution line 2, and sets the distribution line voltage at the point C as a voltage command. Reactive power compensation is performed so that the reference value 14 is obtained. The calculator 15 of this reactive power compensator compares the voltage at the point C, which is a connection point detected by the instrument transformer 6 and the voltage detection circuit 10, with the voltage command reference value 14, and a deviation corresponding to the difference. A value is input to the voltage control circuit 13 to calculate a reactive power compensation amount based on the deviation value. This required reactive power compensation amount is configured to be provided to the reactive power compensator (corresponding to the circuit in the one-dot chain line 31 in FIG. 1) via the current control circuit 12 and the PWM circuit 11.

  However, in the situation where a large number of distributed power sources have been introduced, if the customer voltage of the entire distribution line is to be kept within a certain range, the voltage at the installation point of the voltage regulator is in line with the command value. Even so, the consumer voltage at different points in the distribution system may exceed a certain range.

(Other embodiments)
In the above, there is a power flow calculation function based on the distribution line model of the distribution system, and the present invention has been described from the viewpoint of the apparatus as a reactive power compensator having a voltage command correction circuit mainly having the function. The present invention is also useful as a reactive power compensation system including voltage command correcting means having the function.

  Moreover, the point of measurement information is not limited to the part shown in FIG. There may be more distribution system points or fewer points. Moreover, although there exist the switch state of the switch 4 and the tap value of the voltage regulator 3 as measurement information, when other apparatuses are used, the measurement information may be used.

  Moreover, although the power flow calculation program and the voltage estimation calculation program are exemplified as the program data 22 constituting the voltage command correction circuit 21, there may be cases where other programs are provided, which may be useful.

  Further, as the tidal current calculation / voltage estimation calculation database 23 constituting the voltage command correction circuit 21, the power line calculation program and the voltage estimation calculation program are exemplified as the line constant Z, the load amount, the power generation amount, and the system configuration. May be useful.

  In addition, the power flow calculation circuit 24 constituting the voltage command correction circuit 21 is exemplified by the functions of power flow calculation, voltage estimation calculation, and optimum reference voltage calculation. However, other functions may be provided and may be useful. .

  Further, although the RAM 26, the CPU 25, the communication means 27, and the circuit and means of the settling display circuit 28 are illustrated as elements constituting the voltage command correction circuit 21, other elements may be provided as necessary, which is useful. Sometimes.

  In addition, as elements constituting the reactive power compensator 31, the converter 9, the voltage detection circuit 10, the PWM control circuit 11, the current control circuit 12, the voltage control circuit 13, the voltage command reference value 14, the calculator 15, and the calculator 16 Although the circuit and the device have been exemplified, other circuits and devices may be provided as necessary, which may be useful. Further, the current transformer 7 or the instrument transformer 6 may be included as an element constituting the reactive power compensator 31.

  Further, in the flowchart of the method for correcting the voltage command reference value 14 in FIG. 2, in determining whether or not there is a voltage departure point, “There is a voltage upper departure point? (S34)” and “Voltage lower limit departure point? , (S35N) ”, the determination may be made by reversing the order of the upper limit and the lower limit.

  Further, in the flowchart of the method for correcting the voltage command reference value 14 in FIG. 2, in step S37, since both the upper and lower limits of the voltage are deviated, the correction cannot be made and “voltage command correction amount 0” is set. Comparing the deviation amount at the upper limit of the voltage with the deviation amount at the lower limit of the voltage may be performed so that the deviation is further reduced.

  Further, in the flowchart of the method for correcting the voltage command reference value 14 of FIG. 2, in step S39, since both the upper limit and the lower limit of the voltage are not deviated, they are within the appropriate voltage range and no correction is necessary. Although the “command correction amount is 0”, a value close to the upper limit of the voltage and a value close to the lower limit of the voltage may be compared to perform correction that reduces the risk of deviation.

As described above, according to the present invention, when the reactive power injected into the distribution line is controlled based on the voltage fluctuation of the distribution line, not only the installation point of the reactive power compensator but also a plurality of distribution systems. Based on the measurement information at different points, the power flow of the distribution line is calculated to compensate for the optimum reactive power to keep the voltage of the entire system within a certain range.
As described above, the reactive power compensator of the present invention has an effect that optimum voltage control can be performed in consideration of the voltage of the entire system by using measurement information at a point different from the installation point of the reactive power compensator.

DESCRIPTION OF SYMBOLS 1 Distribution substation 2 Distribution line, Line impedance 3 SVR voltage regulator, voltage regulator 4 Switch 5 Load 6 Instrument transformer 7 Instrument current transformer 8 Sensor 9 Converter 10 Voltage detection circuit 11 PWM control circuit 12 Current Control circuit 13 Voltage control circuit 14 Voltage command reference value 15, 16 Calculator 21 Voltage command correction circuit, voltage command correction means 22 Program data 23 Power flow calculation / voltage estimation calculation database 24 Power flow calculation circuit 25 CPU
26 RAM
27 communication means 28 settling display circuit 31 reactive power compensator, reactive power compensation means 401 voltage deviation point

Claims (3)

A reactive power compensator that stabilizes the voltage of the distribution system by controlling the reactive power injected into the distribution system based on the voltage command reference value and the measurement information of the distribution system,
further,
Equipped with a voltage command correction circuit with a power flow calculation function based on a distribution line model of the distribution system,
The measurement information of the distribution system at a point different from the installation point of the reactive power compensator is input to the voltage command correction circuit, the power flow calculation is performed based on the measurement information of the distribution system, and the voltage of the entire distribution system is within a certain range. A reactive power compensator having a power flow calculation function, wherein the voltage command reference value is corrected by the output of the voltage command correction amount of the voltage command correction circuit so that A reactive power compensation system including reactive power compensation means for stabilizing the voltage of the distribution system by controlling the reactive power injected into the distribution system based on the voltage command reference value and the measurement information of the distribution system,
further,
Equipped with voltage command correction means with power flow calculation function by distribution line model of distribution system,
The measurement information of the distribution system at a point different from the installation point of the reactive power compensation unit is input to the voltage command correction unit, the power flow calculation is performed based on the measurement information of the distribution system, and the voltage of the entire distribution system is within a certain range. A reactive power compensation system having a power flow calculation function, wherein the voltage command reference value is corrected with the output of the voltage command correction amount of the voltage command correction means. A reactive power compensation method for a reactive power compensation system comprising reactive power compensation means for stabilizing the voltage of a distribution system by controlling the reactive power injected into the distribution system based on the voltage command reference value and the measurement information of the distribution system. There,
further,
The reactive power compensation system includes voltage command correction means having a power flow calculation function based on a distribution line model of a distribution system,
The measurement information of the distribution system at a point different from the installation point of the reactive power compensation unit is input to the voltage command correction unit, the power flow calculation is performed based on the measurement information of the distribution system, and the voltage of the entire distribution system is within a certain range. A reactive power compensation method having a power flow calculation function, wherein the voltage command reference value is corrected by the output of the voltage command correction amount of the voltage command correction means.

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