JP2023023975A - Voltage control device, voltage control method, and voltage control system - Google Patents

Abstract

To provide a voltage control device that does not require a new SVR to be added even when a distribution line voltage estimated in a set point setting method deviates from an allowable range.SOLUTION: The voltage control device includes: a data input unit 31 into which data related to power consumption of a distribution system and a load is input; a set point value calculation unit 32 for calculating a set point value in a set point value setting method on the basis of the data inputted into the data input unit; a control method determining unit 33 for calculating a voltage value of a power distribution line on the basis of the set point value calculated by the set point value calculation unit and determining whether the calculated voltage value satisfies a voltage condition of the distribution system; and a control method change command unit 34 for commanding a control method to be changed from the set point value setting method to a tap direct control method on the basis of a determination of the control method determining unit.SELECTED DRAWING: Figure 2

Description

The present application relates to a voltage control device, a voltage control method, and a voltage control system.

The voltage of the distribution system is controlled by a load ratio control transformer (hereinafter referred to as LRT) installed at the distribution substation and an automatic voltage regulator (hereinafter referred to as SVR) installed on the distribution line. described). In recent years, distribution lines have not only power-consuming loads such as factories, general houses, and quick chargers for electric vehicles, but also power-supplying loads such as power sources that use renewable energy such as storage batteries and solar power generation. It is connected. Therefore, voltage fluctuations in the distribution line increase, and the voltage in the distribution line may greatly deviate from the rated voltage.

LRTs, SVRs have Line Drop Compensators (LDCs) combined with taps to compensate for voltage drops in the distribution system. This LDC has resistive and reactive components that are matching elements of the line impedance from the SVR to the load center. In the LDC, the resistance value of the resistor and the reactance value of the reactance component are set so that the voltage at the center point of the load is constant. The resistance value and reactance value of this LDC are called set values. Therefore, this LDC voltage control method is also called a set value setting method.

In the setting value setting method, an appropriate setting value is set so that the voltage of the distribution line does not deviate from the allowable range of the rated voltage. For example, as a voltage control method using the conventional setting value setting method, actual measurement data is collected from measuring instruments installed on the distribution line, power flow is calculated during a preset operation period based on this measurement data, and the distribution line and calculating a set value so that the estimated voltage falls within an allowable range. Then, if the voltage estimated by the already calculated set value is within the allowable range in the next operation period as well, the operation period is extended (see, for example, Patent Literature 1).

JP 2017-70025 A

However, in the conventional voltage control method, there is a problem that even when an attempt is made to appropriately set the setpoint, it is not possible to cope with cases where the estimated voltage deviates from the allowable voltage range of the distribution line. Therefore, in the conventional voltage control device, when the voltage of the distribution line estimated by the set value setting method deviates from the allowable range, it is necessary to add a new SVR.

The present application has been made to solve the above-mentioned problems, and provides a voltage control device that does not require a new SVR even when the voltage of the distribution line estimated by the setting value setting method deviates from the allowable range. intended to provide

The voltage control device of the present application includes a data input unit for inputting data related to the power consumption of loads connected to the distribution system and the distribution line, and a setting value setting method based on the data input to the data input unit. A setting value calculation unit that calculates a value, a voltage value of the distribution line is calculated based on the setting value calculated by the setting value calculation unit, and whether or not the calculated voltage value satisfies the voltage conditions of the distribution system is checked. and a control method change command unit for instructing the control method to be changed from the set value setting method to the tap direct control method based on the determination by the control method determination unit.

A voltage control device of the present application includes a control method determination unit that calculates a voltage value of a distribution line based on a set value and determines whether the calculated voltage value satisfies a voltage condition of a distribution system; and a control method change command unit that commands to change the control method from the set value setting method to the tap direct control method based on the judgment of the unit, so that the voltage of the distribution line estimated by the set value setting method is If the allowable range is exceeded, the control method can be changed from the setting value setting method to the tap direct control method. Therefore, in the voltage control device of the present application, even when the voltage of the distribution line estimated by the set value setting method deviates from the allowable range, it is not necessary to add a new SVR.

1 is a schematic diagram of a voltage control system according to Embodiment 1; FIG. 1 is a schematic diagram of a voltage control device according to Embodiment 1; FIG. 4 is an explanatory diagram of a setting value setting method according to the first embodiment; FIG. FIG. 2 is an explanatory diagram of a tap direct control method according to Embodiment 1; FIG. 4 is a flowchart of a voltage control method according to Embodiment 1; FIG. 5 is an explanatory diagram showing a calculation example in a control method determination unit according to Embodiment 1; 10 is a flowchart of a voltage control method according to Embodiment 2; FIG. 10 is a schematic diagram of a voltage control device according to Embodiment 3; FIG. 3 is a schematic diagram showing an example of hardware of the voltage control device according to Embodiments 1 to 3; FIG.

A voltage control device and a voltage control system according to embodiments for carrying out the present application will be described in detail below with reference to the drawings. In each figure, the same reference numerals denote the same or corresponding parts.

Embodiment 1.
FIG. 1 is a schematic diagram of a voltage control system according to Embodiment 1. FIG. As shown in FIG. 1, a voltage control system 10 of the present embodiment includes a plurality of SVRs 2 installed in distribution lines 1 of a distribution system and a voltage control device 3 that controls the SVRs 2 . Electric power is sent to the distribution line 1 from an LRT 4 provided at a distribution substation. The target voltage of the distribution system is set to 6600V, for example. SVR2 has an LDC associated with the tap. A plurality of loads 5 are connected to the distribution line 1 . The plurality of loads 5 includes not only loads that consume power but also loads that supply power. Power-consuming loads include, for example, factories, general residences, and quick chargers for electric vehicles. The loads to which electric power is supplied include, for example, storage batteries, power sources using renewable energy such as solar power generation, and the like. In addition, a plurality of sensor-embedded switches 6 are installed on the distribution line 1 . The sensor built-in switch 6 transmits the voltage of the distribution line 1 at the installed position to the voltage control device 3 .

FIG. 2 is a schematic diagram of the voltage control device 3 according to this embodiment. As shown in FIG. 2, the voltage control device 3 of the present embodiment has a data input section 31, a set value calculation section 32, a control method determination section 33, and a control method change command section . Necessary data is input to the data input unit 31 from the external database 7 . The external database 7 has a load database 71 and a system database 72 .

The load database 71 stores data on the loads 5 connected to the distribution line 1 . The data stored in the load database 71 includes, for example, power consumption for each hour of a week if the load is a factory, and power generated according to the weather if the load is a photovoltaic power generator. The system database 72 stores distribution line impedance, distribution system topology, measurement information sent from the LRT 4, SVR 2, and the sensor built-in switch 6, specifications such as the tap width of the SVR 2, set LDC setting values, and the like. It is

A data input unit 31 obtains necessary data from the database 7 . The data input unit 31 outputs data obtained from the database 7 to the setting value calculation unit 32 . The setting value calculation unit 32 calculates the setting value of the LDC based on the data input from the data input unit 31 . Here, the set value of the LDC is the reference voltage, the resistance value of the LDC, and the reactance value. When the control method change command unit 34 commands the set value of the LDC calculated by the set value calculation unit 32 to the SVR 2, the SVR 2, which has received the set value of the LDC, changes the constantly measured output voltage, passing current and resistance value. and the reactance value, the voltage at the center of the load is estimated, and the output voltage is controlled so that the voltage at the center of the load approaches the reference voltage.

FIG. 3 is an explanatory diagram showing voltages in the set value setting method according to the present embodiment. In FIG. 3, the horizontal axis is the position of the distribution line between the two SVRs 2, and the vertical axis is the voltage of the distribution line. In FIG. 3, the solid line is the voltage distribution due to the ideal send-out voltage. Here, the ideal send-out voltage is a send-out voltage in which tolerances to the voltage upper limit and the voltage lower limit are equal to the voltage drop across the SVR2. Assume that the allowable voltage width of the distribution line is 400V, the maximum voltage width between two SVR2 is 300V, the dead band width is 198V, and the LDC estimation error is 50V. The maximum voltage width between the two SVRs 2 is the maximum variation width of the voltage of the distribution line 1 between the two SVRs 2 . The dead band width is a voltage provided in voltage control so as not to perform an unnecessary voltage control operation against momentary voltage fluctuations, and is normally set to ±1.5% of the target voltage. In this embodiment, the target voltage of the distribution system is 6600V, so the dead band width is 198V. The LDC estimation error is the error between the ideal delivery voltage and the delivery voltage calculated by the LDC and depends on conditions such as the load 5 installed between the two SVRs 2 .

As shown in FIG. 3, when the maximum voltage width between the two SVRs 2 is 300 V, considering the dead band width and the LDC estimation error, the transmission voltage set by the setting value calculation unit 32 is the allowable voltage of the distribution line. It is possible to go out of range. The control method determination unit 33 determines whether or not the voltage obtained by adding the dead band width to the theoretical send-out voltage estimated by the set value calculation unit 32 deviates from the allowable voltage range of the distribution line. If the control method determination unit 33 determines that the theoretical feed-out voltage estimated by the set value calculation unit 32 deviates from the allowable voltage range of the distribution line, the control method change command unit 34 changes the voltage control method. is changed from the setting value setting method to the tap direct control method to the SVR2. Note that, when the control method determination unit 33 determines that the theoretical feed-out voltage estimated by the setting value calculation unit 32 does not deviate from the allowable range of the voltage of the distribution line, the setting value calculated by the setting value calculation unit 32 SVR2 is notified of the reference voltage, the resistance value of the LDC, and the reactance value.

FIG. 4 is an explanatory diagram showing voltages in the tap direct control method according to the present embodiment. In FIG. 4, the horizontal axis is the position of the distribution line between the two SVRs 2, and the vertical axis is the voltage of the distribution line. In FIG. 4, the solid line is the voltage distribution due to the theoretical send-out voltage. When the voltage control device 3 instructs the SVR 2 to change to the tap direct control method, the voltage control device 3 directly controls the tap of the SVR 2 based on the voltage of the distribution line 1 detected by the multiple switches 6 with built-in sensors. As shown in FIG. 4, when the step width of the tap is 100 V, for example, the SVR 2 sets the voltage with a width of ±100 V of the tap step width with respect to the theoretical output voltage estimated by the setting value calculation unit 32. be able to. By controlling in this way, it is possible to prevent the voltage of the distribution line from deviating from the allowable range.

FIG. 5 is a flow chart showing the procedure of the voltage control method according to this embodiment. The set value calculator 32 of the voltage control device 3 sets the operating period of the voltage control in step S1. The operation period may be, for example, 30 minutes, hours, days, weeks, months, or years. Further, the setting value calculation unit 32 may have a function of setting a division time for dividing into time slices according to the operation period. The division time is, for example, 1 minute, 10 minutes, or the like. Next, the setting value calculator 32 sets an arbitrary setting value in step S2. Here, the set values are the reference voltage, the resistance value of the LDC, and the reactance value. The setting value set in step S2 is arbitrary, but is determined based on the data input to the data input unit 31. FIG. Next, in step S3, the setting value calculator 32 calculates the theoretical send-out voltage _Vs in each time section. _Vs is calculated by the following formula (1).

V _s =V _ref +(R×ir _t +X×ii _t ) (1)

where V _ref is the reference voltage or system target voltage. R and X are the resistance and reactance values of the LDC, respectively. Also, ir _t and ii _t are the real and imaginary parts of the passing current at time section t, respectively.

Here, let N be the number of loads connected between the SVRs, and let n be an arbitrary integer from 1 to N corresponding to each load. Next, in step S4, the control method determination unit 33 calculates the determination voltage _Vna by adding the voltage change width _ΔVnt up to each load and the dead band width to the theoretical send-out voltage _Vs in each time section. FIG. 6 is an explanatory diagram showing a calculation example in the control method determination unit 33 of this embodiment. In the example shown in FIG. 6, the time section is at intervals of 1 minute. ir _t and ii _t change at each time slice. In addition, the maximum voltage width _Vst between SVRs also changes at each time cross section. V _ref , R and X are assumed to be constant at each time slice. Although not shown in FIG. 6, the width of the dead band is also constant at each time section. Next, in step S5, the control method determination unit 33 determines whether or not the determination voltage _Vna exceeds the upper limit or the lower limit of the wiring voltage in all time sections.

If it is determined in step S5 that the determination voltage _Vna in all time sections does not exceed the upper limit or lower limit of the wiring voltage (NO), the control method determination unit 33 selects the set value setting method as the voltage control method in step S6. select. On the other hand, if it is determined in step S5 that the determination voltage _Vna in all time sections exceeds the upper limit or lower limit of the wiring voltage (YES), the control method determination unit 33 selects the tap direct control method as the voltage control method in step S7. to select. In step S7, when the tap direct control method is selected as the voltage control method, the control method change command unit 34 commands the SVR 2 to change the voltage control method from the setting value setting method to the tap direct control method.

In the voltage control device configured in this way, even if the voltage of the distribution line estimated by the setting value setting method deviates from the allowable range, the voltage control method can cope with larger voltage fluctuations than the setting value setting method. Since it is possible to change to the tap direct control method, there is no need to add a new SVR. Note that the tap direct control method requires more communication than the set value setting method. The voltage control device of the present embodiment controls the wiring voltage by the setting value setting method with less communication traffic when the voltage of the distribution line estimated by the setting value setting method does not deviate from the allowable range. The tap direct control method is used only when the estimated distribution line voltage deviates from the allowable range, so the increase in communication traffic can be minimized. Furthermore, it can switch to an appropriate voltage control method according to changes in system conditions, such as an increase in the load connected to the distribution line, thereby avoiding voltage deviations from the allowable range without installing additional SVRs. be able to.

Note that the initial value of the setting value in the setting value calculation unit 32 may be past performance data, a predicted value, or the like. In addition, although the dead band width is added when calculating the determination voltage, a three-phase unbalance error, a measurement error, or the like may be added.

Embodiment 2.
The configuration of the voltage control device according to the second embodiment is the same as that of the voltage control device according to the first embodiment. In the voltage control device of the present embodiment, the operation of the control method determination section is different from that of the first embodiment.

FIG. 7 is a flow chart showing the steps of the voltage control method according to this embodiment. In the flowchart shown in FIG. 7, the operation of the voltage control device from step S1 to step S6 is the same as that of the first embodiment, so the explanation thereof will be omitted.

If it is determined in step S5 that the determination voltage _Vna exceeds the upper limit or the lower limit of the wiring voltage in all time sections (YES), the control method determination unit 33 proceeds to step S8. In step S8, the control method determination unit 33 determines whether or not to search for a new set value so that _Vna does not exceed the upper limit or lower limit of the wiring voltage in all time sections. If it is determined not to search for a new setpoint value in step S8 (NO), the control method determination unit 33 selects the tap direct control method as the voltage control method in step S7. On the other hand, if it is determined to search for a new setting value in step S8 (YES), the control method determination unit 33 sets a new setting value and sends it to the setting value calculation unit 32 in step S9. Here, as a method of determining a new setpoint value, for example, a method of formulating an optimization problem and using search logic such as metaheuristics such as linear programming and tabu search can be adopted. As a condition for not searching for a new setting value in step S8, when the number of searches reaches a predetermined upper limit, even if the setting value is updated, the maximum violation amount from the upper limit or lower limit of Vna is determined. It is conceivable that there is no improvement for more than the number of times in a row. Note that the new setting value determination method and the new setting value search conditions are not limited to these methods. In step S3, the setting value calculator 32 recalculates the theoretical send-out voltage _Vs in each time section using the new setting value.

In the voltage control apparatus configured as described above, voltage control can be performed using the set value setting method as much as possible, so that an increase in the amount of communication can be further suppressed.

Embodiment 3.
FIG. 8 is a schematic diagram of a voltage control device according to a third embodiment. The configuration of the voltage control device according to the present embodiment is obtained by removing the setting value calculation section from the configuration of the voltage control device according to the first embodiment and adding a measurement data collection section 35 . The measurement data collection unit 35 collects the voltage values of the distribution line 1 measured by the sensor built-in switch 6 in real time or at certain time intervals. The data input unit 31 adds the voltage value of the distribution line 1 collected by the measurement data collection unit 35 to the data input from the database 7 and outputs the control method determination unit 33 .

The procedure for selecting the voltage control method by the control method determination unit 33 is the same as in the first or second embodiment.

In the voltage control device configured in this way, since the voltage control method is selected based on the actual voltage of the distribution line in real time or at certain time intervals, unexpected voltage fluctuations occur in the distribution line. It is possible to prevent the upper or lower limit of the wiring voltage from being exceeded even when the wiring voltage is

In this embodiment, the voltage of the distribution line collected by the measurement data collection unit 35 is measured by the switch 6 with built-in sensor. It is not always necessary to use a switch with a built-in sensor to measure the voltage of the distribution line, and an inexpensive voltage sensor or the like may be used.

The voltage control device 3 according to Embodiments 1 to 3 is composed of a processor 100 and a storage device 101, as shown in FIG. 9 as an example of hardware. The storage device 101 includes a volatile storage device such as a random access memory and a non-volatile auxiliary storage device such as a flash memory (not shown). Also, an auxiliary storage device such as a hard disk may be provided instead of the flash memory. Processor 100 executes a program input from storage device 101 . In this case, the program is input from the auxiliary storage device to the processor 100 via the volatile storage device. Further, the processor 100 may output data such as calculation results to the volatile storage device of the storage device 101, or may store data in an auxiliary storage device via the volatile storage device.

Although this application describes various exemplary embodiments, the various features, aspects, and functions described in one or more embodiments are limited to the application of particular embodiments. can be applied to the embodiments alone or in various combinations.
Therefore, countless modifications not illustrated are envisioned within the scope of the technology disclosed in the present application. For example, modification, addition or omission of at least one component, extraction of at least one component, and combination with components of other embodiments shall be included.

1 distribution line, 2 SVR, 3 voltage control device, 4 LRT, 5 load, 6 switch with built-in sensor, 7 database, 10 voltage control system, 31 data input unit, 32 setting value calculation unit, 33 control method determination unit, 34 control method change command unit, 35 measurement data collection unit, 71 load database, 72 system database, 100 processor, 101 storage device.

Claims (5)

A voltage control device for controlling the output voltage of an automatic voltage regulator installed in a distribution line of a distribution system,
a data input unit into which data related to power consumption of loads connected to the distribution system and the distribution line are input;
a setting value calculation unit for calculating a setting value in a setting value setting method based on the data input to the data input unit;
calculating a voltage value of the distribution line based on the setting value calculated by the setting value calculation unit, and determining whether or not the calculated voltage value satisfies a voltage condition of the distribution system; Department and
A voltage control device comprising: a control method change command section for commanding a control method to be changed from the set value setting method to the tap direct control method based on the determination by the control method determination portion. The control method determination unit, when determining that the calculated voltage value does not satisfy the voltage condition of the distribution system, sets the new setting value and outputs the new setting value to the setting value calculation unit. The voltage control device according to claim 1, wherein 3. The voltage control device according to claim 1, wherein the data input unit collects voltage values at a plurality of positions on the distribution line. an automatic voltage regulator installed on a distribution line of a distribution system;
4. A voltage control system comprising the voltage control device according to claim 1, which controls the voltage of said automatic voltage regulator. A voltage control method for controlling the output voltage of an automatic voltage regulator installed in a distribution line of a distribution system,
a setting value calculation step of calculating a setting value in a setting value setting method based on data related to power consumption of loads connected to the distribution system and the distribution line;
calculating a voltage value of the distribution line based on the setting value calculated in the setting value calculating step, and determining whether or not the calculated voltage value satisfies a voltage condition of the distribution system; a step;
and a control method change command step for commanding a control method to be changed from the set value setting method to the tap direct control method based on the determination of the control method determination step.

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