Voltage Regulator

Abstract

To provide a voltage regulator capable of properly and autonomously regulating a voltage of a power distribution line regardless of calculation of a setting value.SOLUTION: A voltage regulator for regulating a voltage of a power distribution line of a power system includes: an acquisition unit that is located on a downstream side of the power distribution line from itself and acquires a voltage of the power distribution line from a voltage measuring instrument located between itself and adjacent another voltage regulator or a predetermined position of the power distribution line; a time measurement unit for measuring time when the voltage acquired by the acquisition unit deviates from a preset dead band area; and a regulator unit for performing regulation so as to decrease or increase a voltage of the power distribution line depending on whether the voltage acquired by the acquisition unit exceeds or falls below the dead band area when the time measured by the time measurement unit is longer than a preset operation time limit.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a voltage regulating device that regulates the voltage of a power distribution line based on the voltage of a power distribution line downstream of the voltage regulating device. [Background technology]

[0002] In the case of power system distribution lines, the line voltage drop increases as the line length from the substation increases, so multiple voltage regulators such as SVRs (Step Voltage Regulators) are installed according to the line length. Voltage regulators, for example, have an LDC (Line Voltage Drop Compensator) function that switches the transformer tap according to a setting value based on the estimated line voltage drop at the load center point.

[0003] Meanwhile, in the context of recent global environmental problems, distributed power sources such as photovoltaic (PV) power generation have been widely introduced. When distributed power sources are connected at various locations on a distribution line, the amount of power generated is affected by the weather, causing large fluctuations in the magnitude of the voltage and current in the distribution line as well as the phase of the current.

[0004] In addition, when a large number of capacitive and reactive loads are connected to a distribution line, the line voltage drop becomes more nonlinear, and in some cases the voltage minimum point may be closer to the substation than to the terminal. In this way, when distributed power sources cause large daily fluctuations in the system voltage and the manner in which the fluctuations occur becomes more diverse, the setting values ​​of voltage regulators become inappropriate, and unnecessary voltage regulation may occur frequently.

[0005] In response to this, Patent Document 1 discloses a voltage regulator that calculates impedance, which is a set value, based on the amount of solar radiation in a specified time period and information on voltage, current, etc. obtained from child stations in a distribution system, and adjusts taps using this impedance as the set value. Patent Document 2 discloses an automatic voltage regulator that determines set parameters based on measurement data on current, power factor, power, voltage, etc. sent from sensors installed in the distribution system and measurement data measured by the regulator itself.

[0006] On the other hand, Patent Document 3 discloses a voltage control system that repeatedly measures voltage at multiple points on a power distribution line, and if even one of the voltage points deviates from the appropriate range, activates a voltage control device located closest to the measurement point where the deviation is greatest. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2019-126229 A [Patent Document 2] JP 2010-220283 A [Patent Document 3] JP 2007-330067 A Summary of the Invention [Problem to be solved by the invention]

[0008] However, the technology disclosed in Patent Document 1 or 2 has a problem that the system configuration is complicated and the calculation of the setting value is cumbersome. Also, the technology disclosed in Patent Document 3 requires a control device that comprehensively controls a plurality of voltage control devices.

[0009] The present invention has been made in view of the above circumstances, and has an object to provide a voltage regulator capable of properly and autonomously regulating the voltage of a power distribution line without relying on the calculation of a setting value. [Means for solving the problem]

[0010] The voltage regulating device of the present invention is a voltage regulating device that adjusts the voltage of a distribution line of a power system, and includes an acquisition unit that acquires the voltage of the distribution line from a voltage measuring device that is located downstream of the voltage regulating device itself and is located between the voltage regulating device itself and another adjacent voltage regulating device or a predetermined position on the distribution line, a timing unit that measures the time that the voltage acquired by the acquisition unit deviates from a predetermined dead zone area, and an adjustment unit that, when the time measured by the timing unit is longer than a predetermined operating time limit, adjusts the voltage of the distribution line so that it is lowered or raised depending on whether the voltage acquired by the acquisition unit is above or below the dead zone area.

[0011] In the present invention, a voltage is acquired from an arbitrary voltage measuring device located downstream of the device in the distribution line, and located upstream of another voltage regulating device if there is another voltage regulating device adjacent to the downstream side, or located upstream of a predetermined position on the distribution line if there is no other adjacent voltage regulating device. Then, if the acquired voltage deviates from the dead zone for longer than the operating time limit, the voltage of the distribution line is increased or decreased depending on the direction in which the acquired voltage deviates from the dead zone. This adjusts the actual voltage on the downstream side of the distribution line to fall within the dead zone.

[0012] In the voltage adjustment device of the present invention, the acquisition unit acquires voltages from a plurality of the voltage measuring devices, and the adjustment unit adjusts the voltage when the time measured by the timing unit for any of the voltage measuring devices is longer than the operating time limit.

[0013] In the present invention, when a voltage acquired from any of a plurality of voltage measuring devices located downstream of the distribution line deviates from a dead zone for a period longer than an operating time limit, the voltage of the distribution line is adjusted so that the actual voltages at a plurality of positions downstream of the distribution line are adjusted to fall within the dead zone.

[0014] In the voltage regulating device of the present invention, when there is a mixture of voltage measuring instruments where the voltages acquired by the acquisition unit are above the dead band region and below the dead band region, the timing unit does not measure time for any of the voltage measuring instruments.

[0015] In the present invention, when some of the voltage measuring instruments located downstream of the power distribution line measure voltages that are above and below the dead zone for a period longer than the operating time limit, the time that any of the voltage measuring instruments deviate from the dead zone is not measured, thereby suppressing unnecessary voltage fluctuations on the power distribution line.

[0016] In the voltage adjustment device of the present invention, when there is a mixture of voltage measuring instruments whose voltages acquired by the acquisition unit are above the dead zone and below the dead zone, the timing unit measures the time for the voltage measuring instrument with the highest preset priority among the voltage measuring instruments whose voltages acquired by the acquisition unit deviate from the dead zone.

[0017] In the present invention, priorities are set in advance for multiple voltage measuring instruments located downstream of the distribution line, and when some of the voltage measuring instruments have voltages that are above and below the dead zone for longer than the operating time limit, the time that the voltage measuring instrument with the highest priority among them deviates from the dead zone is timed, thereby adjusting the actual voltage at the position with the highest priority downstream of the distribution line to fall within the dead zone.

[0018] The voltage adjustment device of the present invention further includes a holding unit that holds the deviation direction and deviation amount of the dead zone for a voltage measuring instrument in which the voltage acquired by the acquisition unit deviates from the dead zone, and the adjustment unit calculates the sum of the deviation amounts held by the holding unit for each deviation direction held by the holding unit, and adjusts the voltage based on the sign and magnitude of the difference between the calculated sums.

[0019] In the present invention, for a voltage measuring instrument whose acquired voltage deviates from the dead zone, the deviation direction and deviation amount are stored. For a plurality of voltage measuring instruments located downstream of the distribution line, the sum of the stored deviation amounts is calculated for each deviation direction, and the voltage of the distribution line is increased or decreased based on which of the calculated sums is larger. In this way, the deviation amount from the dead zone for each voltage measuring instrument is adjusted so that the upper limit and lower limit are offset. Effect of the Invention

[0020] According to the present invention, it is possible to appropriately and autonomously adjust the voltage of a power distribution line without relying on the calculation of a setting value. [Brief description of the drawings]

[0021] [Figure 1] 1 is a block diagram showing an example of the configuration of a voltage adjusting device according to a first embodiment. [Diagram 2] 4 is a timing chart showing how the voltage of the power distribution line is regulated within the dead zone. [Diagram 3] 13 is a graph illustrating the change characteristics of an operation time limit of an integral time limit type. [Figure 4] 11 is a table showing combinations of modes in which the measurement results of each voltage measuring device deviate from the dead zone. [Diagram 5] 5 is a flowchart showing a processing procedure of a CPU for adjusting a voltage of a power distribution line by the voltage regulating device according to the first embodiment. [Figure 6] 10 is a flowchart showing a processing procedure of a CPU for adjusting a voltage of a power distribution line by a voltage regulating device according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] The present invention will now be described in detail with reference to the drawings showing embodiments thereof. (Embodiment 1) 1 is a block diagram showing a configuration example of a voltage regulating device according to embodiment 1. A voltage regulating device 100, which is a so-called SVR, includes a transformer 110 with a tap that transforms the voltage of a distribution line of a power system, a tap changer 111 that switches the tap of the transformer 110, and a control unit 10 that issues a command to the tap changer 111 to switch the tap.

[0023] Voltage measuring instruments M_1, M_2, M_3 are connected to the distribution line 300 on the opposite side (downstream side) of the substation 200 from the transformer 110, corresponding to the sections S_1, S_2, S_3, respectively. A plurality of loads (not shown) are further connected to each of the sections S_1, S_2, S_3 (same below). The number of sections in the distribution line 300 is not limited to three. Another adjacent voltage regulating device 101 is connected between the distribution line 300 and a distribution line 301 further downstream of the distribution line 300. Voltage measuring instruments M_11, M_12, ​​... are connected to the distribution line 301, corresponding to the sections S_11, S_12, ..., respectively.

[0024] Voltage measuring instruments M_21, M_22, and M_23 are connected to the distribution line 302 on the substation 200 side (upstream side) from the transformer 110, corresponding to sections S_21, S_22, and S_23, respectively. The number of sections in the distribution line 302 is not limited to three. Another adjacent voltage regulating device 102 is connected between the distribution line 302 and a distribution line 303 further upstream of the distribution line 302.

[0025] The voltage measuring instruments M_1, M_2, M_3 and M_21, M_22, M_22 measure the voltages of the power distribution lines 300 and 302 to which they are connected, and wirelessly transmit the measured voltages to the voltage regulating device 100 in a multi-hop manner, for example, by polling. Each of the voltage measuring instruments M_1, M_2, M_3 and M_21, M_22, M_22 may directly transmit to the voltage regulating device 100 wirelessly or may transmit via a wire.

[0026] Each voltage measuring instrument may be configured for exclusive use using a measuring transformer or a resistive voltage divider, or may be configured by adding a voltage measuring circuit to existing equipment such as a switching station substation, a pole transformer, etc. By determining the connection position of each voltage measuring instrument in consideration of the capacity and load characteristics of the contracted customers for each section to which each is connected, it becomes possible to more accurately adjust the voltage of the distribution lines 300 and 302.

[0027] The control unit 10 includes a CPU (Central Processing Unit) 11 that controls the entire device. The CPU 11 is connected to a ROM (Read Only Memory) 12 that stores information such as a control program, a RAM (Random Access Memory) 13 that stores temporarily generated information, and a timer 14 that measures elapsed time, etc., via a bus. The control unit 10 may be configured to include a microcomputer having a CPU. The CPU 11 or the microcomputer is configured to execute a computer program having a predetermined processing procedure.

[0028] The CPU 11 is also connected via a bus to an output unit 15 for issuing a switching command to the tap changer 111, and a communication unit 16 for communicating with the voltage measuring instruments M_1, M_2, M_3, M_21, M_22, and M_23. The CPU 11 realizes the function of a switching command unit that issues a switching command by software processing. The CPU 11 further acquires voltages, which are the measurement results measured by each voltage measuring instrument, by wireless communication or wired communication using the communication unit 16.

[0029] The control unit 10 of the voltage regulating device 100 configured as described above detects the voltages of the distribution lines 300, 302 before and after tap changing of the transformer 110 using a measurement transformer (not shown), for example, and determines the electric power station direction, which is the connection direction of the substation 200, based on the change in the detected voltage. The electric power station direction may be reversed before and after so-called system switching. Various methods have been proposed for determining the electric power station direction, and a description thereof will be omitted here.

[0030] 1, when the control unit 10 determines that the direction of the distribution line 302 side is the direction of the sub-electric power station, the control unit 10 determines that the distribution line 300 side is the downstream side. The control unit 10 acquires the voltage of the distribution line 300 at intervals of, for example, one second from voltage measuring instruments M_1, M_2, and M_3 located between the distribution line 302 side and another adjacent voltage regulating device 101 on the downstream side.

[0031] The voltage measuring instruments from which the control unit 10 acquires the voltage may be, for example, voltage measuring instruments M_1 and M_2, or may be voltage measuring instruments M_1 and M_3, or may be voltage measuring instruments M_2 and M_3. When there is no voltage adjustment device 101 on the downstream side, the control unit 10 may acquire the voltage of the power distribution line 300 from, for example, voltage measuring instruments M_1, M_2, and M_3, and may further acquire the voltage of the power distribution line 301 from voltage measuring instruments M_11, M_12, ​​and so on in addition to these. An appropriate position further downstream than the most downstream voltage measuring instrument from which the control unit 10 acquires the voltage corresponds to the predetermined position.

[0032] For example, if any of the acquired voltages deviates from a dead band region (hereinafter simply referred to as a dead band) for longer than a preset operating time limit, the control unit 10 raises or lowers the voltage of the distribution line 300 by raising or lowering the tap depending on whether the acquired voltage exceeds or falls below the dead band.

[0033] Contrary to the example shown in Fig. 1, when the control unit 10 determines that the direction of the distribution line 300 side is the electric power station direction, the control unit 10 acquires the voltage of the distribution line 302 from the voltage meters M_21, M_22, and M_23 located between the distribution line 302 side and another adjacent voltage adjustment device 102 on the downstream side, with the distribution line 302 side being the downstream side. The voltage meters from which the control unit 10 acquires the voltage may be, for example, the voltage meters M_21 and M_22, the voltage meters M_21 and M_23, or the voltage meters M_22 and M_23. The control unit 10 raises or lowers the voltage of the distribution line 302 by raising or lowering the tap depending on whether the acquired voltage is above or below the dead band.

[0034] FIG. 2 is a timing chart showing how the voltage of the power distribution line 300 is adjusted to within the dead zone. The vertical axis of FIG. 2 represents the voltage of the power distribution line 300, and the horizontal axis represents time (t). Va represents the target voltage (i.e., reference voltage: 6600V), and Vb1 and Vb2 represent the lower and upper limits of the dead zone, respectively. In the example shown in FIG. 2, the width of the dead zone is ±1% of the target voltage, and the lower and upper limits are 6534V and 6666V, respectively. Times t1 and t3 are the times when the voltage acquired from one voltage meter starts to exceed the upper limit of the dead zone and starts to fall below the lower limit, respectively. The time from time t1 to t2 and the time from time t3 to t4 correspond to the operating time limit.

[0035] For example, if the deviation state in which the voltage acquired from one voltage meter exceeds the upper limit of the dead band continues for the operating time limit from time t1 to t2, the control unit 10 switches the tap of the transformer 110 in a direction to lower the tap, thereby decreasing the voltage. As a result, the voltage of the distribution line 300 decreases in a step-like manner at time t2. On the other hand, if the deviation state in which the voltage acquired from one voltage meter falls below the lower limit of the dead band continues for the operating time limit from time t3 to t4, the control unit 10 switches the tap of the transformer 110 in a direction to raise the tap, thereby increasing the voltage. As a result, the voltage of the distribution line 300 increases in a step-like manner at time t4.

[0036] When the voltage acquired from one voltage measuring device changes from a deviation state above the upper limit of the dead band to a state below the upper limit, the control unit 10 temporarily stops timing the duration of the deviation state, and resumes timing when the voltage exceeds the upper limit of the dead band again. Similarly, when the voltage acquired from one voltage measuring device changes from a deviation state below the lower limit of the dead band to a state above the lower limit, the control unit 10 temporarily stops timing the duration of the deviation state, and resumes timing when the voltage falls below the lower limit of the dead band again.

[0037] The method for timing the duration of the deviation state may be a fixed time type that measures time over a fixed period of time, or an integral time type in which the action time limit changes according to the magnitude of the deviation voltage that deviates from the dead zone. Figure 3 is a graph illustrating the change characteristics of the action time limit of the integral time type. The horizontal axis of Figure 3 represents the deviation voltage, which is the deviation of the voltage deviating from the reference voltage and is expressed as a ratio (±%) to the reference voltage, and the vertical axis represents the action time limit (seconds). The action time limit is expressed by the following formula (1).

[0038] Operating time limit (seconds) = integral constant (seconds·%) / {deviation voltage (±%) - dead band (±%)}…(1)

[0039] The curve in Figure 3 shows an inverse time characteristic where the larger the deviation voltage, the shorter the operation time limit. Here, the integral constant is 200 (sec·%) and the dead band is 1 (±%), so for example, when the deviation voltage is 6 (±%), the operation time limit is 40 seconds (see the thick solid line in the figure).

[0040] In the above example, the voltage acquired from one voltage measuring device, i.e., the measurement result of one voltage measuring device, is explained as being outside the dead zone, but the manner in which the measurement results of the three voltage measuring devices M_1, M_2, and M_3 are outside the dead zone is not uniform. This will be explained using diagrams and tables.

[0041] Fig. 4 is a chart showing combinations of the manner in which the measurement results of each voltage measuring device deviate from the dead zone. There are three types of deviation from the dead zone: "no deviation," "deviation from the upper limit (of the dead zone)," and "deviation from the lower limit (of the dead zone)." The operation when the measurement result of any voltage measuring device deviates from the dead zone and continues to deviate for the operating time limit is described as "time-limited operation."

[0042] A "-" for the time-limited operation corresponds to a case where the control unit 10 does not issue a switching command. A circle in the diagram indicates that a voltage measuring instrument that corresponds to each mode of deviation from the dead zone is present. A circle in parentheses indicates that the case includes both a case where a voltage measuring instrument that corresponds to each mode of deviation from the dead zone is present and a case where it is not present.

[0043] In the case of No. 1, the measurement result of none of the voltage measuring instruments deviates from the dead band, and no switching command is issued. In the case of No. 2, when the measurement result of at least one voltage measuring instrument deviates from the upper limit value of the dead band, and none of the measurement results deviates from the lower limit value of the dead band, and the deviation state in which the measurement result of any of the voltage measuring instruments deviates from the upper limit value of the dead band continues for the operating time limit, the control unit 10 issues a switching command to step-down. In the case of No. 3, when the measurement result of at least one voltage measuring instrument deviates from the lower limit value of the dead band, and none of the measurement results deviates from the upper limit value of the dead band, and the deviation state in which the measurement result of any of the voltage measuring instruments deviates from the lower limit value of the dead band continues for the operating time limit, the control unit 10 issues a switching command to step-up.

[0044] In the case of number 4, the measurement result of at least one voltage measuring instrument is outside the upper limit of the dead zone, and the measurement result of at least one voltage measuring instrument is outside the lower limit of the dead zone. In this case, the first method is not to measure the duration of the deviation state of deviation from the dead zone for any voltage measuring instrument, and the control unit 10 does not issue a switching command. The second method is to issue a switching command for step-up or step-down when the deviation state of the measurement result of any voltage measuring instrument outside the dead zone continues for the operation time limit. The third method is to measure the duration of the deviation state of deviation from the dead zone for the voltage measuring instrument with the highest priority among the voltage measuring instruments whose measurement result deviates from the dead zone, and when this deviation state continues for the operation time limit, the control unit 10 issues a switching command for step-up or step-down.

[0045] Normally, an upper limit is set for the path length between the voltage regulator 100 and the voltage regulators 101 and 102 so that the case of number 4 does not occur, but if the occurrence of the case of number 4 is still expected, a different reference voltage and dead zone may be set for each voltage meter. For example, the reference voltage may be lowered or the dead zone may be widened for a voltage meter with a longer path length from the voltage regulator 100.

[0046] Next, the operation of the control unit 10 of the voltage regulating device 100 according to the first embodiment configured as described above will be described with reference to a flowchart. The following process is executed by the CPU 11 in accordance with a control program prestored in the ROM 12. Fig. 5 is a flowchart showing the process procedure of the CPU 11 for adjusting the voltage of the power distribution line 300 in the voltage regulating device 100 according to the first embodiment.

[0047] The process in FIG. 5 is started, for example, every second. In the figure, the voltage measuring instruments are abbreviated as measuring instruments. The duration of the deviation state is abbreviated as deviation time. Furthermore, the upper limit value and the lower limit value are abbreviated as upper limit and lower limit, respectively. The time during which the measurement result of each voltage measuring instrument deviates from the dead zone is individually timed by timer 14, and the time measurement can be interrupted and resumed. Priorities are set in advance for voltage measuring instruments M_1, M_2, M_3 and M_21, M_22, M_22.

[0048] When the process in Fig. 5 is started, the CPU 11 judges whether tap changing is in progress, i.e., whether a predetermined time has not elapsed since the issuance of a switching command (S11), and if tap changing is in progress (S11: YES), ends the process in Fig. 5 without performing any special process. The reason why no special process is performed within the predetermined time after the issuance of the switching command is that the voltage of the distribution line 300 changes suddenly due to tap changing and becomes unstable.

[0049] If tap switching is not in progress (S11: NO), CPU 11 acquires the measurement results of the voltage of distribution line 300 from downstream voltage measuring instruments M_1, M_2, and M_3 (S12: corresponds to an acquisition unit). If the measurement results cannot be acquired within a predetermined collection time, the previous acquisition result may be used. Next, CPU 11 determines whether the measurement result of one voltage measuring instrument deviates from the dead band (S13), and if it does not deviate (S13: NO), if the deviation time is being measured for that voltage measuring instrument, the measurement is interrupted (S14), and the process proceeds to step S19 described later.

[0050] If the measurement result of one voltage measuring instrument is outside the dead zone (S13: YES), CPU 11 judges whether or not the deviation time is being counted for that voltage measuring instrument (S15). If the deviation time is not being counted (S15: NO), CPU 11 resumes or starts counting depending on whether the deviation time counting is paused (S16: corresponding to the timing unit), and then proceeds to step S19. In step S16, the speed of counting can be increased or decreased depending on the amount of deviation, i.e., the magnitude of the deviation voltage, to perform integral time limit type timing. For example, when using a countdown timer that counts down the remaining time per unit time, the value counted down per unit time can be increased or decreased depending on the magnitude of the deviation voltage.

[0051] If the deviation time is being measured for one voltage measuring instrument (S15: YES), CPU 11 determines whether the deviation time has passed the operating time limit (S18). If the operating time limit has not passed (S18: NO), CPU 11 determines whether each process from step S13 onwards has been completed for all voltage measuring instruments for which measurement results have been obtained (S19).

[0052] If the processes have not been completed for all voltage measuring instruments for which measurement results have been obtained (S19: NO), CPU 11 moves the process to step S13 to perform the processes for another measuring instrument. On the other hand, if the processes have been completed for all voltage measuring instruments for which measurement results have been obtained (S19: YES), CPU 11 determines whether or not, among the voltage measuring instruments for which measurement results deviate from the dead band, there is a mixture of those that deviate from the upper limit and those that deviate from the lower limit (S20).

[0053] If there are no deviations from the upper and lower limits (S20: NO), CPU 11 ends the process in FIG. 5. On the other hand, if there are deviations from the upper and lower limits (S20: YES), CPU 11 identifies the voltage measuring instrument set to the highest priority among the voltage measuring instruments whose measurement results deviate from the dead zone (S21). Next, CPU 11 stops measuring the deviation time for voltage measuring instruments with a priority lower than the highest priority (S22), and then ends the process in FIG. 5. As a result, measuring the deviation time continues only for the voltage measuring instrument with the highest priority. In step S22, measuring the deviation time may be interrupted rather than stopped.

[0054] If the deviation time of the dead band has passed the operation time limit in step S18 (S18: YES), CPU 11 judges whether the measurement result has deviated from the upper limit of the dead band (S23). If the upper limit of the dead band has been deviated (S23: YES), CPU 11 issues a switching command to command a voltage drop (S24: corresponds to an adjustment unit). On the other hand, if the lower limit of the dead band has been deviated (S23: NO), CPU 11 issues a switching command to command a voltage increase (S25: corresponds to an adjustment unit). When the process of step S24 or S25 is completed, CPU 11 stops counting the deviation time of the dead band for all voltage measuring instruments that have acquired the measurement results (S26), and then ends the process of FIG. 5.

[0055] 5 is based on the assumption that the direction of the electric power station is the direction toward the distribution line 302, but the same applies to the case where the direction of the electric power station is the direction toward the distribution line 300. That is, in step S12, the measurement results of the voltage of the distribution line 302 are obtained from the downstream voltage measuring instruments M_21, M_22, and M_23. Also, the voltage increase and decrease switching command is to increase and decrease the voltage of the distribution line 302 with respect to the voltage of the distribution line 300.

[0056] In step S20 in Fig. 5, it is determined whether the measurement results include a mixture of those that deviate from the upper limit and those that deviate from the lower limit of the dead band, but the process in Fig. 5 may be ended without making this determination. In this case, when it is determined in step S18 executed later that the deviation time for one voltage measuring instrument has exceeded the operating time limit, a command to switch between step-down or step-up is issued in step S24 or S25.

[0057] 5, the measurement of the deviation time is stopped or interrupted for the voltage measuring instruments other than the voltage measuring instrument with the highest priority, but the measurement of the deviation time may be stopped or interrupted for all the voltage measuring instruments that have acquired the measurement results. In this case, the switching command is not issued.

[0058] As described above, according to the first embodiment, the voltage is acquired from the voltage measuring devices M_1, M_2, and M_3 located downstream of the own device on the power distribution line 300 and upstream of another voltage regulating device 101 connected downstream, and when the acquired voltage deviates from the dead zone for a period longer than the operating time limit, the voltage of the power distribution line 300 is increased or decreased depending on the deviation direction of the acquired voltage from the dead zone. This allows the actual voltage on the downstream side of the power distribution line 300 to be adjusted to fall within the dead zone. Therefore, it becomes possible to appropriately and autonomously adjust the voltage of the power distribution line 300 without relying on the calculation of a set value.

[0059] Moreover, according to the first embodiment, when the voltage acquired from any one of the three voltage measuring devices M_1, M_2, and M_3 located downstream of the distribution line 300 deviates from the dead zone for a period longer than the operating time limit, the voltage of the distribution line 300 is adjusted. Therefore, the actual voltages at the three positions downstream of the distribution line 300 can be adjusted to fall within the dead zone.

[0060] Furthermore, according to the first embodiment, when the measurement results of the three voltage measuring instruments M_1, M_2, and M_3 located downstream of the power distribution line 300 are both above and below the dead zone for longer than the operating time limit, it is possible to prevent any of the voltage measuring instruments from timing the time of deviation from the dead zone. In this case, unnecessary voltage fluctuations in the power distribution line 300 can be suppressed.

[0061] Furthermore, according to the first embodiment, priorities are set in advance for the three voltage measuring instruments M_1, M_2, and M_3 located downstream of the power distribution line 300, and when some of the voltage measuring instruments have acquired voltages that are above and below the dead zone for longer than the operating time limit, the time that the voltage measuring instrument with the highest priority among them deviates from the dead zone is timed. Therefore, the actual voltage at the position with the highest priority on the downstream side of the power distribution line 300 can be adjusted to fall within the dead zone.

[0062] (Embodiment 2) In the first embodiment, a command to step down or step up is issued depending on the direction in which the measurement result of one voltage measuring device deviates from the dead zone. In contrast, in the second embodiment, a command to switch between stepping down or stepping up is issued depending on the direction and amount of deviation in the measurement result of one or more voltage measuring devices deviating from the dead zone. The block configuration of the voltage regulator according to the second embodiment is similar to that of the voltage regulator 100 according to the first embodiment, and therefore, illustration is omitted, and the same reference numerals are used to designate parts corresponding to the first embodiment, and description thereof is omitted.

[0063] In the second embodiment, the control unit 10 stores the deviation direction and deviation amount each time it acquires a measurement result for a voltage measuring instrument that is timing the deviation time from the dead zone, and when the measurement result for one voltage measuring instrument indicates that the deviation state from the dead zone continues for the operating time limit, it performs a predetermined calculation to determine whether to step down or step up the voltage. Specifically, the control unit 10 calculates the sum of the deviation amounts from the upper limit value and the lower limit value of the dead zone for all voltage measuring instruments from which it has acquired measurement results, and issues a switching command to step down or step up the voltage based on the sign and magnitude of the difference between the calculated sums.

[0064] The operation of the control unit 10 described above will be described below with reference to a flowchart showing the operation. Fig. 6 is a flowchart showing the processing procedure of the CPU 11 for adjusting the voltage of the power distribution line 300 in the voltage adjustment device 100 according to the second embodiment. The processing from steps S31 to S36 shown in Fig. 6 is equivalent to the processing from steps S11 to S16 shown in Fig. 5 of the first embodiment, and therefore most of the description of these steps will be omitted.

[0065] When the process of Fig. 6 is started, CPU 11 executes the process from step S31 to step S35 in the same manner as the process from step S11 to step S15. When the measurement result of one voltage measuring instrument deviates from the dead zone (S33: YES) and the deviation time is being measured for that voltage measuring instrument (S35: YES), CPU 11 stores the deviation direction and deviation amount in RAM 13 (S37: corresponding to the holding unit). The deviation direction here is two-way, and corresponds to whether the measurement result is above the upper limit value or below the lower limit value of the dead zone. The deviation amount may be, for example, a deviation voltage that deviates from the dead zone.

[0066] Thereafter, CPU 11 determines whether the deviation time has passed the operating time limit (S38). If the operating time limit has not passed (S38: NO), CPU 11 determines whether the processes from step S33 onward have been completed for all voltage measuring instruments for which measurement results have been obtained (S39). If the processes have not been completed for all voltage measuring instruments (S39: NO), CPU 11 moves the process to step S33 to perform the processes for another measuring instrument. On the other hand, if the processes have been completed for all voltage measuring instruments (S39: YES), CPU 11 ends the process of FIG. 6.

[0067] If the deviation time of the dead zone has passed the operation time limit in step S38 (S38: YES), the CPU 11 calculates the sum of the deviation amount of deviation from each of the upper and lower limits of the dead zone separately based on the deviation direction and deviation amount stored in step S37 (S41). Next, the CPU 11 calculates the difference between each sum of the deviation amounts (S42) and issues a switching command to command increase / decrease voltage based on the sign and magnitude of the calculated difference (S43: corresponding to the adjustment unit). Then, the CPU 11 stops measuring the deviation time of the dead zone for all voltage measuring instruments that have acquired the measurement results (S44), and then ends the processing of FIG. 6.

[0068] As described above, according to the second embodiment, the deviation direction and deviation amount are stored for a voltage measuring instrument whose measurement result deviates from the dead zone. The sum of the stored deviation amounts for a plurality of voltage measuring instruments located downstream of the distribution line 300 is calculated for each deviation direction, and the voltage of the distribution line 300 is increased or decreased based on which of the calculated sums is larger. This makes it possible to adjust the deviation amount from the dead zone for each voltage measuring instrument so that it is offset between the upper limit side and the lower limit side.

[0069] In the first and second embodiments, an example using an SVR as a voltage regulator has been described, but the same applies to cases where a thyristor-type voltage regulator (TVR = Thyristor type step Voltage Regulator) or other voltage regulators are used. Examples of other voltage regulators include an SSR (Step Switched Reactor) and an ShR (Shunt Reactor) that lower the voltage of a distribution line by connecting a reactor in parallel to a power transmission line via a switch. Other examples include an SSC (Step Switched Capacitor) that raises the voltage of a distribution line by connecting a capacitor in parallel to the distribution line via a switch, and an SVC (Static Var Compensator) that adjusts the voltage of a distribution line by adjusting reactive power using a leading-phase capacitor and a reactor.

[0070] Furthermore, in the first and second embodiments, the voltage regulating device 100 determines whether the measurement results of each voltage measuring device have deviated from the dead zone and measures the time of deviation. However, these determinations and measurements may also be performed by each voltage measuring device. In this case, the amount of communication between the voltage regulating device 100 and each voltage measuring device can be significantly reduced.

[0071] The embodiments disclosed herein are illustrative in all respects and should not be considered as limiting. The scope of the present invention is indicated by the claims, not by the above meaning, and is intended to include all modifications within the meaning and scope of the claims. In addition, the technical features described in each embodiment can be combined with each other. [Explanation of symbols]

[0072] 100,101,102 voltage regulator, 110 transformer, 111 tap changer, 10 control unit, 11 CPU, 12 ROM, 13 RAM, 14 timer, 15 output unit, 16 communication unit, 200 substation, 300,301,302,303 distribution line, M_1,M_2,M_3,M_11,M_12,M_13,M_21,M_22,M_23 voltage measuring instrument, S_1,S_2,S_3,S_11,S_12,S_13,S_21,S_22,S_23 section

Claims

1. A voltage regulator that adjusts the voltage of a distribution line of a power system, an acquisition unit that acquires a voltage of the power distribution line from a voltage measuring device that is located downstream of the acquisition unit and between the acquisition unit and another adjacent voltage regulating device or a predetermined position on the power distribution line; a timer that measures a time during which the voltage acquired by the acquisition unit deviates from a preset dead zone; an adjustment unit that adjusts the voltage of the power distribution line so as to step down or step up depending on whether the voltage acquired by the acquisition unit is above or below the dead zone when the time measured by the timing unit is longer than a preset operation time limit; Equipped with The acquisition unit acquires voltages from a plurality of the voltage measuring devices, the adjustment unit adjusts a voltage when the time measured by the timer unit for any one of the voltage measuring devices is longer than the operating time limit; When there are voltage meters whose voltages acquired by the acquisition unit are higher than the dead band region and voltage meters whose voltages are lower than the dead band region, the timer does not measure time for any of the voltage meters. Voltage regulator.

2. A voltage regulator for adjusting the voltage of a distribution line of an electric power system, comprising: an acquisition unit that acquires a voltage of the power distribution line from a voltage measuring device that is located downstream of the acquisition unit and between the acquisition unit and another adjacent voltage regulating device or a predetermined position on the power distribution line; a timer that measures a time during which the voltage acquired by the acquisition unit deviates from a preset dead zone; an adjustment unit that adjusts the voltage of the power distribution line so as to step down or step up depending on whether the voltage acquired by the acquisition unit is above or below the dead zone when the time measured by the timing unit is longer than a preset operation time limit; Equipped with The acquisition unit acquires voltages from the plurality of voltage measuring devices, the adjustment unit adjusts a voltage when the time measured by the timer unit for any one of the voltage measuring devices is longer than the operating time limit; When there are a mixture of voltage measuring instruments whose voltages acquired by the acquisition unit are higher than the dead zone and voltage measuring instruments whose voltages are lower than the dead zone, the timing unit measures the time for the voltage measuring instrument having the highest preset priority among the voltage measuring instruments whose voltages acquired by the acquisition unit deviate from the dead zone. Voltage regulator.

3. a storage unit that stores a deviation direction and a deviation amount of the dead band region for a voltage measuring instrument whose voltage acquired by the acquisition unit deviates from the dead band region, The adjustment unit calculates a sum of the deviation amounts held by the holding unit for each deviation direction held by the holding unit, and adjusts a voltage based on a sign and a magnitude of a difference between the calculated sums. The voltage regulator according to claim 1 or 2.

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