Voltage regulation method and power system in low-voltage distribution system

Abstract

In a power distribution system including a low-voltage power distribution system in which distributed power supplies are connected, as a method for realizing high-precision, low-variation voltage management for a low-voltage power distribution system, the following steps are repeated: a) a step for measuring the voltage value in the low-voltage power distribution system using a voltage-measuring device installed in each low-voltage power distribution system; b) a step for measuring the voltage value in a high-voltage power distribution system, to which the low-voltage power distribution system is connected, using a prescribed high-voltage device provided to the high-voltage power distribution system; c) a step for calculating the respective operating parameters of a voltage regulator provided to the high-voltage power distribution system, a PCS provided to the distributed power supply, and a SVG provided to the low-voltage power distribution system on the basis of the measurement values in step a) and step b); and d) a step for operating the voltage regulator, the PCS, and the SVG on the basis of the operating parameters calculated in step c), thereby smoothing changes in the voltage value over time in at least a part of a prescribed control range while maintaining the voltage value in the low-voltage power distribution system within the control range over time.

Description

[Technical field]

[0001] The present invention relates to voltage regulation in a power distribution system, and more particularly to voltage regulation in a power distribution system including a plurality of low-voltage power distribution systems each connected to a distributed power source. [Background technology]

[0002] In recent years, distributed power sources such as photovoltaic power generation systems and electric vehicles have become increasingly popular. Influenced by carbon neutral declarations and other factors, the number of distributed power sources connected to the power grid is increasing.

[0003] It is known that as the number of distributed power sources connected to a power distribution system increases, short-period power injections occur frequently, causing the voltage fluctuation range to expand and exceed the adjustment range of the voltage regulators installed in the power distribution system, making voltage management difficult.

[0004] A voltage management system is already known in which a smart inverter supplies reactive power to a power distribution system, thereby maintaining a voltage regulator in the power distribution system in a state where a margin of power is always ensured (see, for example, Patent Document 1).

[0005] The number of distributed power sources connected to the power distribution system is expected to continue to increase in the future. This increase not only causes the reverse power flow described above, but also may cause malfunctions and failures of consumer devices due to voltage excess or shortage, or intensified voltage fluctuations, such as frequent instantaneous spike-like fluctuations.

[0006] However, in Japan, the voltage of low-voltage distribution systems to which individual consumers connect their equipment is currently only managed as a 30-minute average value in accordance with the Electricity Business Act.

[0007] In addition, the voltage of low-voltage distribution systems is currently controlled by using high-voltage voltage regulators such as SVRs (Step Voltage Regulators), TVRs (Thyristor type step Voltage Regulators), and TSC (Thyristor Switched Capacitors)-type SVCs (Static Var Compensators) installed in upstream high-voltage distribution systems. However, because the control does not involve monitoring the actual voltage profile of each low-voltage distribution system, there are problems such as deviations from the control range and reliable and optimal voltage control not always being achieved.

[0008] On the other hand, from the perspective of energy conservation, a voltage management method called Conservation Voltage Reduction (CVR), which operates the voltage in low-voltage systems near the lower limit of the standard voltage, is being introduced mainly in the United States. However, this is not necessarily effective against spike-like voltage fluctuations. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] JP 2021-132498 A Summary of the Invention

[0010] The present invention has been made in view of the above problems, and has an object to realize voltage management of a low-voltage power distribution system with high accuracy and low fluctuation, which has a higher energy saving effect than conventional methods.

[0011] In order to solve the above-mentioned problems, a first aspect of the present invention is a method for adjusting voltages in a plurality of low-voltage distribution systems of a distribution system including a plurality of low-voltage distribution systems, each of which is connected to a distributed power source, and a high-voltage distribution system to which the plurality of low-voltage distribution systems are connected, the method comprising the steps of: a) measuring a voltage value in each of the plurality of low-voltage distribution systems with a voltage measuring device provided in each of the plurality of low-voltage distribution systems; b) measuring a voltage value in the high-voltage distribution system with a predetermined high-voltage device provided in the high-voltage distribution system; c) measuring a voltage regulator provided in the high-voltage distribution system, a power conditioner provided in the distributed power source, and The method is characterized in that the method repeatedly performs the steps of: calculating operating parameters of each of the static var compensators provided in each of the plurality of low-voltage distribution systems based on the measured values ​​in step a) and step b); and d) operating the voltage regulator, the power conditioner, and the static var compensator based on the operating parameters calculated in step c), thereby maintaining the voltage value in each of the plurality of low-voltage distribution systems within a predetermined control range over time and smoothing the time change of the voltage value within at least a portion of the control range.

[0012] A second aspect of the present invention is a voltage adjustment method in a low-voltage distribution system according to the first aspect, characterized in that in the step d), the time change of the voltage value is smoothed for the entire range of the control width.

[0013] A third aspect of the present invention is a voltage adjustment method in a low-voltage distribution system according to the first aspect, characterized in that in the step d), the time change of the voltage value is smoothed in a range from a lower limit or an upper limit of the control range to a predetermined threshold value.

[0014] A fourth aspect of the present invention is a voltage adjustment method in a low-voltage distribution system according to the first aspect, characterized in that in the step d), the voltage value is kept constant at a predetermined target value within the range of the control range.

[0015] A fifth aspect of the present invention is a voltage adjustment method in a low-voltage distribution system according to the fourth aspect, characterized in that in the step d), a lower limit value of the control range or a value close to the lower limit value is set as the predetermined target value.

[0016] A sixth aspect of the present invention is a method for adjusting voltages in a plurality of low-voltage distribution systems of a distribution system including a plurality of low-voltage distribution systems, each of which is connected to a distributed power source, and a high-voltage distribution system formed by connecting the plurality of low-voltage distribution systems, the method comprising the steps of: a) measuring a voltage value in each of the plurality of low-voltage distribution systems with a voltage measuring device provided in each of the plurality of low-voltage distribution systems; b) measuring the voltage value in the high-voltage distribution system with a predetermined high-voltage device provided in the high-voltage distribution system; c) measuring the respective operating parameters of a voltage regulator provided in the high-voltage distribution system and a power conditioner provided in the distributed power source by using the steps a) and The present invention is characterized in that by repeatedly performing in parallel a set of a step of calculating based on the measured values ​​in step b) and a step of d) operating the voltage regulator and the power conditioner based on the operating parameters calculated in step c), and a step of e) operating a static var compensator provided in each of the plurality of low-voltage distribution systems based on predetermined fixed operating parameters, the voltage value in each of the plurality of low-voltage distribution systems is maintained over time within a predetermined control range, while smoothing the time change of the voltage value within at least a portion of the control range.

[0017] A seventh aspect of the present invention is a voltage adjustment method in a low-voltage distribution system according to any of the first to sixth aspects, characterized in that in the step c), operating parameters of the voltage regulator are calculated so that the voltage regulator operates in the step d) to compress the fluctuation range of the voltage value in a waveform showing the time change of the voltage value, and operating parameters of the power conditioner are calculated so that the power conditioner operates in the step d) to shift the waveform in a direction toward the lower limit or upper limit of the control range.

[0018] An eighth aspect of the present invention is a voltage adjustment method in a low-voltage distribution system according to the seventh aspect, characterized in that in the step c), operating parameters of the power conditioner are calculated so that the waveform shifts in a direction toward a lower limit value of the control range as a result of the power conditioner operating in the step d).

[0019] A ninth aspect of the present invention is a voltage adjustment method in a low-voltage distribution system relating to any of the first to sixth aspects, characterized in that in the step a), a smart meter provided in each of the plurality of low-voltage distribution systems is used as the voltage adjustment device.

[0020] A tenth aspect of the present invention is a power system including a plurality of low voltage distribution systems, each connected to a distributed power source, and a high voltage distribution system to which the plurality of low voltage distribution systems are connected, the power system including a voltage measuring device provided in each of the plurality of low voltage distribution systems and capable of measuring a voltage value in each of the plurality of low voltage distribution systems, a predetermined high voltage device provided in the high voltage distribution system and capable of measuring a voltage value in the high voltage distribution system, a voltage regulator provided in the high voltage distribution system, a power conditioner provided in the distributed power source, a static var compensator provided in each of the plurality of low voltage distribution systems, and a control circuit for controlling the operation of the power system. and a controller, wherein the controller calculates operating parameters of the voltage regulator, the power conditioner, and the static var compensator based on measured values ​​of the voltage measuring device and the specified high-voltage equipment, and operates the voltage regulator, the power conditioner, and the static var compensator based on the calculated operating parameters, thereby maintaining the voltage value in each of the multiple low-voltage distribution systems within a specified control range over time and smoothing the time change of the voltage value within at least a portion of the control range.

[0021] An eleventh aspect of the present invention is a power system according to the tenth aspect, characterized in that the controller operates the static var compensator so that the time change of the voltage value is smoothed over the entire range of the control width.

[0022] A twelfth aspect of the present invention is a power system according to the tenth aspect, characterized in that the controller operates the static var compensator so as to smooth the change over time of the voltage value in a range from a lower limit or an upper limit of the control range to a predetermined threshold value.

[0023] A thirteenth aspect of the present invention is a power system according to the tenth aspect, characterized in that the controller operates the static var compensator so that the voltage value becomes constant at a predetermined target value within the range of the management width.

[0024] A fourteenth aspect of the present invention is the power system according to the thirteenth aspect, characterized in that the predetermined target value is a lower limit value of the control range or a value in the vicinity thereof.

[0025] A fifteenth aspect of the present invention is a power system including a plurality of low voltage distribution systems, each connected to a distributed power source, and a high voltage distribution system to which the plurality of low voltage distribution systems are connected, the power system comprising: a voltage measuring device provided in each of the plurality of low voltage distribution systems and capable of measuring a voltage value in each of the plurality of low voltage distribution systems; a predetermined high voltage device provided in the high voltage distribution system and capable of measuring a voltage value in the high voltage distribution system; a voltage regulator provided in the high voltage distribution system; a power conditioner provided in the distributed power source; a static var compensator provided in each of the plurality of low voltage distribution systems; and a controller for controlling operation of the power system; The controller calculates operating parameters of the voltage regulator and the power conditioner based on measured values ​​of the voltage measuring device and the specified high-voltage equipment, and operates the voltage regulator and the power conditioner based on the calculated operating parameters, and operates the static var compensator based on predetermined fixed operating parameters, in parallel and repeatedly, thereby maintaining the voltage value in each of the multiple low-voltage distribution systems over time within a specified control range while smoothing the time-dependent changes in the voltage value within at least a portion of the control range.

[0026] A 16th aspect of the present invention is a power system according to any of the 10th to 15th aspects, characterized in that the controller calculates operating parameters of the voltage regulator so that the operation of the voltage regulator compresses the fluctuation range of the voltage value in a waveform showing the time change of the voltage value, and calculates operating parameters of the power conditioner so that the operation of the power conditioner shifts the waveform in a direction toward the lower limit or upper limit of the control range.

[0027] A 17th aspect of the present invention is a power system according to the 16th aspect, characterized in that the controller calculates operating parameters of the power conditioner so that the waveform shifts toward the lower limit of the control range as a result of the power conditioner operating.

[0028] An 18th aspect of the present invention is a power system relating to any of the 10th to 15th aspects, characterized in that a smart meter is provided in each of the plurality of low-voltage distribution systems, and the smart meter measures a voltage value in each of the plurality of low-voltage distribution systems as the voltage regulating device.

[0029] According to the first to eighteenth aspects of the present invention, the voltage values ​​in all low-voltage distribution systems can be maintained within the control width over time.

[0030] In particular, according to the third and twelfth aspects, it is possible to maintain the voltage values ​​in all low-voltage distribution systems within the control width over time while ensuring a margin in the static var compensator.

[0031] In particular, according to the fifth, eighth, fourteenth, and seventeenth aspects, it is possible to obtain an energy saving effect by CVR (Conservation Voltage Reduction).

[0032] In particular, according to the fifth and fourteenth aspects, the energy saving effect of the CVR can be maximized. [Brief description of the drawings]

[0033] [Figure 1] FIG. 1 is a diagram illustrating a schematic configuration of a power system 1000. [Diagram 2] FIG. 6 is a block diagram showing functional components of a controller 600. [Diagram 3] FIG. 11 is a diagram showing a process flow in a first low pressure adjustment mode. [Figure 4]1 is a diagram showing a voltage profile PF0 indicating a change in voltage value over time in a low-voltage distribution system 2. FIG. [Diagram 5] 13 is a diagram showing a voltage profile PF1 for an average measurement value that the smart meter control unit 622 acquires from the smart meter 203. FIG. [Figure 6] 10 is a diagram for explaining the effect of changing the operating parameters of the high voltage regulator 300 on the voltage profile. FIG. [Figure 7] 11 is a diagram for explaining the effect of changing the operating parameters in the low-voltage PCS 202p on the voltage profile. FIG. [Figure 8] 13 is a diagram showing an actual voltage profile PF4 in the low-voltage distribution system 2 when the high-voltage voltage regulator 300 and the low-voltage PCS 202p are operated according to optimal parameters. FIG. [Figure 9] FIG. 13 is a diagram showing an actual voltage profile PF5 in the low-voltage distribution system 2 when the SVG 204 is operated with optimal parameters. [Figure 10] FIG. 11 is a diagram showing a process flow in a second low pressure adjustment mode. [Figure 11] FIG. 13 is a diagram showing an actual voltage profile PF6 in a low-voltage distribution system 2 when low-voltage regulation is performed in a second low-voltage regulation mode. [Figure 12] FIG. 11 is a diagram showing a process flow in a third low pressure adjustment mode. [Figure 13] FIG. 13 is a diagram showing an actual voltage profile PF7 in a low-voltage distribution system 2 when low-voltage regulation is performed in a third low-voltage regulation mode. [Figure 14] FIG. 13 is a diagram showing a process flow in a fourth low pressure adjustment mode. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] <Outline of the power system> 1 is a diagram showing a schematic configuration of a power system 1000 to which a voltage adjustment method according to an embodiment of the present invention is applied. The power system 1000 is generally a system that transmits and distributes power between a distribution substation (hereinafter also simply referred to as a substation) 100 and a large number of consumers 200 (more specifically, electrical equipment owned by each consumer, the same applies below) by using a high-voltage distribution system 1 and a low-voltage distribution system 2 connected thereto. For example, the voltage in the high-voltage distribution system 1 is 6.6 kV, and the voltage in the low-voltage distribution system 2 is 100 V or 200 V. In another example, the voltage in the high-voltage distribution system 1 is 12 kV, and the voltage in the low-voltage distribution system 2 is 120 V or 240 V.

[0035] The substation 100 is a facility that uses a transformer to step down the voltage of electric power supplied from a power plant (not shown) and transmits the power to a consumer 200. The voltage transmitted from the substation 100 is adjusted by an LRT (Load Ratio control Transformer: on-load tap changing transformer) 101.

[0036] Each consumer 200 has various electrical devices 201 as loads, and these electrical devices 201 are connected to a low-voltage power distribution system 2 prepared for each consumer 200.

[0037] The consumer 200 further owns a distributed power source 202, which is also connected to the low-voltage power distribution system 2. Examples of the distributed power source 202 include a photovoltaic power generation device (PV), an electric vehicle (EV), a fuel cell, and a gas engine.

[0038] However, it is not necessary for all consumers 200 to have the distributed power sources 202 , and there may be consumers 200 that only have electrical equipment 201 connected to the low-voltage distribution system 2 .

[0039] The distributed power source 202 is equipped with a low-voltage PCS (power conditioner) 202p that converts generated power into grid power. The low-voltage PCS 202p controls the operation (power generation) of the distributed power source 202, conversion of DC power generated by the distributed power source 202 into AC power, and connection of the distributed power source 202 to the grid.

[0040] Further, each low-voltage distribution system 2 is provided with a smart meter 203 and a static var generator (SVG) 204 as a low-voltage voltage regulator.

[0041] The smart meter 203 is a device that measures the amount of power usage in each consumer 200. The smart meter 203 is capable of outputting an average measurement value at least every 5 minutes. The smart meter 203 has a communication function, and by using the communication function, each consumer 200 can check its own amount of power usage at any time. As will be described later, in this embodiment, the communication function of the smart meter 203 is also used for voltage adjustment in the power system 1000. Specifically, in the voltage adjustment method according to the embodiment of the present invention, the smart meter 203 provided in each low-voltage distribution system 2 is used as a voltage measurement device that measures a voltage value in the low-voltage distribution system 2.

[0042] The SVG 204 adjusts the voltage fluctuations in each low-voltage distribution system 2. The SVG 204 is generally a device that supplies reactive power to the low-voltage distribution system 2 and adjusts the voltage of the low-voltage distribution system 2 to satisfy specified conditions. The SVG 204 is configured to be capable of continuously and quickly performing a wide range of reactive power compensation, from leading to lagging, by including an inverter.

[0043] Since each low-voltage distribution system 2 includes the SVG 204, it can be said that a large number of SVGs 204 are distributed throughout the power system 1000 according to the present embodiment. Therefore, in the present embodiment, the SVG 204 is also referred to as a distributed SVG.

[0044] On the other hand, the high voltage distribution system 1 is provided with a high voltage regulator 300 and a switch with sensor 400 .

[0045] The high voltage regulator 300 is generally a device that suppresses voltage fluctuations (voltage drops) in the high voltage distribution system 1, and adjusts the voltage fluctuations on the line by automatically selecting (switching) a tap in response to fluctuations in the current flowing through the high voltage distribution system 1. Examples of the high voltage regulator 300 include SVR, TVR, and TSC type SVC.

[0046] 1 is merely an example. The specific location of the high voltage regulator 300 may be determined appropriately depending on the configuration of the power system 1000 (such as the branching manner of the high voltage distribution system 1, the connection manner of the low voltage distribution system, etc.).

[0047] The sensor-equipped switch 400 is a high-voltage device that uses a built-in sensor to measure current, voltage, and the like at the installation point. When a voltage drop occurs due to a power outage or accident in the high-voltage distribution system 1 or the low-voltage distribution system 2, the sensor-equipped switch 400 is designed to isolate the affected area from the system, thereby minimizing the impact of the power outage or accident.

[0048] 1, the sensor-equipped switch 400 is provided at the connection point of each low-voltage distribution system 2 to the high-voltage distribution system 1, but this is merely an example. The low-voltage distribution system 2 may be connected to the high-voltage distribution system 1 without passing through the sensor-equipped switch 400, or the sensor-equipped switch 400 may be provided at an appropriate point along the high-voltage distribution system 1.

[0049] A large-scale photovoltaic power generation system (high-voltage PV) 500, also called a mega solar system, may be further connected to the high-voltage power distribution system 1. The high-voltage PV 500 is equipped with a high-voltage PCS (power conditioner) 500p that converts generated power into grid power. The PCS 500p controls the operation (power generation operation) of the high-voltage PV 500, the conversion of DC power generated by the high-voltage PV 500 to AC power, and the connection of the high-voltage PV 500 to the grid.

[0050] The power system 1000 further includes a controller (control device) 600 that controls the overall operation. The controller 600 is connected to the substation 100 including the LRT 101, the low-voltage PCS 202p and smart meter 203 of each consumer 200, the SVG 204 of each low-voltage distribution system 2, the high-voltage voltage regulator 300, the sensor-equipped switch 400, and the high-voltage PCS 500p through a signal line CL. The controller 600 is capable of transmitting control signals to each device through the signal line CL and receiving signals indicating operation states and signals indicating measurement values ​​from each device. The connection between the controller 600 and each of the above-mentioned devices through the signal line CL may include wireless connection, and may be a connection using not only a dedicated line but also a general-purpose Internet.

[0051] 2 is a block diagram showing functional components of the controller 600. The controller 600 is configured by a general-purpose or dedicated computer, and predetermined functional components are realized by, for example, executing a predetermined program stored in a storage device by a CPU.

[0052] The controller 600 mainly includes, as its functional components, a high-voltage equipment control unit 610, a customer equipment control unit 620, and a data processing unit 630.

[0053] The high voltage equipment control unit 610 is a part that acquires signals indicating the operating status of the LRT 101, high voltage voltage regulator 300, sensor-equipped switch 400, and high voltage PCS 500p that are provided in the high voltage distribution system 1, as well as signals indicating the measurement values ​​of the measurements (monitoring) performed by the sensor-equipped switch 400, and causes each device to operate based on operating parameters that are set and updated by the data processing unit 630 in response to these signals.

[0054] The high voltage equipment control unit 610 includes a first voltage regulator control unit 611 that controls the operation of the LRT 101, a second voltage regulator control unit 612 that controls the operation of the high voltage voltage regulator 300, a sensor-equipped switch control unit 613 that controls the operation of the sensor-equipped switch 400, and a high voltage PCS control unit 314 that controls the operation of the high voltage PCS 500p.

[0055] The consumer equipment control unit 620 acquires signals indicating the operating status of the low-voltage PCS 202p and SVG 204 connected to each of the multiple low-voltage distribution systems 2 prepared for each consumer 200, and signals indicating the measurement values ​​of measurements (monitoring) performed by the smart meter 203, and causes the low-voltage PCS 202p and SVG 204 to operate based on operating parameters set and updated by the data processing unit 630 in response to these signals.

[0056] The consumer equipment control unit 620 includes a low voltage PCS control unit 621 that controls the operation of the low voltage PCS 202p, a smart meter control unit 622 that acquires the measurement values ​​of the smart meter 203, and a distributed SVG control unit 623 that controls the operation of the SVG 204.

[0057] The data processing unit 630 includes a data aggregation unit 631 and a control parameter calculation unit 632. The data aggregation unit 631 aggregates data indicated by operation signals and measurement value signals acquired by each unit of the high-voltage equipment control unit 610 and the consumer equipment control unit 620 from various devices. The control parameter calculation unit 632 calculates operation parameters of the LRT 101, the high-voltage voltage regulator 300, the sensor-equipped switch 400, the high-voltage PCS 500p, the low-voltage PCS 202p, and the SVG 204 based on the data aggregated by the data aggregation unit 631. Each unit of the high-voltage equipment control unit 610 and the consumer equipment control unit 620 causes the devices to be controlled to operate based on the operation parameters calculated by the control parameter calculation unit 632.

[0058] <Voltage regulation in low-voltage distribution systems> Next, voltage regulation (low voltage regulation) in each of the multiple low-voltage distribution systems 2 provided corresponding to each of the consumers 200, which is performed in the power system 1000 having the above-mentioned configuration, will be described.

[0059] In this embodiment, in addition to using a high voltage voltage regulator 300 provided in a high voltage distribution system 1 that has been used for conventional low voltage adjustment, an SVG 204 is provided in each low voltage distribution system 2, and the SVG 204 is used for low voltage adjustment together with a low voltage PCS 202 and a smart meter 203 also connected to each low voltage distribution system 2. In the following, for ease of explanation, the high voltage PV 500 will be treated as being included in the high voltage distribution system 1.

[0060] There are three types of low pressure adjustment in this embodiment, namely, first to third modes, which will be described below in order.

[0061] (First low pressure adjustment mode: basic mode) Fig. 3 is a diagram showing a processing flow in the first low voltage adjustment mode. Fig. 4 is a diagram showing a voltage profile (waveform) PF0 indicating a change in voltage value over time in a low voltage distribution system 2 as an example of a target of voltage adjustment performed in this embodiment. The voltage profile PF0 corresponds to a profile after adjustment in a conventionally known adjustment mode. In other words, the voltage profile PF0 is an example of a change in voltage value over time in a low voltage distribution system 2 when processing in the first low voltage adjustment mode is not performed.

[0062] As shown in FIG. 4, the voltage in each low-voltage distribution system 2 is set to a lower limit of V L The upper limit is V U That is, the controller 600 controls the voltage in each low-voltage distribution system 2 so that the voltage in each low-voltage distribution system 2 falls within the associated management range R. For example, the lower limit value V L is 95V, and the upper limit V U is 107V.

[0063] However, even if the voltage is adjusted in a conventional manner, the voltage constantly fluctuates (in a short cycle) and reaches the upper limit V U Fluctuations exceeding the lower limit V as shown in part B L Also, fluctuations called spikes SP, in which the voltage value rises and falls sharply for an extremely short period of time, can occur randomly.

[0064] In the first low voltage regulation mode, the voltage values ​​in the individual low voltage distribution systems 2 are regulated on the premise that such fluctuations may occur in the voltage profile before regulation.

[0065] Specifically, the smart meter 203 provided in each low-voltage distribution system 2 measures the voltage value in the low-voltage distribution system 2 (step S1), and outputs the average measurement value (moving average value) every 5 minutes to the smart meter control unit 622. In this case, the smart meter 203 functions as a voltage measurement device, and the smart meter control unit 622 functions as a voltage measurement control unit that controls the voltage measurement device.

[0066] In parallel with this, the sensor-equipped switch 400 installed in the high-voltage distribution system 1 measures the voltage of the high-voltage distribution system 1 at its installation location (step S2) and outputs the measured value to the sensor-equipped switch control unit 613.

[0067] Figure 5 is a diagram showing a voltage profile PF1 for average measurement values ​​obtained from the smart meter 203 by the smart meter control unit 622 functioning as a voltage measurement control unit when voltage measurements targeting the voltage profile PF0 shown in Figure 4 are performed by the smart meter 203 functioning as a voltage measurement device.

[0068] To be sure, the time on the horizontal axis of the voltage profile PF0 shown in Fig. 4 is sufficiently longer than the measurement interval by the smart meter 203, and therefore the measurement by the smart meter 203 is not performed at a timing when the entire voltage profile PF0 shown in Fig. 4 is obtained, but is performed in real time in a situation where the voltage value of the low-voltage distribution system 2 fluctuates as shown in the voltage profile PF0. In other words, the time change of the voltage value in the voltage profile PF0 shown in Fig. 4 and the time change of the average measurement value in the voltage profile PF1 shown in Fig. 5 proceed simultaneously in parallel.

[0069] The voltage profile PF1 is a smoothed version of the voltage profile PF0 shown in FIG. 4, but as shown in part C, the voltage value is the upper limit V UThere are still some points exceeding this value, and some spikes SP remain. Note that although the controller 600 acquires the voltage profile PF1, the voltage profile PF0 in the actual low-voltage distribution system 2 has not been smoothed, and still exhibits the behavior shown in FIG.

[0070] The data of average measurement values ​​in each low-voltage distribution system 2 acquired by the smart meter control unit 622 and the voltage data in the high-voltage distribution system 1 acquired by the sensor-equipped switch control unit 613 are aggregated by the data aggregation unit 631 of the controller 600 (step S3). In addition, the data aggregation unit 631 also constantly aggregates data based on operation signals acquired from various devices by each unit of the high-voltage equipment control unit 610 and the consumer equipment control unit 620.

[0071] Next, based on the various data aggregated in the data aggregation unit 631, the control parameter calculation unit 632 calculates optimal values ​​(optimum parameters) for the operating parameters of the high voltage voltage regulator 300, the low voltage PCS 202p, and the low voltage voltage regulator SVG 204 when performing low voltage adjustment of the low voltage distribution system 2 (step S4).

[0072] Examples of the operating parameters of the high voltage regulator 300 include a target voltage and a dead band range. Examples of the operating parameters of the low voltage PCS 202p include a power factor and a VP characteristic. Examples of the operating parameters of the SVG 204 include a target voltage, a dead band width, and a response speed.

[0073] When the optimal parameters are calculated in the control parameter calculation unit 632, the second voltage regulator control unit 612 applies the optimal parameters to the high voltage regulator 300, that is, changes the parameters (step S5), and the low voltage PCS control unit 621 applies the optimal parameters to the low voltage PCS 202p, that is, changes the parameters (step S6). Note that, although these parameter changes are performed in parallel in Fig. 3, the former may be performed first and then the latter may be performed.

[0074] The optimal parameters of high voltage voltage regulator 300 are calculated so that, as a result of operation of high voltage voltage regulator 300 based on the optimal parameters, a state is realized in which voltage fluctuations in low voltage distribution system 2 fall within a predetermined allowable fluctuation range R1 that is compressed more than the control range R shown in FIG. 4 or FIG. 5.

[0075] 6 is a diagram for explaining the effect that a change in the operating parameters of the high voltage regulator 300 has on the voltage profile. In the following, as shown in FIG. 6, the lower limit of the allowable fluctuation range R1 is set to V1, and the upper limit (target upper limit voltage) is set to V2. Also, the median value of the allowable fluctuation range R1 (the average value of the lower limit V1 and the upper limit V2) is set to V1, and the median value of the control range R (the lower limit V L and the upper limit V U In other words, the median value of the control range R is set as the target voltage, and the range of the allowable fluctuation range R1 from the lower limit V1 to the upper limit V2 is set as the dead band.

[0076] In general terms, when the high voltage regulator 300 operates according to optimal parameters, the voltage value in the low voltage distribution system 2 is, in principle, compressed in accordance with the ratio R1 / R of the allowable fluctuation range R1 to the control range R while maintaining the median value.

[0077] However, if the voltage value after compression still does not fall within the range of the allowable fluctuation range R1, which is the dead band, the voltage value is shifted in a stepwise manner into the range of the allowable fluctuation range R1 by tap switching in the high voltage voltage regulator 300. As a result, the voltage value in the low voltage distribution system 2 always falls within the range of the allowable fluctuation range R1.

[0078] The voltage profile PF2 shown in Fig. 6 is an example of a voltage profile for an average measurement value that the smart meter control unit 622 acquires from the smart meter 203 when the operating parameters of the high voltage voltage regulator 300 are changed. More specifically, it is an example when the voltage profile PF0 shown in Fig. 4 indicates the fluctuation of the voltage value in the low voltage distribution system 2 when the operating parameters of the high voltage voltage regulator 300 are not changed. Alternatively, it can be said that the voltage profile PF1 shown in Fig. 5 is an example when it is assumed to be a voltage profile for an average measurement value that the smart meter control unit 622 acquires from the smart meter 203 when the operating parameters of the high voltage voltage regulator 300 are not changed.

[0079] 6, the voltage after compression in portion D1 reaches the upper limit V2 of the allowable fluctuation range R1, so the voltage is reduced in a stepwise manner. Similarly, the voltage after compression in portion D2 reaches the lower limit V1 of the allowable fluctuation range R1, so the voltage is increased in a stepwise manner.

[0080] Furthermore, spikes SP still exist in voltage profile PF2. Moreover, some of the spikes SP deviate from the range of allowable fluctuation width R1. This is because the sudden voltage change in the spikes SP is on the order of milliseconds, whereas the response time of high-voltage voltage regulator 300 is on the order of seconds to minutes, and therefore the tap switching of high-voltage voltage regulator 300 cannot keep up with the sudden fluctuation of the spikes SP.

[0081] However, the voltage profile PF2 shown in Figure 6 is, overall, L to the upper limit V U It is within the range of the control width R.

[0082] Next, the optimal parameters of the low voltage PCS 202p are calculated so that a state in which the voltage value shifts by a predetermined value within the range of the control width R is realized as a result of the low voltage PCS 202p operating based on the optimal parameters.

[0083] Fig. 7 is a diagram for explaining the influence of the change in the operating parameters in the low-voltage PCS 202p on the voltage profile. For ease of understanding, Fig. 7 shows a case where the operating parameters in the low-voltage PCS 202p are changed after the voltage fluctuation is compressed by the operation of the high-voltage voltage regulator 300.

[0084] In general terms, when the low-voltage PCS 202p operates according to the optimal parameters, the voltage value in the low-voltage power distribution system 2 is shifted by a certain amount within the range of the control range R while maintaining the allowable fluctuation range R1. In this embodiment, the lower limit V1 of the allowable fluctuation range R1 is set to the lower limit V of the control range R with the intention of voltage management by CVR (Conservation Voltage Reduction). L In this case, the lower limit V of the control range R is shifted to a value close to L For example, a value close to 1.01×V L In the case of Japan, the lower limit of the control range R in a 100V low-voltage distribution system is V L Since the lower limit V1 of the allowable fluctuation range R1 is 95V, the lower limit V1 of the allowable fluctuation range R1 may be set to, for example, 96V. L Since the upper limit V2 of the allowable fluctuation range R1 is 182V, the lower limit V1 of the allowable fluctuation range R1 may be set to, for example, 184V. In this way, the power consumption of the consumer 200 is reduced as the voltage value in the low-voltage distribution system 2 is reduced, thereby achieving an energy saving effect. U It is also possible to shift the value to a value close to .

[0085] 7 is an example of a voltage profile for an average measurement value that the smart meter control unit 622 acquires from the smart meter 203 when the operating parameters are changed in the low-voltage PCS 202p. More specifically, the voltage profile PF3 is an example of a voltage profile for an average measurement value that the smart meter control unit 622 acquires from the smart meter 203 when the operating parameters are changed in the low-voltage PCS 202p. LThis is an example of the case where a shift has been made so as to substantially match with the voltage profile PF0 shown in Fig. 4. Similarly to the voltage profile PF2 shown in Fig. 6, this is also an example of the case where the voltage profile PF0 shown in Fig. 4 indicates fluctuations in the voltage value in the low-voltage power distribution system 2 when the operating parameters of the high-voltage voltage regulator 300 are not changed. Note that the upper limit value of the allowable fluctuation range R1 after such a shift is set to V3.

[0086] Although the voltage values ​​are different, the overall shape of the voltage profile PF3 shown in Fig. 7 is the same as the voltage profile PF2 shown in Fig. 6. Therefore, although spikes SP still exist, the shift in the allowable fluctuation range R1 is only performed within the range of the control range R, so the voltage profile PF3 shown in Fig. 7 generally falls within the range of the control range R.

[0087] Therefore, at first glance, it may seem that voltage management by CVR within the range of the management width R can be performed appropriately if the high voltage regulator 300 and the low voltage PCS 202p are operated according to optimal parameters.

[0088] However, the voltage profile PF3 shown in Fig. 7 is merely a profile of the average measurement value every 5 minutes by the smart meter 203. Fig. 8 is a diagram showing an actual voltage profile PF4 in the low-voltage distribution system 2 when the high-voltage voltage regulator 300 and the low-voltage PCS 202p, which are the basis of the voltage profile PF3 shown in Fig. 7, are operated according to optimal parameters.

[0089] As shown in the voltage profile PF0 in FIG. 4, the actual voltage in the low-voltage distribution system 2 has small short-period fluctuations. Therefore, in the actual voltage profile PF4, as shown in part E in FIG. 8, the voltage value falls within the lower limit V, which is within the range of the control width R in the voltage profile PF3 shown in FIG. 7. L There is a deviation outside the range of the control range R in the vicinity of

[0090] In other words, in order to perform voltage management by CVR only by operating the high voltage regulator 300 and the low voltage PCS 202p according to the optimal parameters, the shift position of the allowable fluctuation range R1 and the lower limit V of the management range R must be set in consideration of the possibility of such deviations occurring. L This means that a certain margin needs to be secured between the customer and the CVR. However, securing such a margin naturally reduces the effect of CVR.

[0091] In the first low voltage regulation mode performed in this embodiment, in consideration of this point, high voltage voltage regulator 300 and low voltage PCS 202p are operated with optimal parameters, and then SVGs 204 (distributed SVGs) provided in each low voltage distribution system 2 are operated with optimal parameters calculated by control parameter calculation unit 632, thereby smoothing out small short-term fluctuations in the actual voltage value, such as those appearing in voltage profile PF4 shown in FIG. 8 (step S7).

[0092] Fig. 9 is a diagram showing an actual voltage profile PF5 in the low-voltage distribution system 2 when the SVG 204 is operated with optimal parameters. More specifically, this is an actual voltage profile obtained when the SVG 204 is operated with optimal parameters in a situation in which voltage fluctuation occurs according to the voltage profile PF4 shown in Fig. 8 when the SVG 204 is not operated with optimal parameters.

[0093] The SVG 204 is equipped with an inverter and operates at high speed, making it possible to smooth out short-period fluctuations in the voltage value of the low-voltage distribution system 2 and to remove or reduce spikes SP.

[0094] Therefore, the voltage profile PF5 in Fig. 9 obtained as a result of the operation of the SVG 204 is approximately consistent with the voltage profile PF3, which is the voltage profile for the average measurement value acquired by the smart meter control unit 622 from the smart meter 203 when the high voltage voltage regulator 300 and the low voltage PCS 202p are operated with optimal parameters as shown in Fig. 7. Moreover, while spikes SP existed in the voltage profile PF3, the spikes SP are suitably removed in the voltage profile PF5.

[0095] This means that even if the controller 600 only knows a voltage profile for an average measurement value every five minutes from the smart meter 203, such as voltage profile PF3, if the SVG 204 is operated with optimal parameters, the voltage profile for the average measurement value can be treated as being essentially a voltage profile for an actual voltage value.

[0096] Furthermore, the fact that the actual voltage value intensity is like the voltage profile PF5 means that in order to maximize the effect of the CVR, when operating the low-voltage PCS202p with optimal parameters, the lower limit V1 of the allowable fluctuation range R1 is set to the lower limit V L This means that a shift can be made so as to approximately match the

[0097] The process from step S1 to step S7 is repeated in all low-voltage distribution systems 2 of the power system 1000. That is, the data aggregation unit 631 of the controller 600 aggregates data of average measurement values ​​in each low-voltage distribution system 2 and data of voltage in the high-voltage distribution system 1, and the control parameter calculation unit 632 calculates optimal parameters of the high-voltage voltage regulator 300, the low-voltage PCS 202p, and the SVG 204 provided in each low-voltage distribution system 2 based on the aggregated data, and the high-voltage voltage regulator 300, the low-voltage PCS 202p, and the SVG 204 operate based on the calculated optimal parameters in a real-time loop. That is, each time the process is looped, the optimal parameters are updated to the latest ones.

[0098] This makes it possible to prevent the occurrence of fluctuations in voltage values ​​that deviate from the control range R as exemplified by the voltage profile PF0 shown in Fig. 4 in all low-voltage distribution systems 2 included in the power system 1000. In other words, it is possible to keep the voltage values ​​in all low-voltage distribution systems 2 within the control range over time.

[0099] This means that the first low voltage regulation aspect realizes highly accurate and less fluctuating voltage management of a low voltage distribution system.

[0100] Moreover, in each low-voltage distribution system 2, for example, as in the voltage profile PF5 shown in FIG. 9, the range in which the voltage value fluctuates is the lower limit V L By shifting the frequency to the vicinity of 0.5 V, it is possible to obtain the effect of CVR in a favorable manner.

[0101] Furthermore, by operating the SVG 204, the actual voltage profile in the low-voltage distribution system 2 is smoothed in real time like the voltage profile PF5 shown in Fig. 9, and the actual voltage profile becomes similar to the profile of the average measurement value every 5 minutes acquired by the controller 600 from the smart meter 203, like the voltage profile PF3 shown in Fig. 7. Therefore, even if the controller 600 only acquires the average measurement value from the smart meter 203, the acquired value can be regarded as an actual voltage value and handled.

[0102] Since the processes from step S1 to step S7 are repeated, the operation of the SVG 204 using the latest optimal parameters in step S7 does not necessarily have to be performed after steps S5 and S6.

[0103] (Second low pressure regulation mode: conditional operation) In the first low voltage regulation mode described above, each time the processing shown in steps S1 to S7 is repeated, SVG204 operates continuously, and short-period fluctuations and spikes SP that occur in the voltage value of the low-voltage distribution system 2 are suitably suppressed.

[0104] However, the lower limit V of the control range R L While short-term fluctuations in the vicinity of are problematic in that the voltage value deviates from the control range R, the lower limit V L For short-term fluctuations occurring in a range far from the limit, the upper limit V3 of the allowable fluctuation range R1 is set to the upper limit V U Therefore, in this range, even if the smoothing by SVG204 is omitted, it is considered that no particular problem will occur.

[0105] In the second low-voltage regulation mode, low-voltage regulation is performed taking this point into consideration. In summary, in the second low-voltage regulation mode, the range of voltage values ​​for operating the SVG 204 is set to a value within a predetermined threshold value V tThe voltage value of the low-voltage distribution system 2 is limited to the lower limit V L (above) the threshold V t SVG 204 is said to be at an operational level if:

[0106] Fig. 10 is a diagram showing a process flow in the second low voltage regulation mode. Fig. 11 is a diagram showing an actual voltage profile PF6 in the low voltage distribution system 2 when low voltage regulation is performed in the second low voltage regulation mode. More specifically, this is an actual voltage profile obtained by operating the SVG 204 with optimal parameters only when the voltage value in the low voltage distribution system 2 is at the operation level of the SVG 204 in a situation in which voltage fluctuation occurs according to the voltage profile PF4 shown in Fig. 8 when the SVG 204 is not operated at all.

[0107] Steps S1 to S6 in Fig. 10 are the same as the first low voltage adjustment mode shown in Fig. 3. However, the subsequent processing is classified according to whether the voltage value of the low voltage distribution system 2 is at the operation level of the SVG 204 or not (step S8).

[0108] If the voltage value of the low-voltage distribution system 2 is within the operation level of the SVG 204 (YES in step S8), the SVG 204 operates with optimal parameters (step S7) as in the first low-voltage regulation mode. On the other hand, if the voltage value of the low-voltage distribution system 2 is not within the operation level of the SVG 204 (NO in step S8), the SVG 204 does not operate. This is because, for example, the voltage value to be processed is lower than the threshold value V t This can be achieved by presetting the operating conditions of SVG204 so that it will only operate in the following cases.

[0109] When the second low-voltage regulation mode is adopted, the voltage value is adjusted to be lower than the threshold value V t Only when the voltage is below the threshold V t The fluctuation of the voltage value in the range exceeding this is the same as that of the voltage profile PF4 shown in FIG.

[0110] In the second low voltage regulation mode, the process from step S1 to step S7 is repeated. Therefore, in the second low voltage regulation mode, as in the first low voltage regulation mode, it is possible to prevent the occurrence of fluctuations in voltage values ​​that deviate from the management range R in all low voltage distribution systems 2 included in the power system 1000. That is, it is possible to maintain the voltage values ​​in all low voltage distribution systems 2 within the management range over time.

[0111] This means that even when the second low pressure adjustment mode is adopted, the lower limit V L Or the upper limit V U In relation to this, this means that highly accurate and low-fluctuation voltage management of low-voltage distribution systems can be realized.

[0112] Moreover, in each low-voltage distribution system 2, the range in which the voltage value fluctuates is the lower limit V L By shifting the frequency to the vicinity of 0.5 V, it is possible to obtain the effect of CVR in a favorable manner.

[0113] Furthermore, unlike the first low pressure regulation mode in which the SVG 204 operates constantly, in the second low pressure regulation mode the SVG 204 operates only when a predetermined operating level is met, so that the SVG 204 has a certain amount of reserve capacity.

[0114] Since the processes from step S1 to step S8 are repeated, the combination of the judgment in step S8 and the operation of the SVG 204 using the latest optimal parameters in step S7 does not necessarily have to be performed after steps S5 and S6.

[0115] In addition, the range in which the voltage value fluctuates is the upper limit V of the control range R. U When the voltage value of the low-voltage distribution system 2 is shifted to the vicinity of a predetermined threshold value or more (and the upper limit value V of the control range R is U SVG 204 may be at an operational level if

[0116] (Third low voltage regulation mode: voltage constant) In the above-mentioned first and second low voltage regulation modes, the SVG 204 operates to suppress short-period fluctuations and spikes SP occurring in the voltage value of the low voltage distribution system 2. In addition, the effect of the CVR is preferably obtained. Meanwhile, long-period fluctuations (fluctuations) in the voltage value within the range of the control width R are basically permitted.

[0117] However, in order to maximize the effect of the CVR, it is desirable that the voltage value of the low-voltage distribution system 2 be as small as possible within the range of the control width R.

[0118] In the third low voltage regulation mode, low voltage regulation is performed taking this point into consideration. Fig. 12 is a diagram showing a process flow in the third low voltage regulation mode. Fig. 13 is a diagram showing an actual voltage profile PF7 in the low voltage distribution system 2 when low voltage regulation is performed in the third low voltage regulation mode. More specifically, this is an actual voltage profile obtained by operating the SVG204 with optimal parameters according to the third constant voltage regulation mode in a situation where voltage fluctuation occurs in the voltage profile PF4 shown in Fig. 8 when the SVG204 is not operated at all.

[0119] Steps S1 to S7 in Fig. 12 are the same as those in the first low voltage regulation mode shown in Fig. 3. However, in the third low voltage regulation mode, in addition to this, the voltage value in the low voltage distribution system 2 is adjusted to the lower limit value V L In this case, the SVG 204 operates so as to keep the lower limit V of the control range R constant at a target value equal to or close to the lower limit V of the control range R (step S9). L For example, a value close to 1.01×V L The optimal parameters for the SVG 204 in step S9 are different from the optimal parameters in step S7.

[0120] In the third low-voltage adjustment mode, in addition to being able to obtain the same effect as the first low-voltage adjustment mode, voltage management using CVR can be performed more effectively than in the first and second low-voltage adjustment modes, and a more significant energy saving effect can be obtained.

[0121] Since the processes from step S1 to step S7 and step S9 are repeated, the set of operations of the SVG 204 based on the latest optimal parameters in step S7 and step S9 does not necessarily have to be performed after step S5 and step S6.

[0122] (Fourth Low-Voltage Regulation Mode: Operation of Distributed SVG with Fixed Parameters) In the first to third low voltage adjustment modes described above, SVG 204 operates based on optimal parameters calculated by control parameter calculation unit 632. In the fourth low voltage adjustment mode, instead, SVG 204 operates according to operating parameters (fixed parameters) that are previously set as fixed parameters and held in controller 600. As described above, SVG 204 is a device that performs the process of smoothing small short-cycle fluctuations in the actual voltage value, and therefore, as long as the operating parameters are set so as to suitably suppress such smoothing, its operation does not necessarily have to be performed after high voltage regulator 300 and low voltage PCS 202p, which have a longer response time than SVG 204, operate.

[0123] 14 is a diagram showing the process flow in the fourth low pressure adjustment mode, which takes this point into consideration. Steps S1 to S6 in FIG. 14 are the same as those in the first low pressure adjustment mode shown in FIG.

[0124] However, in the first low voltage adjustment mode, the optimum parameters calculated in step S4 include individual SVGs 204 (distributed SVGs), whereas in the fourth low voltage adjustment mode, optimum parameters are calculated only for high voltage regulator 300 and low voltage PCS 202p.

[0125] Furthermore, in the first low voltage regulation mode, following steps S5 and S6, the SVG 204 provided in each low voltage distribution system 2 is operated with optimal parameters calculated by the control parameter calculation unit 632 to smooth out small short-cycle fluctuations in the actual voltage value. In the fourth low voltage regulation mode, instead, in parallel with the processing of steps S1 to S6, the SVG 204 provided in each low voltage distribution system 2 is operated with operating parameters that are fixedly set in advance to smooth out small short-cycle fluctuations that appear in the actual voltage value in each low voltage distribution system 2 (step S7β).

[0126] The processes of steps S1 to S6 and the process of step S7β performed in parallel therewith are repeated in all low-voltage distribution systems 2 of power system 1000. That is, SVG 204 repeatedly operates according to fixed parameters, while high-voltage voltage regulator 300 and low-voltage PCS 202p operate based on the latest optimal parameters calculated each time.

[0127] In the case of the fourth low voltage regulation mode, a voltage profile similar to the voltage profile PF5 in the first low voltage regulation mode shown in Fig. 9 is also realized in each low voltage distribution system 2. That is, high-precision and low-fluctuation voltage management of the low voltage distribution system is realized.

[0128] <Modification> In the voltage adjustment method according to the embodiment described above, the smart meter 203 provided in each low-voltage distribution system 2 in the power system 1000 is used as a voltage measurement device that measures a voltage value in the low-voltage distribution system 2, but instead of using such a smart meter 203, a voltage measurement device that measures a voltage value in the low-voltage distribution system 2 may be provided in each low-voltage distribution system 2, and the measurement value of the voltage measurement device may be used for voltage adjustment in the power system 1000. In such a case, some or all of the individual low-voltage distribution systems 2 may not be provided with a smart meter 203.

Claims

1. A method for adjusting voltages in a power distribution system including a plurality of low-voltage power distribution systems, each of which is connected to a distributed power source, and a high-voltage power distribution system to which the plurality of low-voltage power distribution systems are connected, comprising: a) measuring a voltage value in each of the plurality of low-voltage distribution systems by a voltage measuring device provided in each of the plurality of low-voltage distribution systems; b) measuring a voltage value in the high-voltage distribution system by a predetermined high-voltage device provided in the high-voltage distribution system; c) calculating operation parameters of a voltage regulator provided in the high-voltage distribution system, a power conditioner provided in the distributed power source, and a static var compensator provided in each of the plurality of low-voltage distribution systems based on the measured values ​​in the steps a) and b); d) operating the voltage regulator, the power conditioner, and the static var compensator based on the operating parameters calculated in step c) to maintain a voltage value in each of the plurality of low-voltage distribution systems within a predetermined control range over time, while smoothing a change in the voltage value over time within at least a portion of the control range; A method for regulating voltage in a low-voltage distribution system, comprising:

2. A method for regulating voltage in a low-voltage distribution system according to claim 1, comprising: In the step d), the time variation of the voltage value is smoothed over the entire range of the control width. A method for regulating voltage in a low-voltage distribution system.

3. A method for regulating voltage in a low-voltage distribution system according to claim 1, comprising: In the step d), a time change of the voltage value is smoothed in a range from a lower limit or an upper limit of the control range to a predetermined threshold value. A method for regulating voltage in a low-voltage distribution system.

4. A method for regulating voltage in a low-voltage distribution system according to claim 1, comprising: In the step d), the voltage value is kept constant at a predetermined target value within the range of the control width. A method for regulating voltage in a low-voltage distribution system.

5. A method for regulating voltage in a low-voltage distribution system according to claim 4, comprising the steps of: In the step d), the lower limit of the control range or a value close to the lower limit is set as the predetermined target value. A method for regulating voltage in a low-voltage distribution system.

6. A method for adjusting voltages in a plurality of low-voltage distribution systems of a distribution system including a plurality of low-voltage distribution systems, each of which is connected to a distributed power source, and a high-voltage distribution system in which the plurality of low-voltage distribution systems are connected, comprising: a) measuring a voltage value in each of the plurality of low-voltage distribution systems by a voltage measuring device provided in each of the plurality of low-voltage distribution systems; b) measuring a voltage value in the high-voltage distribution system by a predetermined high-voltage device provided in the high-voltage distribution system; c) calculating operating parameters of a voltage regulator provided in the high-voltage distribution system and a power conditioner provided in the distributed power source based on the measured values ​​in the steps a) and b); and, d) operating the voltage regulator and the power conditioner based on the operating parameters calculated in step c); With e) operating a static var compensator provided in each of the plurality of low-voltage distribution systems based on predetermined fixed operating parameters. and (b) performing the steps of: (a) maintaining a voltage value in each of the plurality of low-voltage distribution systems within a predetermined control range over time; and (b) smoothing a time change in the voltage value within at least a part of the control range. A method for regulating voltage in a low-voltage power distribution system, comprising:

7. A method for regulating voltage in a low-voltage distribution system according to any one of claims 1 to 6, comprising: In the step c), Calculating operating parameters of the voltage regulator in step d) so that the voltage regulator operates to reduce a fluctuation range of the voltage value in a waveform showing a time change of the voltage value; In the step d), an operating parameter of the power conditioner is calculated so that the waveform shifts toward the lower limit or upper limit of the control range by operating the power conditioner; A method for regulating voltage in a low-voltage distribution system.

8. A method for regulating voltage in a low-voltage distribution system according to claim 7, comprising the steps of: In the step c), an operating parameter of the power conditioner is calculated so that the waveform shifts in a direction toward the lower limit of the control range by operating the power conditioner in the step d). A method for regulating voltage in a low-voltage distribution system.

9. A method for regulating voltage in a low-voltage distribution system according to any one of claims 1 to 6, comprising: In the step a), a smart meter provided in each of the plurality of low-voltage distribution systems is used as the voltage adjustment device. A method for regulating voltage in a low-voltage distribution system.

10. A power system including a plurality of low-voltage distribution systems, each of which is connected to a distributed power source, and a high-voltage distribution system to which the plurality of low-voltage distribution systems are connected, a voltage measuring device provided in each of the plurality of low-voltage distribution systems and capable of measuring a voltage value in each of the plurality of low-voltage distribution systems; a predetermined high voltage device provided in the high voltage distribution system and capable of measuring a voltage value in the high voltage distribution system; A voltage regulator provided in the high voltage distribution system; A power conditioner provided in the distributed power source; a static var compensator provided in each of the plurality of low-voltage distribution systems; A controller for controlling an operation of the power system; Equipped with The controller: Calculating operation parameters of the voltage regulator, the power conditioner, and the static var compensator based on the measured values ​​of the voltage measuring device and the predetermined high voltage equipment; By operating the voltage regulator, the power conditioner, and the static var compensator based on the calculated operating parameters, the voltage value in each of the plurality of low-voltage distribution systems is maintained over time within a predetermined control range, and the time variation of the voltage value is smoothed within at least a portion of the control range. This power system is characterized by the above-mentioned.

11. 11. The power system of claim 10, the controller operates the static var compensator so that a time change in the voltage value is smoothed over the entire range of the control width.

1. A power system comprising:

12. 11. The power system of claim 10, the controller operates the static var compensator so that a time change in the voltage value is smoothed within a range from a lower limit or an upper limit of the control range to a predetermined threshold value; 1. A power system comprising:

13. 11. The power system of claim 10, The controller operates the static var compensator so that the voltage value is constant at a predetermined target value within the range of the control width.

1. A power system comprising:

14. 14. The power system of claim 13, the predetermined target value is a lower limit value of the control range or a value in the vicinity thereof; 1. A power system comprising:

15. A power system including a plurality of low-voltage distribution systems, each of which is connected to a distributed power source, and a high-voltage distribution system to which the plurality of low-voltage distribution systems are connected, a voltage measuring device provided in each of the plurality of low-voltage distribution systems and capable of measuring a voltage value in each of the plurality of low-voltage distribution systems; a predetermined high voltage device provided in the high voltage distribution system and capable of measuring a voltage value in the high voltage distribution system; A voltage regulator provided in the high voltage distribution system; A power conditioner provided in the distributed power source; a static var compensator provided in each of the plurality of low-voltage distribution systems; A controller for controlling an operation of the power system; Equipped with The controller: calculating operation parameters of the voltage regulator and the power conditioner based on the measured values ​​of the voltage measuring device and the predetermined high voltage equipment, and operating the voltage regulator and the power conditioner based on the calculated operation parameters; and, operating the static var compensator based on predetermined fixed operating parameters; and (b) performing the steps of: (a) maintaining a voltage value in each of the plurality of low-voltage distribution systems within a predetermined control range over time; and (b) smoothing a time change in the voltage value within at least a part of the control range.

1. A power system comprising:

16. 16. The power system according to claim 10, The controller: calculating an operating parameter of the voltage regulator such that a fluctuation range of the voltage value in a waveform showing a time change of the voltage value is compressed by operating the voltage regulator; Calculating an operating parameter of the power conditioner so that the waveform shifts toward the lower limit or upper limit of the control range by operating the power conditioner; 1. A power system comprising:

17. 17. The power system of claim 16, The controller calculates an operating parameter of the power conditioner so that the waveform shifts toward the lower limit of the management range by operating the power conditioner.

1. A power system comprising:

18. 16. The power system according to claim 10, A smart meter is provided in each of the plurality of low-voltage distribution systems, The smart meter measures a voltage value in each of the plurality of low-voltage distribution systems as the voltage regulator.

1. A power system comprising:

Images