JP2019110719A - System imbalance reduction device and system imbalance reduction method - Google Patents

Abstract

SOLUTION: A system imbalance reduction device comprises, in a power system to which a load is connected: a time determination unit that determines a first time at which a voltage imbalance rate of the power system indicates a prescribed value on a prescribed day; a load determination unit that determines a first change tendency approximate to a second change tendency indicating a temporal change of the voltage imbalance rate of the power system from the plurality of first change tendencies indicating the temporal change of a power consumed by the plurality of loads connected to a first connection phase of the power system on the prescribed date, and determines a first load corresponding to the first change tendency determined; and a load determination unit that selects a load which consumes power nearly equal to a movement power indicating consumption power to be switched to a second connection phase different from the first connection phase from the first connection phase of the first load at the first time.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a system unbalance reducing device and a system unbalance reducing method.

  DESCRIPTION OF RELATED ART Conventionally, the apparatus which determines the connection phase in a distribution line as disclosed, for example in patent document 1 is known. In the device disclosed in Patent Document 1, based on the characteristic knowledge obtained by analyzing the load connected to each phase and the voltage unbalance due to the solar power generation facility, the maximum time of unbalance and each line The connection phase is determined based on the combination of the high and low characteristics of the voltage.

Unexamined-Japanese-Patent No. 2017-5893

  However, in the device described in Patent Document 1, the connection phase of the pole transformer is selected so that the load is shared by the light load phase based on the level characteristic of the voltage between lines. There is a possibility that the voltage imbalance can not be corrected properly because the load trend that changes accordingly is not properly reflected.

The main present invention for solving the above-mentioned problems is a time specifying unit for specifying a first time in which a voltage unbalance rate of the power system shows a predetermined value on a predetermined day in a power system to which a load is connected; Among the plurality of first change trends indicating the time change of the power consumed by the plurality of loads connected to the first connection phase of the power system on the predetermined day, the time of the voltage unbalance ratio of the power system A load identification unit that identifies the first change trend that approximates a second change trend that indicates a change, and identifies a first load that corresponds to the identified first change trend; and the first time at the first time A load selection unit for selecting a load which consumes substantially the same power as mobile power indicating power consumption to be switched from the first connection phase to a second connection phase different from the first connection phase among one load; Prepare.
Other features of the present invention will be apparent from the accompanying drawings and the description herein.

  According to the present invention, it is possible to easily identify a load capable of reducing the voltage unbalance rate of the power system by extracting the time change of the power consumption of the load approximating the time change of the voltage unbalance rate. Management work becomes easy.

It is a schematic diagram showing an example of the electric power system concerning a 1st embodiment. It is a block diagram which shows an example of the system unbalance reduction apparatus which concerns on 1st Embodiment. It is an unbalance graph which shows a line voltage and a voltage unbalance rate. It is a load mobile power table which shows an example of mobile power of load. It is a generated movement electric power table which shows an example of the movement electric power of generation. It is a correction | amendment graph of the voltage unbalance rate after correct | amending by a correction coefficient. It is a comparison graph of unbalance rate change tendency and load change tendency. It is a power generation unbalance graph which shows the voltage unbalance rate of line voltage and photovoltaic power generation equipment. It is a power generation change trend graph which shows the power generation change trend of a photovoltaic power generation installation. It is a figure which shows an example of an unbalance information table. It is a figure which shows an example of a power transmission / reception electric power information table. It is a figure which shows an example of the process sequence of the system | strain unbalance reduction apparatus which concerns on 1st Embodiment. It is a figure which shows an example of the process sequence of the system | strain unbalance reduction apparatus which concerns on 1st Embodiment. It is an unbalance graph which shows an example of the condition which the system unbalance reduction apparatus concerning 1st Embodiment reduced the voltage unbalance ratio. It is the schematic which shows an example of the electric power system which concerns on 2nd Embodiment. It is a block diagram which shows an example of the system unbalance reduction apparatus which concerns on 2nd Embodiment. It is a figure which shows an example of the process sequence of the system | strain unbalance reduction apparatus which concerns on 2nd Embodiment. It is a load mobile power table which shows an example of mobile power of load. It is an unbalance graph which shows an example of the condition which the system unbalance reduction apparatus which concerns on 2nd Embodiment reduced the voltage unbalance ratio.

  At least the following matters will be made clear by the present specification and the description of the accompanying drawings. In the following description, the parts denoted by the same reference symbols represent the same elements, and the basic configuration and operation are assumed to be similar.

=== System imbalance reduction device 10 according to the first embodiment 10 ===
The grid imbalance reduction device 10 according to the first embodiment will be described below with reference to FIGS. 1 to 13.

  The grid imbalance reduction device 10 reduces the voltage unbalance of the power grid 100 to which the load 110 and the solar power generation facility 120 are connected as shown in FIG. Among the predetermined two phases (hereinafter referred to as "connected phases") of transformers 130 connected to power system 100, it is specified which connected phase of transformer 130 should be switched to which phase. It is an apparatus.

  More specifically, the grid imbalance reduction device 10 approximates the time change of the voltage unbalance rate of the power grid 100 (hereinafter referred to as “unbalance rate change tendency”), of the power consumption of the load 110. The time change (hereinafter referred to as "load change tendency") is specified. Among the loads 110 that exhibit the identified load change tendency, one or more loads 110 that meet the mobile power consumption are selected. By switching the connection phase corresponding to the selected load 110 to another phase, the worker can reduce the voltage unbalance of the power system 100 due to the load 110.

  After that, the grid imbalance reduction device 10 identifies a time change in generated power of the solar power generation facility 120 (hereinafter, referred to as “power generation change tendency”) that approximates the imbalance rate change tendency. Among the photovoltaic power generation facilities 120 showing the identified power generation change tendency, one or more photovoltaic power generation facilities 120 meeting the mobile power of the generated power are selected. By switching the connection phase corresponding to the selected solar power generation facility 120 to another phase, the worker can reduce the voltage unbalance of the electric power system 100 due to the solar power generation facility 120.

  As described above, the system unbalance reduction device 10 exhibits the same tendency as the unbalance rate change tendency of the power system 100, the load 110 corresponding to the load change tendency, and the solar power generation facility corresponding to the power generation change tendency By switching the connection phase of 120 to another phase, it is configured based on the new finding that the power imbalance ratio of the power system 100 can be reduced.

  As shown in FIG. 2, the system imbalance reduction device 10 includes an arithmetic processing unit 11, a storage unit 12, an input unit 13, an output unit 14, and a memory 15. The arithmetic processing unit 11, the storage unit 12, the input unit 13, the output unit 14, and the memory 15 are communicably connected.

  The arithmetic processing unit 11 includes, for example, a CPU or an MPU, and realizes various functions by reading a program stored in the memory 15. Further, the arithmetic processing unit 11 includes an unbalance calculation unit 11a, a time identification unit 11b, a mobile power calculation unit 11c, a correction calculation unit 11d, a load identification unit 11e, a load selection unit 11f, and a power generation identification unit 11g. And the power generation selection unit 11 h. The components of the arithmetic processing unit 11 will be described later in detail.

  The storage unit 12 is a device that stores programs and various information. The storage unit 12 is configured of, for example, a ROM, a RAM, a flash memory, or the like. The various tables stored in the storage unit 12 will be described in detail later.

  The input unit 13 is a network interface through which various information is input via a communication network (not shown). The output unit 14 is a network interface that outputs various information to a communication network (not shown). The memory 15 is a device for storing a program to be processed by the arithmetic processing unit 11. The memory 15 is configured by, for example, a hard disk drive, an SSD, an optical storage device, or the like.

  The grid imbalance reduction device 10 acquires information related to power such as voltage from a smart meter (not shown) provided in the load 110 and the solar power generation facility 120 via the input unit 13, for example.

== Arithmetic processing unit 11 ==
The arithmetic processing unit 11 of the system imbalance reduction device 10 will be described as follows with reference to FIGS. 2 to 9.

  As shown in FIG. 2, the arithmetic processing unit 11 refers to various tables in the storage unit 12 and calculates an imbalance calculation unit 11 a, a time identification unit 11 b, a moving power calculation unit 11 c, and a correction calculation unit 11 d. The functions of the load specification unit 11e, the load selection unit 11f, the power generation specification unit 11g, and the power generation selection unit 11h are exhibited. Each component will be described below.

<< Unbalance calculation unit 11a >>
The unbalance calculation unit 11 a has a function of calculating the voltage unbalance ratio of the power system 100 based on the line voltage information indicating the line voltage of each phase of the power system 100 acquired via the input unit 13. The voltage unbalance means that the equilibrium state of each phase is not maintained by causing a difference in the magnitude of the line voltage of each phase in the three-phase alternating current or causing a phase difference from 120 degrees. Say Further, the voltage unbalance rate indicates the degree of voltage unbalance as a percentage, and refers to the ratio of the negative phase voltage to the positive phase voltage. The voltage unbalance ratio of the three-phase line voltages (Vab, Vbc, Vca) is represented by a broken line in FIG. The unbalance calculation unit 11 a outputs, to the storage unit 12, voltage unbalance ratio information indicating the calculated voltage unbalance ratio. The arithmetic processing unit 11 may not have the unbalance calculation unit 11a, and in this case, for example, the voltage unbalance ratio information may be acquired from another device (not shown).

<< time identification unit 11b >>
The time specifying unit 11b has a function of specifying a time at which the voltage imbalance ratio on a predetermined day is the largest. For example, in FIG. 3, the time specifying unit 11 b specifies “H1” having the largest voltage imbalance ratio indicated by a broken line, and specifies a time corresponding to “H1” (hereinafter referred to as “maximum time”). Do. That is, the system unbalance reducing device 10 is configured to be able to improve the most severe situation of voltage unbalance. However, the present invention is not limited to specifying the maximum time. For example, a predetermined time may be specified between the sunrise and sunset of the solar power generation facility 120 generating power. The term "time" includes both meaning of "time" and "time zone", and the same applies hereinafter.

<< Moving Power Calculator 11c >>
The mobile power calculation unit 11c has a function of calculating the magnitude of power (hereinafter referred to as "mobile power") to switch one connection phase to another phase in the maximum time specified by the time specification unit 11b. . By calculating the mobile power, the load 110 and the solar power from the predetermined phase to the other phases in order to minimize the maximum value of the voltage imbalance ratio over the entire section over a predetermined plurality of time cross sections in power system 100. It is known how much the power generation facility 120 should be relocated.

After optimizing the phase proportions X _abi , X _bci , and X _cai of the load 110, the mobile power calculation unit 11 c calculates mobile power by calculating the difference from the inter-phase load capacity before movement. Specifically, the mobile power calculation unit 11 c calculates the phase-by-phase ratio of the load 110 and the phase-by-phase ratio of the photovoltaic power generation facility 120 based on the numbers 1 to 12 and is calculated by the numbers 1 to 12 Based on the result, mobile power is calculated using a function such as Excel's "solver". In addition, a solver carries out numerical processing based on fixed regularity, and it may replace with this solver and may compute movement power by artificial intelligence (neural network) or statistical processing.

In _Equations 1 to 12, S _abi , S _bci , and S _cai indicate single-phase capacities between the respective lines (ab phase, bc phase, ca phase). Further, “i” shown in the equations 1 to 12 indicates the number of the section. Also, P _abi , P _bci and P _cai indicate the effective power between the lines in the section i. Further, Equations 5 to 7 indicate single-phase capacities between the respective lines in the case of the load 110, and Equations 9 to 11 indicate single-phase capacities between the lines in the case of the photovoltaic power generation facility 120.

  The mobile powers calculated by the mobile power calculator 11 c are summarized as shown in FIG. 4. In FIG. 4, the "load transfer power" item indicates the destination of movement from one connection phase to another phase, and the "interval i" item indicates the amount of power to be switched. Specifically, for example, the item “load moving power” indicates that “ab → bc” switches the state connected in the ab phase to the bc phase, and the corresponding “section 3” item is “21 It is ". That is, it is shown that the power of "21" should be switched from the ab phase to the bc phase in order to reduce the voltage unbalance rate. The relationship between the “PV moving power” item and the “section i” item in FIG. 5 is the same as the relationship between the “load moving power” item and the “section i” item, so the description thereof will be omitted.

  Here, the arithmetic processing unit 11 may not have the mobile power calculation unit 11c. In this case, for example, the mobile power of power consumption as shown in FIG. 4 and FIG. You may get it.

<< correction calculation unit 11d >>
The correction calculation unit 11 d calculates a correction coefficient for removing the influence of the photovoltaic power generation facility 120 on the voltage imbalance ratio (hereinafter referred to as “first voltage imbalance ratio”) on a sunny day. It has a function. With this correction coefficient, for example, the average power of the non-power generation time zone on a sunny day (hereinafter referred to as "power generation day") is referred to on a non-bright day (hereinafter referred to as "non-power generation day"). It is a coefficient divided by the average power in the non-power generation time zone.

  As shown in Equation 13, the “correction value” in FIG. 6 can be obtained by applying the calculated correction coefficient to the voltage imbalance ratio on a non-generation day (hereinafter referred to as “second voltage imbalance ratio”). As shown on the power generation day, the influence on the voltage unbalance by the power generation of the solar power generation facility 120 can be removed. In other words, it is possible to calculate the voltage unbalance rate of the load 110 alone (hereinafter referred to as the “third voltage unbalance rate”) that does not include the power generation of the solar power generation facility 120 on the power generation day.

（補正係数：（発電日の非発電時間帯の平均電力）÷（非発電日の非発電時間帯の平均電力））
なお、非発電時間帯とは、季節によって異なる時間帯であり、例えば日没後から日出前の時間帯をいう。

(Correction factor: (average power of non-generation time zone of generation day) 平均 (average power of non-generation time zone of non-generation day))
The non-power generation time zone is a time zone that varies depending on the season, for example, a time zone from after sunset to before sunrise.

  Thus, since the connection phase can be appropriately switched only by the load 110 by removing the influence of the photovoltaic power generation facility 120 on the voltage unbalance on the power generation day, the photovoltaic power generation facility 120 is connected. Also in the power system 100, the voltage unbalance rate can be accurately reduced.

  In addition, in the above, although a correction coefficient was demonstrated as a coefficient which remove | divided the average electric power of the non-generation time slot | zone on a power generation day by the average power of the non-generation time slot | zone on a non power generation day, For example, coefficients predetermined in accordance with the season, time zone, etc. may be adopted, or coefficients calculated statistically by artificial intelligence (neural network etc.) may be adopted.

<< Load Identification Unit 11e >>
The load specifying unit 11 e specifies a load change tendency similar to the unbalance rate change tendency of the third voltage unbalance rate among the load change tendencies of the load 110 connected to the power system 100, and also specifies the specified load change It has a function of identifying the load 110 corresponding to the tendency.

  Specifically, as shown in FIG. 7, the unbalance rate change tendency (solid line) of the third voltage unbalance rate on the power generation day is compared with a plurality of load change tendencies (broken line) on a predetermined day. Note that FIG. 7 shows only one load change tendency (broken line) for the convenience of description. As a result of comparison, one or more load change tendencies that satisfy predetermined approximate conditions are identified. The conditions under which the unbalance rate change tendency and the load change tendency approximate are, for example, the third voltage unbalance at the second time after the first time with respect to the third voltage unbalance rate at the predetermined first time. A value obtained by averaging, in a predetermined period, the difference between the first ratio of the equilibrium rate and the second ratio of the power consumption of the load at the second time after the first time to the power consumption of the load at the first time It refers to the condition less than a predetermined value.

<< Load Selection Unit 11f >>
The load selection unit 11 f has a function of selecting a load 110 to be switched from the connection phase of the load 110 to another phase at the current time among the loads 110 specified by the load specification unit 11 e. The loads 110 to be selected are, for example, one or more loads 110 that consume power substantially equal to the mobile power of the target section at maximum time.

  Specifically, in the result shown in FIG. 4, for example, when the “load moving power” item is “ab → bc” and the corresponding “section 3” item is “21”, it is connected to the section 3 The load 110 is selected so that the total power consumption of one or more loads 110 among the loads 110 identified by the load identifying unit 11 e is “21”. This selection operation is performed on all sections of the power system 100 shown as an example in FIG.

  By the worker switching the connection phase of the selected load 110, as shown in FIG. 8, it is possible to calculate the voltage unbalance ratio in a state where the influence of the load 110 on the voltage unbalance on the power generation day is substantially eliminated.

<< Power Generation Identification Unit 11g >>
The power generation specifying unit 11 g is an imbalance calculation unit among power generation change trends determined according to the specifications of the photovoltaic power generation facility 120 connected to the power system 100 after the worker switches the connection phase of the selected load 110. It has a function of specifying a power generation change tendency close to the voltage unbalance rate of the power system 100 calculated in 11 a (hereinafter, referred to as “fourth voltage unbalance rate”). Further, the power generation specifying unit 11g specifies the solar power generation facility 120 corresponding to the specified power generation change tendency.

  Specifically, on a predetermined day as shown in FIG. 8, the unbalance rate change tendency of the fourth voltage unbalance rate on the power generation day (broken line) is compared with a plurality of power generation change tendencies as shown in FIG. Do. In addition, in FIG. 9, only one power generation change tendency (broken line) is shown for convenience of explanation. As a result of comparison, one or more power generation change trends that satisfy predetermined approximate conditions are identified.

<< Power Generation Selection Unit 11h >>
The power generation selection unit 11 h has a function of selecting a solar power generation facility 120 to be switched from the connection phase of the solar power generation facility to another phase at the present time among the solar power generation facility 120 specified by the power generation specification unit 11 g. The selected solar power generation facility 120 is, for example, a solar power generation facility 120 that generates power substantially equal to the mobile power of the target section at the maximum time.

  Specifically, in the result shown in FIG. 5, for example, when the “PV mobile power” item is “ab → bc” and the corresponding “section 3” item is “−20”, it is connected to the section 3 Of the solar power generation facilities 120 specified by the power generation specification unit 11g, the sum of the power generated by one or more of the solar power generation facilities 120 is “−20”. Select In addition, "-" display has shown that it is producing electric power. This selection operation is performed on all sections of the power system 100 illustrated as an example in FIG.

== storage unit 12 = =
The storage unit 12 will be described as follows with reference to FIGS. 10 and 11.

  The storage unit 12 has a function of storing various data for the arithmetic processing unit 11 to execute processing. As an example, the storage unit 12 stores an unbalanced information table 12a and a transmitted / received power information table 12b.

<< Unbalanced Information Table 12a >>
The unbalance information table 12a is a table in which voltage unbalance ratio information indicating the voltage unbalance ratio of the power system 100 is stored. As shown in FIG. 10, in the unbalanced information table 12a, at least an "inter-line voltage Vab" item indicating inter-line voltage information between the three phases a and b, and three phases b and c Stores the "line voltage Vbc" item indicating line voltage information between phases and the "line voltage Vca" item indicating line voltage information between c and a phases of three phases in association with each other It is done.

<< Transmission / reception power information table 12b >>
The power transmission / reception power information table 12 b is a table in which power consumption information indicating the power consumption of the load 110 connected to the transformer 130 is stored for each section divided by the switches in the power system 100. As shown in FIG. 11, the transmitted / received power information table 12b includes, for example, “section 1 to i” items indicating sections divided by switches, and the transformer 130 connected to the power system 100 in each section. The "Tmn" item indicating the power transmission / reception power information (power consumption information or generated power information) is stored in association with each other.

  The storage format of the unbalanced information table 12a and the transmitted / received power information table 12b is an example, and it may be a database format that can be referred to by the calculation processing unit 11. Further, the items stored in the unbalanced information table 12a and the transmitted / received power information table 12d are not limited, and the load 110 and the solar power generation facility 120 to be switched by the system unbalance reducing device 10 are not limited to the items. It only needs to include items necessary for selection.

== Procedure ==
The processing procedure of the system unbalance reduction apparatus 10 according to the first embodiment will be described as follows with reference to FIGS. 4, 5, 12 </ b> A, 12 </ b> B, and 13.

  First, the time specifying unit 11b specifies, for example, the voltage unbalance ratio indicating the highest value in the first voltage unbalance ratio of the power system 100 calculated by the unbalance calculation unit 11a, and indicates the voltage unbalance ratio. The maximum time is identified (S100).

  Next, the mobile power calculation unit 11c calculates mobile power of the optimal load 110 in the maximum time as shown in FIG. 4 (S101). The calculation method is as described above. As a result, with regard to the load 110, it can be understood which connection phase of which section, which power consumption should be switched to which phase.

  Next, the unbalance calculation unit 11a calculates a second voltage unbalance rate on a non-power generation day (S102). The second voltage imbalance ratio is stored in the imbalance information table 12a. However, when the system unbalance reducing device 10 does not have the unbalance calculating unit 11a, the second voltage unbalance rate of the non-power generation day is acquired from another device (not shown).

  Next, the correction calculation unit 11 d multiplies the second voltage unbalance rate on the non-power generation day by the correction coefficient to calculate the third voltage unbalance rate of only the load 110 on the power generation day (S 103).

  Next, the load specifying unit 11 e specifies the load 110 that exhibits a load change tendency that approximates the unbalance rate change tendency of the third voltage unbalance rate (S 104). In the step S104, under the condition that the unbalance rate change tendency and the load change tendency are similar, the connection phase of the load 110 showing the load change tendency is the same as the other phase by the moving power calculated by the moving power calculation unit 11c. To reduce the voltage unbalance due to the load 110.

  Next, the load selection unit 11 f selects one or more loads 110 equal to the mobile power shown in FIG. 4 among the specified one or more loads 110 (S 105). Thereby, the moving power necessary to improve the voltage unbalance rate of the power system 100 is satisfied by switching the connection phase of the load 110 showing another load change tendency close to the unbalance rate change tendency to another phase. be able to.

  Next, the worker switches the connection phase of the transformer 130 to which the selected load 110 is connected to another phase as shown in FIG. 4 (S106). In this state, the unbalance calculation unit 11a can calculate the fourth voltage unbalance rate which is brought close only to the influence of the solar power generation facility 120 (S107). In FIG. 12B, the solar power generation facility 120 is shown as “PV”.

  Next, the time specifying unit 11b specifies, for example, the voltage unbalance ratio indicating the highest value in the fourth voltage unbalance ratio of the power system 100, and specifies the maximum time indicating the voltage unbalance ratio (S108). .

  Next, the mobile power calculation unit 11c calculates mobile power of the optimal solar power generation facility 120 at the maximum time as shown in FIG. 5 (S109). The calculation method is as described above. As a result, it is possible to know which connection phase of which section should be switched to which phase and what generated power with respect to the photovoltaic power generation facility 120.

  Next, the power generation specifying unit 11g specifies a photovoltaic power generation facility 120 that exhibits a power generation change trend that approximates the imbalance ratio change trend of the fourth voltage imbalance ratio (S110). In the step S110, on the condition that the imbalance ratio change tendency and the power generation change tendency are similar, the connection phase of the solar power generation facility 120 showing the power generation change tendency is calculated by the mobile power amount calculated by the mobile power calculation unit 11c. It is a step to switch and reduce the voltage unbalance by the solar power generation facility 120.

  Next, the power generation selection unit 11 h selects one or more solar power generation facilities 120 equal to the mobile power shown in FIG. 5 among the specified one or more solar power generation facilities 120 (S 111). In addition, in FIG. 5, the solar power generation facility 120 is shown as "PV." Thereby, switching the connection phase of the photovoltaic power generation facility 120 showing the power generation change tendency close to the unbalance rate change trend to another phase, for moving power necessary for improving the voltage unbalance rate of the power system 100 Can be satisfied with

  Next, the worker switches the connection phase of the transformer 130 to which the selected solar power generation facility 120 is connected to another phase as shown in FIG. 5 (S112). In this state, as shown in FIG. 13, the voltage unbalance of the power system 100 is brought close to the state where the effects of the load 110 and the solar power generation facility 120 can be removed (S113).

=== System imbalance reduction device 20 according to the second embodiment ===
The grid imbalance reduction device 20 according to the second embodiment will be described in detail as follows, with reference to FIGS. 14 to 18.

  In the system unbalance reducing apparatus 10 according to the first embodiment described above, the load 110 and the solar power generation are performed to reduce the voltage unbalance in a state where the load 110 and the solar power generation facility 120 are connected to the power system 100. The calculation for switching the connection phase of the facility 120 is performed. On the other hand, in the system imbalance reduction device 20 according to the second embodiment, as shown in FIG. 14, the power system 200 without the solar power generation facility 120 connected (or ignoring the influence of the solar power generation facility 120). Calculation to switch the connection phase of the load 210 to reduce voltage unbalance.

  As shown in FIG. 15, the system imbalance reduction device 20 includes an arithmetic processing unit 21, a storage unit 22, an input unit 23, an output unit 24, and a memory 25. The arithmetic processing unit 21 includes an imbalance calculation unit 21a, a time identification unit 21b, a mobile power calculation unit 21c, a load identification unit 21d, and a load selection unit 21e. Each component has the same function as the system imbalance reduction device 10 according to the first embodiment, and thus the description thereof is omitted. In the following, the processing procedure of the system imbalance reduction device 20 will be described.

== Procedure ==
The processing procedure of the system imbalance reduction device 20 according to the second embodiment will be described as follows, with reference to FIG. 16, FIG. 17 and FIG.

  First, the time specifying unit 21b specifies, for example, the voltage unbalance ratio indicating the highest value in the voltage unbalance ratio of the power system 200 calculated by the unbalance calculating unit 21a, and the maximum time indicating the voltage unbalance ratio. Are identified (S200).

  Next, the mobile power calculation unit 21c calculates mobile power of the optimum load 210 at the maximum time as shown in FIG. 17 (S201). The calculation method is as shown in FIG. 4 described above. As a result, for the load 210, it can be understood which connection phase of which section, which power consumption should be switched to which phase.

  Next, the load specifying unit 21d specifies a load 210 that exhibits a load change tendency that approximates the unbalance rate change tendency of the voltage unbalance rate (S202). In S202, under the condition that the imbalance ratio change tendency and the load change tendency are similar, the connection phase of the load 210 showing the load change tendency is switched by the amount of the mobile power calculated by the mobile power calculator 21c, It is a step to reduce voltage unbalance by the load 210.

  Next, the load selection unit 21e selects one or more loads 210 equal to the mobile power shown in FIG. 17 among the identified one or more loads 210 (S203). Thereby, the moving power required to improve the voltage unbalance rate of the power system 200 is satisfied by switching the connection phase of the load 210 showing another load change tendency close to the unbalance rate change tendency to another phase. be able to.

  Next, the worker switches the connection phase of the transformer 220 to which the selected load 210 is connected to another phase as shown in FIG. 17 (S204). In this state, as shown in FIG. 18, the voltage unbalance due to the load 210 of the power system 200 can be reduced (S205).

=== Summary ===
As described above, in the power system 200 to which the load 210 is connected, the system imbalance reduction device 20 according to the present embodiment is the maximum at which the voltage unbalance rate of the power system 200 indicates a predetermined value on a predetermined day. Indicates the time change of the power consumed by the time specifying unit 21b specifying the time (first time) and the plurality of loads 210 connected to the connection phase (first connection phase) of the power system 200 on a predetermined day Load change tendency (first change tendency) similar to voltage unbalance rate change tendency (second change tendency) indicating time change of voltage unbalance rate of power system 200 among a plurality of load change tendencies (first change tendency) And a load identifying unit 21d that identifies the load 210 (first load) corresponding to the identified load change trend (first change trend), and the load identified in the maximum time (first time) 2 Of 0 (first load), a load 210 that consumes substantially the same power as the moving power of the power consumption to be switched from the connection phase (first connection phase) to the connection phase (second connection phase) different from the connection phase , And a load selection unit 21e to be selected. According to the present embodiment, it is possible to easily identify the load 210 which can reduce the voltage unbalance rate of the power system 200 by extracting the time change of the power consumption of the load 210 which approximates the time change of the voltage unbalance rate. Because it can do, voltage management work becomes easy.

  Further, the time specifying unit 21b of the grid imbalance reduction device 20 according to the present embodiment specifies, as the maximum time (first time), the time at which the voltage imbalance ratio of the power grid 200 shows the highest value on a predetermined day. . According to the present embodiment, the unbalance of the power system 200 can be most reduced by selecting the load 210 to which the connection phase should be switched at the maximum time at which the voltage unbalance rate shows the highest value.

  Moreover, the grid imbalance reduction device 20 according to the present embodiment can set the connection phase (first connection phase) between the connection phase (first connection phase) of the power grid 200 at the maximum time (first time). The mobile station further includes a mobile power calculation unit 21c that calculates mobile power of the power of the load 210 connected to the power system 200 to be switched between different connection phases (second connection phases). According to the present embodiment, the work efficiency can be improved by automating the work of calculating the mobile power.

  In the grid imbalance reduction device 10 according to the present embodiment, in the power grid 100 to which the load 110 and the solar power generation facility 120 are connected, the first voltage unbalance rate of the power grid 100 on a predetermined sunny day The time specifying unit 11b specifies the maximum time (second time) at which the predetermined value is indicated, and a correction coefficient for removing the influence of the photovoltaic power generation facility 120 on the first voltage imbalance ratio on a clear day The correction factor is applied to the second voltage unbalance rate of the power system 100 on a day that is not clear, and the third voltage unbalance rate of the power line 100 on a clear day that is affected by the load 110 is calculated. A plurality of load change tendencies (third change) indicating the time change of the power consumed by the correction calculation unit 11 d to be calculated and the plurality of loads 110 connected between the connection phase (third connection phase) of the power system 100 Identified a load change trend (third change trend) that approximates the unbalance rate change trend (the fourth change trend) indicating the time change of the third voltage unbalance rate among A connection phase (third connection) among the load specifying unit 11 e that specifies the load 110 (second load) corresponding to the tendency (third change tendency) and the load 110 (second load) specified at the second time And a load selection unit 11f that selects a load 110 that consumes substantially the same power as the mobile power (first mobile power) of the power to be switched between the connection phases (the fourth connection phase) different from the connection phase And. According to the present embodiment, it is possible to extract the time change of the power consumption of the load 110 which approximates the time change of the voltage unbalance rate in the situation where the photovoltaic power generation facility 120 is generating power. The voltage management task is facilitated because the load 110 that can reduce the equilibrium rate can be easily identified.

  In addition, the system unbalance reduction device 10 according to the present embodiment allows the selected load 110 (second load) to be transmitted from the connection phase (third connection phase) in the power system 100 to another connection phase (fourth connection phase). ), The time identifying unit 11b identifies the maximum time (third time) at which the fourth voltage imbalance rate of the power system 100 on a clear day indicates a predetermined value, and Among the plurality of power generation change trends (fifth change trend) showing the time change of the generated power determined according to the specifications of each of the plurality of photovoltaic power generation facilities 120 connected between the connection phases (fifth connection phase), (4) Identify the power generation change trend (fifth change trend) that approximates the unbalance rate change trend (sixth change trend) showing the time change of the 4-voltage unbalance rate, and identify the power generation change trend identified (fifth change trend) Solar power generation equipment 120 corresponding to Connection phase (sixth connection phase different from between connection phases (fifth connection phase) among connection phases (fifth connection phase) of the photovoltaic power generation facility 120 specified in the maximum time (third time) of the power generation specifying unit 11g to be determined And a power generation selection unit 11 h that selects a solar power generation facility 120 that generates power substantially equal to the mobile power of the power to be switched between (the second mobile power). According to the present embodiment, by extracting the time change of the generated power of the solar power generation facility 120 which approximates the time change of the voltage unbalance rate, the solar power generation capable of reducing the voltage unbalance rate of the power system 100 Since the facility 120 can be easily identified, voltage management work is facilitated.

  The above embodiments are for the purpose of facilitating the understanding of the present invention, and are not for the purpose of limiting and interpreting the present invention. The present invention can be modified and improved without departing from the gist thereof, and the present invention also includes the equivalents thereof.

10, 20 System imbalance reduction device 11a, 21a Unbalance calculation unit 11b, 21b Time identification unit 11c, 21c Moving power calculation unit 11d Correction calculation unit 11e, 21d Load identification unit 11f, 21e Load selection unit 11g Power generation identification unit 11h Power generation Selection unit 100, 200 Power grid 110, 210 Load 120 Photovoltaic power plant 130, 220 Transformer

Claims (9)

In the power system to which the load is connected,
A time specifying unit for specifying a first time in which a voltage unbalance rate of the power system shows a predetermined value on a predetermined day;
Among the plurality of first change trends indicating the time change of the power consumed by the plurality of loads connected to the first connection phase of the power system on the predetermined day, the time of the voltage unbalance ratio of the power system A load identification unit that identifies the first change trend that approximates a second change trend that indicates a change, and identifies a first load that corresponds to the identified first change trend;
A load which consumes substantially the same power as mobile power indicating power consumption to be switched to the second connection phase different from the first connection phase from the first connection phase in the first time, The load selection unit to select
A system imbalance reduction device comprising: The grid imbalance reduction device according to claim 1, wherein the time identification unit identifies a time in which the voltage unbalance rate of the power system shows the highest value on the predetermined day as a first time. The moving power of the power of the load connected to the power system to be switched between the first connection phase of the power system and the second connection phase different from the first connection phase at the first time is calculated. The system unbalance reduction device according to claim 1 or 2, further comprising: a mobile power calculation unit. In the power system to which the load is connected,
Identifying a first time at which a voltage unbalance rate of the power system shows a predetermined value on a predetermined day;
A second change tendency of the voltage unbalance ratio of the power system among the first change tendency showing a time change of the power consumed by the load connected between the first connection phases of the power system on the predetermined day Specifying the first change tendency that approximates the change tendency, and specifying a first load corresponding to the specified first change tendency;
Among the first loads, a load which consumes substantially the same power as the mobile power of the power to be switched between the first connection phase and the second connection phase different from the first connection phase is selected in the first time. ,
System unbalance reduction method characterized in that. In the power system to which the load and the solar power generation facility are connected,
A time specifying unit for specifying a second time in which the first voltage unbalance rate of the power system shows a predetermined value on a predetermined sunny day;
While calculating the correction coefficient for removing the influence of the solar power generation facility on the first voltage unbalance rate on a sunny day, the second voltage unbalance rate of the power system on a day that is not clear is calculated. A correction calculation unit that applies a correction coefficient to calculate a third voltage unbalance rate of the power system on a sunny day, the load being affected;
The fourth change tendency showing the time change of the third voltage unbalance rate among the plurality of third change tendencies showing the time change of the power consumed respectively by the plurality of loads connected between the third connection phases of the power system A load identification unit that identifies the third change tendency that approximates the above, and identifies a second load that corresponds to the identified third change tendency;
Among the second loads, a load which consumes substantially the same power as the first mobile power of the power to be switched between the third connection phase and the fourth connection phase different from the third connection phase in the second time, The load selection unit to select
A system imbalance reduction device comprising: In the situation where the selected second load is switched between the third connection phase and the fourth connection phase in the power system,
The time specifying unit specifies a third time in which the fourth voltage imbalance ratio of the power system on a clear day shows a predetermined value,
The fourth voltage imbalance ratio among the plurality of fifth change trends indicating the time change of the generated power determined according to the specifications of the plurality of solar power generation facilities connected between the fifth connection phase of the power system A power generation specification unit that specifies the fifth change tendency that approximates the sixth change tendency that indicates the time change of the power generation unit, and specifies the solar power generation facility that corresponds to the specified fifth change tendency;
Of the solar power generation facilities specified in the third time, the electric power approximately equal to the second mobile power of the electric power to be switched between the fifth connection phase to the sixth connection phase different from the fifth connection phase is generated A power generation selection unit for selecting the solar power generation facility to be
The system imbalance reduction device according to claim 5, further comprising: The grid failure according to claim 6, wherein the time identification unit identifies, as the second time, a time at which the voltage unbalance ratio of the power grid exhibits the highest value on the predetermined sunny day. Balance reduction device. Calculating the first mobile power of the power of the load connected to the power system to be switched between the third connection phase of the power system to the fourth connection phase at the second time;
Mobile power calculation for calculating the second mobile power of the power of the solar power generation facility connected to the power system to be switched between the fifth connection phase of the power system to the sixth connection phase at the third time The system imbalance reduction apparatus according to any one of claims 5 to 7, further comprising: In the power system to which the load and the solar power generation facility are connected,
Identifying a second time during which the first voltage imbalance ratio of the power system shows a predetermined value on a predetermined sunny day;
While calculating the correction coefficient for removing the influence of the solar power generation facility on the first voltage imbalance rate on a sunny day, the second voltage imbalance rate of the electric power system on a day that is not sunny is calculated. Apply a correction factor to calculate the third voltage imbalance rate of the power system on a sunny day, which only the load is affected,
The fourth change tendency showing the time change of the third voltage unbalance rate among the plurality of third change tendencies showing the time change of the power consumed respectively by the plurality of loads connected between the third connection phases of the power system And identifying a second load corresponding to the identified third change tendency,
In the second time, the second load consumes substantially the same power as the first mobile power of the power to be switched between the third connection phase and the fourth connection phase different from the third connection phase among the second loads. Select the load,
System unbalance reduction method characterized in that.

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