Information processing device, information processing method, and program

Abstract

To provide an information processing device capable of accurately determining a construction method capable of making an improvement in a voltage unbalance rate of a three-phase power transmission / distribution line.SOLUTION: An information processing device comprises: a calculation section for calculating an unbalance rate of a voltage in each of n pieces of nodes based on a plurality of combinations obtained as any of a first state where a state of a connection phase connecting a pole transformer in each of m pieces of nodes in a power system to a three-phase power transmission / distribution line is not changed, a second state where the state of the connection phase is changed in a first pattern or a third state where the state of the connection phase is changed in a second pattern which is different from the first pattern, power exchanged with the power system in each of the n pieces of nodes, and system configuration information indicating a configuration of the power system; and a determination section for determining the state of the connection phase connecting the pole transformer in each of the m pieces of nodes based on a calculation result of the unbalance rate of the voltage.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an information processing device, an information processing method, and a program. [Background technology]

[0002] In the transmission or distribution lines of a power system (hereinafter referred to as "power transmission and distribution lines"), the voltage variation for each phase is calculated by the voltage unbalance rate (hereinafter referred to as "unbalance rate"), and it is desirable for the unbalance rate to be small. Therefore, there is a technology to improve the unbalance rate by performing a twisting operation on the power system so that the load of the power system is connected to each phase in a balanced manner.

[0003] For example, Patent Document 1 describes a cable rack position determining device that determines the cable rack position in a three-phase power transmission and distribution line. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2015-126679 A Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, devices such as photovoltaic power generation devices and electric vehicle chargers are sometimes installed in power systems. Irregular load fluctuations or power generation fluctuations caused by these devices increase the voltage imbalance. However, the technology described in Patent Document 1 does not take into account actual load fluctuations or power generation fluctuations, and therefore it is not always possible to determine the position of the cable rack that can improve the voltage unbalance rate and the cable rack pattern (how to switch phases) at that position. In addition, when localized unbalances are scattered in the power system, changing the connection phase of the pole transformer at the point where the unbalance occurs may be able to effectively eliminate the unbalance with less construction work than taking measures using cable racks.

[0006] The present invention has been made in consideration of the above-mentioned conventional problems, and has an object to provide an information processing device, an information processing method, and a program that can accurately determine a construction method that can efficiently improve the voltage unbalance rate of a three-phase transmission / distribution line. [Means for solving the problem]

[0007] The main present invention for solving the above-mentioned problems includes an information processing device that includes a calculation unit that calculates a voltage unbalance rate of each of the n nodes based on a plurality of combinations obtained as a state of a connection phase in which a pole transformer at each of m nodes in a power system is connected to a three-phase transmission / distribution line, the state being either a first state in which the state is not changed, a second state in which the state is changed in a first pattern, or a third state in which the state is changed in a second pattern different from the first pattern, power exchanged with the power system at each of the n nodes, and system configuration information indicating the configuration of the power system, and a determination unit that determines a state of the three-phase transmission / distribution line at each of the m nodes based on a calculation result of the voltage unbalance rate. Effect of the Invention

[0008] According to the present invention, it is possible to determine with high accuracy a construction method capable of efficiently improving the voltage unbalance rate of a three-phase transmission / distribution line. [Brief description of the drawings]

[0009] [Figure 1] 1 is a diagram illustrating a hardware configuration of an information processing device 10 according to a first embodiment of the present invention. [Diagram 2] FIG. 1 is a diagram illustrating an example of a power system 20 for which an information processing device 10 according to a first embodiment determines a construction method. [Diagram 3] 1 is a configuration diagram showing an example of functions and databases included in an information processing device 10 according to a first embodiment. [Figure 4] 3 is a schematic diagram showing a data configuration and an example of data of system configuration information according to the first embodiment. FIG. [Diagram 5]4 is a schematic diagram showing a data configuration and an example of data of accessory device information according to the first embodiment. FIG. [Figure 6] 3 is a schematic diagram showing a data configuration and an example of data of the smart meter master according to the first embodiment. FIG. [Figure 7] 4 is a schematic diagram showing a data configuration and an example of data in a smart meter measurement value table according to the first embodiment. FIG. [Figure 8] 3 is a schematic diagram showing an example of transformer power data output by a transformer power calculation unit 13 according to the first embodiment. FIG. [Figure 9] FIG. 2 is a diagram illustrating an example of detailed functional blocks of an imbalance eliminating unit 15 according to the first embodiment. [Figure 10] FIG. 4 is a diagram for explaining a decision process according to the first embodiment. [Figure 11] FIG. 4 is a diagram for explaining a decision process according to the first embodiment. [Figure 12] FIG. 4 is a diagram for explaining a decision process according to the first embodiment. [Figure 13] 4 is a schematic diagram showing an example of an unbalance rate calculation result table generated by the imbalance eliminating unit 15 according to the first embodiment. FIG. [Figure 14] 4 is a schematic diagram showing an example of an objective function calculation result table generated by the imbalance eliminating unit 15 according to the first embodiment. FIG. [Figure 15] 13 is a flowchart illustrating an example of an imbalance resolution process according to the first embodiment. [Figure 16] FIG. 13 is a diagram showing the distribution of annual maximum unbalance rates in a power system 20 before construction work. [Figure 17] FIG. 13 is a diagram showing the distribution of annual maximum unbalance rates in the power system 20 after construction is performed using a construction method determined by a determination process. [Figure 18] FIG. 13 is a diagram showing the distribution of the annual maximum unbalance rate in the power system 20 after construction in accordance with the state of transformer connection switching determined by the determination process. [Figure 19] FIG. 13 is a diagram showing the distribution of the annual maximum unbalance rate in the power system 20 after construction is performed to the rack state determined by the determination process. [Figure 20]13 is a flowchart showing an example of an imbalance resolution process according to the second embodiment of the present invention. [Figure 21] FIG. 11 is a configuration diagram showing an example of functions and databases included in an information processing device 10A according to a third embodiment of the present invention. [Figure 22] 13 is a schematic diagram showing a data configuration and an example of data in a sensor measurement value table according to the third embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] At least the following points will become apparent from the description of this specification and the accompanying drawings.

[0011] =====First embodiment===== <<<Configuration of information processing device 10>>> First, the first embodiment will be described. Fig. 1 is a diagram showing a hardware configuration of an information processing device 10 according to an embodiment of the present invention. The information processing device 10 is, for example, a device that determines a construction method for eliminating an imbalance in a power system 20 (described later) shown in Fig. 2. Construction methods include a method of twisting the phase of a transmission / distribution line by twisting, and a method of changing the connection phase at which a pole transformer is connected to a transmission / distribution line by construction (hereinafter referred to as "transformer reconnection"). Twisting refers to switching the phase in a power system by disconnecting a transmission / distribution line midway and reconnecting it by construction.

[0012] The information processing device 10 is a computer including a CPU (Central Processing Unit) 101, a memory 102, an input unit 103, an output unit 104, a storage unit 105, a recording medium driving unit 106, and a network connection unit 107. The CPU 101, the memory 102, the input unit 103, the output unit 104, the storage unit 105, the recording medium driving unit 106, and the network connection unit 107 are communicatively connected to each other via a bus.

[0013] The CPU 101 executes programs stored in the memory 102 or the storage unit 105 to realize various functions of the information processing device 10. The memory 102 is, for example, a RAM (Random-Access Memory) and is used as a temporary storage area for programs and data for determining a construction method.

[0014] The input unit 103 is a device that accepts commands and data input by a user, and includes an input interface such as a keyboard, a touch sensor that detects a touch position on a touch panel display, etc. The output unit 104 is, for example, a display device such as a display, or an output device such as a printer.

[0015] The storage unit 105 is a non-volatile storage device that is configured by, for example, a hard disk, a USB (Universal Serial Bus) memory, a memory card, or the like, and stores programs to be executed or processed by the CPU 101 or various data.

[0016] The recording medium drive unit 106 is connected to a recording medium 6 such as an optical disk or a compact disk, and reads data from the recording medium 6 or writes data thereto.

[0017] A network connection unit 107 exchanges various programs and data with other computers via a network (not shown).

[0018] <<<An example of power system 20>>> 2 is a diagram showing an example of a power system 20 for which the information processing device 10 determines a construction method. The power system 20 is, for example, a 6.6 kV power transmission and distribution line system, and includes a distribution substation 21 consisting of a transformer 211 and a circuit breaker 212, a power transmission and distribution line 22, a sensor-integrated switch 23, multiple pole transformers TR (TR1 to TR5), and multiple watt-hour meters SM (SM1 to SM5). The power transmission and distribution line 22 is provided with nodes N (N0 to N5) to which the sensor-integrated switch 23 or the multiple pole transformers TR are connected, respectively. The power system 20 may also be composed of a private line.

[0019] The transformer 211 transforms the voltage supplied from a power transmission line (not shown) and outputs a voltage of 6.6 kV to the power transmission / distribution line 22. The circuit breaker 212 is a device, such as a distribution circuit breaker or a feeder circuit breaker, that cuts off a current to protect the power system 20 when an accident such as a short circuit or a ground fault occurs in the power system 20.

[0020] The power transmission / distribution line 22 is a three-phase power transmission / distribution line for supplying power from the transformer 211 to each consumer, and extends downstream from the transformer 211 on the upstream side. The power transmission / distribution line 22 is a power line for supplying three-phase AC power of U-phase, V-phase, and W-phase from the transformer 211. The power transmission / distribution line 22 has a power transmission / distribution line 221 for supplying U-phase power, a power transmission / distribution line 222 for supplying V-phase power, and a power transmission / distribution line 223 for supplying W-phase power. Hereinafter, the multiple phases may be collectively referred to as UV phases (U phase and V phase), VW phases (V phase and W phase), WU phase (W phase and U phase), or UVW phases (U phase, V phase, and W phase).

[0021] A node N is an arbitrary management unit provided on the power transmission / distribution line 22. In this embodiment, the node N is an aggregated unit managed by pole transformer TR. The node N is a candidate location for construction work (stretching or transformer reconnection). For ease of explanation, the node N with node number "i (i is an integer)" will be referred to as node Ni below. The node number is an identification number that identifies each node N. For example, the node N with node number "0" will be referred to as node NO. Note that for matters common to each node N, the node number will be omitted and it will be simply referred to as "node N" or "each node N."

[0022] The sensor-embedded switch 23 is a switch having a sensor capable of periodically measuring at least the measured values ​​of the voltage and current at a point of installation. The point of installation of the sensor-embedded switch 23 is the node N0.

[0023] The pole transformer TR is a transformer connected to the power transmission / distribution line 22. The pole transformer TR is a transformer that transforms, for example, a voltage on the primary side at a predetermined transformation ratio and outputs the transformed voltage from the secondary side. The primary sides of the pole transformers TR1 to TR4 are each connected to any two-phase (two lines) power transmission / distribution line 22 of the power transmission / distribution lines 221 to 223, and the primary side of the transformer TR5 is connected to the power transmission / distribution lines 221 to 223. The secondary sides of the pole transformers TR1 to TR5 are each connected to a consumer. The consumer is a person who uses the power supplied from the power transmission / distribution line 22, and each has a load that consumes the power. The power output by the transformer 211 to the power transmission / distribution line 22 is distributed to the consumer via the pole transformer TR. For ease of explanation, hereinafter, a pole transformer TR with an ancillary device ID "TRi" will be referred to as a pole transformer TRi. The ancillary device ID is identification information that identifies each ancillary device (sensor-integrated switch 23 or pole transformer TR). For example, a pole transformer TR with an ancillary device ID "TR1" will be referred to as a pole transformer TR1. Note that numbers will be omitted for matters common to each pole transformer TR, and they will simply be referred to as "pole transformer TR" or "each pole transformer TR."

[0024] The watt-hour meter SM is installed at a consumer at a predetermined node N of the power transmission / distribution line 22. A so-called smart meter can be used as the watt-hour meter SM. The watt-hour meter SM measures the measured value of the amount of power used (load or power generation) of the consumer at a predetermined period. Hereinafter, for convenience of explanation, the watt-hour meter SM with the smart meter ID "SMi" is referred to as the watt-hour meter SMi. The smart meter ID is identification information for identifying each watt-hour meter SM. For example, the watt-hour meter SM with the smart meter ID "SM1" is referred to as the watt-hour meter SM1. Note that, for matters common to each watt-hour meter SM, the numbers are omitted and it is simply referred to as the "watt-hour meter SM" or "each watt-hour meter SM." Note that, in this figure, a configuration in which one watt-hour meter SM is connected to each pole transformer TR is illustrated, but multiple watt-hour meters SM (i.e., consumers) may be connected to one pole transformer TR.

[0025] <<<Details of information processing device 10>>> FIG. 3 is a configuration diagram showing an example of functions and databases included in the information processing device 10. As shown in FIG.

[0026] The information processing device 10 is communicatively connected to each of the watt-hour meters SM in the power system 20 via a communication line 30. The information processing device 10 has a system configuration database 11, a smart meter information database 12, a transformer power calculation unit 13, a data generation unit 14, an imbalance resolution unit 15, and a result output unit 16. The system configuration database 11 and the smart meter information database 12 are stored in advance in a storage unit 105 of the information processing device 10. In addition, the CPU 101 reads a predetermined program stored in the storage unit 105 into the memory 102 and executes or processes the program, thereby realizing the functions of the transformer power calculation unit 13, the data generation unit 14, the imbalance resolution unit 15, and the result output unit 16 in the information processing device 10.

[0027] The system configuration database 11 is a database that stores system configuration information indicating the configuration of the power system 20, and auxiliary equipment information indicating information on the auxiliary equipment (sensor-integrated switch 23 and pole transformer TR) that the power system 20 has.

[0028] 4 is a schematic diagram showing a data structure and an example of data of the system configuration information. As shown in the figure, the system configuration information has items of a node number, a utility pole number, a latitude, a longitude, a connected utility pole number, a distribution line R (U phase), a distribution line X (U phase), a distribution line R (V phase), a distribution line X (V phase), a distribution line R (W phase), a distribution line X (W phase), and an auxiliary device ID.

[0029] The node number is identification information for identifying each node N. The utility pole number is the identification number of the utility pole on which the node N is located. The latitude is the latitude of the position where the utility pole is installed. The longitude is the longitude of the position where the utility pole is installed. The connection pole number is the utility pole number of the upstream utility pole to which the utility pole is connected via the transmission / distribution line 22. The distribution line R (U phase) is the resistance of the line in the U phase (unit: Ω (ohms)). The distribution line X (U phase) is the reactance in the U phase (unit: Ω). The distribution line R (V phase) is the resistance of the line in the V phase (unit: Ω). The distribution line X (V phase) is the reactance in the V phase (unit: Ω). The distribution line R (W phase) is the resistance of the line in the W phase (unit: Ω). The distribution line X (W phase) is the reactance (unit: Ω) in the W phase. The auxiliary device ID is identification information of the auxiliary device arranged at the node N.

[0030] FIG. 5 is a schematic diagram showing a data configuration and an example of data of the additional device information. As shown in the figure, the additional device information has items of an additional device ID, an additional device type, and a connection phase. The additional device ID is identification information for identifying each additional device (the sensor-embedded switch 23 or the pole transformer TR). The additional device type is the type of the additional device. For example, the additional device ID "SE1" is the sensor-embedded switch 23, and the additional device IDs "TR1" to "TR5" are the pole transformers TR. The connection phase is the phase of the power transmission / distribution line 22 to which the additional device is connected. In the example shown in the figure, for example, the sensor-embedded switch 23 is connected to the UVW phase (i.e., all phases of the U phase, the V phase, and the W phase). Also, the pole transformer TR1 is connected to the UV phase (i.e., two phases of the U phase and the V phase).

[0031] Returning to Fig. 3, we will continue to explain the functional configuration of the information processing device 10. The smart meter information database 12 is a database that stores a smart meter master indicating information related to each of the watthour meters SM, and a smart meter measurement value table indicating periodic measurement values ​​measured by each of the watthour meters SM.

[0032] Fig. 6 is a schematic diagram showing the data configuration and an example of data in the smart meter master. As shown in the figure, the smart meter master has the following items: smart meter ID, connected pole transformer ID, model, and rated voltage. The smart meter ID is identification information for identifying each watt-hour meter SM. The connected pole transformer ID is an accessory device ID of the pole transformer TR to which the watt-hour meter SM is connected. The model is the model of the watt-hour meter SM. The rated voltage is the rated voltage of the watt-hour meter SM.

[0033] FIG. 7 is a schematic diagram showing a data configuration and an example of data in a smart meter measurement value table. As shown in the figure, the smart meter measurement value table has items of measurement date and time, smart meter ID, and meter measurement value. The measurement date and time is the date and time (year, month, day, hour, minute) when the meter measurement value was measured. The meter measurement value is a measurement value (in units of kWh (kilowatt hours)) of the amount of power used by a consumer measured by a power meter SM. In the example shown in the figure, the measurement value of each power meter SM every 30 minutes is stored in the smart meter measurement value table. That is, in this example, each power meter SM measures the amount of power used by a consumer at a fixed cycle of every 30 minutes.

[0034] The data stored in the smart meter measurement value table may be pre-stored in the memory unit 105, or may be updated at any time by the CPU 101 acquiring meter measurement values ​​from each electricity meter SM via the communication line 30 and writing the acquired meter measurement values ​​to the smart meter measurement value table.

[0035] Returning to Fig. 3, the functional configuration of the information processing device 10 will be further described. The transformer power calculation unit 13 calculates the distribution of power states (load or power generation) (hereinafter referred to as "load distribution") for each pole transformer TR based on the information stored in the system configuration database 11 and the smart meter information database 12. In this embodiment, the transformer power calculation unit 13 calculates the average power consumption of each pole transformer TR as the load distribution.

[0036] Hereinafter, a method for calculating the average power consumption will be specifically described using an example of data shown in FIG. 7, taking as an example a case where the average power consumption of the pole transformer TR1 for 30 minutes from the measurement date and time "2019 / 12 / 10 9:00" to the measurement date and time "2019 / 12 / 10 9:30". First, the transformer power calculation unit 13 refers to the smart meter master in FIG. 6 to identify the watt-hour meter SM1 connected to the pole transformer TR1. Then, the transformer power calculation unit 13 subtracts the meter measurement value "1500" of the watt-hour meter SM1 at the measurement date and time "2019 / 12 / 10 9:00" from the meter measurement value "1550" of the watt-hour meter SM1 at the measurement date and time "2019 / 12 / 10 9:30" to calculate the 30-minute power measurement value "50 kWh (= 1550 - 1500)". Then, the transformer power calculation unit 13 divides the power measurement value "50 kWh" by "0.5 hours (30 minutes)" to calculate the average power consumption of the pole transformer TR1 for 30 minutes "100 kW (kilowatts) (= 50 kWh ÷ 0.5 h)". Similarly, the transformer power calculation unit 13 calculates the average power consumption of the pole transformer TR2 "150 kW", the average power consumption of the pole transformer TR3 "50 kW", the average power consumption of the pole transformer TR4 "80 kW", and the average power consumption of the pole transformer TR5 "200 kW". The transformer power calculation unit 13 then outputs transformer power data indicating the calculated average power consumption of each pole transformer TR to the data generation unit 14.

[0037] 8 is a schematic diagram showing an example of transformer power data output by the transformer power calculation unit 13. The transformer power data has the following items: measurement date and time, accessory device ID, and transformer power. The measurement date and time is the date and time (year, month, day, hour, minute) when the meter measurement value used to calculate the transformer power was measured. The transformer power is the average power consumption (unit: kW) of the pole transformer TR for the 30 minutes immediately preceding the measurement date and time.

[0038] In the illustrated example, the load distribution is shown in a single time section at "2019 / 12 / 10 9:30", but multiple time sections may be used. In the present embodiment, the load distribution is described using only active power, but reactive power may also be set.

[0039] Returning to FIG. 3, the functional configuration of the information processing device 10 will be described. The data generating unit 14 generates input data based on the system configuration database 11 and the transformer power data. The input data indicates the load of each phase at each node N. First, the data generating unit 14 identifies the utility pole on which each pole transformer TR is installed, the connection relationship between utility poles, and the impedance of each distribution line by referring to the system configuration information and the auxiliary equipment information stored in the system configuration database 11. For example, the data generating unit 14 identifies the phase to which the pole transformer TR arranged at each node N is connected based on the system configuration information and the auxiliary equipment information, and sets the load for the identified phase as the transformer power of the pole transformer TR. In the data examples shown in FIG. 4 and FIG. 5, for example, the data generating unit 14 identifies that the pole transformer TR1 arranged at the node N1 is connected to the UV-phase distribution line. Then, the data generating unit 14 refers to the transformer power data, and sets the load of the UV phase at node N1 to the transformer power of pole transformer TR1 "100", the load of the VW phase to "0", and the load of the WU phase to "0". The data generating unit 14 then outputs input data indicating the load of each phase at each of all nodes N to the unbalance eliminating unit 15.

[0040] The unbalance resolution unit 15 executes a determination process for determining a construction method (the state of the racking and the state of the transformer reconnection) that efficiently reduces the unbalance rate in the power system 20 based on the input data. The state of the racking is the racking position and the racking pattern at that position. The racking position is the position at which the transmission / distribution line 22 is racked (in this embodiment, any one of the multiple nodes N). The racking pattern is the way in which each phase is switched (twisted). The state of the transformer reconnection is the transformer reconnection position and the transformer reconnection pattern at that position. The transformer reconnection position is the position at which the connection phase of the pole transformer TR is changed (in this embodiment, any one of the multiple nodes N). The transformer reconnection pattern is the way in which the connection phase is changed (hereinafter referred to as "reconnection").

[0041] 9 is a diagram showing an example of detailed functional blocks of the imbalance resolution unit 15. The imbalance resolution unit 15 includes a calculation unit 151 and a determination unit 152.

[0042] The calculation unit 151 executes a calculation process to calculate the voltage unbalance rate of each of n nodes N based on a plurality of combinations obtained by taking the state of the connection phase where the pole transformer TR at each of m (m is a positive integer) nodes N in the power system 20 is connected to the transmission / distribution line 22 as any one of a first state to a third state, a plurality of combinations obtained by taking the state of the transmission / distribution line 22 at each of the m nodes N in the power system 20 as any one of a fourth state to a sixth state, the power exchanged with the power system at each of the n (n is a positive integer) nodes N, and system configuration information.

[0043] Here, the first state of the connection phase is a state in which the connection phase is not changed, the second state of the connection phase is a state in which the connection phase is changed in a first pattern, and the third state of the connection phase is a state in which the connection phase is changed in a second pattern different from the first pattern. The fourth state of the transmission / distribution line 22 is a state in which the transmission / distribution line 22 is not crossed, the fifth state of the transmission / distribution line 22 is a state in which the transmission / distribution line 22 is crossed in a third pattern, and the sixth state of the transmission / distribution line 22 is a state in which the transmission / distribution line 22 is crossed in a fourth pattern different from the third pattern. Details of the first to fourth patterns will be described later. The m nodes N in this embodiment are all the nodes N provided in the transmission / distribution line 22, but are not limited thereto, and may be a plurality of nodes N selected in advance from the nodes N provided in the transmission / distribution line 22. Moreover, the n nodes N in this embodiment are nodes N to which the watt-hour meters SM (pole transformers TR) are connected (i.e., all nodes N other than the node NO where the sensor-integrated switch 23 is arranged). Furthermore, in this embodiment, the calculation unit 151 calculates the power exchanged with the power system 20 at each of the n nodes by using the measurement values ​​of the watt-hour meters SM connected to each of the n nodes.

[0044] The determination unit 152 executes a determination process for determining the state of the power transmission / distribution line 22 at each of the m nodes and the state of the connection phase to which the pole transformer TR is connected, based on the calculation result of the voltage unbalance rate. That is, the determination unit 152 determines the construction method in the power system 20 (the state of the suspension and the state of the transformer reconnection).

[0045] The determination process executed by the imbalance resolving unit 15 will be described in detail with reference to Fig. 10 to Fig. 14. Fig. 10 to Fig. 12 are diagrams for explaining the determination process.

[0046] First, the unbalance resolving unit 15 assigns the load of each phase at each node N to the variable "node[i].load setting[j]" based on the input data, as shown in table T100 in FIG. 10. Here, the index "i" of the array "node" indicates the node number. Also, the index "j" of the array "load setting" takes three values ​​of 0, 1, and 2, with "0" indicating the UV phase, "1" indicating the VW phase, and "2" indicating the WU phase. For example, node[i].load setting "0" indicates the load of the UV phase at node N with node number "i", node[i].load setting "1" indicates the load of the VW phase at node N with node number "i", and node[i].load setting "2" indicates the load of the WU phase at node N with node number "i". Also, the load in this embodiment is the transformer power of the pole transformer TR arranged at node N. The unbalance resolution unit 15 assigns the transformer power of the pole transformer TR to the "load setting" corresponding to the phase to which the pole transformer TR is connected. For example, since the pole transformer TR1 located at node N1 is connected to the UV phase, the unbalance resolution unit 15 sets the node[1].load setting[0] to the transformer power of the pole transformer TR1 "100" (node[1].load setting[0]=100).

[0047] Next, the imbalance resolution unit 15 generates a construction pattern p for the power system 20. The construction pattern p is a combination of racking patterns at each of the m nodes N, and a combination of transformer connection switching patterns at each of the m nodes N. For example, as shown in table T200 in Fig. 10, the imbalance resolution unit 15 defines the generated combination of racking patterns using an array of discrete values ​​by the variable "node[n].racking pattern", and defines the combination of transformer connection switching patterns using an array of discrete values ​​by the variable "node[n].transformer connection switching pattern".

[0048] The variable "stretching pattern" takes three values, 0, 1, and 2, and "0" indicates that the transmission / distribution line 22 is not twisted (not twisted). "1" indicates a third pattern in which the U phase is swapped with the V phase, the V phase with the W phase, and the W phase with the U phase. "2" indicates a fourth pattern in which the U phase is swapped with the W phase, the V phase with the U phase, and the W phase with the V phase. For example, node[0].stretching pattern=0 indicates that no twisting is performed at node N0. Also, node[2].stretching pattern=1 indicates that the U phase is swapped with the V phase, the V phase with the W phase, and the W phase with the U phase at node N2 (stretching in the third pattern). Also, node[5].stretching pattern=2 indicates that the U phase is swapped with the W phase, the V phase with the U phase, and the W phase with the V phase at node N5 (stretching in the fourth pattern). In addition, in the power system 20 that supplies three-phase AC power, the order of the phases cannot be changed, so the wiring pattern is limited to these three values.

[0049] Similarly, the variable "transformer reconnection pattern" takes three values, 0, 1, and 2, with "0" indicating that the connection phase of the pole transformer TR is not changed (no reconnection), "1" indicating the first pattern in which U phase is switched to V phase, V phase to W phase, and W phase to U phase, and "2" indicating the second pattern in which U phase is switched to W phase, V phase to U phase, and W phase to V phase. For example, Node[0].Transformer reconnection pattern=0 indicates that no reconnection is performed at node N0. Also, Node[3].Transformer reconnection pattern=1 indicates that the connection of the pole transformer TR is reconnected at node N3 so that U phase is switched to V phase, V phase to W phase, and W phase to U phase (reconnection in the first pattern). Also, node [4].transformer reconnection pattern=2 indicates that the pole transformer TR is reconnected at node N4 so as to switch the U phase to the W phase, the V phase to the U phase, and the W phase to the V phase (reconnection in the second pattern). Note that in power system 20 that supplies three-phase AC power, the order of the phases cannot be changed, so the transformer switching pattern is also limited to these three values.

[0050] First, when the power system 20 shown in FIG. 10 is racked using a combination of racking patterns shown in table T200, as in power system 20A shown in FIG. 11, at node N2, the U phase is connected to the V phase, the V phase is connected to the W phase, and the W phase is connected to the U phase, and at node N5, the U phase is connected to the W phase, the V phase is connected to the U phase, and the W phase is connected to the V phase.

[0051] The unbalance resolving unit 15 calculates the phase rotation at each node N after twisting using the variable "node[i].twisting pattern" as in table T300 shown in FIG. 11, and substitutes it for the variable "node[i].phase rotation". The variable "phase rotation" indicates how the phases are switched at each of the m nodes N when the transmission / distribution lines 22 are twisted using a combination of the generated twisting patterns. The variable "phase rotation", like the variable "twisting pattern", takes three values ​​of 0, 1, and 2, where "0" indicates that the state of the transmission / distribution line 22 does not change, "1" indicates that the U phase is switched to the V phase, the V phase is switched to the W phase, and the W phase is switched to the U phase, and "2" indicates that the U phase is switched to the W phase, the V phase is switched to the U phase, and the W phase is switched to the V phase. For example, in the node N3, the phase rotation is set to "1" because the U phase is replaced with the V phase, the V phase with the W phase, and the W phase with the U phase as a result of the crosslinking in the third pattern in the node N2. In addition, in the node N5, the phase rotation is set to "0" because the state of the power transmission / distribution line 22 does not change as a result of the node N2 being crosslinked in the third pattern and the node N5 being crosslinked in the fourth pattern.

[0052] Specifically, first, the imbalance resolution unit 15 sets the phase rotation of node N0 to 0 (node[0].phase rotation=0). Then, when i is 1 or more, the imbalance resolution unit 15 sets node[i].phase rotation to the remainder of node[i-1].phase rotation+node[i].twisted pattern modulo 3 (i.e., the remainder when divided by 3). In other words, the imbalance resolution unit 15 sets "node[i].phase rotation=node[i-1].phase rotation+node[i].twisted pattern%3". Here, "%" indicates a remainder.

[0053] Next, when the transformer connection switching is performed on the power system 20A after installation shown in Figure 11 using a combination of transformer connection switching patterns shown in table T200, the pole transformer TR that was connected to the WU phase at node N3 is connected to the UV phase, and the pole transformer TR that was connected to the WU phase at node N4 is connected to the VW phase, as shown in power system 20B shown in Figure 12.

[0054] The unbalance resolving unit 15 calculates the phase rotation at each node N after the transformer reconnection using the variable "node[i].transformer reconnection pattern" as in table T400 shown in Fig. 12, and substitutes it for the variable "node[i].phase rotation". For example, at node N3, as a result of the transformer reconnection in the first pattern, the connection phase changes from the WU phase to the UV phase, so "2" is set for the phase rotation. At node N4, as a result of the transformer reconnection in the second pattern, the connection phase does not change, so "0" is set for the phase rotation.

[0055] Specifically, the unbalance resolution unit 15 sets Node[i].phase rotation as the remainder of Node[i].phase rotation+Node[i].transformer connection switching pattern modulo 3 (i.e., the remainder when divided by 3). In other words, the unbalance resolution unit 15 sets "Node[i].phase rotation=Node[i].phase rotation+Node[i].transformer connection switching pattern%3".

[0056] In this embodiment, the unbalance eliminating unit 15 calculates the phase rotation after wiring and then calculates the phase rotation after the transformer connection is changed, but this is not limited to this, and the imbalance eliminating unit 15 may first calculate the phase rotation after the transformer connection is changed and then calculate the phase rotation after wiring.

[0057] Next, the unbalance resolution unit 15 uses the calculated phase rotation to calculate the load after the construction is performed according to the generated construction pattern p. Specifically, the unbalance resolution unit 15 assigns the load at each node N after the construction to the variable "node [i]. post-construction load setting [j]" according to the following equations (1) to (3).

[0058] Node[i].Post-construction load setting [(0 + Node[i].phase rotation)%3] = Node[i].Load setting [0]…(1)

[0059] Node[i].Post-construction load setting [(1 + Node[i].phase rotation)%3] = Node[i].Load setting [1]…(2)

[0060] Node[i].Post-construction load setting [(2 + Node[i].phase rotation)%3] = Node[i].Load setting [2]…(3)

[0061] The index of the array "load setting after construction" takes three values: 0, 1, and 2, with "0" indicating the UV phase, "1" indicating the VW phase, and "2" indicating the WU phase. For example, Node[i].load setting after construction "0" indicates the load of the UV phase after construction at node N with node number "i", Node[i].load setting after construction "1" indicates the load of the VW phase after construction at node N with node number "i", and Node[i].load setting after construction "2" indicates the load of the WU phase after construction at node N with node number "i".

[0062] Taking the load of node N2 as an example, a specific description will be given using the above-mentioned formula (1). The above-mentioned formula (1) at node N2 becomes the following formula (1A).

[0063] Node[2].Post-construction load setting [(0 + Node[2].phase rotation)%3] = Node[2].Load setting [0]...(1A)

[0064] Then, by substituting node[2].phase rotation=1 into equation (1A), the following equation (1B) can be obtained.

[0065] Node[2].Post-construction load setting[(0+1)%3] = Node[2].Load setting[0]…(1B)

[0066] As a result, the following equation (1C) is obtained, and it can be calculated that the load of the UV phase of node N2 is connected to the WU phase by the twisted connection.

[0067] Node[2].Post-construction load setting[1] = Node[2].Load setting[0]…(1C)

[0068] Then, by substituting node[2].load setting[0]=150.0 into equation (1C), the load on the VW phase of node N2 after installation can be calculated as shown in the following equation (1D).

[0069] Node[2].Post-construction load setting[1]=150.0…(1D)

[0070] In this way, by using equation (1), the fact that the load of the UV phase of node N2, "150.0", is changed to the VW phase due to construction can be set in the variable "post-construction load setting".

[0071] Then, the unbalance resolution unit 15 executes a simulation by three-phase power flow calculation using the variable "node [i]. post-construction load setting [j]" indicating the load after installation, and calculates the voltage and unbalance rate for each phase of each node N after construction in the generated construction pattern p. Specifically, the unbalance resolution unit 15 calculates the positive-sequence voltage and the negative-sequence voltage from the voltages of each of the three phases, and calculates the unbalance rate by multiplying the value obtained by dividing the negative-sequence voltage by the positive-sequence voltage by 100 (i.e., "negative-sequence voltage ÷ positive-sequence voltage × 100").

[0072] FIG. 13 is a schematic diagram showing an example of an unbalance rate calculation result table generated by the unbalance resolution unit 15. The unbalance resolution unit 15 generates an unbalance rate calculation result table including the calculated voltages and unbalance rates for each phase of each node N. For example, the unbalance resolution unit 15 writes the values ​​of the variables of the twisting pattern, the transformer reconnection pattern, the phase rotation, the load setting [0] to the load setting [2], the post-construction load setting [0] to the post-construction load setting [2], the voltage [0] to the voltage [2], and the unbalance rate for each of the m nodes N into the unbalance rate calculation result table. Here, the voltage [0] indicates the voltage of the UV phase, the voltage [1] indicates the voltage of the VW phase, and the voltage [2] indicates the voltage of the WU phase. FIG. 13 shows an example of data when construction is performed on the power system 20 according to the construction pattern shown in table T200. The unbalance resolution unit 15 generates an unbalance rate calculation result table for each combination of construction patterns. Furthermore, the unbalance resolution unit 15 generates an unbalance rate calculation result table for each of a plurality of time sections (for example, all time sections for each measurement cycle (for example, 30 minutes) of the watt-hour meter SM within a predetermined period).

[0073] Next, the unbalance resolution unit 15 calculates an objective function from the unbalance rate of the voltage of each of the n nodes N. For example, the unbalance resolution unit 15 calculates an objective function that selectively combines the average value of the unbalance rate of the voltage of each of the n nodes N (hereinafter, referred to as the "average unbalance rate", which is "1.07" in the case of the data example shown in FIG. 13), the maximum value of the unbalance rate of the voltage of each of the n nodes N (hereinafter, referred to as the "maximum unbalance rate", which is "1.95" in the case of the data example shown in FIG. 13), the number of nodes N that cross the transmission / distribution line 22 (hereinafter, referred to as the "number of crossings", which is "2" in the case of the data example shown in FIG. 13), and the number of nodes N that switch the transformer connection (hereinafter, referred to as the "number of transformer connection changes", which is "2" in the case of the data example shown in FIG. 13). In this embodiment, the unbalance resolution unit 15 calculates the objective function F(p) by the following formula (4).

[0074] F(p) = X×f(p) + Y×g(p) + Z1×h1(p) + Z2×h2(p) …(4)

[0075] Here, p is the construction pattern shown in the following equation (5). The construction pattern p is a decision variable.

[0076] p ∈ {x1, x2, , x m-1 , x m} , x i ∈ {0, 1, 2}…(5)

[0077] Here, m is the number of nodes N. Function f(p) is a function that takes construction pattern p as input and calculates the average unbalance rate of all nodes N at all time cross sections. Function g(p) is a function that takes construction pattern p as input and extracts the maximum unbalance rate from all nodes N at all time cross sections. Function h1(p) is a function that takes construction pattern p as input and counts the number of twisted racks. Function h2(p) is a function that takes construction pattern p as input and counts the number of transformer reconnections.

[0078] In addition, "X" is the weight of the average unbalance rate, "Y" is the weight of the maximum unbalance rate, "Z1" is the weight of the number of twists, and "Z2" is the weight of the number of transformer connection changes. By changing the values ​​of X, Y, Z1, and Z2, the weight of each element (average unbalance rate, maximum unbalance rate, number of twists, and number of transformer connection changes) can be changed. For example, by making the value of X larger than the values ​​of Y, Z1, and Z2, the weight of the average unbalance rate can be made heavier than the weights of the maximum unbalance rate, number of twists, and number of transformer connection changes. In other words, by making the value of X larger, the weight of the average unbalance rate can be made heavier, and by making the value of X smaller, the weight of the average unbalance rate can be made smaller. Similarly, by making the value of Y larger, the weight of the maximum unbalance rate can be made heavier, and by making the value of Y smaller, the weight of the maximum unbalance rate can be made smaller. Similarly, by making the value of Z1 larger, the weight of the number of twists can be made heavier, and by making the value of Z1 smaller, the weight of the number of twists can be made smaller. Similarly, by increasing the value of Z2, the weight of the number of transformer connection changes can be increased, and by decreasing the value of Z2, the weight of the number of transformer connection changes can be decreased. Also, by setting the values ​​of X, Y, Z1, and Z2 to 0, each element (average unbalance rate, maximum unbalance rate, number of twists, or number of transformer connection changes) can be excluded from the objective function. For example, by setting Z1 or Z2 to 0, the number of twists or number of transformer connection changes can be excluded from the objective function.

[0079] The imbalance resolving unit 15 may calculate the objective function F(p) by the following equation (6) instead of the above equation (4).

[0080] TIFF2025016222000002.tif7145

[0081] Here, the function f i (p) is a function that calculates the maximum average unbalance rate of all nodes N at time slice i by inputting construction pattern p. Also, g i(p) is a function that extracts the maximum unbalance rate from among all nodes N at the time cross section i using the construction pattern p as input. In this embodiment, the objective function is determined based on at least either the average unbalance rate or the maximum unbalance rate, but is not limited thereto, and may be determined based on the voltage unbalance rate of each of the n nodes N, such as the median of the voltage unbalance rate of each of the n nodes N.

[0082] Then, the unbalance resolution unit 15 determines constraint conditions for each element of the objective function (average unbalance rate, maximum unbalance rate, number of twists, or number of transformer connection changes) using preset thresholds α, β, γ1, and γ2. For example, the constraint condition for the average unbalance rate is that it is smaller than threshold α, the constraint condition for the maximum unbalance rate is that it is smaller than threshold β, the constraint condition for the number of twists is that it is smaller than threshold γ1, and the constraint condition for the number of transformer connections is that it is smaller than threshold γ2. Specifically, the unbalance resolution unit 15 determines the weight value of each element of the objective function as follows.

[0083] When f(p)<threshold α, X=A When f(p) ≧ threshold α, X=A′ (where A′≫A) Here, A and A' are preset constants, and A' is sufficiently larger than A.

[0084] When g(p)<threshold β, Y=B When g(p) ≧ threshold β, Y = B′ (where B′ ≫ B) Here, B and B' are preset constants. Also, B' is sufficiently larger than B.

[0085] When h1(p)<threshold γ1, Z1=C When h1(p) ≧ threshold γ1, Z1 = C′ (where C′ ≫ C) Here, C and C' are preset constants, and C' is sufficiently larger than C.

[0086] When h2(p)<threshold γ2, Z1=D When h2(p) ≧ threshold γ2, Z1 = D′ (where D′≫D) Here, D and D' are preset constants, and D' is sufficiently larger than D.

[0087] By determining the weighting value for each element of the objective function in this way, it is possible to prevent a construction pattern that does not satisfy each constraint condition from being selected as a construction pattern that reduces the unbalance rate. For example, if the threshold value γ1 is set to 2, in the data example shown in Figure 14 described later, No. 3 and No. 5, which have two or more racks, will not be selected as a construction pattern that reduces the unbalance rate because the objective function has a very large value.

[0088] After that, the imbalance resolving unit 15 changes the construction pattern and calculates the objective function for the changed construction pattern until the termination condition is satisfied. The termination condition is, for example, that the number of construction patterns (the number of calculated objective functions) exceeds a predetermined threshold, or that the value of the calculated objective function is smaller than a predetermined threshold. The termination condition can be defined arbitrarily.

[0089] FIG. 14 is a schematic diagram showing an example of an objective function calculation result table generated by the imbalance resolving unit 15. As shown in FIG. Each time the unbalance resolution unit 15 calculates an objective function, it writes in an objective function calculation result table a number that identifies the construction pattern, the average unbalance rate (unit: %), the maximum unbalance rate (unit: %), the number of twisted units, the number of transformer reconnections, and the calculated objective function in association with each other.

[0090] Then, when the termination condition is satisfied, the imbalance resolution unit 15 optimizes the objective function. Specifically, the imbalance resolution unit 15 refers to the objective function calculation result table and selects the construction pattern with the smallest objective function (i.e., min F(p)) as the construction pattern that reduces the unbalance rate. For example, in the illustrated data example, the imbalance resolution unit 15 selects construction pattern No. 4 with the smallest objective function as the construction pattern that reduces the unbalance rate. Then, the imbalance resolution unit 15 outputs data indicating the selected construction pattern (hereinafter referred to as the "determination result") to the result output unit 16.

[0091] The result output unit 16 outputs the determination result input from the imbalance resolution unit 15 by displaying it on a display or printing it on a printer. The result output unit 16 may transmit the determination result to another computer or the like via the network connection unit 107.

[0092] ==An example of an imbalance resolution process executed by the information processing device 10== FIG. 15 is a flowchart showing an example of an imbalance resolution process for the power system 20, which is executed by the information processing device 10. First, the data generating unit 14 generates input data based on the system configuration information, the auxiliary device information, and the transformer power data (step S100). Then, the unbalance eliminating unit 15 reads the input data generated by the data generating unit 14 (step S200). Then, the unbalance eliminating unit 15 executes a simulation using a three-phase power flow calculation based on the input data, and calculates the voltage for each phase at each node N (step S300). Next, the unbalance eliminating unit 15 calculates the current unbalance rate of each node N based on the calculated voltage for each phase at each node N (step S400).

[0093] Next, the imbalance resolution unit 15 determines whether or not an imbalance measure is necessary based on the calculated imbalance rate of each node N (step S500). For example, the imbalance resolution unit 15 determines that an imbalance measure is necessary when the average imbalance rate, the maximum imbalance rate, or both of the average and maximum imbalance rates of each node N calculated in step S400 exceed preset thresholds. When it is determined that an imbalance measure is not necessary (step S500: No), the information processing device 10 ends this imbalance resolution process.

[0094] On the other hand, if it is determined that an imbalance solution is necessary (step S500: Yes), the imbalance resolution unit 15 executes a decision process shown in steps S601 to S605 (step S600).

[0095] In the determination process, the imbalance resolving unit 15 first changes the construction pattern p (step S601).

[0096] Next, for each of the multiple time slices t, the unbalance resolution unit 15 executes a simulation by three-phase power flow calculation using the load at each time slice t, and calculates the voltage unbalance rate at each node N when construction is performed according to the changed construction pattern (step S602: calculation step). That is, the unbalance resolution unit 15 repeatedly executes the process of step S602 for all the loads at the multiple time slices t.

[0097] Next, the imbalance resolution unit 15 calculates the above-mentioned objective function based on the imbalance rate of each node N (step S603). After that, the imbalance resolution unit 15 determines whether the above-mentioned termination condition is satisfied (step S604).

[0098] If it is determined that the termination condition is not satisfied (step S604: No), the process returns to step S601. That is, the imbalance resolving unit 15 changes the construction pattern and repeats the processes of steps S602 to S603 until the termination condition is satisfied.

[0099] On the other hand, if it is determined that the termination condition is satisfied (step S604: Yes), the imbalance resolution unit 15 outputs the construction pattern that minimizes the objective function as the determination result to the result output unit 16 (step S605: determination step). The result output unit 16 outputs the determination result by displaying it on a display or printing it on a printer. Thereafter, the information processing device 10 terminates this imbalance resolution process.

[0100] ==Effects== The effects of the imbalance resolution process in this embodiment will be described below with reference to Fig. 16 to Fig. 19. In Fig. 16 to Fig. 19, the parts indicated by black squares indicate nodes N.

[0101] 16 is a diagram showing the distribution of annual maximum unbalance rates in power system 20 before construction. As shown in the figure, in power system 20, the maximum unbalance rate of each node N in section A0 closest to distribution substation 21 is less than 1.5%, whereas in section B0 farther from distribution substation 21 than section A0, the maximum unbalance rate of each node N is 1.5% or more and less than 3.0%, and in section C0 farther from distribution substation 21 than section B0, the maximum unbalance rate of each node N is 3.0 or more.

[0102] Fig. 17 is a diagram showing the distribution of the annual maximum unbalance rate in the power system 20 after construction using the construction method determined by the determination process. In this example, the unbalance resolution unit 15 has determined, by the above-mentioned determination process, a construction method for the power system 20 shown in Fig. 16 in which cross-connection is performed at two nodes N and a transformer connection is changed at one node N. As shown in the figure, in the power system 20 after construction using the construction method determined by the determination process, the maximum unbalance rate of each node N has been improved to less than 1.5% in all sections A1.

[0103] FIG. 18 is a diagram showing the distribution of the annual maximum unbalance rate in the power system 20 after construction in the state of transformer connection switching determined by the determination process. In this example, the unbalance resolution unit 15 has determined a construction method for the power system 20 shown in FIG. 16 by setting all the variables "node[n].racking pattern" to "0" in the above-mentioned determination process, and performing transformer connection switching at six nodes N without racking. In this way, by setting all the variables "node[n].racking pattern" to "0", it is possible to determine a construction method of only transformer connection switching without racking (i.e., only the state of the connection phase where the pole transformer is connected to the three-phase transmission and distribution line). In other words, the unbalance resolution unit 15 can exclude racking from the construction methods by setting all the variables "node[n].racking pattern" to "0". As shown in the figure, in the power system 20 after the work to change the transformer connection to the state determined by the determination process, the maximum unbalance rate of each node N in section A2 has improved to less than 1.5%, and in section B2, which is farther from the distribution substation 21 than section A2, the maximum unbalance rate of each node N has improved to 1.5% or more and less than 3.0. However, with the work method of only transformer connection change, the number of works is three more and the unbalance improvement rate is lower than with the work method of both racking and transformer connection change.

[0104] FIG. 19 is a diagram showing the distribution of the annual maximum unbalance rate in the power system 20 after construction in the twisted state determined by the determination process. In this example, the unbalance resolution unit 15 has determined a construction method for twisting four nodes N without transformer reconnection by setting all the variables "node [n]. transformer reconnection pattern" to "0" in the above-mentioned determination process for the power system 20 shown in FIG. 16. In this way, by setting all the variables "node [n]. transformer reconnection pattern" to "0", it is possible to determine a construction method of twisting only without transformer reconnection (i.e., only the state of the three-phase transmission and distribution line at each of the m nodes). In other words, the unbalance resolution unit 15 can exclude transformer reconnection from the construction method by setting all the variables "node [n]. transformer reconnection pattern" to "0". As shown in the figure, in the power system 20 after construction in the twisted state determined by the determination process, the maximum unbalance rate of each node N is improved to less than 1.5% in all sections A3. The construction method that only involves racking has the same unbalance improvement rate as the construction method that involves both racking and transformer reconnection, but the number of construction works is one more.

[0105] In this way, the construction method of performing both the twisting and the transformer reconnection determined by the determination process can reduce the number of construction works (i.e., construction costs) compared to the construction method of only twisting or only transformer reconnection. When an imbalance occurs over a wide area, twisting can effectively eliminate the imbalance with less construction work. On the other hand, in the case of a power system in which localized imbalances are scattered, twisting can effectively eliminate the imbalance with less construction work by performing transformer reconnection at the point where the imbalance occurs rather than twisting. Therefore, by using the two measures of twisting and transformer reconnection, the imbalance can be effectively eliminated with less construction work without being aware of the characteristics of the power system. For example, in a power system in which a wide-area imbalance occurs, applying not only twisting but also transformer reconnection to the localized imbalance parts can achieve a greater imbalance improvement effect than twisting alone.

[0106] In this manner, the information processing device 10 of this embodiment calculates the unbalance rate when construction is performed for each construction pattern by simulation based on the system configuration information and the actual measurement value of the watt-hour meter SM, and determines the construction pattern in which the objective function determined based on the unbalance rate is the smallest as the construction method for eliminating the unbalance rate. As a result, the information processing device 10 of this embodiment can automatically determine a construction method (the state of the rack and the state of the transformer reconnection) that effectively improves the unbalance rate of the power system 20. Therefore, it becomes possible to effectively improve the unbalance rate of the power system 20.

[0107] ===== Second embodiment ===== Next, a second embodiment of the present invention will be described. This embodiment differs from the first embodiment in that a construction pattern that reduces the unbalance rate is determined by using a combinatorial optimization method using metaheuristics. The hardware configuration and functional configuration of the information processing device 10 are the same as those of the first embodiment, and therefore the description thereof will be omitted.

[0108] Fig. 20 is a flowchart showing an example of an imbalance resolution process for the power system 20 executed by the information processing device 10 according to this embodiment. In the example shown in this figure, the information processing device 10 uses a genetic algorithm as a combinatorial optimization method using metaheuristics. The processes shown in steps S100 to S500 in this figure are similar to those in the first embodiment, and therefore their description will be omitted. In this embodiment, the decision process (step S610) shown in steps S611 to S617 differs from the decision process (step S600) shown in the first embodiment.

[0109] In the determination process, the imbalance resolution unit 15 first generates an initial group (n, p) having different construction patterns p (step S611).

[0110] Next, the imbalance resolution unit 15 executes the processes of the following steps S612 to S613 for each of the multiple construction patterns p included in the generated population. That is, the processes of steps S612 to S613 are repeatedly executed the number of times equal to the number n of construction patterns included in the population.

[0111] The unbalance resolution unit 15 executes a simulation by three-phase power flow calculation using the load at each of the multiple time slices t, and calculates the voltage unbalance rate at each node N when the construction pattern p is applied (step S612: calculation step). That is, the unbalance resolution unit 15 repeatedly executes the process of step S612 for all the loads at the multiple time slices t.

[0112] Next, the imbalance resolution unit 15 calculates an objective function based on the imbalance rate of each node N at all time slices t (step S613). Here, the imbalance resolution unit 15 calculates an objective function for each of all construction patterns included in the generated population.

[0113] After that, the imbalance resolution unit 15 performs genetic operations such as crossover, mutation, or selection on the generated population (step S614).

[0114] After that, the imbalance resolving unit 15 determines whether or not the above-mentioned termination condition is satisfied (step S615).

[0115] If it is determined that the termination condition is not satisfied (step S615: No), a new generation is generated by the genetic operation performed in step S614, the populations are replaced (step S616), and the process returns to step S612. That is, the imbalance resolution unit 15 replaces the populations and repeats the processes of steps S612 to S614 until the termination condition is satisfied.

[0116] On the other hand, if it is determined that the termination condition is satisfied (step S615: Yes), the imbalance resolution unit 15 outputs the construction pattern that minimizes the objective function as the determination result to the result output unit 16 (step S617: determination step). The result output unit 16 outputs the determination result by displaying it on a display or printing it on a printer. Thereafter, the information processing device 10 terminates the imbalance resolution process.

[0117] In this embodiment, a genetic algorithm is used as an example of a combinatorial optimization method using metaheuristics. However, the present invention is not limited to this, and other methods such as particle swarm optimization or tabu search can also be applied.

[0118] =====Third embodiment===== Next, a third embodiment of the present invention will be described. In the first and second embodiments, the load distribution of each node N is calculated based on the measurement value of the power meter SM. However, in this embodiment, the load distribution is calculated using the measurement value of the sensor-integrated switch 23, which is different from the first and second embodiments.

[0119] FIG. 21 is a configuration diagram showing an example of functions and databases provided in the information processing device 10A according to this embodiment. In this diagram, the same components as those in the information processing device 10 according to the first embodiment are given the same reference numerals, and their description will be omitted. Also, since the hardware configuration of the information processing device 10A is similar to that of the first embodiment, its description will be omitted. The information processing device 10A according to this embodiment includes a sensor switch measurement database 17 in addition to the configuration of the information processing device 10 according to the first embodiment. The sensor switch measurement database 17 is pre-stored in the memory unit 105 of the information processing device 10A.

[0120] The sensor switch measurement database 17 is a database that stores a sensor measurement value table indicating periodic measurement values ​​measured by the sensor-embedded switch 23. The measurement values ​​of the sensor-embedded switch 23 include at least the voltage and current at the installation point. The data stored in the sensor measurement value table may be stored in advance in the storage unit 105, or may be updated as needed by the CPU 101 acquiring the measurement values ​​from the sensor-embedded switch 23 via the communication line 30 and writing the acquired measurement values ​​to the sensor measurement value table.

[0121] 22 is a schematic diagram showing a data configuration and an example of data in a sensor measurement table. As shown in the figure, the sensor measurement table has items such as a sensor-embedded switch ID, a measurement date and time, a voltage Vuv, a voltage Vvw, a voltage Vwu, a current Iu0, a current Iv0, a current Iw0, a power factor u, a power factor v, and a power factor w.

[0122] The sensor-embedded switch ID is an accessory device ID that identifies the sensor-embedded switch 23. The measurement date and time is the date and time (year, month, day, hour, minute) when the measurement values ​​(voltage Vuv, voltage Vvw, voltage Vwu, current Iu0, current Iv0, current Iw0, power factor u, power factor v, and power factor w) were measured. The voltage Vuv is the voltage of the UV phase (unit: V (volts)). The voltage Vvw is the voltage of the VW phase. The voltage Vwu is the voltage of the WU phase. The current Iu0 is the current (unit: A (amperes)) flowing through the U phase. The current Iv0 is the current flowing through the V phase. The current Iw0 is the current flowing through the W phase. The power factor u is the power factor of the U phase. The power factor v is the power factor of the V phase. The power factor w is the power factor of the W phase. In the illustrated example, the measurement value table stores the measurement value of the sensor-embedded switch 23 every minute. That is, in this example, the sensor-embedded switch 23 measures the measurement value at a fixed cycle of every minute.

[0123] The data generating unit 14A estimates the load distribution at each node N based on the information stored in the system configuration database 11 and the sensor measurement value table, and generates input data based on the estimated load distribution. For example, the data generating unit 14A performs a three-phase power flow calculation by changing the average power consumption of each pole transformer TR (or the amount of power used by each consumer) so that it matches the measurement value of the sensor-integrated switch 23. As a result, the data generating unit 14A can estimate the load distribution at each node N.

[0124] In the present embodiment, the information processing device 10A estimates the load distribution at each node N using only the measurement value of the sensor-embedded switch 23, but the present invention is not limited thereto, and the load distribution at each node N may be estimated using both the measurement value of each watt-hour meter SM and the measurement value of the sensor-embedded switch 23. In general, the measurement period of the watt-hour meter SM (e.g., 30 minutes) is longer than the measurement period of the sensor-embedded switch 23 (e.g., 1 minute). Therefore, the information processing device 10A can estimate the load distribution of each node N in a period shorter than the measurement period of the watt-hour meter SM by using the measurement value of the sensor-embedded switch 23 in addition to the measurement value of each watt-hour meter SM. This allows the information processing device 10A to accurately estimate the load distribution of each node N in a time series. That is, the information processing device 10A can generate the load distribution of each node N in a finer time section.

[0125] =====Summary===== The information processing device 10 of the present invention has been described above. The information processing device 10 of the present invention calculates the voltage unbalance rate of each of the n nodes N based on a plurality of combinations obtained as a first state in which the state of the connection phase in which the pole transformer TR in each of the m nodes in the power system 20 is connected to the transmission / distribution line 22 is not changed, a second state in which the state is changed in a first pattern, or a third state in which the state is changed in a second pattern different from the first pattern, the power exchanged with the power system 20 in each of the n nodes N, and system configuration information indicating the configuration of the power system 20, and determines the state of the connection phase in which the pole transformer TR in each of the m nodes N is connected based on the calculation result of the voltage unbalance rate.

[0126] With this configuration, the information processing device 10 according to the present invention can determine a construction method capable of improving the voltage unbalance rate of the power transmission / distribution line 22 with high accuracy.

[0127] In addition, the information processing device 10 according to the present invention determines the state of the connection phase to which the pole transformer TR is connected at each of the m nodes N as a decision variable, and determines the state of the connection phase to which the pole transformer TR is connected at each of the m nodes N by using an objective function determined based on the voltage unbalance rate of each of the n nodes N.

[0128] With this configuration, the information processing device 10 according to the present invention can determine a construction method that optimizes (eg, minimizes) the voltage unbalance rate of each of the n nodes.

[0129] Moreover, the information processing device 10 according to the present invention determines the state of the connection phase to which the pole transformer TR is connected at each of the m nodes, using an objective function determined based on the number of pole transformers TR for which the connection phase is changed.

[0130] With this configuration, the information processing device 10 according to the present invention can determine a construction method that optimizes the number of pole transformers TR that change the connection phase (for example, the number of pole transformers TR that change the connection phase is small). For example, by determining a construction method that reduces the number of pole transformers TR that change the connection phase, construction costs can be reduced.

[0131] Moreover, the information processing device 10 according to the present invention determines the state of the connection phase to which the pole transformer TR is connected at each of the m nodes N under the constraint condition for the voltage unbalance rate of each of the n nodes N.

[0132] With this configuration, the information processing device 10 according to the present invention can determine a construction method that satisfies the constraint condition for the voltage unbalance rate of each of the n nodes. For example, if the constraint condition is "the average value of the voltage unbalance rate or the maximum value of the voltage unbalance rate is smaller than a predetermined threshold value," a construction method in which the average value of the voltage unbalance rate or the maximum value of the voltage unbalance rate is equal to or greater than the threshold value will not be determined.

[0133] Moreover, the information processing device 10 according to the present invention determines the state of the connection phase to which the pole transformer TR is connected in each of the m nodes under a constraint on the number of pole transformers TR for which the connection phase is changed.

[0134] With this configuration, the information processing device 10 according to the present invention can determine a construction method that satisfies the constraint on the number of pole transformers TR that change the connection phase. For example, if the constraint is that "the number of pole transformers TR that change the connection phase is less than a predetermined threshold value," a construction method in which the number of pole transformers TR that change the connection phase is equal to or greater than the predetermined threshold value will not be determined.

[0135] Moreover, the information processing device 10 according to the present invention optimizes an objective function by a combinatorial optimization method using metaheuristics, and determines the state of the connection phase to which the pole transformer TR is connected in each of the m nodes N.

[0136] With this configuration, it is possible to reduce calculation costs and determine a construction method that reduces the unbalance rate efficiently and accurately.

[0137] Furthermore, the information processing device 10 of the present invention calculates a voltage unbalance rate for each of the n nodes N based on a plurality of combinations obtained by setting the state of the transmission / distribution line 22 at each of the m nodes in the power system 20 as either a fourth state in which the line is not spanned, a fifth state in which the line is spanned in a third pattern, or a sixth state in which the line is spanned in a fourth pattern different from the third pattern, a plurality of combinations obtained by setting the state of the connection phase in which the pole transformer TR at each of the m nodes in the power system 20 is connected to the transmission / distribution line 22 as either a first state in which the state is not changed, a second state in which the state is changed in the first pattern, or a third state in which the state is changed in the second pattern different from the first pattern, power exchanged with the power system 20 at each of the n nodes N, and system configuration information indicating the configuration of the power system 20, and determines the state of the transmission / distribution line 22 at each of the m nodes N and the state of the connection phase to which the pole transformer TR is connected, based on the calculation result of the voltage unbalance rate.

[0138] With this configuration, the information processing device 10 according to the present invention can determine a construction method (the state of the twisting and the state of the transformer reconnection) capable of improving the voltage unbalance rate of the power transmission / distribution line 22 with high accuracy.

[0139] In addition, the information processing device 10 according to the present invention determines the state of the transmission / distribution line 22 at each of the m nodes N and the state of the connection phase to which the pole transformer TR is connected, as decision variables, and determines the state of the transmission / distribution line 22 at each of the m nodes N and the state of the connection phase to which the pole transformer TR is connected, using an objective function determined based on the voltage unbalance rate of each of the n nodes N.

[0140] With this configuration, the information processing device 10 according to the present invention can determine a construction method that optimizes (eg, minimizes) the voltage unbalance rate of each of the n nodes.

[0141] In addition, the information processing device 10 according to the present invention determines the state of the transmission / distribution line 22 at each of the m nodes and the state of the connection phase to which the pole transformer TR is connected, using an objective function determined based on the number of nodes N across which the transmission / distribution line 22 is spanned.

[0142] With this configuration, the information processing device 10 according to the present invention can determine a racking state that optimizes the number of racked nodes N (for example, a small number of racked nodes N). For example, by determining a construction method that reduces the number of racks, construction costs associated with racking can be reduced.

[0143] Moreover, the information processing device 10 according to the present invention determines the state of the power transmission / distribution line 22 and the state of the connection phase to which the pole transformer TR is connected at each of the m nodes N under constraints on the voltage unbalance rate of each of the n nodes N.

[0144] With this configuration, the information processing device 10 according to the present invention can determine a construction method that satisfies the constraint on the average value of the voltage unbalance rate of each of the n nodes. For example, if the constraint is that "the average value of the voltage unbalance rate or the maximum value of the voltage unbalance rate is smaller than a predetermined threshold value," a construction method in which the average value of the voltage unbalance rate or the maximum value of the voltage unbalance rate is equal to or greater than the threshold value will not be determined.

[0145] Moreover, the information processing device 10 according to the present invention determines the state of the power transmission / distribution line 22 and the state of the connection phase to which the pole transformer TR is connected at each of the m nodes under a constraint on the number of nodes N across which the power transmission / distribution line 22 is spanned.

[0146] With this configuration, the information processing device 10 according to the present invention can determine a construction method that satisfies the constraint on the number of nodes N that cross the power transmission / distribution line 22. For example, if the constraint is that "the number of nodes N that cross the power transmission / distribution line 22 is less than a predetermined threshold value," a construction method in which the number of nodes N that cross the power transmission / distribution line 22 is equal to or greater than the predetermined threshold value will not be determined.

[0147] In addition, the information processing device 10 according to the present invention optimizes an objective function by a combinatorial optimization method using metaheuristics, and determines the state of the power transmission / distribution line 22 at each of the m nodes N and the state of the connection phase to which the pole transformer TR is connected.

[0148] With this configuration, it is possible to reduce calculation costs and determine a construction method that reduces the unbalance rate efficiently and accurately.

[0149] In addition, the information processing device 10 according to the present invention calculates the power exchanged with the power system 20 at each of the n nodes N using at least one of the measurement values ​​of a sensor-embedded switch 23 that measures the voltage and current at a predetermined position in the power system 20, or the measurement values ​​of a power meter SM connected to each of the n nodes N.

[0150] With this configuration, the information processing device 10 according to the present invention can generate a load distribution that reflects the actual load fluctuation or power generation fluctuation at each node N, using the measurement values ​​of the sensor-integrated switch 23 or each watthour meter SM.

[0151] The above-mentioned embodiment is for the purpose of facilitating understanding of the present invention, and is not intended to limit the present invention. Furthermore, the present invention can be modified or improved without departing from the spirit of the present invention, and it goes without saying that the present invention includes equivalents thereof.

[0152] For example, in the above-described embodiment, the information processing device 10 has been described as including both racking and transformer connection replacement as a construction method, but this is not limited thereto, and the information processing device 10 may determine a construction method of racking only, or a construction method of transformer connection replacement only. For example, the information processing device 10 can determine a construction method of racking only by setting all variables "node[n].transformer connection replacement pattern" to "0". Similarly, the information processing device 10 can determine a construction method of transformer connection replacement only by setting all variables "node[n].rack pattern" to "0".

[0153] In addition, each data stored in the above-mentioned system configuration database 11, smart meter information database 12, or sensor switch measurement database 17 may be read by the CPU 101 via the recording medium drive unit 106 as data stored in the recording medium 6, or may be obtained from an external computer or server via the network connection unit 107.

[0154] In addition, various data generated by each function of the information processing device 10, 10A, such as the above-mentioned transformer power data, the unbalance rate calculation result table for each construction pattern, or the objective function calculation result table, may be stored in the memory unit 105 by the CPU 101, may be written to the recording medium 6 via the recording medium drive unit 106, may be stored as a structure on the memory 102, or may be output to the output unit 104 together with the calculated decision result. [Explanation of symbols]

[0155] 10, 10A Information processing device 11 Power System Configuration Database 12 Smart Meter Information Database 13 Transformer power calculation section 14,14A Data Generation Section 15 Unbalance Elimination Section 16 Result output section 17 Sensor switch measurement database 101 CPU 102 Memory 103 Input section 104 Output section 105 Storage section 106 Recording medium drive unit 107 Network connection 20 Power system 21 Distribution substation 211 Transformer 212 Circuit Breaker 22 Transmission and distribution lines 23 Sensor-embedded switch 30 Communication lines N-node SM electricity meter TR Pole Transformer

Claims

1. a calculation unit that calculates a voltage unbalance rate of each of the n nodes based on a plurality of combinations obtained as a first state in which a state of a connection phase in which a pole transformer in each of m nodes in the power system is connected to a three-phase transmission / distribution line is not changed, a second state in which a state is changed in a first pattern, or a third state in which a state is changed in a second pattern different from the first pattern, power exchanged with the power system at each of the n nodes, and system configuration information indicating a configuration of the power system; a determination unit that determines a state of a connection phase to which the pole transformer is connected at each of the m nodes based on a calculation result of the voltage unbalance rate; An information processing device comprising:

2. 2. The information processing device according to claim 1, The determination unit is The state of the connection phase to which the pole transformer is connected at each of the m nodes is set as a decision variable, and the state of the connection phase to which the pole transformer is connected at each of the m nodes is determined using an objective function determined based on the voltage unbalance rate of each of the n nodes. Information processing device.

3. 3. The information processing device according to claim 2, The determination unit is The state of the connection phase to which the pole transformer is connected at each of the m nodes is determined using the objective function determined based on the number of the pole transformers for which the connection phase is changed. Information processing device.

4. 3. The information processing device according to claim 2, The determination unit is Determine the state of the connection phase to which the pole transformer is connected at each of the m nodes under a constraint on the voltage unbalance rate of each of the n nodes. Information processing device.

5. 4. The information processing device according to claim 3, The determination unit is Determine the state of the connection phase to which the pole transformer is connected at each of the m nodes under a constraint on the number of the pole transformers that change the connection phase. Information processing device.

6. 3. The information processing device according to claim 2, The determination unit is The objective function is optimized by a combinatorial optimization method using metaheuristics, and the state of the connection phase to which the pole transformer is connected at each of the m nodes is determined. Information processing device.

7. 7. The information processing device according to claim 1, The calculation unit is calculating a voltage unbalance rate for each of the n nodes based on a plurality of combinations obtained by setting a state of a three-phase transmission / distribution line at each of the m nodes in the power system as any one of a fourth state in which the line is not crossed, a fifth state in which the line is crossed in a third pattern, or a sixth state in which the line is crossed in a fourth pattern different from the third pattern, a plurality of combinations obtained by setting a state of a connection phase in which a pole transformer at each of the m nodes in the power system is connected to a three-phase transmission / distribution line as any one of a first state in which the connection phase is not changed, a second state in which the connection phase is changed in a first pattern, or a third state in which the connection phase is changed in a second pattern different from the first pattern, power exchanged with the power system at each of the n nodes, and the system configuration information; The determination unit determines a state of the three-phase transmission / distribution line and a state of the connection phase to which the pole transformer is connected at each of the m nodes based on a calculation result of the voltage unbalance rate. Information processing device.

8. The information processing device according to claim 7, The determination unit is The state of the three-phase transmission / distribution line at each of the m nodes and the state of the connection phase to which the pole transformer is connected are set as decision variables, and the state of the three-phase transmission / distribution line at each of the m nodes and the state of the connection phase to which the pole transformer is connected are determined using an objective function determined based on the voltage unbalance rate of each of the n nodes. Information processing device.

9. 9. The information processing device according to claim 8, The determination unit is Using the objective function determined based on the number of nodes that span the three-phase transmission / distribution line, a state of the three-phase transmission / distribution line and a state of the connection phase to which the pole transformer is connected at each of the m nodes are determined. Information processing device.

10. 9. The information processing device according to claim 8, The determination unit is Determine the state of the three-phase transmission / distribution line and the state of the connection phase to which the pole transformer is connected at each of the m nodes under a constraint condition for the voltage unbalance rate of each of the n nodes. Information processing device.

11. The information processing device according to claim 9, The determination unit is Under a constraint on the number of nodes that span the three-phase transmission / distribution line, a state of the three-phase transmission / distribution line and a state of the connection phase to which the pole transformer is connected are determined at each of the m nodes. Information processing device.

12. 9. The information processing device according to claim 8, The determination unit is The objective function is optimized by a combinatorial optimization method using metaheuristics, and the state of the three-phase transmission / distribution line and the state of the connection phase to which the pole transformer is connected at each of the m nodes are determined. Information processing device.

13. 2. The information processing device according to claim 1, The calculation unit is Calculating power exchanged with the power system at each of the n nodes using at least one of the measurement values ​​of a sensor that measures voltage and current at a predetermined position in the power system and the measurement values ​​of a smart meter connected to each of the n nodes. Information processing device.

14. An information processing device, a calculation step of calculating a voltage unbalance rate of each of the n nodes based on a plurality of combinations of a state of a connection phase in which a pole transformer in each of m nodes in the power system is connected to a three-phase transmission / distribution line, the combination being one of a first state in which the state is not changed, a second state in which the state is changed in a first pattern, or a third state in which the state is changed in a second pattern different from the first pattern, power exchanged with the power system in each of the n nodes, and system configuration information indicating a configuration of the power system; a determination step of determining a state of the connection phase to which the pole transformer is connected at each of the m nodes based on a result of the calculation of the voltage unbalance rate; An information processing method comprising:

15. On the computer, a calculation process for calculating a voltage unbalance rate of each of the n nodes based on a plurality of combinations obtained as a state of a connection phase in which a pole transformer in each of m nodes in the power system is connected to a three-phase transmission / distribution line, the state being one of a first state in which the connection phase is not changed, a second state in which the connection phase is changed in a first pattern, or a third state in which the connection phase is changed in a second pattern different from the first pattern, power exchanged with the power system in each of the n nodes, and system configuration information indicating a configuration of the power system; A determination process for determining a state of the connection phase to which the pole transformer is connected at each of the m nodes based on a calculation result of the voltage unbalance rate; A program that executes the following.

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