Connection phase estimation device, connection phase estimation program, and connection phase estimation method

Abstract

To estimate a connection phase of a transformer more accurately.SOLUTION: A connection phase estimation device acquires first line voltage data indicating line voltage between a first phase and a second phase of a three-phase AC output by a substation, second line voltage data indicating a line voltage between the second phase and a third phase of the three-phase AC output by the substation, third line voltage data indicating a line voltage data between the third phase and the first phase of the three-phase AC output by the substation, and transformer voltage data indicating a line voltage of a single-phase transformer, and estimates a connection phase to which the single-phase transformer is connected, among the first phase, second phase, and third phase of the three-phase AC output by the substation, based on at least one of correlation between the line voltage indicated by the first line voltage data and the line voltage indicated by the transformer voltage data, correlation between the line voltage indicated by the second line voltage data and the line voltage indicated by the transformer voltage data, and correlation between the line voltage indicated by the third line voltage data and the line voltage indicated by the transformer voltage data.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a connection phase estimation device, a connection phase estimation program, and a connection phase estimation method. [Background technology]

[0002] In recent years, the installation of distributed power sources such as solar panels has been increasing. In a three-phase, three-wire distribution line, each piece of equipment is connected so that the first phase current, the second phase current, and the third phase current are in balance with each other. This state is called three-phase balance.

[0003] However, if a distributed power source is connected to a specific phase out of these three phases and a reverse current is fed from the distributed power source to the distribution line, the current in the first phase, the current in the second phase, and the current in the third phase may not be balanced with each other. This condition is called three-phase unbalance. If a voltage unbalance occurs due to three-phase unbalance, it may cause malfunctions in the equipment of consumers receiving power from the distribution line.

[0004] For this reason, in order to avoid a situation where a voltage imbalance occurs, electric power utilities need to manage the connection phases of single-phase transformers to which distributed power sources are connected. On the other hand, since the number of single-phase transformers is huge and distribution lines may be twisted, it is very difficult for on-site workers to visually check the connection phases of single-phase transformers one by one. Under these circumstances, a technology has been developed to determine the connection phases of single-phase transformers by analyzing the correlation between the amount of power used by each consumer measured by a smart meter, which is rapidly becoming widespread, and the first phase current, second phase current, and third phase current of a three-phase AC measured by a sensor-embedded switch. An example of such a technology is a connection phase estimation device described in Patent Document 1.

[0005] This connection phase estimation device includes a calculation unit and a determination unit. The calculation unit calculates a correlation evaluation value between an amount of power measured by a measurement device under a second distribution line connected to any two of the three or more first distribution lines and each of the line currents of the three or more first distribution lines by applying a suppression amount according to the magnitude of the spectrum of each frequency component to the correlation value between the amount of power and each of the line currents in each frequency component. The determination unit determines the connection phase of the second distribution line based on the multiple correlation evaluation values ​​calculated by the calculation unit. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2017-32357 A

[0007] However, in this connection phase estimation device, the relationship between the amount of power measured by the measuring device and each line current is affected by the power factor, which results in insufficient accuracy in the correlation evaluation value, and may result in an erroneous determination of the connection phase of the single-phase transformer to which the single-phase transformer is connected. Summary of the Invention [Problem to be solved by the invention]

[0008] Therefore, an object of the present invention is to provide a connection phase estimation device, a connection phase estimation program, and a connection phase estimation method that are capable of estimating the connection phase of a transformer with higher accuracy. [Means for solving the problem]

[0009] One aspect of the present invention is data showing a first-phase current flow, a second-phase current flow, and a third-phase current flow for a first phase, a second phase, and a third phase of a three-phase AC output from a substation, the data including: and The magnitude of the forward current from the third phase, or the first phase, the second phase and The magnitude of the reverse power flow to the third phase is shown in the power flow data. If a first condition is satisfied that is less than or equal to a predetermined threshold, Or the reverse power flow is below a certain threshold. The second condition is metin the case where, first line voltage data indicating a line voltage between a first phase and a second phase, second line voltage data indicating a line voltage between a second phase and a third phase of a three-phase AC outputted by the substation, and third line voltage data indicating a line voltage between a third phase and a first phase of the three-phase AC outputted by the substation and and a connection phase estimation unit that estimates a connection phase to which the single-phase transformer is connected, among a first phase, a second phase, and a third phase of a three-phase AC output from the substation, based on at least one of a correlation between the line voltage indicated by the first line voltage data and the line voltage indicated by the transformer voltage data, a correlation between the line voltage indicated by the second line voltage data and the line voltage indicated by the transformer voltage data, and a correlation between the line voltage indicated by the third line voltage data and the line voltage indicated by the transformer voltage data.

[0010] In the above-described connected phase estimation device, the power flow data includes forward power flow data indicating a magnitude of a forward power flow, and the data acquisition unit acquires forward power flow data indicating the forward power flow of the first phase, the forward power flow of the second phase, and the forward power flow of the third phase. As the tidal current data Get Satisfy the first condition The first line voltage data, the second line voltage data, the third line voltage data, and the transformer voltage data indicating the line voltages in the case The connection phase estimation unit estimates a connection phase based on the forward power flow data acquired as the power flow data. You may do so.

[0011] In the above-described connection phase estimation device, the power flow data includes reverse power flow data indicating a magnitude of a reverse power flow, and the data acquisition unit acquires data of the first phase, the second phase, and The reverse power flow data indicating the reverse power flow to the third phase As the tidal current data Get The second condition is satisfied The first line voltage data, the second line voltage data, the third line voltage data, and the transformer voltage data indicating the line voltages in the case The connection phase estimation unit estimates a connection phase based on the reverse power flow data acquired as the power flow data. You may do so.

[0012] In the above-described connected phase estimation device, the data acquisition unit detects whether a total of loads connected to the first phase, the second phase, or the third phase is equal to or smaller than a predetermined threshold value. The first additional condition is also met. The first line voltage data, the second line voltage data, the third line voltage data, and transformer voltage data may be obtained, which indicate line voltages in a case where the first line voltage data, the second line voltage data, the third line voltage data, and transformer voltage data are obtained.

[0013] In addition, in the above-mentioned connection phase estimation device, the data acquisition unit may further acquire total load data indicating a sum of loads connected to the first phase, the second phase, or the third phase and managed by high-voltage consumers, and acquire the first line-to-line voltage data, the second line-to-line voltage data, the third line-to-line voltage data, and transformer voltage data when a third condition is satisfied in which the sum of the loads indicated by the total load data is equal to or greater than a predetermined threshold value.

[0015] Moreover, in the above-described connection phase estimation device, the data acquisition unit may further acquire instruction data indicating content of an instruction to acquire the first line-to-line voltage data, the second line-to-line voltage data, the third line-to-line voltage data, and transformer voltage data, and when acquiring the instruction data, acquire the first line-to-line voltage data, the second line-to-line voltage data, the third line-to-line voltage data, and transformer voltage data.

[0016] In addition, in the above-described connection phase estimation device, the data acquisition unit may acquire the first line-to-line voltage data, the second line-to-line voltage data, the third line-to-line voltage data, and transformer voltage data indicating line voltages at preset timing.

[0017] In addition, in the above-mentioned connection phase estimation device, the data acquisition unit may further acquire interconnected equipment data indicating at least one of a fact that equipment connected to the first phase, the second phase or the third phase has been updated, a fact that new equipment has been connected to the first phase, the second phase or the third phase, and a fact that equipment connected to the first phase, the second phase or the third phase has been removed, and when acquiring the interconnected equipment data, may acquire the first line-to-line voltage data, the second line-to-line voltage data, the third line-to-line voltage data and transformer voltage data.

[0018] In the above-described connection phase estimation device, the connection phase estimation unit calculates a first correlation coefficient between the line voltage indicated by the first line voltage data and the line voltage indicated by the transformer voltage data, a second correlation coefficient between the line voltage indicated by the second line voltage data and the line voltage indicated by the transformer voltage data, and a third correlation coefficient between the line voltage indicated by the third line voltage data and the line voltage indicated by the transformer voltage data. each It may be possible to calculate a correlation coefficient that is the largest among the first correlation coefficient, the second correlation coefficient, and the third correlation coefficient, and estimate that the single-phase transformer is connected to a phase that gives the largest correlation coefficient among the first correlation coefficient, the second correlation coefficient, and the third correlation coefficient.

[0020] According to one aspect of the present invention, a computer is provided that displays a first phase power flow, a second phase power flow, and a third phase power flow for a first phase, a second phase, and a third phase of a three-phase AC current outputted from a substation. data indicating a magnitude of forward power flow from the first phase, the second phase, and the third phase, or a magnitude of reverse power flow to the first phase, the second phase, and the third phase; Tidal current data, When the forward power flow shown in FIG. 1 is equal to or less than a predetermined threshold, a first condition is satisfied, or when the reverse power flow is equal to or less than a predetermined threshold, a second condition is satisfied. in the case where the transformer is a single-phase transformer, first line voltage data indicating a line voltage between a first phase and a second phase, second line voltage data indicating a line voltage between a second phase and a third phase of a three-phase AC output from the transformer, and third line voltage data indicating a line voltage between a third phase and a first phase of the three-phase AC output from the transformer, and and a connection phase estimation function of estimating a connection phase to which the single-phase transformer is connected, among a first phase, a second phase, and a third phase of a three-phase AC output from the substation, based on at least one of a correlation between the line voltage indicated by the first line voltage data and the line voltage indicated by the transformer voltage data, a correlation between the line voltage indicated by the second line voltage data and the line voltage indicated by the transformer voltage data, and a correlation between the line voltage indicated by the third line voltage data and the line voltage indicated by the transformer voltage data.

[0021] In one aspect of the present invention, the data acquisition unit or the data acquisition function is configured to display a first-phase current flow, a second-phase current flow, and a third-phase current flow for a first phase, a second phase, and a third phase of a three-phase AC current outputted from a substation. data, the power flow data indicating a magnitude of a forward power flow from the first phase, the second phase, and the third phase, or a magnitude of a reverse power flow to the first phase, the second phase, and the third phase, and a first condition that the forward power flow indicated by the power flow data is equal to or smaller than a predetermined threshold is satisfied, or a second condition that the reverse power flow is equal to or smaller than a predetermined threshold is satisfied.in the case where, first line voltage data indicating a line voltage between a first phase and a second phase, second line voltage data indicating a line voltage between a second phase and a third phase of a three-phase AC outputted by the substation, and third line voltage data indicating a line voltage between a third phase and a first phase of the three-phase AC outputted by the substation and and transformer voltage data indicating a line-to-line voltage of a single-phase transformer, and a connection phase estimation unit or connection phase estimation function estimates a connection phase to which the single-phase transformer is connected, among a first phase, a second phase, and a third phase of a three-phase AC output by the substation, based on at least one of a correlation between the line-to-line voltage indicated by the first line voltage data and the line voltage indicated by the transformer voltage data, a correlation between the line-to-line voltage indicated by the second line voltage data and the line voltage indicated by the transformer voltage data, and a correlation between the line-to-line voltage indicated by the third line voltage data and the line voltage indicated by the transformer voltage data. Effect of the Invention

[0022] According to the present invention, the connection phase of a transformer can be estimated with higher accuracy. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a diagram illustrating an example of a power distribution network according to an embodiment. [Diagram 2] FIG. 2 is a diagram illustrating an example of a functional configuration of a connection phase estimation device according to an embodiment. [Diagram 3] FIG. 11 is a diagram for explaining an example of a first condition imposed on first line voltage data, second line voltage data, third line voltage data, and substation voltage data acquired by the connection phase estimation device according to the embodiment. [Figure 4] FIG. 13 is a diagram for explaining an example of a second condition imposed on the first line voltage data, the second line voltage data, the third line voltage data, and the substation voltage data acquired by the connection phase estimation device according to the embodiment. [Diagram 5] FIG. 13 is a diagram for explaining an example of a third condition imposed on the first line voltage data, the second line voltage data, the third line voltage data, and the substation voltage data acquired by the connection phase estimation device according to the embodiment. [Figure 6] FIG. 11 is a diagram showing an example of a correlation between each of the line voltages between the first phase and the second phase, the line voltage between the second phase and the third phase, and the line voltage between the third phase and the first phase of a power distribution network according to an embodiment, and the line voltage of a single-phase transformer. [Figure 7] 4 is a flowchart illustrating an example of a process executed by a connected phase estimation device according to the embodiment. [Figure 8] FIG. 12 is a diagram showing locations where the thirteen single-phase transformers shown in FIGS. 9 to 11 are connected in a power distribution network according to an embodiment. [Figure 9] FIG. 13 is a diagram showing an example of the results of estimating a distribution line to which a single-phase transformer is connected, without taking into consideration the relationship between the power flow indicated by the power flow data and a predetermined threshold, the relationship between the reverse power flow indicated by the reverse power flow data and a predetermined threshold, and the relationship between the total load managed by high-voltage consumers and the predetermined threshold. [Figure 10] FIG. 11 is a diagram showing an example of a result of estimating a power distribution line to which a single-phase transformer is connected, taking into consideration only the magnitude relationship between the power flow indicated by the power flow data and a predetermined threshold value. [Figure 11] FIG. 13 is a diagram showing an example of the results of estimating a distribution line to which a single-phase transformer is connected, taking into account the relationship between the power flow indicated by the power flow data and a predetermined threshold, the relationship between the reverse power flow indicated by the reverse power flow data and a predetermined threshold, and the relationship between the total load managed by high-voltage consumers and the predetermined threshold. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] An example of a connection phase estimation device according to an embodiment will be described with reference to FIGS. 1 to 6. FIG.

[0025] First, an example of a power distribution network to which a connection phase estimation device according to an embodiment is applied will be described with reference to Fig. 1. Fig. 1 is a diagram showing an example of a power distribution network according to an embodiment. As shown in Fig. 1, the power distribution network 1 includes a substation 2, a power distribution line 3, single-phase transformers 41, ..., single-phase transformer 4k, a low-voltage consumer group 5, a high-voltage consumer group 6, a power generation company group 7, and a switch 8.

[0026] The substation 2 is a facility that converts the voltage of three-phase AC transmitted from a power plant via a transmission line into a predetermined voltage, for example, 6600 V, and supplies the three-phase AC to a distribution line 3.

[0027] The distribution line 3 includes a first distribution line 31, a second distribution line 32, and a third distribution line 33. The first distribution line 31, the second distribution line 32, and the third distribution line 33 are, for example, overhead distribution lines strung on utility poles, or underground distribution lines buried underground. The first distribution line 31 carries a first phase current of the three-phase AC current flowed by the substation 2. Similarly, the second distribution line 32 carries a second phase current of the three-phase AC current flowed by the substation 2. The third distribution line 33 carries a third phase current of the three-phase AC current flowed by the substation 2. The first phase, the second phase, and the third phase are the U phase, the V phase, and the W phase of the distribution line 3, respectively.

[0028] The single-phase transformers 41, ..., and 4k (k: a natural number equal to or greater than 2) are pole-mounted transformers that convert, for example, three-phase power of 6600 V into single-phase power of 200 V or single-phase power of 100 V. In addition, the single-phase transformers 41, ..., and 4k are connected to two of the first, second, and third phases of the three-phase AC output from the substation 2.

[0029] The low-voltage consumer group 5 includes low-voltage consumers 51, ..., and low-voltage consumers 5k. The low-voltage consumer 51 has equipment connected to the single-phase transformer 41, and is a consumer that uses power obtained by converting 6600V three-phase power into 200V single-phase power or 100V single-phase power by a pole transformer. Similarly, the low-voltage consumers 52, ..., and low-voltage consumers 5k have equipment connected to the single-phase transformers 42, ..., and single-phase transformer 4k, respectively, and are consumers that use power obtained by converting 6600V three-phase power into 200V single-phase power or 100V single-phase power by a pole transformer. The low-voltage consumers 51, ..., and low-voltage consumers 5k may be, for example, ordinary households.

[0030] 1, the low-voltage consumer 51 includes a smart meter 511 and a distributed power source 521. Similarly, the low-voltage consumer 52, ..., low-voltage consumer 5k include smart meters 512, ..., smart meter 51k and distributed power sources 522, ..., distributed power sources 52k, respectively.

[0031] The smart meter 511 has a communication function, and for example, measures the line voltage on the secondary side of the single-phase transformer 41 that supplies power to the low-voltage consumer 51, and generates transformer voltage data indicating the line voltage. The smart meter 511 then stores the transformer voltage data in a storage device provided inside or outside the smart meter 51k. Also, for example, the smart meter 51k has a communication function, and measures the line voltage on the secondary side of the single-phase transformer 4k that supplies power to the low-voltage consumer 5k, and generates transformer voltage data indicating the line voltage. The smart meter 51k then stores the transformer voltage data in a storage device provided inside or outside the smart meter 51k. Also, for example, the line voltages indicated by these transformer voltage data are all averages of the line voltages in a predetermined period. Also, the predetermined period referred to here is, for example, 1 minute, 10 minutes, or 30 minutes.

[0032] The distributed power sources 521, ..., 52k are, for example, distributed power sources such as solar panels, and supply the power generated by themselves back to two of the first distribution line 31, the second distribution line 32, and the third distribution line 33. Note that at least one of the low voltage consumers 51, ..., 5k does not necessarily have the distributed power sources 521, ..., 52k.

[0033] The high voltage consumer group 6 includes high voltage consumers 61, ..., 6m (m: natural number of 2 or more). The high voltage consumers 61, ..., 6m have equipment connected to the first distribution line 31, the second distribution line 32, and the third distribution line 33, and are consumers that convert three-phase power received at 6600V to a desired voltage for use. Examples of the high voltage consumers 61, ..., 6m include factories and large apartment buildings. Examples of equipment that each of the high voltage consumers 61, ..., 6m operates using three-phase power include motors.

[0034] The power generation business group 7 includes power generation business operators 71, ..., and 7n (n: a natural number equal to or greater than 2). The power generation business operators 71, ..., and 7n generate electricity using renewable energy and transmit it back to the power distribution line 3. Examples of renewable energy include solar power, wind power, geothermal power, hydroelectric power, and biomass.

[0035] The switch 8 is a switch that switches between a case where three-phase AC is passed through the first distribution line 31, the second distribution line 32, and the third distribution line 33, and a case where three-phase AC is not passed through the first distribution line 31, the second distribution line 32, and the third distribution line 33.

[0036] The switch 8 also includes a voltmeter that measures the line voltage between the first and second phases, the line voltage between the second and third phases, and the line voltage between the third and first phases of the three-phase AC current passed by the substation 2. For example, the voltmeter measures the line voltage between the first and second phases, and generates first line voltage data indicating the line voltage. The voltmeter also measures the line voltage between the second and third phases, and generates second line voltage data indicating the line voltage. The voltmeter also measures the line voltage between the third and first phases, and generates third line voltage data indicating the line voltage. The first line voltage data, second line voltage data, and third line voltage data are stored in a storage device provided inside or outside the switch 8, for example.

[0037] Moreover, the line voltage indicated by the first line voltage data, the line voltage indicated by the second line voltage data, and the line voltage indicated by the third line voltage data are all averages of the line voltages in a predetermined period. The predetermined period is 10 minutes or 30 minutes. Furthermore, it is preferable that this predetermined period has the same length as the predetermined period related to the transformer voltage data described above, and that the start and end of the predetermined period coincide with the start and end of the predetermined period related to the transformer voltage data described above.

[0038] The switchgear 8 also includes a current transformer (CT) and a voltage transformer (VT). The current transformer is a device used to expand the range of current that can be measured by the ammeter included in the switchgear 8. The voltage transformer is a device that steps down a high voltage to a voltage that can be used by the above-mentioned voltmeter and the like. The current transformer and voltage transformer are attached to a position of the switchgear 8 on the substation 2 side.

[0039] Next, a connection phase estimation device according to an embodiment will be described with reference to Fig. 2 to Fig. 6. Fig. 2 is a diagram showing an example of a functional configuration of a connection phase estimation device according to an embodiment. As shown in Fig. 2, a connection phase estimation device 9 includes a data acquisition unit 91 and a connection phase estimation unit 92.

[0040] The data acquiring unit 91 acquires the first line voltage data, the second line voltage data, and the third line voltage data from the above-mentioned storage device. The data acquiring unit 91 acquires the substation voltage data from the above-mentioned storage device. Furthermore, at least one of a first condition, a second condition, and a third condition described below may be imposed on the first line voltage data, the second line voltage data, the third line voltage data, and the substation voltage data acquired by the data acquiring unit 91.

[0041] Fig. 3 is a diagram for explaining an example of a first condition imposed on the first line voltage data, the second line voltage data, the third line voltage data, and the substation voltage data acquired by the connection phase estimation device according to the embodiment. The horizontal axis of Fig. 3 represents a distance along the distribution line 3 based on the position where the substation 2 is built. The vertical axis of Fig. 3 represents the line voltage between two of the first phase, the second phase, and the third phase of the three-phase AC output by the substation 2, and represents the line voltage converted into the voltage of the three-phase AC supplied to the high-voltage consumer group 6.

[0042] FIG. 3 shows regions R, R1, and R2. Region R indicates the range in which the line voltage fluctuates when the power flow through the distribution line 3 is equal to or less than a predetermined threshold, regardless of whether the power flow through the distribution line 3 is a normal flow or a reverse flow. Region R1 indicates the range in which the line voltage fluctuates when the forward power flow through the distribution line 3 exceeds a predetermined threshold. Region R2 indicates the range in which the line voltage fluctuates when the reverse power flow through the distribution line 3 exceeds a predetermined threshold. The predetermined threshold is preferably about 1 / 3 of the maximum absolute value of the power flow measured during a predetermined period by an ammeter included in the switch 8, and may be about 1 / 3 of the maximum absolute value of the power flow that the distribution line 3 can design to flow upstream.

[0043] 3 also shows dashed lines SW and SM. The dashed line SW indicates the distance from the location where the reference substation 2 is located to the location where the line voltage is measured by a voltmeter included in the switch 8. The dashed line SM indicates the distance from the location where the reference substation 2 is located to the location where the line voltage is measured by the smart meter 511, ... or the smart meter 51k.

[0044] The first condition is that the first-phase current, the second-phase current, and the third-phase current of the three-phase AC output from the substation 2 are equal to or less than the above-mentioned predetermined threshold value.

[0045] When the first condition is not satisfied and the power flowing through the distribution line 3 is a smooth flow, even if the fluctuation in the line voltage measured by the voltmeter included in the switch 8 is small, the fluctuation in the line voltage measured by the smart meter 511, ... or the smart meter 51k becomes large, as shown by the region R1, the dashed line SW, and the dashed line SM in Fig. 3. Also, when the first condition is not satisfied and the power flowing through the distribution line 3 is an anti-harmonic flow, even if the fluctuation in the line voltage measured by the voltmeter included in the switch 8 is small, the fluctuation in the line voltage measured by the smart meter 511, ... or the smart meter 51k becomes large, as shown by the region R2, the dashed line SW, and the dashed line SM in Fig. 3. On the other hand, when the first condition is satisfied and the fluctuation in the line voltage measured by the voltmeter included in the switch 8 is small, the fluctuation in the line voltage measured by the smart meter 511, ... or the smart meter 51k becomes small, as shown by the region R, the dashed line SW, and the dashed line SM in Fig. 3.

[0046] Therefore, the correlation between the line voltage indicated by the first line voltage data and the line voltage indicated by the transformer voltage data is clearer when the first condition is satisfied than when the first condition is not satisfied. Similarly, the correlation between the line voltage indicated by the second line voltage data and the line voltage indicated by the transformer voltage data is clearer when the first condition is satisfied than when the first condition is not satisfied. Also, the correlation between the line voltage indicated by the third line voltage data and the line voltage indicated by the transformer voltage data is clearer when the first condition is satisfied than when the first condition is not satisfied.

[0047] When the first condition is taken into consideration, the data acquiring unit 91 acquires power flow data indicating a first-phase power flow, a second-phase power flow, and a third-phase power flow of the three-phase AC output by the substation 2. The power flow data is included in the switch 8, and is generated by an instrument current transformer that measures the first-phase power flow, the second-phase power flow, and the third-phase power flow of the three-phase AC output by the substation 2. Then, the data acquiring unit 91 acquires first line voltage data, second line voltage data, third line voltage data, and substation voltage data that indicate line voltages when the power flow indicated by the power flow data is equal to or less than the above-mentioned predetermined threshold value.

[0048] Fig. 4 is a diagram for explaining an example of a second condition imposed on the first line voltage data, the second line voltage data, the third line voltage data, and the substation voltage data acquired by the connection phase estimation device according to the embodiment. The horizontal axis of Fig. 4 represents a distance along the distribution line 3 based on the position where the substation 2 is built. The vertical axis of Fig. 4 represents the line voltage between two of the first phase, the second phase, and the third phase of the three-phase AC output by the substation 2, and represents the line voltage converted into the voltage of the three-phase AC supplied to the high-voltage consumer group 6.

[0049] Fig. 4 shows lines D and N. Line D shows the distribution of line voltage during the day. Line N shows the distribution of line voltage during the night. Fig. 4 also shows dashed lines SW and SM. Dashed line SW shows the distance from the location of reference substation 2 to the location where line voltage is measured by a voltmeter included in switch 8. Dashed line SM shows the distance from the location of reference substation 2 to the location where line voltage is measured by smart meter 511, ... or smart meter 51k.

[0050] 4 illustrates an example in which the distribution of line voltages is linear both during the day and at night, but is not limited to this. For example, at least one of the distribution of line voltages during the day and the distribution of line voltages during the night may show a curved distribution or a more complicated distribution.

[0051] The second condition is that the reverse power flow to the first phase, the second phase, or the third phase of the three-phase AC output from the substation 2 is equal to or less than a predetermined threshold value.

[0052] 4, the line voltage measured by the smart meter 511, ... or the smart meter 51k has a stronger correlation with the line voltage measured by the voltmeter included in the switch 8 at night than during the day. The reason for this is that during the day, the reverse power flow from the distributed power sources 521, ..., the distributed power sources 52k, etc. is relatively large, so that the reverse power flow has a large effect on the correlation, whereas at night, the reverse power flow from the distributed power sources 521, ..., the distributed power sources 52k, etc. is relatively small, so that the reverse power flow has a small effect on the correlation.

[0053] Therefore, the correlation between the line voltage indicated by the first line voltage data and the line voltage indicated by the transformer voltage data is clearer when the second condition is satisfied than when the second condition is not satisfied. Similarly, the correlation between the line voltage indicated by the second line voltage data and the line voltage indicated by the transformer voltage data is clearer when the second condition is satisfied than when the second condition is not satisfied. Furthermore, the correlation between the line voltage indicated by the third line voltage data and the line voltage indicated by the transformer voltage data is clearer when the second condition is satisfied than when the second condition is not satisfied.

[0054] When the second condition is taken into consideration, the data acquisition unit 91 acquires reverse power flow data indicating a reverse power flow to the first phase, the second phase, or the third phase of the three-phase AC output by the substation 2. The reverse power flow data is included in the switch 8 and is generated by an instrument current transformer that measures the first phase power flow, the second phase power flow, and the third phase power flow. The reverse power flow data indicates a power flow when the power flow measured by the instrument current transformer flows toward the substation. The data acquisition unit 91 then acquires first line voltage data, second line voltage data, third line voltage data, and substation voltage data indicating line voltages when the reverse power flow indicated by the reverse power flow data is equal to or less than the above-mentioned predetermined threshold value.

[0055] Furthermore, when considering at least one of the first condition and the second condition, the data acquisition unit 91 may acquire first line voltage data, second line voltage data, third line voltage data, and substation voltage data that further satisfy a first additional condition that the sum of the loads connected to the first phase, second phase, or third phase of the three-phase AC output from the substation 2 is equal to or less than a predetermined threshold. The loads referred to here include not only loads managed by the high-voltage consumers 61, ... or the high-voltage consumers 6m, but also loads managed by the low-voltage consumers 51, ... or the low-voltage consumers 5k, loads managed by the power generation companies 71, ..., or the power generation companies 7n, and the like.

[0056] The first additional condition is a condition that makes it easier for at least one of the first condition and the second condition to be satisfied. Examples of situations in which the first additional condition is satisfied include a situation in which the total load is small because the season is spring, autumn, or the like, and a situation in which the current measured by the instrument current transformer included in the switch 8 is equal to or smaller than a predetermined threshold. The predetermined threshold for the second additional condition may be the same as the predetermined threshold for the above-mentioned first additional condition, or may be a threshold different from the predetermined threshold.

[0057] Fig. 5 is a diagram for explaining an example of a third condition imposed on the first line voltage data, the second line voltage data, the third line voltage data, and the substation voltage data acquired by the connection phase estimation device according to the embodiment. The horizontal axis of Fig. 5 represents a distance along the distribution line 3 based on the position where the substation 2 is built. The vertical axis of Fig. 5 represents the line voltage between two of the first phase, the second phase, and the third phase of the three-phase AC output by the substation 2, and represents the line voltage converted into the voltage of the three-phase AC supplied to the high-voltage consumer group 6.

[0058] 5 shows lines L, L1, and L2. Line L is supplied with three-phase power from the distribution line 3, and shows the line voltage when the sum of the loads managed by each of the high-voltage consumers 61, ..., and 6m is a predetermined load. Lines L1 and L2 are supplied with three-phase power from the distribution line 3, and show the line voltage when the sum of the loads managed by each of the high-voltage consumers 61, ..., and 6m is changed from the predetermined load for line L.

[0059] 5 also shows dashed lines SW and SM. The dashed line SW indicates the distance from the location where the reference substation 2 is located to the location where the line voltage is measured by a voltmeter included in the switch 8. The dashed line SM indicates the distance from the location where the reference substation 2 is located to the location where the line voltage is measured by the smart meter 511, ... or the smart meter 51k.

[0060] When the line voltage at the position indicated by dashed line SW in Fig. 5 changes as shown by the solid arrow on the left, the impedance of the entire distribution line 3 is constant, so the line voltage at the position indicated by dashed line SM in Fig. 5 changes as shown by the solid arrow on the right, with the impedance as a proportional constant. Similarly, when the line voltage at the position indicated by dashed line SW in Fig. 5 changes as shown by the dashed arrow on the left, the impedance of the entire distribution line 3 is constant, so the line voltage at the position indicated by dashed line SM in Fig. 5 changes as shown by the dashed arrow on the right, with the impedance as a proportional constant.

[0061] The proportional relationship between the line voltage at the position indicated by the dashed line SW and the line voltage at the position indicated by the dashed line SM is established when the total load managed by each of the high-voltage consumers 61, ..., and 6m, which are connected to the first, second, or third phase of the three-phase AC output from the substation 2, is equal to or greater than a predetermined threshold. However, this proportional relationship is often an approximate proportional relationship defined by a certain degree of correlation rather than a strict proportional relationship. In addition, the reason why this proportional relationship is not a strict proportional relationship may be, for example, the influence of at least one load current of the low-voltage consumers 51, ..., the low-voltage consumers 5k, the high-voltage consumers 61, ..., the high-voltage consumers 6m, the power generation companies 71, ..., and the power generation companies 7n.

[0062] The third condition is that the substation 2 is connected to the first, second, or third phase of the three-phase AC output, and the sum of the loads managed by each of the high-voltage consumers 61, ..., 6m is greater than or equal to a predetermined threshold value.

[0063] The correlation between the line voltage indicated by the first line voltage data and the line voltage indicated by the transformer voltage data is clearer when the third condition is satisfied than when the third condition is not satisfied. Similarly, the correlation between the line voltage indicated by the second line voltage data and the line voltage indicated by the transformer voltage data is clearer when the third condition is satisfied than when the third condition is not satisfied. Also, the correlation between the line voltage indicated by the third line voltage data and the line voltage indicated by the transformer voltage data is clearer when the third condition is satisfied than when the third condition is not satisfied.

[0064] When the third condition is taken into consideration, the data acquisition unit 91 acquires total load data indicating the sum of the loads managed by each of the high-voltage consumers 61, ..., 6m, which are connected to the first phase, second phase, or third phase of the three-phase AC output by the substation 2. The total load data is generated by measuring the amount of power used by each of the high-voltage consumers 61, ..., 6m using a trading meter to calculate the sum of these amounts of power. Then, the data acquisition unit 91 acquires first line voltage data, second line voltage data, third line voltage data, and transformer voltage data when the sum of the loads indicated by the total load data is equal to or greater than a predetermined threshold value.

[0065] Furthermore, when considering at least one of the first condition and the second condition, the data acquisition unit 91 may acquire the first line voltage data, the second line voltage data, the third line voltage data, and the substation voltage data that further satisfy a second additional condition that the total of the loads connected to the first phase, the second phase, or the third phase of the three-phase AC output from the substation 2 is equal to or greater than a predetermined threshold. The loads referred to here include not only the loads managed by the high-voltage consumers 61, ..., or the high-voltage consumers 6m, but also the loads managed by the low-voltage consumers 51, ..., or the low-voltage consumers 5k, the loads managed by the power generation companies 71, ..., or the power generation companies 7n, and the like. The second additional condition is a condition that makes the above-mentioned third condition more likely to be satisfied. Examples of situations in which the third additional condition is satisfied include a situation in which the total of the loads is large due to the season being summer, winter, etc., and a situation in which the current measured by the instrument current transformer included in the switch 8 is equal to or less than a predetermined threshold.

[0066] Furthermore, the data acquiring unit 91 may acquire the first line voltage data, the second line voltage data, the third line voltage data, and the transformer voltage data when acquiring instruction data indicating content instructing the data acquiring unit 91 to acquire these data. The instruction data is generated, for example, when a button for causing the data acquiring unit 91 to acquire these data is pressed, or when a graphical user interface (GUI) for causing the data acquiring unit 91 to acquire these data is operated.

[0067] The connection phase estimation unit 92 estimates a connection phase among the first phase, the second phase, and the third phase of the three-phase AC output from the substation 2 for at least one of the single-phase transformers 41, ..., 4k, based on the correlation between the line voltage measured by the voltmeter included in the switch 8 and the line voltage indicated by the transformer voltage data. The correlation referred to here is at least one of the correlation between the line voltage indicated by the first line voltage data and the line voltage indicated by the transformer voltage data, the correlation between the line voltage indicated by the second line voltage data and the line voltage indicated by the transformer voltage data, and the correlation between the line voltage indicated by the third line voltage data and the line voltage indicated by the transformer voltage data.

[0068] For example, the connection phase estimation unit 92 calculates at least one of a first correlation coefficient, a second correlation coefficient, and a third correlation coefficient for the single-phase transformer 41. The first correlation coefficient is a correlation coefficient between the line voltage indicated by the first line voltage data and the line voltage indicated by the transformer voltage data. The second correlation coefficient is a correlation coefficient between the line voltage indicated by the second line voltage data and the line voltage indicated by the transformer voltage data. The third correlation coefficient is a correlation coefficient between the line voltage indicated by the third line voltage data and the line voltage indicated by the transformer voltage data. Note that, although the single-phase transformer 41 is described here as an example, the same applies to the single-phase transformer 42, ..., single-phase transformer 4k.

[0069] 6 is a diagram showing an example of a correlation between the line voltage between the first phase and the second phase, the line voltage between the second phase and the third phase, and the line voltage between the third phase and the first phase of the power distribution network according to the embodiment, and the line voltage of a single-phase transformer. UV and the line voltage V of the single-phase transformer 41. LOW FIG. 6(a) shows an example in which the correlation coefficient between the line voltage V between the second phase and the third phase is relatively small. VW and the line voltage V of the single-phase transformer 41. LOW FIG. 6(b) shows an example in which the correlation coefficient between the line voltage V between the third phase and the first phase is relatively large. WU and the line voltage V of the single-phase transformer 41. LOW FIG. 6(c) shows an example in which the correlation coefficient between is relatively small.

[0070] The connected phase estimation unit 92 estimates that the single-phase transformer 41 is connected to the phase that gives the maximum correlation coefficient among the first correlation coefficient, the second correlation coefficient, and the third correlation coefficient. For example, when the first correlation coefficient, the second correlation coefficient, and the third correlation coefficient that give the correlation shown in Fig. 6 have been calculated, the connected phase estimation unit 92 estimates that the single-phase transformer 41 is connected to the second phase and the third phase.

[0071] Next, an example of a process executed by the connection phase estimation device according to the embodiment will be described with reference to Fig. 7. Fig. 7 is a flowchart showing an example of a process executed by the connection phase estimation device according to the embodiment. Note that, in the description of Fig. 7, the single-phase transformer 41 will be taken as an example, but the same applies to the single-phase transformer 42, ..., single-phase transformer 4k.

[0072] In step S10, the data acquisition unit 91 acquires first line voltage data, second line voltage data, third line voltage data, and transformer voltage data.

[0073] In step S20, the connection phase estimation unit 92 estimates the connection phase to which the single-phase transformer 41 is connected, among the first phase, the second phase, and the third phase of the three-phase AC output from the substation 2.

[0074] The connection phase estimation device 9 according to the embodiment has been described above. The connection phase estimation device 9 estimates the distribution line to which the single-phase transformer 41 or the like is connected among the first, second, and third phases of the three-phase AC output from the substation 2, based on the correlation between each of the line voltages between the first phase and the second phase, the line voltage between the second phase and the third phase, and the line voltage between the third phase and the first phase and the line voltage of the single-phase transformer 41 or the like. As a result, the connection phase estimation device 9 can more accurately estimate the connection phase of the single-phase transformer 41 or the like based on the correlation between the line voltage measured by the voltmeter included in the switch 8 and the line voltage measured by the smart meter 511, which are physical quantities that are highly correlated with each other.

[0075] Furthermore, the connection phase estimation device 9 acquires the first line voltage data, the second line voltage data, the third line voltage data, and the transformer voltage data that satisfy the first condition described above. These data indicate the line voltages when the fluctuations of the line voltages of the single-phase transformer 41, etc. measured by the smart meter 511 are small because the power flow through the power distribution line 3 is equal to or less than a predetermined threshold. Therefore, the connection phase estimation device 9 can estimate the connection phases of the single-phase transformer 41, etc. with higher accuracy based on the correlation when the correlation between the line voltages measured by the voltmeter included in the switch 8 and the line voltages of the single-phase transformer 41, etc. measured by the smart meter 511 becomes strong.

[0076] Furthermore, the connection phase estimation device 9 acquires the first line voltage data, the second line voltage data, the third line voltage data, and the transformer voltage data that satisfy the above-mentioned second condition. These data indicate the line voltages in the case where the fluctuation of the line voltages of the single-phase transformer 41, etc. measured by the smart meter 511 is small because the reverse power flow to the power distribution line 3 is equal to or less than a predetermined threshold. Therefore, the connection phase estimation device 9 can estimate the connection phases of the single-phase transformer 41, etc. with higher accuracy based on the correlation in the case where the correlation between the line voltages measured by the voltmeter included in the switch 8 and the line voltages of the single-phase transformer 41, etc. measured by the smart meter 511 is strong.

[0077] Furthermore, the connection phase estimation device 9 acquires the first line voltage data, the second line voltage data, the third line voltage data, and the transformer voltage data that not only satisfy at least one of the above-mentioned first condition and second condition, but also satisfy the above-mentioned first additional condition. This allows the connection phase estimation device 9 to more reliably execute the process of estimating the connection phase of the single-phase transformer 41, etc., based on the correlation when the correlation between the line voltage measured by the voltmeter included in the switch 8 and the line voltage of the single-phase transformer 41, etc., measured by the smart meter 511 is strong.

[0078] Furthermore, the connection phase estimation device 9 acquires the first line voltage data, the second line voltage data, the third line voltage data, and the transformer voltage data that satisfy the third condition described above. These data indicate the line voltages when the correlation between the line voltages measured by the voltmeter included in the switch 8 and the line voltages of the single-phase transformer 41, etc. measured by the smart meter 511 is strong because the total of the loads managed by each of the high-voltage consumers 61, ..., 6m is equal to or greater than a predetermined threshold. Therefore, the connection phase estimation device 9 can more accurately estimate the connection phases of the single-phase transformer 41, etc. based on the correlation when the correlation between the two is strong.

[0079] Furthermore, the connection phase estimation device 9 acquires the first line voltage data, the second line voltage data, the third line voltage data, and the transformer voltage data that not only satisfy the third condition described above, but also satisfy the second additional condition described above. This allows the connection phase estimation device 9 to more reliably execute the process of estimating the connection phase of the single-phase transformer 41, etc., based on the correlation when the correlation between the line voltage measured by the voltmeter included in the switch 8 and the line voltage of the single-phase transformer 41, etc., measured by the smart meter 511 is strong.

[0080] Furthermore, when the connection phase estimation device 9 receives instruction data indicating an instruction to acquire the first line voltage data, the second line voltage data, the third line voltage data, and the transformer voltage data, the connection phase estimation device 9 acquires the first line voltage data, the second line voltage data, the third line voltage data, and the transformer voltage data, thereby enabling the connection phase estimation device 9 to acquire these data at a timing desired by the user.

[0081] Next, a specific example of the effect of the connection phase estimation device 9 will be described with reference to Fig. 8 to Fig. 11. Fig. 8 is a diagram showing locations where thirteen single-phase transformers shown in Figs. 9 to 11 are connected in a power distribution network according to an embodiment. The first to thirteenth single-phase transformers shown in Figs. 9 to 11 are installed at positions indicated by circled numbers in Fig. 8. Moreover, switches 801 and 802 shown in Fig. 8 are switches installed at the boundary between the distribution line 3 and another adjacent distribution line, and are normally in a state where no electricity flows.

[0082] Fig. 9 is a diagram showing an example of the result of estimating the distribution line to which single-phase transformers are connected without considering the magnitude relationship between the power flow indicated by the power flow data and a predetermined threshold, the magnitude relationship between the reverse power flow indicated by the reverse power flow data and a predetermined threshold, and the magnitude relationship between the total load managed by high-voltage consumers and the predetermined threshold. In this case, as shown in Fig. 9, the estimation results of the connection phases for the third, fourth, eleventh, twelfth, and thirteenth single-phase transformers are different from the correct answer.

[0083] Fig. 10 is a diagram showing an example of the result of estimating the distribution line to which the single-phase transformers are connected, taking into consideration only the magnitude relationship between the power flow indicated by the power flow data and a predetermined threshold value. In this case, as shown in Fig. 10, the estimation result of the connection phase by the connection phase estimation device 9 is consistent with the correct connection phase, except for the third single-phase transformer.

[0084] Fig. 11 is a diagram showing an example of the result of estimating the distribution line to which the single-phase transformer is connected, taking into consideration the magnitude relationship between the power flow indicated by the power flow data and a predetermined threshold, the magnitude relationship between the reverse power flow indicated by the reverse power flow data and a predetermined threshold, and the magnitude relationship between the total load managed by the high-voltage consumers and the predetermined threshold. In this case, as shown in Fig. 11, the estimation result of the connection phase by the connection phase estimation device 9 matches the correct connection phase for all thirteen single-phase transformers.

[0085] In the above embodiment, the smart meters 511, ..., and 51k measure the line voltages on the secondary sides of the single-phase transformers 41, ..., and 4k, respectively. However, the present invention is not limited to this. The smart meters 511, ..., and 51k may measure the line voltages on the primary sides of the single-phase transformers 41, ..., and 4k, respectively.

[0086] In the above embodiment, the line voltage indicated by the transformer voltage data is the average line voltage in a predetermined period, but the present invention is not limited to this. For example, the line voltage indicated by the transformer voltage data may be a statistic other than the average line voltage in a predetermined period, or may be the instantaneous line voltage measured by the smart meter 511, ... or the smart meter 51k.

[0087] In the above embodiment, the line voltage indicated by the first line voltage data, the line voltage indicated by the second line voltage data, and the line voltage indicated by the third line voltage data are averages of line voltages in a predetermined period of time. However, this is not limiting. For example, these line voltages may be statistics other than the averages of line voltages in a predetermined period of time, or may be instantaneous line voltages measured by the smart meter 511, ..., or the smart meter 51k.

[0088] In addition, in the above-described embodiment, an example has been described in which the data acquisition unit 91 acquires first line-to-line voltage data, second line-to-line voltage data, third line-to-line voltage data, and transformer voltage data when it acquires instruction data, but this is not limited to this.

[0089] For example, the data acquiring unit 91 may acquire first line voltage data, second line voltage data, third line voltage data, and transformer voltage data indicating line voltages at preset timings, whereby the connection phase estimating device 9 can constantly collect these data and estimate the connection phases of the single-phase transformer 41, etc., as necessary.

[0090] Alternatively, when the data acquisition unit 91 acquires the interconnected equipment data, the data acquisition unit 91 may acquire the first line voltage data, the second line voltage data, the third line voltage data, and the transformer voltage data. The interconnected equipment data is data indicating at least one of the fact that the equipment connected to the first phase, the second phase, or the third phase of the three-phase AC output from the substation 2 has been updated, the fact that new equipment has been connected to the first phase, the second phase, or the third phase, and the fact that equipment connected to the first phase, the second phase, or the third phase has been removed. This allows the connection phase estimation device 9 to quickly estimate the connection phase of the single-phase transformer 41, etc., when the equipment connected to the distribution line 3 has been updated or the like.

[0091] In addition, a program for realizing each function of the data acquisition unit 91 and the connection phase estimation unit 92 according to the above-mentioned embodiment may be recorded in a computer-readable recording medium, and the program recorded in this recording medium may be read into a computer system and executed, thereby performing processing.

[0092] The computer system referred to here may include hardware such as an operating system (OS) or peripheral devices, etc. Also, computer-readable recording media include, for example, floppy disks, magneto-optical disks, ROMs (Read Only Memory), writable non-volatile memories such as flash memories, portable media such as DVDs (Digital Versatile Discs), storage devices such as hard disks built into computer systems, and volatile memories inside computer systems that are servers or clients when a program is transmitted via a network or communication line, which hold a program for a certain period of time.

[0093] The above-mentioned program may be transmitted from a computer system in which the program is stored in a storage device or the like to another computer system via a transmission medium or by transmission waves in the transmission medium. Here, the transmission medium for transmitting the program refers to a medium having a function for transmitting information, such as a network such as the Internet or a communication line such as a telephone line.

[0094] The above-mentioned program may be for implementing part of the above-mentioned functions, or may be a so-called differential program that can implement part of the above-mentioned functions in combination with a program already recorded in the computer system. The above-mentioned program is read and executed by a processor such as a CPU (Central Processing Unit) provided in the computer, for example.

[0095] Although the embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and various modifications, substitutions, and design changes can be made without departing from the scope of the present invention. In addition, the configurations described in the above-mentioned embodiment may be combined. [Explanation of symbols]

[0096] 1...power distribution network, 2...substation, 3...power distribution line, 31...first power distribution line, 32...second power distribution line, 33...third power distribution line, 41,...,4k...single-phase transformer, 5...low-voltage consumer group, 51,...,5k...low-voltage consumer, 511,...,51k...smart meter, 521,...,52k...distributed power source, 6...high-voltage consumer group, 61,...,6m...high-voltage consumer, 71,...,7n...power generation company, 8,801,802...switch, 9...connection phase estimation device, 91...data acquisition unit, 92...connection phase estimation unit

Claims

1. a data acquiring unit that acquires data indicating a first-phase power flow, a second-phase power flow, and a third-phase power flow for a first phase, a second phase, and a third phase of a three-phase AC output from a substation, the data acquiring unit acquiring power flow data indicating a magnitude of a forward power flow from the first phase, the second phase, and the third phase, or a magnitude of a reverse power flow to the first phase, the second phase, and the third phase, first line voltage data indicating a line voltage between a first phase and a second phase when a first condition that a forward power flow indicated by the power flow data is equal to or smaller than a predetermined threshold value is satisfied, or when a second condition that a reverse power flow is equal to or smaller than a predetermined threshold value is satisfied, second line voltage data indicating a line voltage between a second phase and a third phase of the three-phase AC output from the substation, third line voltage data indicating a line voltage between a third phase and a first phase of the three-phase AC output from the substation, and transformer voltage data indicating a line voltage of a single-phase transformer; a connection phase estimation unit that estimates a connection phase to which the single-phase transformer is connected, among a first phase, a second phase, and a third phase of a three-phase AC output from the substation, based on at least one of a correlation between the line voltage indicated by the first line voltage data and the line voltage indicated by the transformer voltage data, a correlation between the line voltage indicated by the second line voltage data and the line voltage indicated by the transformer voltage data, and a correlation between the line voltage indicated by the third line voltage data and the line voltage indicated by the transformer voltage data; A connection phase estimation device comprising:

2. The power flow data includes forward power flow data indicating a magnitude of a forward power flow, the data acquisition unit acquires, as the power flow data, forward power flow data indicating a forward power flow of the first phase, a forward power flow of the second phase, and a forward power flow of the third phase, and acquires the first line-to-line voltage data, the second line-to-line voltage data, the third line-to-line voltage data, and transformer voltage data indicating line voltages when the first condition is satisfied; the connection phase estimation unit estimates a connection phase based on the forward power flow data acquired as the power flow data. The connection phase estimation device according to claim 1 .

3. The power flow data includes reverse power flow data indicating a magnitude of reverse power flow, the data acquisition unit acquires, as the power flow data, reverse power flow data indicating reverse power flow to the first phase, the second phase, and the third phase, and acquires the first line-to-line voltage data, the second line-to-line voltage data, the third line-to-line voltage data, and transformer voltage data indicating line voltages in a case where the second condition is satisfied; the connection phase estimation unit estimates a connection phase based on the reverse power flow data acquired as the power flow data. The connection phase estimation device according to claim 1 .

4. the data acquisition unit acquires the first line voltage data, the second line voltage data, the third line voltage data, and transformer voltage data indicating line voltages when a first additional condition is further satisfied that a sum of loads connected to the first phase, the second phase, or the third phase is equal to or less than a predetermined threshold value; The connection phase estimation device according to claim 2 or 3.

5. the data acquisition unit further acquires total load data indicating a total of loads that are connected to the first phase, the second phase, or the third phase and are managed by high voltage consumers, and acquires the first line voltage data, the second line voltage data, the third line voltage data, and transformer voltage data when a third condition is satisfied in which the total load data indicates a total of loads that is equal to or greater than a predetermined threshold value; the connection phase estimation unit estimates a connection phase to which the single-phase transformer is connected, among a first phase, a second phase, and a third phase of a three-phase AC output from the substation, based on the correlation calculated from the first line voltage data, the second line voltage data, the third line voltage data, and the transformer voltage data acquired when the third condition is satisfied. The connection phase estimation device according to any one of claims 1 to 4.

6. the data acquisition unit further acquires instruction data indicating content instructing to acquire the first line voltage data, the second line voltage data, the third line voltage data, and transformer voltage data, and when acquiring the instruction data, acquires the first line voltage data, the second line voltage data, the third line voltage data, and the transformer voltage data. The connection phase estimation device according to any one of claims 1 to 5.

7. the data acquisition unit acquires the first line voltage data, the second line voltage data, the third line voltage data, and transformer voltage data, each of which indicates a line voltage at a preset timing; The connection phase estimation device according to any one of claims 1 to 5.

8. the data acquisition unit further acquires interconnected equipment data indicating at least one of a fact that equipment connected to the first phase, the second phase, or the third phase has been updated, a fact that new equipment has been connected to the first phase, the second phase, or the third phase, and a fact that equipment connected to the first phase, the second phase, or the third phase has been removed, and when acquiring the interconnected equipment data, acquires the first line voltage data, the second line voltage data, the third line voltage data, and transformer voltage data. The connection phase estimation device according to any one of claims 1 to 5.

9. the connected phase estimation unit calculates a first correlation coefficient between the line-to-line voltage indicated by the first line voltage data and the line-to-line voltage indicated by the transformer voltage data, a second correlation coefficient between the line-to-line voltage indicated by the second line voltage data and the line-to-line voltage indicated by the transformer voltage data, and a third correlation coefficient between the line-to-line voltage indicated by the third line voltage data and the line-to-line voltage indicated by the transformer voltage data, and estimates that the single-phase transformer is connected to a phase giving a maximum correlation coefficient among the first correlation coefficient, the second correlation coefficient, and the third correlation coefficient. The connection phase estimation device according to any one of claims 1 to 8.

10. On the computer, a data acquisition function for acquiring data indicating a first-phase power flow, a second-phase power flow, and a third-phase power flow for a first phase, a second phase, and a third phase of a three-phase AC output from a substation, the data including power flow data indicating a magnitude of a forward power flow from the first phase, the second phase, and the third phase, or a magnitude of a reverse power flow to the first phase, the second phase, and the third phase, first line voltage data indicating a line voltage between a first phase and a second phase when a first condition that a forward power flow indicated by the power flow data is equal to or less than a predetermined threshold value is satisfied, or when a second condition that a reverse power flow is equal to or less than a predetermined threshold value is satisfied, second line voltage data indicating a line voltage between a second phase and a third phase of the three-phase AC output from the substation, third line voltage data indicating a line voltage between a third phase and a first phase of the three-phase AC output from the substation, and transformer voltage data indicating a line voltage of a single-phase transformer; a connection phase estimation function that estimates a connection phase to which the single-phase transformer is connected, among a first phase, a second phase, and a third phase of a three-phase AC output from the substation, based on at least one of a correlation between the line voltage indicated by the first line voltage data and the line voltage indicated by the transformer voltage data, a correlation between the line voltage indicated by the second line voltage data and the line voltage indicated by the transformer voltage data, and a correlation between the line voltage indicated by the third line voltage data and the line voltage indicated by the transformer voltage data; A connection phase estimation program that executes the above.

11. a data acquisition unit or a data acquisition function acquires data indicating a first-phase power flow, a second-phase power flow, and a third-phase power flow for a first phase, a second phase, and a third phase of a three-phase AC output from a substation, the data acquiring unit or the data acquiring function acquiring the following data: power flow data indicating a magnitude of a forward power flow from the first phase, the second phase, and the third phase, or a magnitude of a reverse power flow to the first phase, the second phase, and the third phase; first line voltage data indicating a line voltage between a first phase and a second phase when a first condition that a forward power flow indicated by the power flow data is equal to or less than a predetermined threshold is satisfied, or when a second condition that a reverse power flow is equal to or less than a predetermined threshold is satisfied; second line voltage data indicating a line voltage between a second phase and a third phase of the three-phase AC output from the substation; and third line voltage data indicating a line voltage between a third phase and a first phase of the three-phase AC output from the substation; and transformer voltage data indicating a line voltage of a single-phase transformer; a connection phase estimation unit or a connection phase estimation function estimates a connection phase to which the single-phase transformer is connected among a first phase, a second phase, and a third phase of a three-phase AC output from the substation, based on at least one of a correlation between the line voltage indicated by the first line voltage data and the line voltage indicated by the transformer voltage data, a correlation between the line voltage indicated by the second line voltage data and the line voltage indicated by the transformer voltage data, and a correlation between the line voltage indicated by the third line voltage data and the line voltage indicated by the transformer voltage data. Connection phase estimation method.

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