JP5485421B1 - Connection phase determination method and connection phase determination device - Google Patents

Abstract

A connection phase of a pole transformer is determined so that the degree of unbalance of a three-phase AC voltage can be suppressed.
The primary of a plurality of pole transformers in which a primary side is connected to any two phases of three phases of a three-phase distribution line to which power is supplied from the upstream side, and a power load is connected to the secondary side. A connection phase determination method for determining two phases of a connection destination on a side, wherein the pole transformer on the upstream side of the three-phase distribution line from the pole transformer to determine the two phases of the connection destination A first step of determining two phases of connection destinations of the pole transformer based on reverse phase voltages respectively determined when connected to three sets of two phases of phase distribution lines; and the plurality of pole transformers On the other hand, a second step of sequentially executing the first step from the downstream side to the upstream side of the three-phase distribution line is included.
[Selection] Figure 10

Description

  The present invention relates to a connection phase determination method and a connection phase determination device.

  For example, a pole transformer in which a primary side is connected to a distribution line and a secondary side is connected to a power load is known (for example, Patent Document 1).

JP 2012-216567 A

  A plurality of the above-mentioned pole transformers, including the pole transformers of Patent Document 1, are provided in, for example, a three-phase distribution line to which three-phase AC power is supplied from the upstream side, and among the three phases in the three-phase distribution line Any two phases are connected. For example, there is a possibility that a plurality of the pole transformers are unevenly connected between predetermined phases of a three-phase distribution line, and the degree of unbalance of the three-phase AC voltage is increased due to the uneven connection of the pole transformers.

  The main present invention for solving the above-mentioned problems is that a plurality of three-phase distribution lines to which electric power is supplied from the upstream side is connected to the primary side of any two phases of the three-phase distribution lines, and the power load is connected to the secondary side. A connection phase determination method for determining the two phases of the connection destination on the primary side of the pole transformer, the upstream side of the three-phase distribution line from the pole transformer to determine the two phases of the connection destination, A first step of determining two phases to which the pole transformer is connected, based on the negative phase voltages determined when the pole transformer is connected to three sets of two phases of the three-phase distribution line; and And a second step of sequentially executing the first step from the downstream side to the upstream side of the three-phase distribution line for a plurality of pole transformers.

  Other features of the present invention will become apparent from the accompanying drawings and the description of this specification.

  According to the present invention, the connection phase of the pole transformer can be determined so that the degree of unbalance of the three-phase AC voltage is suppressed.

It is a figure which shows the power distribution system in embodiment of this invention. It is a figure which shows a part of distribution system in embodiment of this invention. It is a figure which shows the connection of the pole transformer with respect to the distribution line in embodiment of this invention. It is a vector diagram which shows the line voltage, line current, and negative phase current when the pole transformer in embodiment of this invention is connected to UV phase. It is a vector diagram which shows a line voltage, a line current, and a negative phase current when the pole transformer in the embodiment of the present invention is connected to the VW phase. It is a vector diagram which shows a line voltage, a line current, and a reverse phase partial current when the pole transformer in the embodiment of the present invention is connected to the WU phase. It is a block diagram which shows the function of the repair apparatus in embodiment of this invention. It is a figure which shows the equipment information table in embodiment of this invention. It is a figure which shows the track | line impedance table in embodiment of this invention. It is a vector diagram for determining the connection phase of the pole transformer in the embodiment of the present invention. It is a flowchart which shows the determination operation | movement of the connection phase by the connection phase determination part in embodiment of this invention. It is a flowchart which shows operation | movement of the repair apparatus in embodiment of this invention. It is a figure which shows the voltage imbalance rate in each node of a distribution line when a pole transformer is connected to each connection phase determined using the repair apparatus in embodiment of this invention. It is a figure which shows the voltage imbalance rate in each node of a distribution line.

  At least the following matters will become apparent from the description of this specification and the accompanying drawings.

=== Distribution system ===
Hereinafter, the power distribution system in the present embodiment will be described with reference to FIG. FIG. 1 is a diagram showing a power distribution system in the present embodiment.

  The distribution system 100 is a power system for supplying power from the substation 200 to, for example, loads R1 to Rn (power load). The distribution system 100 includes a substation 200, a sales office 300, and a distribution line L100, for example, n pole transformers Tr1 to Trn, for example, n loads R1 to Rn. Note that n, which is the number of pole transformers and loads provided in the power distribution system 100, is a positive integer of 2 or more, for example.

  The substation 200 is, for example, a distribution substation that steps down the power supplied from the upstream side and supplies the stepped down power to the distribution line L100. The substation 200 has a distribution transformer 101.

  The distribution transformer 101 is a device that transforms, for example, a primary side voltage at a predetermined transformation ratio and outputs the transformed voltage from the secondary side. The distribution transformer 101 is assumed to have a transformation ratio set so that, for example, a voltage of 66 kilovolts is transformed to a voltage of 6.6 kilovolts. The primary side of distribution transformer 101 is connected to one end of transmission line L200. The power transmission line L200 is a power transmission line for supplying a voltage of 66 kilovolts from an upstream primary substation (not shown) to the downstream substation 200, for example. The secondary side of distribution transformer 101 is connected to one end of distribution line L100.

  The distribution line L100 is a power line for supplying power from the substation 200 (upstream side) to the loads R1 to Rn, and extends from the upstream substation 200 toward the downstream end 103. . Distribution line L100 is a power line for supplying U-phase, V-phase, and W-phase three-phase AC power from substation 200. The distribution line L100 includes a distribution line L1 that supplies U-phase power, a distribution line L2 that supplies V-phase power, and a distribution line L3 that supplies W-phase power. One end on the upstream side of the distribution lines L1 to L3 is connected to the secondary side of the distribution transformer 101, and the other end on the downstream side of the distribution lines L1 to L3 is open, for example.

  One end of the distribution line L100 connected to the distribution transformer 101 is also referred to as a sending end 102. That is, the delivery end 102 is disposed upstream of the pole transformer Tr1 to the pole transformer Trn. Further, the other end downstream of the pole transformer Tr1 to the pole transformer Trn in the distribution line L100 is also referred to as a terminal 103.

  The pole transformer Tr1 to the pole transformer Trn are, for example, transformers that transform the primary side voltage at a predetermined transformation ratio and output the transformed voltage from the secondary side. The pole transformer Tr1 to the pole transformer Trn are set to have a transformation ratio so that, for example, a voltage of 6.6 kilovolts is transformed to a voltage of 100 volts or 200 volts. The primary side of the pole transformer Tr1 to the pole transformer Trn is connected to a predetermined position of the distribution line L100. The primary sides of the pole transformers Tr1 to Trn are connected to any two-phase (two) distribution lines among the distribution lines L1 to L3, respectively. Secondary sides of the pole transformers Tr1 to Trn are connected to the loads R1 to Rn, respectively. The pole transformer Tr1 to the pole transformer Trn are connected to positions corresponding to the nodes P1 to Pn in the distribution line L100, respectively. The pole transformer Tr1 to the pole transformer Trn are connected to the upstream side in the vicinity of the nodes P1 to Pn in the distribution line L100, respectively (FIG. 2).

  The nodes P1 to Pn are positions corresponding to, for example, the positions of the utility poles in the distribution line L100 where, for example, the pole transformer Tr1 to the pole transformer Trn are respectively provided. As many nodes P1 to Pn as the number of pole transformers and loads provided in the distribution system 100 are provided between the sending end 102 and the terminal 103 in the distribution line L100. The nodes P1 to Pn are provided in the order of the nodes P1 to Pn from the downstream side (the end 103 side) to the upstream side (the sending end 102 side) of the distribution line L100. That is, the node P1 is provided on the most downstream side (terminal 103 side) among the nodes P1 to Pn. The node P2 is provided on the upstream side of the node P1 and on the downstream side of the node P3. The node P3 is provided on the upstream side of the node P2 and on the downstream side of the node P4. The node Pn is provided on the most upstream side (the sending end 102 side) among the nodes P1 to Pn.

  The loads R1 to Rn are power loads provided in the distribution system 100. The loads R1 to Rn are connected to the distribution line L100 via the pole transformer Tr1 to the pole transformer Trn, respectively. Each load is a power load that is connected to two distribution lines among the distribution lines L1 to L3 and operates with electric power from the connected distribution lines. In other words, the loads R1 to Rn are supplied with any of the electric power among, for example, the UV phase, the VW phase, and the WU phase.

  Note that the three-phase power load of the distribution system 100, which is different from the loads R1 to Rn, is omitted for convenience of explanation. The three-phase power load is a power load that is connected to all of the distribution lines L1 to L3 and operates with electric power from the connected distribution lines. That is, the three-phase power load is a power load to which all three phases of U phase, V phase, and W phase are supplied.

  For example, a worker for controlling the power distribution system 100 is waiting at the sales office 300. The sales office 300 has the renovation apparatus 1 (connection phase determination apparatus). For example, the refurbishing apparatus 1 may be provided in a control station for controlling the substation 200 and the distribution system 100 other than the sales office 300. The repair device 1 is a device for suppressing a three-phase voltage imbalance (hereinafter also referred to as “voltage imbalance”) in the power distribution system 100.

=== Voltage imbalance ===
Hereinafter, voltage imbalance in the present embodiment will be described with reference to FIG.

  Voltage imbalance means that the amplitude of each line voltage is different or the phase of the line voltage is out of phase in a three-phase AC voltage in which the amplitude of each line voltage is equal and the phase of the line voltage is 120 ° different. It is. The amplitude of each line voltage is different, for example, that the amplitude of the UV phase voltage, the amplitude of the VW phase voltage, and the amplitude of the WU phase voltage are not equal to each other. The phase of the line voltage is shifted, for example, at least one of the phase difference between the UV phase voltage and the VW phase voltage, the phase difference between the VW phase voltage and the WU phase voltage, and the phase difference between the WU phase voltage and the UV phase voltage. The phase difference is not 120 °.

  When a voltage imbalance occurs in the distribution line L100, depending on the degree of the voltage imbalance, for example, the load R1 to the load Rn is not supplied with a voltage at which the load R1 to the load Rn operates normally, and the load R1 to the load Rn. A malfunction of Rn may be caused. Therefore, it is necessary to make the voltage unbalance rate indicating the degree of voltage unbalance in the distribution line L100 relatively small.

The voltage imbalance ratio (ε) is a ratio of a negative phase voltage (hereinafter also referred to as “negative phase divided voltage”) to a positive phase voltage (hereinafter also referred to as “positive phase divided voltage”) as shown in Equation 1. Indicated. The voltage imbalance rate is, for example, the ratio of the negative phase voltage of each node to the positive phase voltage of each node in the distribution system 100, and is obtained for each of the nodes P1 to Pn.

The positive phase voltage and the negative phase voltage are obtained by, for example, a symmetric coordinate method.
For example, as the voltage imbalance rate increases, the voltage amplitude shift and the phase shift increase in each phase (UV phase, VW phase, WU phase) of the distribution line L100. Therefore, it is necessary to control the power distribution system 100 so that the voltage imbalance rate becomes relatively small. In general, the distribution system 100 is desirably controlled such that the voltage imbalance rate is equal to or less than a predetermined ratio.

=== Reverse phase voltage ===
Hereinafter, with reference to FIG. 2, the negative phase divided voltage in the present embodiment will be described. FIG. 2 is a diagram showing a part of the power distribution system in the present embodiment. In addition, although the distribution line L100 is comprised by the three distribution lines of the distribution line L1 thru | or the distribution line L3, it is shown as one distribution line for convenience of explanation.

In the case of a symmetric circuit, the negative phase divided voltage V2 (i + 1) of the node Pi + 1 that is the i + 1-th node from the terminal 103 side of the distribution line L100 is expressed by, for example, Expression 2.

  The negative phase divided voltage V2 (i) indicates the negative phase divided voltage at the node Pi, the negative phase divided current I2 (i + 1) indicates the negative phase divided current at the node Pi + 1, and Z (i) indicates the distribution It is assumed that the impedance (line impedance) of the section Di between the node Pi + 1 and the node Pi in the electric wire L100 is shown. In addition, as the negative phase divided voltage, there are a negative phase voltage of the UV phase, a negative phase voltage of the VW phase, and a negative phase voltage of the WU phase. It is assumed that the reverse phase voltage is shown. In addition, as the negative phase current, there are a U phase negative phase current, a V phase negative phase current, and a W phase negative phase current. It is assumed that the reverse phase current is shown.

Here, Formula 2 is transformed into Formula 4 based on Formula 3.

  Note that I2 (i) represents a reverse phase current at the node Pi. Further, I2tr (i) represents a reverse phase current supplied from the distribution line L100 to the pole transformer Tri and the load Ri. This reverse-phase component current I2tr (i) is a reverse-phase component current generated when the pole transformer Tri and the load Ri are connected to the distribution line L100.

  As shown in Expression 4, the magnitude of the negative phase divided voltage V2 (i + 1) of the node Pi + 1 is determined based on, for example, the negative phase divided current I2tr (i) and the impedance Z (i).

  When determining the two phases to which the pole transformer Tri is connected, the node Pi and the node Pi + 1 correspond to the first position and the second position, respectively.

=== Load connection to distribution line, reverse phase current ===
Hereinafter, with reference to FIG. 3 thru | or FIG. 6, the connection of the load with respect to the distribution line in this embodiment, and a negative phase current are demonstrated.

  FIG. 3 is a diagram illustrating the connection of the pole transformer to the distribution line in the present embodiment. FIG. 4 is a vector diagram showing a line voltage, a line current, and a reverse phase current when the pole transformer in the present embodiment is connected to the UV phase. FIG. 5 is a vector diagram showing a line voltage, a line current, and a reverse phase current when the pole transformer in the present embodiment is connected to the VW phase. FIG. 6 is a vector diagram showing the line voltage, the line current, and the reverse phase current when the pole transformer in the present embodiment is connected to the WU phase.

  4 to 6, Vuv (k), Vwu (k), and Vvw (k) are line voltages between the U phase and the V phase, and line voltages between the W phase and the U phase, respectively. , And the line voltage between the V phase and the W phase. In FIG. 4, Iu (k) uv and Iv (k) uv respectively represent the U-phase line current and the V-phase line current when the pole transformer Trk is connected to the UV phase, and Iu2 (k) uv, Iv2 (k) uv, and Iw2 (k) uv respectively indicate the reverse phase currents of the U-phase, V-phase, and W-phase when the pole transformer Trk is connected to the UV phase, and Iu1 (k) uv, Iv1 (k) uv, and Iw1 (k) uv represent positive phase currents of the U phase, the V phase, and the W phase when the pole transformer Trk is connected to the UV phase, respectively.

  In FIG. 5, Iw (k) vw and Iv (k) vw respectively indicate the W-phase line current and the V-phase line current when the pole transformer Trk is connected to the VW phase, and Iu2 ( k) vw, Iv2 (k) vw, Iw2 (k) vw respectively indicate the reverse phase currents of the U-phase, V-phase, and W-phase when the pole transformer Trk is connected to the VW-phase, and Iu1 ( k) vw, Iv1 (k) vw, and Iw1 (k) vw respectively indicate the positive phase currents of the U phase, V phase, and W phase when the pole transformer Trk is connected to the VW phase. .

  In FIG. 6, Iw (k) wu and Iu (k) wu indicate the W-phase line current and U-phase line current when the pole transformer Trk is connected to the WU phase, respectively, and Iu2 ( k) wu, Iv2 (k) wu, and Iw2 (k) wu respectively indicate U-phase, V-phase, and W-phase reverse phase currents when the pole transformer Trk is connected to the WU phase. k) wu, Iv1 (k) wu, and Iw1 (k) wu respectively indicate the positive phase currents of the U phase, the V phase, and the W phase when the pole transformer Trk is connected to the WU phase. .

  Node Pk (FIG. 3) and node Pk + 1 are the kth and k + 1th nodes from the end 103 side of the distribution line L100, respectively. That is, the node Pk + 1 is a node upstream of the node Pk. The reverse phase current generated by the connection when the pole transformer Trk is connected to the distribution line L1 and the distribution line L2 will be described. Of the pole transformers Tr1 to Trn of the distribution system 100 (FIG. 1), pole transformers other than the pole transformer Trk are not connected to the distribution line L100.

  When the pole transformer Trk is connected to the distribution line L1 and the distribution line L2, for example, the current flowing from the distribution line L1 to the pole transformer Trk via the connection point D1 is represented by the line current Iu ( k) uv (FIG. 4) flows. That is, the line current Iu (k) uv is supplied from the distribution line L1 to the pole transformer Trk via the connection point D1. At this time, the phase difference between the line current Iv (k) uv and the line current Iu (k) uv is 180 °.

  The pole transformer Trk connected to the distribution line L1 (U phase) and the distribution line L2 (V phase) is also referred to as the pole transformer Trk connected to the UV phase of the distribution line L100. To do. Further, connecting the pole transformer Trk to the distribution line L2 (V phase) and the distribution line L3 (W phase) is also referred to as connecting the pole transformer Trk to the VW phase of the distribution line L100. . In addition, connecting the pole transformer Trk to the distribution line L3 (W phase) and the distribution line L1 (U phase) is also referred to as connecting the pole transformer Trk to the WU phase of the distribution line L100. To do.

  When the pole transformer Trk is connected to the UV phase of the distribution line L100, the U-phase reversed current Iu2 (k) uv (FIG. 4) and the V-phase reversed current separated from each other by 120 °. Iv2 (k) uv and W-phase reverse phase current Iw2 (k) uv are generated. The angle θk between Vuv (k) and Iu2 (k) uv is determined according to, for example, the power factor of the pole transformer Trk and the load Rk. The negative phase component current Iu2 (k) uv, the negative phase component current Iv2 (k) uv, and the negative phase component current Iw2 (k) uv are obtained, for example, by a symmetric coordinate method. When the pole transformer Trk is connected to the VW phase of the distribution line L100, the phase is shifted by 120 ° in the same manner as when the pole transformer Trk is connected to the UV phase of the distribution line L100. The negative phase current Iu2 (k) vw (FIG. 5), the negative phase current Iv2 (k) vw of the V phase, and the negative phase current Iw2 (k) vw of the W phase are generated. Further, when the pole transformer Trk is connected to the WU phase of the distribution line L100, the phase is shifted by 120 ° in the same manner as when the pole transformer Trk is connected to the UV phase of the distribution line L100. The negative phase current Iu2 (k) wu (FIG. 6), the negative phase current Iv2 (k) wu of the V phase, and the negative phase current Iw2 (k) wu of the W phase are generated.

  The phase of the reverse phase current when the pole transformer Trk is connected to the distribution line L100 is the line voltage of the distribution lines L1 and L2 depending on which phase the pole transformer Trk is connected to. It will deviate from the phase of Vuv (k). For example, the reverse phase voltage Iu2 (k) uv of the U phase when the pole transformer Trk is connected to the UV phase (FIG. 4), and the U phase when the pole transformer Trk is connected to the VW phase The reverse phase divided voltage Iu2 (k) vw (FIG. 5) and the U-phase reversed voltage divided voltage Iu2 (k) wu (FIG. 6) when the pole transformer Trk is connected to the WU phase have a phase of 120 °. It will shift | deviate one by one (FIG. 10). For example, the phase of the negative phase divided voltage Iu2 (k) vw is 120 ° delayed from the phase of the negative phase divided voltage Iu2 (k) uv, and the phase of the negative phase divided voltage Iu2 (k) wu is the negative phase divided voltage Iu2. (K) 120 ° behind the phase of vw. It should be noted that the phase at the negative phase current Iv2 (k) uv, Iv2 (k) vw, Iv2 (k) wu and the phase at the negative phase current Iw2 (k) uv, Iw2 (k) vw, Iw2 (k) wu. Is the same as the phase in the anti-phase current Iu2 (k) uv, Iu2 (k) vw, Iu2 (k) wu, and the description thereof is omitted.

=== Connection of pole transformer and voltage imbalance ratio ===
Hereinafter, the connection of the pole transformer and the voltage imbalance rate in the present embodiment will be described with reference to FIGS.

  As described above, the voltage imbalance rate is determined according to the magnitude of the reverse phase voltage (Equation 1). For example, when the voltage imbalance rate is made relatively small, the magnitude of the reverse phase divided voltage needs to be made relatively small. The negative phase divided voltage V2 (i + 1) is determined according to the product of the impedance Z (i) and the negative phase divided current I2tr (i) (Formula 4). As described above, the phase of the negative phase current I2tr (i) is determined according to which phase of the pole transformer Tri is connected to the distribution line L100. The magnitude of the negative phase current I2tr (i) is determined according to the utilization factor of the pole transformer Tri. Note that the utilization factor of the pole transformer Tri will be described later. The magnitude of the reverse phase divided voltage V2 (i + 1) is determined according to which phase of the pole transformer Tri is connected to the distribution line L100.

  Therefore, in order to keep the voltage unbalance rate of a predetermined node (for example, node Pi + 1) relatively small, the connection destination of the pole transformer Tri is reduced so that the magnitude of the reverse phase divided voltage V2 (i + 1) becomes small. It is desirable to select a phase.

  Further, from Equation 4, the magnitude of the reverse phase divided voltage (for example, V2 (i + 1)) on the upstream side becomes smaller as the magnitude of the reverse phase divided voltage (for example, V2 (i)) on the downstream side becomes smaller. I can say that. Therefore, when the magnitude of the reverse phase voltage of a predetermined node (for example, node Pi + 1) in the distribution line L100 is relatively small, the reverse phase component on the downstream side (terminal 103 side) of the predetermined line in the distribution line L100. It is necessary to keep the voltage magnitude relatively small.

  Therefore, in order to keep the voltage unbalance rate of the nodes Tr1 to Trn relatively small, the pole transformation is sequentially performed from the downstream side (terminal 103 side) to the upstream side (sending end 102 side) of the distribution line L100. It is desirable to determine the two phases (hereinafter also referred to as “connection phases”) to which the devices Tr1 to Trn are connected.

  In addition, a connection phase is each pole transformer (each each) among UV phase (distribution line L1, L2), VW phase (distribution line L2, L3), and WU phase (distribution line L3, L1) of the distribution line L100. The phase to which (load) is connected. That is, the connection phase indicates any two phases (two lines) among the distribution lines L1 to L3.

=== Capacity of pole transformer, utilization factor of pole transformer ===
Hereinafter, with reference to FIG. 1, the capacity | capacitance and utilization factor of the pole transformer in this embodiment are demonstrated.

  The capacity of the pole transformer is, for example, a predetermined capacity for each of the pole transformer Tr1 to the pole transformer Trn, and is based on, for example, the rating of the pole transformer Tr1 to the pole transformer Trn. Capacity. Here, as the pole transformer Tr1 to the pole transformer Trn, for example, a pillar having a rating that can supply power for the loads R1 to Rn to operate properly to the loads R1 to Rn. It is assumed that an upper transformer is provided. That is, the capacity | capacitance of each pole transformer is defined according to the load amount of load R1 thru | or load Rn, for example.

  The load amount (power load amount) is, for example, an amount corresponding to the power consumed by the loads R1 to Rn, and is determined for each of the loads R1 to Rn. For example, the load amount may be determined based on a power flow supplied from the distribution line L100 to each of the loads R1 to Rn when the loads R1 to Rn are connected to the distribution line L100. . For example, the load amount may be determined based on a measurement result of a smart meter (not shown) that measures power consumption for each of the loads R1 to Rn.

  The utilization factor of the pole transformer is determined by the load R1 to the load R10 from the distribution line L100 via the pole transformer Tr1 to the pole transformer Trn for the respective capacities of the plurality of pole transformers Tr1 to Trn. This is the ratio of power supplied to each, and is determined for each of the plurality of pole transformers. That is, the utilization factor of each pole transformer indicates the ratio of the actual use of each pole transformer with respect to the capacity of each pole transformer. That is, the utilization factor of the pole transformer is determined according to the load amounts of the loads R1 to Rn. The utilization factor of each pole transformer may be determined in advance according to, for example, seasonal (quarter) or hourly power fluctuations in each of the loads R1 to Rn. Further, for example, a smart meter (not shown) for measuring the power consumed by the loads R1 to Rn and storing the measurement result is provided in the distribution system 100, and based on the measurement result by the smart meter, for example, The utilization factor of each pole transformer may be updated every season or every hour. Moreover, the utilization factor of each pole transformer may be determined using a predetermined approximate expression based on, for example, the monthly electricity usage of the customer.

=== Renovation equipment ===
Hereinafter, with reference to FIG. 1, FIG. 7 thru | or FIG. 9, the repair apparatus in this embodiment is demonstrated. FIG. 7 is a block diagram illustrating functions of the repair device according to the present embodiment. FIG. 8 is a diagram showing a facility information table in the present embodiment. FIG. 9 is a diagram showing a line impedance table in the present embodiment.

  The repair device 1 is a device that determines a connection phase of each of the pole transformer Tr1 to the pole transformer Trn in the power distribution system 100. In addition, the method of determining the connection phase of each of pole transformer Tr1 thru | or pole transformer Trn with the repair apparatus 1 is equivalent to the connection phase determination method. The repair device 1 includes, for example, an input unit 11, an output unit 12, a display unit 13, a storage unit 14, a connection phase determination unit 15 (first determination unit, second determination unit), and a control unit 16.

  The input unit 11 is, for example, a keyboard for inputting information to the repair device 1.

  The output unit 12 is, for example, a printer for outputting information to the outside of the repair device 1.

  The display unit 13 is, for example, a monitor for displaying information input to the repair device 1 or displaying information output from the repair device 1.

  The storage unit 14 includes, for example, a first area 141, a second area 142, and a third area 143.

  In the first area 141, for example, a program for operating the repair device 1 is stored. The first region 141 further stores, for example, a program for determining the connection phase of the pole transformer Tr1 to the pole transformer Trn (hereinafter also referred to as “connection phase determination program”). Yes.

  In the second area 142, for example, data indicating the equipment information table T1 (FIG. 8) and data indicating the line impedance table T2 (FIG. 9) are stored. The equipment information table T1 and the line impedance table T2 will be described later.

  In the third area 143, information indicating the variable m and information indicating the variable j are stored. The variable m is a variable indicating the number of pole transformers of the distribution system 100 stored in the equipment information table T1, and for example, based on the equipment information table T1 when the connection phase determination program is started. It shall be set automatically. The variable j is a variable indicating the number of pole transformers for which the connection phase is determined by the connection phase determination unit 15 after the connection phase determination program is started. For example, the connection phase determination program Shall be initialized to zero when is started. The variables m and j will be described later.

  The connection phase determination unit 15 determines the connection phase of each of the pole transformer Tr1 to the pole transformer Trn based on the equipment information table T1 and the line impedance table T2. The connection phase determination unit 15 will be described later.

  The control unit 16 controls the operation of the repair device 1 based on, for example, a program for operating the repair device 1.

=== Equipment information table, Line impedance table ===
Hereinafter, the equipment information table and the line impedance table in the present embodiment will be described with reference to FIGS.

<Facility information table>
In the facility information table T1, information for determining the connection phase of the pole transformer Tr1 to the pole transformer Trn of the power distribution system 100 is associated. In the facility information table T1, the nodes P1 to Pn corresponding to the positions where the pole transformers are connected to the pole transformers Tr1 to Trn and the capacities of the pole transformers, respectively. And the utilization factor of each pole transformer and the connection phase of each pole transformer are associated with each other. The facility information table T1 can be updated by, for example, the input unit 11, the connection phase determination unit 15, and the like.

<Line impedance table>
In the line impedance table T2, the sections D1 to Dn in the distribution line L100 (FIG. 1) and the impedances Z (1) to Z (n) of the sections are associated with each other. The sections D1 to Dn are sections of the distribution line L100 divided by each node. Among the sections D1 to Dn, the section D1 is the most downstream section, and the section Dn is the most upstream section. Therefore, the sections D1 to Dn are sequentially provided from the downstream side to the upstream side of the distribution line L100. For example, a section between the node P1 and the node P2 is a section D1, a section between the node P2 and the node P3 is a section D2, and a section between the node Pn and the sending end 102 is a section Dn. Note that the sections D3 to Dn-1 are sections defined by predetermined nodes as in the sections D1, D2, and Dn.

=== Connection Phase Determination Unit ===
Hereinafter, with reference to FIG.7 and FIG.9, the connection phase determination part in this embodiment is demonstrated.

  The connection phase determination unit 15 determines the connection phase of each of the pole transformer Tr1 to the pole transformer Trn based on the equipment information table T1 and the line impedance table T2.

  The connection phase determination unit 15 operates based on a connection phase determination program stored in the first area 141.

  For example, the connection phase determination unit 15 selects a predetermined column transformer (for example, the column transformer Tri) from which the connection phase is to be determined among the column transformers Tr1 to Trn. The connection phase determination unit 15 moves a predetermined pole transformer, for which the connection phase is determined, from the pole transformer Tr1 on the downstream side (terminal 103 side) of the distribution line L100 toward the upstream side (on the sending end 102 side). Select one by one.

  In addition, the connection phase determination unit 15 includes two pairs of three predetermined pole transformers (for example, the pole transformer Tri) (the UV phase of the distribution line L100, the VW phase of the distribution line L100, and the WU phase of the distribution line L100). ) To the upstream side of the predetermined pole transformer on the upstream side of the node adjacent to the predetermined pole transformer (for example, node Pi + 1) (hereinafter referred to as “the upstream phase of the negative phase transformer”). Each of which is also referred to as “divided voltage”. That is, the connection phase determination unit 15 calculates the reverse phase voltage of the node on the upstream side of the pole transformer that should determine the two phases to be connected. In addition, when the predetermined pole transformer which should determine a connection phase is the pole transformer Trn, the connection phase determination part 15 shall calculate the reverse phase partial voltage in the sending end 102, for example. Note that the negative phase divided voltage of the upstream node when a predetermined pole transformer Tri is connected to the UV phase is defined as a negative phase divided voltage V2 (i + 1) uv. Further, the reverse phase voltage of the upstream node when a predetermined pole transformer Tri is connected to the VW phase is defined as a reverse phase voltage V2 (i + 1) vw. Further, the reverse phase voltage of the upstream node when a predetermined pole transformer Tri is connected to the WU phase is defined as a reverse phase voltage V2 (i + 1) wu. The calculation of the magnitudes of the negative phase divided voltages V2 (i + 1) uv, V2 (i + 1) vw, and V2 (i + 1) wu will be described later.

  Further, the connection phase determination unit 15 minimizes the size of the connection phase of the predetermined pole transformer Tri among the reverse phase divided voltages V2 (i + 1) uv, V2 (i + 1) vw, and V2 (i + 1) wu. Decide in two phases.

  Moreover, the connection phase determination part 15 updates the installation information table T1 based on the determination result about the connection phase of predetermined | prescribed pole transformer Tri.

=== Calculation of reverse phase voltage division, determination of connected phase ===
Hereinafter, with reference to FIG. 10, calculation of the reverse phase divided voltage and determination of the connection phase in the present embodiment will be described. FIG. 10 is a vector diagram for determining the connection phase of the pole transformer in the present embodiment. The negative phase current Iu2 (i) uv, the negative phase current Iu2 (i) wu, and the negative phase current Iu2 (i) vw are connected to the UV transformer, WU phase, and VW phase, respectively. 2 shows a reverse phase current generated when the current is applied, and corresponds to the reverse phase current I2tr (i) in FIG. The negative phase divided voltage V2 (i) is a negative phase divided voltage at the node Pi. The impedance Z (i) is the line impedance of the section Di in the distribution line L100. The anti-phase current I2 (i) is the anti-phase current at the node Pi. The anti-phase voltage V2 (i + 1) uv, the anti-phase voltage V2 (i + 1) wu, and the anti-phase voltage V2 (i + 1) vw are respectively connected to the pole transformer Tri to the UV phase, WU phase, and VW phase. Is the reverse phase voltage at node Pi + 1.

  As described above, the phases of the negative phase current Iu2 (i) uv, the negative phase current Iu2 (i) wu, and the negative phase current Iu2 (i) vw are shifted by 120 °, for example.

Further, the magnitudes of the negative phase current Iu2 (i) uv, the negative phase current Iu2 (i) wu, and the negative phase current Iu2 (i) vw are determined by, for example, (Equation 5).

  In Equation 5, I2tr (i) corresponds to the anti-phase current Iu2 (i) uv, the anti-phase current Iu2 (i) wu, and the anti-phase current Iu2 (i) vw, respectively, Itr (i) Is a line current supplied from the distribution line L100 to the pole transformer Tri. The reference voltage indicates the voltage of the distribution line L100 and is, for example, 6.6 kilovolts. The capacity and the utilization factor are the capacity of the pole transformer Tri and the utilization factor of the pole transformer Tri, respectively (FIG. 8).

  The magnitudes of the negative-phase component current Iu2 (i) uv, the negative-phase component current Iu2 (i) wu, and the negative-phase component current Iu2 (i) vw depend on, for example, the reference voltage, the capacity of the pole transformer Tri, and the utilization factor. It will be determined accordingly (Formula 5).

  In FIG. 10, a vector Z (i) · Iu2 (i) uv, which is the product of the impedance Z (i) and the negative phase current Iu2 (i) uv, the impedance Z (i) and the negative phase current Iu2 (i) wu The vector Z (i) · Iu2 (i) wu, which is the product, and the phase of the vector Z (i) · Iu2 (i) vw, which is the product of the impedance Z (i) and the antiphase current Iu2 (i) vw, respectively, For example, the inductive component of impedance Z (i) is delayed by a predetermined angle with respect to the phases of the negative phase current Iu2 (i) uv, the negative phase current Iu2 (i) wu, and the negative phase current Iu2 (i) vw. It becomes.

  The magnitudes of the vectors Z (i) · Iu2 (i) uv, the vectors Z (i) · Iu2 (i) wu, and the vectors Z (i) · Iu2 (i) vw are, for example, the impedance Z (i). It will be determined depending on the size.

Here, Expression 4 can be transformed as Expression 6 below.

  In FIG. 10, when the starting point of the negative phase divided voltage V2 (i) is the origin E100 where the real axis and the imaginary axis intersect, the result of adding the second term and the third term on the right side in Equation 6 is, for example, This corresponds to a vector (not shown) having the start point as the origin E100 and the end point as the point E0. Further, the negative phase divided voltage (vector) V2 (i + 1), which is the result of adding the first term on the right side of Equation 6, is the negative phase divided voltage V2 (i + 1) with the start point as the origin E100 and the end point as one of the points E1 to E3. ) Corresponding to any one of vw, V2 (i + 1) uv, and V2 (i + 1) wu.

  For example, the reverse phase voltage V2 (i + 1) when the pole transformer Tri is connected to the VW phase corresponds to the reverse phase voltage (vector) V2 (i + 1) vw with the start point as the origin E100 and the end point as E1. Will be. For example, the reverse phase divided voltage V2 (i + 1) when the pole transformer Tri is connected to the UV phase corresponds to the reverse phase divided voltage (vector) V2 (i + 1) uv having the start point as the origin E100 and the end point as E2. Will be. For example, the reverse phase divided voltage V2 (i + 1) when the pole transformer Tri is connected to the WU phase corresponds to the reverse phase divided voltage (vector) V2 (i + 1) wu having the start point as the origin E100 and the end point as E3. Will be.

  The connection phase determination unit 15 calculates the magnitudes of the reverse phase divided voltages V2 (i + 1) uv, V2 (i + 1) vw, and V2 (i + 1) wu using, for example, the vector diagram shown in FIG. Note that information about the distribution system 100 for calculating the reverse phase divided voltages V2 (i + 1) uv, V2 (i + 1) vw, and V2 (i + 1) wu is stored in, for example, the second region 142, and the connection phase The determination unit 15 also calculates each negative phase divided voltage using the information. Then, in FIG. 10, the connection phase determination unit 15 has the smallest value of the negative phase divided voltage V2 (i + 1) vw among the negative phase divided voltages V2 (i + 1) uv, V2 (i + 1) vw, and V2 (i + 1) wu. Therefore, the connection phase of the pole transformer Tri is determined to be the VW phase.

=== Operation of Connection Phase Determination Unit ===
Hereinafter, with reference to FIG. 11, the operation of the connection phase determination unit in the present embodiment will be described. FIG. 11 is a flowchart showing the connection phase determination operation by the connection phase determination unit in the present embodiment.

  A description will be given from the time when the connection phase determination program stored in the first area 141 is started and the connection phase determination operation by the connection phase determination unit is started.

  The connection phase determination unit 15 determines whether or not the variable j is less than the variable m (step S1). That is, the connection phase determination unit 15 determines whether or not there is a pole transformer in which the connection phase is not determined in the distribution system 100 that determines the connection phase.

  For example, when it is determined that there is a pole transformer whose connection phase is not determined in the distribution system 100 (when it is determined that the variable j is less than the variable m) (YES in step S1), the connection phase The determination part 15 selects the pole transformer which determines the connection phase in the facility information table T1 in the distribution system 100 (third step) (step S2). The connection phase determination unit 15 sets the most downstream pole transformer in the facility information table T1 among the pole transformers for which the connection phase is not determined as the pole transformer that determines the connection phase. select. In step S2, it is assumed that the pole transformer Tri (i is an integer of 1 to n) is selected.

  As described above, the connection phase determining unit 15 calculates the magnitudes of the reverse phase divided voltages V2 (i + 1) uv, V2 (i + 1) vw, and V2 (i + 1) wu (fourth to sixth steps) (steps). S3).

  The connection phase determination unit 15 determines the two phases to which the predetermined pole transformer Tri is connected so that the magnitude of the reverse phase divided voltage V2 (i + 1) at the node Pi + 1 is minimized (fifth step). (Step S4).

  For example, when the negative phase divided voltages V2 (i + 1) uv, V2 (i + 1) vw, and V2 (i + 1) wu correspond to the respective vectors shown in FIG. The two phases to which the device Tri is connected are determined to be the VW phase. For example, when determining the two-phase connection destination of the most downstream pole transformer Tr1 among the pole transformers Tr1 to Trn (when i is 1), the negative phase divided voltage V2 (2) uv , V2 (2) vw, V2 (2) wu may be equal. In this case, the connection phase determination unit 15 may determine the two phases to which the pole transformer Tr1 is connected as a predetermined two phase.

  The connection phase determination unit 15 sets the facility information table so that the connection phase associated with the pole transformer selected as the pole transformer for determining the connection phase becomes the determined connection phase. T1 is updated (step S5).

  The connection phase determination unit 15 adds 1 to the variable j (step S6), and then performs the determination in step S1 again.

  In the determination of step S1 described above, for example, when it is not determined that there is a pole transformer for which the connection phase is not determined in the distribution system 100 (when the variable j is not determined to be less than the variable m) ), The connection phase determination operation by the connection phase determination unit 15 ends. Steps S2 to S4 correspond to the first step. Moreover, it is equivalent to a 2nd step to perform said step S2 thru | or S4 sequentially toward the upstream from the downstream in the distribution line L100 with respect to pole transformer Tr1 thru | or Trn.

=== Operation of the repair device ===
Hereinafter, with reference to FIG. 12, operation | movement of the repair apparatus in this embodiment is demonstrated. FIG. 12 is a flowchart showing the operation of the repair device according to the present embodiment.

  A description will be given from the case where the program for operating the repair device 1 stored in the first area 141 is started and the control operation of the repair device 1 by the control unit 16 is started.

  The control unit 16 receives input information (step S21). The input information is information necessary for determining the connection phase of each of the pole transformer Tr1 to the pole transformer Trn, such as the equipment information table T1. The input information may be input from the input unit 11, for example, or may be input using a recording medium (not shown) such as an optical disk. In addition, for example, information necessary for determining the connection phase of each of the pole transformer Tr1 to the pole transformer Trn may be stored in the repair device 1 in advance.

  The control unit 16 activates the connection phase determination program, and, as described above, the connection phase determination unit 15 performs the pole transformers Tr1 to Tr on the distribution system 100 based on the facility information table T1. The connection phase of the transformer Trn is determined (step S22).

  The control unit 16 causes the display unit 13 to display information in which the pole transformers Tr1 to Trn of the power distribution system 100 and the connection phases of the pole transformers are associated with each other, for example, 12 and so on.

=== Voltage imbalance rate ===
Hereinafter, with reference to FIG.13 and FIG.14, the voltage imbalance rate when the connection phase of a pole transformer is determined using the repair apparatus in this embodiment is demonstrated.

  FIG. 13 is a diagram illustrating the voltage imbalance rate at each node of the distribution line when the pole transformer is connected to each connection phase determined using the repair device according to the present embodiment. FIG. 14 is a diagram illustrating a voltage imbalance rate at each node of the distribution line. FIG. 13 and FIG. 14 are diagrams showing the voltage imbalance rate of each node obtained by simulation, for example. In FIG. 13 and FIG. 14, the voltage imbalance rate at the nodes P1 to P10 is shown for convenience of explanation.

  When the connection phase of the pole transformers Tr1 to Tr10 is determined using the repair device 1, the magnitude of the reverse phase voltage at each node of the distribution line L100 becomes relatively small, so that the voltage non-voltage at the nodes P1 to P10 The equilibrium rate will be kept relatively small (FIG. 13).

  On the other hand, when the connection phase of the pole transformers Tr1 to Tr10 is determined without using the repair device 1, for example, the magnitude of the reverse phase voltage at each node of the distribution line L100 becomes relatively large, and the nodes P1 to The voltage imbalance rate at P10 is relatively large (FIG. 14).

  From the above, for example, the voltage imbalance rate (FIG. 13) in the nodes P1 to P10 when the connection phase is determined by the renovation apparatus 1 is the node P1 to P1 when the connection phase is determined without using the refurbishment apparatus 1. The voltage unbalance rate at P10 (FIG. 14) will be kept smaller.

  As described above, the refurbishment apparatus 1 includes a plurality of primary lines connected to any two of the three phases of the distribution line L100 to which power is supplied from the upstream side, and loads R1 to Rn connected to the secondary side. The two-phase connection destinations on the primary side of the pole transformers Tr1 to Trn are determined. The refurbishing apparatus 1 has a reverse phase divided voltage V2 (i + 1) on the upstream side (the sending end 102 side) of the distribution line L100 with respect to the pole transformer (for example, the pole transformer Tri) for which two phases to be connected are to be determined. Based on uv, the negative phase divided voltage V2 (i + 1) vw, and the negative phase divided voltage V2 (i + 1) wu, the two phases to which the pole transformer Tri is connected are determined. The repair device 1 sequentially determines the two phases of the connection destinations of the pole transformers Tr1 to Trn from the downstream side (the end 103 side) to the upstream side (the sending end 102 side) of the distribution line L100. Therefore, by suppressing the negative phase voltage of the downstream node (for example, node Pi) to be relatively small, the negative phase voltage of the upstream node (for example, node Pi + 1) relative to the downstream node is relatively small. (Equation 4). Therefore, the repair device 1 can determine the two phases to which the pole transformers Tr1 to Trn are connected so that the voltage imbalance of each node in the distribution line L100 is relatively small. Further, since it is not necessary to provide, for example, a voltage compensation device (not shown) for reducing the voltage unbalance rate of the distribution line L100 in the distribution system 100, the cost for reducing the voltage unbalance rate of the distribution line L100. Can be reduced. Further, since it is not necessary to provide and control the above-described voltage compensation device in the distribution system 100, the voltage management work of the distribution system 100 for making the voltage unbalance rate of the distribution line L100 3% or less becomes easy.

  In addition, the refurbishing apparatus 1 selects a pole transformer that should determine the two phases to be connected. Thereafter, the refurbishment apparatus 1 has a reverse phase divided voltage V2 (i + 1) uv and a reverse phase divided voltage V2 (upstream of the selected line transformer (for example, the pole transformer Tri) on the upstream side of the distribution line L100). i + 1) vw and reverse phase divided voltage V2 (i + 1) wu are calculated. Thereafter, the renovation device 1 selects the above-described selection based on the calculated negative phase divided voltage V2 (i + 1) uv, negative phase divided voltage V2 (i + 1) vw, and negative phase divided voltage V2 (i + 1) wu. The two phases of the connection destination of the pole transformer (for example, pole transformer Tri) are determined. With these configurations, the two phases of the connection destination of the pole transformer that should determine the two phases of the connection destination can be reliably and sequentially determined from the downstream side to the upstream side of the distribution line L100. Therefore, the two phases to which the pole transformers Tr1 to Trn are connected can be determined so that the degree of unbalance of the three-phase AC voltage in the distribution line L100 is relatively small.

  Further, the refurbishing apparatus 1 uses the two-phase connection destination of the pole transformer (for example, the pole transformer Tri) to determine the two-phase connection destination, the negative phase divided voltage V2 (i + 1) uv, and the negative phase division voltage. V2 (i + 1) vw and negative phase divided voltage V2 (i + 1) wu are determined to be the two phases having the lowest negative phase divided voltage. With this configuration, the refurbishing device 1 can reliably reduce the reverse phase voltage of each node in the distribution line L100. Therefore, the two phases to which the pole transformers Tr1 to Trn are connected can be determined so that the degree of unbalance of the three-phase AC voltage in the distribution line L100 is relatively small.

  Further, the refurbishing apparatus 1 is provided between the node Pi on the downstream side of the pole transformer (for example, the pole transformer Tri) to determine the two phases to be connected and the node Pi + 1 on the upstream side of the pole transformer. The negative phase divided voltage V2 (i + 1) uv, the negative phase divided voltage V2 (i + 1) vw, and the negative phase divided voltage V2 (i + 1) wu at the node Pi + 1 are calculated based on the impedance Z (i). With this configuration, the refurbishing device 1 sets the impedance Z (i) of the distribution line L100 to the negative phase divided voltage V2 (i + 1) uv, the negative phase divided voltage V2 (i + 1) vw, and the negative phase divided voltage V2 (i + 1) wu. It can be reflected in the calculation result. Therefore, it is possible to improve the calculation accuracy of the negative phase divided voltage at each node of the distribution line L100. Therefore, the two phases to which the pole transformers Tr1 to Trn are connected can be determined so that the degree of unbalance of the three-phase AC voltage in the distribution line L100 is relatively small.

  Further, the refurbishing apparatus 1 has an impedance Z (i) and a pole transformer (for example, a pole transformer Tri) to determine two phases to be connected to the UV phase, the VW phase, and the WU phase of the distribution line L100, respectively. Based on the product of the negative-phase component current Iu2 (i) uv, the negative-phase component current Iu2 (i) vw, and the negative-phase component current Iu2 (i) wu generated when connected, the negative-phase component voltage V2 (i + 1) ) Uv, reversed-phase divided voltage V2 (i + 1) vw, reversed-phase divided voltage V2 (i + 1) wu are calculated. With this configuration, the refurbishment apparatus 1 converts the negative phase divided current Iu2 (i) uv, the negative phase divided current Iu2 (i) vw, the negative phase divided current Iu2 (i) wu into the negative phase divided voltage V2 (i + 1) uv, This can be reflected in the calculation result of the negative phase divided voltage V2 (i + 1) vw and the negative phase divided voltage V2 (i + 1) wu. Therefore, the calculation accuracy of the reverse phase divided voltage at each node of the distribution line L100 can be further improved. Therefore, the two phases to which the pole transformers Tr1 to Trn are connected can be determined so that the degree of unbalance of the three-phase AC voltage in the distribution line L100 is relatively small.

  In addition, the refurbishing apparatus 1 has a capacity of the pole transformer predetermined for each pole transformer Tr1 to Trn and a utilization factor of the pole transformer determined according to the load amount of the loads R1 to Rn. Based on the product, a negative phase current Iu2 (i) uv, a negative phase current Iu2 (i) vw, and a negative phase current Iu2 (i) wu are calculated. With this configuration, the renovation apparatus 1 calculates the load amounts of the loads R1 to Rn by calculating the negative phase divided voltage V2 (i + 1) uv, the negative phase divided voltage V2 (i + 1) vw, and the negative phase divided voltage V2 (i + 1) wu. Can be reflected. Therefore, the calculation accuracy of the reverse phase divided voltage at each node of the distribution line L100 can be further improved. Therefore, the two phases to which the pole transformers Tr1 to Trn are connected can be determined so that the degree of unbalance of the three-phase AC voltage in the distribution line L100 is relatively small. Further, the complicated calculation for calculating the power flow from the distribution line L100 to the pole transformers Tr1 to Trn is omitted, and the load amount of the loads R1 to Rn is set to the reverse phase divided voltage V2 (i + 1) uv, the reverse phase. This can be reflected in the calculation results of the divided voltage V2 (i + 1) vw and the reverse phase divided voltage V2 (i + 1) wu. Therefore, the two phases to which the pole transformers Tr1 to Trn are connected can be determined quickly and at low cost.

  The present embodiment is intended to facilitate understanding of the present invention, and is not intended to limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and the present invention includes equivalents thereof.

  In the present embodiment, for example, it has been described that the two phases to be connected to the pole transformer Tri are determined based on the reverse phase voltage of the UV phase, the reverse phase current of the U phase, and the like (FIG. 10). It is not limited to this. For example, the two phases to which the pole transformer Tri is connected are determined based on the reverse phase voltage of the VW phase, the negative phase voltage of the WU phase, the negative phase current of the V phase, and the negative phase current of the W phase. It is good as well.

DESCRIPTION OF SYMBOLS 1 Repair apparatus 15 Connection phase determination part 200 Substation 300 Sales office L1, L2, L3, L100 Distribution line R1, R2, R3, Rn Load Tr1, Tr2, Tr3, Trn Pillar transformer

Claims (7)

The primary side connection destination of a plurality of pole transformers in which the primary side is connected to any two of the three phases of the three-phase distribution line to which power is supplied from the upstream side, and the power load is connected to the secondary side A connection phase determination method for determining two phases of
Reverse phase determined when the pole transformer is connected to three sets of two phases of the three-phase distribution line on the upstream side of the three-phase distribution line from the pole transformer that should determine the two phases of the connection destination A first step of determining two phases of connection destination of the pole transformer based on the voltage;
And a second step of sequentially executing the first step from the downstream side of the three-phase distribution line toward the upstream side with respect to the plurality of pole transformers. The first step includes
A third step of selecting a pole transformer to determine the two phases to be connected;
A fourth step of calculating the reverse phase voltage on the upstream side of the three-phase distribution line from the pole transformer selected in the third step;
5. A fifth step of determining two phases of connection destinations of the pole transformer selected in the third step based on a calculation result of the fourth step. 5. Connection phase determination method. The fifth step includes
The connection phase determination method according to claim 2, wherein the two phases to be connected to the pole transformer selected in the third step are determined to be the two phases with the minimum reverse phase voltage. The fourth step includes
A first position downstream of the pole transformer selected in the third step in the three-phase distribution line, and a first position upstream of the pole transformer selected in the third step in the three-phase distribution line. 4. The connection phase determination method according to claim 2, wherein a negative phase voltage at the second position is calculated based on a line impedance between the two positions. 5. The fourth step includes
The negative phase voltage at the second position is calculated based on the product of the line impedance and the negative phase current generated when the pole transformer selected in the third step is connected to the three-phase distribution line. The connection phase determination method according to claim 4, wherein: The fourth step includes
Based on the product of the capacity of the pole transformer predetermined for each of the plurality of pole transformers and the utilization factor of the pole transformer determined according to the amount of power load of the power load, the reverse The connection phase determination method according to claim 5, further comprising a sixth step of calculating a phase current. The primary side connection destination of a plurality of pole transformers in which the primary side is connected to any two of the three phases of the three-phase distribution line to which power is supplied from the upstream side, and the power load is connected to the secondary side A connected phase determining device for determining two phases of
Reverse phase determined when the pole transformer is connected to three sets of two phases of the three-phase distribution line on the upstream side of the three-phase distribution line from the pole transformer that should determine the two phases of the connection destination A first determination unit that determines the two phases of the connection destination of the pole transformer based on the voltage;
Based on the determination result of the first determination unit, from the downstream side of the three-phase distribution line toward the upstream side, a second determination unit that sequentially determines two phases of connection destinations of the plurality of pole transformers;
A connection phase determining device comprising:

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