JP2002112453A - Loop distributing circuit, method for determining accident zone in the same and method for controlling switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately control switches in each power supplied unit without communication lines between a service office of a power company and the power supplied units in a loop distributing circuit. SOLUTION: The loop distributing circuit connects a loop power line L coupling a trunk F1 and a spare line F2 in a distributing system with the power supplied units U1-U3. In the loop distributing circuit, the power supplied units U1-U3 individually provide: accident zone determining devices R1-R3 inputting outputs from the first and the second accident detectors D11-D13 and D21-D23 in themselves and from accident detectors in neighbor power supplied units, and determining accident zones; and switch controllers C1-C3 isolating accident zones from sound zones based on the determination by the accident zone determining devices, controlling the switches in themselves to accept restart of transmitting power to the sound zones.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a loop distribution circuit,
The present invention relates to an accident section determination method and a switch control method.

[0002]

2. Description of the Related Art As a power distribution circuit with improved power supply reliability, a plurality of power receiving units are provided in the middle of a loop circuit whose one end is connected to a main line of a power distribution system and the other end is connected to a backup line of the power distribution system. A loop power distribution circuit having a connected configuration is used.

Each power receiving unit used in this loop power distribution circuit includes a first and a second switch connected in series to each other, and a circuit for interconnecting the first and the second switch. A transformer having a primary side connected and a secondary side connected to a consumer load, and a current provided through the first and second switches respectively for the first and second switches. First and second detecting accidents
In each power receiving unit, the first switch is located on the main line side of the distribution system, and the series circuit of the first and second switches is inserted in series in the loop circuit. Connected to the loop circuit.

[0004] Among the power receiving units connected to the loop circuit, the second switch of the power receiving unit on the side of the auxiliary line arranged near the auxiliary line is kept open at the time of normal operation, and the other switch is opened. All switches are normally kept closed. The switches other than the second switch of the power receiving unit on the spare line side end are configured to automatically close when a voltage is applied through the loop circuit and to automatically open when the voltage of the loop circuit disappears. Have been.

[0005] The loop circuit is divided into a plurality of sections by switches of each power receiving unit. When an accident occurs in a part of the loop circuit, the switch of the power receiving unit adjacent to the fault point is opened to open the circuit. The section can be separated from the healthy section. Power can be supplied from the backup line side to the healthy section on the backup line side disconnected from the main line due to the occurrence of the accident by turning on the second switch of the backup line side end power receiving unit. Also, when the main line goes out of power, the first end of the main line side power receiving unit
By turning on the second switch of the auxiliary power line side end power receiving unit in a state where the switch is opened and the loop electric circuit is disconnected from the main line, power can be supplied to each power receiving unit from the auxiliary power line side.

[0006] As described above, a loop power distribution circuit in which a loop power path is provided so as to connect between a main line and a backup line and a power receiving unit is connected in the middle thereof is called a π loop power distribution circuit.

In the above loop power distribution circuit,
It is necessary to control the switching provided in each power receiving unit promptly and accurately in cooperation with each other for separation of an accident point and retransmission. Therefore, in a conventional power distribution circuit of this type, a communication line is used to connect a master station provided at a business office of a power company and a slave station provided at each power receiving unit with a communication line. By performing communication, an accident section is located, the located accident section is separated from a healthy section, and a switch of a predetermined power receiving unit is controlled so that power is retransmitted only to a healthy section.

[0008]

As described above, in the conventional loop power distribution circuit, in order to control the switch of each power receiving unit, a master station of a business office of a power company and a slave station of each power receiving unit are connected. Since the communication lines need to be connected between them, there has been a problem that equipment costs are high.

SUMMARY OF THE INVENTION It is an object of the present invention to grasp the status of an accident in each power receiving unit only by exchanging accident information between power receiving units without connecting a master station and a slave station by a communication line. It is another object of the present invention to provide a loop power distribution circuit capable of performing switching control of a switch.

Another object of the present invention is to provide a fault section determination method for determining a fault section in each power receiving unit of the loop power distribution circuit.

Still another object of the present invention is to provide a switch control method for controlling a switch of each charging unit of a loop power distribution circuit.

[0012]

SUMMARY OF THE INVENTION The present invention is directed to a loop power distribution circuit. In the loop power distribution circuit targeted by the present invention, a first and a second switch connected in series to each other,
A transformer having a primary side connected to a circuit connecting the first and second switches and a secondary side connected to a load of a customer, and a transformer provided for the first and second switches, respectively. A power receiving unit having first and second fault detectors for detecting faults from currents flowing through the first and second switches, respectively, is provided so as to connect between a main line and a backup line of the power distribution system. Are installed in the middle of the loop circuit, and the first and second switches of each power receiving unit are inserted in series into the loop circuit with the first switch positioned on the main line side, and connected to the spare line. The second switch of the power receiving unit arranged closest to the power receiving unit is normally kept open, and all other switches are normally kept closed.

According to the present invention, the output of the first and second fault detectors in the own power receiving unit and the output of the fault detector provided for the switch in the adjacent power receiving unit are provided for each power receiving unit. And an accident section determiner that determines an accident section using the input as an input, and the accident section determined by the accident section determiner is separated from the healthy section, and the power receiving unit in its own power receiving unit is allowed to resume power transmission to the healthy section. And a switch control device for controlling the first and second switches.

As described above, each power receiving unit is provided with the faulty section determining device and the switch control device, and the faulty section is separated from the healthy section according to the determination result by the faulty section determining device, and the power transmission to the healthy section is performed. When the first and second switches of each power receiving unit are controlled so as to allow the restart, the switches are accurately controlled for each power receiving unit to separate the faulty section and retransmit power to the healthy section. And can be performed. Therefore, there is no need to connect the master station provided at the sales office of the electric power company and the slave stations provided at each power receiving unit by a communication line, so that the cost required for the equipment can be reduced.

The present invention is also directed to an accident section determination method for determining which section is an accident section when an accident occurs in the loop power distribution circuit.

According to the determination method of the present invention, an accident provided to a switch closer to each power receiving unit among the first and second accident detectors in the power receiving unit disposed adjacent to each power receiving unit is provided. The detector is used as an adjacent accident detector for judging an accident section. The output of the adjacent accident detector is taken into each power receiving unit through a communication line, and both the first and second accident detectors in each power receiving unit detect an accident. When no accident has been detected and the adjacent unit accident detector has not detected an accident, it is determined that an accident has not occurred in each power receiving unit and in the adjacent power receiving unit. When only one of the first and second accident detectors in each power receiving unit detects an accident, it is determined that the accident is in each power receiving unit, and the first and second accidents in each power receiving unit are determined. If both accident detectors detect an accident and there is an adjacent accident detector that has not detected the accident, the distance between the adjacent power receiving unit with the adjacent accident detector that has not detected the accident and each power receiving unit Circuit is determined to have an accident. Furthermore, the first in each power receiving unit
And the second accident detector detects an accident, and when the adjacent accident detector detects an accident, it is determined that the accident is not an accident in each of the power receiving units and the adjacent power receiving unit. Neither the first nor the second accident detector in the unit has detected an accident, and there is an adjacent accident detector that is detecting the accident when the adjacent accident detector is detecting the accident. It is determined that there is an accident between the power receiving units and the power receiving units.

When the accident section is determined as described above,
The fault section can be determined in each power receiving unit without collecting the fault information in a large number of power receiving units arranged in the loop circuit to the master station. Can be controlled accurately.

The present invention is also directed to a switch control method for controlling a switch of each power receiving unit when an accident occurs in the loop power distribution circuit.

In the switch control method according to the present invention, the first power receiving unit in the adjacent power receiving unit arranged adjacent to each power receiving unit is provided.
And an accident detector provided for a switch closer to each power receiving unit among the second accident detectors as an adjacent accident detector for judging an accident section, and outputting an output of the adjacent accident detector through a communication line. Take in each power receiving unit.

The control method of the switch in the power receiving unit is as follows.
It differs depending on where the power receiving unit is arranged. In this specification, the power receiving unit arranged closest to the main line is called a main line end power receiving unit, and the power receiving unit arranged closest to the backup line is called a backup line side end power receiving unit. Further, at least one of the power receiving units disposed between the main line side end power receiving unit and the backup line side end power receiving unit.
One power receiving unit is called an intermediate power receiving unit. The control method of the switch in these power receiving units is as follows.

In the main line side end power receiving unit disposed closest to the main line, the first and second power receiving units are connected when the main line is cut off.
The step of opening the switch, and neither of the first and second accident detectors in the own power receiving unit nor the adjacent accident detector in the adjacent power receiving unit has detected an accident, and When charging on the main line side is confirmed within a set time after the main line power failure, the first and second power receiving units of the own power receiving unit are checked.
Is turned on, neither the first and second fault detectors in the own power receiving unit nor the adjacent fault detector in the adjacent power receiving unit have detected any fault, and the main line is not detected. If charging on the main line cannot be confirmed even after a set time elapses after the power failure, the first of its own power receiving unit
Locking the switch of the second switch, the second switch confirms the charging of the preselection side and then closes, and only one of the first and second fault detectors of its own power receiving unit detects an accident. A step of locking the closing of the first and second switches of the own power receiving unit during detection, and both the first and second accident detectors in the own power receiving unit detect an accident,
And when the adjacent accident detector in the adjacent power receiving unit does not detect an accident, locks the closing of the second switch of the own power receiving unit, but the first switch operates when the voltage of the main line is restored. The mains voltage is reduced when both the first and second accident detectors in the own power receiving unit and the adjacent accident detector in the adjacent power receiving unit detect an accident. After the recovery, the first and second switches of the own power receiving unit are turned on.

Also, in the auxiliary power line side end receiving unit arranged closest to the auxiliary line, the process of opening the first switch when the main line is interrupted, and the first power receiving unit in the own power receiving unit.
Neither the fault detector nor the second fault detector and the adjacent fault detector in the adjacent power receiving unit have detected any fault, and confirm that the main line has been charged within the set time after the main line power failure. Then, the first switch in the own power receiving unit is turned on, and both the first and second accident detectors in the own power receiving unit and the adjacent accident detector in the adjacent power receiving unit cause an accident. Is not detected, and if charging on the main line cannot be confirmed even after a set time has elapsed after the main line has failed, the first and second opening / closing of the own power receiving unit after confirming the charging of the spare line And turning on the first and second switches of the own power receiving unit when only one of the first and second fault detectors of the own power receiving unit detects an accident. The locking process and the power receiving unit When both the first and second accident detectors have not detected an accident and the adjacent accident detector in the adjacent power receiving unit has detected an accident, the first switch in the own power receiving unit has been detected. Locking is performed, and the second switch performs a process of closing after confirming charging on the spare line side.

Further, in the intermediate power receiving unit disposed between the main line side end power receiving unit and the backup line side end power receiving unit, a process of opening the first and second switches when a power failure occurs, After confirming charging when neither the first and second fault detectors in the unit nor the adjacent fault detectors in the adjacent power receiving units on both sides detect an accident, the first power receiving unit of the own power receiving unit is checked. Turning on the first and second switches and the first and second switches of the own power receiving unit when only one of the first and second fault detectors of the own power receiving unit detects an accident. The process of locking the switching of the switch and the first and second fault detectors in the own power receiving unit both detect a fault, and the adjacent fault detector in the adjacent power receiving unit arranged on the spare line side Has not detected an accident Locking the closing of the second switch of the power receiving unit, the first switch is turned on after confirming charging, and both the first and second accident detectors in the own power receiving unit and both sides A step of turning on the first and second switches of the own power receiving unit after confirming charging when any of the adjacent accident detectors in the adjacent power receiving unit arranged in the power receiving unit detects an accident; When both the first and second accident detectors in the own power receiving unit have not detected an accident and the adjacent accident detector of the adjacent power receiving unit arranged on the main line side has detected the accident. The first switch in the own power receiving unit is locked from being turned on, and the second switch is turned on after confirming charging.

By performing the above control, the accident section can be separated from the healthy section when an accident occurs,
When the voltage of the main line recovers, power can be supplied from the main line to the healthy section. If an accident occurs in or between units in the middle of the loop distribution circuit and there is a healthy section where power cannot be supplied from the main line, power can be supplied to the healthy section from the backup line.

The present invention is also applicable to a case where only two power receiving units are installed in the middle of a loop electric circuit. In this case, the process of opening the first and second switches when the main line is interrupted, as in the case where three or more power receiving units are installed, at the main line side end power receiving unit disposed near the main line. Neither the first nor the second accident detector in the own power receiving unit nor the adjacent accident detector in the adjacent power receiving unit has detected an accident, and is set after the mains power failure. When the mains side charging is confirmed within the set time, the first and second switches of the own power receiving unit are turned on, and both the first and second accident detectors in the own power receiving unit and the adjacent power receiving unit are turned on. Neither of the adjacent accident detectors in the area has detected an accident, and if charging on the main line cannot be confirmed even after the set time has elapsed after the main line power failure, the first of its own power receiving unit Locks the closing of the switch, but the The switch is a process to introduce after confirming the primaries side charge, first and second self-powered units
Locking the first and second switches of the own power receiving unit when only one of the fault detectors detects the fault, and the first and second faults in the own power receiving unit When both of the detectors detect an accident, and the adjacent accident detector in the adjacent power receiving unit does not detect an accident, the second switch of the own power receiving unit is locked, but the first switch is closed. The detector is turned on after confirming the mains voltage, and both the first and second fault detectors in its own power receiving unit and the adjacent fault detector in the adjacent power receiving unit detect an accident. And then turning on the first and second switches of the own power receiving unit after confirming the mains side charging.

In the power receiving unit on the backup line side located near the backup line, the process of opening the first switch when the main line is interrupted, and the first and second accidents in the own power receiving unit Neither the detector nor the adjacent accident detector in the adjacent power receiving unit has detected an accident, and if it is confirmed that the main line has been charged within the set time after the main line power outage, it will receive its own power. When the first switch in the unit is turned on, both the first and second accident detectors in the own power receiving unit and the adjacent accident detector in the adjacent power receiving unit have detected an accident. And when the charging of the main line cannot be confirmed even after a set time elapses after the power failure of the main line, the process of turning on the first and second switches of the own power receiving unit after confirming the charging of the backup line And the first of its own power receiving unit Locking only the first and second switches of the own power receiving unit when only one of the second accident detectors detects an accident; and first and second switches in the own power receiving unit. Locking of the first switch in its own power receiving unit is locked when both of the two accident detectors have not detected an accident and the adjacent accident detector in the adjacent power receiving unit has detected an accident. However, the second switch is turned on when the charging of the spare line is confirmed.

[0027]

FIG. 1 shows an example of the configuration of a loop power distribution circuit according to the present invention. In FIG.
Reference numeral 2 denotes a main line and a backup line drawn from a power substation (not shown) of the distribution system. One end of each of the main line F1 and the spare line F2 is connected to a transformer of a power supply substation of the same system or a different system through a circuit breaker.

L is a loop circuit, one end of which is connected to the main line F1 and the other end of which is connected to the spare line F2. The loop circuit L is composed of a distribution line connecting the main line to a customer closest to the main line, between adjacent customers, a customer closest to the backup line and the backup line, and a line in each customer. It is composed of a premises bus and the like.

U1 to U3 are three power receiving units arranged along the loop circuit L and connected to the loop circuit.

More specifically, U1 is a main line side power receiving unit. The power receiving unit U1 is connected to the first and second switches SW11 and SW21 connected in series with each other, and to the switches SW11 and SW21. First and second fault detectors D11 and D12 for detecting presence / absence of a fault (short circuit fault and / or ground fault) from currents flowing through the switches SW11 and SW21, respectively; , The output of the accident zone determiner R1, the voltage at one end and the other end of the switch SW11, and the voltage at one end and the other end of the switch SW21 as inputs. A switch control device C1 for controlling the first and second switches SW11 and SW21 in accordance with the result of the judgment by the accident section determiner R1 and the presence or absence of a voltage applied from the main line side and the backup line side; SW11 and S A primary side is connected to a circuit connecting between W21 and a transformer TS1 is connected on the secondary side to the load of the customer 1.

The power receiving unit U1 is connected to the loop circuit with the first switch SW11 positioned on the main line F1 side and a series circuit of the switches SW11 and SW21 inserted in series with the loop circuit L. I have.

U2 is an intermediate power receiving unit, which is provided for the first and second switches SW12 and SW22 and the first and second switches SW12 and SW22 connected in series with each other. And first and second fault detectors D12 and D22 for detecting the presence or absence of a fault from the currents flowing through the switches SW12 and SW22, respectively.
The first and second switches SW12 according to the result of the judgment by the accident section determiner R2 and the presence or absence of the voltage applied from the main line side and the spare line side. A switch control device C2 for controlling the switch SW22;
A primary side is connected to a circuit connecting the switches SW12 and SW22, and a secondary side is configured by a transformer TS2 connected to a load of the customer 2.

This intermediate power receiving unit U2 has at least one
The first switch SW12 is provided on the main line F1 side, and is connected to the loop circuit with the series circuit of the switches SW12 and SW22 inserted in the loop circuit L in series.

U3 is a standby line side end power receiving unit, which is composed of a first and a second power receiving unit connected in series with each other.
Switches SW13 and SW23, and switches SW13 and SW23
Switches SW13 and SW23, respectively.
The first and second fault detectors D13 and D23 for detecting the presence or absence of a fault from the currents flowing through the respective sections, the fault section determiner R3 for determining fault sections, the fault results obtained by the fault section determiner R3 and the main line First and second switches SW13 according to the presence or absence of a voltage applied from the side and the spare line side.
Switch control device C3 for controlling the switch SW23 and the switch S
A primary side is connected to a circuit connecting between W13 and SW23, and a secondary side is constituted by a transformer TS3 connected to a load of a customer. This power receiving unit U3 is
The switch SW13 is connected to the loop circuit L with the switch SW13 and the switch SW23 connected in series with the loop circuit L in series.

The illustrated loop power distribution circuit is an open-loop power distribution circuit, in which the second switch SW23 of the standby line side power receiving unit U3 is kept open in a normal state (when there is no accident). All other switches SW11, SW21, SW12,
SW22 and SW13 are kept closed during normal operation.

The fault section determiner of each power receiving unit includes the outputs of the first and second fault detectors in each power receiving unit,
Of the first and second fault detectors in the adjacent power receiving unit, the output of the fault detector provided for the switch closer to each power receiving unit is input through a signal line s.

Further, in the illustrated example, the switch control device C1 of the main line side end power receiving unit U1 transmits the recovery of the voltage of the main line F1 to the backup line side end power receiving unit U3.
Switch control device C for power receiving unit U3
3 is connected through a signal line s', and when the voltage of the main line F1 recovers, the information is given from the control device C1 to the control device C3.

In this specification, among the first and second fault detectors in the power receiving unit adjacent to each power receiving unit, the fault detector provided for the switch closer to each power receiving unit is referred to as an adjacent fault detector. Call it a detector. That is, the power receiving unit U1
, The first accident detector D12 of the power receiving unit U2
Is an adjacent accident detector, and for the power receiving unit U2, the second accident detector D21 of the power receiving unit U1 and the first accident detector D13 of the power receiving unit U3 are adjacent accident detectors. For the power receiving unit U3, the second fault detector D22 of the power receiving unit U2 is an adjacent fault detector.

Each fault detector in each power receiving unit outputs a fault detection signal when a short-circuit fault or a ground fault fault is detected, and keeps the state of outputting the fault detection signal until reset. These fault detectors are composed of, for example, an overcurrent relay and a ground fault relay.

The fault section determiner in each power receiving unit determines from the input output of the fault detector whether or not the conditions 1 to 6 shown in FIG. 2 are satisfied. The accident section is determined, and the determination result is given to the switch control device. In FIG. 2, the determination result of the accident section when each condition is satisfied is shown in parentheses on the right column of each condition.

That is, the condition that both the first and second fault detectors in each power receiving unit have not detected a fault and the adjacent unit fault detector has not detected a fault is referred to as “condition 1”. When the condition 1 is satisfied, it is determined that no accident has occurred in each power receiving unit and the adjacent power receiving unit.

The condition that only one of the first and second accident detectors in each power receiving unit detects an accident is referred to as "condition 2". When the condition 2 is satisfied, each power receiving unit is detected. It is determined that the accident is within.

Further, a condition that both the first and second fault detectors in each power receiving unit detect a fault and there is an adjacent fault detector that does not detect a fault is defined as “condition 3｝”. Is established, it is determined that an accident has occurred in a circuit between adjacent power receiving units having adjacent accident detectors that have not detected an accident and each of the power receiving units.

The condition that both the first and second accident detectors in each power receiving unit detect an accident and the adjacent accident detector detects an accident is referred to as “condition 4”.
When the condition 4 is satisfied, it is determined that the accident is not an accident in each power receiving unit and an adjacent power receiving unit.

Furthermore, the first and the second in each power receiving unit
The condition that both of the accident detectors have not detected the accident and the adjacent accident detector has detected the accident is referred to as “condition 5”. When the condition 5 is satisfied, the accident is detected. It is determined that an adjacent accident detector is an accident between an adjacent power receiving unit and each power receiving unit.

After the power failure of the main line, the condition that the main line side of the backup line side end power receiving unit U3 is not charged even after the set time elapses is referred to as "condition 6". It is determined that the accident is an accident in the upper unit, an accident in the upper unit, or an accident between the upper units.

When an accident occurs (when a signal indicating the occurrence of an accident is input from the accident detector), the conditions 1 to 6 shown in FIG. 2 are satisfied by the accident section determiner in each power receiving unit. It is determined whether or not these conditions are satisfied, and when these conditions are satisfied, the determination result is given to the switch control device in the own power receiving unit.

The control device of each power receiving unit includes an output of an accident section determining device in each power receiving unit, a voltage on a main line side of a first switch of each power receiving unit, and a voltage on a backup line side of a second switch. Using the voltage as input, the first and second switches of each power receiving unit are controlled such that the fault section determined by the fault section determination device is separated from the healthy section and power transmission to the healthy section is allowed.

The switch control device of each power receiving unit has a computer, and controls a switch in its own power receiving unit by executing a predetermined program stored in its ROM. FIGS. 3 to 5 are flowcharts showing an example of a control algorithm of the control devices C1 to C3 of the power receiving units U1 to U3.

FIG. 3 shows a control algorithm of the switch control device C1 of the main line side end power receiving unit U1. The switch controller C1 receives the voltage of the terminal on the main line side of the first switch SW11 as an input and monitors whether there is a voltage on the main line as shown in step 1 of FIG.

When an accident occurs in the main line F1 or the loop power distribution circuit, a power substation (not shown) detects the accident, and a predetermined time period (for example, 6 to 7) after the accident occurs.
After the elapse of (seconds), the main circuit F1 is cut off because the circuit breaker of the power substation opens.

Switch control device C1 of power receiving unit U1
When the main line F1 is out of power, the first and second switches in each power receiving unit are first opened as shown in Step 2 of FIG. Thus, the first and second switches SW11 and SW21 in the own power receiving unit are controlled.

That is, when it is determined in step 3 that the condition 1 is satisfied (the first and second conditions in the power receiving unit U1).
Neither of the accident detectors of the above and the adjacent accident detector D12 of the adjacent unit U2 detect an accident, so an accident occurs in the power receiving unit U1 and between the adjacent power receiving unit U2 and the power receiving unit U1. If it is determined that the condition has not been satisfied), the process then proceeds to step 4 to determine whether or not the condition 6 is satisfied. If it is determined in step 4 that the condition 6 is satisfied (the unit U1 is not charged even if the set time period elapses after the power failure), the process proceeds to step 5 and the closing of the first switch SW11 is locked. 2 switches S
Insert W21. When it is determined in step 4 that the condition 6 is not satisfied (the set time has not yet elapsed after the power failure), the process proceeds to step 6 to check the charging of the main line side, and after the power receiving unit U1 in its own power receiving unit U1 has been confirmed. A process of turning on the first switch SW11 and the second switch SW21 is performed.

When it is determined in step 3 that condition 1 is not satisfied, it is determined in step 7 whether condition 2 is satisfied. As a result, when it is determined that condition 2 is satisfied ( Only one of the first and second accident detectors D11 and D21 in the power receiving unit U1 has detected an accident,
(When it is determined that the accident is within its own power receiving unit)
In step 8, the first switch SW11 and the second switch SW21 in the own power receiving unit U1 are locked from being turned on, and the first and second switches are checked even if charging on the main line side is confirmed. The switches SW11 and SW21 are not turned on.

If it is determined in step 7 that the condition 2 is not satisfied, the process proceeds to step 9 and the condition 3
Is determined whether or not Condition 3 is satisfied (when both the first and second accident detectors in each power receiving unit detect an accident and the adjacent power receiving unit U2 When the adjacent accident detector D12 does not detect an accident, it is determined that an accident has occurred in the circuit between the adjacent power receiving units U2 and U1 where the adjacent accident detector is located) Goes to step 10 and, among the first and second switches of the power receiving unit U1, an adjacent power receiving unit U having an adjacent accident detector that has not detected an accident
The closing of one switch SW21 on the side closer to 2 is locked, and the other switch SW11 is turned on after confirming charging on the main line side.

When it is determined in step 9 that the condition 3 is not satisfied, the process proceeds to step 11 to determine whether the condition 4 is satisfied. When it is determined that the condition 4 is satisfied, (Because both the first and second accident detectors D11 and D21 in the power receiving unit U1 have detected an accident, and the adjacent accident detector D12 in the power receiving unit U2 has detected an accident, the power receiving unit U1 When it is determined that the accident is not an accident in the power receiving unit U2 and the adjacent power receiving unit U2), the process proceeds to Step 12, and after confirming charging on the main line side, the first and second switches SW11 of the power receiving unit U1 are checked.
And SW21. When it is determined in step 11 that the condition 4 is not satisfied, the process returns to step 3.

FIG. 4 shows a control algorithm of the switch control device C2 of the intermediate power receiving unit U2. In this control device C2 also, in step 1, the mains side voltage (the mains terminal terminal of the switch SW12). Voltage) is monitored, and when the voltage on the main line runs out, the process proceeds to step 2 and the first
And open the second switches SW12 and SW22. Next, in Step 3, it is determined whether or not Condition 1 is satisfied.
When it is determined that the condition 1 is satisfied (within the power receiving unit U2 and between the adjacent power receiving units U1, U2 and U3, U2).
When it is determined that no accident has occurred between the two switches), the process proceeds to step 4, and after confirming charging, the switches SW12 and S
Insert W22.

When it is determined in step 3 that condition 1 is not satisfied, the process proceeds to step 5 to determine whether condition 2 is satisfied. When it is determined that condition 2 is satisfied (power reception) If it is determined that the accident is in the unit U2), then the routine proceeds to step 6, where the closing of the switches SW12 and SW22 in the power receiving unit U2 is locked.

When it is determined in step 5 that the condition 2 is not satisfied, it is determined in step 7 whether the condition 3 is satisfied. When it is determined that the condition 3 is satisfied (the power receiving unit U2 and the power receiving unit U2). If an accident has occurred in the circuit between the unit U3 and the unit U3), the operation proceeds to step 8 to lock the closing of the second switch SW22, and after charging is confirmed, the first switch SW12 is turned on. .

Further, when it is determined in step 7 that condition 3 is not satisfied, it is determined in step 9 whether condition 4 is satisfied. When it is determined that condition 4 is satisfied (power reception) If it is determined that there is no accident in the unit U2, between the adjacent power receiving unit U1 and the power receiving unit U2, and between the power receiving unit U2 and the power receiving unit U3), the process proceeds to step 10 to confirm charging. After that, the switches SW12 and SW22 are turned on.

Further, when it is determined in step 9 that the condition 4 is not satisfied, the condition 5 is determined in the step 11.
Is determined as to whether or not condition 5 is satisfied (accident detector D in power receiving unit U2).
21 and D22 did not detect the accident and power receiving unit U1
If it is determined that the fault is in the circuit between the power receiving unit U1 and the power receiving unit U2 because the fault detector D21 has detected the fault), the routine proceeds to step 12 and proceeds to the first step.
Is locked, and after confirming charging, the second switch SW22 is closed.

Next, FIG. 5 shows an auxiliary power line side end power receiving unit U3.
This figure shows a control algorithm of the switch control device C3 of FIG.
To monitor the presence or absence of the mains voltage (the voltage of the terminal on the power receiving unit U2 side of the first switch SW13), and when the mains fails, proceed to step 2 to open the first switch SW13. . Next, in step 3, when it is determined that the condition 1 is satisfied (when it is determined that no accident has occurred in the power receiving unit U3 and in the circuit between the power receiving unit U3 and the power receiving unit U2), step Proceeding to 4, it is determined whether or not condition 6 is satisfied. As a result, when the condition 6 is satisfied, the process proceeds to step 5 to check the charging of the spare line, and then turns on the first and second switches SW13 and SW23 in the own power receiving unit. If it is determined in step 4 that the condition 6 is not satisfied (the set time has not yet elapsed after the power failure), the process proceeds to step 6 to check the charging on the main line side, and then the power receiving unit U3 in its own power receiving unit U3 is checked. The process of turning on the first switch SW13 is performed.

If it is determined in step 3 that condition 1 is not satisfied, the process proceeds to step 7 to determine whether condition 2 is satisfied. If condition 2 is satisfied (in the power receiving unit U3) Accident is determined to be)
Proceeding to step 8, the first switch SW13 and the second switch
Of the switch SW23 is locked.

If it is determined in step 7 that the condition 2 is not satisfied, the process proceeds to step 9 to determine whether the condition 5 is satisfied. If the condition 5 is satisfied (the power receiving unit U3 and the If it is determined that there is an accident in the circuit between U2 and U2), the process proceeds to step 10 to lock the closing of the first switch SW13, and confirms the charging of the spare line. Input.

Although not shown in FIGS. 3 and 5, the switch SW23 of the power receiving unit U3 is turned on, and the power receiving unit U
When the main line F1 recovers while the switch SW11 of No. 1 is open and receiving power from the auxiliary line F2, the main line F1
The switch control device C1 of the power receiving unit U1 which detects the voltage of the power receiving unit U1 outputs a signal indicating that the voltage of the main line has been recovered through the communication line s' to the switch control device C3 of the power receiving unit U3.
Give to. At this time, the switch control device C3 sets the switch SW23.
Is opened, and the power receiving units U1 to U3 are temporarily stopped. In this state, the power receiving unit U1 and the power receiving unit U
If the condition 1 is satisfied in the power receiving unit U1 with no accident between the power supply unit 2 and the switch 2, the switch controller C1 checks the voltage of the main line F1 and turns on the switches SW11 and SW21. At this time, if condition 1 is satisfied in the power receiving units U2 and U3,
First, the switch control device C2 of the power receiving unit U2 is operated by the switch S.
W12 and SW22 are turned on, and then the switch control device C3 of the power receiving unit U3 turns on the switch SW13. As a result, a state in which power is received from the spare line is restored to a steady state in which charging is performed from the main line.

In the examples shown in FIGS. 3 to 5, the order in which the conditions 1 to 6 are determined is not limited to the illustrated example, and the order in which the conditions are satisfied is appropriately changed. Can be.

Next, assuming that an accident has occurred in each part of FIG. 1, the control operation of the switch will be specifically described. First, it is assumed that an accident occurs on the main line F1 of the distribution system and a power supply substation is out of power. In this case, since the control devices C1 to C3 of the power receiving units U1 to U3 detect the power failure, the first and second switches of the power receiving units U1 to U3 are opened. When an accident occurs on the main line, the fault detectors D11 and D21 in the power receiving unit U1 have not detected the fault, and the fault detector D12 of the adjacent power receiving unit U2 has not detected the fault. Condition 1 for U1
Holds. At this time, the accident section determiner R1 determines that no accident has occurred in its own power receiving unit and between its own power receiving unit U1 and the adjacent power receiving unit U2, and the switch controller C1 performs charging of the main line. After confirmation, the switches SW11 and SW21 are turned on.

At this time, the condition 1 is applied to the power receiving unit U2.
Holds, and the accident section determiner R2 is connected to its own power receiving unit, its own power receiving unit U2, and the adjacent power receiving unit U.
1 and the circuit between the own power receiving unit U2 and the adjacent power receiving unit U3, it is determined that no accident has occurred.
When the switches SW11 and SW21 of No. 1 are turned on, the switch SW12 is opened.
After confirming that the power receiving unit U1 has been charged on the main line side, the switches SW12 and SW22 are turned on.

Similarly, the condition 1 is also satisfied in the power receiving unit U3, and the fault section determiner R3 determines that no fault has occurred in the power receiving unit U3 and between the power receiving unit U3 and the adjacent power receiving unit U2. The switch controller C3 checks the charging of the main line side of the power receiving unit U3 by turning on the switches SW12 and SW22 of the power receiving unit U2, and then switches the switch S
Insert W13.

If an accident on the main line does not recover after a predetermined time limit after an accident occurs on the main line and a power failure occurs, condition 6 is satisfied in the power receiving unit U3. Check that the switches are charged and switch SW23 and SW13
Input. When the switches SW23 and SW13 are turned on, the switch control device C2 of the power receiving unit U2 checks the charging on the spare line side and then turns on the switches SW22 and SW12. When the switches SW22 and SW12 are turned on, the switch control device C1 of the power receiving unit U1 confirms the charging on the spare line side, locks the turning on of the switch SW11, and turns on the switch SW21.
Thus, the power receiving units U1 to U3 are in a state of receiving power from the spare line F2, and power is supplied to the customers 1 to 3.

When the main line F1 recovers in this state,
The switch control device C1 of the power receiving unit U1, which detects the voltage of the main line F1, supplies a signal indicating that the voltage of the main line has recovered to the switch control device C3 of the power receiving unit U3 through the communication line s'. Switch control device C1 is switch S
After inputting W11, the switch control device C3 sets the switch SW23.
open. As a result, the battery returns to a steady state in which charging is performed from the main line F1.

Next, in FIG. 1, a in the power receiving unit U 1
Suppose a short circuit accident occurs at a point. At this time, the power substation detects the accident, the circuit breaker of the substation opens, and the main line F1 is cut off. At this time, in the power receiving unit U1, since only the accident detector D11 has detected an accident, the condition 2 is satisfied in the power receiving unit U1. Therefore, the accident section determiner R1
Judge that an accident has occurred in its own power receiving unit,
The switch control device C1 locks the closing of switches SW11 and SW21.

In the power receiving unit U2, an accident detector D
Since the accidents 12 and D22 did not detect the accident, and the adjacent accident detectors D21 and D13 did not detect the accident, the condition 1 was satisfied. It is determined that no accident has occurred in the circuit between the power receiving unit and the adjacent power receiving unit.) However, since the switch SW21 of the power receiving unit U1 is not turned on, even if the voltage of the main line is restored, the power receiving unit U2 The switch control device C2 cannot confirm charging on the main line side. Therefore, even if the mains voltage recovers, the switch control device C2 can operate the switch SW12.
And SW22 are not turned on.

At this time, the condition 1 is satisfied also in the power receiving unit U3, and the accident section determiner R3 determines whether the accidental section determination unit R3 has its own power receiving unit U3 and the adjacent power receiving unit U2.
It is determined that no accident has occurred in the circuit between and.
If the switches SW12 and SW22 of the power receiving unit U2 are not turned on, the voltage of the main line is not applied to the power receiving unit U3, so that the condition 6 is satisfied when a set time period elapses after the power failure of the main line. Therefore, after the switch controller C3 confirms that the spare line F2 has been charged, the switches SW23 and SW13 are turned on to apply the voltage of the spare line to the power receiving unit U2.
At this time, since the condition 1 is satisfied in the power receiving unit U2, the switch controller C2 turns on the switches SW12 and SW22 after confirming the charging on the spare line side.

Next, in FIG. 1, a case where an accident occurs at point b of the circuit between the power receiving unit U1 and the power receiving unit U2 will be considered. When an accident occurs at point b, the power substation detects this, so the circuit breaker of the power substation opens and the main line F
1 loses power. As a result, the power receiving units U1 to U3
All switches are open. At this time, both of the fault detectors D11 and D21 of the power receiving unit U1 have detected a fault, but the fault detector D of the adjacent power receiving unit U2 has been detected.
12 and D22 did not detect an accident. Similarly, the fault detectors D13 and D23 of the power receiving unit U3 do not detect any fault.

At this time, since the condition 3 is satisfied in the power receiving unit U1, the accident section determiner R1 determines that an accident has occurred between the power receiving units U1 and U2, and the switch controller C1 operates the switchgear C1. After locking the switch SW21 and confirming the charging on the main line side, the switch SW11 is closed. Further, since the condition 1 is satisfied in the power receiving unit U3, the accident section determiner R3 determines that no accident has occurred in the own power receiving unit and in the circuit between the own power receiving unit and the adjacent power receiving unit U2. However, since the switch SW21 remains open, the switch control device C3 cannot turn on the switch SW13 even when the mains voltage is restored. When a predetermined time period has elapsed after the mains voltage is no longer applied to the power receiving unit U3, the condition 6 is satisfied in the power receiving unit U3, and the switch controller C3 confirms the charging of the spare line, and checks the switches SW23 and SW13. Input.

At this time, in the power receiving unit U2, the condition 5 is satisfied, and the accident section determiner R2 sets the power receiving unit U2
In order to determine that an accident has occurred between U1 and U1, the switch control device C2 locks the switch SW12 to be closed, turns on the switch SW22 after confirming that the spare line has been charged. As a result, the power receiving units U2 and U3 enter a state of receiving power from the spare line, and power is supplied to the customers 1, 2, and 3.

Next, consider a case where an accident occurs at point c in the power receiving unit U2 of FIG. When an accident occurs at the point c, the power substation detects this and opens the circuit breaker to shut down the main line F1. As a result, all the switches of the power receiving units U1 to U3 are opened. When an accident occurs at the point c, the condition 4 is satisfied in the power receiving unit U1, and therefore, the fault section determiner R1 determines that the fault is not an accident in the power receiving unit U1 or between the power receiving units U1 and U2. are doing. Therefore, after confirming that the main line F1 has been charged, the switch controller C1 turns on the switches SW11 and SW21. In the power receiving unit U2, since the condition 2 is satisfied,
The accident section determiner R2 determines that the accident is within the power receiving unit U2. Accordingly, the switch control device C2 locks the switches SW12 and SW22 of the power receiving unit U2 from being turned on. Since the power receiving unit U3 is not charged from the main line side even if a predetermined time period has elapsed after the main line power failure, the condition 6
Holds. In the power receiving unit U3, the condition 1 is satisfied, and the fault section determiner R3 determines that the fault is not an error in the power receiving unit U3 or between the power receiving units U3 and U2. When the condition is satisfied, the switches SW13 and SW23 are turned on. As a result, power is transmitted to the power receiving unit U1 from the main line, and the power receiving unit U3 is transmitted.
Then, power is transmitted from the spare line. When the accident at the accident point c is restored, the switch S of the power receiving unit U2
W12 and SW22 are turned on, and a command is artificially given to the switch control device of the power receiving unit U3 to open the switch SW23.
This returns to the steady state of charging from the main line.

Although not shown in FIG. 1, the power receiving unit U
In order to inform the power receiving unit U3 of the restoration of the accident within 2,
It is preferable that the switch control device C2 of the power receiving unit U2 and the switch control device C3 of the power receiving unit U3 are also connected by a communication line.

In the example shown in FIG. 1, the intermediate power receiving unit U
2 is provided, but the number of intermediate power receiving units is 2.
It is needless to say that the present invention can be similarly applied to a case where a plurality of units are provided. In that case, the recovery of the accident in the intermediate power receiving unit is
It is preferable to connect the switch control device in each intermediate power receiving unit to the switch control device of the auxiliary power receiving unit U3 through a communication line.

The present invention can also be applied to a case where only the main line side end power receiving unit U1 and the spare line side end power receiving unit U3 are installed except for the intermediate power receiving unit U2 from the example shown in FIG. . In this case, the configurations of the power receiving units U1 and U3 are the same as those shown in FIG. 1, and the control algorithms of the control devices C1 and C2 may be the same as those shown in FIGS.

[0082]

As described above, according to the loop power distribution circuit according to the present invention, each of the power receiving units is provided with the faulty section determining device and the switch control device, and according to the determination result by the faulty section determining device, Since the accident section is separated from the healthy section, and the first and second switches of each power receiving unit are controlled so as to allow the restart of power transmission to the healthy section, the switch is accurately provided for each power receiving unit. By controlling, it is possible to perform separation of the accident section and retransmission to the healthy section. Therefore, there is no need to connect the power company's business office and each power receiving unit with a communication line, so that the cost required for the equipment can be reduced.

According to the accident section determination method according to the present invention, each power receiving unit determines an accident section without collecting accident information in a large number of power receiving units arranged in a loop circuit in a master station. Therefore, the switch of each power receiving unit can be accurately controlled using the determination result.

Further, according to the switch control method according to the present invention, when an accident occurs, each power receiving unit can control the switch in the self-power receiving unit so that the fault section can be separated from the healthy section, and the voltage of the main line can be reduced. Upon recovery, power can be supplied from the main line to a healthy section. If an accident occurs in or between units in the middle of the loop distribution circuit and there is a healthy section where power cannot be supplied from the main line, power can be supplied to the healthy section from the backup line. Therefore, without connecting the master station and each power receiving unit by a communication line, each switch of the power distribution circuit can be accurately controlled, and the reliability of power supply can be secured.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a configuration example of a power distribution circuit according to the present invention.

FIG. 2 is a table collectively showing judgment conditions in the accident section judgment method according to the present invention.

FIG. 3 is a flowchart illustrating an example of a control algorithm of a switch control device of the power receiving unit U1 of FIG. 1;

FIG. 4 is a flowchart showing an example of a control algorithm of a switch control device of the power receiving unit U2 of FIG. 1;

FIG. 5 is a flowchart illustrating an example of a control algorithm of a switch control device of the power receiving unit U3 of FIG. 1;

[Explanation of symbols]

F1 ... main line, F2 ... spare line, L ... loop circuit, U1 ... main line side end power receiving unit, U2 ... intermediate power receiving unit, U3
... Reception line side end power receiving unit, SW11, SW12, SW13
... first switch, SW21, SW22, SW23 ... second switch, D11, D12, D13 ... first accident detector, D21, D2
2, D23: second fault detector, R1 to R3: fault section determiner, C1 to C3: switch control device, TS1 to TS3: transformer.

Claims (4)

[Claims] A primary side is connected to a first and a second switch connected in series to each other and a circuit connecting the first and the second switch, and a secondary side is connected to a load of a customer. First and second fault detectors provided for the connected transformer and the first and second switches, respectively, for detecting faults from currents flowing through the first and second switches, respectively. And a plurality of power receiving units each including a power receiving unit provided in the middle of a loop circuit provided between the main line and the backup line of the power distribution system.
The first switch is inserted in series with the loop circuit with the first switch positioned on the main line side, and the second switch of the power receiving unit disposed closest to the backup line is in a normal state. In a loop power distribution circuit in which an open state is maintained and all other switches are normally closed in a steady state, each of the power receiving units includes an output of the first and second accident detectors in its own power receiving unit. And an accident section determiner that determines an accident section by using an output of an accident detector provided for a switch in an adjacent power receiving unit as an input, and an accident section determined by the accident section determiner as a sound section. Disconnect from
A loop power distribution circuit comprising: a switch control device that controls first and second switches in its own power receiving unit so as to allow power transmission to a healthy section to be restarted. 2. A primary side is connected to a first and second switch connected in series to each other and a circuit connecting the first and second switches, and a secondary side is connected to a load of a customer. First and second fault detectors provided for the connected transformer and the first and second switches, respectively, for detecting faults from currents flowing through the first and second switches, respectively. And a plurality of power receiving units each including a power receiving unit provided in the middle of a loop circuit provided between the main line and the backup line of the power distribution system.
The first switch is inserted in series with the loop circuit with the first switch positioned on the main line side, and the second switch of the power receiving unit disposed closest to the backup line is in a normal state. An accident section determination method for determining an accident section in each power receiving unit when an accident occurs in the loop power distribution circuit, wherein the power switch is held in an open state and all other switches are kept closed in a steady state. In the power receiving unit located next to
And an accident detector provided for a switch closer to each power receiving unit among the second accident detectors as an adjacent accident detector for judging an accident section, and outputting an output of the adjacent accident detector through a communication line. Each power receiving unit is taken in by each power receiving unit, when both the first and second accident detectors in each power receiving unit have not detected an accident and the adjacent unit accident detector has not detected an accident. It is determined that no accident has occurred within and within the adjacent power receiving unit, and when only one of the first and second accident detectors in each power receiving unit has detected an accident, It is determined that the accident is not detected when both the first and second accident detectors in each power receiving unit detect an accident and there is an adjacent accident detector that does not detect the accident. Next to the adjacent accident detector It is determined that an accident has occurred in the circuit between the power receiving unit and each power receiving unit, both the first and second fault detectors in each power receiving unit detect the fault, and the adjacent fault detector When an accident is detected, it is determined that the accident is not an accident in each power receiving unit or in the adjacent power receiving unit, and both the first and second accident detectors in each power receiving unit have detected the accident. And when the adjacent accident detector is detecting an accident, it is determined that the adjacent accident detector detecting the accident is an accident between the adjacent power receiving units and each of the power receiving units. A method for determining an accident section of a loop distribution circuit. 3. A primary side is connected to a first and a second switch connected in series to each other and a circuit connecting the first and the second switch, and a secondary side is connected to a load of a customer. First and second fault detectors provided for the connected transformer and the first and second switches, respectively, for detecting faults from currents flowing through the first and second switches, respectively. At least three power receiving units having the following configuration are installed in the middle of a loop circuit provided so as to connect between the main line and the backup line of the power distribution system.
And a second switch of the power receiving unit, which is inserted in series with the loop circuit with the first switch positioned on the main line side, and is disposed at a position closest to the spare line. Is held open during normal operation, and all other switches are kept closed during normal operation.When an accident occurs in the loop power distribution circuit, each power receiving unit determines the fault section, and according to the determination result, A switch control method of a loop power distribution circuit for controlling first and second switches of each power receiving unit, wherein the first and second accident detectors in adjacent power receiving units disposed adjacent to each power receiving unit Of the accident detector provided for the switch closer to each power receiving unit as an adjacent accident detector for determining an accident section, the output of the adjacent accident detector is taken into each power receiving unit through a communication line, Closest to main line In the main line side end power receiving unit arranged at the position, both the process of opening the first and second switches when the main line fails, and the first and second accident detectors in its own power receiving unit Neither of the adjacent power receiving unit and the adjacent accident detector in the adjacent power receiving unit have detected an accident, and when it is confirmed that the main line has been charged within a set time after the main line power failure, the power receiving unit of its own The first and second switches are turned on, and the first and second switches in the own power receiving unit are turned on.
Neither of the accident detectors nor the adjacent accident detector in the adjacent power receiving unit has detected an accident, and charging of the main line is not performed even if a set time has elapsed after the main line was cut out. When the confirmation cannot be made, the closing of the first switch of the own power receiving unit is locked, but the second switch is turned on after confirming the charging of the preselection side, and the first and second switches of the own power receiving unit are locked. Locking the first and second switches of the own power receiving unit when only one of the fault detectors detects the fault, and the first and second faults in the own power receiving unit When both of the detectors detect an accident, and the adjacent accident detector in the adjacent power receiving unit does not detect an accident, the second switch of the own power receiving unit is locked, but the first switch is closed. The instrument is turned on when the mains voltage is restored. The mains voltage is restored when both the first and second fault detectors in the own power receiving unit and the adjacent fault detector in the adjacent power receiving unit detect a fault. And turning on the first and second switches of the own power receiving unit, and at the auxiliary line side end power receiving unit arranged closest to the auxiliary line, the main line has a power failure. Sometimes the process of opening the first switch and the first and second switches in the own power receiving unit.
Neither of the accident detectors nor the adjacent accident detector in the adjacent power receiving unit has detected an accident, and when it is confirmed that the main line has been charged within a set time after the main line power failure. The first switch in the own power receiving unit is turned on, and both the first and second accident detectors in the own power receiving unit and the adjacent accident detector in the adjacent power receiving unit detect an accident. If the charging of the main line cannot be confirmed even after a set time has elapsed after the power failure of the main line, the first and second opening / closing of the own power receiving unit after confirming the charging of the spare line The process of putting the container,
Locking only the closing of the first and second switches of the own power receiving unit when only one of the first and second accident detectors of the own power receiving unit detects an accident; When both the first and second accident detectors in the power receiving unit have not detected an accident, and the adjacent accident detector in the adjacent power receiving unit has detected an accident, the first and second accident detectors in the own power receiving unit have been detected. The first switch is locked, but the second switch is turned on after confirming charging on the spare line side, and the second switch is connected to the main line end power receiving unit and the spare line side end power receiving unit. In the intermediate power receiving unit disposed therebetween, the process of opening the first and second switches in the event of a power failure, the first and second accident detectors in the own power receiving unit, and the adjacent power receiving units on both sides. Neither of the adjacent accident detectors When the charging is confirmed, the first and second switches of the own power receiving unit are turned on after confirming the charging, and only one of the first and second fault detectors of the own power receiving unit detects the fault. When the first of its own power receiving unit
Locking the closing of the second switch and the second switch, and detecting both the first and second fault detectors in the own power receiving unit and detecting the fault in the adjacent power receiving unit disposed on the spare line side. When the adjacent accident detector has not detected an accident, the closing of the second switch of the own power receiving unit is locked,
The first switch is turned on after confirming charging, and the first switch is connected to both the first and second fault detectors in its own power receiving unit and adjacent fault detectors in adjacent power receiving units disposed on both sides. A process of turning on the first and second switches of the own power receiving unit after confirming charging when any of them detects an accident, and a first and second accident detector in the own power receiving unit Are not detecting an accident, and when the adjacent accident detector of the adjacent power receiving unit arranged on the main line side detects the accident, the first switch in the own power receiving unit is turned on. Locking the second switch, and then turning on the second switch after confirming the charging, wherein the switch is controlled by the loop power distribution circuit. 4. A primary side is connected to a first and a second switch connected in series to each other and a circuit connecting the first and second switches, and a secondary side is connected to a load of a customer. First and second fault detectors provided for the connected transformer and the first and second switches, respectively, for detecting faults from currents flowing through the first and second switches, respectively. Are installed in the middle of the loop circuit provided so as to connect the main line and the backup line of the power distribution system, and the first and second switches of each of the power receiving units are provided with the first and second switches. The switch of the power receiving unit, which is inserted in series with the loop electric circuit with the switch of the power line located on the main line side, and which is arranged at a position close to the spare line, is held in an open state at a normal time, All other switches are closed during normal operation A method for controlling a switch in a loop power distribution circuit, wherein each power receiving unit determines an accident section when a fault occurs in the loop power distribution circuit, and controls the first and second switches of each power receiving unit according to the determination result. A fault detector provided for a switch closer to each power receiving unit among the first and second fault detectors in the adjacent power receiving unit disposed next to each power receiving unit is used for determining an accident section. As an adjacent accident detector, the output of the adjacent accident detector is taken into each power receiving unit through a communication line, and at a main line side end power receiving unit arranged near the main line, the first and the second when a power failure occurs in the main line. The step of opening the second switch, neither the first nor the second accident detector in the own power receiving unit nor the adjacent accident detector in the adjacent power receiving unit has detected an accident, And the main line When charging on the main line side is confirmed within a set time after the power failure, the first and second switches of the own power receiving unit are turned on, and the first and second accident detectors in the own power receiving unit are turned on. Neither of them nor the adjacent accident detector in the adjacent power receiving unit has detected an accident, and if charging of the main line cannot be confirmed even after a lapse of a set time after the main line power failure, its own Locking of the first switch of the power receiving unit is locked, but the second switch is turned on after confirming the charging of the preliminary selection side, and the first switch and the second accident detector of the own power receiving unit are locked. Locking only the first and second switches of the own power receiving unit when only one of them detects an accident;
And both the second fault detector and the second fault detector detect the fault, and when the adjacent fault detector in the adjacent power receiving unit does not detect the fault, the second switch of the own power receiving unit is locked. The first switch is turned on after confirming the voltage on the main line side, and either the first and second fault detectors in the own power receiving unit or the adjacent fault detector in the adjacent power receiving unit are used. And then turning on the first and second switches of the own power receiving unit after confirming charging on the main line side while detecting an accident, and performing a backup operation at a position close to the backup line. In the power receiving unit on the line side, the process of opening the first switch when the main line is interrupted, and the detection of both the first and second accident detectors in the own power receiving unit and the adjacent accident in the adjacent power receiving unit Neither of the devices detected the accident And, when charging of the main line side is confirmed within a set time after the main line power failure, the first switch in its own power receiving unit is turned on,
Neither the first nor the second fault detector in the own power receiving unit nor the adjacent fault detector in the adjacent power receiving unit has detected any fault, and the fault has been set after the main line has lost power. If charging of the main line cannot be confirmed even after a lapse of time, a step of turning on the first and second switches of the own power receiving unit after confirming the charging of the spare line, and first and second switches of the own power receiving unit. When only one of the second accident detectors detects an accident, the first of its own power receiving units
Locking the closing of the second switch and the second switch, and the first and second fault detectors in the own power receiving unit have not detected any fault, and the adjacent fault detector in the adjacent power receiving unit has been detected. Locks the turning on of the first switch in its own power receiving unit when detecting an accident, but turns on the second switch when it confirms charging on the spare line side. A method for controlling a switch of a loop power distribution circuit.