JP2009055731A - Automatic power recovery system of spot network power receiving equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic power recovery system of spot network power receiving equipment which can prevent total power outage over a long period of time without deviating from the use conditions of the setting purpose of bus bar liaison breakers. <P>SOLUTION: When a bus bar earth fault protection breaker 18 detects an earth fault of a network bus bar 15, a control device 19 opens all protector breakers 14a, 14b, and 14c connected to the secondary side of a plurality of network transformers 13a, 13b, and 13c connected to a power receiving line to cause total power outage. Thereafter, the control device 19 opens the bus bar liaison breakers 16a and 16b and divides the network bus bar 15, and sequentially powers on the protector breakers 14a, 14b, and 14c until it can find a divided bus bar with no earth fault and automatically recovers power for the divided bus bar with no earth fault. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an automatic power recovery system for a spot network power receiving facility in which a spot network bus bar is provided with a bus line breaker.

  In general, a spot network power receiving facility receives power from a plurality of special high-voltage distribution lines via network transformers and interconnects the secondary sides of each network transformer in parallel. This is a highly reliable power distribution system that can receive power without any trouble even if one line of the wire stops. Network power receiving equipment is used for power distribution to specific high-load power consumers such as buildings and factories.

  For example, in a 22 kV spot network power receiving facility, as shown in FIG. 3, power is received by three 22 kV distribution lines 11a, 11b, and 11c, and each power receiving line includes disconnectors 12a, 12b, and 12c, and network transformer 13a. , 13b, 13c and protector circuit breakers 14a, 14b, 14c are connected to the network bus 15. A single bus is standard for the network bus 15 on the secondary side of the network transformers 13a, 13b, and 13c. Then, electric power is supplied from the network bus 15 to the load of each delivery feeder via the circuit breaker 17.

  The network bus 15 is provided with bus bar breakers 16a and 16b, and is divided into divided bus lines 15a and 15b by the bus bar breakers 16a and 16b. The purpose of installing the bus bar breakers 16a and 16b is to prevent a total power outage at the time of electrical equipment inspection. It is manually operated from the spot network protection system under the deenergization (no load condition) of the bus bar breaker. Opening and closing operations are performed. Also, a bus ground fault protection relay 18 for detecting the ground fault of the network bus 15 is provided. When a ground fault occurs in the network bus 15, the bus ground fault detection protection device 18 operates and the network transformers 13a, 13b, 13c are operated. All the secondary side circuit breakers 14a, 14b, 14c are opened. Therefore, when a ground fault occurs in the network bus 15, the customer side is completely out of power. In the spot network power receiving equipment, it is assumed that a ground fault does not occur in the network bus 15 due to the implementation of insulation reinforcement measures, or the possibility that it will occur is very low. In the event of a failure, all blackouts will occur.

Here, when there is a ground fault in the network bus, there is one that uses a bus breaker to open between the network buses to prevent a total power outage of the network receiving / transforming equipment due to simultaneous opening of the protector breaker (for example, , See Patent Document 1)
Japanese Patent No. 3480671

  However, in Patent Document 1, a ground fault protection relay is installed for each bus divided by the bus contact breaker, and when the bus ground fault is detected, the bus contact breaker is opened and the bus that has detected the ground fault is disconnected. After that, the protector breaker of the bus that caused the ground fault is opened, so it is possible to isolate the accident point in a short time without any power failure, but the busbar breaker with the bus in the energized state (load state) This is a departure from the intended use conditions of the busbar breaker.

  In other words, the bus bar breaker divides the network bus 15 at the time of electrical equipment inspection to prevent all power outages, and maintains the reliability of the spot network protection system by operating under the condition of de-energization. Yes. Therefore, the opening / closing operation in an energized (loaded) state is not preferable.

  On the other hand, if a ground fault occurs in the network bus and a total power failure occurs, for example, if the customer of the spot network power receiving facility is a heat supply (DHC) operator, it will not be possible to supply heat during the total power failure. . If there is a power outage associated with a power transmission accident at an electric power company, not only the heat supply operator but also the customer will be out of power, so it seems that it is possible to gain an understanding of stopping the heat supply. It is caused by an in-house accident, and it is difficult to obtain the customer's understanding that the supply of heat is stopped for a long time, and various problems are expected to occur.

  Here, the bus ground fault protection relay 18 operates not only when a ground fault occurs in the network bus 15 but also when the circuit breaker 17 is not opened when a ground fault occurs in the feeder feeder. There is. This is because the bus ground fault protection relay 18 also has a role of protecting the back-up when each feeder ground fault protection relay does not operate when a ground fault occurs in the feeder feeder. Therefore, even when each feeder ground fault protection relay is not operating, the bus ground fault protection relay 18 may operate and a total power failure may occur.

  An object of the present invention is to provide an automatic power recovery system for a spot network power receiving facility that can prevent a total power failure for a long time while maintaining the usage conditions for the purpose of installing a busbar breaker.

  An automatic power recovery system for a spot network power receiving facility according to the invention of claim 1 includes a plurality of protector breakers connected to a secondary side of a plurality of network transformers connected to a power receiving line, a plurality of network transformers, A bus contact breaker connected to a network bus to which power is supplied from the power receiving circuit via a plurality of protector breakers, a bus ground fault protection relay for detecting a ground fault of the network bus, and the bus ground fault protection And a control device that opens all the protector breakers when the relay is operated to make a total power failure, and the control device opens all the protector circuit breakers to make a total power failure, and then the bus line breaker Is opened, and the network bus is divided, and multiple protector circuit breakers are sequentially inserted one by one to automatically restore the divided buses where no ground fault has occurred. And wherein the Rukoto.

  An automatic power recovery system for a spot network power receiving facility according to a second aspect of the present invention is the automatic power recovery system for a spot network power receiving facility according to the first aspect, wherein the control device detects a ground fault again in the divided bus connected to the input protector breaker. Is characterized in that the protector breaker is opened again to make a closing lock, and when there are other uncovered protector breakers, the other protector breakers are sequentially turned on.

  According to the present invention, when the bus ground fault protection relay operates, all the circuit breakers are opened and all power failures occur, and then the bus bus circuit breaker is opened to divide the network bus. It is possible to maintain the usage conditions for the purpose of installing the busbar breaker that opens the network busbar. Then, after dividing the network bus, multiple protector breakers are sequentially turned on one by one to automatically restore the divided buses where no ground fault has occurred. Electricity is possible.

  Also, when a ground fault is detected again on the split bus connected to the supplied protector breaker, the protector breaker is opened again to make the lock, so that the split bus where the ground fault occurs is separated. it can. And when there is another protector breaker that has not been turned on, the other protector breakers are turned on sequentially, so that all the divided buses in which no ground fault has occurred can be restored.

  FIG. 1 is a configuration diagram of an automatic power recovery system for a spot network power receiving facility according to an embodiment of the present invention. Compared to the conventional example shown in FIG. 3, when the bus ground fault protection relay 18 is operated, all the protector circuit breakers 14a, 14b, 14c are opened to make all power failures, and then the bus line breakers 16a, 16b are opened. The network bus 15 is divided, and a plurality of protector circuit breakers 14a, 14b, 14c are sequentially turned on one by one to provide a control device 19 for automatically returning power to the divided buses in which no ground fault has occurred. The same elements as those in FIG. 3 are denoted by the same reference numerals, and redundant description is omitted.

  The bus ground fault protection relay 18 detects a ground fault of the network bus 15 and has a function of detecting a ground fault when the ground fault current is very small and a heavy ground fault with a ground fault current of a predetermined value or more. When a fine ground fault is detected, an alarm is output. When a heavy ground fault is detected, an alarm is output and the protector breakers 14a, 14b, and 14c are opened. Hereinafter, the case of a heavy ground fault is simply referred to as a ground fault.

  Further, the bus ground fault protection relay 18 operates not only when a ground fault occurs in the network bus 15 but also when the circuit breaker 17 is not opened when a ground fault occurs in the feeding feeder. It also serves as a backup protection when the relay is not operating.

  When the bus ground fault protection relay 18 operates by detecting a ground fault, the control device 19 opens each of the protector circuit breakers 14a, 14b, and 14c to make a complete power failure. Then, after elapse of a predetermined time period T1 after the protector circuit breakers 14a, 14b, and 14c are opened, the bus bar communication circuit breakers 16a and 16b are opened to divide the network bus line 15. Each of the protector circuit breakers 14a, 14b, 14c is opened, and the network bus 15 is in a non-energized state (no load state) after a predetermined time T1 has elapsed. In this state, the bus line breakers 16a, 16b are turned off. As a result, the bus bar breakers 16a and 16b are opened in a state where the network bus 15 should be opened and closed in a no-load state and satisfy the usage conditions for installation purposes.

  When the bus bar breakers 16a and 16b are opened, the network bus 15 is divided into split buses 15a and 15b. FIG. 1 shows a case where the network bus 15 is divided into two.

  In a state where the network bus 15 is divided by opening the bus bar breakers 16a and 16b, the control device 19 sequentially turns on the protector breakers 14a, 14b and 14c one by one. For example, the protector breaker 14a is turned on after a predetermined time period T2 elapses after the bus bar breakers 16a and 16b are opened. Thus, power is supplied to the divided bus 15a from the distribution line 11a via the network transformer 13a. When the ground fault has not occurred in the split bus 15a, the bus ground fault protection relay 18 does not operate, so that the power supply from the distribution line 11a is continued and the split bus 15a is restored. In this case, the next protector unit 14b is not inserted. This is because it is considered that a ground fault has occurred in the remaining split bus 15b since no ground fault has occurred in the split bus 15a.

  On the other hand, when the ground fault has occurred in the divided bus 15a, the bus ground fault protection relay 18 operates, so that the control device 19 opens the protector breaker 14a. In this case, since the protector circuit breaker 14a is interrupted again, the control device 19 locks the protector circuit breaker 14a and prevents the protector circuit breaker 14a from being turned on again.

  Next, the next protector breaker 14b is turned on after a predetermined time period T3 elapses after the first protector breaker 14a is turned on. As a result, power is supplied to the divided bus 15b from the distribution line 11b via the network transformer 13b. When there is no ground fault in the divided bus 15b, the divided bus 15b is restored. Note that it is virtually impossible that a ground fault has occurred in both of the divided buses 15a and 15b, but in the unlikely event that a ground fault has occurred in the split bus 15b, the bus ground fault protection relay 18 Therefore, the control device 19 opens the protector circuit breaker 14b, locks the protector circuit breaker 14b, and prevents the protector circuit breaker 14b from being turned on again.

  For the protector breaker 14c, when it is determined that the ground fault has not occurred in the split bus 15b by turning on the protector breaker 14b, the protector breaker 14c is turned on after a predetermined time period T4 after the protector breaker 14b is turned on. Power is supplied to 15b from the distribution line 11c via the network transformer 13c.

  In addition, when the ground fault has generate | occur | produced in the division | segmentation bus 15a by the insertion of the first protector circuit breaker 14a, you may make it insert the remaining protector circuit breakers 14b and 14c simultaneously. This is because a ground fault has occurred in the divided bus 15a, and it is considered that no ground fault has occurred in the remaining divided bus 15b.

  In the above description, the case where the network bus 15 is divided into two has been described, but it may be divided into three or more. In this case, the control device 19 sequentially turns on the plurality of protector breakers one by one, and stops the turn-on of other protector breakers at the time when the divided bus without a ground fault is restored. become.

  FIG. 2 is a flowchart showing the processing contents of the control device 19. The control device 19 constantly monitors whether or not the busbar protection ground fault relay 18 detects a ground fault (S1). When the busbar protection ground fault relay 18 detects a ground fault, all the protector circuit breakers 14a, 14b, 14c are opened (S2). As a result, the spot network power receiving facility is completely blacked out. After opening all the protector circuit breakers 14a, 14b and 14c, the bus bar connection circuit breakers 16a and 16b are opened after a predetermined time T1 (S3), and the network bus 15 is divided. The opening of the bus bar breakers 16a and 16b is performed in a state in which the network bus bar 15 is not loaded. Therefore, the operation is in accordance with the intended use conditions of the bus bar breakers 16a and 16b.

  Then, “1” is set to the variable i (S4), and the first protector breaker 14a is turned on after the predetermined time period T2 elapses after the bus bar breakers 16a and 16b are opened (S5). In this state, it is determined whether or not a ground fault has occurred in the divided bus 15a (S6). When a ground fault has occurred, the protector breaker 14a is opened and locked in so that it cannot be re-introduced (S7). .

  Next, it is determined whether or not the variable i is equal to n (the number of the protector breakers 14) (S8). That is, it is determined whether or not a closing operation has been performed on all the protector circuit breakers 14a, 14b, and 14c. On the other hand, when the ground fault does not occur in the determination of step S6, the process is terminated because the divided bus where the ground fault has not occurred has been restored.

  When it is determined in step S8 that i is not equal to n, that is, in a state where no divided bus with no ground fault has been found, all the protector breakers 14a, 14b, and 14c have been turned on. If not, add "1" to the variable i and return to step S5 (S9). Then, when a closing operation has been performed on all of the protector breakers 14a, 14b, and 14c in a state in which no divided bus without a ground fault is found, the process is terminated.

  As described above, in the embodiment of the present invention, at the time of a total power failure due to the operation of the protector circuit breakers 14a, 14b, 14c on the secondary side of the network transformers 13a, 13b, 13c due to the ground fault, the mother circuit breakers 16a, After the network bus 15 is divided by this, the protector breakers 14a, 14b, and 14c are forcibly sequentially inserted until a divided bus without a ground fault can be found. And when the division | segmentation bus 15 connected to the thrown protector circuit breaker 14 is healthy, it returns to electric power, and when there exists a ground fault, it interrupts | blocks again. Therefore, it is possible to restore the power of the healthy divided bus 15 in a short time.

  According to the embodiment of the present invention, when the bus ground fault protection relay 18 is operated, all of the protector circuit breakers 14a, 14b, 14c are opened to make all power outages, and then the bus bar communication circuit breakers 16a, 16b are opened. Then, since the network bus 15 is divided, it is possible to maintain the usage conditions for the purpose of installing the bus bar breakers 16a and 16b, in which the network bus 15 is opened in a no-load state. And after dividing | segmenting the network bus | bath 15, since several division | segmentation circuit breakers 14a, 14b, and 14c are thrown in one by one until the division | segmentation bus | bath which the ground fault does not generate | occur | produce can be found one by one, Early power recovery is possible.

  In addition, when a ground fault is detected again in the divided bus connected to the inserted protector circuit breakers 14a, 14b, 14c, the protector circuit breakers 14a, 14b, 14c are opened again to make a closing lock. It is possible to separate the divided buses where the tangling has occurred. As a result, it is possible to restore a healthy divided bus.

  Furthermore, for example, if the customer of the spot network power receiving equipment is a heat supply (DHC) operator, the heat supply will stop if the heat source devices are connected in a well-balanced manner to the feed feeder connected to the divided bus. There is a possibility of not having to.

The block diagram of the automatic power recovery system of the spot network power receiving equipment concerning embodiment of this invention. The flowchart which shows the processing content of the control apparatus in embodiment of this invention. The block diagram of the conventional spot network power receiving equipment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Distribution line, 12 ... Disconnector, 13 ... Network transformer, 14 ... Protector circuit breaker, 15 ... Network bus, 16 ... Busbar connection circuit breaker, 17 ... Circuit breaker, 18 ... Busbar ground fault protection relay, 19 ... Control apparatus

Claims (2)

A plurality of protector circuit breakers connected to the secondary side of a plurality of network transformers connected to the receiving line;
A bus contact breaker connected to a network bus to which power is supplied from the power receiving circuit via a plurality of network transformers and a plurality of protector breakers;
A bus ground fault protection relay for detecting a ground fault of the network bus;
A control device that opens all the protector breakers when the bus ground fault protection relay operates and makes a total power failure;
The control device opens all the protector breakers to make a complete power failure, then opens the bus bar breaker and divides the network bus, and sequentially puts a plurality of protector breakers one by one. An automatic power recovery system for a spot network power receiving facility, in which when a divided bus that does not generate power recovers, the protector circuit breaker is turned off and power is automatically recovered.   When a ground fault is detected again in the divided bus connected to the inserted protector circuit breaker, the control device opens the protector circuit breaker again to make a lock, and there are other protector circuit breakers that have not been turned on. 2. The automatic power recovery system for a spot network power receiving facility according to claim 1, wherein other protector circuit breakers are sequentially turned on to a bus line where no ground fault has occurred.

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