Circuit breaker dead zone protection method

Abstract

The invention discloses a circuit breaker dead zone protection method, which relates to the field of power system relay protection, and comprises the following steps: setting a dead zone over-current protection constant value and time limit of a protection device BH-DL, and comparing the current of a current transformer corresponding to a circuit breaker with the dead zone over-current protection constant value when the circuit breaker is judged to be in an open position; when the current exceeds a dead-zone overcurrent protection constant value and meets a dead-zone overcurrent protection time limit, judging that a dead zone has a fault, and instantaneously cutting off an incoming circuit breaker on the power supply side of the dead zone; compared with an existing dead-zone protection method, the method has the advantages that the method does not need to add primary equipment such as an electronic transformer, does not depend on triggering of conventional current protection (quick-break protection, overcurrent protection and zero-sequence protection), does not need to collect bus voltage, adopts an existing protection device, and can quickly cut off the fault when the circuit breaker has the dead-zone fault.

Description

technical field [0001] This patent belongs to the field of relay protection for electric power systems, and specifically relates to a protection method for a dead zone of a circuit breaker. Background technique [0002] When the circuit breaker DL-BH is closed, the current protection corresponding to the protection device BH-DL and the current protection corresponding to other circuit breakers are the upper-lower coordination relationship, and the current setting value and time limit are set according to the standard difference. Since the circuit breaker DL-BH is usually not located at the end of the power supply network, in order to avoid tripping over the fault of the lower line, the current protection has a relatively high setting value and a relatively long time limit. [0003] But when the circuit breaker DL-BH is disconnected, a fault occurs in the dead zone. Since the fault is on the power side of the circuit breaker DL-BH, the circuit breaker DL-BH cannot remove the ...

AI Technical Summary

Problems solved by technology

[0003] But when the circuit breaker DL-BH is disconnected, a fault occurs in the dead zone. Since the fault is on the power side of the circuit breaker DL-BH, the circuit breaker DL-BH cannot remove the fault, and the circuit breaker DL-BH is already in the off state. In the open state, it can only be connected to the jumper circuit breaker DL-JX

Since the current protection setting value of the existing protection device BH-DL still adopts the setting of the current setting value and time limit according to the closing situation of the circuit breaker DL-BH, when the dead zone fault occurs, the protection device BH-DL cannot act instantaneously; if the fault is slight , then the fixed value of the current protection of the protection device BH-DL cannot be reached, resulting in a delayed action of the protection device BH-DL

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