Acceleration method and relay protection device for distribution network fault removal

Abstract

The present invention relates to a power distribution network failure removal accelerating method and a relay protection device. Removal acceleration of two-phase short-circuit and two-phase short-circuit ground faults is realized through non-channel acceleration protection. Each circuit breaker is at least equipped with two sets of protection, i.e., a first set of protection and a second set of protection, and accelerated judgments of the first set of protection and the second set of protection are also configured. The two sets of protection set according to respective time setting rules, each set of protection also sets according to corresponding accelerated judgment, and accelerated judgment setting time is a delay [delta]t of side breaker action time. When failures occur, for any breaker, if action conditions and the accelerated judgment of one of the sets of protection are met, whether to act is determined according to the setting time. When two-phase short-circuit failures and two-phase short-circuit ground failures occur, isolation of fault regions may be accelerated. For feeder lines with more and more subsections, a protection acceleration effect becomes more and more obvious.

Description

technical field [0001] The invention relates to an acceleration method for fault removal of a distribution network, a relay protection method and a relay protection device, which are mainly applied to the relay protection of a distribution network whose neutral point is not effectively grounded. Background technique [0002] The 10kV distribution network generally adopts a common ring structure ( figure 1 As shown), closed-loop structure, open-loop operation, one circuit breaker in each feeder is installed with two sets of protection devices ( figure 2 Shown): over (current) current protection and low (electricity) voltage protection, the action time is set according to the step time, it is difficult to meet the requirements of high power supply reliability. Although there should be non-channel protection in the distribution network, which can improve the fault time and blackout area of ​​the distribution network, and achieve good results; but the current non-channel prote...

AI Technical Summary

Problems solved by technology

However, the existing non-channel protection has no effect on single-phase fault line selection

[0006] Compared with other faults, three-phase short-circuit faults are more harmful to the system. The closer to the power supply, the greater the fault current. The existing non-channel protection cannot accelerate the action, and can only rely on the traditional definite time limit over-current protection action.

However, overcurrent protection configuration: the closer to the power supply, the longer the protection delay time, and the further increase the damage to the power supply, so it is particularly important for the accelerated removal of three-phase symmetrical faults

[0007] Acceleration criterion for asymmetric fault protection without channel protection for effectively grounded systems is not applicable to non-effectively grounded distribution network systems

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