A method and device for restoring power supply to a non-faulty section downstream of a ground fault

Abstract

The invention discloses a method and equipment for restoring power supply in a non-faulty section downstream of a ground fault. The method includes the steps of: equipment configuration; when a ground fault occurs in a main line of a distribution network, a segment switch detects the ground fault and determines the direction of transient power; At the same time, start the protection delay timer; the first segment switch upstream of the drive fault point will trip after a delay of T1, and reclose after a delay of T2; after the first segment switch recloses, if the fault disappears, the downstream will be restored directly The non-fault section supplies power, otherwise it will accelerate the trip to isolate the fault point; when each sub-section switch downstream of the ground fault point loses power and then powers on, the ground fault is detected and the trip is accelerated; the tie switch detects the loss of voltage on one side, and the delay T3 is closed. The upper tie switch; each section switch is delayed by T4 from the tie switch to the fault point in turn to close; the nearest section switch downstream of the fault point is closed to the ground fault and then accelerated to trip, the fault point is isolated, and the downstream non-fault section is Restore power.

Description

technical field [0001] The invention relates to a method and equipment for restoring power supply in a non-faulty section downstream of a ground fault, and belongs to the technical field of relay protection of power system distribution network. Background technique [0002] In recent years, the small current grounding fault detection technology has made great progress. In 2017, the "Technical Guidelines for Distribution Networks" issued by the State Grid Corporation of China added a small current grounding system "permanent single-phase grounding fault line selection, nearby rapid isolation ” requirements, and put forward “refer to international advanced practices and change the long-standing traditional practice of continuous operation for 2 hours under single-phase-to-ground faults”. It is an important means to improve the safety of distribution network equipment and personnel and the reliability of power supply to realize the nearby rapid isolation of single-phase ground ...

AI Technical Summary

Problems solved by technology

[0004] However, for the non-faulted section downstream of the main line fault point, since the transient power direction of the contact switch is opposite to that of normal operation after the contact switch is closed, it is no longer possible to realize the ground fault through the original power direction configuration and action time limit configuration. Judgment to restore power

The use of the existing centralized feeder automation technology needs to rely on the cooperation of communication and distribution automation master stations. The use of local distribution automation technology requires the configuration of complete local distribution automation terminal functions, resulting in the design of transient direction protection switches and Complex configuration

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