Method and equipment for recovering power supply of non-fault section at downstream of grounding fault

Abstract

The invention discloses a method and equipment for recovering power supply of a non-fault section at the downstream of a grounding fault. The method comprises the following steps of: configuring equipment; when a grounding fault occurs in a main line of a power distribution network, detecting the grounding fault through section switches, and judging a transient power direction while starting protection delay timing; driving the first section switch at the upstream of the fault point to delay T1 and then tripping, and delaying T2 and then reclosing; after the first section switch is coincided,if the fault disappears, directly recovering the power supply of a downstream non-fault section, otherwise, accelerating tripping to isolate the fault point; when each section switch at the downstreamof the grounding fault point loses power and then is powered on, accelerating tripping after a grounding fault is detected; when an interconnection switch detects single-side voltage loss, delaying T3, and turning on the interconnection switch; making each section switch sequentially delay T4 from the interconnection switch to the fault point direction so as to be switched on; and after the nearest section switch at the downstream of the fault point is switched on to the grounding fault, accelerating tripping, so that the fault point is isolated, and the downstream non-fault section recoverspower supply.

Description

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

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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