Power distribution network small current single-phase ground fault protection method, system, device and medium

Abstract

The present application relates to the technical field of relay protection, and provides a power distribution network small current single-phase ground fault protection method, system, device and medium, comprising: when a suspected ground fault is monitored, starting a preset protection action criterion according to fault transient data; in response to the starting of the preset protection action criterion, performing gradient current limiting and starting fault self-healing monitoring; after entering the current limiting steady state period, generating a detection signal and actively injecting it based on the current power distribution network operating parameters; performing fault analysis according to the detection signal response characteristics and the current power distribution network operating parameters; performing protection delay analysis according to the fault level, fault distance and protection device downstream load priority to obtain a protection action delay; when the preset self-healing monitoring time is exceeded and the fault is not self-healed, triggering a circuit breaker to perform a protection action according to the protection action delay. The present application can improve the scientific rationality of small current ground fault protection in scenarios such as new energy weak feeding and weak fault characteristics, and effectively balance protection speed and power supply reliability.

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