Method for single-phase ground fault isolation of distribution network line of arc suppression coil grounding system

Abstract

An embodiment of the invention discloses a method for single-phase ground fault isolation of a distribution network line of an arc suppression coil grounding system and aims to solve the technical problem of failure in correct judgment of single-phase ground faults due to zero sequence current protection caused by zero sequence currents in faulty lines and non-faulty lines and low ground fault current in occurrence of single-phase ground faults of medium voltage systems with neutral points grounded through arc suppression coils. The method includes: when the system is in the single-phase ground fault and a grounding line of a substation trips, section switches at all stages are disconnected to segment the faulty lines; after reclosing action of the substation, the section switches on the lines are switched on automatically step by step; when reclosing is performed at the position of the single-phase ground fault, a controller starts a zero sequence overvoltage post-acceleration protection function, and accordingly accuracy in fault elimination is achieved, harms to power equipment and human bodies are reduced, and safety and reliability in power grid operation are guaranteed.

Description

technical field [0001] The invention relates to the field of distribution networks, in particular to a method for isolating a single-phase grounding fault of a distribution network line in an arc suppressing coil grounding system. Background technique [0002] Distribution network automation terminal equipment is widely used in the market, including feeder automation terminal (FTU), distribution network automation measurement and control terminal (DTU), boundary switch controller, microcomputer relay protection device, cable fault indicator and other equipment. The rapid isolation of distribution network faults, the prevention of accident expansion, the improvement of power supply reliability, and the safe and stable operation of the power grid have played a key role. [0003] Single-phase ground faults account for a relatively large proportion of distribution network faults, and the above-mentioned distribution network automation terminal equipment uses special zero-sequenc...

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Problems solved by technology

[0005] The embodiment of the present invention provides a single-phase ground fault isolation method for the distribution network line of the arc suppression coil grounding system. Due to the inductance characteristics of the arc suppression coil, the ground fault current is very small, and both the fault line and the non-fault line will have zero-sequence current, resulting in the technical problem that the zero-sequence current protection cannot correctly judge the single-phase ground fault

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