A Single-Phase Grounding Fault Handling Method Applicable to Small Current Grounding System

Abstract

Provided is a single-phase grounding fault handling method suitable for low-current grounding systems. The problem of coordination between outgoing line protection and line protection under a single-phase grounding fault in a low-current grounding system is solved. Low-current grounding fault protection methods by combining the load power direction and the grounding fault transient power directionwith the delays of terminals are provided respectively for radial lines and hand-in-hand lines, and local isolation of a low-current grounding fault is realized. All upstream healthy sections can remove faults without blackout. In a hand-in-hand network, downstream healthy lines can also be directly transferred to a standby power supply. The method of the invention can adapt to different modes ofdistribution network automation systems and distribution line protection devices, can be used to handle a low-current grounding fault quickly and accurately, and has wide practical application value.

Description

technical field [0001] The invention belongs to the field of relay protection for distribution networks, and in particular relates to a single-phase grounding fault processing method suitable for a small current grounding system. Background technique [0002] Small current ground fault location technology has become a research hotspot in recent years. Field applications include centralized feeder automation, and distribution terminals or fault indicators are often used to collect ground fault transient current waveforms. The centralized feeder automation method uses the principle of transient current similarity to locate the main station to determine the fault section. The positioning algorithm is relatively complicated, and it is difficult to cooperate with the terminals of different manufacturers and the main station. In distributed feeder automation, due to the more Less, algorithms based on transient current similarity are more difficult than centralized models. In add...

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Problems solved by technology

However, in the centralized feeder automation and distributed feeder automation modes, communication channels are required, which cannot adapt to distribution network protection systems that do not have communication conditions

[0005] In addition, at present, there are relatively mature configuration and setting schemes for short-circuit fault protection of distribution lines, but for small current ground faults, there is still a lack of protection schemes with perfect principles, reliable actions, and simple implementation

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