A ground fault detection method for distributed power access to distribution network

Abstract

The invention discloses a grounding fault testing method for a distributed power supply integrated power distribution network. The method comprises the following steps mounting a protection proxy on each bus of the power distribution network which comprises distributed power supplies, and performing centralized management and control on a local protection device; when the zero-sequence voltage of the bus exceeds a limit, recording sampling data which are measured by the local protection device; calculating a relative distance between the sampling data and historical fault data, and furthermore determining a fault area; and finally determining a fault line through a communication network and cooperation among the protection proxies, and transmitting a trip-out signal. The method according to the invention is not affected by integration number, capacities and positions of the distributed power supplies, and furthermore has relatively high adaptability and relatively high reliability. Furthermore the method thoroughly settles problems of low grounding fault protection accuracy and low reliability after the distributed power supplies are integrated into the power distribution network.

Description

technical field [0001] The invention relates to a method for detecting a grounding fault of a distributed power supply connected to a distribution network, which is suitable for a distributed power supply connected to a distribution network. Background technique [0002] Since my country's power distribution system is widely used in the non-effective grounding mode, when a single-phase ground fault occurs in the distribution network, the fault characteristic quantity is not obvious, and it is difficult to reliably detect the fault line. In this regard, single-phase-to-ground fault detection in distribution network has always been a research hotspot at home and abroad. [0003] With the needs of my country's energy development strategy, distributed power sources with intermittent renewable energy such as wind and light as the core account for an increasing share in the distribution network, which will inevitably affect the single-phase ground fault of the traditional distribu...

AI Technical Summary

Problems solved by technology

However, these methods only deal with single fault characteristic quantities such as current or voltage, and the setting of the protection setting value is easily affected by the complex actual working conditions after the distributed power generation is connected to the grid, resulting in low protection reliability and even causing Malfunction or refusal to protect

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