Differential protection method applicable to power distribution network

Abstract

The invention discloses a differential protection method applicable to a power distribution network. The differential protection method comprises the following steps of: (1) connecting each feeder circuit-breaker provided with differential protection with two or more switching nodes; (2) setting a failure state quantity Sn reflecting overcurrent information for each switching node; and (3) selecting that whether a power directional element is additionally arranged or not according to the failure state quantity Sn obtained by the step (2). According to the differential protection method, an Ethernet network or an EPON (Ethernet Passive Optical Network) communication system are supported, failure state quantity information is transmitted through GOOSE (Generic Object Oriented Substation Event), a protective range and logic can be configured on spot, and the problems that the existing power distribution network consumes long time for protection failure removal and power restoration, and has poor protection sensitivity and difficulty in interaction of protection, and the like are effectively solved.

Description

technical field [0001] The invention relates to a differential protection method suitable for distribution networks, which belongs to the field of relay protection automation in the field of electric power engineering. Background technique [0002] Considering the reasons of economy and technology, the circuit in my country's power distribution system mainly adopts quick-break and overcurrent protection, and the transformer mainly adopts fuse protection. The problems of this protection configuration are as follows: (1) The premise of current protection to realize distribution network protection is to regard the whole feeder as a unit. When the feeder fails, the entire line is cut off, and the restoration of power supply to the non-faulty area is not considered. This is very detrimental to ensuring the reliability of power supply. (2) Relying on the time difference to realize the selectivity of protection will cause the fault removal time to be too long, which will affect t...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a differential protection method suitable for distribution networks, which supports Ethernet or EPON communication systems, and uses GOOSE to transmit fault state information, and the protection range and logic can be configured on site, which effectively solves the problem of current power distribution problems. Network protection fault removal and power supply recovery time is long, protection sensitivity is poor, and protection is difficult to cooperate with each other, etc.

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