A Reverse Power Protection Method for Point Networks Containing DERS Comparing the Direction of Positive Sequence Current

Abstract

The invention discloses a distributed energy resources-containing dotted network reverse power protection method comparing positive sequence current direction. According to the method, faults and power reversal caused by DERs output waveform are distinguished by using current break variable in ms level, so as to serve as a standard determining system running state, and a protective element is started; a fault position is recognized by using positive sequence current direction, a circuit breaker can be cut off rapidly when a fault occurs in upstream of a protection part, so as to isolate the fault. The method allows the system to have reverse power in normal running, effectively improves reverse power protection performance and increases access capacity of DERs remarkably.

Description

technical field [0001] The invention relates to the field of relay protection for point-like networks containing distributed power sources, in particular to a method for reverse power protection. Background technique [0002] As a special low-voltage power distribution structure, the low-voltage multi-source point network can effectively solve the problem of continuous and short-term power outages caused by power supply side faults. It is currently recognized as the most reliable and flexible power supply method. In order to prevent the unbalanced output of each power supply line due to the voltage of the equivalent power supply, the equivalent impedance difference of the power supply line, and the uneven load distribution on the medium voltage side, the traditional point network is equipped with reverse power on the low voltage side. Protect. When the protection detects reverse power, it takes action and trips the short circuit. The traditional reverse power protection is...

AI Technical Summary

Problems solved by technology

However, with the access of distributed power, due to the fluctuation and randomness of its output, under the condition that the load is light and the output of distributed power is large, the traditional reverse power protection detects the Reverse power will cause malfunction and reduce the reliability of point network power supply

At present, the commonly used countermeasures are to limit the output of DERs, which is not conducive to the development of distributed energy generation technology

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