Power distribution network single-phase disconnection fault detection method and system

Abstract

The invention discloses a power distribution network single-phase disconnection fault detection method and system. The method comprises the following steps: calculating a positive sequence voltage and a positive sequence current; calculating a positive sequence voltage break variable and a positive sequence current break variable according to the positive sequence voltage and the positive sequence current; when the amplitude of the positive sequence voltage break variable is larger than a starting threshold value, calculating the phase difference beta between the positive sequence voltage break variable and the positive sequence current break variable, wherein when the phase difference beta meets the condition that beta is larger than -90 degrees and smaller than 90 degrees, the line is an intact line, and when the phase difference beta meets the condition that beta is larger than -180 degrees and smaller than -90 degrees, and beta is larger than 90 degrees and smaller than 180 degrees, the line is a fault line; and realizing broken line fault line selection according to the phase difference beta, or section positioning of broken line faults based on voltage-time type, intelligent distributed or centralized feeder lines. According to the method, three broken line forms can be considered, broken line fault line selection is realized only by depending on measurement data of each outgoing line outlet of the transformer substation, and meanwhile, the method can be combined with voltage-time type feeder automation, intelligent distributed feeder automation and centralized feeder automation to realize automatic positioning and isolation of broken line faults.

Description

technical field [0001] The invention belongs to the technical field of power systems, and in particular relates to a single-phase disconnection fault detection method and system of a distribution network. Background technique [0002] Disconnection faults in the distribution network lead to accidents such as overvoltage, motor damage, and personal electric shock. Therefore, it is necessary to propose a method that can quickly and reliably detect disconnection faults. Single-phase disconnection faults are divided into three forms: disconnection and non-ground fault, disconnection power source side ground fault and disconnection load side ground fault. The fault characteristics of the three modes are different but also show certain commonality. Contents of the invention [0003] The technical problem to be solved by the present invention is to provide a single-phase disconnection fault detection method and system for a distribution network based on the above-mentioned defici...

AI Technical Summary

Problems solved by technology

[0002] Disconnection faults in the distribution network lead to accidents such as overvoltage, motor damage, and personal electric shock casualties. Therefore, it is necessary to propose a method that can quickly and reliably detect disconnection faults.

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