Low voltage power distribution line line breaking fault identification method and low voltage power distribution line line breaking fault identification device

Abstract

The invention provides a low voltage power distribution line line breaking fault identification method and a low voltage power distribution line line breaking fault identification device. Fourier transform of a phase line current signal and a total leakage current signal of a first preset sampling point and Fourier transform of a total leakage current signal, an A phase current signal, a B phase current signal, and a C phase current signal of a second preset sampling point are carried out to acquire the amplitudes and the phase angles of the above mentioned various signals, and based on the amplitude, the phase angles, and the current setting values of the above mentioned various signals, whether a single-phase branch protection criterion and / or a three-phase main branch protection criterion are / is satisfied is determined. By combining the 220V single-phase branch protection criterion and the 380V three-phase main branch protection criterion together, a complete fault detection and protection system is provided for low voltage power distribution system line breaking faults, and faults of a three-phase power distribution wire main branch and faults of a single-phase branch power distribution wire are identified accurately, and therefore whether a protection device is required to cut the faulted line is determined.

Description

technical field [0001] The invention relates to the technical field of fault diagnosis of power distribution lines, and more specifically, to a method and device for identifying disconnection faults of low-voltage power distribution lines. Background technique [0002] Generally speaking, the distribution network refers to the power network with a voltage level of 35kV and below, and its function is to supply power to various distribution stations and various electric loads in the city. At present, the power distribution lines in most cities in my country use 10kV voltage level to supply power to users. Distribution lines have a wide distribution area and a long total length, but the operating environment is harsh, and they are prone to disconnection faults due to lightning strikes, external mechanical forces, and line load overloads, which seriously threaten the safety and reliability of power supply. After a disconnection fault occurs in the line, the voltage quality of t...

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Problems solved by technology

[0004] Although the existing technology solves the problem of disconnection fault detection in 10KV distribution lines, it does not provide a solution for the detection of disconnection faults and fault type identification of low-voltage distribution lines such as 380V / 220V

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