Judgment method of line-to-ground fault

Abstract

The invention discloses a judgment method of a line-to-ground fault. A device used in the judgment method comprises a converging unit of an externally applied signal generation device and a transientwave recording type fault indicator which are in communication connection with a master station and mounted on a distribution network line as well as at least one collecting unit with a wave recordingfunction; whether the fault happens is judged by the externally applied signal generation device and the transient wave recording type fault indicator, characteristic waveforms are emitted by the externally applied signal generation device, the at least one collecting unit performs wave recording on the line and uploads wave recording information to the master station, and the master station analyzes whether the ground fault occurs at a corresponding line node according to the wave recording information. According to the method, the advantages of the existing two fault indicators are combined, application defects of the two fault indicators are overcome by mutual complementation, and the judgment accuracy rate of the ground fault is remarkably increased.

Description

technical field [0001] The invention relates to the field of line fault judgment of 6-35KV distribution network, in particular to a line grounding fault judgment method. Background technique [0002] my country's 6-35KV distribution network has the characteristics of intricate network topology, wide range of erection, and low level of intelligence. Fault indicator equipment can help power grid operation and maintenance personnel quickly find fault lines and determine and locate fault areas, so fault indicator equipment is widely used on distribution lines. The traditional fault indicator can normally judge the phase-to-phase short-circuit fault, but the accuracy of the judgment of the ground fault is low. At present, the fault indicators that can judge the ground fault mainly include externally applied signal fault indicators and transient state recording type fault indicators. [0003] The detection principle of the externally applied signal type fault indicator: when the...

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Problems solved by technology

[0008] ② The characteristic signal collected by the acquisition unit of the fault indicator may be too small to judge the fault;

[0009] ③Only applicable to steady-state grounding, not suitable for unsteady-state grounding faults such as arc grounding

[0011] ① Excessively affected by the environment, it is easy to make false alarms and false alarms in thunderstorms, heavy fog and other weather conditions. The root cause is that the spatially distributed capacitance between the wire and the ground is greatly affected by humidity;

[0012] ②The electric field voltage signal is affected by the accuracy of the internal voltage divider capacitor, and there is a phase shift

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