Distribution network line fault positioning method based on fault current discharge path

Abstract

The invention discloses a distribution network line fault section positioning method based on correlation coefficients. For a grounding fault, the characteristics of the phase current before the occurrence of the fault and during the period from the occurrence of the fault till the actuation of an arc-suppression coil are analyzed, and then the fault characteristic quantity is extracted therefrom. Meanwhile, the fault is positioned based on waveform correlation coefficients during the whole process. According to the technical scheme of the invention, only the phase current of the line fault needs to be measured, so that the method is simple in scheme and strong in applicability. The current widespread problems of a small-current grounding system, such as weak fault current, poor reliability and low sensitivity during the occurrence of a single-phase grounding fault, can be well solved. Meanwhile, no interference is introduced into the system at the same time.

Description

technical field [0001] The invention relates to a method for diagnosing a distribution network line fault, in particular to a method for locating a distribution network line fault section based on a fault current discharge path. Background technique [0002] According to statistics, during the operation of the power system, power outages caused by distribution network faults account for more than 95% of the total power outages, of which 70% are caused by single-phase ground faults or busbar faults. The neutral point of domestic and foreign distribution networks widely adopts non-effective grounding (small current grounding) to avoid power supply interruption when a single-phase grounding fault occurs. For single-phase-to-ground faults in distribution networks, due to weak fault characteristics, there has been a lack of reliable fault line selection and location methods. With the improvement of people's requirements for distribution network automation level, it is more urgen...

AI Technical Summary

Problems solved by technology

[0004] It can be seen that the current methods only use the data after the fault occurs, while ignoring the use of the information before the fault.

At the same time, most positioning methods only consider zero-sequence current information (three-phase information is required), which requires high transformers and complicated information acquisition, and these methods will fail when the data is missing

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