Positioning method and device for distribution network line fault point based on double sampling rate

Abstract

The invention discloses a positioning method and a device for distribution network line fault points based on a double sampling rate. Phase correlation calculation is carried out on phase current waveforms acquired by a low sampling rate measuring apparatus. A recording function of a high sampling rate measuring apparatus is started when a fault occurs. Phase current waveforms acquired by the highsampling rate measuring apparatus are processed by a short-time Fourier transform. Accurate positioning is carried out on the fault points according to a D-type traveling wave method. According to the positioning method and the device for the distribution network line fault points based on the double sampling rate, the correlation coefficient calculation is carried out on waveform data, so as tosolve the unreliable problem of the traditional amplitude triggering recording wave; correlation calculation is only carried out on low sampling rate data, so as to reduce the calculation amount and improve the fault recording triggering speed; and meanwhile, a sampling time window of the high sampling rate measuring apparatus is small, so as to not rely on the large storage capacity and reduce the cost of distribution network detection equipment.

Description

technical field [0001] The invention relates to a method for diagnosing faults of distribution network lines, and more specifically, to a method and device for accurately locating fault points of distribution network lines with a double sampling rate based on short-time Fourier transform. Background technique [0002] With the continuous development of the economy, users have increasingly higher requirements on the quality of power supply. As the part of the power grid that directly interacts with users, the distribution network has a major impact on the user's power consumption experience, and the fault location of the distribution network is particularly important. At present, the domestic distribution network mostly adopts the neutral point non-effective grounding method, the topology structure is complex, and there are many branches; the ground fault current is small, and the fault location is difficult. With the improvement of people's requirements for distribution net...

AI Technical Summary

Problems solved by technology

At present, in the field of engineering applications, the fast Fourier transform method is generally used for signal spectrum analysis. This method is the most widely used and the technology is relatively mature. However, the fast Fourier transform method cannot meet the analysis of non-stationary signals. There are unavoidable defects in the analysis of non-stationary processes, so the fast Fourier transform can only give statistical average results in the time domain or frequency domain, but cannot provide information on the localization of the time domain and frequency domain of the signal

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