Power distribution network single-phase earth fault positioning method based on morphological wavelet analysis noise elimination.

Abstract

The invention discloses a power distribution network single-phase earth fault positioning method based on morphological wavelet analysis noise elimination. The method comprises the steps of firstly analyzing a power distribution network structure so as to set a reasonable installation point of a traveling wave device, and serving the existing user side transformer as the installation point so as to maximally reduce the cost investment; for filtering pulse impact noise and white Gaussian noise in the transient power sampling signal, filtering a collected traveling wave signal by utilizing a morphological wavelet filtering method, thereby maximally improving the quality of the traveling wave waveform; and then extracting traveling wave head information by utilizing a wavelet analysis method,reading the corresponding wave head arrival time, and finally reasonably selecting a measurement combination by utilizing the combined type D-shaped traveling wave positioning method, and calculatinga branch which is most likely to have the fault and the distance between a fault point and a measurement point.

Description

technical field [0001] The invention belongs to the field of single-phase grounding fault location of distribution network. Based on mathematical morphology analysis, wavelet analysis and combined D-type traveling wave location technology, the invention aims to improve the recognition accuracy of traveling wave heads and reduce the number of faults in the location process through advanced digital filtering technology. The error generated in this paper belongs to the intersection field of signal processing and fault location, and specifically relates to a single-phase ground fault location method of distribution network based on morphological wavelet analysis and denoising. Background technique [0002] The low-current grounding system of distribution network has the highest probability of single-phase ground fault, and the fault location is also the most difficult. Therefore, the current research on fault location of distribution network is mainly concentrated in the field of...

AI Technical Summary

Problems solved by technology

However, since the frequency of the characteristic frequency band of the transient traveling wave signal is generally 10 to 100 kHz, it is necessary to use a suitable high-frequency sampler to collect when capturing the traveling wave. In addition, a large amount of noise will be introduced into the transient traveling wave signal due to reasons such as the acquisition environment, line parameters, and accidental accidents. If appropriate filtering methods are not used, the characteristic information of the traveling wave signal will be submerged in the noise, thus affecting the subsequent information extraction of transient signals

[0004] However, when using the traveling wave method for positioning, it will inevitably be affected by discontinuous impedance points, which will easily cause the rapid attenuation of traveling wave energy and fail to transmit effective information. In order to deal with this problem, a combined D-type traveling wave positioning method is adopted. This method has High detection flexibility, can use relatively reliable measurement device combination according to different fault conditions, minimize the influence of discontinuous impedance points in the measurement process

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