Single-phase-to-ground fault section location method in distribution network based on generalized grouping knapsack

Abstract

The invention provides a power distribution network single-phase grounding fault section positioning method based on a generalized group knapsack. Traditional fault positioning algorithms based on a power system transient signal all adopt a fixed basis function to decompose the signal and have the problems of insufficient decomposition accuracy and redundant decomposition results. The invention proposes to use a sparse decomposition theory to extract an attenuation DC component in the power system transient signal, and an area where the single-phase grounding fault is located is judged according to the existence of the attenuation DC component. In order to overcome the problem of huge space-time complexity of a sparse decomposition theory classical MP algorithm, a generalized group knapsack model is constructed based on dynamic programming, and a linear combination of selected atoms approximates an original transient signal with O(VN) time complexity. According to the method, the basisfunction can be adaptively selected according to the characteristics of the transient signal to obtain a simplest form of signal decomposition, and a new idea is provided for the single-phase groundfault positioning method of the power distribution network.

Description

technical field [0001] The invention belongs to the field of relay protection of electric power systems, relates to fault location of distribution networks, and in particular to a method for locating single-phase grounding fault sections of distribution networks based on generalized grouping backpacks. Background technique [0002] With the continuous increase of power system scale, the reliability of distribution network plays an increasingly important role in the national economy. The distribution network is a link that directly faces users, and its reliability is related to the production and life of power users, and its importance is self-evident. In distribution network faults, single-phase-to-ground faults occupy a dominant position. How to accurately locate the fault area, isolate the fault section, and eliminate the ground fault in a limited time is of great significance to the reliability of the distribution network. [0003] Among the segment location algorithms ...

AI Technical Summary

Problems solved by technology

The EMD empirical mode decomposition algorithm has serious endpoint effects, and it is easy to accumulate errors in the fitting process, which eventually leads to distortion of the decomposition results.

The PRONY algorithm has a huge amount of calculation, and it uses damping harmonic decomposition signal, which is very sensitive to noise

The wavelet decomposition algorithm is non-adaptive and cannot select basis functions according to the characteristics of the input signal

The limitation of the above algorithm comes from the use of a fixed basis function to decompose any signal. Since the actual transient signal contains a large amount of information and is very complex, the decomposition method using a fixed basis must have limitations.

In the field of signal sparse decomposition, the classic MP algorithm is a greedy algorithm that approximates the original signal through repeated iterations, because its huge time-space complexity is difficult to adapt to the timeliness of the power system relay protection field

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