Hierarchical fault diagnosis method based on transient current information and wavelet entropy

Abstract

The invention discloses a hierarchical fault diagnosis method based on transient current information and wavelet entropy. Topological structure analysis is firstly carried out on a distribution network; three-phase current information at a bus outlet is then acquired, a fault component is extracted, and a happening short circuit fault type is judged; the corresponding transient current information is then extracted to judge the general range of the happening fault, wavelet packet decomposition calculation is then carried out on the fault current in the range, a wavelet entropy value of signals is obtained, the value is then uploaded to a main station, and the main station judges the specific line of a fault point according to the wavelet entropy value of each detection point. The hierarchical fault diagnosis method based on transient current information and wavelet entropy has the advantages of few switching action times, quick fault point recognition, and comprehensive recognized fault types.

Description

technical field [0001] The invention relates to a hierarchical fault diagnosis method based on transient current information and wavelet entropy. Background technique [0002] The power system mainly includes four main links of power generation, power transmission, power distribution, and power consumption. Among them, power transmission and distribution are in the middle part of power generation and power consumption, and are extremely important links in the power system. With the release of "Several Opinions on Further Deepening the Reform of the Electric Power System" (Zhongfa [2015] No. 9), a new round of electric power reform has kicked off. The most important changes are the separation of plant and network, and the separation of transmission and distribution. The security, stability, and rapid recovery of distribution networks have received more and more attention. Distribution network fault detection is a very important part of the distribution network. Once the dis...

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Problems solved by technology

[0005] 1) When a fault occurs, sometimes the steady-state fault current generated is small, and the fault component may not be detected when using the steady-state current information for fault detection, so that the fault point cannot be detected

[0006] 2) Some fault detection methods require multiple actions of the section switch or the circuit breaker, causing the line to be subjected to the secondary impact of the short-circuit current and reducing the service life of the switch

[0007] 3) Some fault detection methods are greatly affected by the distribution network structure and line parameters, which may cause misjudgment when selecting faulty lines

[0008] 4) Some distribution network fault detection methods can only judge the ground fault in a single way, or are only applicable to the distribution network with simple structure, and cannot effectively protect the distribution network

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