Thyristor fault diagnosis method for series 12-pulse phase-controlled rectifier circuit

Abstract

The invention discloses a thyristor fault diagnosis method for a series 12-pulse phase-controlled rectifier circuit. The thyristor fault diagnosis method comprises the steps of 1, determining the number of thyristor fault state types in the series 12-pulse phase-controlled rectifier circuit; 2, extracting fault features by adopting a periodic and discretization method; 3, collecting a fault sample; 4, performing learning training on the sample by using a PNN network; 5, classifying the fault conditions; and 6, performing performance test on the fault of the actual circuit, and verifying the feasibility of the method. The design is novel, simple and feasible, the processing method for discrete sampling and normalization of the continuous periodic waveform has the advantages of high diagnosis precision, high diagnosis speed and simple steps; the signal processing link overcomes the defects that once a sample interval in wavelet change processing stationary signals is established, the sample interval is difficult to change and the flexibility is insufficient, and the fault mode link overcomes the defects that a neural network detection method is weak in normative ability and is easy to fall into local minimum points.

Description

technical field [0001] The invention belongs to the technical field of fault diagnosis of power electronic devices, and in particular relates to a method for fault diagnosis of a thyristor of a series 12-pulse phase-controlled rectifier circuit. Background technique [0002] Power electronics technology is not only an important part of modern industrial systems, but also the key to the development of the electrical automation industry. Studying the faults of power electronic circuits is helpful for predicting, identifying, diagnosing and repairing the faults of various components in power electronics and electric drives, which is of great significance to the electric power industry and related industries. Power electronics fault diagnosis technology mainly includes fault test point selection, fault signal processing and feature extraction, fault classification and identification and other steps. Taking the rectifier circuit as an example, the fault diagnosis system generall...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a method for diagnosing thyristor faults in series 12-pulse phase-controlled rectifier circuits to solve the problem of wavelet changes in the processing algorithm for periodic fault voltage signals in the prior art and for fault sample intervals in processing smooth signal algorithms Once established, it is difficult to change and lack of flexibility. The fault pattern recognition link overcomes the defects of weak generalization ability and easy to fall into local minimum points of neural network detection methods.

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