Multilevel inverter fault diagnosis strategy based on principal component analysis and multi-classification related vector machine(PCA-mRVM)

Abstract

The invention discloses a multilevel inverter fault diagnosis strategy based on a principal component analysis and multi-classification related vector machines (PCA-mRVM). The multilevel inverter fault diagnosis strategy includes: subjecting primary samples to dimensionality reduction through principal component analysis, and extracting multiple principal components with fault features so as to form training samples; subjecting the training samples to fault diagnosis through the multi-classification related vector machine, outputting probabilities of fault classifications, and taking the fault classifications with the maximum probabilities as diagnosis results. The multilevel inverter fault diagnosis strategy has the advantages in the fault diagnosis with larger sample space and more classifications, is high in model sparseness, low in computation complexity and the like; most importantly, the probabilities of classification members can be outputted through the mRVM, probability and statistic significance is achieved, and uncertain problems can be conveniently analyzed.

Description

Technical field: [0001] The invention relates to the fault diagnosis of multilevel inverters in the field of power electronics, in particular to a fault diagnosis method based on PCA-mRVM. Background technique: [0002] With the development of power electronic technology and the reduction of production cost of power electronic devices, high-voltage high-power converters are widely used in various electrical equipment, such as high-power AC motor drive, active power filter and new energy grid connection, etc. In order to meet the ever-increasing development needs of power systems, multilevel inverters, as a new type of converter, are the most suitable for high-voltage and high-power conversion in the field of power electronics because of their simple main circuit structure and very flexible control circuits. An active branch that has been rapidly promoted in industrial production. Among them, the cascaded H-bridge inverter is widely used because it does not require a large n...

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Problems solved by technology

[0004] The technical problem to be solved by the present invention is to propose a fault diagnosis strategy suitable for cascaded H-bridge multi-level inverters aimed at the above-mentioned technical problems of the prior art, and its purpose is to overcome the generalization existing in the prior art Poor ability, high cost, slow diagnosis speed and other shortcomings, by using FFT to convert the sample data from the time domain to the frequency domain, so as to facilitate the extraction of fault feature samples, followed by PCA to reduce the dimension, reduce the amount of calculation, etc., and finally use mRVM, It can output the membership probability of each category, and the output has probability and statistical significance, which is convenient for analyzing uncertainty problems

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