Matrix converter switch open circuit fault diagnosis method based on prediction control

Abstract

The invention discloses a matrix converter switch open circuit fault diagnosis method based on prediction control. The method comprises the following steps of under the condition that a matrix converter works normally, establishing relation models between an output voltage and an input voltage, and between an input current and a load current; determining numbers of all the switch combination states of the matrix converter; establishing a state space model and acquiring predicted values of the load current, the input current and the input voltage in a next sampling period; determining an evaluation function; using a finite set model prediction control strategy to select a switch state capable of making an evaluation function value be minimum in all the switch combination states in each sampling period and using the switch state as the switch state of the next sampling period; establishing the state space model and acquiring a change rule of a fault phase load current after a switch open circuit fault is generated; carrying out on-line monitoring on the load current, according to a finite set model, predicting and controlling the selected switch state so as to carry out fault diagnosis, and identifying a fault switch position. By using the method, an open circuit fault can be timely diagnosed.

Description

technical field [0001] The invention relates to the field of circuit fault diagnosis, in particular to a predictive control-based matrix converter switch open circuit fault diagnosis method. Background technique [0002] In recent years, with the rapid development of power electronics technology, many new power converters have emerged. Among many AC-AC converters, the matrix converter can realize the conversion of all AC parameters (phase number, phase, amplitude, frequency) , and has attracted the attention of a large number of scholars with its unique advantages. Compared with traditional converters, matrix converters have the following advantages: no intermediate DC energy storage link, four-quadrant operation, compact power supply design, excellent input current waveform and output voltage waveform, energy can flow in both directions, volume Small size, light weight and free control of input power factor etc. In addition, since the matrix converter does not have electr...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a matrix converter switch open-circuit fault diagnosis method based on predictive control to solve the technical problem that the switch device of the matrix converter cannot be found in time when an open-circuit fault occurs

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