A method for diagnosing a failure of an inverter switch of a motor drive system

Abstract

The application belongs to the field of inverter switch fault diagnosis, and proposes an inverter switch fault diagnosis method of motor drive system. Based on the slope difference of adjacent time current vector trajectory trend line, the power switch open circuit fault diagnosis of motor drive inverter system is carried out, the detection threshold is set through the difference of adjacent trend lines, the open circuit fault can be identified, and the detection variable is set by using the adjacent trend line slope in the alpha-beta coordinate system and the current direction of the beta axis to locate the fault power switch. The method can not only handle the load change, but also diagnose the fault of single tube and multi tube switch tube. At the same time, the method can quickly detect the open circuit fault, and only a small amount of current node signal is needed to realize fault diagnosis, so the method is suitable for ring implementation, and the method has good robustness to load.

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