Gram Matrix Based Transistor Open-Circuit Fault Diagnosis Method for Voltage-Source Inverter Fed Vector Controlled Induction Motor Drives

This paper proposed a novel, real-time and high efficiency diagnostic method for Insulated Gate Bipolar Transistor(IGBT) open-circuit fault in pulse-width-modulated (PWM) voltage- source inverter fed vector-controlled induction motor. Similarity among three phase currents of inverter can be used to detect transistor open-circuit faults according to the topological analysis of inverter operations both in healthy and failure condition. In this paper, Gram-matrix of three phase currents is proposed to extract features, the eigenvalues of the matrix are proposed to measure the similarity and diagnose transistor open-circuit fault. The proposed method is fast and fair-robust, both single and multiple faults on the same leg can be effectively detected and located. Experimental results evaluate efficiency and merits of proposed diagnostic method.