Diagnosis of multiple IGBT open-circuit faults for three-phase PWM inverters

In this paper, a novel on-line diagnosis method for multiple IGBT open-circuit faults of three-phase PWM inverters is proposed. That fault detection is based on monitoring the dwelling time of the current vector in each sector of the α-β stationary reference frame, which guarantees the robustness against false alarms. The identification process is based on the information of phase currents, which allows the diagnosis of multiple faults. The proposed diagnosis scheme is implemented without any extra hardware. The validity of the proposed diagnosis algorithm have been verified by experimental results.