A New Inverter Fault Detection Scheme for Nine-Phase Induction Motor Drive System

This paper presents a new fault detection method for both open-circuit and short-circuit faults in a nine-phase inverter which feeds a nine-phase induction motor. The motor phase voltages or inverter pole voltages can be used for fault detection. The proposed method uses the average value and third harmonics components in the motor phase voltages for fault detection in the inverter during the closed-loop operation of the motor drive. Conventional nine-phase space vector PWM is used for inverter control for achieving better harmonic performance. Closed-loop V/f control is employed for the nine-phase induction motor for speed-torque control. The drive system is simulated in MATLAB/SIMULINK platform. The proposed fault detection using motor/inverter voltage can accurately identify the fault condition under various load and speed conditions of the drive.