Instantaneous power spectrum analysis for broken bar fault detection in inverter-fed six-phase squirrel cage induction motor

• A model of six-phase induction motor using winding function approach is given.
• The instantaneous power is developed using the Fourier series approach.
• An analytical analysis reinforced by simulation results is given.
• The proposed method is confirmed by experiment tests.
• The appearance of certain harmonics facilitates the detection of broken bar.

Many researches deal with the detection of broken bar fault in three-phase induction motor, however in high-power applications the multiplication of phases number allows the segmentation of the power on more than three phases which reduces the price of power electronic device and gives greater fault tolerance in open phases. For this reason, it becomes very interesting and demanding to detect faults in case of n>3n>3 phases induction motor. In this study, a novel investigation of broken bar faults in instantaneous power spectrum is presented. The method is based on calculations and frequency analysis of instantaneous six-phase power spectrums when the motor is fed by PWM six-phase IGBT voltage source inverter (VSI). The used model takes into account the geometry and winding layout. The analytical study is confirmed by simulation and experimental results.