Analysis of nine-phase induction motor under unbalanced supply

The motor is supplied by an inverter,which may be excepted to be well-balanced.However a voltage mismatch is measured between phases on the experimental system which would influence the performance of motor.Aiming at this problem,the multi-phase concentrated full-coil winding induction motor was analyzed under unbalanced supply.A finite element analysis was used to calculate and analyze a nine phase motor under unbalanced supply,and the performances was compared.The results indicate that the performance of multi-phase induction motor under unbalanced supply will be different from balanced supply,especially in the phase current and the torque ripple.It will produce positive sequence voltage and negative sequence voltage which will influence the phase current and torque ripple.