Delta connected induction motor drive analysis under open switch converter fault

This paper investigates an electrical induction motor drive system under open switch inverter fault. The finite element analysis (FEA) is used in order to specify the effects of the open switch fault on the induction motor. The winding of the induction motor was considered delta connected. The consequences of the unbalanced inverter supply on the developed phase and line currents as well as the electromagnetic torque are studied. The unbalanced distribution, over the cross section of the machine, of the magnetic flux density time harmonics is presented. Moreover a comparison of the efficiency before and after the fault is made.