Faulty Operations of a PM Fractional-Slot Motor with a Dual Three-Phase Winding

Abstract—The permanent-magnet (PM) machine with dual three-phase windings is proposed for applications requiring con- tinuous operating even under a partial fault. The two windings are supplied by two separate inverters. Thus, in the event of a fault of one winding, this is disconnected, and the machine continues to be operated by means of the healthy winding. This paper investigates the PM machine with dual three-phase windings and its capabil- ities during faulty operating conditions. A fractional-slot interior PM machine with 12 slots and 10 poles is taken into account. Its performance is investigated according to different winding config- urations. The torque behavior, overload capability, and thermal limits are evaluated under open-circuit and short-circuit faults. A finite-element analysis as well as experimental tests is carried out on a prototype of such a machine.