Fault-tolerant five-phase permanent magnet motor drives

In this paper, a control strategy that provides fault tolerance to five-phase permanent magnet motors is introduced. In this scheme, the five-phase permanent magnet (PM) motor continues operating safely under loss of up to two phases without any additional hardware connections. This feature is very important in traction and propulsion applications where high reliability is of major importance. The five-phase PM motors with sinusoidal and quasi-rectangular back-EMFs have been considered. To obtain the new set of phase currents to be applied to the motor during fault in stator phases or inverter legs, the torque producing MMF by the stator is kept constant under healthy and faulty conditions for both cases. Simulation and experimental results are provided to verify that the five-phase motor continues operating continuously and steadily under faulty conditions.