Extending speed range of five-phase PM machines by changing the stator windings connections

Multi-phase permanent magnet machines are good candidate for electric vehicle (EV) and hybrid electric vehicle (HEV) applications due to their fault tolerance capability, high torque to current ratio, high efficiency and fast dynamic response. However limited speed range is a major drawback for these electric machines. Stator winding configuration has a significant effect in speed range operation of AC electric machines. In a three phase AC machine a wide speed range operation can be achieved by changing the stator winding connection from wye to delta. In this paper the performance of a five-phase permanent magnet machine with different winding configurations for the stator is investigated. Simulation results are carried out to show the performance of each stator winding connections over a wide speed range.