Method of Expanding Operating Range for Three-phase Series-end Winding Motor Drive

This paper proposed a method of expanding operating range for three-phase series-end winding motor drive. Compared with open-end winding motor drive, the series-end winding topology can achieve the same DC voltage utilization with reduced power devices, which balance the performance and cost. However, when compared to traditional AC machine with half-bridge topology, it will increase the current stress of the intermediate leg, thereby limiting the torque capability at low speed. By proposing a new three-phase series-end winding topology for torque capability at low speed and a switching method of two series-end winding topology, the operating range is extended, and the drive power loss at low speed is also reduced. In addition, the zero crossing of phase current is used to achieve seamless switching without affecting the average output torque. Simulation and experimental results verify the advantages of topology and switching methods.