High Torque Capability Non-Permanent Magnet Hybrid Excited Switched Reluctance Motor for Electric Vehicle Application

Switched reluctance motors (SRMs) have become more prevalent in electric traction motors because they operate at high speeds, have optimum control, and can improve electrically driven performance with multiple phases overlapping. This can be attributed to their maximum torque per ampere and power density. The design and development of specialized electrical machines, like SRMs, have proliferated in recent years as an alternative to DC series and permanent magnet-based (PM) motors. This paper presents the design consideration and the performance evaluation of a hybrid excited non-permanent magnet assisted switched reluctance motor for electric vehicles (EV) applications. The hybrid excitation of switched reluctance motors (HESRM) is attracting considerable demand in the EV market due to its high torque performance. However, this method is currently incorporated with PM-assisted excitation to enhance the performance of SRMs. This newly designed hybrid excitation method enhances torque performance without using rare earth elements by injecting direct current (DC) through the designated auxiliary poles. The novel machine's static characteristics and dynamic performance are simulated and compared with the conventional SRM drives of the same ratings. Consequently, two motor prototypes are redesigned, and the concept is validated through experimental analysis. In all speed ranges, the proposed topologies provide significantly greater electromagnetic torque than the conventional ones. Because of its fault tolerance, multiple control topologies and redundancy were attained, thus making this machine well-suited for EV applications.