Topologies of single-phase outer-rotor hybrid excitation flux switching motor for in wheel drive applications

Most of commercial Hybrid Electric Vehicle (HEV)used single motor and transmission gears coupled to the wheels. This system leads to the transmission losses and reduce the efficiency and reliability of the motor. Therefore, in-wheel direct drive mechanism is introduced to overcome this problem. In-wheel direct drive eliminates the mechanical transmission, differential gears and drive belts. Thus, in-wheel direct drive provides quick torque response, higher efficiency, weight reduction, and increased vehicle space. As one of alternative, a new design of hybrid excitation flux switching motor (ORHEFSM) for in-wheel drive EV is proposed. First coil arrangement tests are analyzed to confirm the phase of each armature coil phase. Then, flux comparison of PM with DC FEC, flux linkage at various FEC current densities, cogging torque, induced voltage/back EMF of PM with DC FEC, torque and power versus FEC current density at various armature coil current densities are also analyzed. The generated results show that the appropriate combination of stator slot-rotor pole configurations are 8S-4P and 8S-8P respectively, which initially provide highest torque performance and power density. By further design modification and optimization it is expected that the low cost motor will successfully achieved the target performances.