Comparative Evaluation of 6/8 and 6/10 Switched Reluctance Machines for Traction Application in Plug-in Hybrid Electric Vehicles

Switched reluctance machine (SRM) is an attractive candidate for traction applications owing to its simple structure, robustness to harsh operating conditions and wide extended speed constant power range. Conventional SRM has higher number of stator poles than the rotor poles. Configurations with higher number of rotor poles using the new pole design (PD) formula, takes SRM one step further in traction applications by improving its output torque with lower torque ripple. However, higher number of rotor poles brings important geometrical restrictions on the dimensions of the machine. This paper compares two possible 3 phase SRM configurations with higher number of rotor poles to have more flexible design in geometry. The effect of decrease in the number of rotor poles is investigated using finite element analysis on the performance and volume of a 5hp SRM model for a traction application.