Optimal Design of Outer Rotor Switched Reluctance Machines for Direct Drive Rim Applications

Abstract

This paper discusses the optimal design of external rotor switched reluctance (SR) machines for direct drive applications. The machines considered for this study include SR motors with a higher number of rotor poles than stator teeth; machines employing a larger number of stator teeth than rotor poles, as well as machines with segmented rotor constructions. Differential evolution is utilized for the optimization, and two objectives, of mass and loss are considered. A comprehensive comparison of the mass, loss, and inverter VA rating required to meet target torque for all three studied machine was performed, in which, hundreds of candidate designs were analyzed. The calculations are also benchmarked with results from a prototype motor.