Design Procedure of an Outer Rotor Synchronous Reluctance Machine for Scooter Application

Synchronous reluctance motors, despite their cost-effective types and wide range of speed, generally have a considerable torque ripple due to changes in magnetic resistance between the flux barriers and the stator teeth. Given the numerous possible rotor combinations with different forms of flux barriers, designing an optimal synchronous reluctance motor without the use of mathematical equations and a clear algorithm will be very time-consuming. In this study, a comprehensive method is used to design a synchronous reluctance motor with an external rotor and a flux barrier shape adopted from the behavior of fluids around a solid rotor. According to the new topology, an external rotor synchronous reluctance motor is designed. Multi-objective Taguchi optimization algorithm based on finite element analysis (FEM) is used to maximize the average torque and reduce the torque ripple.This motor is designed for 300 W electric scooters with a six-pole rotor, a 36-slot stator, and a distributed winding. Finally, a prototype of the proposed motor is constructed to validate the results of simulations. The experimental results confirm the accuracy of the design method.