Design of an External-Rotor Direct Drive E-Bike Switched Reluctance Motor

In this paper, an exterior-rotor direct-drive electric bicycle (E-Bike) switched reluctance motor has been designed, based on the performance parameters and dimensional constraints of a commercially available permanent magnet e-bike motor. Motor dimensions have been adjusted to find the best balance between power factor and motor efficiency. The efficiency maps for different rotor pole configurations are compared for 3-phase SRMs with 12 stator poles. The firing angles for each efficiency map operating point are optimized using multi-objective Genetic Algorithm optimization. During the design process, several design parameters have been evaluated and their effects have been investigated. The final design characteristics of the 1216 SRM e-bike motor are validated experimentally.