Influence of squirrel cage induction rotor geometry in battery C-rating

Abstract

An external rotor induction motor (ERIM) is designed to propel an electric two-wheeler with improved torque to current ratio. The torque of the optimized ERIM is significantly based on the rotor cage. The rotor’s specific permeance varies by varying the bar’s shape, increasing the motor’s torque. Likewise, maintaining the flux density below the saturation state keeps the current low. This research work proposes and studies various rotor bar shapes to improve the torque to current ratio of the motor. The proposed bars are optimized with finite element analysis (for rotor bar shape selection) and a metaheuristic approach (for rotor cage sizing). Improvement of torque to current ratio reduces the discharge C-rating of the battery, being the source for the ERIM structure.

Keywords

• C-rating
• External rotor induction motor
• Rotor bar shape
• Torque per ampere ratio