In Pursuit of Proper BLDC Motor Design for Electric Bicycles

Abstract

In this paper, an electric bicycle motor design study is presented according to the related standard. Fundamental dimensions and characteristics are kept within some certain boundaries by means of motor rated power and physical constraints arising from standard bicycle sizes available on the market. Slot/pole ratios and winding configurations are investigated comprehensively in order to obtain a proper design of electric motor due to the facts of pedal assisted electric bicycle application. After defining the motor parameters and the materials that are used the motor design an optimisation attempts are undertaken by using an analytical solver which is employing both numerical calculations and finite element method (FEM) analyses. Motor designs are assessed based on torque production, weigh, efficiency and ease-of-manufacture. A concise experimental study is conducted for prototype motor in order to evaluate validity of design study.