Operating Area Analysis of Direct and Geared Brushless-DC Motor Drives for Electric Bicycles

We use different measured bicycle riding profiles to determine the steady-state and the dynamic operating area requirements of electric bicycles. We use these data to discuss techniques to investigate the technical performance of direct and of geared brushless-DC motor drives for such applications, including efficiency-maps and -contours. Both sides of the gear are considered. The analysis shows the large influence of the control-method on the drive operating area and the reduction of the drive operating area but at a higher drive efficiency with higher gear ratios.