Effect of Extended-Speed, Constant-Power Operation of Electric Drives on the Design and Performance of EV-HEV Propulsion System Conference Paper uri icon


  • Vehicle dynamics requires extended-speed, constant-power operation from the propulsion system in order to meet the vehicle's operating constraints (e.g., initial acceleration and gradeability) with minimum power. Decrease in power rating will decrease the volume of the energy storage system. However, extending the constant power operating range of the electric drives increases its rated torque, thereby, increasing motor volume and weight. This paper investigates the effect of extended constant power operation on battery driven electric vehicle (BEV) propulsion system taking the change in motor weight and battery volume into account. Five BEV systems with five traction drive having different base speeds are simulated for this study. The performances of the BEVs are obtained using FUDS and HWYFET drive cycles. Two EV-HEV software packages 'V-ELPH' developed by Texas A&M University and 'ADVISOR' from NREL are used for simulation testing. Based on the simulation results, the paper defines an optimum range of the constant power region for single gear operation. Copyright 2000 Society of Automotive Engineers, Inc.

name of conference

  • SAE Technical Paper Series

published proceedings

  • SAE Technical Papers

author list (cited authors)

  • Rahman, Z., Butler, K. L., & Ehsani, M.

citation count

  • 26

complete list of authors

  • Rahman, Z||Butler, KL||Ehsani, M

publication date

  • December 2000