PROPULSION SYSTEM-DESIGN OF ELECTRIC AND HYBRID VEHICLES

There is a growing interest in electric and hybrid electric vehicles d ue to environmental concerns, Recent efforts are directed toward devel oping an improved propulsion system for electric and hybrid-electric v ehicles applications, This paper is aimed at developing the system des ign philosophies of electric and hybrid vehicle propulsion systems, Th e vehicles' dynamics are studied in an attempt to find an optimal torq ue-speed profile for the electric propulsion system, This study reveal s that the vehicles' operational constraints, such as initial accelera tion and grade, can be met with minimum power rating if the power trai n can be operated mostly in the constant power region, Several example s are presented to demonstrate the importance of the constant power op eration, Operation of several candidate motors in the constant power r egion are also examined, Their behaviors are compared and conclusions are made.