ABSTRACT
Taking advantage of the high energy density of petroleum fuels, the conventional internal combustion engine (ICE) vehicles provide good performance and long operating range. Battery-powered electric vehicles possess some advantages over conventional ICE vehicles, like high energy efficiency and zero environmental pollution. Hybrid electric vehicles (HEV), which use two power sources, primary power source and secondary power source, have both of the advantages of ICE vehicles and electric vehicles and can, overcome their disadvantages. This chapter discusses the basic concept and operation principles of the HEV powertrain. There are several configurations in torque-coupling hybrid drivetrains. These are mainly classified into two-shaft and one-shaft designs. The fuel cell-powered hybrid drivetrain is more like a series hybrid drivetrain by replacing the engine/generator system by a fuel cell system. The transmission is used to modify the speed-torque characteristics of the engine so as to match the traction requirements.
