A Comparative Study of the Production Applications of Hybrid Electric Powertrains 2003-01-2307

In this paper, a comparative study of the production applications of hybrid electric powertrains is presented. Vehicles studied include the Toyota Prius, Honda Insight, Toyota Estima, Toyota Crown, Honda Civic Hybrid, and Nissan Tino. The upcoming Ford Escape Hybrid and General Motors Parallel Hybrid Truck (PHT) will also be included, although advance information is limited. The goal of this paper is to look at what hybrid drivetrain architectures have actually been selected for production and what are the underlying details of these drivetrains.

Since hybridizing a powertrain involves significant changes, the powertrain architectures are presented in diagram form, with analysis as to the similarities and advantages represented in these architectures. The specific hybrid functions used to save fuel are discussed. Peak power-to-weight ratio and degree of hybridization are plotted for the vehicles. System voltage versus electric power level are also plotted and analyzed. The individual powertrain components including engine, transmission, electric motor, and battery are compared and their key technologies examined. There are a number of possible technology choices for each component and understanding which technologies were chosen and how the resulting collection works together as a system is important.

Based on the comparative study, conclusions are presented regarding these production hybrid electric powertrains and trends are highlighted.