Overview

It appears very unlikely that a specific powertrain architecture would be suitable for all vehicles in all markets. Today series and series parallel switching architectures are either in production or under prototype development for city buses, commercial trucks and other heavy vehicles. Pre-transmission parallel and power split architectures have found their principal application in passenger vehicles in the compact and midsize segments. Sub-compact and compact vehicles, including minivans, are being converted to CVT hybrids, where the continuously variable transmission, generally of the belt type, has integrated into it the traction M/G. Because of the high actuation forces necessary in a CVT, an ancillary electric drive for the oil pump is necessary, generally in the 2 to 2.5 kW power rating. Higher rated power split and series parallel switching configurations are being introduced in small sport utility and larger vehicles. Fuel cell powered vehicles are strictly series hybrids because electric propulsion is the only option.

All the major automotive companies have developed, or are developing, fuel cell powered vehicles. Daimler-Chrysler Corp., for example, began their developments with the NECAR3 followed by NECAR4 and NECAR5. DCX also converts production vehicles to fuel cell powered alternative drive concepts such as their Jeep Commander 2, and Chrysler Town and Country minivan, the Natrium. Honda Motor Co. is a clear front runner in fuel cell powered vehicles since they have gone into limited production of the FCX ^[1] minivan in 2002. The FCX is developed around a Ballard Power Systems 78 kW PEM fuel cell...