ADVANCED ELECTRIC PROPULSION SYSTEM CONCEPT FOR ELECTRIC VEHICLES

摘要

The objective of this study was to evaluate 17 propulsion system concepts for electric vehicles, and to make conceptual designs of the two most promising configurations. The preliminary analysis compared all systems on a common basis of performance to determine the differences in components and battery pack to achieve the basic performance level. Design tradeoffs were made for selected configurations to find the optimum component characteristics required to meet all performance goals. Comparisons were made not only of range, but also of acceleration and cost. An evaluation was also made of the anticipated performance when using nickel-zinc batteries rather than the standard lead-acid batteries. The two systems selected for the final conceptual design studies included a system with a flywheel energy storage unit and a basic system that did not have a flywheel. Both systems meet the range requirements of 161 km with the SAE J227a schedule D cycle and 209 km at a constant 89 km/hr. The flywheel system meets the range requirement with either lead-acid or nickel-zinc batteries and also the acceleration of zero to 89 km/hr in 15 s. The basic system can also meet the required performance with a fully charged battery, but, when the battery approaches 20 to 30 percent depth of discharge, maximum acceleration capability gradually degrades, although the other performance goals can be met. The flywheelsystem has an estimated life-cycle cost of $0.041/km using lead-acid batteries. The basic system, due to the more strenuous demands on the battery, has a life-cycle cost of $0.06/km. The basic system, using batteries meeting ISOA goals, would have a life-cycle cost of $0.043/km. (ERA citation 05:026083)