Application of ultracapacitors in electric vehicle propulsion systems

A study was performed to determine design specifications for ultracapacitor type devices to be used in electric vehicle propulsion systems and their effect on battery power requirements and vehicle range and performance using different types of traction batteries. The design requirements for the ultracapacitors are discussed. Computer simulations of electric vehicles with battery load leveling were performed and the results of the simulations for 4-passenger cars and minivans are discussed. The current status of pulse power devices, both double-layer ultracapacitors and bipolar lead-acid batteries, is summarized. Consideration of the characteristics of ultracapacitors and bipolar lead-acid pulse batteries for the pulse power device indicates that either device could be used, but the efficiency of the system would be greater by about 10% by using the ultracapacitors.<>