BEV Range Improvement Using Highly Efficient Downsized DC-DC Converter

The optimization of a motor drive system of the battery electric vehicle (BEV) is a tradeoff among vehicle performance requirements, system efficiency and cost. In this paper, a drive system with the downsized buck-boost converter is proposed to decouple the design considerations of peak drive performance and drive cycle efficiency at a relatively low cost. The concept is verified by the detailed analysis of the system losses and energy consumptions following by the transient performance simulation. The study shows 9.7% reduction of energy consumption over average drive cycle which results in 2% vehicle range improvement. To verify the simulation analysis, a prototype system was built and tested in the lab. The test results exhibit a close agreement with the predicted performance.