Research on Parameter Optimization of Electric Vehicle Wireless Power Transfer System

Double-side LCC topology (DS-LCC) is widely used in electric vehicle wireless power transfer system because of its constant current output characteristics independent of load. However, the traditional symmetric parameter design method does not take full advantage of its high design freedom, making it difficult to further improve the system efficiency. Aiming at this problem, an asymmetric parameter design method is proposed to improve the system efficiency without changing the main parameters of the system, i.e., the compensation parameters are redesigned by changing the ratio of two compensation inductors. And on this basis, the compensation capacitors are further optimized to realize the zero-voltage switch (ZVS) of the inverter, and the parameter ratios of the best efficiency point are established. Finally, the system feasibility was verified by building a 3 kW experimental prototype, and the experimental results showed that the optimized efficiency reached up to 92.7% and improved 1.3%~1.4% over the pre-optimized system efficiency in the full power range.