A Design Method to Implement ZVS for Electric Vehicle Wireless Charging System With Double-Side LCC Compensation

In this article, the zero voltage switching (ZVS) of the inverter in the electric vehicle wireless charging system is realized through the parameter optimization design of compensation components, which is conducive to the high efficient operation of the system. The effects of the parameter adjustment of each compensation component on the input impedance angle and output current of the double-side LCC compensation topology were analyzed under the conditions of different output voltages and coupling coefficients, which provides a basis for the component optimization design of the inverter ZVS realization. The quantitative relationship between the optimized component parameter and the soft switching implementation conditions was analyzed. Then, a specific parameter design method was proposed, according to the results analyzed earlier. At last, the effectiveness of the proposed method was verified by a 3.3-kW wireless charging system prototype. Experimental results show that the optimized system is always able to achieve soft switching, the system efficiency is up to 95.2% at the rated power, and it is higher than 93% even under the condition where the coupling coefficient and output voltage are both reduced by half.