Optimized LCC-Series Compensated Resonant Network for Stationary Wireless EV Chargers

In this paper, an optimal design procedure for LCC-series compensation network is proposed for a stationary wireless electric vehicle charger. The main focus of this paper is to optimize the resonant network suitable for a wide range of operation from no-load to full-power operation. The conventional methods only consider the full-load condition to design the resonant network; in contrast, the proposed method employs a time-weighted average efficiency for different coupling conditions to achieve high efficiency over a wide load range including light-load and no-load operation. The resonant network is tuned to realize zero voltage switching for the primary side inverter. Moreover, a finite-element analysis is performed to calculate self- and mutual inductances as well as core losses for magnetic couplers. In order to validate the feasibility of the proposed design, a 1 kW/85 kHz prototype with circular magnetic couplers is implemented. According to simulations and experiments, flat profiles for both efficiency and output voltage against output power variations are achieved. Experimental results demonstrate a 94.8% peak efficiency for the full-load operation.