Design and Control of Optimized Switched Capacitor for EV Wireless Power Transfer Systems Considering Wide Coupling Coefficient Range

This paper proposes an output voltage control method of an inductive power transfer (IPT) system for electric vehicles (EVs) considering the coupling coefficient variation as a result of magnetic pad misalignment. Since the output voltage of the IPT converter corresponds to the input voltage of the DC-DC converter, an excessively wide output voltage range increases the burden on the DC-DC converter. Therefore, a method of limiting the output voltage range of the IPT converter by applying a switched capacitor method is proposed. A 7.2kW class IPT system is designed, and the compensation topology characteristics determined by the switched capacitor are analyzed. Finally, the feasibility of the output voltage control method proposed in this paper was verified by experiment.