A Wireless Power Transfer System with Reduced Output Voltage Sensitivity for EV Applications

This paper presents a design procedure for LCC-Series compensation network for Wireless Power Transfer (WPT) system for Electric Vehicle (EV) applications. DC-link voltage variations is common in the gird connected power converters due to using diode rectification. These voltage variations could be reflected to the load side in a WPT system. The main focus of this paper is to design the resonant circuit to minimize the output voltage sensitivity respect to the input voltage variations. The resonant network is also tuned to realize Zero Voltage Switching (ZVS) for the primary side inverter to minimize the switching losses. Furthermore, a Finite Element Analysis (FEA) 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 22 kW/85 kHz WPT system with circular magnetic couplers is simulated. According to the frequency domain analysis the proposed circuit has 32% less sensitivity to the input voltage variations in comparison with the conventional design.