Design and Optimization of an Electric Vehicle Wireless Charging System Using Interleaved Boost Converter and Flat Solenoid Coupler

Abstract

Simple but effective output voltage/current control schemes are essential for electric vehicle wireless charging systems (EVWCSs). This article proposes an EVWCS using interleaved boost converter (IBC) and flat solenoid coupler (FSC). The closed-loop control between the primary and secondary is realized by adjusting the duty cycle of the IBC. The currents and losses in the primary are reduced in the proposed system because the dc bus voltage in the primary is increased by using the IBC. The input current ripple is diminished owing to the interleaved structure. This article also proposes a parameter optimization method to obtain the optimal FSC. Without loss of generality, the total area of the transmitter (Tx) and receiver (Rx) is assumed to be constant, and the Tx is assumed to be larger than the Rx. A scale-down prototype whose output power is 500 W was built in the laboratory to verify the theoretical analysis. The output voltage of the prototype kept constant when the misalignment was 200 mm in the winding direction or 100 mm in the magnetic direction. A highest system efficiency, from dc input to dc output, of 90.1% was achieved when the power transfer distance was 170 mm.