Double-Sandwich Magnetic Coupling Structure Design for Dual-LCL Wireless Charging System in EV Applications

Abstract

In the wireless charging system of EVs, the traditional single-stage LC resonance network has the issues of narrower of parameter design and small equivalent input impedance. While the composite resonant network will introduce additional resonant capacitors and inductors, which increases the system volume, cost, and reduces the efficiency. This paper proposes a design scheme of double-sandwich magnetic coupling structure with a low cross-coupling coefficient, which integrates the resonant inductors into the power transmitter and receiver, and it is designed taking the magnetic leakage and loss as constraints. A 500W prototype is built, and the comparison of experimental efficiencies between the double-sandwich and the separate magnetic coupling structures is performed. Finally, the effectiveness of the integrated design scheme is validated.