Modular Four-Channel 50 kW WPT System with Decoupled Coil Design for Fast EV Charging

Abstract

High-power wireless power transfer (WPT) is an attractive option for fast charging of electric vehicles (EVs), but the power capability of the WPT system is limited by power devices and resonant elements. This paper presents a scalable modular four-channel WPT system for fast EV charging. Owing to the modular design, the four-channel system achieves 50 kW output power with low-power Silicon devices, and the reliability and robustness of the system are significantly improved. Through the coil structure and placement design, the four-channel magnetic coupler achieves inter-channel decoupling, eliminating interference between channels, simplifying control logic, and enabling scalable modular design. The four-channel magnetic coupler also has rotational symmetry, making the system have a balanced tolerance to misalignment in both lateral and vertical directions. The proposed magnetic coupler is verified by 3-D finite element method (FEM) simulation. A modular four-channel WPT prototype is built and tested. Experiments show that the prototype can deliver 50.8 kW to load with 97% dc-to-dc efficiency over a 200-mm airgap in aligned case, and has a balanced tolerance to misalignment in both the lateral and vertical directions.