Inductive Wireless Power Transfer Systems for Low-Voltage and High-Current Electric Mobility Applications: Review and Design Example

Along with the technology boom regarding electric vehicles such as lithium-ion batteries, electric motors, and plug-in charging systems, inductive power transfer (IPT) systems have gained more attention from academia and industry in recent years. This article presents a review of the state-of-the-art development of IPT systems, with a focus on low-voltage and high-current electric mobility applications. The fundamental theory, compensation topologies, magnetic coupling structures, power electronic architectures, and control methods are discussed and further considered in terms of several aspects, including efficiency, coil misalignments, and output regulation capability. A 3D finite element software (Ansys Maxwell) is used to validate the magnetic coupler performance. In addition, a 2.5 kW 400/48 V IPT system is proposed to address the challenges of low-voltage and high-current wireless charging systems. In this design, an asymmetrical double-sided LCC compensation topology and a passive current balancing method are proposed to provide excellent current sharing capability in the dual-receiver structures under both resonant component mismatch and misalignment conditions. Finally, the performance of the proposed method is verified by MATLAB/PSIM simulation results.