A Modular Multilevel Converter based Inductive Power Transfer System

Traditional full-bridge converters struggle to handle the increasingly higher power levels for wireless electric vehicle (EV) charging systems. As an alternative solution, this paper introduces a modular multilevel converter (MMC) based inductive power transfer (IPT) system. MMCs are traditionally used for low frequency applications (HVDC and medium voltage drive), but its high frequency operation differs significantly and is yet to be reported. Therefore, this paper focuses on the 85 kHz high-frequency operation principle of the MMC. To validate the proposed MMC based IPT system, an SAE J2954 WPT2/Z2 standard compliant prototype is built and tested, which achieved up to 92.1% efficiency when maintaining 7.7 kW power transfer while only using low-cost silicon devices.