Direct Matrix Converter-Based Modular High-Power Wireless Charging Systems for Heavy-Duty Electric Vehicles

Abstract

Due to the increasing demand for high-power charging in heavy-duty electric vehicles (HDEVs) and the inherent limitations of conductive charging, the development of a modular wireless power transfer (WPT) charging system has become indispensable. However, most existing studies rely on conventional two-stage AC-DC-AC converters at the primary side, which limit power density and reliability because of the bulky DC-link electrolytic capacitors. This paper proposes a novel modular medium-voltage AC (MVAC) grid-connected WPT system based on direct matrix converters (DMCs). A full-bridge DMC (FBDMC)-based WPT system is proposed with a simple fixed 50 % duty-cycle modulation strategy. Analytical and simulation results verify that the AC-input FBDMC-based WPT system can be equivalently represented by a DC-input fullbridge inverter-based WPT system with the same seriesseries compensation, RMS input voltage, and modulation. To achieve higher power transfer capability, scalability, and efficiency, input-series output-parallel (ISOP) and inputparallel output-series (IPOS) modular topologies are investigated. The simulation results demonstrate that, when connected to the MVAC grid using the ISOP configuration, the system is capable of delivering power at the hundred-kW to MW level. The proposed topologies are verified by the downscaled experimental platform. The FBDMC-based prototype achieves an output power of 2.51 kW with a grid-to-load efficiency of 91.6 % at 230 VAC. The IPOS and ISOP configurations are experimentally validated using two modular half-bridge DMC (HBDMC) modules derived from the FBDMC design.