Design of a 65-kW Wireless Charging Station Characterized by Optimal Load Impedance Tracking Control

Abstract

This article presents the design and development of a low-level control approach for a wireless charger intended for modern electro-mobility (e-mobility) applications. It outlines future trends in the e-mobility market and technical advancements in wireless power transfer (WPT) systems, aligning them with the proposed wireless charger design methodology. A key advantage of the proposed solution is its full competitiveness with conventional wired charging stations. The primary focus of this work is the control system design for the wireless charging station (WCS), which features active and optimal load impedance tracking. This tracking adapts to varying load parameters (such as battery characteristics) and misalignments in coupling elements, ensuring maximum power transfer efficiency and high-power transfer controlled by supply voltage. The system complies fully with the SAE J2954 standard for wireless charging in e-mobility. The developed test system achieves power transfer of up to 65 kW across an air gap of 15 to 25 cm, with an overall system efficiency exceeding 95.5%.