A 6.6-kW High-Frequency Wireless Power Transfer System for Electric Vehicle Charging Using Multilayer Nonuniform Self-Resonant Coil at MHz

A high-power, high-frequency wireless power transfer system for electric vehicles (EVs) is proposed in this article with lightweight and compact coil design. Leveraging a multilayer nonuniform self-resonant coil, no external capacitor is needed for compensation and the high-frequency conduction loss is mitigated by sharing current between multiple copper layers. The analytical model for the proposed coil is provided, and prototype coils with 200-mm radius are fabricated and tested, achieving a quality factor over 450 at 3 MHz. The optimized design for both coils and a GaN-based power stage are detailed and validated experimentally. Experimental tests show 95.2x0025; dcx2013;dc efficiency with 6.6-kW power transferred across a 100-mm coil-to-coil distance with 52.5 kWx002F;m(2) power density. The system demonstrates the first 6.6-kW wireless power transfer system for EV charging using compact self-resonant coils at MHz.

Automated summary

This article proposes a high-power, high-frequency wireless power transfer system for electric vehicles (EVs) with lightweight and compact coil design. The system utilizes a multilayer nonuniform self-resonant coil to eliminate the need for external capacitors and mitigate high-frequency conduction loss. Experimental tests demonstrate 95.2% efficiency and 52.5 kW/m² power density with 6.6 kW power transferred across a 100-mm coil-to-coil distance. This system showcases the first 6.6-kW wireless power transfer system for EV charging using compact self-resonant coils at MHz frequency.