Efficiency Enhancement of Multi-Coil WPT Using Phase-Shift and Coil Tilt-Angle Control Method

This paper presents a control method to enhance the power transfer efficiency (PTE) of multi-coil wireless power transfer (WPT) via magnetic resonance coupling (MRC). The proposed method applies optimized phase-shifts and varying coil tilt angles at the transmit (TX) coils to ensure maximum power transfer. The experimental results demonstrate that the PTE is higher than 20% compared to the conventional one without such method, thereby ensuring high transfer efficiency needed for portable wireless charging applications.