A Three-Phase WPT System with Improved Misalignment Tolerance by Using an Effective Reactive Power Compensation Technique

Efficiency is critical in three-phase high-power wireless power transfer (WPT) systems, and the balance of the resonant points for each phase directly impacts efficiency. In this paper, we discuss an effective reactive power compensation (RPC) technique for adjusting the resonant compensation capacitance parameter to correct any unbalanced resonant points in each phase caused by coil misalignment, gap variations, and transmitter (Tx)/receiver (Rx) coil geometry natural tolerance. Experimental results demonstrate that the system is capable of transferring 11kW over a distance of 180 to 250 mm. By improving the system, a significant improvement in power transfer efficiency (PTE) can be achieved, with up to a 0.6% (74 W power saving) increase observed under properly aligned coils. Additionally, the optimized system can still achieve an efficiency improvement of up to 1.59% (205 W power saving), even when there is a 100 cm misalignment between Tx and Rx coils.