Article ID: 24001943
In modular three-phase wireless power transfer (WPT) systems, efficiency is crucial, and the consistency of the resonant frequency in each phase module directly affects efficiency. This paper discusses an effective resonant frequency stabilization (RFS) technique for adjusting the resonant compensation capacitor parameters to correct the unbalanced resonant frequency in each phase caused by coil misalignment or variations in the transmission gap and the natural tolerance of the transmitter (Tx)/receiver (Rx) coil geometry. The method compensates for misalignment tolerance and enhances overall system performance by making these adjustments. To validate the proposed concept, experimental results have been conducted, demonstrating that the system is capable of transferring 11 kW over a distance of 180 to 250 mm. A significant improvement in power transfer efficiency (PTE) can be achieved, up to a 3.10% increase (saving 406.3W of power) under coil alignment. Additionally, even with a 100 mm misalignment between Tx/Rx coils, the optimized system can still achieve an efficiency improvement of up to 4.09% (saving 599.7W of power). Finally, the main contribution of this paper is introducing a modular three-phase WPT system design method, offering an effective solution for stabilizing resonant frequencies compared to alternative topologies, and is well-suited for commercial purposes.
