Free-Positioning Wireless Power Transfer System Based on One-to-Multiple Topology

The wireless power transfer (WPT) system is an interesting alternative for charging electric vehicles and has a broad prospect in public transport applications. In order to obtain optimal power transfer, the existing WPT systems often require perfect alignment between the primary and secondary coils, which can hardly be met in real applications. To relieve this problem and achieve the goal of free positioning, a one-to-multiple WPT topology being able to improve the misalignment tolerance at the secondary side is proposed in this letter. Based on circuit analysis and MATLAB simulation, a mixed mode is proposed to obtain a steady power transfer with horizontal misalignment. To verify the proposed topology, a one-to-two WPT system with a three winding transformer is developed in this letter, showing that proposed topology with the mixed mode can significantly increase the positioning adaptability.