Optimization Method for Multi-Channel Wireless Power Transfer Based on Coil Splitting

The wireless power transfer (WPT) system is widely used for its convenience. However, the constant output cannot be easily satisfied in traditional Series-Series (SS) system because of its weak misalignment tolerance. This paper proposes a design method for an output-parallel Series-Series (SS) WPT system based on a designed splitting coil coupler. The method for optimizing output performance is also presented. Besides, by designing splitting coils and specific parameters, the performance of misalignment tolerance of multi-channel coils is improved, and the zero-voltage switch (ZVS) can be always realized in the given misalignment range. Finally, A 3.3kW splitting coil WPT system prototype is built, achieving nearly constant output in the given misalignment range, and the measured transfer efficiency decrease caused by misalignment is only 2.8%.