Comparative Study on Multi-Phase Dynamic Wireless Power Transfer Systems

Dynamic wireless power transfer systems (DWPTSs) improve the mileage and reduce the battery weight of electric vehicles (EVs). Generally, DWPTSs use a 3-phase transmitting coil structure to wirelessly charge moving EVs at a constant rate, but this 3-phase coil structure has not been compared with other possible multi-phase coil structures. Therefore, this paper investigates the suitability of possible and non-conventional multi-phase distributed coil structures for DWPTSs, which are compatible with existing EV static wireless charging standards. The principle of travelling waves is utilized to analyze the continuous and constant power profiles produced by multi-phase distributed coil structures. The output power levels and fluctuations, costs, and electro-magnetic interference (EMI) of multi-phase systems are compared, and the results are presented with key findings highlighted.