Feasibility study of hybrid inductive and capacitive wireless power transfer for future transportation

Due to the inconvenience and safety issues caused by exposed plugs and damaged cables, wireless charging of electric vehicles (EV) has gained popularity. Inductive wireless power transfer has been successfully applied up to 30kW involving the charging of EV batteries. The capacitive wireless power transfer system is new for the EV charging application, but can address the transfer of power across metallic barriers with much less losses. The performance of different compensation topology for each system is compared based on the power transfer ability, complexity, switching frequency, electromagnetic interference tolerance and efficiency. Finally, the possibility of a hybrid topology for improving the power transfer, efficiency and misalignment tolerance is considered from the literature, which can also make the system size more compact by achieving cross resonance between inductive coils and capacitive plates. The review provides a brief account of the recent laboratory prototypes for inductive wireless power transfer (IWPT), capacitive wireless power transfer (CWPT) and hybrid wireless power transfer techniques which can be adopted for wireless EV charging.