Comparison Study of Inductive Coupling and Magnetic Resonant Coupling Method for Wireless Power Transmission of Electric Vehicles

Wireless power transfer via magnetic resonant coupling method and inductive coupling method has open new possibility to Electric Vehicle (EV) system. The efficiency depends on the factors such as coupling coefficient and quality factor. Therefore, it becomes a crucial factor to estimate such parameters for better efficiency. This paper presents the comparison between inductive coupling method and magnetic resonant coupling method of wireless charging system based on these parameters. It is estimated that quality factor needed for magnetic resonant coupling wireless charging method of electric vehicles is approximately 20 more than that needed for inductive coupling method at same efficiency within a range of coupling coefficient. Also, the coupling coefficient needed for magnetic resonant coupling wireless charging method of electric vehicles is approximately 0.01 more than that needed for inductive coupling method at same efficiency within a range of quality factor.