Simultaneous control of efficiency and power in a WPT system using position information between transmission and reception coils

Wireless power transfer (WPT) system based on magnetic resonance coupling method is expected to be the next generation wireless power transfer system due to excellent transmission characteristics. One of the problems with WPT system is the limited power and low efficiency, which depends on the circuit parameters and the positioning of the coils. In this paper, to control efficiency and power simultaneously by compensating the position between transmission and reception coils and using DC-DC converter is proposed. First, it is explained that efficiency and power can be controlled by coupling ratio manipulation because of coils position control and by impedance conversion using buck converter control. Then, the simultaneous control system is designed and its feasibility is confirmed by simulation.