An Inverter Topology for MultiTransmitter Wireless Power Transfer Systems

This paper presents an inverter topology for a static wireless power transfer (SWPT) system that is intended to reduce the component counts and complexity of the conventional excitation circuit for multiple transmitter coils. The proposed inverter topology requires only (n+1) power switches, where “n” is the number of transmitter coils. The currents in the transmitter coils can be independently controlled. The output voltage is regulated through the transmitter-side control by adjusting the duty cycle of the inverter switches. A detection method of the receiver coil position is developed by comparing the transmitter currents to the predetermined transmitter coil patterns. The proposed detection method helps decide the proper transmitter selection, which improves the transfer efficiency throughout the operation. An experimental study is performed on the created 500-watt WPT multi-coil system. As the receiver coil is placed in the designated area, the proper transmitter coil pattern can be automatically selected and energized. The output voltage can be regulated to the desired values throughout the operation, regardless of the load condition.