Dynamic efficiency tracking controller for reconfigurable four-coil wireless power transfer system

This paper presents a dynamic efficiency tracking control strategy for reconfigurable four-coil wireless power transfer (R-WPT) system. The proposed R-WPT system includes an array of drive loops, a transmitter (Tx coil), a receiver (Rx coil), an array of load loops, two relay switch arrays, a rectifier and a control unit. By sensing voltage and/or current from the power source and the load, Tx and Rx side switches are adaptively controlled such that one drive loop out of several drive loops with different diameters is connected to the power source and one load loop out of several load loops with different diameters is connected to the load. Since drive loops and load loops have different sizes, the optimum coupling factor with corresponding drive loop and load loop is adaptively varied and selected, such that the maximum efficiency is achieved at a given distance/misalignment condition. Proof of concept experimental results demonstrate and verify the operation of the system achieving high efficiency.