A Decoupled Power and Data-Parallel Transmission Method With Four-Quadrant Misalignment Tolerance for Wireless Power Transfer Systems

In this letter, a new power and data-parallel transmission method for wireless power transfer (WPT) systems based on a magnetically decoupled coupling structure is proposed. Unipolar coils are used for power transfer, while series-connected perpendicular bipolar coils are used for data transfer. Data transfer coils are placed in overlap with the power transfer coils at both primary side and secondary side, respectively, to form a compact structure. Especially, the side lengths of data transfer coils are intentionally designed to be smaller than the power transfer coils. Thus, in the specific four-quadrant misalignment area, the crosstalk interference between power and data transfer channels can almost be neglected, resulting in a straightforward design of data processing circuit. With the proposed coupling structure, data transfer presents a symmetrical misalignment ability. Moreover, the data transfer channel is utilized to conduct the closed-loop control of output voltage in the WPT system. Thus, in the specific four-quadrant misalignment area, stable power transfer can also be achieved. The feasibility of the proposed power and data-parallel transfer method is verified by a 122-W laboratory prototype. The system efficiency reaches 87% and data transfer rate is 19.2 kb/s. (This letter is accompanied by a video demonstrating the experimental test).