A Simultaneous Wireless Power and Data Transmission Method for Multi-Output WPT Systems: Analysis, Design, and Experimental Verification

Multiple power outputs are necessary in applications such as isolated gate drivers for multilevel converters or DC motor drive. Meanwhile, efficient and reliable data transfer is also essential to achieve satisfactory control performance. In this letter, a simultaneous power and data transmission method is proposed for multi-output wireless power transfer (WPT) systems. An intermediate unit, formed by two unipolar coils with ferrite cores and an aluminum plate in between for mutual coupling enhancement and coupling area shaping, not only can transfer power to adjacent units but also supply power to local loads. Hence, multiple outputs can be achieved. Then, bipolar coils, placed in overlap with the same-side power transfer coils to form a compact and symmetrical structure, are used to transfer data. Such data transfer coils are naturally decoupled with the power transfer coils, leading to a straightforward design of the data processing circuit. Besides, data can be transferred between adjacent circuit units, which facilitates the monitoring and control of all outputs. The feasibility of the proposed coupling structure and the parallel transmission of power and data are verified on a laboratory prototype with two output voltages, and the transfer distance is 20mm while the output power is 180W. The system efficiency reaches 90%, and the data transfer rate is 19.2kb/s.