Output voltage control for series-series compensated wireless power transfer system without direct feedback from measurement or communication

This paper proposes a primary side control for series-series compensated wireless power transfer system. By eliminating the need for a communication link for signal feedback, the control method not only reduces volume and cost of the system, but also improves a dynamic response. This controller only requires the information of the primary side voltage and current to identify the load resistance and the mutual inductances which are essential parameters to estimate the output voltage. To regulate the output voltage, PI controller is used to adjust the switching duty cycle of a full-bridge inverter. The proposed control concept is verified by experimental results. For experiments, the laboratory prototype is designed to achieve 50-W and achieves 89% efficiency at the rated condition.