Fast Hardware Approach to Determining Mutual Coupling of Series-Series-Compensated Wireless Power Transfer Systems with Active Rectifiers

Maximum energy efficiency tracking of series-series-compensated wireless power transfer systems with active rectifiers require the information of mutual coupling coefficient or correlated variables, which are conventionally monitored based on the feedback signals from the receivers to the transmitters via a wireless communication system. In this article, a very fast hardware-based front-end monitoring strategy is proposed to determine the mutual coupling coefficient of the system within typically 62 ms without any wireless communication system. Compared to existing mathematical model-based methods, the proposed strategy is much faster and more cost-effective by using fewer sensors and simpler equations. The proposed method can therefore be implemented in low-cost digital controllers. Importantly, the parameter values of the transmitter and receiver resonators are not required by the proposed method. Both simulation and experimental results are included to validate the high accuracy and fast speed of the proposed monitoring strategy to monitor the coupling coefficient. Comparative results among the proposed and existing monitoring strategies are also presented.