Dynamic Modeling and Control Design Based on Singular Perturbation Theory for High-Order Wireless Power Transfer System

Dynamic performance analysis and controller design of wireless power transfer (WPT) systems have always been tough problems because the existing dynamic models of WPT systems have disadvantages, such as high order, incompleteness, and lack of intuition. In this article, a dynamic modeling method based on a singular perturbation theory for a high-order WPT system with a Cuk-based bridgeless rectifier at the receiving side is proposed, which overcomes the disadvantages of the dynamic models mentioned above. In terms of time-scale separation characteristics brought by singular perturbation, a reduced-order model can be derived from the original high-order WPT system model. The proposed model is able to completely present the dynamic behaviors of the whole WPT system precisely. Also, a closed-loop control design method based on the reduced-order model is presented, which greatly simplifies the design process. The experimental results show the great effectiveness of the proposed model for transient state observation, and the output voltage or current of the closed-loop WPT system remains stable despite significant disturbances in load or transfer distance.