Transferred Power Leveling/Energy Maximization in Dynamic WPT Systems

The paper deals with the design of the compensation network in the wireless power transfer systems (WPTSs) devoted to charging the electric vehicles (EVs) while cruising. An inconvenience of these systems, commonly termed dynamic WPTSs, is the large variation of the power transferred to the EVs due to the correspondingly large change of the mutual coupling between the pickup and the track coils during the EV motion. Many attempts have been done to level such a power by help of multi-element compensation networks. In this paper, a simple one-element compensation topology, namely the series-series one, is considered and the design is aimed at evaluating its power leveling capabilities by a suitable sizing of the track-side compensation capacitor. As an alternative, the objective is pursued of maximizing the transferred energy. Formulation of the analytics for the two objectives is presented and the results obtained on a study case are given. It is shown that the achievement of the two objectives leads for a somewhat different size of the compensation capacitor, depending on the length of the pickup compared to that of the track coils.