An Efficient Variable Frequency Control Method for S/S-compensated Wireless Power Transfer Systems

Post-stage DC-DC converters are generally employed In wireless power transfer (WPT) systems because of varied coupling coefficients. To remove the DC-DC converter and achieve high power transfer efficiency of a WPT system working under misalignment conditions, this paper proposes a variable frequency control (VFC) strategy. The switches of the primary inverter achieve zero voltage switching (ZVS) throughout the operation in the proposed WPT system, which improves the system efficiency. Series-series (S/S) compensation topology and planar square coupler are employed to simplify the control model and improve the misalignment tolerance. Misalignment tolerance of the WPT system in all directions was verified by simulation.