An LCL-Based SS Compensated WPT Converter With Wide ZVS Range and Integrated Coil Structure

In this article, a zero-voltage switching (ZVS) series-series compensated wireless power transfer (WPT) converter with phase shift modulation is proposed, which can realize output current regulation over wide range. In the proposed WPT converter, an auxiliary LCL resonant network is connected between two midpoints of the H-bridge legs of inverter to provide the peak current for ZVS operation during the dead time, with low rms current to decrease the conduction losses. To reduce the volume of the auxiliary network, an integrated coil structure is applied and the magnetic saturation is avoided due to the orthogonal coil currents. Time-domain analysis and ZVS operation of the proposed WPT converter are performed. Design and optimization of the LCL network are performed. Experimental results of a prototype with 8-20 A adjustable output current confirm the feasibility of the proposed method.