Dual-Side Asymmetrical Voltage-Cancelation Control for Bidirectional Inductive Power Transfer Systems

Bidirectional inductive power transfer (BIPT) systems for electric vehicles allow power exchange between grid and vehicle. To achieve high transfer efficiency under a wide range of transmission power, this article proposes a dual-side asymmetrical voltage-cancelation (AVC) control technique. With the proposed dual-side AVC control, the adjustment of the fundamental component amplitude of the excitation voltage, the maintenance of a large phase angle between excitation voltages as well as zero-voltage switching (ZVS) of the power switches, and the optimization of the resonant tank power transfer efficiency can be achieved simultaneously. The basic characteristics and the conditions for maximum transfer efficiency of the resonant tank are derived. The control scheme for the overall system including the control of the primary-side and secondary-side full bridges is proposed, which considers both efficiency optimization and ZVS operation of all switches. The ZVS range of the proposed dual-side AVC control technique is presented. Experiments are performed with dual-phase-shift, triple-phase-shift, and the proposed dual-side AVC control technique, which show that the BIPT system with the proposed dual-side AVC control technique achieves a higher efficiency over the others in a wide range of transmission power.