Modified LCC Compensation and Magnetic Integration for Inductive Power Transfer

An LCC–LCC compensated inductive power transfer (IPT) system has been widely used for the mid- or high-power applications. When dual active bridges (DABs) are used, the famous triple phase shift (TPS) modulation cannot maximize the coupler efficiency when considering the zero-voltage switching (ZVS). A modified LCC compensation is proposed by replacing the input inductor with a transformer. It is able to maintain the benefits of original compensation and dramatically extend the ZVS range, which effectively addresses the conflict between tank efficiency and ZVS. To have a low-profile design, a planar transformer is proposed to be integrated with the coupler, and the winding turn number is used for circuit parameter design. Finally, a 100-W prototype system is implemented based on the modified compensation and magnetic integration solution. In a wide loading and coupling range, the achieved efficiency would be stable within [91.0%, 93.4%]. Compared with the original system, the efficiency improvement at light load condition is 3.7%.