Dual-PWM Control of Inductive Power Transfer Systems for High Efficiency Over Wide Load Ranges

The efficiency of inductive power transfer (IPT) systems is strongly dependent on the load. To achieve high transfer efficiency across a wide range of loads, this paper proposes a dual-PWM control strategy, which enables zero voltage switching (ZVS) for all the power switches and optimization of the resonant tank power transfer efficiency (low reactive power) simultaneously. We present the ZVS range of the proposed dual-PWM control strategy and experimentally compare the proposed approach to dual-phase-shift (DPS) control and triple-phase-shift (TPS) control using a 600 W prototype and show that the proposed approach achieves higher efficiency than others across a wide load range.