Control of a Three-Phase Inductive Power Transfer System Based on DD²Q Coil Topology

Abstract:
Problem of inter-phase coupling between the different phases of a poly-phase inductive power transfer (IPT) system is present in all of such systems when they operate under non-aligned conditions. This leads to uneven load sharing between the phases and to the increased reactive power circulating in the system. In this paper we propose a control strategy for a compact three-phase IPT charger based on the DD(exp2)Q magnetic coupler topology that ensures equal power distribution between the phases on the secondary side and equal current stress of the primary semiconductors, under misalignment conditions. The proposed control strategy has been tested on the laboratory prototype, for power of 6.83kW, with 86.1% system efficiency, achieving power transfer increase of 20.5%, achieving and showing efficiency increase of 1.6% comparing to the case with no control strategy applied.