Research on Three-Phase Hybrid Compensation WPT System With High Misalignment Tolerance and Its ZVS Control Strategy

A three-phase double-sided series and LCC hybrid compensation converter is proposed in this article to achieve high misalignment tolerance and power capability of the wireless power transfer (WPT) system. To obtain excellent performances of the
x
,
y
,
z
, and
xy
misalignments, a three-phase coupler consisting of adjacent placement of double-D and rectangular coils which have no same-side cross couplings within and among each phase is employed in the proposed converter, it can obtain approximately constant output current with misalignments and load variations. Furthermore, the three-phase imbalanced load characteristics caused by
xy
misalignment with double-sided cross couplings in adjacent phases are analyzed in detail, and the ZVS control strategy based on three-phase four-leg converter is proposed to ensure the high system efficiency in this case. Finally, a 10 kW prototype with three-phase coupler is built to verify the viability of the proposed three-phase hybrid compensation WPT system. The experimental results show that the proposed converter achieves ZVS in all misalignment directions and the system efficiency achieves 95.13% with fully aligned. The maximum output current fluctuation factor is 10.35% and 1.97% within the designed ranges of misalignments and load variations, respectively.