Structural Decoupling of an Integrated Magnetic Coupler for Wireless Power Transfer

Magnetic integration couplers offer many advantages in wireless power transfer (WPT) system design, but additional coupling will lead to some drawbacks. This paper proposes a new magnetic integration scheme for an LCC–LCC compensation network in WPT systems. First, separate mutual inductance equivalent models are established for each type of additional coupling between the transmitting and receiving coils and the compensation coils. The effects of these additional couplings on the power-transfer characteristics are then analyzed. Second, finite element simulations are conducted to evaluate the decoupling performance of three magnetic integration schemes under aligned and misaligned conditions. The scheme employing DD-type transmitting and receiving coils arranged orthogonally with double-layer DD-type compensation coils demonstrates superior decoupling capability. Third, an integrated magnetic coupling mechanism is fabricated, and the coupling coefficients are measured under aligned and misaligned conditions. The proposed integration scheme effectively decouples multiple additional couplings, achieving about a 65% reduction in the compensation-coil additional coupling coefficient. Finally, an experimental prototype is implemented. The experimental results show a maximum transfer efficiency of 95.2%.