Balanced Inverse-Coupled LCC Compensation in IPT Systems With an Integrated Coupler

The magnetic integration method in inductive power transfer (IPT) systems decreases cost and increases power density. In this article, a balanced inverse-coupled inductor-capacitor-capacitor (LCC) compensated system is proposed. A pair of quadruple coils are embedded into the center of main square coils to act like compensation inductors. The inverse-coupled connection of compensation coils is used to construct an additional coupling channel with negative polarity. The analysis shows that the negative additional coupling channel can reduce coil currents and improve system efficiency. The balanced parameter design is extended to this inverse-coupled LCC compensation, aiming to achieve unity power factor, a wide load range, and high misalignment tolerance. Experimental verifications and comparisons are carried out based on a 2.1 kW system. Compared to the no integration scheme, the proposed inverse-coupled system has efficiency improvement within 125–305 mm
z
-axis misalignment and 0–150 mm
x
-axis misalignment. At the rated power and fully aligned condition, the proposed system has 25.6% lower coil currents and 1.3% higher efficiency. The maximum dc–dc efficiency reaches 96.5%.