A Misalignment-Tolerant Hybrid Coupler for Electric Vehicle IPT Charging Systems

To solve the problems of output voltage and system efficiency sharply decreasing in the case of misalignment for the electric vehicle inductive power transfer (IPT) charging system, a universal hybrid coupler with high misalignment tolerance is proposed. The hybrid coupler consists of a four-coil bipolar (BP) coupler, the T-type network and a compensation capacitor, which effectively achieves high anti-misalignment for any compensation networks. The introduction of the T-type network makes the two overlapping coils in the same side of the BP coupler transmitter de-couple effectively and simplifies the design. Although the two overlapping coils in the receiver side are still coupled with each other, the parameter design only needs to consider the cross-coupling to be small enough, which significantly reduces the design difficulty of the coupler without iteration and repetition. Finally, a 2-kW misalignment-tolerance hybrid IPT system is constructed based on the proposed hybrid IPT coupler. A configurable series-series (SS) and series/inductor-capacitor- capacitor(S/LCC) compensation topologies are used to implement constant current (CC) and constant voltage (CV) load-independent outputs in the face of conditions where the coupling coefficient and load change simultaneously. The experimental results validate the correctness of the theoretical analysis.