Harmonic Inclusion and Accurate Modeling and Performance Analysis of the IPT Topologies Under Varying Operating Conditions

The fundamental harmonic approximation (FHA) is generally used to design and model inductive power transfer (IPT) circuits. However, with coil misalignments, at light load or the rectifier's discontinuous conduction mode (DCM), the IPT circuit must handle higher harmonic content. Moreover, topologies like LCL and LCC have high harmonics at the inverter output and rectifier input side, even during regular operation. The existing two-port network-based harmonic modeling assumes quasi-square rectifier input voltage for the LCC-LCC topology in DCM condition, thereby leading to significant error. In this article, the rectifier input voltage of LCC-LCC topology (capacitive filter at load) and the rectifier input current of series-parallel (S-P) topology (inductive filter at load) are modified and improved for the DCM mode. Hence, by including the modified expression, accurate results in extreme conditions, high coupling, light load, and DCM scenarios are achieved. The proposed technique models the output port as a voltage/current source instead of approximating it to be resistive. Furthermore, the proposed study equally applies to continuous conduction mode and DCM conditions for the rectifier. A comparison using the FHA-based analysis, proposed harmonic modeling and simulation is carried out, and experimental validation is done for S-P and LCC-LCC topologies.