Efficiency Improvement of LCC-S Based IPT System by Detuning Design of the Secondary Side to Gain Unity Power Factor

To improve the power transfer efficiency (PTE) of the inductive power transfer (IPT) system based on LCC-S compensation network, a detuning design method of the secondary side is proposed in this article. First, time-domain analysis is used to model IPT system with a tuned and detuned secondary side, respectively. It was found that the reactive components brought by the rectifier can be compensated when the secondary side is detuned to a specific extent, thus gaining a unity power factor (UPF) in the secondary side. Then, design methods for the LCC network in the primary side both for fixed and variable load are proposed. Finally, simulations and experiments are conducted to verify the proposed modeling and designing method, with which the PTE can be improved in condition of coil misalignment and load variation, especially when the rectifier is in discontinuous conduction mode.