Discrete Modeling of Passive Rectifiers in LCL Tuned Inductive Power Transfer Receivers

This article presents a new method of analyzing the performance of the secondary side of an LCL-tuned secondary in an inductive power transfer (IPT) system using a passive rectifier. Traditional methods of analyzing such systems simplify the dc load into an equivalent ac load. This approximation skews the phase shifts between the primary and secondary currents and introduces errors in the design stage of the system. The proposed method uses a lookup table (LUT) to characterize the performance of the LCL-tuned secondary network. The results are presented and validated at three different power levels (48, 9, and 4 kW). The LUT closely agrees with the measured output powers, phase angles, and coil currents. A sensitivity analysis also shows that it can reduce errors in the simulation by taking practical component variations into account. As such, the proposed LUT characterization method is a valuable tool to quickly determine how an IPT system's design impacts the secondary side's performance in an LCL-tuned network with a passive rectifier for IPT systems.