An Enhanced Quasi-CC Output Model of LCC-P Compensated Inductive-Power-Transfer Converters

It has been explored by current research that the inductor–capacitor–capacitor–parallel (LCC-P) compensated inductive-power-transfer (IPT) converters can achieve constant-current (CC) outputs. However, the CC output model is derived by fundamental-harmonic-analysis (FHA) in a frequency domain, which is not enough accurate to express the output current because the high-frequency current flowing into the rectifier is a discontinuous partial-sine waveform. In this letter, an enhanced-fundamental-harmonic-analysis (EFHA) of LCC-P-compensated IPT system is first proposed to accurately derive the output current model based on the steady-state operating waveforms in a time domain. Under our proposed EFHA, the derivation results show that the output current of LCC-P compensated IPT converters would degrade with the load resistance, and only quasi-CC output can be achieved within a certain load range. The proposed EFHA can be used to design LCC-P compensated IPT system to achieve a quasi-CC output to satisfy the charging requirements, otherwise, the accuracy of charging current and charging speed would be deteriorated with FHA. Both simulation and experiment results are presented to validate the accuracy of EFHA, which show good agreements with the theoretical analysis.