Design of Load-Independent CC and CV Mode Inductive Power Transfer System Based on Reconfigurable S/SP Compensation

In this article, a novel secondary reconfigurable S/SP (R-S/SP) compensation network and parameter design method are proposed. The proposed compensation network can reconfigure the S/SP circuits by switching to implement load-independent constant-current mode (CCM) and constant-voltage mode (CVM), respectively, without the need for communication. The derivation of a generalized design methodology is given in detail based on the two-port network transfer matrix approach. By adjusting the parameter factors, the R-S/SP topology can maintain both the zero-voltage switch (ZVS) characteristic in the Class-D inverter’s wide load range and the stability of the voltage and current gains under misalignment tolerance. Also, the gains are tunable in this topology. Finally, a 0.6 MHz, 108 W inductive power transfer (IPT) prototype is developed with a CVM output of 72 V and a CCM output of 1.5 A. The experimental results show that load-independent switching of CCM and CVM can be implemented. The system can operate at a lateral offset of ±21%, with CCM gain fluctuations of less than 6.8% and CVM gain fluctuations of less than 9.9% over the full impedance range. The ZVS is realized throughout the process, and the system efficiency reaches 91.1% at maximum power.