A Switchable-LCL-Circuit-Based IPT System With High Efficiency for Reefer Containers

To get rid of plug-in/out actions for automatic wharves, a switchable-LCL-circuit (SLC) based inductive power transfer system is proposed to improve efficiency for reefer container wireless charging. As we knew, the power requirement of a reefer container only hits a few operation points, and each operation point is in corresponding to an individual resistance point (IRP). Therefore, the system efficiency can be improved by altering the IRPs into the optimal load resistance (OLR). The idea of this letter is to use the SLC to create multiple efficiency-load curves, then to regulate the peak points of the curves approaching the IRPs by reconfiguring the compensation parameters. Finally, a prototype was built to validate the performance of the proposed approach. The experimental results show that with the SLC, both the IRPs 20 and 160 Ω can be transformed into the OLR 55 Ω; the proposed system can gain the system efficiency >92.4% at the IRPs (20 Ω, 259.2 W) and (160 Ω, 32.4 W).