A Load-Independent LCC-Compensated Wireless Power Transfer System for Multiple Loads With a Compact Coupler Design

This article proposes a novel wireless power transfer (WPT) system for multiple loads. Multiple coils are used as power repeaters to enhance the power transfer capability over a long distance and each power repeater corresponds to a load. The inductor-capacitor-capacitor (LCC) compensation method is used for each repeater coil in the system, which ensures load-independent currents flowing through the loads. Thus, flexible power control can be achieved for all the loads without affecting each other. In order to save space, the compensation coil is integrated with the repeater coil to realize a compact design. Bipolar coils are used for both the repeater coil and compensation coil. The undesirable coupling coefficient between the repeater coil and its compensation coil can be eliminated by putting them perpendicularly. The compensation coil is not only used to achieve resonant condition for the system, but also transfers energy to the next repeater coil via the magnetic coupling between them. The operational principle has been explained in detail. An experiment platform with six loads has been built and the experimental results are provided to validate the effectiveness of the proposed WPT repeater system. The maximum efficiency can reach 86.6%.