Design Procedure of Load-Independent Class-E WPT Systems and Its Application in Robot Arm

This article presents a design procedure for wireless power transfer (WPT) systems with the load-independent class-E inverter family. The design procedure guarantees that the WPT system will achieve constant output and soft switching in response to load variations without particular control, which can apply not only single-hop single-output but also multihop multioutput WPT system designs. It is analytically explained that a WPT-system output type is determined by properly selecting the inverter, rectifier, and coupling resonant structure. As a concrete design example, we designed the three-hop three-output WPT system for installation into a robot arm. Experimental results exemplified the validity and usefulness of the established procedure.