A multi‐tap‐receiver based wireless power transfer system with multiple independent outputs and reduced wire length

Abstract

Multiple independent outputs are highly desirable to power the different ports in some power distribution wireless power transfer (WPT) systems. This paper develops a WPT system with one transmitter coil and one multi‐tap‐receiver coil to generate multiple independent output voltages. The systems with dual‐tap‐receiver, three‐tap‐receiver, and multiple‐tap‐receiver are analyzed in theory. Because the sub‐windings of the multi‐tap‐receiver can be reused in positive series, the wire length of the receiver (WLR) is reduced compared to the system with multi‐independent receivers. For instance, a multiple outputs system needs N voltage levels (v1, v2, …, vN) while the receiver has N sub‐windings (LS1, LS2, …, LSN), then the voltage level vi (1 ≤ i ≤ N) is powered by sub‐windings LS1, LS2, …, LSi. Hence, the highest voltage level is fed with the entire charge included in the whole receiver, and a part of the sub‐windings supplies low‐voltage levels. The proposed system reduces WLR by more than 32.77% while v2/v1 is 2:1, and under the condition that v3/v2/v1 is 3:2:1, the saved WLR is higher than 75.73%. Besides, an 880‐W prototype with a dual‐tap receiver is built. The experimental results verify that the dual output voltages are load‐independent and non‐interfering. The efficiency is higher than 93.259%.