High-Efficiency Bilateral S–SP Compensated Multiload IPT System With Constant-Voltage Outputs

Abstract

In this article, we propose a bilaterally transmitted domino-type multiload inductive power transfer (IPT) system for constant-voltage (CV) outputs, low voltage attenuation, and high efficiency. There are three major contributions. First, the series–series/parallel (S–SP) topology is developed to design the multiload IPT system, which can realize the load-independent CV outputs without using compensation inductors, enabling a compact IPT system. Second, a bilateral IPT structure is proposed with two parallel power transfer routes to mitigate the practical output voltage attenuation issue, resulting in a better CV property. Third, system efficiency is improved by the proposed bilateral IPT structure. With the bilateral S–SP compensated multiload IPT design, the output voltage attenuation analysis and system efficiency are investigated considering parasitic resistances. A 70 W six-load bilateral IPT prototype is implemented and compared with the unilateral counterpart. With <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</i> = 0.26 and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Q</i> = 300, the proposed bilateral IPT system validates an improved CV output with a small attenuation rate of 10.22%, which is much lower than the unilateral one. The maximum efficiency achieves 90.39%, showing 5.17% higher than the unilateral IPT system in the identical load condition.