Advanced Electric Power Conversion Laboratory

Name: Minfan Fu


School of Info. Science and Tech.

ShanghaiTech University

Room 202C, SIST Building 2

393 Middle Huaxia Road

Pudong, Shanghai 201210

Tel: +86-021-20684455

A journal paper is accepted by IEEE Trans. Ind. Informa.

M. Fu, Z. Tang, and C. Ma*, “ Analysis and Optimized Design of Compensation Capacitors for A Megahertz WPT System Using Full Bridge Rectifier", IEEE Transactions on Industrial Informatics


The spatial freedom of wireless powertransfer (WPT) systems can be improved using a high operating frequency such asseveral megahertz (MHz). In the conventional compensations the load of thecoupling coils is usually assumed to be pure resistive. However, in MHz WPTsystems this assumption is not accurate anymore due to the non-neglectablerectifier input reactance. This paper discusses the impedance characteristicsof the full-bridge rectifier at MHz and their influence under the series-series,parallel-series, series-parallel, and parallel-parallel compensationtopologies. An undesirable non-zero phase (i.e., none unity power factor) isshown to exist at the primary input port, which leads to decreased powertransfer capability. In order to minimize this negative effect, thecompensation capacitors are optimally designed, and the series-series topologyis found to have the smallest phase under load and coupling variations.Finally, an experimental 6.78 MHz system is built up to verify the optimized designof the compensation capacitors. The results show that the average non-zerophase is effectively reduced together with the improved power factor from 0.916to 0.982.