Constant Current Charging and Maximum System Efficiency Tracking for Wireless Charging Systems Employing Dual-Side Control
Journal article, 2020

Wireless power transfer (WPT) systems have attracted much attention because of their safety, convenience, and environmental friendliness. For wireless supercapacitor charging, the system efficiency and charging current are highly dependent on the load that varies over a wide range. In this article, a simultaneous maximum system efficiency (MSE) tracking and constant current (CC) charging control scheme for a supercapacitor is proposed. For CC charging, a double-sided LCC topology is chosen due to its characteristic of providing a load-independent output current. Furthermore, the impact of the coil internal resistance on the system characteristics (especially the charging current) is investigated, so a semiactive rectifier is introduced on the secondary side to achieve accurate CC charging and improve the system robustness. Based on the variable-step perturbation and observation algorithm, the MSE is tracked by searching for the minimum system input dc current using a primary-side buck converter on the premise that the charging current reaches its target value. The abovementioned two control loops are independent, and mutual communication is unnecessary when they cooperate; thus, the system is simplified. The simulation and experimental results show great consistency with the theoretical analysis. The experimental system maintains the MSE of 86% during charging the supercapacitor from 20 to 50 V with 2 A.

Constant current (CC) charging




Immune system


maximum system efficiency (MSE) tracking

Buck converters


variable-step perturbation and observation (VS-P&O) algorithm

wireless power transfer (WPT)


Kai Song

Harbin Institute of Technology

Ruizhi Wei

Harbin Institute of Technology

Guang Yang

Harbin Institute of Technology

Hang Zhang

Harbin Institute of Technology

Zhenjie Li

Harbin Institute of Technology

Xiaoliang Huang

Chalmers, Electrical Engineering, Electric Power Engineering

Jinhai Jiang

Harbin Institute of Technology

Chunbo Zhu

Harbin Institute of Technology

Zhijiang Du

Harbin Institute of Technology

IEEE Transactions on Industry Applications

0093-9994 (ISSN) 1939-9367 (eISSN)

Vol. 56 1 622-634 8844122

Subject Categories

Embedded Systems

Control Engineering

Other Electrical Engineering, Electronic Engineering, Information Engineering



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4/5/2022 6