Determining the Frequency for Load-Independent Output Current in Three-Coil Wireless Power Transfer System

Energies

Longzhao Sun¹  Houjun Tang²  Yingyi Zhang² 

[1] Department of Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China;

关键词: three-coil;    wireless power transfer (WPT);    frequency;    load-independent output current;   

DOI  :  10.3390/en8099719

来源: mdpi

【 摘 要 】

Conditions for load-independent output voltage or current in two-coil wireless power transfer (WPT) systems have been studied. However, analysis of load-independent output current in three-coil WPT system is still lacking in previous studies. This paper investigates the output current characteristics of a three-coil WPT system against load variations, and determines the operating frequency to achieve a constant output current. First, a three-coil WPT system is modeled by circuit theory, and the analytical expression of the root-mean-square of the output current is derived. By substituting the coupling coefficients, the quality factor, and the resonant frequency of each coil, we propose a method of calculating the frequency for load-independent output current in a three-coil WPT system, which indicates that there are two frequencies that can achieve load-independent output current. Experiments are conducted to validate these analytical results.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.