A 99%-efficiency GaN converter for 6.78 MHz magnetic resonant wireless power transfer system

The Journal of Engineering

Yuki Ito¹  Yoshiyuki Akuzawa¹  Toshihiro Ezoe¹  Kiyohide Sakai¹ 

[1] Kamakura Office, Mitsubishi Electric Engineering Co. Ltd, 730 Kamimachiya, Kamakura, Kanagawa 247-0065, Japan

关键词: size 150 mm;    gate–source capacitance;    efficiency 82.8 percent;    size 40 mm;    drain efficiency;    power 33 W;    efficiency 97.7 percent;    magnetic resonant coils;    power 25 W;    negative-bias gate driver circuit;    Si;    frequency 6.78 MHz;    magnetic resonant wireless power transfer system;    depletion mode GaN high-electron-mobility transistor;    efficiency 98.8 percent;    gallium-nitride Class-E converter;    GaN;    depletion mode GaN HEMT;    GaN Class-E converter;    Si Schottky barrier diodes;    full-bridge rectifier;   

DOI  :  10.1049/joe.2014.0245

学科分类：工程和技术（综合）

来源: IET

【 摘 要 】

The authors developed a high-efficiency gallium-nitride (GaN) Class-E converter for a 6.78 MHz magnetic resonant wireless power transfer system. A negative-bias gate driver circuit made it possible to use a depletion mode GaN high-electron-mobility transistor (HEMT), and simplified the converter circuit. As the depletion mode GaN HEMT with very small gate–source capacitance provided almost ideal zero-voltage switching, the authors attained a drain efficiency of 98.8% and a total efficiency of 97.7%, including power consumption of a gate driver circuit, at a power output of 33 W. In addition, the authors demonstrated a 6.78 MHz magnetic resonant wireless power transfer system that consisted of the GaN Class-E converter, a pair of magnetic resonant coils 150 mm in diameter with an air-gap distance of 40 mm, and a full-bridge rectifier using Si Schottky barrier diodes. The system achieved a dc–dc efficiency of 82.8% at a power output of 25 W. The efficiencies of coil coupling and the rectifier were estimated to be ∼ 94 and 90%, respectively.

【 授权许可】

CC BY