This is an open access article published by the IET under the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0/)
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.
References
-
-
1)
-
2. Kurs, A., Karalis, A., Moffatt, R., Joannopoulos, J.D., Fisher, P., Soljacic, M.: ‘Wireless power transfer via strongly coupled magnetic resonances’, Science, 2007, 317, pp. 83–86 (doi: 10.1126/science.1143254).
-
2)
-
6. Kusaka, K., Itoh, J.: ‘Experimental verification of rectifiers with SiC/GaN for wireless power transfer using a magnetic resonance coupling’. Proc. 2011 IEEE Ninth Int. Conf. Power Electronics and Drive Systems, 2011, pp. 1094–1099, .
-
3)
-
5. Chen, W., Chinga, R.A., Yoshida, S., Lin, J., Chen, C., Lo, W.: ‘A 25.6 W 13.56 MHz wireless power transfer system with a 94% efficiency GaN Class-E power amplifier’. Proc. 2012 IEEE MTT-S Microwave Symp., 2012, pp. 1–3, .
-
4)
-
4. Calder, R.J., Lee, S., Lorenz, R.D.: ‘Efficient, MHz frequency, resonant converter for sub-meter (30 cm) distance wireless power transfer’. Proc. 2013 IEEE Energy Conversion Congress and Exposition, 2013, pp. 1917–1924, .
-
5)
-
3. Shoki, H.: ‘Issues and initiatives for practical deployment of wireless power transfer technologies in Japan’. Proc. IEEE, 2013, vol. 101, pp. 1312–1320, .
-
6)
-
A. Kurs ,
A. Karalis ,
R. Moffatt ,
J.D. Joannopoulos ,
P. Fisher ,
M. Soljacic
.
Wireless power transfer via strongly coupled magnetic resonance.
Science
,
6 ,
83 -
86
-
7)
-
2. Tseng, R., Novak, B., Shevde, S., Grajski, K.A.: ‘Introduction to the alliance for wireless power loosely-coupled wireless power transfer system specification version 1.0’. Proc. 2013 IEEE Wireless Power Transfer Conf., 2013, pp. 79–83, .
http://iet.metastore.ingenta.com/content/journals/10.1049/joe.2014.0245
Related content
content/journals/10.1049/joe.2014.0245
pub_keyword,iet_inspecKeyword,pub_concept
6
6