This is an open access article published by the IET under the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0/)
This paper describes two methods for the short-circuit protection of the LLC resonant converter. One of them uses the voltage across the capacitor and the other uses the voltage across the inductor of the resonant tank. These voltages can be processed (integrated or differentiated) to recover the resonant tank current. The two circuits illustrated in the described methods make it possible to develop a robust LLC converter design and to avoid using lossy current measurement elements, such as a shunt resistor or current transformer. The methods also allow measuring resonant tank current without breaking high-current paths and connecting the measuring circuit in parallel with the inductor or capacitor of the resonant tank. Practical implementations of these indirect current measurements have been experimentally tested for the short-circuit protection of the 1600 W LLC converter.
References
-
-
1)
-
4. Xie, X., Zhang, J., Zhao, C., Zhao, Z., Qian, Z.: ‘Analysis and optimization of LLC resonant converter with a novel over-current protection circuit’, IEEE Trans. on Power Electron., 2007, 22, (2), pp. 435–443 (doi: 10.1109/TPEL.2006.889919).
-
2)
-
3. Yang, B., Lee, F.C., Concannon, M.: ‘Over current protection methods for LLC resonant converter’. Applied Power Electronics Conf. and Exposition, 9–13 February 2003, vol. 2, pp. 605–609.
-
3)
-
5. Figge, H., Grote, T., Fröhleke, N., Böcker, J., Schafmeister, F.: ‘Overcurrent protection for the LLC resonant converter with improved hold-up time’. Applied Power Electronics Conf. and Exposition (APEC), 2011, pp. 13–20.
-
4)
-
6. Liu, S., Ren, R., Meng, W., Zheng, X., Zhang, F., Xiao, L.: ‘Short-circuit current control strategy for full-bridge LLC converter’. Energy Conversion Congress and Exposition (ECCE), 2014, pp. 3496–3503.
-
5)
-
2. Liu, R., Batarseh, I., Lee, C.Q.: ‘Comparison of performance characteristics between LLC-type and conventional parallel resonant convertors’, Electron. Lett., 1988, 24, (24), pp. 1510–1511 (doi: 10.1049/el:19881031).
-
6)
-
8. Kim, S.K., Han, H.S., Woo, Y.J., Cho, G.H.: ‘A low-cost high-efficiency CCFL inverter with new capacitive sensing and control’, IEEE Trans. Power Electron., 2006, 21, (5), pp. 1444–1451 (doi: 10.1109/TPEL.2006.880256).
-
7)
-
1. Liu, R., Lee, C.Q.: ‘Analysis and design of LLC-type series resonant convertor’, Electron. Lett., 1988, 24, (24), pp. 1517–1519 (doi: 10.1049/el:19881036).
-
8)
-
7. Sheng, H., Wang, F., Tipton, C.W.: ‘A fault detection and protection scheme for three-level DC-DC converters based on monitoring flying capacitor voltage’, IEEE Trans. Power Electron., 2012, 27, (2), pp. 685–697 (doi: 10.1109/TPEL.2011.2161333).
http://iet.metastore.ingenta.com/content/journals/10.1049/joe.2015.0079
Related content
content/journals/10.1049/joe.2015.0079
pub_keyword,iet_inspecKeyword,pub_concept
6
6