access icon openaccess Short-circuit protection of LLC resonant converter using voltages across resonant tank elements

This is an open access article published by the IET under the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0/)
Received 30/04/2015, Accepted 30/04/2015, Published 11/05/2015

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.

Inspec keywords: power convertors; short-circuit currents; electric current measurement; current transformers

Other keywords: power 1600 W; shunt resistor; resonant tank; LLC resonant converter; capacitor; short-circuit protection; resonant tank elements; inductor; LLC converter design; current transformer

Subjects: Inductors and transformers; Power electronics, supply and supervisory circuits

References

    1. 1)
    2. 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. 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. 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. 5)
    6. 6)
    7. 7)
    8. 8)
http://iet.metastore.ingenta.com/content/journals/10.1049/joe.2015.0079
Loading

Related content

content/journals/10.1049/joe.2015.0079
pub_keyword,iet_inspecKeyword,pub_concept
6
6
Loading