A Simple Resonant Frequency Tracking Technique for LLC Resonant Converters

Poonahela I., Bayhan S., Abu-Rub H.

6th IEEE INTERNATIONAL CONFERENCE on RENEWABLE ENERGY RESEARCH and APPLICATIONS (ICRERA 2017), California, United States Of America, 5 - 08 November 2017, pp.296-299 identifier identifier

  • Publication Type: Conference Paper / Full Text
  • Volume:
  • Doi Number: 10.1109/distra.2017.8191282
  • City: California
  • Country: United States Of America
  • Page Numbers: pp.296-299
  • Keywords: resonant converter, digital control, DC/DC converter
  • Gazi University Affiliated: No


A LLC resonant converter (LLC-RC) has been widely used in DC/DC converters for the benefits of high efficiency and high power density. The efficiency of a LLC resonant converter is greatly dependent on the switching frequency. In order to achieve higher efficiency, the switching frequency should be equal to the resonant frequency. This paper presents a novel resonant frequency tracking technique for LLC resonant converters (LLC-RC) based on the detection of zero current duration on the secondary side of the converter. The LLC-RC is controlled by the proposed technique to achieve resonant frequency tracking automatically under the various operating condition. To verify the control technique, a 5 kW LLC-RC was designed and tested through a Matlab/Simulink environment.