A simple control scheme for improving light-load efficiency in a full-bridge LLC resonant converter

In this paper, a load adaptive phase-shift control is proposed for the full-bridge LLC resonant converter to improve light-load efficiency. The proposed method reduces the effective duty ratio and the magnetizing current. Therefore, the core loss on transformer and the turn-off switching loss on switches are significantly reduced. To confirm the validity of this study, the prototype with 320~400V DC input, 12V/40A DC output is experimented.

[1]  L. Huber,et al.  Methods of Reducing Audible Noise Caused by Magnetic Components in Variable-Frequency-Controlled Switch-Mode Converters , 2011, IEEE Transactions on Power Electronics.

[2]  Paolo Mattavelli,et al.  Digital implementation of driving scheme for synchronous rectification in LLC resonant converter , 2010, 2010 IEEE Energy Conversion Congress and Exposition.

[3]  F.C. Lee,et al.  Power architecture design with improved system efficiency, EMI and power density , 2008, 2008 IEEE Power Electronics Specialists Conference.

[4]  Jae-Hyun Kim,et al.  Light-load efficiency improvement using load adaptive gate driving method , 2013, 2013 IEEE ECCE Asia Downunder.

[5]  Yan-Fei Liu,et al.  A new resonant gate drive circuit with efficient energy recovery and low conduction loss , 2008, 31st Annual Conference of IEEE Industrial Electronics Society, 2005. IECON 2005..

[6]  Sheng Ye,et al.  A New Dual-Channel Resonant Gate Drive Circuit for Low Gate Drive Loss and Low Switching Loss , 2008, IEEE Transactions on Power Electronics.

[7]  J.A. Abu-Qahouq,et al.  Analysis and Design of Voltage Regulator With Adaptive FET Modulation Scheme and Improved Efficiency , 2008, IEEE Transactions on Power Electronics.

[8]  Jianping Ying,et al.  Analysis and Implementation of LLC Burst Mode for Light Load Efficiency Improvement , 2009, 2009 Twenty-Fourth Annual IEEE Applied Power Electronics Conference and Exposition.

[9]  Sheng Ye,et al.  A New Resonant Gate Drive Circuit for Synchronous Buck Converter , 2007, IEEE Transactions on Power Electronics.

[10]  T.H. Lee,et al.  A constant-frequency method for improving light-load efficiency in synchronous buck converters , 2005, IEEE Power Electronics Letters.

[11]  Yan Liang,et al.  Optimal design methodology for LLC resonant converter , 2006, Twenty-First Annual IEEE Applied Power Electronics Conference and Exposition, 2006. APEC '06..

[12]  Milan M. Jovanovic,et al.  Light-Load Efficiency Optimization Method , 2009, 2009 Twenty-Fourth Annual IEEE Applied Power Electronics Conference and Exposition.