A Novel Current Sharing Method by Grouping Transformer's Secondary Windings for a Multiphase LLC Resonant Converter

A novel current sharing method for a multiphase LLC resonant converter is proposed in this article. Without additional components or control strategies, the proposed method can achieve good current sharing performance even with 10% tolerance of the resonant parameters. Besides, the proposed method is very simple; only the secondary windings of the transformers need to be grouped. This method does not affect the efficiency and load transient characteristics of the LLC resonant converter. The excellent current sharing capability of the proposed method is demonstrated via theoretical analysis under first harmonic approximation assumption and powersim simulation. The experimental results of a 960-W two-phase LLC resonant converter prototype are provided to verify the effectiveness of the proposed method.

[1]  Gun-Woo Moon,et al.  Load sharing characteristic of two-phase interleaved LLC resonant converter with parallel and series input structure , 2009, 2009 IEEE Energy Conversion Congress and Exposition.

[2]  Dehong Xu,et al.  LLC resonant converter for 48 V to 0.9 V VRM , 2004, 2004 IEEE 35th Annual Power Electronics Specialists Conference (IEEE Cat. No.04CH37551).

[3]  F. Lee,et al.  LLC resonant converter for front end DC/DC conversion , 2002, APEC. Seventeenth Annual IEEE Applied Power Electronics Conference and Exposition (Cat. No.02CH37335).

[4]  J. Uceda,et al.  Modeling High-Frequency Multiwinding Magnetic Components Using Finite-Element Analysis , 2007, IEEE Transactions on Magnetics.

[5]  P. Mattavelli,et al.  Two-phase interleaved LLC resonant converter with current-controlled inductor , 2009, 2009 Brazilian Power Electronics Conference.

[6]  Yang Chen,et al.  A Passive-Impedance-Matching Technology to Achieve Automatic Current Sharing for a Multiphase Resonant Converter , 2017, IEEE Transactions on Power Electronics.

[7]  Yeong-Her Wang,et al.  Analysis of a novel resonant converter with series connected transformers , 2013 .

[9]  Adrian Ioinovici,et al.  LLC resonant converter operated at constant switching frequency and controlled by means of a switched-capacitor circuit , 2013, 2013 1st International Future Energy Electronics Conference (IFEEC).

[10]  Jose A. Cobos,et al.  A simplified capacitive model for center-tapped multi-windings transformers , 2015, 2015 IEEE Applied Power Electronics Conference and Exposition (APEC).

[11]  P. L. Chen,et al.  Analysis of LLC converter with series-parallel connection , 2010, 2010 5th IEEE Conference on Industrial Electronics and Applications.

[12]  N. Froehleke,et al.  Paralleling of LLC resonant converters using frequency controlled current balancing , 2008, 2008 IEEE Power Electronics Specialists Conference.

[13]  T. Jin,et al.  Multiphase LLC Series Resonant Converter for Microprocessor Voltage Regulation , 2006, Conference Record of the 2006 IEEE Industry Applications Conference Forty-First IAS Annual Meeting.

[14]  Fujio Kurokawa,et al.  An Interleaved PFM LLC Resonant Converter With Phase-Shift Compensation , 2016, IEEE Transactions on Power Electronics.

[15]  Yan-Fei Liu,et al.  An interleaving and load sharing method for multiphase LLC converters , 2013, 2013 Twenty-Eighth Annual IEEE Applied Power Electronics Conference and Exposition (APEC).

[16]  Yousheng Wang,et al.  A novel ZVS and ZCS three-port LLC resonant converter for renewable energy systems , 2014, 2014 IEEE Energy Conversion Congress and Exposition (ECCE).

[17]  Yang Chen,et al.  A common capacitor multi-phase LLC resonant converter , 2016, 2016 IEEE Applied Power Electronics Conference and Exposition (APEC).

[18]  Wuhua Li,et al.  Asymmetrical Duty Cycle-Controlled LLC Resonant Converter With Equivalent Switching Frequency Doubler , 2016, IEEE Transactions on Power Electronics.

[19]  Paolo Mattavelli,et al.  Current sharing in three-phase LLC interleaved resonant converter , 2009, 2009 IEEE Energy Conversion Congress and Exposition.

[20]  Shu Yuen Ron Hui,et al.  Experimental determination of stray capacitances in high frequency transformers , 2003 .

[21]  Yang Chen,et al.  A Passive Current Sharing Method With Common Inductor Multiphase LLC Resonant Converter , 2017, IEEE Transactions on Power Electronics.

[22]  Yan-Fei Liu,et al.  A Control Strategy and Design Method for Interleaved LLC Converters Operating at Variable Switching Frequency , 2014, IEEE Transactions on Power Electronics.

[23]  Yan Zhang,et al.  Common Capacitor Multiphase LLC Converter With Passive Current Sharing Ability , 2018, IEEE Transactions on Power Electronics.

[24]  Lei Qi,et al.  A Terminal Capacitance Method for Analyzing Global Capacitive Effects of Magnetic Components , 2017, IEEE Transactions on Electromagnetic Compatibility.

[25]  Jianhua Du,et al.  A novel current sharing method for multi-module LLC resonant converters , 2017, IECON 2017 - 43rd Annual Conference of the IEEE Industrial Electronics Society.

[26]  K. Murata,et al.  Performance characteristic of interleaved LLC resonant converter with phase shift modulation , 2015, 2015 IEEE International Telecommunications Energy Conference (INTELEC).

[27]  Bor-Ren Lin,et al.  ZVS Resonant Converter With Parallel–Series Transformer Connection , 2011, IEEE Transactions on Industrial Electronics.