A novel active-current-sharing method for interleaved resonant converters

This paper presents a novel active load-current-sharing control of paralleled or interleaved isolated series-resonant converters. In the proposed control method, the output voltage is regulated by variable-frequency control of the converters' primary switches, while a delay-time control is used to control secondary-side switches provided in place of diode rectifiers to correct load-current imbalance between the converters that is caused by their mismatched components. By independently controlling the turn-off delay time of the secondary switches of each individual converter with respect to the zero-crossing instants of the corresponding resonant-tank current, excellent current balancing can be achieved. The evaluation of the proposed control method was performed on a 1.8-kW prototype that was implemented by two interleaved 900-W series-resonant LLC converters operating from a 240-450-V input-voltage range and providing a 13.8-V output.

[1]  V. A. Sankaran,et al.  Electrolytic capacitor life testing and prediction , 1997, IAS '97. Conference Record of the 1997 IEEE Industry Applications Conference Thirty-Second IAS Annual Meeting.

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

[3]  V. A. Sankaran.  Electrolytic Capacitor Life Testing and Pr , 1997 .

[4]  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.

[5]  Milan M. Jovanovic,et al.  Series-resonant converter with reduced-frequency-range control , 2015, 2015 IEEE Applied Power Electronics Conference and Exposition (APEC).

[6]  Michael L. Gasperi,et al.  Life prediction model for aluminum electrolytic capacitors , 1996, IAS '96. Conference Record of the 1996 IEEE Industry Applications Conference Thirty-First IAS Annual Meeting.

[7]  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).

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

[9]  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.