A Secondary Partial Energy Phase Shift Regulation LLC Resonant Converter with Current Sharing Ability

This paper proposes a current sharing method for interleaved LLC resonant converter with secondary partial energy phase shift regulation. An AC voltage source with phase shift regulation is constructed and in series with main transformer at secondary side to balance the output currents. With secondary regulation ability, the current imbalance caused by the resonant tank tolerance can be compensated. The major part of power is delivered to load by main transformer, and small portion power is converted by the auxiliary parts, therefore, the energy loss of the conversion is almost as high as conventional LLC resonant converter. The steady state operating principle of the proposed converter is analyzed, and a prototype with two phases current sharing ability is built-up based on the theoretical analysis.