Average current mode control to improve current distributions in multi-module esonant dc-to-dc converters

Multi-module interleaved resonant converters have been widely adapted to low-profile power supplies for flat-panel display electronics. In this multi-module approach of resonant converter, individual modules tend to have different circuit characteristics due to unavoidable resonant component mismatch, resulting in noticeable imbalance in the module currents and considerable ripple component in the output current. Many researchers have been studied on methodologies for an effective load current sharing for multi-module dc-to-dc converters. But, most of their results were confined to the treatments of passive components. This paper proposes a new average current mode control which actively controls the individual modules to share equal current at the presence of mismatches in their circuit components. The validity and performance of the proposed average current mode control is demonstrated using a 150 W two-module interleaved LLC series resonant dc-to-dc converter designed for LCD TV sets.