New Masterless Modular Current-Sharing technique for DC/DC Parallel converters

This article presents a new Masterless Modular Current-Sharing (MMCS) technique. Current-sharing modules are identical and placed in a daisy chain configuration. Unlike classical current sharing which consists in comparing each phase current to a global computed average value, the presented masterless approach computes local current average values. Phase currents´ balancing is achieved by comparing each phase current with the average value of its adjacent phase currents. This technique is validated by a mathematical demonstration and compared with the classical current sharing technique. MMCS approach is adapted to DC/DC Parallel converters with coupled inductors. Such topologies require extremely precise current-sensing technique. An accurate differential current-sensing technique with fluxgate sensor is proposed and applied to MMCS technique. Filters design and its architecture for current sharing loop are explained. Finally, experimentation on a six-phase DC/DC converter with coupled inductors is achieved and validates both MMCS and differential current sensing techniques.