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.