A New Framework for Dealing with Input Constraints on Parallel Interconnection of Buck Converters

This paper tackles the current sharing problem for interconnected power converters. Specifically, it considers a single load, fed by parallel buck converters via a common DC bus. In such a case, it has been recently shown that dynamics related to current distribution can be controlled without impacting voltage regulation. Such a decoupling is performed without resorting to frequency separation argument, which inevitably lowers achievable performance. This decoupling can be destroyed by input constraints, though. In this context, this paper shows that a mere unilateral coupling can still be achieved: Using a novel control structure, foremost control goal of voltage regulation can be made independent of current distribution control. Controller design example exploiting the control scheme is provided together with numerical simulations.