Current distribution control design for paralleled DC/DC converters using slidingmode control

Abstract—This paper shows the analysis and design of a parallel-connected converter system using sliding mode control techniques. The design is particularised for a system that consists of boost converters and a current feedback loop based on a proportional–integral compensator of the output voltage error. The paper emphasises the advantages of the sliding-mode control over the classic design method based on small-signal models, thus providing an effective and robust means of controlling nonlinear multi-input converters. The design is based on the Utkin conditions, which permit us to know the regions under which a sliding mode exists. This fact allows us to design the compensator and to introduce some modifications in the control loop that avoids input-current overshoots during the system startup. Simple design expressions are obtained and verified with simulation and experimental results, thus showing the improvements achieved with the proposed modifications. Index Terms—DC–DC power conversion, power control, vari-able-structure systems. I