An Alternative Distributed Control Architecture for Improvement in the Transient Response of DC Microgrids

Distributed secondary control plays an important role in dc microgrids, since it ensures system control objectives, which are power sharing and dc-bus voltage stability. Previous studies have suggested using a control architecture that utilizes a parallel secondary bus voltage and current sharing compensation. However, the parallel controllers have a mutual impact on each other, which degrades the transient performance of the system. This paper reports on an alternative distributed secondary control architecture and controller design process, based on small-signal analysis to alleviate the mutual effect of the current sharing and bus voltage compensation, and to improve the transient response of the system. Experimental results confirm the improved transient performance in the current sharing control and dc-bus voltage stability utilizing the proposed control architecture.