A practical load sharing control strategy for DC microgrids and DC supplied houses

Abstract

Microgrid (MG) research mainly focuses on AC-based power flow control techniques. Nevertheless, the rise of DC output sources such as photovoltaic (PV) systems, fuel cells, and distributed batteries leads to the immediate need for DC MGs. In this paper, a hierarchical control strategy for a droop-controlled DC MG is proposed, which fits the smart house infrastructure to adopt online renewable generation and load sharing. The improved control strategies combined with the hierarchical approach includes three loops of controllers: the primary control, the secondary control, and the tertiary control. The issues of internal current limiter and anti-windup are also discussed in this study. The simulation results of the proposed approach are presented to verify the feasibility, and the experimental results are carried out to evaluate the droop concept and secondary voltage compensation.