Stability of DC Distribution Systems: Analytical and Experimental Results

Constant power loads combined with low inertia form a major challenge for future distribution grids. This paper presents a state-space representation to model dc distribution systems. Two methods are discussed to analyze the (small-signal) stability of these dc distribution systems; an algebraic method and a Brayton-Moser method. The system models and the methods for stability analysis were verified using an experimental dc microgrid set-up. Furthermore, it was found that the instability of dc distribution systems can be classified into two categories: equilibrium instability and oscillatory instability.