Large-Signal Stability Analysis of DC Microgrid System Considering the Power Characterization of Energy Storage System

The negative impedance characterizaiton of constant power loads (CPLs) easily causes instability of direct current (DC) microgrid systems. Energy storage systems play an important role in the stability of DC microgrid systems. A large-signal stability analysis process that considers power characterization of energy storage system is presented in this paper. Firstly, an equal model of DC microgrid system is derived. The power characterization of energy storage system is analysed based on previous work. Then, the Lyapunov-based stability analysis and existence of equilibrium points are discussed. Two muti-constraints stability criterias are proposed. Finally, the simulation results demonstrate the effectiveness of proposed method.