Small-signal stability analysis of islanded DC microgrid under DBS control

There is an increasing focus on DC microgrid nowadays due to its varied advantages. Taking a photovoltaic-based DC microgrid as an example, different operation states are described and the DBS (DC Bus Signaling) control strategy is proposed to keep the power balance. System stability issues arise from dynamical interactions between the components and various loads. In this paper, the small-signal models of interface converters with different control modes are established. Based on the GMPM (the gain margin and phase margin) criterion, the stability of the microgrid in each state and the influence of filter parameters on the stability are discussed. Simulation results verify the correctness of the theoretical analysis and the control strategy.