Large-Signal Stability Analysis and Control of DC Shipboard Microgrids Considering Battery Dynamic Characteristics

This article presents a large-signal stability analysis and control method for DC shipboard microgrids (DC-SMGs), considering battery dynamic characteristics. The system dynamics are increasingly influenced by the power supply capabilities of energy storage systems (ESSs). However, existing studies seldom address the influence of battery dynamics on the DC bus voltage in SMG systems. To bridge this gap, a full-order dynamic model of the entire system is established, incorporating both the electrodynamics and power characteristics of the battery. Based on a six-month battery testing experiment, a coupled-state model is developed to quantify the battery’s feasible power range. This battery model is then integrated into a generalized current droop control strategy to mitigate DC voltage sags and address variations in battery states. Furthermore, novel stability conditions with peak current constraints are derived using linear matrix inequalities (LMIs). These conditions reveal, for the first time, the influence of battery dynamics on system stability. Simulation results demonstrate that the system’s domain of attraction (DOA) varies significantly with different battery states. Finally, the proposed method is validated through a laboratory-scale experimental prototype system. The voltage fluctuation range is maintained within 23.8 V to 24.2 V, and the fluctuation rate is reduced by 20.41%.