Large signal stability analysis of DC microgrid group based on droop control

In DC microgrid group, constant power load will lead to bus voltage fluctuation due to its own characteristics. This paper takes the bus voltage of DC microgrid group as the research object, analyzes the large signal stability of DC microgrid group with constant power load on the basis of drooping control, analyzes the large signal stability of the system by using mixed potential function method, and derives the large signal stability criterion of DC microgrid group. In MATLAB/Simulink, the DC microgrid group was connected to constant power load at a certain moment to simulate the large disturbance of DC microgrid group. The simulation results show that the DC microgrid group can maintain stable operation if the constant power load of dc microgrid group meets the stability criterion. If the stability criterion is not met, the system crashes. According to the stability criterion, the stability of large signal can be improved by increasing capacitance value or decreasing inductance value, and the feasibility of this method is verified by simulation.