Small Signal Stability Analysis of Micro-source Inverter System in Grid-connected Series Micro-grid

In order to accurately analyze the small signal stability of micro-source inverter system in grid-connected series micro-grid, the paper establishes a small signal model of grid-connected series micro-grid system, including the series connection model, power controller model, phase locked loop model, power and current controller model, load and network model. Based on the model, the step response of the state variable of the system is calculated when the active load is increased, and the feasibility of the model is validated by MATLAB/Simulink software. Meanwhile, we can calculate the initial value of the system and the eigenvalues of the coefficient matrix of the equivalent resistance change, we further analyzes the small signal stability of micro-source inverter system in grid-connected series micro-grid. At the same time, the correctness of the theory is verified by simulation.