Modeling and stability analysis of microgrid with high proportion of renewable energy generation

With the proportion of renewable energy generation in the microgrid increasing, the microgrid AC bus voltage may occur oscillation, and even lead to microgrid collapse in some extreme cases. In order to analyze the stability of microgrid with high proportion of renewable energy generation, this paper takes the microgrid which includes synchronous generator set, grid-connected inverter and constant power load as an example to study. Firstly, the impedance models of synchronous generator set, grid-connected inverter and constant power load are established in this paper. Then, the characteristic polynomial stability criterion is applied to analyze the stability of the microgrid under different proportions of renewable energy generation. Furthermore, the impact of PLL bandwidth and DVC bandwidth for the microgrid stability are analyzed. Finally, a microgrid simulation model is built, and the simulation results verify the accuracy of the microgrid modeling and stability analysis with the microgrid under different proportions of renewable energy generation conditions.