A method for analyzing the stability of inverter-dominated microgrids

With the continuous advancement of the "carbon peak" and "carbon neutrality" strategy, the distributed power sources are steadily increasing, leading to the emergence of microgrids dominated by distributed power sources. This paper proposes a for analyzing the stability of inverter-dominated microgrids. Firstly, the microgrids’ small signal analysis model is established, including critical components such as synchronous generator sets, inverters. By incorporating these elements, the model can accurately represent the dynamic behavior of the microgrid under various operating conditions. The Nyquist stability criterion is then employed to systematically analyze the impact factors of the microgrids’ stability, including control bandwidth of current-loop, PLL, dc-voltage-loop. The analysis indicates that an increase in distributed power generation reduces the system's stability margin, and adjust the control parameter can improve the stability characteristics. Finally, simulation analysis is conducted to verify the conclusions derived from the analysis.