A Simplified Online Stability Monitoring Method for Grid-Connected Systems

With the high penetration of grid-connected inverters in power systems, the instability issues caused by the interaction between inverters and the grid have received increasing attention. To mitigate these issues, monitoring the system stability is a critical step. Conventional stability monitoring methods based on impedance measurement can provide insights into the stability margin of the system and the presence of instability, but often fail to balance the efficiency and accuracy. To solve this problem, this paper proposes an online stability monitoring scheme for grid-connected systems based on impulse-response analysis, which utilizes a specific forbidden region criterion to simplify the complexity of stability analysis. The simulation results validate the theoretical analysis’s effectiveness.