Value-Set-Based Power System Robust Stability Analysis: Further Results

This paper presents some further results for multi-parameter robust stability analysis of large-scale power systems. A finite frequency test is first applied to check robust stability of the system. The parametric stability margins are then calculated to measure the degree of robust stability at different frequencies. The uncertainty's effects on stability are revealed by tracing the value set movements at the worst case frequency. The proposed approach allows the value set plot to be generated automatically, and is applicable to a substantially large number of parameters. The advantages of the approach derive from the affine uncertainty of the characteristic polynomial; for large-scale power systems, we explain that such affine uncertainty usually exists. Case studies of the 547-machine 8647-bus China system are reported, revealing that the suggested value set method appears to be a practical tool for real-world stability analysis.