Rapid Critical Eigenmodes Tracing via Inertia Equivalence in State Space

The damping characteristics of critical electromechanical eigenmodes are varied with the power system conditions like the renewable energy fluctuations. However, the traditional eigenanalysis is difficult to trace the dynamic stability of high-order systems. Considering the variation of system parameters, we propose a rapid tracing method for the critical eigenmodes in this paper. For the tracing acceleration, the original state matrix order is reduced by inertia equivalence, and state variables are mapped to low-dimensional subspaces upon the generator clustering. When the cluster varies, a cluster variation index is proposed, and the classical QR method will be switched to guarantee the reliability of the traced critical eigenmodes. The comparison with the QR method verifies the effectiveness of the framework. Simulation tests demonstrate the accuracy and rapidity of the proposed method in critical eigenmode tracing.