Critical Eigenvalues Tracing for Power System Analysis via Continuation of Invariant Subspaces and Projected Arnoldi Method

The continuation of the invariant subspaces algorithm combined with the projected Arnoldi method is presented to trace the critical (right-most or least damping ratio) eigenvalues for the power system stability analysis. A predictor-corrector method is applied to calculate the critical eigenvalues trajectories as power system parameters change. The method can handle eigenvalues with any multiplicity and very close eigenvalues during the tracing processes. The subspace dimension inflation and deflation is applied to deal with eigenvalue overlap. The subspace update is proposed by an efficient projected Arnoldi method that can utilize known information from the traced eigenvalues and subspaces