Low frequency oscillation eigenvalue analysis of uncertain system based on perturbation method

A new method is presented to analyze the low frequency oscillation eigenvalues of uncertain system based on second-order perturbation theory. Firstly, the oscillation modes are calculated by first-order and second-order perturbation when system topology changes. Then, with second-order perturbation and interval extension, the interval of eigenvalues and the trajectories of eigenvalues are calculated. Finally, the influence of different parameters to eigenvalues is analyzed quantitatively. Testing results show that the algorithm can track the oscillation modes on-line more accurately compared to first-order perturbation. Furthermore, it can increase the fundamental understanding of inter-area oscillations and is helpful to make correct control strategies to restrain the oscillation.