Improvement on probabilistic small-signal stability of power system with large-scale wind farm integration

This paper studies probabilistic small-signal stability of power systems with wind farm integration, considering the stochastic uncertainty of system operating conditions. The distribution function of the real-part of system eigenvalue is computed by the method of probabilistic eigenvalue analysis. For improving probabilistic small-signal stability, PSS is adopted. A method for optimizing PSS based on participation factor and center frequency method is proposed. In order to evaluate the above proposed methods, the procedure is applied to a test system. The simulation results show that the stochastic variation of wind generation can induce a higher probability of system instability when compared with one that has no wind generation. With eigenvalues distributing in a wider range, it becomes difficult for PSS tuning. By applying the proposed optimized PSSs approach, probabilistic stability of system can be significantly improved.