Probabilistic small signal stability analysis of power system integrated with large-scale wind farm considering multi operating conditions

The probabilistic method is applied in the research on probabilistic small-signal stability of power grid integrated with large-scale wind farm under multi operation conditions. Firstly, using plug-in modeling technique (PMT) a completer linearized model of doubly fed induction generator (DFIG) suitable to the analysis on small-signal stability is established; secondly, the probabilistic power flow calculation is performed to obtain probabilistic description of system state variables and the system state matrix is formed; finally, using probabilistic eigen-root method the established system is solved and analyzed to obtain probabilistic small-signal stability of the whole system. Taking the modified IEEE 3-machine 9-bus system and a modified 4-machine 2-area system for examples, the simulation and analysis on probabilistic small-signal stability of power grid integrated with wind farm are performed. Simulation results show that power grid integrated with wind power makes: A) the probabilistic distribution of the real part of modal eigenvalue of electromechanical oscillation becomes relatively dispersed; B) probability of modal stability of local oscillation is greatly decreased and probability of modal stability of inter-area oscillation is slightly increased; C) it is enable to enhance the probabilistic small-signal stability of the whole system by adding power system stabilizer (PSS).