The Study Of Interactions Between PSS And SVC

Both PSS and SVC can constrain low frequency oscillation effectively, but present research suggests that PSS and SVC will produce some unfavorable interaction effects and destroy stability of power system when they are used to constrain low frequency oscillation at the same time. Since the interaction is very complicated, few research results have been reported. In this thesis, the batch processing function of RTDS was used to coordinate the parameters of PSS and SVC. This method was presented for the first time. It provides a new way to analysis the interactions between traditional and FACTS controllers.Firstly, mathematic model of Low frequency oscillation was established in this thesis. The mathematic models of generator, excitation system, PSS and SVC were also studied in detail. Then the effects of the parameters of these models on low frequency oscillation in a singular generator environment were simulated. Mathematic model of SVC constraining oscillation was established and additive damp controller was designed. Simulating results suggest that only the SVC with additive damp controller can constrain low frequency oscillation effectively. Finally, an integrated program combined C language with Script language in RTDS was compiled to optimize all parameters of models altogether. The availability of the method in a typical four generators system is also verified through simulating results. The results in this thesis provide a new method to solve problems of interaction effects and low frequency oscillation in power system.