Performance analysis and tuning of FACTS controllers in tandem with PSS in a power system network

Power System Stability and Control has been and continues to be a major concern in the planning, design and operation of modern power systems. The selective use of FACTS controllers, as per the need, alleviates majority of the stability problems and also helps to enhance the grid reliability. FACTS controllers and PSS are generally connected together in modern power systems as they help in damping out the system oscillations, thereby improving the stability of the system. However, if there is no proper coordination between the FACTS controllers and PSS, there may be deleterious interactions between the two. This paper gives a new approach for proper control coordination between the FACTS controllers and PSS, so that the overall stability of the system is improved. For the design purpose, the model of power system considered was the single machine infinite bus (SMIB) system. A comparative study of the performance analysis of STATCOM with PSS and SVC with PSS in the same SMIB system was analyzed. Initially the controllers were independently tuned and then the individually tuned controllers were connected in the system and simultaneously coordinated for improving the stability. The simulations and analysis were carried out using the PSCAD/EMTDC software package. The simulation results show how the effective coordination between the FACTS controller and PSS improved the stability of the system. Also STATCOM gives better performance than SVC when coordinated with PSS.