Comparison of Stability Improvement in Multimachine Power System by FACTS Devices

The machine dynamics response to any impact in the system is oscillatory. In past, the size of power system is smaller, therefor the period of oscillation was not much greater than one second. Today large capacity of generator and system interconnected with the greater system inertias and relatively weaker ties results in longer period of oscillation followed by perturbation. These are the situations in which dynamic stability is concern. The enhancement of dynamic stability becomes very important for reliability and continuity of power system. Now power electronic based FACTS (Flexible AC Transmission system) devices are established to enhance the power transmitting capacity and also mitigation of oscillatory period of system at the time of fault. The case study of two area system is taken for analysis. Fault is created for observation of different parameter of machine and transmission system like rotor angle waveform, settling time, voltage of machine, active power of machine and transmission voltage. The different fault analysis says that FACTS controllers help to improve dynamic stability.