Efficient system parameter selection to prevent oscillatory voltage instability

In this paper the effects of suitable adjustment of power system controllers including AVR, PSS, and FACT devices on the stability of power system are illustrated. The analysis is base on bifurcation theory, small signal stability evaluation and time domain simulations. A new and efficient procedure is proposed to increase voltage stability margin and to overcome oscillatory instability by adopting appropriate parameter values within plausible range for the system controllers. Effect of SVC and TCSC devices on system performance are considered and compared in detail. At first, the stability of the test system without FACT devices is investigated. Then, static and dynamic analyses are repeated for the system including SVC and TCSC devices, with optimal placement algorithms . multi-parameter bifurcation analysis is presented to study the effect of system parameters on the Hopf and saddle node bifurcations, and to achieve the best controller parameters values to prevent oscillatory voltage instability in the system .