The paper introduces the impact of coordinated control of combined PSS with either SVC or
STATCOM on the power system stability. They are developed to improve the damping of lowfrequency oscillations in the power system, which are caused by the interactions between the
generator and the transmission line. In addition those FACTS devices are essential solutions for
voltage instability prevention especially under three phase faults condition, through enhancing
the system’s reactive power. Two-machine power system network is used as the test system with
different proposed control schemes and its performance is evaluated through simulations under
different operating conditions. The effects of conventional generic and multiband PSSs, when
each one is applied individually to the testing system in order to make efficient damping process
of low oscillations, are investigated. Multiband PSS showed better performance than the generic
PSS. The results demonstrate the validation of the coordinated control scheme in improving the
power system stability by suppressing low-frequency oscillations and enhancing the overall
damping characteristics. The proposed schemes are superior compared to the individual control
of PSS, SVC, and STATCOM. It is concluded that the combination of PSS with STATCOM
provides more reactive power for more voltage stability under the same operating conditions.