Evaluation of small signal stability of a two-machine transmission system with robust Power System Stabilizers and Static Var Compensator

Abstract

This work investigated the impact of robust Power System Stabilizers (RPSS) and Static Var Compensator (SVC) on the stability of a two-machine transmission system. To achieve this, a robust power system stabilizer and static var compensator were first developed and thereafter a two-machine transmission system was subsequently modeled in MATLAB/SIMULINK environment and analyzed. Then the response was observed when a single phase-to-ground transient fault was applied to the developed two-machine transmission system at transition time of 5.0s to 5.1s with inclusion of neither RPSS nor SVC. Thereafter RPSS and SVC were separately and simultaneously included in the system and their effects on the system, small signal stability after the fault has been cleared was monitored. This same process was repeated when a three-phase fault was applied to the same two-machine transmission system. The results show that the system evaluates successfully the small signal stability of a bi-machine transmission system only with the application of RPSS when a single-phase fault has occurred and the application of SVC (in addition to RPSS)  when a three-phase fault has occurred.