Optimal Placement of SVC using Residue Technique and Coordination with PSS for Damping Inter-Area Oscillations

Local mode and inter-area mode are slowly growing oscillations affects the stability of the power system significantly becasue such growing oscillations for long time may lead to the blackout of the system. The oscillatory mode instability occurs in the power system due to various reasons like fast-acting exciters with high gain, heavy power transfer over a weak transmission line, etc. In this paper, static var compensator (SVC) is used to improve the system stability and performance by providing damping to the low-frequency inter-area mode of oscillation. To provide damping effectively to such mode simultaneous tuning of SVC and power system stabilizer (PSS) is mendatory under the different operating conditions of the power system. Moreover, to achieve controllability in the power system, the flexible ac transmission systems (FACTS) device and the PSS should be located optimally. In this paper, a residue-based method has been used to find the optimal location of the SVC controller for damping of the inter-area mode of oscillations and the optimal location of PSS is determined by participation factors. The proposed method is implemented on Four-machine, Ten-bus, Two-area test system. Simulation studies have been carried out in MATLAB/Simulink platform to verify the performance of with and without SVC and PSS for the test systems under three operating conditions, i.e., light loading, nominal loading, heavy loading conditions. In addition to this, eigenvalue analysis and time-domain simulation results are used to evaluate the performance of the system under above three loading conditions. The results confirm that the proposed approach significantly enhances the stability of the inter-area oscillation mode under all loading conditions.