Effects of HVDC Link on Small Signal Stability and Inter Area Oscillation for Multi Machines System and Tuning of PSS Using GA

Small signal stability is the investigation of small disturbances impacts in the operating point of power systems on system stability. Therefor the effect of low frequency (inter and local area oscillation) on system stability is very important topic of research especially when large power is transferred between two areas through a weak tie line. This will be accomplished by evaluating the eigenvalues, eigenvectors and participation factor of the linearized different equation of the system. This work will be achieved using Kundur's network system which consists of two area connected by a tie line of 220km length. Several configurations will be studied such as basic (Static) and dynamic control of HVDC link are an important part of this study that taken into a consideration to evaluate the small signal stability, where HVDC link was connected in parallel with one circuit ac tie line. In addition, an Intelligent method which is Genetic Algorithm (GA) is used for tuning the PSS in order to find the optimum values of the gain (K) that give the best system stability.