Damping of power system oscillations in multi-machine power systems using coordinate design of PSS and TCSC

In this paper improving of low frequency oscillations of multi-machine power systems using coordinate tuning of PSS and TCSC has been considered. For this purpose linearized model of multi-machine power system which includes the effect of PSS and TCSC has been adopted and after forming the state matrix, eigenvalues of system have been calculated. The desired modes in small signal stability are electromechanical modes, so in this paper the recognition of electromechanical modes have been done using sensitivity analysis of eigenvalues of system with respect to machine inertia. For finding the optimal setting of PSS and TCSC parameters, with use of genetic algorithm an objective function based on damping ratio has been considered in this paper. In order to find the optimal placement of PSS, the Participation Factor (PF) technique will be used, in this technique the proper generator for installing the PSS in its excitation system will be that has most contribution to minimum damping ratio of electromechanical modes. Performance of designed stabilizers has been demonstrated using both eigenvalue analysis and time domain simulation on 9-bus, 3-generator WSCC system with promising the results.