Comparison of Power System Stabiliser with Series and Shunt Facts Controllers in Damping Power System Oscillations

Abstract

This paper discusses and compares different control techniques for damping undesirable electromechancial oscillations in power systems by means of power system stabiliser (PSS) and series/shunt FACTS (flexible AC transmission system) controllers. The linearised model of the power system is derived with FACTS controllers and the problem is formulated as an optimisation problem to maximise the damping ratio of the power system. Particle swarm optimisation (PSO) technique is applied to tune the controller parameters of the PSS and FACTS controllers. The following FACTs controllers are taken for analysis: (i) static Var compensator (SVC); (ii) static compensator (STATCOM); (iii) thyristor controlled series capacitor (TCSC); and (iv) unified power flow controller (UPFC). The time domain simulation results are carried out using EUROSTAG 4.3, which provides necessary information about the dynamic reactive power support required by shunt FACTS controllers and the dynamic MVA rating of series FACTS controllers for small signal/transient stability enhancement.