low frequency oscillations suppression via cpso based damping controller

in this paper, the unified power flow controller (upfc) is enhanced with a chaotic particle swarm optimization (cpso) damping controller in order to mitigate the low frequency oscillations (lfo) in a single machine infinite bus (smib) power system. the designed damping controller is an optimized lead-lag controller, which extracts the speed deviation of the generator rotor and generates the output feedback signal, which aims to modulate the reference values of the upfc normal controller to achieve the best damping of lfo. in order to examine the better damping option, the damping controller is applied to both series and shunt converter of the upfc and the results are comprehensively compared in three different operating points. simulation results are performed in matlab/simulink in three different cases and a performance index (pi) analysis is carried out.