Enhancing Stability Limits of Smib Power Systems Using Pidpss Based on Modified Firefly Algorithms

Abstract

Power system stabilizers (PSS) are employed in modern power networks to ensure stable
operations including extreme operating conditions. As operating conditions are changing system
parameters are also getting changed and to ensure stability, the parameters of PSS have to be adjusted
accordingly. Several optimization algorithms are in use for tuning of PSS and swarm intelligence is
widely used now a days. Firefly algorithm is one such method but having a serious drawback of getting
trapped into local optima rather than converging to global optima. To overcome this difficulty modified
firefly algorithms are also suggested. This study compares two such modifications Firefly Photinus
Algorithm (FPA) and Tidal Force Firefly Algorithm (TFFA) used for tuning proportional Integral plus
Derivative Power System Stabilizers (PIDPSS). Single Machine infinite Bus Power System with
changing operating conditions is tested to investigate the effectiveness of the algorithms. Both the
modifications found improving system stability substantially with TFFA getting an edge over the
other.