Robust Design of Power System Stabilizer using Harmony Search Algorithm

In this paper, a novel Harmony Search algorithm (HSA) based approach for robust and optimal design of PID controller connected to power system stabilizer (PSS) is proposed for damping low frequency power oscillations of a single machine infinite bus bar (SMIB) power system. This paper attempts to optimize the three parameters (Kp, Ki, Kd) of PID-PSS via a music-based metaheuristic optimization algorithm inspired by the observation that the aim of music is to search for a perfect state of harmony. The problem of robustly selecting the parameters of the PSS is converted to an optimization problem which is solved by a Harmony Search Algorithm with a carefully selected objective function. The eigenvalue analysis and the simulation results obtained for internal and external disturbances for a wide range of operating conditions show the effectiveness and robustness of the proposed Harmony Search Algorithm based PSS (HSAPSS). Further, the time domain simulation results when compared with those obtained using conventional PSS (CPSS) and Genetic Algorithm based PSS (GAPSS) show the superiority of the proposed design.