Design of robust power system stabilizer based on artificial bee colony algorithm

In this thesis, the techniques for a generalized parameter tuning of power system stabilizer to damp the oscillatory modes of generator connected to a single machine infinite bus system is presented. A linear dynamic model is obtained by linearizing the nonlinear model for a power system around an operating point. On the basis of linearized Heffron-Phillips model, a PSS is installed to the power system. The damping function of the PSS with various alternative PSS control signals are investigated. The global optimization techniques such as differential evolution, particle swarm optimization have been applied for the optimization of PSS parameters. A new approach for the optimal design of PSS parameter is investigated and the problem of a robust PSS design is formulated as a multi objective optimization problem and Artificial Bee Colony Algorithm is used to solve it. The effectiveness of the proposed Artificial Bee Colony Algorithm based Power system stabilizers is tested on a single machine power system under different operating conditions and also results are demonstrated through several disturbances. The tuning scheme proposed in this study uses the Differential Evolution, Particle Swarm Optimization and Artificial Bee Colony technique that minimizes settling time and overshoot as well as the control signal violation. Minimizing the overshoot is equivalent to increasing system damping. Moreover a necessary compromise between swiftness of response and allowable overshoot is achieved. The robustness and avoiding conservatism in design, the maximum overshoot is selected to be the worst over wide range operation. It is found that designed robust controller, Artificial Bee Colony Algorithm based Power System Stabilizer provides better damping enhancement for various operating points of single machine system connected to an infinite bus. In addition, the applied method compared with the conventional PSS, the Differential Evolution based Power System Stabilizer and the Particle Swarm Optimization based Power System Stabilizer to analyze the effectiveness of the model. Where as, the proposed controller gains are static and one controller structure is able to damp out the oscillations for different operation points. The proposed method results showed better response behaviour to damp out the oscillations.