Robust PSS Design under Multioperating Conditions Using Canonical Particle Swarm Optimization

Power system stabilizer (PSS) is one the most economical and effective controllers to enhance the power system damping. Under multioperating conditions, the probabilistic PSS (PPSS) design problem can be formulated as a parameter optimization problem with probabilistic eigenanalysis included and the statistical nature of the eigenvalues is described by their expectations and variances. This paper uses the canonical particle swarm optimization to address PPSS design problem so as to overcome the deficiency of traditional derivative-based methods and other heuristic techniques. The effectiveness and robustness of the proposed PSS design approach has been tested based on a three-machine system. A comparison between the proposed approach and a conventional sensitivity-based PSS design method is conducted by nonlinear time domain simulation and the results show the effectiveness of proposed approach. Two performance indices are calculated and the results are in consistence with the transient process simulation.