Robust design of multimachine power system stabilizers using simulated annealing

Robust design of multimachine Power System Stabilizers (PSS's) using Simula ted Annealing (SA) optimization technique is presented in this paper. The p roposed approach employs SA to search for optimal parameter settings of a w idely used conventional fixed-structure lead-lag PSS (CPSS). The parameters of the proposed simulated annealing based power system stabilizer (SAPSS) are optimized in order to shift the system electromechanical modes at diffe rent loading conditions and system configurations simultaneously to the lef t in the s-plane. Incorporation of SA as a derivative-free optimization tec hnique in PSS design significantly reduces the computational burden. One of the main advantages of the proposed approach is its robustness to the init ial parameter settings. In addition, the quality of the optimal solution do es not rely on the initial guess. The performance of the proposed SAPSS und er different disturbances and loading conditions is investigated for two mu ltimachine power systems. The eigenvalue analysis and the nonlinear simulat ion results show the effectiveness of the proposed SAPSS's to damp out the local as well as the interarea modes and enhance greatly the system stabili ty over a wide range of loading conditions and system configurations.