Robust Coordinated Design of UPFC Damping Controller and PSS Using Chaotic Optimization Algorithm

A Chaotic Optimization Algorithm (COA) based approach for the robust coordinated design of the UPFC power oscillation damping controller and the conventional power system stabilizer has been investigated in this paper. Chaotic Optimization Algorithms, which have the features of easy implementation, short execution time and robust mechanisms of escaping from local optimum, is a promising tool for engineering applications. The coordinated design problem of PSS and UPFC damping controllers over a wide range of loading conditions and systemconfigurations is formulated as an optimization problem with the time domain -based objective function which is solved by a COA based on Lozi map. Since chaotic mapping enjoys certainty, ergodicity and the stochastic property, the proposed chaotic optimization introduces chaos mapping using Lozi map chaotic sequences which increases its convergence rate and resulting precision. To ensure the robustness of the proposed coordinated controllers tuning, the design process takes into account a wide range of operating conditions and system configurations. The effectiveness of the proposed method is demonstrated through nonlinear time-domain simulation and some performance indices studies under over a wide range of loading conditions. The results of these studies show that the COA based coordinated controller has an excellent capability in damping power system oscillations and enhance greatly the dynamic stability of the power system.