Design of robust power system stabilizers in a multimachine power system using tabu search algorithm

This paper proposed a design of robust power system stabilizers (PSSs) in a multimachine power system using tabu search (TS) algorithm. Each PSS structure used is identical to that of a widely-used conventional lead-lag PSS (CPSS). The proposed design method arranges PSSs and a multimachine power system as a decentralized controller and a multi-input multi-output (MIMO) system, respectively. Practically, suitable parameters of PSSs are difficult to find. To overcome this problem, TS is employed to search for the optimal parameters of PSSs in order to improve the robustness of power system stability. The objective function used includes the robust stability index to acquire the better stability margin while compromising the robust performance. The re-initialization and acceptance criterion are introduced in the proposed TS for improving a diversity of a search process. The performance of designed PSSs under different disturbances and loading conditions is examined in a case of two-area four-machine power system. As results, nonlinear simulation results satisfactorily show the effectiveness and robustness of designed PSSs.