Coordinated design of unified power flow controller and power system stabilizer to enhance power system stability

In this paper, a modified particle swarm optimization (MPSO) is introduced and applied for simultaneous coordinated designing of the power system stabilizer (PSS) and unified power flow controller (UPFC) as a damping controller in the multi-machine power system. The coordinated design problem of PSS and UPFC controllers over a wide range of loading conditions is formulated as a multi-objective optimization problem. For evaluation of the effectiveness and robustness of the proposed controllers, their performances have been tested on a weakly connected power system subjected to different disturbances, loading conditions, and system parameter variations. The results of these studies show that the proposed coordinated controllers have an excellent capability in damping power system inter-area oscillations and enhance greatly the dynamic stability of the power system.