Optimization and coordination of damping controls for optimal oscillations damping in multi-machine power system

This paper proposes a novel optimization technique for simultaneous coordinated designing of power system stabilizer (PSS) and static VAR compensator (SVC) as a damping controller in the multi-machine power system. PSO and chaos theory is hybridized to form a chaotic PSO (CPSO), which reasonably combines the population-based evolutionary searching ability of PSO and chaotic searching behavior. The coordinated design problem of PSS and SVC controllers over a wide range of loading conditions are formulated as a multi-objective optimization problem which is the aggregation of the two objectives related to the damping ratio and damping factor. The proposed damping controllers are tested on a weakly connected power system. The effectiveness of the proposed controllers is demonstrated through the eigenvalue analysis and nonlinear time-domain simulation. The results of these studies show that the proposed coordinated controllers have an excellent capability in damping power system interarea oscillations and enhance greatly the dynamic stability of the power system. Moreover, it is superior to both the manually coordinated stabilizers of the PSS and the SVC damping controller.