Design of decentralized controllers for large power systems considering sparsity

This paper proposes a method for the design of power system controllers aimed at damping out electromechanical oscillations. It can be applied to the design of both power system stabilizers (PSSs) for synchronous generators and supplementary signals associated to other damping sources. Some attractive features of the method are: the parameters of all controllers are jointly determined, there is no restrictions on the type of supplementary signals to be used, and controller structures are compatible with those nowadays employed in electric utilities. The control problem solution exploits sparsity, combining a system description which preserves a sparse structure with an adequate mathematical formulation of the optimal design approach. The resulting method is thus made applicable to large power systems. Results for two test systems, including a large 750-bus system, are presented. For both systems, settings for several power system stabilizers are simultaneously determined. The results are validated by using both eigenvalue analysis and nonlinear simulation.