Decentralized H-infinity control for damping power system oscillations

Inter-area oscillations are serious problems to large-scale power systems. A decentralized H-infinity generator excitation controller of a power system is proposed to damp the inter-area oscillations and to enhance power system stability. The design procedure for a linear composite system is presented in terms of positive semi-definite solutions to modified algebraic inequalities. The resulting controller guarantees closed-loop stability, robustness and an H-infinity-norm bound on disturbance attenuation even under uncertainties such as high frequency noise. The control is decentralized in the sense that the control of each generator depends on local information only. The effectiveness of the H-infinity controller is demonstrated through digital simulation studies on a two-machine power system.