Design of state-feedback decentralized nonlinear H∞ controllers in power systems

The paper presents a method of designing state-feedback decentralized nonlinear H-infinity generator excitation control of a power system. The proposed controller. is utilized to damp inter-area oscillations and enhance overall power system damping. The design procedure is presented in terms of positive definite solutions to modified algebraic Riccati inequalities. The resulting controller guarantees closed-loop stability and an H-infinity-norm bound on disturbance attenuation. The control is local or decentralized in the sense that the control of each generator depends only on the information available at that generator. The effectiveness of the decentralized H-infinity controller is demonstrated through digital simulation studies on a nine-bus power system. The digital simulation studies are conducted using a PSCAD/EMTDC software package. (C) 2002 Elsevier Science Ltd. All rights reserved.