Nonlinear output stabilization control for multimachine power systems

In this paper, a robust decentralized nonlinear control scheme is proposed for multimachine power system stability enhancement. The nonlinear controll er consists of a novel dynamic direct feedback linearization (DFL) compensa tor through the excitation loop to cancel the nonlinearities and interactio ns among generators and a robust feedback controller to guarantee the asymp totic stability of the DFL compensated system considering the effects of dy namic output feedback and plant parametric uncertainties. The decentralized controller for each generator in the multimachine system is obtained by so lving an algebraic Riccati equation. The nonlinear controller can guarantee the stability of the multimachine nonlinear power system within a whole op erating region for all admissible parameters. The design procedure is teste d on a three-machine power system. Simulation results show that the propose d control scheme can greatly enhance the stability of the system, regardles s of the network parameters, operating points, and fault locations.