Coupled and Decoupled Nonlinear Control of Generator Excitation and SVC

This paper presents a unified nonlinear robust control design for transient stability and voltage regulation by means of generator excitation and static var compensator (SVC) system. The effect of coupled and decoupled dynamics between excitation and SVC is taken into account to achieve performance enhancing power system stability control. Direct feedback linearization (DFL) and robust control theory have been employed to design controls independent of the operating point. Simulation results indicate that control designs based on decoupled system models are stability enhancing over a very wide area whilst controllers considering coupling effects are limited in their stabilizing properties. The study presented in this paper is carried out on a single machine infinite bus (SMIB) power system model undergoing a large sudden fault at the generator terminal bus.