Linear QFT control of a highly nonlinear multi-machine power system

A quantitative feedback theory (QFT) method of Horowitz, treating nonlinear ities as equivalent disturbances, is applied to the linear control of a mul ti-machine power system. This system has a smooth nonlinear dynamics so the original approach was simplified. From the design point of view good resul ts were obtained with simple controllers (automatic voltage regulator, spee d governor, power system stabilizer) when the power system was affected by large load variations and short circuits. To reduce significantly the stead y state errors which appeared, a novel rotor speed error amplification sche me was employed. This increased the autonomy of the controlled power system to combat big distortions from normal operating conditions. Copyright (C) 2001 John Wiley & Sons, Ltd.