Optimal coordinated PET and generator excitation control for power systems

Power electronic transformer (PET) is a new type of transformer, which realizes voltage transformation and power delivery in a power system through power electronic conversion. This paper aims to apply PET to power system and propose a new coordinated control strategy to improve the system stability by a generator-PET unit. We first develop a power system model with a generator-PET unit, and then propose a new optimal coordinated PET and synchronous generator excitation control strategy. Simulation results demonstrate that the proposed controller is superior to the conventional approaches in terms of dynamical performances for a variety of disturbances. Compared with the conventional generator-transformer unit equipped with AVR+PSS controller, the optimal coordinated controller can improve the system damping and voltage characteristics effectively. (c) 2005 Elsevier Ltd. All rights reserved.