The Design Of Coordinated Controller For Turbo-generator Excitation And Valve

In the smart grid era, with different levels and forms of voltage interconnection, how to ensure the stability of power systems is increasingly important. In particular, the power system can overcome disturbances after subjected to various forms of disturbance and quickly restore stability. In recent years, many domestic and foreign scholars have conducted extensive research and have achieved fruitful results, but there are still issues to be addressed.This paper first discusses the need for power system stability control. The control of power generator which as a major equipment of power system is difficult and complex since it is a complex nonlinear dynamic systems. Then, the dissertation shows the recent domestic and foreign research of generator’s excitation and valve control system, and finds the key issues for further research in order to constitute systemic theory and methods. Research finds that with valve control can improve power system transient stability, pointing out that the need for coordination control. This paper has carried out the following research works:1. Turbine generator composes excitation control system and steam conditioning system, which modeling is based on mechanism. The derivation of practical mathematical model of turbo-generator’s excitation and valve coordination control basing on a lot of reference.2. The design of linear quadratic optimal coordinated controller based on the mathematical model of generator excitation and valve coordinated control. Simulation results show that excitation and valve coordinated control is of good dynamic and static performance quality, making the system damping increases and oscillation frequency decreased. The controller with good regulation performance after the power system objected to a small disturbance, improving transmission system transient stability limit.3. The design of generator excitation and valve nonlinear coordinated controller is according to modern nonlinear optimal control theory. The idea is to make constraint equations linear or part exact linear by appropriate coordinate transformation and nonlinear feedback.4. The comparison simulation experiments are carried out with the two designed controllers. Simulation results show that, when the system deviates from the design operating point, the dynamic performance and stability of linear coordination controller declines. However, nonlinear optimal coordination controller has the ability to remedy the defect, increasing stable operation range.