CONCEPT OF INCREMENT FUNCTION OBSERVER AND ITS APPLICATION IN STATE FEEDBACK CONREOL SYSTEM

Abstract

The state observer theory proffered by Luenberger can resolve the state reconstruct of linear control system in case of the conclusive condition. But the entire actual world has characteristic of nonlinear at some extent. This paper describes a type of nonlinear system by means of model of Hammerstein. Based on which, the concept of increment function observer was presented clearly. Starting from the basic definition, it was certified by mathematical analyses that all of Luenberger function observer, full dimension state observer and increment state observer is special case of increment function observer. With mathematical definition of increment function observer is based on nonlinear controlled system, so application of observer can be able to extend nonlinear control field. The theory analysis shows that the robustness of increment function observer precede that of robust Luenberger observer, premising parameters of the two type of observer are same. It has been certificated by practices of engineering application of 6×300MW unit generators in 3 power plants that state feedback control based on increment function observer combined with PID control can be able to achieve high quality control index to large lag complexity controlled object, which has strong steady robustness and its control algorithm is briefness, practicality and easy to spread.