Application of state feedback based on increment function observer in generator units of power plant in China

Controlled object of generator unit is a nonlinear system. Based on the mechanism mathematical model of the unit plant, a type of incremental mode observer IFO-KΔ_x was described by state space in this paper. Subsequently, it has been proposed a new control method that state feedback based on IFO-KΔ_x combined with conventional PID control. It can overcome the great inertia and the time lag of the boiler controlled object and improve response ability of unit load. At the same time the index of the stabilization was assured by using PID control. The practice has showed that the IFO-KΔ_x has no strict requirement to mathematical model of controlled object. The observer designed has strong steady robustness especially being used in object with characteristics of great inertia and time lag. The control scheme has been applied in some 300 MW and 600 MW generator units of power plants in China. The excellent control result was acquired in boiler-turbine coordinated control system and main steam temperature control system. This control algorithm is brief, practical and easy to be spread.