Nonlinear model predictive control of the steam superheating - unmeasured disturbance suppression

This paper deals with the nonlinear model predictive control of the superheated steam temperature in the power plant once-through boiler. Particularly the controller response on impulse of unmeasured disturbance in the form of flue gas heat is investigated. The two different nonlinear predictive controllers are described in the paper. The feedback of the first controller is closed by nonlinear open loop observer with correction for offset free reference tracking. The second controller works with the close loop state and unmeasured disturbance observer based on the nonlinear moving horizon algorithm. Responses of these two controllers and response of the original controller based on the adaptive PID are compared.