The Design for Feed Water System of Boiler Based on Fuzzy Immune Smith Control

Aiming at the uncertainty of model parameters and dominate time delay of the controlled object in feed water system of boiler, combined with improved Smith predictor control method and fuzzy immune PID control method, improved Smith predicting controller based on fuzzy immune is designed. Fuzzy Immune PID controller can self-tune parameters, and has adaptive capacity to the diversification of controlled object parameters. When there is the phenomenon of large delay, the predictor estimates in advance the dynamic characteristics of the process under basic disturbance, so that regulator takes action ahead of time to reduce the overshoot. The designed controller is applied to the feed water cascade control system, and is simulated by Matlab under different operating conditions. Simulation results show that the designed control system has strong adaptive ability to the diversification of model parameters. And its stability, accuracy are superior to that of conventional Smith control system. The effectiveness of this designed controller has been confirmed.