Based On Fuzzy Self-tuning PID Internal Model Control In Steam Generator Water Level

Being the main equipment connection between the first loop and the second loop, it is thekey that ensure steam generator water level is safe and efficient operation. Since the waterlevel system is time-varying and nonlinear, especially, great changes occur in workingcondition of unit,“false water level” phenomenon easily appears in water level of steamgenerator. Therefore, conventional three impulse controller can not achieve good control ofwater level control. The paper based on the internal model control and fuzzy self-tuningcontrol mechanism and research fuzzy self-tuning control internal model control method toachieve the water level in the steam generator.The paper analyzes the characteristics of the steam generator water level control system,the influence of the major factor of water quality control, and establish the mathematicalmodel of the system, the dynamic characteristics of the system under the water and steam flowdisturbances is analyzed. The results show that water flow or steam disturbances, the steamgenerator water level will appear "false water level" phenomenon.Based on the analysis of internal model control mechanism, study the IMC-PID methodof steam generator water level system. Application of internal model control methodestablished by a feedback controller and a feed-forward controller is a combination of waterlevel control system. It consists of a feedback controller and feed-forward controller together.The feed-forward controller is water level control of two order. And the feedback controller isof one order. The idea of using the internal model control to design a controller, through aseries of experiments to test their reaction speed, stability and robustness of anti-disturbance,simulation results show that the IMC-PID effect is better than three impulse control effect.However, when the model parameters change IMC-PID curve appears slight overshoot.Then the paper has a detailed study of fuzzy self-tuning PID control strategy, and has aneffective combination with IMC, the only parameter how to adjust and optimize the feedbackcontroller is discussed. Finally, at50%and100%power, comparing respectively the fuzzyself-tuning control with IMC-PID and three impulse control of water level about unit stepexperiment, applying steam perturbation experiments, model parameter mismatch simulationexperiments. The conclusion is obtained that the model parameters are changed, fuzzy self-tuning PID internal model control effect is still better than the three impulse control effect.