Research And Application Of Fuzzy-PID Series Level Control System At The Sewage Treatment Plant

With the deterioration of the water environment, the sewage treatmenttechnology in china has made a considerable development. However, in the sewagetreatment process, the original techniques generally focus on the process operatingparameters, however, ignore the influence of external parameters such as liquid level.Considering the level parameters are complex, nonlinear, and it is important toaccurately control the liquid, which will contribute to protect the motor and reduceenergy consumption.In these research, method AAO has been applied to control the level of sewage.First, principles and features of AAO were introduced; and then the impact factors formethod AAO were analyzed, especially the level parameter. The single-tank modelwas selected in this study and a mathematical model has been set up. Theconventional PID and fuzzy control was combined to realize the automatically controlthe level by the method AAO, which could improve the efficiency of sewagetreatment, and reduce to impact load, finally ensure the smooth running of the sewagetreatment process.A systematic analysis of level parameters in AAO process was conductedthrough the MATLAB software. After simulation and comparison of PID, Fuzzy, andFuzzy PID series control method, Fuzzy PID series control method was selected andapplied into practical level control in Ningbo North Treatment Plant. Finally, it wasconfirmed that the fuzzy PID series control strategy is valid and rational according tothe analysis of the trends of the level control parameters during the operation process.