Study Of Optimal Control Of Multipurpose Station Refining And Transmission System

The multipurpose station refining and transmission control system is studied in this paper. The modeling and control scheme are given.After analyzing the theory of multipurpose station refining and transmission system, in this paper, the technics flow and parameters are introduced, the system variables and the relation of variables are analyzed.In this paper, the first time, the wavelet analysis theory is used to deal with the signals of multipurpose station refining and transmission system, based on the wavelet multiresolution character, the jerk signals caused by disturbance are weeded, the useful system output and input trend signals are obtained.The more, with the dispart frequency ability of wavelet, the decompose/synthesis filter is designed to treat with signals. In every frequency, estimating the transfer function of system and combining them, then, the final liner model of multipurpose station refining and transmission system is the first time built. The simulation result show that the model is valid, the model's output change trend is identical with the practical object responds.To the process control, predictive control has gotten quantum succeed in so many field. Aim at resolving the practical problem, i. e. the parameters in the process of oil dehydration are over-coupling, in this paper, the dynamic matrix predictive control algorithm with restriction was discussed to control the system, and a multivariable DMC control algorithm with forward-feedback and restriction was given. Used the algorithm to control electric dehydration system, the simulation result showed that when the disturbance is small, the algorithm was effective, but when the disturbance is large, the control algorithm is not successful.In order to supply a gap of predictive control, the Hx robust control algorithm is selected to control the multipurpose station refining and transmission system. In this paper, the theory, to design the disturbance weight matrix based on input flow spectrum energy analysis, is put forward, and rational weight matrix is selected. Based on the minimum synthesis sensitivity theory, the standard model of system is built. After the condition of resolution being validated, using the ARE means, the multipurpose station refining and transmission system Hx controller is designed.With MATLAB computer simulation and semi-practicality simulation, compared the simulation results, the advantages and disadvantages of these two control schemes are clear. Based on sliding-mode control theory, in this paper, we brought forward a new control theory: multi-mode control, and deal the Hx controller and predictive controller with this theory. In system simulation lab, the simulation result show that the main controlled variables, pressures and heights of oil-water interface of free water dehydrators and electric dehydrators , are stable; the main control targets, the purified oil water containing ratio and sewage containing ratio, are meet. The control scheme resolves the control problems of multipurpose station refining and transmission system, in favor of the safety production, decreasing worker's labor intensity, and improve the benefit. It has important meaning to improve the automatic control level of electric dehydration of combination station.