Modeling And PID Controller Design In Industrial Polyethylene Process

Melt index and resin density are very important properties, in the production of large-scale polyethylene plant. In the process of production, establishing accurate ethylene polymerization process model, optimizing the grade transition, reducing the quantity of intern and cost of production, are significant to the profit for the enterprise.Ethylene's polymerization mechanism was briefly introduced based on the Unipol process, and then discussed the mechanism of ethylene polymerization. Based on the Hammerstein model, add solution the inverse the non-linear part, identification of the non-linear steady state inverse model is integrated with the SVM theory and PSO,A pseudo linear system was constituted by series connection of inverse model and the nonlinear object, feature modeling algorithm has been used to identify the model. On the controller design, research the LMI algorithm, and the algorithm was extended to discrete systems. Both numerical example and industrial process application are given to illustrate the design procedure and its effectiveness. In addition, a software package with controller performance evaluation, parameters tuning and optimization designed for a typical process control loop. Through the implementation of the project to improve control quality, reduce the production cost and the regulation of operators work.