Research On Optimal Control Of Edge Drop Of Cold Rolled Silicon Steel

The edge drop index is one of the important criteria for judging the quality of coldrolled silicon steel.Silicon steel is widely used as an important raw material in the industrial production of transformers due to its good magnetic permeability.Since the transformer production process needs to "laminate" silicon steel,the surface quality requirements of the silicon steel thickness will be higher,so the amount of edge drop will directly affect the trimming amount of the finished silicon steel.Downstream users continue to improve the quality requirements of cold-rolled silicon steel.The control technology of lower edge drop has become a hot spot for scholars at home and abroad.This subject relies on a 1500 mm five-stand UCMW cold-rolled silicon steel unit in a steel plant as the research object,combined with actual unit equipment,on-site technology and control technology,to study the generation mechanism and control technology of cold-rolled silicon steel edge drop And analysis,the main content is as follows.Firstly,aiming at the problem of improper characterization of edge drop,a more objective characterization method of edge drop is proposed.In order to analyze the generation mechanism of edge drop,a simulated rolling model was established by finite element method,and the influence of different process parameters including different reduction rates,thickness,work roll diameter,elastic deformation and elastic flattening,and control methods were analyzed.Including the influence of work roll traverse,bending force and tension on edge drop,it provides theoretical and simulation data support for subsequent research.Secondly,in view of the problem that the optimal adjustment amount is difficult to control for the single taper work roll's lateral shift variable adjustment efficiency coefficient,a method for solving the optimal adjustment amount based on the variable control efficiency coefficient is proposed.Obtain a preliminary model of the influence law of the work roll on the edge drop through the simulation model,perform a high-order fitting of the preliminary model,introduce a penalty function to constrain the solution amount,construct an objective function and use an optimization algorithm to achieve the optimal control amount The solution.Through experimental comparison,it is found that the optimal control of variable control efficiency can achieve high-precision and stable control of edge drop.Finally,in view of the time-delay control problem in the edge drop closed-loop control,a time-delay control method of model predictive control and process drive control is proposed.Analyze the cause of the time-delay,calculate the delay time of the control system,establish a predictive preliminary model through simulation data,use process data to correct the accuracy of the predictive model,introduce the predictive time-limit value as the predictive process value,optimize the trajectory of the control process,and a more stable,higher-precision time-delay closed-loop control of edge drop is realized.Through simulation experiments and comparison experiments,the results prove that the predictive control method has higher control accuracy and faster control speed,and can meet highprecision edge drop control.