Design And Realization Of Cold Rolling Mill Strip Thickness Auto Control System

At present,the market's demands of cold rolling products is improving better gradually,and each large steel plant is expanding production capacity to meet the market demand.Under this market,the costumes also have higher and higher requirements on products quality.The thickness control accuracy is the core quality index of the cold rolled strip.Therefore,the strip thickness and shape control of tandem cold mill is always the focus research.This paper is based on the construction project of the cold rolling plant of XiChang steel&vanadium Co,.Ltd,and makes an in-depth study on design and implementation of the thickness control system of the tandem cold mill.After about one year commission and summary,achieved better results.The core factor of cold rolling mill control system is the thickness control system(AGC).The thickness control system is a complicated control system,including tension control,speed control,the push up control,shape control,hydraulic control,drive control,level 2 math model and so on.If the control system is not correcting promptly when a variable is changing,other stand's steady state will be affected,and also the production and quality of the product will be seriously affected.This paper first introduces the development survey of the thickness control system both at home and abroad,Detailed introduce the significance of the thesis,the main research contents and the problem to be solved.Chapter two is based on the knowledge of rolling mill,analyzed the influencing factors in the thickness control.Chapter three builds the hardware framework of thickness control system and the network configuration.Chapter four and five build the system model from the algorithm and software,design and realization of program and HMI picture.At last,combines site record curves and data,then test and summarize the system.In this paper,the control system used the R700 PLC,the speed adjust system used AC-DC-AC inverter system,to research and realize the cold rolling mill strip thickness auto control system.And combines the requirements of the product technical index,analyzes and optimizes the problems such as thickness variation and shape precision,which also helps a lot in the normal production.