Design On Automatic Mould Level Control System Of Caster

With constant improvement of automation technology,continuous casting technology is getting consistent development also,the requirements for high quality steel have become more and more strict,therefore,to improve the mould quality is the trend of steel making and keep the mould level within an expected range is an important part of upgrading mould quality.This article is focus on slab caster with one strand of steel plant,aiming at the poor anti-interference ability of tranditonal PID controller used in mould level control system,this paper adopts non-linear PID control scheme to provide an analysis and research on design of mould level controller.In summary,this paper has completed the following works:(1)The model of mould level control system is presented and system hardware is configurated.Mould level control system was analyzed and model was created,and then made an overall plan for mould level control system on that basis,constructed the structure of system,analyzed and researched the performance characteristic of each component.(2)The program flowchart of main functions and non-linear PID controller design for mould level control system.The major functions of casting procedure were analyzed,and created program flowchart based on the former process,such as autostart,stopper calibration and etc,the research and design for non-linear PID controller were the key problems to be solved.In precondition of satisfying normal casting requirement,it raised the innovation of this paper.(3)The development of Human Machine Interface,field debugging and analysis of mould level control system.By modifying the paramters of HMI to adjust PID value,eliminate the influence of mould level detection because of mould width change,improve erosion of slagline sleeve,and locate the fault point quickly and accurately by pages of System Information and Alarms.Field debugging and data analysis have been completed for major casting functions.The field debugging results showed that mould level control system based on Siemens S7-400 controller,VUHZ mould level detector and evaluation unit,SERT servo-drive and actuator which controlled by analog signals can make the movements of stopper mechanism quickly and precisely,therefore,it can fully meet the requirements of normal casting,and keep the mould level within ±3mm near set point over 95%of casting time in auto mode,thus minimizes the mould level fluctuation and improves the mould quality maximally.