Design Of Control System And Research On Melting Rate Control Method For Vacuum Electro-slag Furnace

In recent years,with the rapid development of world-wild science and technology of metallurgical equipment.All works of life has a increasingly high demand for the quality and quantity of high qualify steel,and vacuum metallurgy is becoming an inevitable trend.High-alloy and high-quality alloy steel,high-end materials applied for aerospace and marine indusrtry and the nuclear industry must be producted in Arc furnace with vacuum,and normal remelting often causes white blots and ring segregation.ESR process can overcome this defect,therefore new airtight vacuum electroslag furnace emerge.The vacuum electroslag remelting technology can improve the quality of steel and alloys and increase their variety.It can bring substantial economic benefits and without any doubt it process a considerable research value and broad application prospects.Based on a research institute of Aeronautical Materials actual project,the characteristics of the process and equipment in vacuum furnace slag are introduced.According to technology and equipment requirements,complete computer control system software and hardware design.The Lower machine uses Siemens PLC S7-300 series production with the core unit of S7 315-2PN/DP CPU as a controller,this system adopts distributed structure using the advanced fieldbus,the wiring is very simple,running is stable,and maintenance is convenient.PC utilizes industrial control computer with WinCC as its monitoring software,thus achieving the design of interface,and connects PLC with industrial Ethernet.Physical analysis is done on the remelting rate control object of vacuum electroslag furnace and mathematical model of control object is established.And remelting rate detection process is handled with filtering.Considering that nonlinear,time-varying,hysteresis exist in remelting rate control system of vacuum electroslag furnace,generalized predictive controller is designed in the Simulink.Through the simulation of this method and comparison between generalized predictive control and conventional PID control,it proved that generalized predictive control is superior in rate,laying a solid foundation for its application.