Design And Realization Of The Control System Of Vacuum Self-consuming Arc Furnace

Vacuum consumable electric arc furnace is the main smelting equipment of titanium,steel and related alloys at present.The research and design of an electric arc furnace is a very complicated subject considering the stringent requirements for the smelting environment and control of related metals,the complexity of equipment structure and process,and the difficulty of control strategy implementation.The whole process of production can be controlled and improved by means of automatic control techniques containing special policies.Considering the advanced application technology in foreign countries,the research and design of the electric arc furnace control system adapted to the specific engineering situation will play a significant role in improving the efficiency of metal processing.On the basis of studying and comparing the relevant knowledge in the same field,this paper firstly summarizes the research status and trend of different aspects in the future.Taking smelting mechanism as the core,the composition of equipment,key process nodes and their control characteristics are described in detail,and the relationship between parameters is combed out.The principle of reversible speed regulation is thoroughly analyzed and the mathematical model of dc motor is established.Based on PID control algorithm and engineering design method,three closed-loop arc pressure control schemes are designed step by step in detail.Variable parameter PID is selected to control the melting rate in different melting stages.The interference between the above two control modes due to the coupling of voltage and current is analyzed.Considering the actual situation,the Matlab/Simulink platform is used to build and simulate the three-closed-loop control scheme,and the results show that it has good tracking performance.Combined with the technical renovation project of Bao Ti group electric arc furnace,the control system of vacuum consumable electric arc furnace takes s7-300 PLC as the control core and combines digital dc governor,upper computer and industrial bus to form the hardware basis.The hardware framework of the core arc voltage system is built,the communication network architecture is designed,and relevant parameters and specific configuration methods are given.Then,on the basis of the technological process,the main program and the software algorithm of the subsystem are designed respectively.In the Intouch configuration software,the communication with the lower computer is established and the monitoring function of the system is developed.The control system has realized high precision,centralized and digital control.Finally,through the performance test of the equipment in the project,the feasibility of the research design in this paper was verified,and the goal of high performance of the control system was achieved.