Study On The Electrode Control System Of Vacuum Arc Furnace

Vacuum Arc Furnace is also named Vacuum Arc Reemitting Furnace (VAR). It is the key equipment for producing high quality alloy, for example, INCONEL718. In the circumstance of high vacuum, steel ingot can be smelted again under the action of electric arc, uniform crystallization can be formed. After this the mechanic characteristics of the alloy is improved greatly. At present China is one of the largest producer and consumer in the Alloy scopes. But the key equipment: Vacuum Arc Furnace is also depends on import. So Vacuum Arc Furnace's self-develop and corresponding control system has become more important.On the basis of participating in the system design and debug of the 2T Vacuum Arc Furnace which is cooperated with BAOJI Institute of Rare Metal Equipments in FUSHUN SPECIAL STEEL CO., Ltd. This paper concludes the practice and work. According to the former research and the fact, the practices I do are as flows:This dissertation carries its study on Vacuum Arc Furnace, learning related domains, concluding the application of the control technique in industry. It describes the primary module of the Vacuum Arc Furnace. Then it shows the technical principle and the parameter's change during the whole melting process. It analyzes the characteristic of the Arc during the melting, figures out the relationship between the arc length and arc voltage, arc current according to the former research and the fact. It accounts the character of every tache in the control system, figures out the model of the control system and it also simulates the syatem step responds in SIMULINK of MATLAB.It enumerates several control arithmetics according to the character of the object, first, it emulates these control arithmetics using SIMULINK, and choose the Gain Adaptive PID Control arithmetic. Then it illuminates the data processing of the data transfer, arc volt controlling, calculating and controlling melting rate. It also finishes the main program use PLC.It chooses the SIMATIC S7 400 PLC bases on the requirement of the Vacuum Arc Furnace's control system. It figures out the I/O statistic and the sensors number, then figure the hardware of the control system. It also finishes the development of HMI using WinCC, which especially improves the operation.