Control System Design Study On Electroslag Furnace For Slag Ingots And Control Scheme For Crystal's Level

With the rapid development of our state economy, many various steels are widely needed. Typical cases in point are high-class die steel,boiler steel,nuclear tube plate steel which are brought into full play in all walks of life. Compared with common steels,steels made by electroslag remelting possess a higher transverse plasticity and toughness. Pieces of equipment of electroslag furnace for slab ingots,characteristics of obvious economy benefits, are relatively simple, have low investments and dominants the prevalence in the high technological market.The background of the thesis is based on the 40-Ton ESCC computer automatic control system in some steel mill.The historic, present state and perspective of control techniques of Electroslag furnace are summarized on the basis of consulting a great deal of documentation. According to smelting characteristic of the control system demands, an advanced computer control system is developed based on PLC controller. A distributed computer control system is designed based on the PROFIBUS-DP. It controls the entire smelting process by using Siemens S7-300 and ET200S series PLC. Siemens's WinCC configuration software is used to complete monitoring software configuration and realizes the field data real-time recorded and the monitoring. The dynamic operation picture style of smelting time, recording inquiry, and read-write parameter are designed as well.Crystal's level control plays an important part in the dynamic crystal system.The level fluctuation could affect the quality of the steel and even cause the steel water to leak and overflow. So the level must be controlled within a reasonable range.However,Crystal's level system has the characteristics of the non-linear and time variability. There are many unsure disturbing factors in this system. Therefore the precise mathematical model can not be proposed. Crystal's level control on Artificial neural network is studied in this paper. Based on the neural network, the theory of compound PID control is put forward. Comparison of between dynamic and static performance,disturbance-rejection,and the compound control and the PID control are simulated. All of these will make a strong foundation for the future.