Design And Research Of The Control System Of Vacuum Induction Furnaces

Vacuum induction furnaces are important melting equipment, which are mostly used to produce Ni/Co based high temperature alloys, Ti alloys, stainless steels, super high-strength steels and special alloy materials. As an important part in vacuum induction melting (VIM), the automatic control system has a direct influence on the quality and output of products. At present, for the laggard technique and the low-level automatization, the process control of VIM has restricted the development of vacuum induction furnaces severely. Therefore, it has theoretical and practical significance to research the process control technique to ensure stable operation of smelting process.The content of the thesis comes from the research project of "study of the control system of vacuum induction furnaces". On the basis of analyzing speciality of VIM's power supply control system, computer control system based on fuzzy PID control is designed. The thesis compares control effect of fuzzy PID controller with that of general PID controller by simulation experiment using MATLAB. Comparative result indicates that fuzzy PID controller's control performance is better.A mixture optimization method is used for the mixture problem of VIM, which is described as linear programming model aiming at the lowest cost of raw material. Simplex method is used to solve the model in computer arithmetics. The simulation example of mixture calculation indicates that the method improves efficiency and veracity of the mixture calculation, and saves the cost of melting production.