Design And Implementation Of Control System For Electron Beam Melting Furnace

Electron Beam Melting Furnace has become the main device for melting refractory metal and high temperature alloy. There are some problems of short service life, unstable emission electron and low automation of electron gun in domestic. The performance of the devices is required higher and higher with the increase dosage of rare metal new material and alloy materials in the field of military and industrial. So it has a profound significance to develop high performance automatic control system for the equipment.In order to satisfy the require of the vacuum degree,the smelting power,the high control accuracy of feed and pull an ingot, Dissertation the good stability and the performance of real time. This paper has analysis the design of each controlling unit based on the peculiar procedure of electronic beam smelting. We utilized some hardware, such as PLC, industry controlling computer, intelligent control component and exchange the servo control electric motor, to realize five functions of the electron beam smelting control, including automation evacuation of vacuum system, the three closed loop and cascade control of melting power source system, automation control of feedstock and discharging system, automation control of deflection and focusing system, and on-line monitoring of the system.Dissertation designed a three closed loop and cascade control for direct-current power source system. PI control strategy used in the inside loop system, the second loop system and the outside loop system improve the stability of the whole system, overcome the delay and errors of simple digital PI control, and solve the problem of melting speed constant. In the meantime, Dissertation designed and debugged the system hardware and the software.Through the actual test and inspection in the process of real production, all control indicators fully meet the requirements of electron beam melting production process, and even some indicators exceed expectations before modification, such as ingot yield and deviation of electron beams current. The results show that the system has higher performance of control accuracy, reliability, and real-time.