Low-e Glass Production Line Distributed Control System

In recent years,as China's construction boom and the deeply rooted concept of energy saving, Low-E glass, for its good energy-saving effect of buildings, become the darling of construction, and market demand is huge. Magnetron sputtering vacuum coating production line as the current mainstream Low-E glass production facilities, has wider application and development in China. Over the years, the domestic Low-E glass vacuum magnetron sputtering production line is mainly dependent on imports, which greatly increased the cost of doing business, and limited the market prospects of Low-E glass.On the basis of in-depth study of the characteristics of vacuum magnetron sputtering process, the structural specialties and workflow of coating production line were analyzed. According to the characteristics of large number of devices, complex control logic,many control parameters,complex electromagnetic environment in glass coating process, the Low-E glass production line control system based on DCS frame was reasearched. The main research and development contents were as follows:1.After analyzing the vacuum extraction system of Low-E glass coating production line, a three pump-based modular pumping unit has been designed,and its electrical control circuit and control program flow diagram were given. In addition,vacuum testing equipment has also been analyzed. After analyzing the structure and working principle of the DC and AC sputtering power supply,the paper also designed the flow control system of process gas and the PEM monitoring system of sputtering gas discharge.2.Based on Low-E glass coating production line structural features, the production line drive control system was designed,and the control network topology was given. Field-station transmission system used PMSM servo system,and there was a analysis about the vector control strategy. The transmit of glasses between differert stations, required precise synchronization performance among moters. Therefore, a master-slave coupling vector control strategy was used to realize the synchronized control between different moters.3. Through the analysis of the coating production line, the paper designed a glass-coating production line DCS,which used double block S7-416 PLC as its control core.Under the guidance of the modular idea, we used STEP 7 V5.4 software platform for the preparation of lower control procedures.In the WinCC control system development environment, the paper established the human-machine interface of glass-coating production line DCS,to realize real-time and accurate control of various working conditions and achieve a Low-E glass production process automation and visualization operation.Production practice has shown that the coating production line control system is structured, full-featured, reliable, easy to maintain. It was an open system, easy to upgrade and transform, and has met the desired design goals.