青啤二厂发酵计改工程自动化控制系统由上位机操作站、下位机控制器并配以一次测量仪表及执行机构构成。在发酵控制室设置上位操作站3 套，下位控制器采用德国西门子S7 系列可编程序控制器。关键词：发酵系统；PID；变频恒压控制；模糊控制Abstract: The auto-control system of reconstruction of zymotic project in the Second Qingdao Beer Factory consists of upper manipulator, lower controller, metrical meter and administering unit as well. Three manipulators are set up in zymotic control room. Programmable controllers produced by Simens of Germany are used as lower controllers.Key Words: Zymotic System, PID, frequency conversion and unvarying pressure control,fuzzy control