The Design And Development Of The Electric Control System For Tobacco Redrying Machines

Tobacco redrying is a re-curing process after the tobacco drying for the first time, which has direct impact on the production of cigarette industries. This thesis designs two separate control systems, applying the PLC control as chief means and the UDC control as stand-by.By analyzing the function of control systems, the configuration of the control systems is determined to control parameters in the production process, in which thermocouples, humidity sensors and pressure sensors are used, the PLC from Siemens and UDCs are utilized, and the control of the PID adjustment is adopted. The control systems make use of the currently popular Profibus, by which the exchange of data between inverters and PLC is achieved, thus the cost can be saved, and the system extension will not be confined by conditions on the spot.With a friendly man-machine interface, an operator can monitor and control the running of the machine and make real-time adjustment on the spot by every monitoring and control interface.The simulation running of the machine was performed on the spot by using the S7-PLC SIM Emulation Software and the ProTool/ Pro RUN running Software, performability of the PLC Program was tested, the ratio and integral parameters of the PID adjustment were estimated in advance, and the adjustment schedule of the control systems on the spot was quickened.