Automatic Control System Of The Coal Sales Railway Loading Station

Coal loading system is an essential part of the coal sales. The rapid, safe and efficient loading of coal in accordance with the demand is great significance to coal production enterprises. In this paper, the present situation of loading system at home and abroad has been described. And the advantages and disadvantages of various loading systems have been analyzed. According to the theory of variable frequency control and internal model control, a coal loading station automatic control system was designed by selecting Jiangzhuang Mining Group loading system as the background.The coal loading station automatic control system combined PLC control technology, network communication technology, sensor technology, frequency control, PID control strategy based on internal model principle. It could realize two loading modes of automatic control and manual control. In this thesis, the research work was carried out in the following aspects:(1)The framework of the automatic control system was designed. The design and selection of PLC hardware system, module selection and type of sensor equipment were completed. The electrical part design of the controlled equipment was completed. By using the dynamic electronic track scale to realize the dynamic weighing of train loading quantity. By using photoelectric switches to realize the loaction detection of train carriages. By using material level meter to realize the detection of coal height of loading carriage. The control system adopted Siemens S7-300 series PLC as the control program core, by using Ethernet technology, PROFIBUS-DP technology to achieve communication network construction.(2)Combined the traditional PID control strategy with the internal model control principle, the loading model was setted up according to the loading height, so as to realize the control of the winch traction speed. In order to realize the precise coordination of loading capacity and train traction speed, the mathematical model of discharge gate was established. The PID controller based on internal model principle was designed, and the parameter setting was realized. The controller adjusted the gate opening and closing degree, in order to achieve continuous and stable loading control of train.(3)The system programming design was divided into PLC control program design and upper computer monitoring interface design. PLC control program used STEP7 V13 programming software based on the control strategy to achieve the hardware configuration of the control system, parameter settings and the realization of the function of the program block. By using touch screen as upper computer. MCGS software was used to design the upper computer interface, monitor and control the operation of the equipment.The field operation showed that the control system was reasonable. It could effectively improve the efficiency and accuracy of the coal loading, and saving the cost of production. It had certain application value and significance.