Research And Design Of Coal Feeding Control System In Thermal Power Plant

As the electricity consumption of Chinese industrial increasing,many large domestic power plants have increased their own unit capacity,and result the increase of coal demand and average power and electricity consumption in various regions.Coal demand is also getting larger and larger,which requires that the coal feeding control system of the thermal power plant needs to complete the coal operation more stably and reliably.The automatic control method of the traditional coal feeding system can not meet the technical requirements of the current thermal power plant.In order to improve the performance of the control system,power plants should develop an intelligent coal feeding control system which is based on PLC.This system will improve the traditional coal feeding control system scheme more efficiently and improve the coal mining,It has a significant influence in Chinese industry.This paper focuses on the research and design of coal feeding control system by using a thermal power plant as the background.According to the requirements of the coal feeding control system,this paper firstly introduced the design of control system structure.Secondly,it determined the adjustment method of the frequency conversion speed and the measurement method of belt conveyor digital speed by using coal feeding system operation principle.Moreover,this paper applied the OPC technology and an advanced control method such as self-tuning fuzzy PID technology.Next,this article analyzes the theoretical methods of traditional PID control and fuzzy control of coal feeding system and the system of self-tuning fuzzy PID control method.Meanwhile,the transfer function of the coal feeding system is set up and combined with belt conveyor weighing model and belt drive motor because of the characteristics of time-varying and hysteresis of coal feeding control system.Then,this paper explained the traditional coal feeding PID control and self-tuning fuzzy PID control algorithm model by using the tool MATLAB/SIMULINK.Finally,according to the established coal feeding system transfer function pair,the effect of coal feeding system is simulated and analyzed.In conclusion,the finding of this paper conducted that under the self-tuning fuzzy PID control of the coal feeding system,the overshoot is small,the adjustment time is short,and the control effect is more stable.This method has a great important value of engineering application,it will improve the control precision and system intelligence level of coal transportation.Through the comprehensive research and analysis of the coal feeding control system,for satisfying the requirement of automation control and monitoring management of the coal feeding process,this system chose the reliable Siemens S7-200 series PLC as the main controller to control the field equipment and complete the signal acquisition and processing directly.The data processed by the PLC is transmitted to the upper computer configuration MCGS through the PC/PPI cable.In the upper computer,MCGS and MATLAB use OPC technology for data exchange,and use MCGS to complete Real-time monitoring of the status of the coal process.By completing the debugging and system communication test of the functions of various parts of the coal feeding control system,the automatic and intelligent control system of the coal feeding system of the thermal power plant is realized,which has certain practical application value.