Study On The Construction Of SCADA System And Control Strategy For Central Heating

In recent years,with the rapid development of national economy and the gradual improvement of people’s living standard,the market scale of urban central heating industry in China has been expanding.At present,the domestic central heating system mainly has the following two problems: first,the thermal substations are scattered over every corner of the city,the single traditional control methods are not only time-consuming and laborious,but difficult for the whole network operating parameters to conduct a comprehensive monitoring;second,the development of automatic control technology of the domestic central heating system is not mature enough,the control strategy and regulation the method is relatively backward.This paper aims to construct a complete SCADA system for automatic monitoring of the network of central heating system,and achieves the centralized management of scale and information.The control strategy is optimized to improve the control accuracy of the thermal substation control system.In this paper,heating quality and allocation of energy are further improved in the central heating system from two perspectives: optimal management and optimal control.Through the analysis of the mechanism,the main channel model and the coupling channel model of the quality and quantity channels in the heating process are established.with soaring method and least square method for parameter identification of the model,Finally,the coupling model of the quality-adjust and quantity-adjust is established.The heating control system has the characteristics of time-varying,nonlinear,large time delay,strong coupling and so on,in order to improve the control performance,the heat transfer station is used as the object,an expert fuzzy PID controller is designed based on the above model.The controller is mainly composed of PID fuzzy control and expert control of two parts,Expert control is used as the coordination level,according to the database and knowledge base,Quantization factor of fuzzy PID controller is optimized by inference machine.The simulation results show that the controller has short adjustment time and low overshoot.The PLC program written by TIA Portal software is applied to verify the effect of Industrial site,and the results show that the control effect is stable.In this paper,the SCADA system as the structure of the central heating system of automatic monitoring is composed of three levels: monitoring layer,control layer and device layer,Through the functional requirements analysis,the hardware system,software system and communication system of the monitoring layer,control layer and equipment layer are designed by turn.The software part mainly use Kingview as the PC software of the SCADA system for software development,and through the ODBC(open database connectivity),the Kingview get access to the SQL database.The application of this system has been in the field of thermal substation,and the system is stable and reliable.