Study On Predictive And Sliding Mode Control Of Heating System

Urban central heating has become a major form of winter heating in northern China.Its heat cost a lot while heating system running.The controlling of the heating system,the heating system in the assurance of quality heating and saving energy have become the major issues to be resolved.The majority of our central heating system operation and management and control technology is not mature yet.This problem due to the heating process with a nonlinear,time-varying delay,uncertain characteristics.Modeling accuracy is difficult to be protected.The traditional control methods is difficult to adapt to these circumstances.Rely mainly on empirical data to which lack of scientific,lower level of automation.The district heating generally fail to achieve control requirements.The heat transfer station is the most important part among of heating company heat source,heat pipe,heat transfer station and heat users in the heating system.therefore,one heating transfer station in one district in the city of Shenyang is used for studying to meet the residential property owners hot demand,to meet the compliance requirements of the indoor temperature.The heating flow of coming side of network is used as the part of controlling,the heating flow of the outgoing side of network is used as the controlled object in the station automatic controlling.The ultimate goal of controlling is to make the outgoing side of network to achieve the desired supply temperature.A precise mathematical model is an important basis for the heating system analysis and control.In this paper,the mechanism analysis method is used to determine the system category,thenthe thermal station site heating is measured,finally,the multi-particle swarm identification method is used of to establish the specific model of the heating system,providing a mathematical foundation for heating system predictive control research.The modeling method of the identification of the heating system is better able to meet the application requirements is proved through simulation.Control of heat transfer station is still using the traditional method of PID,but the effect is not very good control, because P1D control is usually used in linear system, and the heating system is a very complicated controlled object, the system itself has nonlinear; Affected by external interference, it often presents a non-stationary system, through the sliding mode controlling and predictive controlling,the method not only solves the problems of predictive controlling which is difficult to guarantee the stability but also reduces the chattering problem of pure sliding mode controlling, The simulation shows that the method of heating system control can play a good role, and has good tracking performance and robustness. In the outside interference, curve does not have any too big wave motion,but the use of PID controlling have the larger overshoot and a long period of adjusting time, so once again proved the superiority of the sliding mode predictive control.