Research On Air Energy Heat Pump Process Control System Based On Smith-fuzzy PID

In response to the national policy of "coal to electricity",air energy heat pump has become a new favorite because of its cleanness,environmental protection,energy saving and safety,replacing the main force of coal-fired heating in the north and occupying the market raPIDly.Through the introduction of the origin of air energy heat pump and the analysis of its market share,it is found that the market potential of air energy heat pump is huge.With the development of society,the structure of air energy heat pump control system is becoming more and more complex,the components and parts are increasing,and the characteristics of nonlinear,time-varying,large inertia and large delay,time-varying of main steam temperature are more prominent,which makes the control system more Complex.PID control system is widely used in modern air energy heat pump plants,but it is difficult to achieve the ideal control effect.Therefore,it is necessary to study the control system of air energy heat pump and improve the control mode.Compared with the current mainstream intelligent control methods,the fuzzy algorithm is suitable for the temperature control of air energy heat pump,and Smith delay compensation is proposed according to the time delay characteristics of the system.The structure and composition of air energy heat pump,the distribution diagram of air energy heat pump system,the static and dynamic characteristics of each component of the system in the state of refrigeration and heating,and the basic principle of inverse Carnot cycle are studied.Combined with the analysis,the simulation model is established by two-point method,the PID control method is studied,the fuzzy algorithm is introduced,the fuzzy PID control algorithm structure is designed,and the fuzzy rules are selected;the fuzzy controller fuzzification and de fuzzification methods are determined;the parameters of the fuzzy controller are determined;a feasible fuzzy PID control scheme is proposed,based on the original fuzzy control scheme An improved Smith predictive compensation control algorithm is proposed.According to the deficiency of fuzzy PID,the Smith predictive compensation controller is designed.Combined with the controller structure chart and algorithm analysis,the advantages of the scheme are proved.Through the analysis of simulation results,it is proved that Smith fuzzy PID has the advantages of fast response,small overshoot and fast regulation,etc.because of no lag effect,compared with PID and fuzzy PID.After the random disturbance appears in the system,the oscillation amplitude of Smith fuzzy PID is much smaller than that of PID and fuzzy PID,and the stability is restored quickly.The comparison results show that the design is feasible.