Advanced Control And Simulation For VAV Of Airport Terminal

From the view point of saving energy and improving the indoor air quality, variable air volume (VAV) air-conditioning system is one effective type of the heating, ventilating and air-conditioning (HVAC) control systems, which is the important part of intelligent building energy management control (EMC) system. So, it is to control the VAV air-conditioning system effectively.The background of the paper is intelligent building management system of Beijing Capital International Airport Expansion Project (T3). The VAV air-conditioning system of the new built terminal for domestic passengers (T3A) is studied in the paper. On the basis of learning the project structure, the structure and control theory of the VAV air-conditioning system are analyzed and the mathematical models of correlative subsystems are developed by system identification and mechanism modeling.For plant with large time delay in the system, Smith predictive control is used in the paper. The dynamical characteristic of system is predicted and compensated by adding Smith predictor in the control loop, so that the output delayed is pre-displayed on regulator to reduce the overshoot and regulation-process. The influence from system interference is not removed completely with Smith predictive control yet, to solve the problem the Smith predictive control is improved by combining with Feed-Forward Compensation. The character of regulating in time is used in FFC-Smith control to reduce the interference influencing to output through the system feedback, then the system is in stable condition. At last, from the contrast of the simulation curve for the two control strategy, the FFC-Smith control is superior to the Smith control in many performances and the result is satisfactory.