The Application Of Pole-placement Control In Variable Air Volume Air-conditioning System

Of all the Building Automation Systems (BAS), heating, ventilating and air-conditioning (HVAC) systems ate most important from the viewpoint of saving energy and improving the quality of the indoor environment. Therefore, adopting efficient control strategies lor air-conditioning plays a vital role in developing improved energy management control (EMC) systems for intelligent buildings (IB). Nowadays, VAV air-conditioning system has gradually become mostpopular in China and abroad because of its signifcant energy saving. However, since VAV system is multivariable,strongty counted, nonlinear and time variant, its design, performance and management are more difficult than CAV system's. It's an important reason that Iimits the VAV system for agreater use.As modeling and designing its controller for each loop whose interaction is significant, the stablility of the system must be considered According to this condition. the paper takes the air transmission unit as the object for studying And has concluded a control plan by pole-placement. Firstly, the paper models the multivariable discrete state-space model of the air transmission unit by the lab method, using multi-dimensional inverse M series as input stimulus signal. Secondly, the paper analyses stability, control-ability and observe-ability of the model, designs the controller based on pole-placement and simulates using MATLAB software.Simulation of the try are pleased. And they have proved the plan's validity. Also,the paper has provided a program for the system's data logging and control. It is designed by Visual Basic. The program exchanges data with the system of Metasys in the mode of VB-DDE-METASYS.And it has fine operating interface.