Computer-Aided Design & Simulation Analysis Of Building Environment Control System Based On MATLAB/Simulink

In recent years, HVAC automation developped rapidly and all kinds of HVAC systems with autocontrol have been throughout the country. But in most of these systems, the running performance & energy saving effect was not satisfying. The reason that caused these problems above mentioned is: a. Experiences are used for designing autocontrol system of HVAC, for other aided-design means is poor; b. That the control strategy & parameter value is whether proper or not be usually judged according to the running performance on the spot only after the system is finished. If some fault is found, it is only adjusted and modified locally, that made it difficult to realize optimization control; c. If there is trouble with the system, HVAC technicians must fall back on control professional since there isn't theoretic analysis method for HVAC control system. But the control professional can not rapidly, thoroughly, perfectly solve the problem, because of not familiar with technical schedule.Aimed at the practical problem in HVAC control field above described, this paper brought forward to apply a autocontrol system analysis-design software namely MATLAB/Simulink, which is prevalent in control field, to design and analysis of HVAC autocontrol systems. By means of the Control System Tools supplied by MATLAB, this paper analysised stability, dynamic performance and steady-state performance of HVAC control systems and studied how to ascertain and optimize control parameter value such as PID control through simulation in Simulink all sidely. All the work is based on the Time Domain Aanalysis and Root Locus method in classical control theory. It has been done also to analysis properties of controlled objects in HVAC field and to establish their mathematical model by using with MATLAB function in this paper. At last by a comprehensive experiment that a room temperature is controlled, it is shown that this method applying MATLAB/Simulink to analysis and design of HVAC control system is convenient, rapid, and efficient, and that the results of design-analysis by means of this approach has high practicability and referential value.