Variable Air Volume Air Conditioning System Control Features Simulation Study

The method combining fuzzy controller with PID and its successful application in controlling the indoor temperature of VAV air conditioning are introduced. Fuzzy control is introduced in the control process, and by using it and according to the dynamic characteristics and behavior of the system, on-line adjustment is carried out to the PID control. the method has higher precision, smaller overshoot and stronger robustness, compared with common PID controller.Nowadays, the study about controlling just exists in the primary phase. What has been done to carry out profound and systematic research on fuzzy control of the air-conditioning system is too little, basically resulting blank. As a complex thermodynamic system, VAV system has many disturbances and is not easy to calculate its parameters. In order to satisfy the needs to control effectively and save energy efficiently, this paper introduces a Fuzzy-PID control algorithm. So as to tackle the contradiction between the stability of the control system and gain good performance. Strengthen the adaptability of the system to some unstable factors. Simulating the hypothesis in MATLAB environment. The result indicates that when the parameters changes, this control system has good effects and can save energy. So the research of it has high significance. it offers a reference method for the practical application in future and certain reference value for further research and design of the air-output changing air-conditioning systemThis paper mainly includes four parts.Firstly, from the viewpoint of the elementary problems such as the VAV system's principal, classification, domestic actuality, existent matters and the relevant solving ways, the VAV BOX, which is the kernel part of the VAV system, is studied with emphasis in the ways pf operating principal, control modes and so on.Next, Variable Air Volume (VAV) air conditioning system is superior to other air condition system for its economic and flexible performance and has become the main stays of fir conditioning system. But as a complex thermodynamic system, VAV system has many disturbances and is not easy to calculate its parameters. With the development of computer science and control theory, many new intelligent control theories come into being, In order to satisfy the needs to control effectively and save energy efficiently, this paper introduces a Fuzzy-PID control algorithm.Afterwards, The method combining fuzzy controller with PID and its successful application in controlling the indoor temperature of VAV air conditioning are introduced.Finally, The simulative result indicates that, when conditions change, the method has higher precision, smaller overshoot and stronger robustness, compared with common PID controller. The result indicates that when the parameters changes, this control system has good effects and save energy.