Decoupling Control Based On PID-ANN In Air Handling Units For Variable-Air-Volume Air-Conditioning System

With the improvement of the people' s life and the development of technology. The air-conditioning systems play a vital role in people' s life. But, because of the wide using of the air-conditioning systems, It' s energy waste became an importance problem. Therefore, adopting efficient control strategies for air-conditioning systems plays a vital role in developing improved energy management control (EMC) systems for intelligent buildings (IB). Nowadays, VAV air-conditioning system has gradually become most popular in China and abroad because of its significantly energy saving. However, since VAV system is multivariable, strongly coupled , nonlinear and time variant, its design, performance and management are more difficult than CAV system' s, and stable control of the entire VAV system is focused in particular in china.According to the conditions that the air handling units(AHU) has coupling variable and is difficult to operate stably, this paper presents PID -system based on artificial neural network(ANN) to decouple and control the plant. Firstly, the paper analyses the fundamental compose of the VAV; then analyses the principles and study algorithm of BP network .Modeling with neural network, and using serial-parallel identification structure, then get the dynamic model of AHU(2-input and 2-output). The paper presents a decoupling control strategythat based on PID-ANN system to decouple AHU. The author obtains the first weight of the PID-ANN off-line, and use the dynamic model of AHU to testify the feasibility of PID-ANN decoupling by simulation. Using the software and hardware based on the LonWorks technique, programming the decoupling control algorithm using VB, the author proves the feasibility of the decoupling control scheme based on PID-ANN system that applied to the VAV system. The results are satisfying.