Abstract: In order to solve the problems such as numerous variables, serious coupling, large time delay and uncertain perturbations in variable air volume air conditioning, a decoupling PID control strategy based on analytic method is proposed. Models of the two coupling loops, air supply temperature and indoor temperature, are established, and also establishes the suitable desired closed-loop transfer function matrix. Thus the ideal expression form of decoupling controller matrix can be derived. Thereafter it is converted into PID form through Routh method for reducing order and one order Pade approximation. Performance requirements such as stability and robust stability are satisfied through adjusting the only regulatory variable according to amplitude frequency curves of spectral radius. Thereby the specific value of each parameter can be obtained. The results show that decoupling strategy based on analytic method can not only eliminate the coupling effect completely, but also has smoother tracking performance than that based on feed forward compensation, and less affected by uncertain perturbations.

Key words: variable air volume air conditioning, analytic method, decoupling, PID control

摘要： 为了解决变风量空调中变量众多、耦合严重、延迟时间大、易出现不确定摄动等问题，提出了一种基于解析法的PID解耦控制策略。通过建立送风温度与室内温度两支耦合回路模型，并构建合适的期望闭环传函阵，推导出解耦控制器矩阵的理想表述形式。利用劳斯降阶与一阶帕德近似将其转换成PID形式，通过改变唯一的调节变量并根据谱半径幅频曲线来满足稳定性与鲁棒稳定性等要求，从而获得各参数的具体数值。结果表明，相比于前馈补偿PID法，基于解析法的解耦策略不仅能够完全消除两支回路间的耦合效应，还具有更平稳的跟踪性能，受不确定摄动的影响更小。

关键词: 变风量空调, 解析法, 解耦, PID控制