空调系统通常是非线性的，线性化对象模型中的增益常数、时间常数和死区时间等参数受送风量（或控制输入）的强烈影响。如果参数在送风量过小的区域过大，可能会出现不稳定的控制特性。当参数因工作点（即控制输入和干扰输入函数给出的平衡点）的变化而变化时，比例调节的主要问题之一- 积分微分（PID）控制器具有稳定性。为了避免这种不稳定性，本文提出了一种用于变风量（VAV）系统温度控制的分散控制器（两个单回路控制器）。分散式控制器旨在将供气气流速率恢复到所需的数值。当送风量小于所需量时，除集中（主）控制器外，分散控制器将关闭。温度控制方式可由分散控制改为集中控制。 典型的日常仿真结果显示了分散控制器的控制性能。引文:ASHRAE Transactions，第117卷，第2部分，魁北克省蒙特利尔

An air-conditioning system is generally nonlinear, and the parameters such as the gain constant, the time constant, and the deadtime in a linearized plant model are strongly affected by the supply airflow rates (or a control input). Unstable control characteristics may occur if the parameters are excessively large in the region of too-small supply airflow rates. When the parameters vary due to changes in the operating points (that is, an equilibrium point given by a function of control input and disturbance inputs), one of the main issues in tuning proportional-integral-derivative (PID) controllers is stability. To avoid such instability, decentralized controllers (two single-loop controllers) for temperature control in a variable- air-volume (VAV) system are presented. A decentralized controller is designed to bring the supply airflow rates back to some desired amounts. When the supply airflow rates become smaller than the necessary amounts, the decentralized controllers are shut down except the centralized (primary) controller. The temperature control mode can be changed from the decentralized controller to the centralized one. Typical daily simulation results showing the control performance of the decentralized controllers are presented.