供暖、通风和空调（HVAC）系统在动态负载下运行，可能会出现不可预测的干扰。相对较小的扰动会极大地影响某些子系统的性能，例如冷却盘管控制阀。冷却盘管控制阀的操作错误有可能与其他子系统的错误复合，并恶化空气处理机组（AHU）的性能。在许多情况下，控制系统都是非线性的高阶系统，这降低了传统控制方法下系统稳定的可能性。本文的目的是在非线性冷却盘管控制系统上，通过与传统的比例积分（PI）控制进行比较，对串级控制的冷却盘管控制阀性能进行实验评估。 在本文中，首先使用参考输入的阶跃变化（即送风温度设定点阶跃变化）和干扰输入的阶跃变化（如冷冻水回路压差（DP）阶跃变化）来比较两种控制的性能。主要的测试标准是操作误差，以平均积分平方误差（mISE）表示。在比较两种控制方法时，还考虑了系统稳定性、稳定时间和干扰抑制。因此，当阀门系统发生压力中断时，串级控制最有效。例如，当DP降低5 psi（27）时，观察到串级控制的最大误差为0.46°F，单回路控制的最大误差为0.95°F。 而串级控制中的mISE仅为单回路mISE的5.5%。此外，串级控制的mISE值约为参考阶跃变化试验单回路mISE值的42%。引用:2020年虚拟会议论文

Heating, Ventilation, and Air Conditioning (HVAC) systems operate at dynamic loads and may present unpredictable disturbances. Relativelyminor disturbances can greatly affect the performance of certain subsystems, such as the cooling coil control valve. The operating error of the cooling coilcontrol valve has the potential to compound with error from other subsystems and deteriorate the performance of the air handling unit (AHU). In manycases, the control systems are nonlinear and of high order, which reduces the likelihood of system stability with conventional control approaches. The objectiveof this paper is to experimentally evaluate the cooling coil control valve performance of cascade control by comparing it with a conventional Proportional-Integral (PI) control, on a nonlinear cooling coil control system. In the paper, the performances of both controls were compared first using a step change inreference input, i.e. supply air temperature setpoint step change and a step change in disturbance input, such as chilled water loop differential pressure (DP)step change. The primary testing criterion is the operating error, in terms of mean integral square error (mISE). System stability, settling time, anddisturbance rejection are also considered in the comparison of the two control approaches. As a result, the cascade control is found to be the most effectivewhen the valve system experiences pressure interruptions. For example, a maximum error of 0.46 °F for the cascade control and 0.95 °F for the single loopcontrol were observed when the DP is reduced by 5 psi (27.8% of the operation value), while the mISE in the cascade control was only 5.5% of the singleloop mISE. In addition, the mISE value of the cascade control is approximately 42% of the single loop mISE value for reference step change test.