基于自校正水泵模型的空调系统冷水泵压差前馈-反馈控制方法*
Feedforward-feedback control method based on self-calibrated pump model for chilled water pump of air conditioning systems
摘要：
在空调冷水系统运行过程中，冷水泵的运行频率需要根据实时系统工况进行调节。传统本地控制器一般使用PID反馈控制算法，基于被控变量（压差/温差）与设定值之间的偏差来调整水泵的运行频率。然而该算法的控制质量受PID参数整定准确性的影响较大。为解决该问题，提出了一种基于自校正水泵模型的空调系统冷水泵压差前馈-反馈控制方法。在被控变量和设定值出现较大偏差时，该方法可利用自校正的水泵扬程曲线与相似律快速计算出水泵应被调整至多大频率。使用某地铁站空调系统的实际运行数据作为模拟输入，对该控制方法下水泵的运行情况进行了模拟。结果显示，该方法的控制精度与基于单神经元的自适应增量式PID反馈控制基本一致，但该方法可简化对参数的整定工作，减少控制质量对参数整定的依赖。
Abstract：
During the operation of air conditioning chilled water systems, the frequency of a chilled water pump is typically adjusted with different working conditions. Conventional local controllers are mainly based on PID algorithm, which adjusts the pump frequency based on the feedback error between controlled variable (pressure difference/temperature difference) and the set point. The control quality of PID algorithm greatly relies on the tuning accuracy of PID parameters. To tackle the problem, proposes a feedforward-feedback control method based on self-calibrated pump model for chilled water pump of air conditioning systems. Using similarity and self-calibrated pump model, the proposed method can quickly calculate the target frequency when the controlled variable deviates from the set point. Validated by the simulation with measured data of an underground railway station air conditioning system as inputs, the control accuracy of the proposed method is close to the accuracy of self-tuned PID controller based on single neuron. Besides, the proposed method costs less manual labor to tune the PID parameters and reduces the dependence of control quality on parameter tuning.
Keywords:chilledwaterpump,pressuredifferencecontrol,feedforward-feedbackcontrol,self-calibratedpumpmodel,similarity