Abstract: As for the evaporator superheat with the characteristics of large time delay, this paper proposes predictive control approach. Based on the input and output data of the object to identify the object dynamic model of the evaporator superheat, it predicts the next time output of the system using the prediction model based on Dynamic Matrix Control（DMC）, to control the superheat requirements in the target range. The experimental results show that using the control method of DMC, the system runs stable, has strong anti-interference. Compared with conventional PID control, the DMC control runs more accurately, and can get better control effect.

Key words: evaporator superheat, time-delay, predictive control, Dynamic Matrix Control（DMC）, step response model

摘要： 针对蒸发器过热度具有大纯时延的特点，提出采用预测控制的方法。根据对象的输入输出数据辨识出蒸发器过热度对象的动态模型，再根据动态矩阵控制（DMC）的预测模型预测出系统未来时刻的输出，从而达到将过热度控制在目标范围内的要求。实验结果表明，采用DMC的控制方法，系统运行稳定，抗干扰性强，与常规PID控制相比，DMC的控制精度高，控制效果更佳。

关键词: 蒸发器过热度, 大纯时延, 预测控制, 动态矩阵控制, 阶跃响应模型