智能PID控制在中央空调冷水系统中的仿真研究

Research of Intelligent PID Control in the Central Air-conditioning Chilled Water System

针对中央空调冷水系统是典型的非线性、大滞后、时变性、大惯性及强耦合的复杂系统,其中参数未知或变化缓慢;带有延时或随机干扰,无法获得较为精确的数学模型或模型非常粗糙。常规PID控制器因其对精确模型的依赖性,且难以在线进行PID参数整定,故难以达到满意的控制效果。文章在传统PID的基础上,结合模糊控制原理,提出了基于模糊推理方法对PID控制器参数进行整定,设计出相应的模糊PID控制器。最后,运用MATLAB仿真研究表明,模糊自整定PID控制器既具有常规PID高精度的优点,又具有模糊控制快速、适应性强的特点,使被控对象具有良好的动、稳态特性。

Aiming at that central air conditioning chilled water system is a typical nonlinear,large delay,time variability,large inertia and strong coupling of complex systems,and in which unknown parameters,or changes slowly,and also with the delay or random interference,a more accurate mathematical model can not be got.Because of its dependence on the accurate model,and difficult to tune PID parameters,Conventional PID controller is difficult to achieve satisfactory control effect.Based on fuzzy reasoning,a method tuning PID controller parameters is proposed in this article,and the corresponding fuzzy PID controller is designed.Finally,the MATLAB simulation shows that the fuzzy self-tuning PID controller has both the advantages of high precision in conventional PID,and the characteristics of quick,strong adaptability in fuzzy control.The controlled object has a good dynamic and steady state characteristics.