基于模糊PID控制的锅炉汽包水位控制系统的研究.doc

摘 要 本文首先分析了影响汽包水位的各种干扰因素，并对汽包水位的动、静态特性进行分析。介绍了传统的PID控制方式，由于锅炉汽包水位控制系统的调节器的输入端常加有三个不确定的输入量，极易引起水位控制偏差。所以本文提出了两种消除水位偏差的方法：辅助信号自消方法和辅助信号对消方法。采用辅助信号蒸汽流量和给水流量对消方法消除水位偏差，根据锅炉汽包水位控制实际要求，采用模糊PID控制，用MATLAB中的SIMULINK仿真工具箱设计了二输入单输出模糊控制器对锅炉汽包水位进行在给定值下仿真。并用常规PID和模糊PIDF方法去控制汽包液位，对比两种控制策略下的防真图像，仿真图像表明后者的抗干扰能力和鲁棒性更好，可以保证水位的稳定，并且能有效解决用常规PID无法解决的“虚假液位”问题。最后简单介绍几种由汽包水位测量方法及测量误差带来影响、及消除方法，通过现场实例解决了汽包水位测量不准的问题，减少了由于水位测量误差给汽包水位带来的不利影响。 关键词：汽包水位、虚假液位、PID控制、模糊PID控制、水位测量误差 Abstract This article first analyzes the impact of the drum water level of the various interfering factors,and drum water level of the dynamic and static analysis features.Introduced the traditional PID control,due to the boiler drum water level control system input regulator has three regular increase of the input uncertainty is very easy to control the deviation caused by the water level.Therefore,this paper two methods to eliminate the water level deviation: auxiliary signal from the elimination method and auxiliary signal cancellation method. The use of auxiliary steam flow signal and water flow rate on the elimination method to eliminate the water level deviation of the boiler drum water level control in accordance with practical requirements, the use of fuzzy PID control, the use of MATLAB simulation toolbox SIMULINK design two-input single-output fuzzy controller on the boiler drum the water level to the next value in a given simulation. Using conventional PID and fuzzy control approach to PIDF drum level,compared to two control strategies of anti-real images, simulation images show that the latters anti-interference ability and robustness better, can guarantee the stability of the water level, and can effectively solution can not be resolved with conventional PID false level problem. Finally, a brief introduction by the drum water level of several measurement methods and about the impact of measurement error, and the elimination method, through on-site example of the drum water level measurement solution to the