锅炉汽包水位模糊控制系统的设计.docx

1、锅炉汽包水位模糊控制系统的设计摘要锅炉是典型的复杂热工系统，目前，中国各种类型的锅炉有几十万台，由于设备分散、管理不善或技术原因，使多数锅炉难以处于良好的工况，增加了 锅炉的燃料消耗，降低了效率。锅炉的建模与控制问题一直是人们关注的焦 点，而汽包水位是工业锅炉安全、稳定运行的重要指标，保证水位控制在给定 范围内，对于提高蒸汽品质、减少设备损耗和运行损耗、确保整个网络安全运 行具有重要意义。汽包水位的控制是锅炉控制的一个难点，目前，对汽包水位的控制大多采用常规PID控制方式，传统的常规PID控制方式是根据被控制对象的数学模型建立，由于锅炉水位系统存在非线性、不确定性、时滞和负荷干扰、非最小相位特

2、征等，其精确的数学模型往往无法获得，而且常规PID控制的参数是固定不变的，难以适应各种扰动及对象的变化，其控制效果往往难以满 足要求，控制效果不理想。模糊控制是建立在人工经验基础之上的，它能将熟练操作员的实践经验加 以总结和描述，并用语言表达出来，得到定性的、不精确的控制规则，不需要 被控对象的数学模型。模糊控制易于被人们接受，构造容易，鲁棒性和适应性 好。本文分析了汽包水位对象的动态特性，介绍传统的控制方式。由于锅炉水 位控制系统的调节器输入端常加有三个输入量，极易引起水位控制偏差，本文 提出了两种消除水位偏差的方法： (1) 辅助信号自消方法 (2)辅助信号对消方法。根据三冲量水位调节系统

3、控制水位误差，设计采用了三冲量PID串级控制方式，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。根据锅炉控制现状，提出了参数自整定模糊控制规则，设计了二输入三输 出自适应模糊PID控制器对汽包水位进行控制，克服了传统控制方式的控制效果不精确和参数难以调整等缺点。利用MATLAB对传统PID控制系统和三冲量自适应模糊PID控制系统仿真，结果表明后者的自适应能力更强，抗干扰能力和鲁棒性更好，保证水位的稳定。关键词汽包水位；三冲量；串级系统；PID 控制；模糊控制A Design of Fuzzy Control System to TheDrum Level of BoilerAbstrac

4、tThe self-adaptability fuzzy PID control with three impulses for boiler water levelthe system for boiler water level is a typical complicated thermal technical system. Atpresent, the diversified style boilers have several lacks in china. Dueto equipmentsseparated, no good of manage and the causation

5、 of technical, due to above causation,it is difficult that the most boiler in good condition, and increasing the fuelsconsumeand depressing efficiency of the boiler.The problem of modeling and control is an attention focus of people. The boilerwater lever is importance index of industry boiler safet

6、y and stabilization. It isimportance meaning to ensure water level in definite range for increasing quality ofsteam and reducing wastage of equipment and insuring safety of whole heart-power-net. At present, the mostly method is adopt the routine PID control. Because of routinePID control parameter

7、is changeless. It is difficulty to adapt the diversion disturbs andvariation objects. The method is not satisfy require and ideality.The fuzzy control based on foundation of manpower experience, it is summarizeand describe of skill workers practice experience, and it is giver expression to usingvoca

8、bulary, its gained mathematics model of no precise object. The fuzzy control isfacility to be accepted and structure.This article analyses dynamic characteristic of water level object and introducestraditional control method. Because there are three inputs accede to adopter of waterlever control sys

9、tem of boiler, it is easy to bring error of water lever controlling. Thisarticle puts forward two methods to dispel error of water lever: (l) assistant signal self-disappear. (2) Assistant signals each other dispel. According to three impulse controlwater lever error, designing three impulse PID cas

10、cade is control system.According to actuality of boiler control, putting forward fuzzy control rule ofparameter self-adaptability, designing The Self-Adaptability Fuzz PID Control System.This system gets over disadvantage of no precision and defaulting to adjust parameterfor using tradition control

11、methods. This article designs cascade PID control systemand self-adaptability fuzzy PID three impulse control system for controlling waterlevel. The simulation results show that fuzzy controller is better than the traditionalPID controller in MATLAB at adaptability, anti-jamming, etc.KeywordsWater l

12、evel；Three impulse；Cascade system；PID controller；Fuzzycontroller目录摘要.I.AbstractII第 1 章 绪论.1.1.1 锅炉汽包水位.1.1.2 锅炉汽包水位的系统结构.2.1.3 汽包水位调节对象的特性.3.1.3.1 汽包水位在给水流量作用下的动态特性.4.1.3.2 汽包水位在蒸汽流量扰动下的动态特性.6.1.4 本文研究目标.8.第 2 章 锅炉水位 PID 控制系统设计.9.2.1 PID 控制原理.9.2.2 PID 对控制的影响.1.0.2.2.1 比例 P 调节.1.0.2.2.2 积分 I 调节.1.0.2.2.3 微分 D 调节.