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基于串级控制的锅炉温度史密斯预估器的改进

时间:2017-04-18 19:05来源:毕业论文
论文设计采用串级控制和史密斯预估控制相结合的方式来改善锅炉温度系统。最后用Matlab对控制方案进行仿真,并与普通控制方法进行对比,来观察性能改善成果

摘要:现代工业生产过程中,不少工业对象存在着纯滞后时间。这种纯滞后时间或者是由于物料或能量传输过程中所引起的。或者是由于对象中多容积所引起的,或者是高阶对象低阶近似后所形成的等效滞后。由于锅炉温度系统也存在较大时滞,本文研究基于串级控制的史密斯预估控制来改善控制性能。串级控制系统是两只调节器串联起来工作,其中一个调节器的输出作为另一个调节器的给定值的系统,适用于时间常数及纯滞后较大的对象,如加热炉、蒸馏塔、锅炉减温水的汽温控制。由于副回路等效被控对象的时间常数比副对象的时间常数小很多,因而由于副回路的引入而使对象的动态特性有了很大的改善,串级控制有利于提高系统克服干扰的能力。史密斯预估器是史密斯(O.J.M Smith)在1957年提出了一种预估补偿控制方案,可以抵消纯滞后特性所造成的影响,减小超调量和加速调节过程,提高控制质量。本次论文设计采用串级控制和史密斯预估控制相结合的方式来改善锅炉温度系统。最后用Matlab对控制方案进行仿真,并与普通控制方法进行对比,来观察性能改善成果。7333
关键词:锅炉温度系统;史密斯预估器;纯滞后
Improvement of boiler temperature Smith cascade control based on the predictor
Abstract:In Modern industrial production process, many industrial objects exist pure lag time. This lag time or is caused by material or energy transfer process. Or is caused by objects in volume, or the equivalent of higher order objects formed by low order approximation of the lag. Because the boiler temperature system also exist large time-delay is studied in this paper, the cascade control Smith predictive control based on to improve the control performance. The cascade control system are two regulator connected in series, wherein a regulator output as another regulator setpoint, suitable for time constant and chaotic lag larger objects, such as steam temperature of boiler furnace, distillation tower, attemperating water control. The equivalent circuit of controlled object is much smaller time constant than the time constant Deputy objects, and due to the introduction of secondary circuit and the dynamic characteristics of the object has been greatly improved, cascade control is conducive to improve the system to overcome the interference. Smith predictor is Smith (O.J.M Smith) proposed in 1957 a predictive compensation control scheme, can offset the impact of time delay caused by decreasing the overshoot, and accelerate the adjustment process, improve quality control. The design of the cascade control and Smith predictive control combination to improve the boiler temperature system. Finally, the control scheme is simulated with Matlab, and compared with conventional control methods, to observe the performance improvement.
Keywords:The temperature in the boiler system;Smith predictive control;Pure lag
目录
1  绪论
1.1  课题背景和意义    1
1.1.1  国内外温度控制研究现状及发展趋势    1
1.1.2  史密斯(Smith)控制概要    1
1.1.3  锅炉燃烧控制系统概要    2
1.2  课题研究内容    2
2  锅炉温度系统    3
2.1  锅炉温度控制的现状    4
2.2  锅炉温度控制的原理    4
2.3  锅炉温度串级控制系统    5
3  PID控制概要    8
3.1  PID控制介绍    8
3.2  基于PID的锅炉温度控制系统设计    10
4  基于串级控制的锅炉系统    12
4.1  系统简述    12
4.2  控制方式的确定    12 基于串级控制的锅炉温度史密斯预估器的改进:http://www.751com.cn/zidonghua/lunwen_5237.html
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