带三断保护的智能定位器的设计与实现

发布时间：2018-01-19 20:50

本文关键词： 阀门定位器三断保护智能控制 I/P转换器喷嘴挡板　出处：《复旦大学》2011年硕士论文　论文类型：学位论文

【摘要】：本文介绍了一种具有“断电、断信号、断气源”保护功能的智能二线制阀门定位器的实现,讨论了其工作原理、实现控制所需的硬件和软件结构设计及其智能定位器内部PID控制算法。调节阀是自动调节系统的重要组成部分,通常被用来调节流入(或流出)调节对象的物质或能量,以实现对生产过程中各种热工参数的自动控制。阀门定位器是气动调节阀实现有效控制的核心部件,由于受管路中阀板的前后压差、阀的机械性能等因素的影响,阀门的行程不能到达指令要求的位置,存在过调、偏差和回差等现象,定位器的核心作用是对应上述因素对调节阀的影响量,自动增加或减小输出到阀门的压缩空气量,纠正阀门行程产生的偏差,使其回复到控制信号与阀门行程的对应关系上,将外部的干扰、超调、滞后等不利影响减至最小提升被调对象的品质1]。研究阀门定位器,对提高阀门控制精度和响应速度,进而节约能源、成本,提高产能具有重要的意义。传统的定位器智能程度低、控制精度差、耗气量大、不能实现阀门的“断电、断信号、断气源”保护功能。随着电力、化工、造纸等行业的飞速发展,以及过程控制日益智能化的发展需求,智能阀门定位器的需求量与日俱增,作为智能执行元件,被广泛应用在各种自动化控制系统中。开发具有自主知识产权的新—代智能型阀门定位器已经势在必行[4]。经过对这个课题的分析与研究,结合公司的新产品开发项目,最终确定了以喷嘴挡板原理为基础,开发高度智能、并能实现三断保护功能的阀门定位器。设计定位器采用的原则是：提高定位器的智能水平,以提高其控制精度和稳定性,降低工艺控制波动,同时降低静态耗气量、兼顾产品可靠性。本课题设计的智能阀门定位器,除具备一般智能定位器的基本功能外,还兼具“三断保护,,的功能,可以在定位器断电、断信号、断气源的情况下,使得阀门保持在当前的位置。在定位器内部智能控制算法方面,本文介绍了采用的PID优化控制算法等关键技术和工艺。对各个模块的设计构想及具体实施方案,如何实现准确定位;如何实现阀门的三断保护；如何完成显示、工作方式的管理及系统自诊断等进行了详细探讨。到论文完成时,多批定位器已在多个客户现场试用,实际应用效果良好。
[Abstract]:This paper introduces the realization of an intelligent two-wire valve positioner with the protection function of "power off, cut off signal and gas stop source", and discusses its working principle. The design of hardware and software structure and the PID control algorithm of intelligent locator are introduced. The regulator is an important part of the automatic control system and is usually used to regulate the material or energy that flows in or out of the regulating object. In order to realize the automatic control of various thermal parameters in the production process, the valve positioner is the core part of the pneumatic control valve to realize effective control, because of the pressure difference between the front and back of the valve plate in the pipeline. Valve mechanical properties and other factors, valve stroke can not reach the required position, there are overadjustment, deviation and return error phenomenon, the central role of the locator is corresponding to the above factors on the control valve. Automatically increase or decrease the compressed air output to the valve, correct the deviation produced by the valve stroke, make it return to the corresponding relationship between the control signal and the valve stroke, and overshoot the external interference. The unfavorable effects such as lag are reduced to a minimum to improve the quality of the target being adjusted 1]. The study of valve positioner is of great significance to improve valve control accuracy and response speed, thus saving energy, cost and productivity. Traditional positioner has low intelligence, poor control precision and large gas consumption. The protection function of the valve can not be realized. Along with the rapid development of electric power, chemical industry, papermaking and so on, as well as the increasingly intelligent development demand of process control. The demand for intelligent valve positioner is increasing day by day. As an intelligent actuator, it is widely used in various automatic control systems. It is imperative to develop a new generation of intelligent valve positioner with independent intellectual property rights. [4]. Through the analysis and research of this subject, combined with the new product development project of the company, the development of high intelligence is determined based on the principle of nozzle baffle. And the valve positioner which can realize the function of three-break protection. The principle used in the design of the locator is to improve the intelligent level of the locator in order to improve its control accuracy and stability, reduce the fluctuation of process control, and reduce the static gas consumption at the same time. The intelligent valve positioner designed in this subject not only has the basic function of the general intelligent positioner, but also has the function of "three-off protection", which can be used in the locator to cut off the power and signal. Keep the valve in its current position when the gas supply is cut off. In the aspect of internal intelligent control algorithm of locator, this paper introduces the key technology and technology such as PID optimal control algorithm. How to realize the three-break protection of valve; How to complete the display, the management of the working mode and the system self-diagnosis are discussed in detail. By the time of the completion of the paper, the multi-batch locator has been tried in many customers and the practical application effect is good.
【学位授予单位】：复旦大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH134

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