(此文档为word格式,下载后您可任意编辑修改!)
毕 业 设 计(论 文)
设计(组态)
(英文): Design of Feedforward and Feedback
题目:基于S7-300锅炉内胆水温的前馈-反馈控制系
Control Systems Based on S7-300 Boiler Water Temperature (Configuration)
院 别: 自动化学院 专 业: 自动化 姓 名: 肖 奎 指导教师: 李 虎 山 日 期: 2014年4月
0
基于S7-300锅炉内胆水温的前馈-反馈控制系
统设计(组态)
摘要
温度是常见的过程参数之一,许多的生产过程都离不开对温度的控制,温度的控制往往是对加热和冷却的平衡,锅炉正是这样的系统,当加热大于冷却时整个系统升温;反之则降温;二者若是趋于相等就可以使温度趋于稳定。若是采用单纯的反馈控制对锅炉内胆水温进行控制,由于流量变化快而温度控制滞后大就会导致系统的稳定性、快速性较差,不能取得理想的控制效果。解决这个问题的办法就是加入对主要扰动流量的前馈补偿环节构成锅炉内胆水温的前馈-反馈控制系统,使得流量的变化能够迅速得到补偿,提高系统的响应速度。
近年来,可编程控制器(PLC)依托着可靠性高,抗干扰,功能强大等特点得到了广泛的运用,随着生产和编程的技术不断进步,越来越多的控制方式得以在PLC上实现。本设计将围绕西门子S7-300 PLC从前馈-反馈控制系统的介绍、PLC及测量变送仪表设备的选择、软件的展示及组态编程这三个方面来阐述锅炉内胆水温的前馈-反馈控制系统的设计,力求展示出前馈-反馈控制系统的特点。通过本设计可以观测到前馈-反馈控制系统在以流量变化为主要扰动的情况下对锅炉内胆的水温可以取得较好的控制效果。
关键词:前馈-反馈控制; PLC;温度
Design of Feedforward and Feedback Control
Systems Based on S7-300 Boiler Water
Temperature (Configuration)
ABSTRACT
Temperature is one of the common process parameters , many production processes are inseparable from the temperature control , temperature control is often the balance of the the cooling of the entire system ; otherwise cool ; both tend to be equal if you can make the temperature to stabilize. If using a simple feedback control to control the temperature of the boiler tank ,due to rapid changes in flow and temperature control will lead to a large not achieve the desired control effect. To solve this problem is to add a feedforward flow of former major disturbance feedforward compensation constitutes a part of the interior temperature of the boiler - a feedback control system, making changes in flow can be compensated quickly , improve the response speed of the system.
In recent years , programmable logic controller (PLC) relying on widely used , with production and programming technology advances , more and more control to the PLC achieved. This design will focus on Siemens S7-300 PLC feedforward - feedback control system introduction, select PLC transmission instruments and measuring equipment , software, display and programming of these three aspects to elaborate boiler water tank feedforward - feedback control system design , and strive to demonstrate feedforward - feedback control system characteristics. This design can be seen through the feedforward - feedback control system to flow in the case of major disturbances in the water tank of the boiler can achieve better control effect.
Keywords: Feedforward and feedback control; PLC;Temperature
2
目录
1 绪论 .................................................................. 1 2 基本背景知识 .......................................................... 2
2.1 前馈-反馈控制 .................................................... 2
2.1.1 前馈控制系统 ................................................ 2 2.1.2 前馈-反馈控制系统 ........................................... 3 2.2 设计任务分析 ..................................................... 4 3 控制系统硬件 .......................................................... 6
3.1 控制设备 ......................................................... 6
3.1.1 PLC基本介绍................................................. 6 3.1.2 S7-300 PLC CPU模块说明 ...................................... 7 3.1.3 S7-300 PLC信号模块(SM)说明 ................................ 7 3.2 测量变送设备 ..................................................... 8
3.2.1 温度传感器、变送器 .......................................... 8 3.2.2 流量计 ...................................................... 9
4 系统的设计过程 ........................................ 错误!未定义书签。
4.1 系统装置接线 ..................................... 错误!未定义书签。 4.2 模拟量信号采集 ................................... 错误!未定义书签。 4.3 西门子Step 7编程软件的简介 ...................... 错误!未定义书签。 4.4 PLC程序的编写 ................................... 错误!未定义书签。 5 组态的建立过程 ........................................ 错误!未定义书签。
5.1 组态软件介绍 .................................... 错误!未定义书签。 5.2 组态的建立过程 ................................................. 10 5.3 控制参数的整定 ................................................. 11 结语 ................................................................... 14 参考文献 ............................................................... 32 致谢 ................................................................... 33