摘要：温度是各种工业生产和科学实验中最普遍、最重要的热工参数之一。温度控制的精度对产品和实验结果将产生重大的影响。温度控制模式多样，PLC可靠性高，抗干扰能力强，易学易用，采用PLC控制是其中一种比较优越的控制方式。本文介绍了基于S7-200的炉温控制系统的设计方案。硬件方面采用了CPU型号为224的S7-200、PT100热电阻和温度模块EM235。软件方面以用指令向导生成的PID控制程序为主，在此基础之上根据指令向导生成的PID控制程序调节好的参数进而用编程法实现与用指令向导生成的PID控制程序。系统测试表明，本系统基本满足温度控制的要求，稳态性能良好，误差范围在1度之内。温度高于设定值与低于设定值的动态性能也基本满足要求，10度的偏差调节时间在20分钟之内。52932

毕业论文关键词：温度控制，PLC，PID

Abstract:Temperature is a variety of industrial production and scientific experiments are the most common, the most important one of the thermal parameters. The accuracy of temperature control will have a major impact on the product andthe experimental results. The temperature control mode of PLC persity, high reliability, strong anti-interference ability, easy to use, the PLC control is one of the comparative advantages of the control mode.This paper introduces the design scheme of control system of temperaturebased on S7-200. The hardware uses the CPU model for EM235 S7-200,PT100 thermal resistance and temperature module 224. Software using PID control program instructions generated by the wizard, on the basis of the above parameters according to the instruction wizard to generate the PIDcontrol program is adjusted and then programming method and instructionwizard to generate the PID control program.System test shows that, this system can basically meet the demand for temperature control, stable performance, error range is within 1 degrees. The temperature is higher than the set value is lower than the set value of thedynamic performance and can meet the basic requirements, a deviation of 10to adjust the time in 20 minutes.

key words：temperature control,plc,pid

 目    录 

1  绪论 5

1.1  课题研究背景及温度控制系统的发展 5

1.2  论文研究内容 5

2  PLC概述 6

2.1  PLC的产生 6

2.2  PLC的基本组成 6

3  软硬件配置 8

3.1  方案确定 8

3.2  硬件配置与选择 8

3.3  STEP 7 MICRO/WIN32软件介绍 9

3.4  安装STEP 7-MWIN32 V4.0 9

4  电气原理设计 10

5  程序设计 12

5.1  方案设计思路 12

5.2  PID控制程序设计 12

5.3  程序流程图 15

5.4  梯形图 15

6  系统测试 23

6.1  系统PID参数调节 23

6.2  系统稳态测试 23

6.3  系统升温动态性能测试 26

6.4  系统降温动态性能测试 28