毕业设计（论文）-电炉温度控制系统的PLC设计.doc

电炉温度控制系统的PLC设计  摘 要 温度是工业生产对象中主要的被控参数之一，本文通过设计温度控制系统， 体现PLC在模拟量信号检测与控制中应用的优越性。本文中被控对象是电炉，在 炉温自动控制系统中，炉温经过热电偶检测和温度变送器的转换，变为相应的电 压信号，送往PLC控制器，再经过模拟量输入/输出模块（A/D）转换为数字量， 并由程序将给定的温度值与测量值比较，然后根据偏差大小按比例调节规律，计 算出校正量。通过模拟量输入/输出模块的输出控制作用，消除炉温的偏差，从 而使炉温达到并稳定在给定的数值上。 关键词 PLC，温度控制，比例调节  ABSTRACT The temperature is a primarily being controlled parameter in the object of the industry production ,this text is an example of the temperature monitors and control system , and explains the PLC applied problem in imitate deal signal to monitor with the control . The electricity heat furnace is controlled object in this text ,in the automatic control system of the heat furnace temperature ,the temperature is examined by thermocouple and transformed by the thermostat , changed into the relevant electric voltage signal ,send to PLC controller ,and being transformed into arithmetic figure deal by imitate deal signal input/output the mold piece(A/D) ,given temperature will be compared to measured value from procedure , then according to the deviation size and inverse proportion regulates regulation ,and compute out to correct the deal .According to output control function of imitate deal signal input/output the mold piece ,eliminating warp of the heat furnace temperature ,accordingly the heat furnace temperature make attain stable and at the deviation size. Key Words PLC, Temperature control, Proportion adjust  目 录 摘 要 I ABSTRACT II 1 绪 论 1 1.1 课题背景、目的及意义 1 1.1.1 课题背景 1 1.1.2 课题的目的及意义 1 1.2 本文内容介绍 1 2 可编程控制器（PLC）概况 3 2.1可编程控制器的概述 3 2.2 PLC的定义 3 2.3 PLC的特点 3 2.4 PLC的发展 4 2.5 PLC的基本组成及各部分作用 4 2.5.1中央处理单元(CPU) 4 2.5.2存储器 5 2.5.3 I/0单元 6 2.5.4电源部分 6 2.5.5扩展接口 6 2.5.6通信接口 6 2