基于PLC控制的加熱爐溫度控制系統(tǒng)設(shè)計

摘要

溫度控制系統(tǒng)廣泛應(yīng)用于工業(yè)控制領(lǐng)域，如鋼鐵廠、化工廠、火電廠等鍋爐的溫度控制系統(tǒng)，電焊機(jī)的溫度控制系統(tǒng)等。加熱爐溫度控制在許多領(lǐng)域中得到廣泛的應(yīng)用。這方面的應(yīng)用大多是基于單片機(jī)進(jìn)行PID 控制, 然而單片機(jī)控制的DDC 系統(tǒng)軟硬件設(shè)計較為復(fù)雜, 特別是涉及到邏輯控制方面更不是其長處, 然而PLC 在這方面卻是公認(rèn)的最佳選擇。加熱爐溫度是一個大慣性系統(tǒng)，一般采用PID調(diào)節(jié)進(jìn)行控制。隨著PLC功能的擴(kuò)充在許多PLC 控制器中都擴(kuò)充了PID 控制功能, 因此在邏輯控制與PID控制混合的應(yīng)用場所中采用PLC控制是較為合理的。本設(shè)計是利用西門子S7-300PLC控制加熱爐溫度的控制系統(tǒng)。首先介紹了溫度控制系統(tǒng)的工作原理和系統(tǒng)的組成，然后介紹了西門子S7-300PLC和系統(tǒng)硬件及軟件的具體設(shè)計過程。

關(guān)鍵詞：西門子S7-300PLC，PID，溫度傳感器，固態(tài)繼電器

 
The application of Siemens S7-300 in temperature control

Abstract
Temperature control system has been widely used in the industry controlled field，as the temperature control system of boilers and welding machines in steel works、chemical plant、heat-engine plant etc. Heating-stove temperature control has also been applied widely in all kinds of fields .The application of this aspect is based on SCM which is making the PID control, yet the hardware and software design of DDC system controlled by SCM is somewhat complicated , it’s not an advantage especially related to logic control, however it is accepted as the best choice when mentioned to PLC.
The furnace temperature of heating-stove is a large inertia system，so generally using PID adjusting to control. With the expanding of PLC function, the control function in many PLC controllers has been expanded. Therefore it is more reasonable to apply PLC controlling in the applicable fields where logical control and PID control blend together. The design has utilized the control system with which Siemens S7-300 PLC control the temperature heating-stove. In the first place this paper presents the working principles of the temperature control system and the elements of this system. Then it introduces Siemens S7-300 PLC and the specific design procedures of the hardware and the software.

Key words：Siemens S7-300 PLC，PID，temperature pickup, solid state relay

 
目錄
摘要 I
Abstract II
第一章  引言 1
1.1系統(tǒng)設(shè)計背景 1
1.2系統(tǒng)工作原理 1
1.3系統(tǒng)設(shè)計目標(biāo)及技術(shù)要求 2
1.4技術(shù)綜述 2
第二章 系統(tǒng)設(shè)計 4
2.1控制原理與數(shù)學(xué)模型 4
2.1.1PID控制原理 4
2.1.2掌握S7-300PLC的PID指令及應(yīng)用方法 8
2.1.3PID指令的使用注意事項 13
2.2采樣信號和控制量分析 14
2.3系統(tǒng)組成 15
第三章   硬件設(shè)計 16
3.1 PLC的基本概念 16
3.1.1模塊式PLC的基本結(jié)構(gòu) 16
3.1.2 PLC的特點 18
3.1.3PLC的應(yīng)用領(lǐng)域 19
3.2 PLC的工作原理 22
3.2.1邏輯運算 22
3.2.2 PLC的循環(huán)處理過程 23
3.2.3用戶程序的執(zhí)行過程 25
3.3 S7-300簡介 25
3.3.1數(shù)字量輸入模塊 26
3.3.2 數(shù)字量輸出模塊 26
3.3.3數(shù)字量輸入/輸出模塊 27
3.3.4模擬量輸入模塊 28
3.3.5模擬量輸出模塊 30
3.3.6 S7-300的其他模塊 31
3.4溫度傳感器 32
3.5固態(tài)繼電器 34
第四章 軟件設(shè)計 38
4.1STEP7編程軟件簡介 38
4.1.1STEP7概述 38
4.1.2STEP 7的硬件接口 38
4.1.3 STEP 7的編程功能 38
4.1.4 STEP 7的硬件組態(tài)與診斷功能 39
4.2 STEP7項目的創(chuàng)建 40
4.2.1使用向?qū)?chuàng)建項目 40
4.2.2直接創(chuàng)建項目 42
4.2.3硬件組態(tài)與參數(shù)設(shè)置 43
4.3用變量表調(diào)試程序 51
4.3.1系統(tǒng)調(diào)試的基本步驟 51
4.3.2 變量表的基本功能 52
4.3.3變量表的生成 53
4.3.4 變量表的使用 54
4.4 S7-300的編程語言 55
4.4.1PLC編程語言的國際標(biāo)準(zhǔn) 55
4.4.2STEP7中的編程技術(shù) 56
結(jié)束語 61
參考文獻(xiàn) 62
附錄 63
致謝 65