基于plc控制的變頻調(diào)速恒壓供水系統(tǒng)畢業(yè)論文

摘  要
隨社會(huì)經(jīng)濟(jì)的迅速發(fā)展，人們對(duì)供水質(zhì)量和供水系統(tǒng)可靠性的要求不斷提高；再加上目前能源緊缺，利用先進(jìn)的自動(dòng)化技術(shù)、控制技術(shù)以及通訊技術(shù)，設(shè)計(jì)高性能、高節(jié)能、能適應(yīng)不同領(lǐng)域的恒壓供水系統(tǒng)成為必然趨勢(shì)。
本設(shè)計(jì)是針對(duì)居民生活用水而設(shè)計(jì)的。由變頻器、PLC、PID調(diào)節(jié)器和組成控制系統(tǒng)，調(diào)節(jié)水泵的輸出流量。電動(dòng)機(jī)泵組由三臺(tái)水泵并聯(lián)而成，由變頻器或工頻電網(wǎng)供電，根據(jù)供水系統(tǒng)出口水壓和流量來控制變頻器電動(dòng)機(jī)泵組的速度和切換，使系統(tǒng)運(yùn)行在最合理狀態(tài)，保證按需供水。
     本文介紹了采用PLC控制的變頻調(diào)速供水系統(tǒng)，由PLC進(jìn)行邏輯控制，由變頻器進(jìn)行壓力凋節(jié)。在經(jīng)過PID運(yùn)算，通過PLC控制變頻與工頻切換，實(shí)現(xiàn)閉環(huán)自動(dòng)調(diào)節(jié)恒壓變量供水。運(yùn)行結(jié)果表明，該系統(tǒng)具有壓力穩(wěn)定，結(jié)構(gòu)簡(jiǎn)單，工作可靠等特點(diǎn)。

關(guān)鍵詞：變頻調(diào)速 ；恒壓供水；PID調(diào)節(jié)；PLC 
 
ABSTRACT
With the rapid development of social economy； it demands the better of water supply' s quality and reliability of water supply system. Meanwhile energy resources are seriously lack. So it is inevitable tendency to design water supply system which has high function and saves on energy well， with help of advanced technique of automation， control and communication. At the same time this system can adapt different water supply fields.
It is very important of the Water Supply System in Constant Pressure for the water supply in industrial and citizen existence. It is consist of the variable frequency and speed regulation， PLC， PID control system for the control system. It controls the outcome of the pumps. The generator pumps are consist of parallel three pumps， and the power come from variable frequency and speed regulation or power grid. According to the water supply of constant pressure’s outcome water press and flux， the control system control the variable frequency and speed regulation， parallel pumps’ speed and cut over， cause the system move in the best rational situation， assure according to wants supply water. This design has many merits such as save energy.
In this paper，the control principle of VVVF providing-water system is introduced，we use PLC to carry on logic control and use inverter to modulate pressure．Through PID control principle .we realize Closed-loop control in VVVF Providing-water System．The result indicates that the system has the stable pressure，simple structure，and reliable work．

Keywords： variable frequency and speed regulation；water supply of constant pressure；PID control system；PLC

 
 
目錄

摘  要 1
ABSTRACT 2
1 緒論 1
1.1變頻恒壓供水產(chǎn)生的背景和意義 1
1.2變頻恒壓供水系統(tǒng)的國(guó)內(nèi)研究現(xiàn)狀 3
1.3課題來源及本文的主要研究?jī)?nèi)容 5
1.4本論文中所做的工作 5
2 恒壓供水系統(tǒng)的基本構(gòu)成 6
3 變頻器和壓力傳感器 8
3.1 變頻器的基本結(jié)構(gòu) 8
3.2 變頻器的分類及工作原理 11
3.3 變頻器的操作方式及使用 12
3.4 變頻器硬件選擇 13
3.5 壓力傳感器 14
4 PLC選擇及應(yīng)用 16
4.1 PLC在恒壓供水泵站中的主要任務(wù) 16
4.2 PLC模擬量擴(kuò)展單元的配置及應(yīng)用 16
4.2.1 模擬量輸入模塊的功能及與PLC系統(tǒng)的連接………………………….17
4.2.2 模擬量輸入模塊緩沖存儲(chǔ)器（BFM）的分配 18
4.2.3  模擬量輸出模塊的功能及PLC系統(tǒng)連接 20
4.2.4 模擬量輸出模塊的偏置、增益及分配 21
5  PID控制器的設(shè)計(jì) 22
5.1 PID控制算法及特點(diǎn) 23
5.2 PID參數(shù)整定的相關(guān)原則 25
5.3 PID指令的使用注意事項(xiàng) 26
5.4 PID回路類型的選擇 26
5.5 正作用或反作用回路 27
6 系統(tǒng)的設(shè)計(jì) 28
6.1 系統(tǒng)要求 28
6.2控制系統(tǒng)的I/O及地址分配 28
6.3 PLC系統(tǒng)選型 30
6.4 電氣控制系統(tǒng)原理圖 30
6.4.1主電路圖 30
6.4.2 控制電路圖 32
6.5 系統(tǒng)程序設(shè)計(jì) 33
6.5.1由“恒壓”要求出發(fā)的工作泵組數(shù)量管理 34
6.5.2  多泵組泵站泵組管理規(guī)范 34
6.5.3系統(tǒng)流程圖設(shè)計(jì) 34
6.5.4程序的結(jié)構(gòu)及程序功能的實(shí)現(xiàn) 36
6.5.5系統(tǒng)的運(yùn)行分析 38
致謝 39