摘   要


隨著社會經(jīng)濟的高速發(fā)展，人們對生活供水的質(zhì)量和供水系統(tǒng)的可靠性的要求越來越高；再加上目前能源的緊缺，利用先進的自動化技術(shù)、控制技術(shù)以及通訊技術(shù)，設(shè)計出高性能、高節(jié)能、能適應(yīng)不同領(lǐng)域的恒壓供水系統(tǒng)以成為必然。本論文針對自來水廠的供水要求，設(shè)計了一套由PLC、變頻器、壓力變送器、多臺水泵機組、計算機等主要設(shè)備構(gòu)成的基于PLC變頻調(diào)速的恒壓供水系統(tǒng)。系統(tǒng)有效地解決了傳統(tǒng)供水方式的不足，并且增加了許多輔助功能，尤其提高了系統(tǒng)的可靠性。

本文分析了變頻調(diào)速恒壓供水系統(tǒng)的原理，特點，及相對于傳統(tǒng)恒壓供水方式的優(yōu)勢。系統(tǒng)利用壓力變送器將出水管網(wǎng)測得的水壓反饋給PLC，PLC經(jīng)過運算將模擬信號送給變頻器，變頻器在調(diào)節(jié)水泵轉(zhuǎn)速，這樣形成一個閉環(huán)控制系統(tǒng)，根據(jù)用水量的變化，隨時調(diào)節(jié)水泵運行速率且能循環(huán)切換水泵機組。實現(xiàn)有效節(jié)能的恒壓供水。

在水泵由變頻轉(zhuǎn)工頻運行方面，做了詳細的闡述，設(shè)計出了循環(huán)切換的控制電路和基于西門子s7-200PLC的控制程序。并利用s7-200的仿真軟件進行了水泵循環(huán)切換，變頻轉(zhuǎn)工頻的仿真運行。

關(guān)鍵詞： PLC；變頻調(diào)速；循環(huán)切換；恒壓供水；


 


 


 




Abstract


With the rapid development of social economy, the people's life quality and water supply system reliability and taller to the requirement of; Plus the current energy shortage of, use advanced automation technology, control technology and communication technology, the design of high performance, high energy saving, can adapt to different areas of constant pressure water supply system to become inevitable. This thesis aims to the requirements of the water supply of water works, designed a set of by PLC, frequency converter, pressure transmitter, many sets of pump unit, computers and other main components based on PLC, frequency conversion of the constant pressure water supply system. System effectively solved the deficiency of traditional water supply mode, and increased many auxiliary function, especially improve the reliability of system.

This paper analyzes the frequency control principle of constant pressure water supply system, characteristics, and compared with the traditional way of constant pressure water supply advantage. System using pressure transmitter will be measured water pipe pressure feedback to PLC, PLC after operation simulation signal to frequency converter, inverter in adjusting speed, this pump form a closed-loop control system according to the change of water pump operation, adjust rate and can cycle switching pump unit. To realize efficient energy-saving of constant pressure water supply.

The water pump power frequency by frequency conversion turn on running, this paper expounds in detail the circular switch, the design gives the control circuit and based on Siemens s7-200 PLC control procedures. And using the simulation software s7-200 the pump circulation switch, the simulation of power frequency inverter turn operation.


Keywords：PLC，F(xiàn)requency conversion，Circulation switch，Constant pressure water supply


 


目    錄

第一章 緒論 1

1.1背景介紹 1

1.2變頻恒壓供水特點 2

第二章 系統(tǒng)理論分析及控制方案的確定 3

2.1 供水系統(tǒng)要求 3

2.2變頻恒壓供水系統(tǒng)原理 3

2.3變頻恒壓供水系統(tǒng)控制方案的確定 4

2.3.1 供水系統(tǒng)的控制流程 4

2.3.2 總體設(shè)計 7

第三章 系統(tǒng)的硬件設(shè)計 8

3.1系統(tǒng)主要配置 8

3.1.1 可編程序控制器簡介 8

3.1.2 變頻器簡介 10

3.2 系統(tǒng)配置選型 14

3.2.1 PLC的選型 14

3.2.2 變頻器的選擇 16

3.2.3 水泵機組的選型 17

3.2.4 壓力變送器的選擇 18

3.3 系統(tǒng)主電路設(shè)計 18

3.4 系統(tǒng)控制電路設(shè)計 19

3.5 PLC的I/O地址分配 20

3.6 變頻器的參數(shù)設(shè)置 21

第四章 軟件設(shè)計 23

4.1主程序流程圖分析設(shè)計 23

4.1.1 系統(tǒng)供水流程 23

4.1.2 系統(tǒng)流程圖 24

4.1.3 供水泵切換分析 25

4.1.4 循環(huán)切換實現(xiàn) 25

4.2 系統(tǒng)控制程序設(shè)計 27

4.3 PID控制及其控制算法 37

第五章 系統(tǒng)仿真 41

結(jié)  論 47

參考文獻 48

謝  辭 49