基于PLC变频调速恒压供水控制系统的设计

洛阳理工学院毕业设计（论文）I基于plc恒压供水变频控制系统设计摘要随着社会经济的迅速发展，人们对供水质量和供水系统可靠性的要求不断提高。再加上目前能源紧缺，利用先进的自动化技术、控制技术以及通讯技术，设计高性能、高节能、能适应不同领域的恒压供水系统成为必然趋势。本论文依据供水要求，设计了一套由PLC、变频器、远传压力表、多台水泵机组等主要设备构成的全自动变频恒压供水，具有全自动变频恒压运行、自动工频运行和现场手动控制等功能。系统有效地解决了传统供水方式中存在的问题，并具有多种辅助功能，增强了系统的可靠性。论文分析了多泵供水方式的各种供水状态及转换条件，分析了电机由变频转工频运行方式的切换过程及存在的问题。给出了实现有效状态循环转换控制的电气设计方案和PLC控制程序设计方案。论文还提出了一些增强系统运行可靠性的措施。关键词：可编程序控制器,变压变频调速,恒压供水,PLC洛阳理工学院毕业设计（论文）IIPLC-BASEDINVERTERCONTRLCONSTANTPRESSUREWATERSUPPLYSYSTEMDESIGNABSTRACTWiththerapidsocio-economicdevelopmentofwaterqualityandwatersupplysystemstoimprovereliabilityrequirements.Inaddition,thecurrentenergyshortage,theuseofadvancedautomationtechnology,controltechnologyandcommunicationtechnology,thedesignofhighperformance,highenergy,abletoadapttodifferentareasofconstantpressurewatersupplysystemhasbecomeaninevitabletrend.Inthispaper,basedonwaterrequirements,thedesignofasetbythePLC,frequencyconverter,FarEasTonepressure,multi-pumpunitconsistingofmajorequipmentsuchasautomaticfrequencyconversionconstantpressurewatersupply,withautomaticconstantfrequencyoperation,automaticfrequencyrunandon-sitefeaturessuchasmanualcontrol.Systemtoeffectivelysolvethetraditionalwayofwatersupplyproblems,andhaveavarietyofauxiliaryfunctions,andenhancethereliabilityofthesystem.Paperanalyzesthevariouswayswaterpumpthestatewatersupplyandconversionconditions,analysisofthemotortochangejobsbythefrequencyoftheswitchingfrequencyoperationandproblemsoftheprocess.GiventhestateofthecycletoachieveaneffectivechangeofcontroloftheelectricaldesignandPLCcontrolprogramdesign.Alsomadeanumberofpaperstoenhancesystemreliabilitymeasures.KEYWORDS:programmablelogiccontroller,VVVFspeedcontrol,constantpressurewatersupply,PLC洛阳理工学院毕业设计（论文）III目录前言.............................................................................................................1第1章恒压供水原理及工艺....................................................................21.1任务.....................................................................................................21.2工艺要求.............................................................................................21.3系统的组成和基本工作原理.............................................................2第2章PLC概述......................................................................................32.1PLC组成..............................................................................................32.1.1LC的输入.........................................................................................32.1.2PLC的输出...................................................................................32.1.3PLC的控制机制...........................................................................32.1.4PLC的定义...................................................................................52.1.5PLC的特点...................................................................................52.1.6PLC的性能指标...........................................................................62.1.7PLC的分类...................................................................................72.2PLC工作原理..................................................................................72.2.1循环扫描.......................................................................................72.2.2I/O响应时间.................................................................................82.2.3PLC中的存储器...........................................................................9第3章系统硬件设计..............................................................................103.1恒压供水系统的基本构成...............................................................113.2系统控制要求...................................................................................133.3控制系统的I/O点及地址分配........................................................143.4系统选型...........................................................................................173.5PLC模拟量控制单元的配置以及应用.........................................173.5.1EM235模拟量工作单元性能指标.............................................183.5.2校准及配置.................................................................................18洛阳理工学院毕业设计（论文）IV3.5.3EM235的安装使用.....................................................................183.5.4EM235工作程序编制.................................................................183.5.5电气控制系统原理图.................................................................20第4章系统程序设计..............................................................................234.1由“恒压”要求出发的工作泵组数量控制管理...............................234.2泵组泵站泵组管理规范...................................................................234.3程序的结果以及程序功能的实现...................................................23结论...........................................................................................................33致谢.............................................................................................................34参考文献.....................................................................................................35外文资料翻译.........................