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。本课题用PLC实现了自动供水控制系统，介绍了恒压供水的基本原理以及系统构成的基础，说明了可编程控制器（PLC）在恒压供水系统中所担任的角色。从系统的整体设计方案和实际需求分析开始，紧密的联系实际生活的需要，力求做到使系统运行稳定，操作简便，解决实际中问题，保证供水安全、快捷、可靠。关键字：PLC恒压供水变频器ABSTRACTWiththerapiddevelopmentofsocialeconomy,itisdemandedthebetterofwatersupply’squalityandreliabilityofwatersupplysystem.Meanwhileenergyresourcesareseriouslylack.Soitisinevitabletendencytodesignwatersupplysystemwhichhashighfunctionandsavesonenergywell,withhelpofadvancedtechniqueofautomation,controlandcommunication.Atthesametimethissystemcanadaptdifferentwatersupplyfields.ThissubjectrealizetheautomaticwatercontrolsystemthatusedofPLC,itintroducedthebasicprinciplethatconstantvoltagesupplieswaterandfoundationthatthesystemform,havestatedtheroleservedasoftheprogrammablecontroller(PLC)inthewater-supplysystemofconstantvoltage.Sincethewholedesignplanofthesystemandactualdemandareanalysed,theneedofcloselifeofintergratingwithpractice,makeeveryefforttomakesuretomakethesystemrunsteadily,easyandsimpletohandle,solveandhittheproblemactually,guaranteetosupplywaterofthesecurity,swift,reliable.Constantvoltagehassuppliedwaterandguaranteedtosupportthewaterqualityamount,thecontrolsystemtakingPLCashostcomputerhasenrichedthesystematiccontrolfunction,haveimprovedsystematicdependability.Keyword:PLC(programmablecontroller),Constantvoltage,supplieswater,Frequencyconverter目录第一章绪论................................................................................................................11.1变频恒压供水产生的背景和意义.......................................................................11.2变频恒压供水系统的国内研究现状...................................................................11.3本文研究的系统组成和工作原理.......................................................................2第二章PLC概述.......................................................................................................32.1PLC介绍..............................................................................................................32.2PLC工作原理......................................................................................................42.3PLC的编程语言..................................................................................................62.4PLC的分类..........................................................................................................92.5PLC控制系统的结构........................................................................................10第三章系统硬件的设计..........................................................................................133.1恒压供水系统的基本构成................................................................................153.2系统控制要求....................................................................................................173.3控制系统的I/O点及地址分配.........................................................................183.4系统选型.....................................................................................
