于基plc的变频调速恒压供水系统-学位论文.doc

摘要基于PLC的变频调速恒压供水系统毕业设计论文摘要本论文根据中国城市小区的供水要求，设计了一套基于PLC的变频调速恒压供水系统,并利用组态软件开发良好的运行管理界面。变频恒压供水系统由可编程控制器、变频器、水泵机组、压力传感器、工控机等构成。本系统包含三台水泵电机，它们组成变频循环运行方式。采用变频器实现对三相水泵电机的软启动和变频调速，运行切换采用“先启先停”的原则。压力传感器检测当前水压信号，送入PLC与设定值比较后进行PID运算，从而控制变频器的输出电压和频率，进而改变水泵电机的转速来改变供水量，最终保持管网压力稳定在设定值附近。通过工控机与PLC的连接，采用组态软件完成系统监控，实现了运行状态动态显示及数据、报警的查询。关键词：变频调速，恒压供水，PLC，组态软件ABSTRACTABSTRACTAccordingtotherequirementofChina'surbanwatersupply,thispaperdesignsasetofwatersupplysystemoffrequeceycontrolofconstantvoltagebasedonPLC,andhavedevelopedgoodoperationmanagementinterfaceusingSupervisionControlandDataAcquisition.ThesystemismadeupofPLC,transducer,unitsofpumps,pressuresensorandcontrolmachineandsoon.Thissystemisformedbythreepumpgenerators,andtheyformthecirculatingrunmodeoffrequencyconversion.Withgeneralfrequencyconverterrealizeforthreephasepumpgeneratorsoftstartwithfrequencycontrol,operationswitchadoptstheprincipleof”startfirststopfirst”.Thedetectionsignalofpressuresensorofhydraulicpressure,viaPLCwithsetvaluebycarryoutPIDcomparisonoperation,so,controlfrequencyandtheexportvoltageoffrequencyconverter,andthentherotationalspeedthatchangespumpgeneratorcometochangewatersupplyquantity,eventually,itisnearbytomaintainpipenetpressuretostabilizewhensetvalue.ThroughworkcontrolmachinetheconnectionwithPLC,withgroupformsoftwareconsummatelysystematicmonitoring,haverealizedoperationstatedevelopmenttoshowanddata,reporttothepoliceinquiry.Keywords:variablefrequencyspeed-regulating,constant-pressurewatersupply,PLC,supervisioncontrolanddataacquisition.目录目录TOC\o"1-2"\h\z\uHYPERLINK\l"_Toc233100241"1绪论PAGEREF_Toc233100241\h1HYPERLINK\l"_Toc233100242"1.1课题的提出PAGEREF_Toc233100242\h1HYPERLINK\l"_Toc233100243"1.2变频恒压供水系统的国内外研究现状PAGEREF_Toc233100243\h3HYPERLINK\l"_Toc233100244"1.3PLC概述PAGEREF_Toc233100244\h5HYPERLINK\l"_Toc233100245"1.4本课题的主要研究内容PAGEREF_Toc233100245\h7HYPERLINK\l"_Toc233100246"2系统的理论分析及控制方案确定PAGEREF_Toc233100246\h8HYPERLINK\l"_Toc233100247"2.1变频恒压供水系统的理论分析PAGEREF_Toc233