编号淮安信息职业技术学院毕业论文题目基于PLC的变频恒压供水系统设计学生姓名仝猛学号42012107系部电气工程系专业机电一体化班级420121指导教师王玲顾问教师马砚芳摘要二〇一四年11月II摘要摘要随着我国经济的快速发展，城镇化的快速推进，人们生活水平的快速提高，小区的建设越来越迅速，因此对小区基础设施提出更高要求，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。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。本系统通过在西门子PLC变频器实训室进行系统的装调，验证了功能的正确性和完整性。关键词：小区供水PLC变频调速恒压供水IAbstractAbstractWiththerapiddevelopmentofoureconomy,therapiddevelopmentofurbanization,therapidincreaseofpeoplelivingstandard,residentialconstructionmoreandmorequickly,thusputforwardthehigherrequirementsforsmallinfrastructure,accordingtotheChinesecitywatersupplyrequirements,designasetofvariablefrequencyspeedconstantpressurewatersupplysystembasedonPLC.Thesystemconsistsofthreepumpmotor,whichcomprisesafrequencyconversioncycleoperationmode.Therealizationofthree-phasemotorpumpsoftstartandfrequencyconversionspeedadjustmentbyfrequencyconverter,operationswitchadoptsthe"startstopfirst"principle.ThepressuresensordetectsthecurrenthydraulicpressuresignalissenttothePLC,comparedwiththesetvalue,PIDoperation,soastocontrolthetransducersoutputvoltageandfrequency,andthenchangethewaterpumpmotorspeedtochangethewatersupplypipenetworkpressure,finallykeepstablearoundthesettingvalue.Keywords:DistrictwatersupplyPLCvariablefrequencyspeed-regulationconstant-pressurewaterII目录目录摘要................................................................................................................................IABSTRACT..................................................................................................................II第一章绪论....................................................................................................................11.1传统供水系统........................................................................................................11.2基于PLC的变频恒压供水系统...........................................................................1第二章可编程逻辑控制器简介....................................................................................22.1可编程逻辑控制器（PLC）的定义....................................................................22.2PLC的组成...........................................................................................................22.3PLC的工作原理...................................................................................................32.4西门子PLC(S7-200)的简介................................................................................4第三章变频器在恒压供水系统中的应用...................................................................53.1变频恒压供水的系统组成及特点........................................................................53.1.1系统组成.........................................................................................................53.1.2系统的特点...............................................................................
