搜索
青岛理工大学毕业设计（论文）题目PLC控制的恒压供水系统设计学生姓名：林倍正指导教师：季鸿雁自动化工程学院电气工程专业07级4班年月日中文摘要进去21世纪以来，随着改革开放的不断发展深入，我国城市化建设的进一步推进及其经济迅猛发展，人民的物资生活水平不断提高；与此同时，城市城镇居民需水量不断增多，对城市供水系统提出了更高更严格的要求。能否实现供水的可靠性、稳定性、经济节能性关系到城区的建设和经济的发展，也直接影响到城区居民的正常生产、工作、学习、生活。针对目前的小区供水系统中存在的电能浪费、水资源浪费且供水质量差等一些列问题，本文研究并设计了一种变频调速恒压供水控制器。该控制器是以三菱FX2NPLC为主要器件，并与变频器、压力传感器等器件结合起来，共同构成了恒压供水系统。该系统是以管网水压为设定参数，根据本小区供水管网压力的实际需要和季节变化（如夏季为用水高峰期），可在一天中不同的时间段，设定不同的压力给定值，实现管网水压的自动调节，即实现恒压供水。论文论述了多种方案合理性，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。最终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。系统有效地解决了传统供水方式中存在的问题，增强了系统的可靠性。并与计算机实现了有机的结合，可通过PLC的上位计算机监控软件对压力设定值进行实时调整提升了系统的总体性能。关键词：PLC，变频，供水，恒压ABSTRCTInthe21stcentury,withthecontinuousdevelopmentofreformandopeningup,thedeepinurbanizationconstructiontofurtherpromoteandrapideconomicdevelopment,people'smateriallifelevelincreases;Meanwhile,thecityurbanresidentsofurbanwatersupply,increasingmorestrictsystemputforwardhigherrequirement.Realizationofwatersupplyreliabilityandstability,economicenergy-savingsextourbanconstructionandeconomicdevelopment,alsodirectlyaffectsthenormalproductionandurbanresidentswork,studyandlife.Aimingattheexistinginthevillagewatersupplysystemwasteofelectric,waterresourceswasteandpoorwaterquality,thispaperstudiessomeproblemanddesignedakindofvariablefrequencyspeedregulationconstantpressurewatersupplycontroller.ThiscontrollerisFX2NPLCforthemaindevicemitsubishiinverter,anddevicessuchaspressuresensoriscombinedtomakeaconstantpressurewatersupplysystem.Thissystemisforpipepressure,thisvillagesetparametersaccordingtotheactualneedsofwatersupplypipepressureandtheseasonalvariation(suchassummerpeak),butforwaterinonedayandsetvariousdifferenttimeperiods,realizethegivenvalueofpressurepipelinepressure,namely,realizeautomaticregulationofconstantpressurewatersupply.Thispaperdiscussesthevarioussolutionsrationality,analyzedallkindsofwatersupplytothewatersupplypumpwaystatusandconversionconditionbyfrequencyconversionmotor,analyzestheoperatingmodeturnpowerfrequencyswitchingandexistingproblems.EventuallygivesrealizeeffectiveelectricconversioncontrollingstatecycledesignschemeandPLCcontrolprogramdesign.Systemeffectivelysolvethetraditionalwayofexistingproblemsofwatersupply,andenhancethesystemreliability.Andwithcomputertorealizetheorganicunion,butthroughPLCPCmonitorsoftwarereal-timeadjustmentofpressuresettingtheoverallperformanceimprovedsystem.Keywords:PLC,frequencyconversion,watersupply,constantpressure目录目录..........................................................................................................................................................4第一章绪论............................................................................................................................................51.1研究背景及意义...............................................................................................................51．2变频恒压供水系统的国内外研究现状..........................................................................51．3可编程控制器(PLC)的特点............................................................................................51.4国内外变频调速技术的发展与现状................................................................................61.5本课题的主要研究内容....................................................................................................6第二章系统的控制原理及其方案论证................................................................................................72．1变频恒压供水系统理论分析..........................................................................................72．1．3变频恒压供水系统的近似数学模型................................................................82.1.4PID算法..................................................................................错误!未定义书签。2．2变频恒压供水系统控制方案的确定..............................................................................92．2．1供水系统的控制流程........................................................................................92．2．2系统运行方式的分析........................................................................................92．2．3系统的切换条件..............................................................................................10第三章系统的硬件工作原理及硬件选择..........................................................................................113．1系统主要配置的选型....................................................................................................113.1.1水泵机组的选型..................................................................................................113.1.2、压力变送器及数显仪的选型...........................................................................113.1.3变频器的选型与设定..........................................................................................113.1.4PLC的选型............................................................................................................133.2系统的硬件设计..............................................................................................................153．2．1主电路设计......................................................................................................153．2．2电气控制电路设计.......................