基于PLC的空气压缩机变频调速控制系统

洛阳理工学院毕业设计（论文）I基于PLC的空气压缩机变频调速控制系统摘要空气压缩机（简称“空压机”）可以将取之不尽用之不竭的空气转换为动力，来推动机械设备转动，减少使用了石油、电力等资源。本设计主要目的是实现可编程控制器和变频器对空气压缩机组的主动控制。本方案通过变频器控制来达到对空气压缩机“一控多”的目的，可编程控制器可以达到变频器的工频与变频自由控制转换的现实需要，以及实现变频器对空压机的转换节制。系统通过压力传感器收集供气管道出口的压力值，经由变频器产生的4-20毫安标准控制信号，该信号又被送到可编程控制器的模拟输入端口，而后通过系统内部PID调节器算法逻辑运算产生控制信号，该信号又被送至变频器。在变频器操控当前机工作模式由变频转化成工频，而供压管道内压力值仍达不到安全工作要求时，则启动下一台空气压缩机，以此类推启动下一台。在变频器输出的电压频率已经变成了20HZ，此时供气管道内的气压量超过预先设定的气压值，系统封闭当前运行的机器，PLC转变操控另下一台。关键词：PLC，空压机，压力传感器，变频器洛阳理工学院毕业设计（论文）IIDesignsbasedonthePLCaircompressor’ssupervisorysystemABSTRACTThecompressor(theaircompressor)isacompressedgastoincreasegaspressureorgastransportationmachine.Aircompressoriswidelyusedinnearlyallindustrialandagricultural,defense,scienceandtechnology,civilandotherfields.Aircompressorsafetyprotectionfortheproductionofcoalminingenterprisesisveryimportant.ProgrammableLogicController(PLC)tothetraditionalrelaycontroltechnology,computercontroltechnologyandcommunicationtechnologyintegration,specificallydesignedforindustrialcontrolof.ThedesignusesPLCandfrequencyconvertertorealizetheautomaticcontrolofaircompressor.Theprogramusesinverteroftheaircompressordraggedmorecontrol,PLCtoachievetheinverterfrequencyandfrequencyconversioncontrol,andinverterswitchingcontrolofacompressorstation.CollectionsystemusingpressuresensorsOutletpressureairbag,transmitteroutputby4to20mAstandardsignaltothePLCanaloginputport,throughtheinternalPIDalgorithmPLClogicoperations,sendscontrolsignalstotheinverter.Whentheinvertertocontrolthecurrentmachinebytheinverterfrequency,whilethegaspressureisstillnotsatisfiedbythePLCcontrolinverterfrequencysoft-startthenextstationaircompressortorun,andthenclickOpen.Sothattheproductionsystemforgoodeconomicandsafetyperformance.KEYWORDS:PLC，aircompressor，Pressuretransducer，Inverter洛阳理工学院毕业设计（论文）III目录前言................................................................................................1第1章空气压缩机...........................................................................31.1空气压缩机的用途及其优点................................................31.2空气压缩机的分类...............................................................31.3螺杆式空气压缩机...............................................................41.3.1螺杆式空压机的应用.................................................41.3.2螺杆式空压机的运转原理..........................................41.3.3螺杆式空压机的特点.................................................51.4活塞式空压机.......................................................................6第2章可编程控制器（PLC）........................................................92.1PLC概述...............................................................................92.2PLC的基本组成....................................................................92.3PLC的基本工作原理..........................................................102.3.1可编程序控制器的工作方式....................................102.3.2可编程序控制器的工作过程....................................102.3.3可编程控制器的I/O响应时间.................................122.4PLC的分类.........................................................................13第3章PLC变频调速控制系统硬件电路的设计...........................143.1S7-200构件简介.................................................................143.1.1中央处理器CPU的功能..........................................143.1.2S7-200模板的主要特性............................................143.2元器件的选型.....................................................................153.2.1空气压缩机主要参数...............................................153.2.2变频器参数...............................................................153.2.3压力传送器的技术参数............................................163.2.4接触器简介...............................................................173.2.5热继电器选取...........................................................173.2.6报警装置...................................................................18洛阳理工学院毕业设计（论文）IV第4章PLC变频调速控制系统软件电路的设计...........................194.1设计PLC程序通用方法....................................................194.2PLC控制系统设计的一般步骤..........................................194.3PLCI/O点的分配表和外部接线图....................................21第5章PLC恒压变频调速控制系统设计......................................235.1控制系统恒压输出的方法.................................................235.2变频调速控制系统电气图.................................................245.3PLC变频调速控制系统空压机的切换方式.......................245.4PLC变频调速控制原理......................................................265.5计算机与PLC通信............................................................28结论..............................................................................................29谢辞................................................................................................30参考文献..........................................................................................31附录1..........................................................................................32附录2...........................................................................................33附录3...........................................................................................34主程序部分.................