毕业设计论文示范(两万字)

I摘要随着变频调速技术的发展，变频器调速已成为交流调速的主流，在化纤、纺织、钢铁、机械、造纸等行业得到广泛的应用。变频器控制面板上配有键盘及液晶显示窗口，但只能实现手工操作，为了进行自动化控制，因此引进单片机技术，实现单片机与变频器之间的数据通信，提高变频器的控制能力和控制范围。利用单片机组成的变频调速控制器，可以实现从低频(1～2Hz)起动到50Hz，可以消除以往工作频率50Hz直接起动对电机的冲击，延长电机的使用寿命，同时由于变频器的输出电压可以自适应调节，使负载电机可以工作在额定电压以下，不仅节能且可延长电机的使用寿命。本文将介绍基于单片机控制的变频调速系统的设计，通过此系统控制变频器，由变频器去控制电机的转动，实现对矿井中主、副井提升机的模拟，以便演示矿井的工作过程，能够以手动和自动两种方式实现一次过程的五个状态，实时显示主、副井的深度。关键词：变频调速，单片机，电机，提升机IIAbstractWithVVVFtechnologydevelopment,thefrequencyconverteradjustvelocityinexchangehasbecomethemainstream,anditobtainsthewidelyapplicationinsomeprofessions,suchaschemicalfiber,textile,steelandiron,machinery,papermakingandsoon.Therearekeyboardandliquidcrystaltodemonstratewindowonthefrequencyconverter'scontrolofface,butitcanonlyrealizemanualoperation,forrealizetheautomaticcontrolsoweintroduceSCMtechnology,astheresult,betweenMCUandthefrequencychangerdatacommunicationcanenhancethecontrolabilityandareaofthefrequencychanger.ComposedwithSCMoftheVVVFcontrollerbeingabletostartfromlowfrequency(1~2Hz)to50Hz.Itcanremovetheworkingbandinthepast50Hzstarttheimpingementtotheelectricmotordirectly.Atthesametime,sincethefrequencyconvertercanadjustoutputvoltagefitinwithitself,makingloadsmotorcanworkunderfixedvoltage,whichnotonlyenergyconservationbutalsoprolongthelifetimeofthemotor.ThepaperwilldescribethedesignoftheVVVFsystembasedontheSCMcontrolled,andthroughthissystemscontrolfrequencyconverter,thencontrolthemotorrotating,realizationsimulationtominepitinhostandvicewell,inordertodemonstratetheprocessofminepit,itcanachieveaprocessofthefivestatesbybothmanualandautomaticway,realtimedisplayhostandvicewelldepth.Keywords:VVVF，Single-ChipComputer，Motor，ElevatorIII目录1绪论······················································································11.1选题的目的和意义···································································11.2国内外研究综述······································································21.3需求分析···············································································31.4可行性分析············································································41.5开发工具简介·········································································51.5.1KEILCx51·······································································61.5.2PROTEUS··········································································72系统硬件设计··············································································92.1单片机控制系统······································································92.2变频器电路··········································································122.3数/摸转换电路·····································································142.4信号检测电路·······································································152.5电源电路·············································································173系统软件设计············································································183.1主控制模块设计····································································183.2键盘模块设计·······································································183.3显示模块设计·······································································193.416进制转十进制BCD的算法····················································223.5频率计算程序·······································································233.6速度计算程序·······································································243.7深度计算程序·······································································244系统测试··················································································254.1硬件测试·············································································254.2软件测试·············································································265问题及展望···············································································31IV5.1已经解决的问题及解决方案·····················································315.2系统中的不足及展望······························································32致谢·························································································33参考文献······················································································34附录1··························································································35附录2··························································································3611绪论1.1选题的目的和意义随着变频调速技术的发展，变频器调速已成为交流调速的主流，在化纤、纺织、钢铁、机械、造纸等行业得到广泛的应用。变频器是基于电子技术、计算机技术和自动控制理论发展起来的电子电气设备，用户可以直接操作变频器上配有的手工操作键盘，设定运行参数，发出命令，但毕竟操作复杂，容易出错。为了方便大数用户的使用，必须寻求另外的解决方式，采用单片机对电动机进行控制成为实现电动机数字控制的最常用的手段。随着单片机技术的日新月异，特别是高性能价格比的单片机涌现，使得许多控制功能及算法可以采用软件技术来完成，为电动机的控制提供了更大的灵活性。随着电力电子技术的日益发展和PWM控制技术的成熟，利用单片机组成的变频调速控制器可以实现从低频(1～2Hz)起动到50Hz，可以消除以往工作频率50Hz直接起动对电机的冲击，延长电机的使用寿命，同时由于变频器的输出电压可以自适应调节，使负载电机可以工作在额定电压以下，不仅节能且可延长电机的使用寿命。基于单片机控制的变频调速系统是河南理工大学工矿技术开发公司委托开发的一个项目，这个项目主要用于对矿井中主、副井提升机的模拟，以便演示矿井的工作过程，要求以手动和自动两种方式实现，并能实时显示主、副井提升机的深度。为此设计的控制系统，以单片机为核心，在键盘、显示和数-模转换当中采用模块化设计，这样不但易于编程，而且方便对系统的整体调试。项目的开发目的主要是用作教学模型，如果实现的效果好，会非常便于演示，能够很好的配合教师教学，也能帮助学生更好地理解