PWM控制直流调速系统毕业设计毕业论文.doc

www.yanziedu.comPWM控制直流调速系统设计摘要在电气时代的今天，电动机在工农业生产、人们日常生活中起着十分重要的作用。直流电机是最常见的一种电机，在各领域中得到广泛应用。研究直流电机的控制和测量方法，对提高控制精度和响应速度、节约能源等都具有重要意义。电机调速问题一直是自动化领域比较重要的问题之一。不同领域对于电机的调速性能有着不同的要求，因此，不同的调速方法有着不同的应用场合。本文基于PWM的双闭环直流调速系统进行了研究，并设计出应用于直流电动机的双闭环直流调速系统。首先描述了变频器的发展历程，提出了PWM调速方法的优势，指出了未来PWM调速方法的发展前景，点出了研究PWM调速方法的意义。应用于直流电机的调速方式很多，其中以PWM变频调速方式应用最为广泛，而PWM变频器中，H型PWM变频器性能尤为突出，作为本次设计的基础理论，本文将对PWM的理论进行详细论述。在此基础上，本文将做出SG3525单片机控制的H型PWM变频调速系统的整体设计，然后对各个部分分别进行论证，力图在每个组成单元上都达到最好的系统性能。关键词：直流调速；双闭环；PWM；SG3525；直流电机www.yanziedu.comDC-drivespeedsystemwithPWMABSTRACTInelectricaltimestoday,theelectricmotorintheindustryandagricultureproduction,thepeopledailylifeisplayingtheveryvitalrole.Thedirectcurrentmachineisthemostcommononekindofelectricalmachinery,obtainsthewidespreadapplicationinvariousdomains.Theresearchdirectcurrentmachinescontrolandthemeasuringtechnique,toincreasethecontrolprecisionandthespeedofresponse,thefrugalenergyandsoonhavetheimportantmeaning.Aproblemaboutspeed-modulationofDCmotorisveryimportantinthefieldautomatic.Therequeststotheeffectafterthespeed-modulationoftheDCmotoraredifferentindifferentfields.Then,differentspeed-modulationwaysareusingindifferentfields.ThispaperresearchesDC-drivespeedsystemwithadual-converteranddual-closed-loopbasedPWM,discussinganewcontrolmethodthatcombinesPWMwithDC-drive,designsappliesindirectcurrentmotorsdoubleclosedloopcurrentvelocitymodulationsystem.DCmotorisusedverygenerallybecauseitsspeed-modulationeffectisverygoodanditsspeed-modulationiseasilytoberealized.PWMtheoryisusedmostgenerallyamongthespeed-modulationways.ThetextwillintroducetheH-PWMwaymostly.WewilltrytodomodulationtotheDCmotorwithSG3525.Theimportanceofthetextisthepartswhicharecomposedthesystem.Anotherimportanceistheprinciplesofworkingabouteveryparts.Keyword:DCspeedregulation；Double-loop；PWM；SG3525；DCmoter；www.yanziedu.com目录摘要·····································································Abstract··································································前言·····································································1第1章直流调速系统的方案设计············································21.1设计技术指标要求···················································21.2现行方案的讨论与比较···············································21.3选择PWM控制调速系统的理由·······································41.4选择IGBT的H桥型主电路的理由·····································41.5采用转速、电流双闭环的理由·······································5第2章PWM控制直流调速系统主电路设计··································62.1主电路结构设计·····················································62.1.1PWM变换器介绍···························································62.1.2泵升电路·································································132.2参数设计···································································132.2.1IGBT的参数······························································132.2.2缓冲电路参数····························································142.2.3泵升电路参数····························································14第3章PWM控制直流调速系统控制电路设计·································153.1PWM信号发生器···························································153.1.1SG3525芯片的主要特点·············································153.1.2SG3525引脚各端子功能·············································163.1.3SG3525的工作原理·················································183.2转速、电流双闭环设计················································183.2.1转速、电流双闭环系统的组成·······································183.2.2转速、电流双闭环调速系统的静特性··································193.2.3电流调节器设计···················································223.2.4速度调节器设计···················································24www.yanziedu.com第4章系统实验验证······················································264.1系统结框图·························································264.2系统工作原理·······················································264.3系统单元调试·······················································274.3.1基本调试·························································274.3.2脉宽发生单元的整定···············································274.3.3转速反馈调节器、电流反馈调节器的整定······························284.4实验结果···························································284.4.1开环机械特性测试·················································284.4.2闭环机械特性测试·················································29结束语···································································30参考文献·································································31致谢·····································································32