基于PWM的功率信号源

哈尔滨工业大学本科毕业设计（论文）王新征VS李珊珊II摘要随着电力电子技术的飞速发展和对电气设备控制性能要求的提高，逆变技术的应用越来越广泛，相应对逆变电压的要求也越来越高。基于逆变电源形成的功率信号源不仅是能提供基准正弦信号源，而且是能提供带负载的大功率电压源。首先，PWM逆变器作为功率信号源的基础，本文介绍了PWM的产生机理，并对基于PWM产生的SPWM的输出进行了谐波的理论分析和仿真分析。通过对二者的比较可以得出对输出的谐波仿真分析与理论分析符合得很好。其次，结合SPWM的输出谐波分布，逐步设计了无源滤波器，满足了对输出的正弦波的波形质量的指标；通过比较各种逆变控制技术及本文限定的条件，选择了带积分饱和的PI控制器，针对该控制器进行了多次仿真分析，最终实现了对输出的正弦波幅值的指标；为了观察在以此正弦波为基波，叠加二到十二次中一种或多种谐波的输出波形情况，本文在满足基波输出幅值不变的前提下，进行了仿真，并给出了输出波形和基波幅值曲线。最后，本文重点介绍了晶闸管IGBT本身特性及其驱动和保护电路的设计原则。根据现有的实验设备，进行了实物实验，初步得到了开环滤波效果并给出了输出波形图及揭示了产生此波形图的原因。关键词PWM逆变器；谐波分析；无源滤波；PI控制器；IGBT哈尔滨工业大学本科毕业设计（论文）王新征VS李珊珊II-II-AbstractWiththerapiddevelopmentofPowerElectronictechnologyandrequirementsfortheimprovementsofelectricalequipment'scontrolperformance,theapplicationofinvertertechnologyisusedmoreandmorewidely.Correspondingly,itisrequiredmoreandmoreaboutthevoltageofthevoltage.Basedontheformationofthepowerinverter,powersourceisnotonlyareferencesinusoidalsignal,butalsoahigh-powervoltagesource.Firstofall,asthebasisofpowersource,PWMisfullyintroducedinthispaper.AstothevoltageoutputofSPWMwhichisproducedbasedonPWM,thepaperprovidestheharmonicanalysisinthetheoreticalwayandsomespectraldistributionswhicharetakenforexampleinthewayofsimulation.Itcanbedrawnthatthespectraldistributionsofsimulationissubjecttotheconclusionsofthetheoreticalanalysisaftercomparingthetwo.Secondly,takingSPWMoutputharmonicdistributionsintoaccount,thepapergraduallydesignsthepassivefilterinordertomakethequalityofthesinewaveoutputreachthereqirments.BycomparingthevariouscontroltechnologyofPWMinverterandthelimitconditions,thisarticlechoosesthePIcontrollerwithsaturationpoints.Afteranumberofsimulationanalysis,theamplitudeofthesinewavefinallymeetsthedemand.Inordertoobservetheoutputwaveformafterinjectingoneormoreoftheharmonicschosenfromthesecondharmonictothetwelfthharmonicintofundamentalcomponent,thepapercarriesoutthesimulationbasedontherealitythattheamplitudeoffundamentalcomponentremainsthesame.Thepaperalsogivestheoutputwaveformandthecurveofamplitudeofthefundamentalcomponent.Finally,thispaperfocusesoncharacteristicsofIGBTitselfandprinciplesofdesignofbothdrivecircuitandprotectioncircuit.Afteraphysicalexperimentaccordingtotheexistinglaboratoryequipment,itgetstheinitialeffectsoftheopen-loopfilter.Atlastthepapergivestheoutputwaveformandrevealsthereasonsforthiswave.KeywordsPWMinverter；harmonicanalysis；passivepowerinverter；PIcontroller；IGBT哈尔滨工业大学本科毕业设计（论文）王新征VS李珊珊III-III-目录摘要..................................................................................................................IAbstract..........................................................................................................II第1章绪论.....................................................................................................11.1课题背景.............................................................................................11.1.1课题来源..................................................................................11.1.2课题的研究目的和意义.............................................................11.2国内外研究现状..................................................................................11.3本文主要研究内容...............................................................................2第2章对PWM原理的理论与实验研究..........................................................42.1PWM控制的基本原理..........................................................................42.2PWM逆变电路及其控制方法...............................................................42.2.1计算法......................................................................................42.2.2调制法......................................................................................42.3对自然采样法进行数学推导.................................................................62.3.1进行分析谐波的重要性.............................................................62.3.2数学推导SPWM的谐波成分....................................................72.4对PWM输出波形进行仿真实验.........................................................102.4.1仿真算法的选择......................................................................102.4.2实验分析................................................................................112.5本章小结...........................................................................................14第3章含有死区的滤波输出..........................................................................153.1加入死区后的影响.............................................................................153.2滤波器的实现....................................................................................153.2.1滤波器的选择.........................................................................153.2.2完善滤波器.............................................................................163.3本章小结...........................................................................................20第4章加入闭环环节后分析..........................................................................214.1闭环控制技术综述及选择..................................................................214.2加入闭环控制基波输出....................................................