资源描述:
《毕业论文 变逆器把直流电变成交流电.doc》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、摘要近年来,一些清洁高效的能源,如太阳能,风能,地热,核能等得到了较为广泛的应用和关注,其发电系统产生的是直流电流和电压,而许多负载都使用交流电,因此需要通过逆变器把直流电变成交流电。随着这些新能源发电系统的日益推广,逆变器的使用也越来越多。如何获得高质量的电流成为研究的焦点。由于对高频谐波的抑制效果明显好于L型滤波器,因此LCL滤波器在并网逆变器中应用越来越广泛,与传统的L滤波器相比,LCL滤波器可以降低电感量,提高系统动态性能,降低成本,在中大功率应用场合,其优势更为明显。文章首先对PWM逆变器的工作原理做了详细的介绍,并对基于LCL的滤波器,在ABC静
2、止坐标系,αβ静止坐标系和dq旋转坐标系中建立了数学模型。其次,文章讨论了LCL滤波器的参数设计方法,给出了系统LCL滤波器参数的设计步骤。最后,在详细阐述各元件的取值原则与计算步骤的基础上,给出了设计实例,并对所设计的逆变器进行了仿真验证,结果表明,根据该方案设计的控制器参数能够使三相并网逆变器安全、可靠运行且具有较快的动态响应速度。关键词:并网逆变器LCL滤波器有源阻尼无源阻尼,双闭环控制31AbstractInrecentyears,cleanandefficientenergysources,suchassolarenergy,windenergy,
3、geothermalenergy,nuclearenergyhasbeenwidelyusedandhasgainedwidespreadattention.ThepowersystemproducetheDCcurrentandvoltage,andmanyareusingtheACload,itneedinverterintoalternatingcurrenttodirectcurrent.Withtheincreasingpromotionofphotovoltaicpowergenerationsystems,theuseofinvertersis
4、moreandmore.Howtogetahighqualityofthecurrentbecomesthefocusofresearch.BecauseoftheinhibitoryeffectofhighfrequencyharmonicsisbetterthanL-typefilter,theLCLfiltergridinverteriswidelyapplied,comparedwiththetraditionalL-filter,LCLfiltercanreducetheinductanceimprovethesystemdynamicperfor
5、mance,reducecosts,inthehigh-powerapplications,itsadvantagesmoreapparent.ThispaperanalyzesthehighfrequencyPWMinverterprinciple,andthenpresentsathree-phaseABCcoordinatesanddqcoordinatesystemonthemathematicalmodelofLCL-filterconfiguration.Secondly,thearticlediscussestheLCLfilterdesign
6、parameters;parametersofthesystemaregivenLCLfilterdesignsteps.Finally,eachcomponentindetailtheprinciplesandcalculationstepsofthevaluebasedonthedesignexampleisgiven,andthedesignoftheLCLfiltersimulationresultsshowthat,accordingtothedesignofthecontrollerparameterscanmakethree-phaseinve
7、rterwithsafe,reliableoperationandhasafastdynamicresponsespeed.Keywords:Grid-connectedinverter,LCLfilter,Activedamping,passivedamping,Doubleclosedloopcontrol31目录摘要......................................................................IAbstract.........................................
8、........................II