文档名：基于电容自然充电换相的混合式直流断路器设计与仿真
摘要：以晶闸管作为主断器件是降低混合式直流断路器造价和技术难度的手段之一,电容电压是此类直流断路器能够顺利开断直流故障的关键影响因素.现有结构中电容大多为预充电型,但预充电方式和电容电压的维持较为复杂.因此,该文提出一种基于电容自然充电换相的混合式直流断路器,利用母线电压与预充电电容的电压差值实现电容的预充电和电容电压的自动维持,从而保证断路器的开断能力.此外该断路器还具备二次开断能力,可以满足极短时间内重复开断的需求.针对所提断路器的工作过程和元器件参数进行了详细的理论推导,基于PSCAD/EMTDC建立单端等效和四端柔性直流电网模型验证了所提结构的适用性.最后与其他方案进行比较,结果表明,所提方案在开断速度、电容预充电方式和二次开断方面具备一定优势.
Abstract：HybridDCcircuitbreakersbasedonIGBTasthemainbreakingdeviceareexpensive,whichlimitsthelarge-scaleapplicationofhybridDCcircuitbreakers.ThyristorisoneofthemeanstoreducethecostandtechnicaldifficultyofhybridDCcircuitbreakerasthemainbreakingdevice.ThistypeofhybridDCcircuitbreakergenerallycombinespre-chargedcapacitortocompletethebreakingtask,butthepre-chargemodeoftheexistingstructurecapacitorandthemaintenanceofthecapacitorvoltagearemorecomplicated.Therefore,thispaperproposesahybridDCcircuitbreakerbasedonthenaturalchargingcommutationofthecapacitor.TheinitialenergystorageofthecapacitorandtheautomaticmaintenanceofthecapacitorvoltagearerealizedbyusingthevoltagedifferencebetweentheDCbusandthecapacitor,soastoensurethebreakingabilityofthecircuitbreaker.Aftertheinterruption,thecapacitorvoltagecanberechargedagainwhetherthelinefaultisrestoredornot,whichcanmeetthedemandofsecondaryinterruptioninashorttime.Firstly,thetopologyandworkingprocessoftheproposedtopologyareintroducedandanalyzed.Accordingtothefunctionofeachbranch,theproposedbranchisnamedasthemainbranch,thetransferbranchcomposedofthyristors,thecapacitornaturalchargingbranch,thecapacitorcommutationbranch,theenergyabsorptionbranch.Thereisnochargingswitchinthecapacitornaturalchargingbranch,whichisthekeytorealizetheinitialenergystorageofthecapacitorandtheautomaticmaintenanceofthecapacitorvoltage,alsodetermineswhethertheproposedcircuitbreakercansuccessfullybreaktheDCfault.Thentheparametersofthemaincomponentsintheabovebranchesaredesigned,andthegeneralprinciplesofparameterdesignandtherecommendedrangeofvaluesaregiven.ThefollowingtwopointsdeterminewhethertheproposedschemecansuccessfullyandreliablybreaktheDCfault:(1)Thepeakvalueoftheoscillatingcurrentgeneratedbythecapacitorcommutationbranchneedstobegreaterthanthepeakvalueofthefaultcurrent.(2)ThediodeconductiontimetDinthetransferbranchneedstobegreaterthanthethyristorturn-offtimetq.Forthebenefitofverifytheapplicabilityoftheproposedstructure,asingle-terminalandafour-terminalDCgridmodelareestablishedbasedonPSCAD/EMTDCtosimulatetheunipolarmetalgroundingfaultatthecircuitbreakeroutlet.ThesimulationresultsshowthattheproposedstructurecanisolatetheDCsidefaultquickly,andthenumberofdevicesisgivenaccordingtothestressofthedeviceduringthebreakingprocess.Ifthethyristorwithaparameterof4.5kV/3.5kAisselected,3110thyristorsareneeded.Finally,bycomparingwithseveralschemesthathavebeenproposed,thefollowingconclusionsaredrawn:(1)TheproposedstructurereplacesthemoreexpensiveIGBTwithathyristor,andtheeconomyisimprovedtoacertainextent,andthebreakingspeedisfaster.(2)Theinitialstorageofcapacitorandthemaintenanceofcapacitorvoltagecanbeachievedwithoutadditionalcontrolandequipment.(3)Afterfaultisolation,thecapacitorcanbechargedagaintomeettheneedsofrepeatedbreakinginashorttime.
作者：范兴明 李涛 张鑫Author：FanXingming LiTao ZhangXin
作者单位：桂林电子科技大学机电工程学院桂林541004
刊名：电工技术学报 ISTICEIPKU
Journal：TransactionsofChinaElectrotechnicalSociety
年，卷(期)：2024, 39(11)
分类号：TM561
关键词：混合式直流断路器 晶闸管 预充电 二次开断
Keywords：HybridDCcircuitbreaker thyristors pre-charge secondarybreakingcapacity
机标分类号：TM721TH137TN911-34
在线出版日期：2024年6月18日
基金项目：国家自然科学基金，广西自然科学基金项目基于电容自然充电换相的混合式直流断路器设计与仿真[
期刊论文] 电工技术学报--2024, 39(11)范兴明 李涛 张鑫以晶闸管作为主断器件是降低混合式直流断路器造价和技术难度的手段之一,电容电压是此类直流断路器能够顺利开断直流故障的关键影响因素.现有结构中电容大多为预充电型,但预充电方式和电容电压的维持较为复杂.因此,该文...参考文献和引证文献
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基于电容自然充电换相的混合式直流断路器设计与仿真 Design and Simulation of Hybrid DC Circuit Breaker Based on Capacitor Natural Charging Commutation
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