H桥级联SVG的载波移相调制技术研究.pdf

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1、第5l卷第4期电测与仪表VO1．51No．42014生2月25日ElectricalMeasurement&InstrumentationFeb．25．2014H桥级联SVG的载波移相调制技术研究常志琴，孙丽玲，谢欢(1．华北电力大学电气与电子工程学院，河北保定071003；2．华北电力科学研究院有限责任公司，北京100045)摘要：级联多电平高压大容量变流器已广泛应用于电力系统中，载波移相式正弦脉宽调制(CPs—SPwM)技术非常适用于大功率变流器场合。文中分别介绍了双极性cPs—SPWM调制方法和单极倍频CPS—SP

2、WM调制方法，并基于PSCAD／EMTDC软件搭建仿真模型，采用频谱分析方法对其进行对比，结果表明采用双极性CPS—SPWM调制方法输出电压的最低次谐波群出现在Ⅳ(Ⅳ是指每相级联单元数)倍的载波频率附近，其等效开关频率提高了Ⅳf立，采用单极倍频CPS—SPWM调制方法的输出电压的最低次谐波群出现在2Ⅳf立的载波频率附近，其等效开关频率提高了2^倍，因此采用单极倍频CPS—SPWM调制方法其输出波形更接近正弦波，具有更好的消除谐波的特性。关键词：大功率变流器；双极性CPS—SPWM；单极倍频CPS—SPWM；开关频率；仿真

3、模型中图分类号：TM933文献标识码：A文章编号：1001—1390(2014)04—0066—07ResearchonHBridgeCascadedSVGwithCarryPhaseShiftingTechnology112CHANGZhi—qin，SUNLi-ling，XIEHuan(1．NorthChinaElectricPowerUniversityInstituteofElectricalandElectronicEngineering，Baoding071003，Heibei，Chnia．2．NorthChi

4、naElectricPowerResearchInstitute，Beijing100045，China)Abstract：Cascademultilevel，highvoltageandlargecapacityinvertershavebeenwidelyusedinelectricpowersystems．Carrierphaseshiftedsinusoidalpulsewidthmodulation(CPS—SPWM)techniqueisverysuitableforthehighpowerinverter．

5、Inthepaper，bipolarCPS-SPWMandsinglepoledoublefrequencyCPS—SPWMmodulationmethodarepresentedrespectively，andasimulationmodelbasedO13PSCAD／EMTDCsoftwareisbuilt．Comparativeanalysisforthesetwomethodsismadebyadoptingfrequencyspectrumanalysismethod．Simulationresultshave

6、provedthatthelowestharmonicsoftheoutputvoltagearecentralizedneartheNtimesofthecarrierfrequency，andtheequivalentswitchfrequencyisimprovedbyN(NisthenumberofthecascadeSVGforeachphase)timesbyadoptingbipolarCPS—SPWM．Thelowestharmonicsoftheoutputvoltagearecentralizedne

7、arthe2Ntimesofthecarrierfrequency，andtheequivalentswitchfrequencyisimprovedby2NtimesbyadoptingsinglepoledoublefrequencyCPS—SPWM．Therefore，thesinglepoledoublefrequencyCPS—SPWMmodulationmethodisbettertoeliminatetheharmonics，anditsoutputvoltagefitssinewavebetter．Key

8、words：high-powerconverters，bipolarCPS-SPWM，singlepoledoublefrequencyCPS—SPWM，switchfrequen—cy．simulationmodel0引言统电压低时调节能力~Lsvc强；SVG连接电抗小，对静止无功补偿装置一直是国内外电力行业重点电