文档名：一种拓展模块化多电平变换器的光伏系统稳定运行范围的谐波补偿调制策略
摘要：由于阴影遮挡、损坏等问题,基于模块化多电平变换器的光伏系统中存在光伏(PV)输出功率不平衡的现象,会使高输出功率PV对应的子模块过调制.谐波补偿调制策略是解决该问题的一种常见方案,通过向高功率PV的子模块中注入谐波而避免子模块过调制,低功率PV的子模块(称为正常子模块)则需要补偿数量相同、相位相反的谐波,使桥臂内的谐波相抵消而不会造成桥臂电压和电流畸变.然而,在PV功率严重不平衡时,为了避免高功率PV的子模块过调制,现有谐波补偿调制策略需要注入的谐波过大,会超过正常子模块的补偿范围,使正常子模块出现过调制,导致桥臂电压和电流畸变,影响系统的稳定运行.该文提出一种新型谐波补偿调制策略,在高功率PV的子模块不发生过调制的前提下避免正常子模块过调制,保证系统的稳定运行.同时,该文对不同谐波补偿调制策略稳定运行范围进行了定性和定量评估,表明所提谐波补偿调制策略能在更多PV功率不平衡工况下稳定运行.通过仿真与实验验证谐波补偿调制策略在模块化多电平变换器光伏系统中的可行性与理论分析的正确性.
Abstract：Harmoniccompensationmodulation(HCM)strategiesarecommonlyusedsolutionsforphotovoltaic(PV)powerimbalanceconditionsofamodularmultilevelconverter-basedphotovoltaicsystem(MMC-PVS).Themaximumequivalentfundamental-frequencymodulationindexisextendedto1.273,andthesystem'sstableoperationrangeisexpanded.AccordingtotheprincipleofHCMstrategy,harmonicsareinjectedintosubmodules(SMs)withhigh-powerPVstopreventover-modulation,andtherestofSMscorrespondingtolow-powerPVs(referredasnormalSMs)compensateforthesameamountofoppositeharmonicstoavoiddistortionsonphasearmvoltagesandcurrents.However,existingHCMstrategiesmayleadtoover-modulationonnormalSMsanddistortionsonphasearmvoltagesandcurrentswhenfacingseverePVpowerimbalance.ThispaperproposesanovelHCMstrategytopreventtheover-modulationonSMsandnormalSMssimultaneously.TheprincipleofHCMstrategyisintroduced,andanHCMstrategyforexpandingthesystem'sstableoperationrangeisproposed.Then,relationshipsbetweentheinjectedharmonicamplitudeandequivalentfundamental-frequencymodulationindexinover-modulationSMareanalyzed.Onthisbasis,operationconstraintsofHCMstrategiesinMMC-PVSarederivedasthecriteriaofsystemstableoperation.Combinedwiththeconceptsofstableoperationspace(SOS)andstableoperationfactor(SOF),stableoperationrangesofdifferentHCMstrategiesareevaluatedqualitativelyandquantitatively.TheresultsshowthattheSOFoftheproposedHCSstrategyisimprovedbyupto71.57％,whichis4.61timesthatofthetraditionalsinusoidalpulsewidthmodulation(SPWM)strategyandsignificantlylargerthanthoseofmostexistingHCMstrategies.WhenPVpowerisslightlyimbalanced,theproposedHCMstrategyandexistingHCMstrategiesachievesmoothtransitionsundervariousworkingconditionswithnegligiblecurrentdistortion.UnderseverePVpowerimbalance,theproposedHCMstrategymaintainssystemstability,whileotherHCMstrategiesexhibitcurrentdistortions.TheHCMstrategiescannormallyoperatewhenthenumberofSMsofeachphasearmis3and4,respectively.ComparedwiththeexistingHCMstrategies,theproposedHCMstrategyextendsthestableoperationrangeofMMC-PVS,avoidingover-modulationonnormalSMsandSMswithhighpowerPVssimultaneously.TheHCMstrategiesmaintainthenormaloperationofMMC-PVSwithoddorevennumbersofSMsineachphasearmunderPVpowerimbalanceconditions.TheproposedHCMstrategycanalsobeappliedincascadedH-bridgeconverter-basedPVsystemswiththecapabilityofstableoperationrangeextension.
作者：潘尧 孙孝峰 蔡瑶 李昕 赵巍Author：PanYao SunXiaofeng CaiYao LiXin ZhaoWei
作者单位：燕山大学电力电子节能与传动控制河北省重点实验室秦皇岛066004
刊名：电工技术学报
Journal：TransactionsofChinaElectrotechnicalSociety
年，卷(期)：2024, 39(4)
分类号：TM615
关键词：模块化多电平变换器 功率不平衡 谐波补偿调制策略 过调制 稳定运行
Keywords：Modularmultilevelconverter powerimbalance harmoniccompensationmodulation(HCM)strategy over-modulation stableoperation
机标分类号：TM464TM7TM351
在线出版日期：2024年3月5日
基金项目：河北省重点研发计划项目，河北省自然科学基金重点项目一种拓展模块化多电平变换器的光伏系统稳定运行范围的谐波补偿调制策略[
期刊论文] 电工技术学报--2024, 39(4)潘尧 孙孝峰 蔡瑶 李昕 赵巍由于阴影遮挡、损坏等问题,基于模块化多电平变换器的光伏系统中存在光伏(PV)输出功率不平衡的现象,会使高输出功率PV对应的子模块过调制.谐波补偿调制策略是解决该问题的一种常见方案,通过向高功率PV的子模块中注入...参考文献和引证文献
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一种拓展模块化多电平变换器的光伏系统稳定运行范围的谐波补偿调制策略 A Harmonic Compensation Modulation Strategy for Extending Steady Operation Range of Modular Multilevel Converter-Based Photovoltaic System
一种拓展模块化多电平变换器的光伏系统稳定运行范围的谐波补偿调制策略.pdf
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