改进的负序电流扰动孤岛检测方法.pdf

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1、2015年11月PowerElectronicsNOV．2015改进的负序电流扰动孤岛检测方法吴铁洲，熊金龙，曾艺师，张琪(湖北工业大学，太阳能高效利用湖北省协同创新中心，湖北武汉430068)摘要：工程中采用三相光伏并网系统负序电流扰动法进行孤岛检测。会由于负载变化和浪涌电流等因素造成公共连接(PCC)电压出现负序高频分量而导致孤岛误判。在研究负序电流扰动下负序分量提取和孤岛判断原理基础上，利用离散小波变换对时域信号高频分量变化有良好解析能力的特点，实时检测分析PCC电压高频分量并判断孤岛效应。基于Matlab／Si

2、mulink建立并网系统模型，在逆变器输出功率与负载输入功率相匹配的情况下进行孤岛模拟试验，应用Daubechies小波对PCC电压信号进行量化分析，选择出有效的小波高频信号域值作为孤岛检测量进行孤岛检测。试验结果表明该方法能快速、有效地检测到孤岛，并能有效防止对伪孤岛现象的误判。关键词：光伏并网；负序电流扰动；孤岛检测中图分类号：TM615文献标识码：A文章编号：1000—100X(2015)11O36一o4ImprovementofNegativeSequenceCurrentDisturbanceBasedonI

3、slandingDetectionMethodWUTie—zhou，XIONGJin-long，ZENGYi—shi，ZHANGQi(HubeiUniversityofTechnology，HubeicollaborativeInnovationCenterforHigh—efficiencyUtilizationofEnergy，Wuhan430068，China)Abstract：Thenegativesequencecurrentdisturbancemethodofthree—phasephotovohaicg

4、ridconnectedsystemisusedtodetecttheisland．Thenegativesequencehigh—frequencycomponentsincommonconnectionpoint(PCC)voltagewhichcausedbytheloadvariationandthesurgecurrentwillleadtoislanddetectionmistake．Basedonthetheoreti—calresearchofnegativesequencecomponentextra

5、ctionandislandsjudgmentprinciple，usingdiscretewavelettrans-formwhichhasagoodanalyticalcharacteristicsfortimedomainsignalfrequencycomponentchangestocapturethePCCvoltagehigh—frequencycomponentsanddetermineislandeffectinreal—time．Themodelofdconnectionsystemisestabl

6、ishedbyMatlab7．10／Simulink，whentheinverteroutputpowertomatchwiththeloadinput，theislandsimu—lationtestiscarriedout，andtheDaubechieswaveletisusedtoanalyzethePCCvoltagesigna1．Theefectivewavelethigh-frequencysignalregionischosenastheislanddetectionrate．Thesimulation

7、resultsprovethismethodcande—tectsisland，andpreventthepseudo—islandphenomenonoffalsepositivesquicklyandeffectively．Keywords：photovohaicgrid-connected；negative—sequencecurrentdisturbance；islandingdetectionFoundationProject：SupportedbyScientificResearchFoundationof

8、HubeiProvincialDepartmentofEducation(No．D20121403)；FoundationofScienceandTechnologyDepartmentofHubeiProvince(No．2010CDB05802)1引言用对象需含有功率控制环节，且检测时间受功率外环的影响：白适应相位偏移法能快速