资源描述:
《基于改进小波变换方法的电力系统》由会员上传分享,免费在线阅读,更多相关内容在工程资料-天天文库。
1、基于改进小波变换方法的电力系统低频振荡参数辨识*孙正龙1,蔡国伟1,王雨薇2,刘铖1(1.东北电力大学电气工程学院,吉林吉林132012;2.国网吉林省电力有限公司吉林供电公司,吉林吉林132012)摘要:基于多点量测数据的低频振荡模态参数辨识方法具有辨识精度高,覆盖模态信息全的特点,但是该方法存在数据量增大,计算时间冗长的问题。针对上述问题,本文将基于数据缩减技术的改进小波变换参数识别方法应用于电力系统低频振荡参数辨识中。该方法通过对发电机出口有功功率信号的正功率谱密度矩阵进行奇异值分解,有效识别系统的模态阶数。利用奇
2、异值分解将待辨识信号的协方差信号进行数据缩减,充分保留信号的信息量,从而在保证计算合理及精度的前提有效地减少待辨识的数据量,进而利用连续Morlet小波变换识别电力系统低频振荡参数。通过对4机2区域系统和EPRI-36节点系统进行算例对分分析,结果表明改进的小波变换方法能够有在准确提取电力系统低频振荡模态参数的前提下,有效减少计算所用数据量,提高计算效率。关键词:低频振荡;模态辨识;Morlet小波变换;数据缩减中图分类号:TM93文献标识码:B文章编号:1001–1390(2016)00–0000–00Extracti
3、onandanalysisParameteridentificationofunderlowfrequencyoscillationusingbasedonimprovedwaveletalgorithmtransforminpowersystemSunZhenglong1,CaiGuowei1,WangYuwei2,LiuCheng1(1.SchoolofElectricalEngineering,(1.NortheastDianliUniversity,SchoolofElectricalEngineering,Ji
4、lin132012,Jilin,China.2.2.StateGridJilinShengElectricPowerSupplyCompany,Jilin132010,Jilin,Jilin,China))Abstract:Theapproachofmodesextractingparameteridentificationunderoflowfrequencyoscillationmodesbasedonmulti-measurementdata,hastheadvantagesofhighprecisionandre
5、liability.However,thehugeamountofdataandlongcalculationtimehaveamountsofdataandlongcalculationtimehavelimitedtheapplicationoftheapproach.Inthispaper,arobustonlineapproachbasedonimprovedwavelettransformisproposedtoextracttheparametersofdominantoscillationmodefromw
6、ide-areameasurementsinpowersystemdominantoscillationmodefromwide-areameasurements.Thesingularvaluedecomposition(SVD)isusedtoanalyzethepositivepowerspectrummatrixofgeneratorelectromagnetismpowertodeterminetheordersofoscillationmodes.Toreducethecovariancesignals,th
7、eSVDisusedtodiminishtheamountofdatawhichisinvolvedintheextraction.Finally,themodalparametersareextractedfromeachmodeofreducedsignalsusingtheimprovedwaveletalgorithmtransforminthespecifiedfrequencyranges.Throughthestudyof4-generator2-areaandEPRI-36testsystems,itis
8、verifiedthattheproposedimprovedwaveletalgorithmtransformcouldextracttheaccurateoscillationparameterswithreducedcomputationdatasizetoincreaseimprovecalculatione