文档名：基于不同时段内积投影的灵活接地系统高阻故障选线方法
摘要：针对灵活接地配电系统在发生高阻故障时,无法实现准确选线的问题,通过分析灵活接地系统故障特征得出中性点小电阻投入后故障馈线与健全馈线在零序电流幅值上存在差异,同时,小电阻投入后母线零序电压发生明显降低.由此,提出一种基于中性点小电阻投入前后不同时段下计算内积投影的高阻故障选线方法.首先,将小电阻投入后各馈线零序电流对投入前的母线零序电压做内积投影,由此构建判据1;其次,将小电阻投入后各馈线零序电流对投入前的中性点电流做内积投影,由此构建判据2;最后,当判据1与判据2判定的故障馈线结果一致时,得到故障馈线.大量仿真实验表明,在非同步采样、数据缺失与电弧等故障工况下,该方法具有良好的稳定性,与现有方法对比可知,该文方法判定时间短,且适应电流互感器反接工况.
Abstract：Highimpedancefaultsareacommonformofdistributionnetworkfaults,accountingforabout5%to10%ofmediumvoltagedistributionnetworkfaults,oftenaccompaniedbyarcing,whichcaneasilycausesafetyhazards.Duetotheweakfaultcharacteristicsofhighimpedancefaults,mostfaultyfeederdetectionmethodsonlyhavehighaccuracyforlow-impedancefaults.Thisisinsufficienttosupporttheprincipleofproximityandfastisolationofgroundfaults.Recently,somehighimpedancefaultlineselectionmethodshavebeenproposed,butmostofthemsufferfromcomplexprinciples,singlecriteria,andequipmentmeasurementaccuracythatdoesnotmeetthedemand.Toaddresstheseproblems,thispaperproposedhighimpedancefaultlineselectionmethodsbasedoninnerproductprojectionofdifferenttimeperiodsforflexiblegroundingsystems.Itcanaccuratelydetectthefaultyfeederathighimpedancefaultsthroughthecharacteristicquantitiesofvoltageandcurrentbeforeandaftersmallresistanceinput.Firstly,theinnerproductprojectionofeachfeeder'szero-sequencecurrentaftersmallresistanceinputontothebuszero-sequencevoltagebeforesmallresistanceinputisconstructedascriteria1.Secondly,theinnerproductprojectionofeachfeeder'szero-sequencecurrentaftersmallresistanceinputontotheneutralpointzero-sequencecurrentbeforesmallresistanceinputisconstructedascriteria2.Finally,whentheresultsofthefaultyfeederdeterminedbycriterion1andcriterion2arethesame,thefinalfaultyfeederresultisobtained.Thefaultdetectionmethodfullyusesthefaultcharacteristicsunderdifferenttimeperiods,solvestheinfluenceofbuszero-sequencevoltagedropaftersmallresistanceinputandasinglecriteriononthedetectionaccuracy,andgreatlysimplifiesthefaultyfeederdetectionprinciple,resultinginahighlyaccuratefaultyfeederdetectionmethod.Thesimulationresultsusingaflexiblegroundingsystemshowthat.Firstly,thefaultyfeedercanbeaccuratelydeterminedunderhighimpedancefaultconditionsconsideringdifferentfaultfeeders,faultdistance,faultinitialphaseangle,overcompensation,groundresistanceandnoiseinterference.Second,consideringasynchronoussamplingandmissingdata,whereasynchronoussamplingisupto11msanddatamissingisupto85%,theproposedmethodstillhasgoodstability.Then,theaccuracyoftheproposedmethodisverifiedunderthreearcparameters.Finally,theproposedmethodiscomparedwithtwoflexiblegroundingsystemmethodsunderfourcomplexoperatingconditions,whereacurrenttransformerreversalwasconsidered,theproposedmethodtakestheshortesttimeof0.05s,andthereisnomisjudgment.Thefollowingconclusionscanbedrawnfromthesimulationanalysis:(1)Comparedwithexistingmethods,theproposedmethodgreatlysimplifiestheprincipleofdetectioncriterionandeffectivelyovercomesthebuszero-sequencevoltagereductionproblem.Therefore,itisappropriatetousedifferenttimeperiodsoffaultcharacteristics.(2)Theproposedmethodcombinestheinnerproductprojectionofeachfeedercurrentaftersmallresistanceinputontothebusvoltageandneutralpointcurrentbeforesmallresistanceinput.Itusestwotypesofcriteria,bothofwhichcomplementeachothertoimprovetheaccuracyoffaultfeederdetermination.(3)Theproposedmethodismorecapableofadaptingtocomplexworkingconditions,andthecalculationtimeofthecriterionisshort.Inaddition,thefaultyfeedercanstillbeaccuratelydeterminedwhenthecurrenttransformerisreversed.
作者：王晓卫 刘伟博 郭亮 梁振锋 Author：WangXiaowei LiuWeibo GuoLiang LiangZhenfeng
作者单位：西安理工大学电气工程学院西安710048国网江西省电力有限公司电力科学研究院南昌330000
刊名：电工技术学报
Journal：TransactionsofChinaElectrotechnicalSociety
年，卷(期)：2024, 39(1)
分类号：TM77
关键词：灵活接地系统 高阻故障 不同时段 内积投影
Keywords：Flexiblegroundingsystems highimpedancefault differenttimeperiods innerproductprojection
机标分类号：TM711TM452TM862
在线出版日期：2024年1月18日
基金项目：国家自然科学基金，国家自然科学基金，国网江西省电力有限公司科技项目，国网江西省电力有限公司科技项目基于不同时段内积投影的灵活接地系统高阻故障选线方法[
期刊论文] 电工技术学报--2024, 39(1)王晓卫 刘伟博 郭亮 梁振锋针对灵活接地配电系统在发生高阻故障时,无法实现准确选线的问题,通过分析灵活接地系统故障特征得出中性点小电阻投入后故障馈线与健全馈线在零序电流幅值上存在差异,同时,小电阻投入后母线零序电压发生明显降低.由此,提...参考文献和引证文献
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基于不同时段内积投影的灵活接地系统高阻故障选线方法 High Impedance Fault Line Selection Method Based on Inner Product Projection of Different Time Periods for Flexible Grounding Systems
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