保护用电流互感器铁心饱和相关问题的研究

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1、华北电力大学（北京）博士学位论文保护用电流互感器铁心饱和相关问题的研究姓名：张新刚申请学位级别：博士专业：电工理论与新技术指导教师：王泽忠20051201华北电力大学博士学位论文摘要最小二乘法的单步运算量很小，因此，新补偿方法非常适合于实时实现。而且，新方法采用新观测数据修正以前的参数估计结果，保证了采用一阶泰勒级数逼近一次电流衰减直流分量的准确性。另外，由于一次电流参数的估计结果是总体意义上的最优解，因此，新方法具有很强的抗干扰能力。7．采用DSP+CPLD的硬件结构开发了嵌入式系统；实现了铁心饱和检测的波形

2、奇异法和二次电流畸变补偿的RLS方法。实验结果表明，在基于DSP的嵌入式系统内，波形奇异法和RLS方法能够有效地发挥作用，且程序具有良好的实时性。关键词：电流互感器，铁心，饱和，奇异性，神经网络，实时最小二乘法II兰j!皇垄查堂堡主堂些堡苎塑至AbstractWhenfaulthappens，theprimarycurrentofpowersystemmaybealotoftimesoftheloadcurrent，andalwayshasDCtransientcomponent．Inthiscondition

3、，themagneticcoreofPtypeprotectivecurrenttransformer(CT)willbecomesaturated，whichcansesthedistortionofsecondarycurrentandaffectstheoperationofprotectionrelayandothersecondaryequipments．ThispaperdoescomprehensiveresearchontheproblemsaboutCTmagneticcoresaturati

4、on．themaincontentsare舔follows．1．AnewCTdigitalmodelbasedonPreisachtheoryispresented．BytheapplicationofPreisachtheory,thispaperavoidstheconflictbetweenworkloadandsimulationprecisionintheworkofCTmodeling．ThenewCTmodelcallsimulatemagnetizingprocessofmagneticcore

5、preciselybyonlysomeeasilyacquiredparameterssuchaslimitinghysteresisloop，magneticcoresizeandCTratio，andgetprecisesimulationresultsofsecondarycurrent，magnetizingcurrent，fluxdensity．2．AnalysisisperformedabouttheeffectivescopeofnewCTmodelandsomeotherCTmodelsthat

6、mayalwaysbeusedinengineering．Basedonthis，presentssomesignificantfeaturesaboutCTmodeling：(i_)Simulatingthemagnetizingtrajectoryinthesaturationscopepreciselyisnecessarytoget啦蛳secondarycurrentwaveformwhenthemagneticcoreissaturated；@Simulatingthemagnetizingproce

7、ssofmagneticcorepreciselyisnecessaryinthere-closeprocess．3．AnalysisabouttheeffectscausedbysomeparametersonCTsaturationconditionisperformed．Theseparametersareprimarycurrent，secondaryload，rema,nencc，materialofmagneticCOre，areaofcrosssection，turnsofcoilandCTsca

8、le．Pointsoutforthefirsttimethattheeffectscausedbyremanencewilldecreaseasthetotaltimeofsaturationincreases．4．Forthefirsttime，presentsanewsaturationdetectionmethodbasedonthesingularcharactersofsec