Atransformertypeironcoresnubber,asaprotectivedeviceagainstthestraycapacitanceduringthebreakdowninEAST,isanalyzedindetail.Threekindsoftopologyarepresented.Thenwiththeanalysisforequivalentcircuit,therangesofthreekeyparameters,i.e.,secondarysideresistance,leakageinductanceandsnubberinductance,aredetermined.Byconsideringthesaturationofthemagneticmaterial,adesignprincipleisalsopresented.Anearly1:10coresnubberistested.Itisprovedthatahighpermeabilitycorewithsecondaryresistorcanrestrainthedischargecurrenteffectively.
