简介:1.IntroductionAnobviousimprovementindesigningandmanufacturingtransformershasbeenachievedsincetheapplicationofpartialdis-charge(PD)testonpowertransformerswasaccepted.ChineseNationalStandardhasstipulatedthatPDtestisaroutineitemfortransformerswithratedvoltage220kVandabove.Manytransform-