This paper analyzes the reason of transformer residual flux resulting from the inherent hysteresis in the ferromagnetic material, and presents a novel method to detect transformer residual flux based on the time-current curve. Through theSpower transformer primarySloadSthe same amplitudeSpositive and negativeSSvoltage sourceSto charge and discharge,Sestablishing a “time-current” curveSto determineSwhether theStransformerShasSresidual flux andSpolarity of residual flux.SMATLAB simulation andSexperiment test and verify transformer residual flux detection method based on the time-current curve can accurately measure whether the transformer
