3Hindle P J, Robinson N, Wixon A. Coping with abnormal flux conditions when applying transformer protection [C]. Developments in power system protection,1997, sixth international conference on (Conf Publ No.434). [s 1],1997:135-138.
4You Y, Fuchs E F, Lin D, Barnes P R. Reactive power demand of transformers with DC bias[J]. IEEE, Industry Applications Magazine, 1996, 2 Issue. (4):45-52.
5Takada S, Mohri K, Takito H, et al. Magnetic losses of electrical iron sheet in squirrel-cage induction motor driven by PWM inverter[J]. IEEE Transactions on Magnetics, 1997, 33(5) : 3760-3762.
