6BozokiB., ChanoS R., DvorakL. L., et al. The Effects of GIC on Protective Relaying [J ]. IEEE Transactions on Power Delivery. 1996, 11 (2): 725 -739.
7Biro O, Buchgraber G, Leber G, et al. Prediction of magnetizing current waveforms in a three -phase power transformer under DC bias [ J] . IEEE Transactions on Magnetics, 2008, 44 ( 6 ) : 1554 -1557.