C. H. Han, G. S. Jang, H. S. Lee, 2019, MVDC (Medium-Voltage Direct Current) technology trends, KIEE Mag., Vol. 68, No. 1, pp. 17-21

Y. Zhao, P. Crossley, 2020, Impact of DC bias on differential protection of converter transformers, Int. J. Electr. Power Energy Syst., Vol. 115, pp. 1-10

J. S. Song, C. H. Kim, 2025, A Study on the Impact of AC Transformer due to Shared AC/DC Neutral Line, pp. 1072-1076

2021, IEEE Guide for the Synchron ous Monitoring of Direct Current (DC) Bias Magnetic Current Distribution in Power Grid

H. Hamzehbahmani, H. Griffiths, A. Haddad, D. Guo, 2015, Earthing requirements for HVDC systems, pp. 1-7

X. Han, W. Sima, M. Yang, L. Li, T. Yuan, Y. Si, 2018, Transient characteristics under ground and short-circuit faults in a ±500 kV MMC-based HVDC system with hybrid DC circuit breakers, IEEE Trans. Power Del., Vol. 33, No. 3, pp. 1378-1387

R. Li, L. Xu, 2018, Review of DC fault protection for HVDC grids, Wiley Interdiscip. Rev. Energy Environ., Vol. 7, No. 2

L. Bolduc, A. Gaudreau, A. Dutil, 2000, Saturation tim e of transformers under dc excitation, Electr. Power Syst. Res., Vol. 56, No. 2, pp. 95-102

F. Wu, S. Yu, Z. Zhao, W. Quan, 2019, Calculation an d control of DC bias current distribution in an AC power system around a typical ±800 kV DC grounding electrode, J. Eng., Vol. 2019, No. 16, pp. 3145-3149

Z. Wang, 2018, Novel DC bias suppression device based on adjustable parallel resistances, IEEE Trans. Power Del., Vol. 33, No. 4, pp. 1787-1797

S. Ma, 2021, A novel DC bias suppression method considering the cooperation of multiple devices, IEEE Access, Vol. 9, pp. 130212-130220

J. S. Song, G. J. Cho, J. S. Kim, J. Y. Shin, D. H. Kim, C. H. Kim, 2018, A study on the optimal setting method of directional overcurrent relay considering fault ride through of distributed generation, The Transactions of the Korean Institute of Electrical Engineers, Vol. 67, No. 8, pp. 1002-1008