Earthing requirements for HVDC systems

Following the recent developments in the field of power electronic valves, High Voltage Direct Current (HVDC) systems have become more attractive in power systems, and are widely recognised as a suitable tool for future power systems, especially in bulk power transmission over long distances. Grounding electrodes are an important part with significant roles in the operation of the HVDC systems. In this paper, first a brief review of different types of HVDC configuration is presented. Essential requirements in the design and operation of the HVDC grounding system are then presented and discussed. In the relevant studies, environmental impacts of HVDC electrodes, e.g. step voltage, effect on the buried metallic structures, DC magnetic bias of power transformers and mitigation methods are highlighted. Finally, a basic modelling of different physical configurations of HVDC electrode resistance is performed.

[1]  Christian M. Franck,et al.  Comparison of fault currents in multiterminal HVDC grids with different grounding schemes , 2014, 2014 IEEE PES General Meeting | Conference & Exposition.

[2]  Wan Da,et al.  Application of bias-resisting reverse DC injection at neutral point of transformers , 2005 .

[3]  J. Zou,et al.  Analysis of the toroidal HVDC grounding systems in horizontal multilayer soils , 2006, IEEE Transactions on Magnetics.

[4]  W. Ruan,et al.  Design Considerations of HVDC Grounding Electrodes , 2005, 2005 IEEE/PES Transmission & Distribution Conference & Exposition: Asia and Pacific.

[5]  Sheng Wang,et al.  Influence of HVDC ground electrode current on AC transmission system and development of restraining device , 2008, 2008 Third International Conference on Electric Utility Deregulation and Restructuring and Power Technologies.

[6]  Hanna Carlsson,et al.  Environmental and Geographical Aspects in HVDC Electrode Design , 1996, IEEE Power Engineering Review.

[7]  T G Magg,et al.  Caprivi Link HVDC Interconnector: Site selection, geophysical investigations, interference impacts and design of the earth electrodes , 2010 .

[8]  Yu Jiang,et al.  Research on the Fault Location Principle for the Earthing Electrode Line of the UHVDC Transmission System , 2013 .

[9]  Xu Guanghu,et al.  The basic law and influencing factor of DC bias distribution in AC power which is near the grounding electrode of 800kV HVDC , 2014, 2014 International Conference on Power System Technology.

[10]  M. Rossi,et al.  Technical and compatibility issues in the design of HVDC sea electrodes , 2012, International Symposium on Electromagnetic Compatibility - EMC EUROPE.

[11]  M. Sublich,et al.  Alternatives for blocking direct current in AC system neutrals at the Radisson/LG2 complex , 1992 .

[12]  Rong Zeng,et al.  Numerical analysis of potential distribution between ground electrodes of HVDC system considering the effect of deep earth layers , 2008 .

[13]  H. Thunehed,et al.  Geophysical and geological pre-investigations for HVDC-electrodes , 2007, 2007 IEEE Power Engineering Society Conference and Exposition in Africa - PowerAfrica.

[14]  Peter Kulchyski.  and , 2015 .

[15]  F. Schettler,et al.  Technical Guidelines and Prestandardization Work for First HVDC Grids , 2014, IEEE Transactions on Power Delivery.

[16]  Jian Zhang,et al.  Study of the influence of dc currents in the ground on transformers and its suppression methods , 2006 .

[17]  M.P. Bahrman,et al.  The ABCs of HVDC transmission technologies , 2007, IEEE Power and Energy Magazine.