air gaps; power cables; cable shielding; finite element analysis; contact resistance; electrical contacts
Abstract :
[en] The shielding of buried three-phase high-voltage power lines can be done by placing them in conducting ferromagnetic U-shaped gutters covered with plates. In case of a perfect electrical contact between adjacent gutters and between adjacent cover plates, induced currents in the shield efficiently reduce the magnetic field generated by the cables. As however a perfect contact cannot be guaranteed, in practice, it is useful to quantify the effect of a defective electrical contact on the field reduction. From two-dimensional/three-dimensional finite element computations and experiments, the influence of the contact resistance on the shielding efficiency is investigated, as a function of the ratio of axial length to height of the shield elements. Furthermore, the effect of other parameters on the shielding efficiency is studied: the ratio of axial length to height, a parasitic air gap between the gutter and the cover plate and the type of the shield material. It was found that a low contact resistance deteriorates much more the shielding in case of an aluminium shield than in case of a steel shield. As expected, the effect is larger for shield elements with relatively short axial length with regard to the other dimensions. Nevertheless, the effect remains quite significant for aluminium shields with practically convenient dimensions.
Disciplines :
Electrical & electronics engineering
Author, co-author :
Koroglu, S.
Sergeant, P.
V Sabariego, Ruth ; Université de Liège - ULiège > Dép. d'électric., électron. et informat. (Inst.Montefiore) > Applied and Computational Electromagnetics (ACE)
Dang, Quoc Vuong ; Université de Liège - ULiège > Dép. d'électric., électron. et informat. (Inst.Montefiore) > Applied and Computational Electromagnetics (ACE)
De Wulf, M.
Language :
English
Title :
Influence of contact resistance on shielding efficiency of shielding gutters for high-voltage cables
Hartal, O., Merzer, M., and Netzer, M.: 'Shielding from ELF magnetic fields emanating from power plants in large facilities', Environmentalist, 2005, 25, (2-4), p. 209-21410.1007/s10669-005-4285-7
Koroglu, S., Adam, A.A., Umurkan, N., and Gulez, K.: 'Leakage magnetic flux density in the vicinity of induction motor during operation', Electr. Eng. (Archiv fur Elektrotechnik), 2009, 91, (1), p. 15-2110.1007/s00202-009-0111-4
Sergeant, P., Sabariego, R.V., Crevecoeur, G.L., Sergeant, P., and Geuzaine, C.: 'Analysis of perforated magnetic shields for electric power applications', IET Electr. Power Appl., 2009, 3, (2), p. 123-13210.1049/iet-epa:20080203
Sergeant, P., Dupré, L., and Melkebeek, J.: 'Active and passive magnetic shielding for stray field reduction of an induction heater with axial flux', IEE Proc. Electr. Power Appl., 2005, 152, (5), p. 1359-136410.1049/ip-epa:20050005 1350-2352
Zucca, M., Lorusso, G., Fiorillo, F., Roccato, P.E., and Annibale, M.: 'Highly efficient shielding of high-voltage underground power lines by pure iron screens', J. Magn. Magn. Mater., 2008, 320, p. 1065-106910.1016/j.jmmm.2008.04.096 0304-8853
Cardelli, E., Faba, A., and Pirani, A.: 'Nonferromagnetic open shields at industrial frequency rate', IEEE Trans. Magn., 2010, 46, (3), p. 889-89810.1109/TMAG.2009.2031110 0018-9464
Sergeant, P., Dupré, L., and Melkebeek, J.: 'Magnetic shielding of buried high voltage cables by conductive metal plates', COMPEL, 2008, 27, (1), p. 170-18010.1108/03321640810836735
De Wulf, M., Wouters, P., and Sergeant, P.: et al. 'Electromagnetic shielding of high-voltage cables', J. Magn. Magn. Mater., 2007, 316, p. 908-91110.1016/j.jmmm.2007.03.137 0304-8853
Dular, P., Kuo-Peng, P., Geuzaine, C., Sadowski, N., and Bastos, J.P.A.: 'Dual magneto-dynamic formulations and their source fields associated with massive and stranded inductors', IEEE Trans. Magn., 2000, 36, (4), p. 3078-30810018-9464