EFFICIENT SHIELDING OF THREE-PHASE CABLE LINE MAGNETIC FIELD BY PASSIVE LOOP UNDER LIMITED THERMAL EFFECT ON POWER CABLES

The paper deals with a single-loop shield with an asymmetric magnetic coupling used for a magnetic field mitigation of a high-voltage three-phase cable line. The goal is to evaluate a thermal effect of this shield on a cable line capacity. To calculate the flat cable line capacity in the nonshielded case, we use a standard IEC 60287. To achieve the goal we carry out a numerical simulation of the thermal field when the shield is installed. Wherein, we deal with two specific sections. One is a long section with the shield being distant from the cable line. The other is a relatively short section where the shield is located near the power cables. The thermal field is applied for a long section in a two-dimensional formulation, and a three-dimensional formulation is used for the short section. Hence, we have obtained the dependences of the maximum temperature of the power cables on parameters of the shield and its location height above the cable line. The most significant allowable cross-sections of the shield cable and their location height have been determined, when the thermal effect of the shield does not decrease the cable line capacity. These results have ensured the maximum cable line capacity while shielding. The shield temperature is shown to exceed the allowable level in the short section. To reduce it the thermal backfill has been used. We recommend the values of its thermal resistivity to be used for different parameters of the single-loop shield.

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Magnetic field reduction of twisted three-phase power cables of finite length by specific phase mixing

1999 International Symposium on Electromagnetic Compatibility (IEEE Cat. No.99EX147) ◽

10.1109/elmagc.1999.801361 ◽

2003 ◽

Cited By ~ 1

Author(s):

M. Ehrich ◽

L.O. Fichte

Keyword(s):

Magnetic Field ◽

Finite Length ◽

Power Cables ◽

Phase Mixing ◽

Three Phase ◽

Specific Phase

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Innovative calculation methods of the magnetic field from single and double-circuit twisted three-phase cables widely used in MV and LV installations

Open Engineering ◽

10.2478/s13531-011-0058-x ◽

2012 ◽

Vol 2 (2) ◽

Cited By ~ 1

Author(s):

Giovanni Mazzanti ◽

Marco Landini ◽

Effrosyni Kandia ◽

Cesare Biserni ◽

Massimo Marzinotto

Keyword(s):

Magnetic Field ◽

Power Distribution ◽

Approximate Expression ◽

Power Cable ◽

Cable Line ◽

Worst Case ◽

Medium Voltage ◽

Three Phase ◽

Worst Case Approach ◽

The Magnetic Field

AbstractThis paper proposes a simple innovative formula for the calculation of the magnetic field generated by a single and a double circuit twisted three-phase power cable line. The formula results a good approximation of the rigorous analytical one and at the same time is much more accurate than the approximated formula found in literature, as demonstrated by some cases of a twisted three-phase power cable used for power distribution at the medium voltage level. The effectiveness of this simple innovative formula is also examined in the case of a double-circuit twisted three-phase power cable line following the’ worst case’ approach and concluding at proposing an approximate expression for the total magnetic field generated by both twisted three-phase power cables.

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MAGNETIC FIELD SHIELDING OF UNDERGROUND POWER CABLE LINE BY H-SHAPED SHIELD

Tekhnichna Elektrodynamika ◽

10.15407/techned2020.06.015 ◽

2020 ◽

Vol 2020 (6) ◽

pp. 15-20

Author(s):

I.M. Kucheriava ◽

Keyword(s):

Magnetic Field ◽

Low Carbon Steel ◽

Power Cable ◽

Low Carbon ◽

Shielding Effectiveness ◽

Cable Line ◽

Three Phase ◽

Underground Power Cable ◽

Extra High Voltage ◽

The Magnetic Field

In the article the magnetic field distributions, generated by underground extra-high voltage (330 kV) three-phase power cable line in the environment, in particular near the cables in the trench and on the ground, are analyzed for using of H-shaped shield made of different materials including aluminum, low carbon steel and non-oriented grain steel. As shown, the best shielding effectiveness is realized by aluminium shield. The H-shaped shield made of high-conducting non-magnetic materials is proposed to use in order to mitigate the magnetic field level on the ground down to regulated nonhazardous values. References 14, figures 7.

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