scholarly journals THE DISTRIBUTION OF MAGNETIC AND THERMAL FIELDS, POWER LOSSES IN ELECTROMAGNETIC SHIELD OF UNDERGROUND TWO-CIRCUIT CABLE LINE

2021 ◽  
Vol 2021 (60) ◽  
pp. 12-21
Author(s):  
I.M. Kucheriava ◽  
Keyword(s):  
Maximum Temperature ◽  
Power Cable ◽  
Cable Line ◽  
Thermal Fields ◽  
Operating Current ◽  
Electromagnetic Shield ◽  
Electromagnetic Characteristics ◽  
Extra High Voltage ◽  
The Magnetic Field ◽  
Lower Heating

In the article, the magnetic and thermal field distributions generated by underground two-circuit extra-high voltage power cable line in the environment, particularly near the cables and flat aluminum shield, which is located at a different distance from the cables and has different thicknesses, are analyzed. The unique features of the magnetic field and temperature distributions inside the shield are computed and studied. For the cases under consideration, the Joule losses in the external shield do not exceed 3% of the losses in the cables. The primary electromagnetic characteristics are compared for the aluminum shield (shielding efficiency is 1,94) and the shield with lower conductivity (shielding efficiency is equal to 1,2). As shown, the thicker shield helps to increase the ampacity of the cable line owing to lower heating. The actual operating current of the cable line under consideration depends on the distance of the shield from the cables owing to the relation between their maximum temperature and this distance. Ref. 15, fig. 7, table.

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

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.

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

2012 ◽  
Vol 2 (2) ◽  
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.

Feasibility of a 5 T Magnet by using Bi-2223/Ag Tape at 30 K

1999 ◽  
Vol 13 (09n10) ◽  
pp. 1345-1350 ◽  
Author(s):  
A. Matrone ◽  
M. Ariante ◽  
V. Cavaliere ◽  
M. Mariani ◽  
G. Masullo ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Cross Section ◽  
Fill Factor ◽  
Concept Design ◽  
Operating Current ◽  
Preliminary Computation ◽  
The Magnetic Field

The feasibility of a 5 T magnet by using Bi-2223/Ag tapes at 30 K has been investigated. Preliminary computation demonstrates that the target is attainable by assembling 20 double pancakes manufactured by co-winding two Bi-2223/Ag tapes having overall cross-section of 0.25 × 3.5 mm 2 and 25% fill factor, being the expected operating current about 200 A. The pancakes located at the edges are the most critical because the component of the magnetic field orthogonal to the tape surface is large enough to strongly depress J c . To overcome this problem the edge pancakes could be fabricated by using Bi-2223/Ag tapes with new concept design (e.g. with oriented filaments).

scholarly journals Simulation Analysis of Current in Metal Sheath of Power Cable Considering Temperature Characteristics

2021 ◽  
Vol 2108 (1) ◽  
pp. 012015
Author(s):  
Jian Fang ◽  
Min Zhang ◽  
Wenxiong Mo ◽  
Bo Huang ◽  
Jiaxing He ◽  
...  
Keyword(s):  
Simulation Analysis ◽  
Equivalent Circuit Model ◽  
Circuit Model ◽  
Temperature Data ◽  
Power Cable ◽  
Temperature Characteristics ◽  
Vector Fitting ◽  
Fitting Method ◽  
Operating Current ◽  
Metal Sheath

Abstract This paper proposes a cable broadband circuit model considering the temperature characteristics. This paper establishes the equivalent circuit model of the cross-bonded power cable and proposes the broadband parameter calculation method considering the temperature. The cable parameters are calculated by the vector fitting method. Based on the operating current and cable temperature data of the cable on a certain day, the simulation analysis of the cable sheath current considering the temperature is carried out using Simulink. Finally, the simulation results show that the cable sheath current is significantly affected by temperature.

scholarly journals THE MAGNETIC FIELD OF UNDERGROUND 330 KV CABLE LINE AND WAYS FOR ITS REDUCTION

2019 ◽  
Vol 2019 (5) ◽  
pp. 3-9 ◽  
Author(s):  
A.A. Shcherba ◽  
◽  
A.D. Podoltsev ◽  
I.M. Kucheriava ◽  
◽  
...  
Keyword(s):  
Magnetic Field ◽  
Cable Line ◽  
The Magnetic Field

scholarly journals Thermal Effect of Single Loop Shield on High-Voltage Cable Line Capacity

2021 ◽  
Author(s):  
Oleksandr Tkachenko ◽  
◽  
Vladimir Grinchenko ◽  
Pavel Dobrodeyev ◽  
◽  
...  
Keyword(s):  
Thermal Effect ◽  
High Voltage ◽  
Thermal Field ◽  
Magnetic Coupling ◽  
Maximum Temperature ◽  
Thermal Resistivity ◽  
Power Cables ◽  
Cable Line ◽  
Single Loop ◽  
Short Section

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.

scholarly journals A Multi-Scale Analysis of the Fire Problems in an Urban Utility Tunnel

Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1976 ◽  
Author(s):  
Kai Ye ◽  
Xiaodong Zhou ◽  
Lizhong Yang ◽  
Xiao Tang ◽  
Yuan Zheng ◽  
...  
Keyword(s):  
Temperature Fields ◽  
Maximum Temperature ◽  
Power Cable ◽  
Relative Width ◽  
Gas Temperature ◽  
Safety Level ◽  
The Sustainable Development ◽  
Fuel Burning ◽  
Important Solution ◽  
Utility Tunnel

Building utility tunnels has been widely adopted as an important solution for the sustainable development of cities, but their unique fire problems have not attracted enough attention to date. With the purpose of preliminarily understanding the fire phenomena in a utility tunnel, this study performed a comprehensive analysis, including the burning behaviour of accommodated cables, hot gas temperature field and enhanced fuel burning rates based on bench-scale, full-scale and model-scale fire tests. The critical exposed radiative heat flux for the 10-kV power cable to achieve complete burning was identified. The whole burning process was divided into five phases. The cable’s noteworthy hazards and dangerous fire behaviours were also examined. The two-dimensional (2D) gas temperature fields and longitudinal maximum temperature distributions were investigated carefully, after which a versatile model was derived. The model predicted the maximum temperature attenuation of both upstream and downstream flows reasonably well. Finally, the phenomenon of enhanced fuel burning was explored. A multivariate cubic function that considers the global effects of relative width, height and distance was further proposed to estimate the enhancement coefficient. The current findings can provide designers and operators with valuable guidance for the integrated promotion of utility tunnels’ fire safety level.

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