Magnetic Concentrators for Reducing the Magnetic Field around Power Cable Line

2019 ◽  
Author(s):  
Mikhail V. Doronin ◽  
George V. Greshnyakov
Keyword(s):  
Magnetic Field ◽  
Power Cable ◽  
Cable Line ◽  
The Magnetic Field

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.

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.

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 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 Evaluation of the magnetic field generated by a power cable in proximity of a joint bay: Comparison between two different approaches

2021 ◽  
Vol 34 (4) ◽  
pp. 511-524
Author(s):  
Giovanni Lucca
Keyword(s):  
Magnetic Field ◽  
Density Field ◽  
Magnetic Flux Density ◽  
Power Cable ◽  
National Authority ◽  
Frequency Magnetic Field ◽  
Power Frequency ◽  
Underground Power Cable ◽  
Actual Geometry ◽  
The Magnetic Field

The paper presents two different approaches for the evaluation of the magnetic flux density field produced by an underground power cable in proximity of areas where joint bays are present; as known, in those areas the field levels are generally much higher compared to the ones generated along the ordinary route. The first and more rigorous 3D approach takes into account the actual geometry of the power cable conductors in the joint bay, while the second one is based on a simplified 2D approach. The main result of the comparison is that the 2D approach, even at short lateral distances from the cable overestimates the field; therefore, one could adopt this method in order to rapidly and conservatively evaluate the distance of compliance (established by each specific national authority) from the cable in order to ensure protection of population from exposure to power frequency magnetic field.

scholarly journals PARTICULARITIES OF MAGNETIC FIELD SHIELDING FOR UNDERGROUND CABLE LINE BY COMPOSITE FILL-UP SOIL WITH MAGNETIC PROPERTIES

2021 ◽  
Vol 2021 (58) ◽  
pp. 14-22
Author(s):  
I.M. Kucheriava ◽  
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Three Dimensional ◽  
3D Models ◽  
Power Cable ◽  
Appreciable Effect ◽  
Cable Line ◽  
Small Height ◽  
Underground Power Cable ◽  
Cable Lines

The computations of the magnetic field generated by high-voltage (330 kV) underground power cable line with special fill-up soil having different dimensions (bulk) are carried out by the two- and three-dimensional computer models. The supplementary soil above the cables is the composite material with effective magnetic properties and serves as a magnetic shield. The computer results obtained by 2D and 3D models are compared. The efficiency of magnetic field shielding depending on the magnetic permeability, width, and height of the fill-up soil is studied. As revealed, there is the optimal small soil height for the best magnetic field mitigation on the top of the ground directly over the cable line. In addition, the width of the magnetic soil has an appreciable effect on shielding efficiency. The shielding of underground single-circuit three-phase power cable lines is efficient only when using the magnetic fill-up soil (or ordinary external screen made of magnetic materials) with enough small height. References 14, figures 7.

Observing the galactic magnetic field

1967 ◽  
Vol 31 ◽  
pp. 375-380
Author(s):  
H. C. van de Hulst
Keyword(s):  
Magnetic Field ◽  
Fair Agreement ◽  
Solar Neighbourhood ◽  
Galactic Magnetic Field ◽  
The Magnetic Field

Various methods of observing the galactic magnetic field are reviewed, and their results summarized. There is fair agreement about the direction of the magnetic field in the solar neighbourhood:l= 50° to 80°; the strength of the field in the disk is of the order of 10-5gauss.

Evolution of Large-Scale Coronal Structures

1994 ◽  
Vol 144 ◽  
pp. 29-33
Author(s):  
P. Ambrož
Keyword(s):  
Magnetic Field ◽  
Field Line ◽  
Large Scale ◽  
Coronal Magnetic Field ◽  
Source Surface ◽  
Solar Cycles ◽  
Characteristic Relationship ◽  
The Magnetic Field ◽  
Coronal Structures

AbstractThe large-scale coronal structures observed during the sporadically visible solar eclipses were compared with the numerically extrapolated field-line structures of coronal magnetic field. A characteristic relationship between the observed structures of coronal plasma and the magnetic field line configurations was determined. The long-term evolution of large scale coronal structures inferred from photospheric magnetic observations in the course of 11- and 22-year solar cycles is described.Some known parameters, such as the source surface radius, or coronal rotation rate are discussed and actually interpreted. A relation between the large-scale photospheric magnetic field evolution and the coronal structure rearrangement is demonstrated.

Emergence of Twisted Magnetic Flux Related Sigmoidal Brightening

2000 ◽  
Vol 179 ◽  
pp. 263-264
Author(s):  
K. Sundara Raman ◽  
K. B. Ramesh ◽  
R. Selvendran ◽  
P. S. M. Aleem ◽  
K. M. Hiremath
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Magnetic Flux ◽  
Ultra Violet ◽  
Active Regions ◽  
Morphological Properties ◽  
Energy Storage And Conversion ◽  
The Sun ◽  
X Rays ◽  
The Magnetic Field

Extended AbstractWe have examined the morphological properties of a sigmoid associated with an SXR (soft X-ray) flare. The sigmoid is cospatial with the EUV (extreme ultra violet) images and in the optical part lies along an S-shaped Hαfilament. The photoheliogram shows flux emergence within an existingδtype sunspot which has caused the rotation of the umbrae giving rise to the sigmoidal brightening.It is now widely accepted that flares derive their energy from the magnetic fields of the active regions and coronal levels are considered to be the flare sites. But still a satisfactory understanding of the flare processes has not been achieved because of the difficulties encountered to predict and estimate the probability of flare eruptions. The convection flows and vortices below the photosphere transport and concentrate magnetic field, which subsequently appear as active regions in the photosphere (Rust & Kumar 1994 and the references therein). Successive emergence of magnetic flux, twist the field, creating flare productive magnetic shear and has been studied by many authors (Sundara Ramanet al.1998 and the references therein). Hence, it is considered that the flare is powered by the energy stored in the twisted magnetic flux tubes (Kurokawa 1996 and the references therein). Rust & Kumar (1996) named the S-shaped bright coronal loops that appear in soft X-rays as ‘Sigmoids’ and concluded that this S-shaped distortion is due to the twist developed in the magnetic field lines. These transient sigmoidal features tell a great deal about unstable coronal magnetic fields, as these regions are more likely to be eruptive (Canfieldet al.1999). As the magnetic fields of the active regions are deep rooted in the Sun, the twist developed in the subphotospheric flux tube penetrates the photosphere and extends in to the corona. Thus, it is essentially favourable for the subphotospheric twist to unwind the twist and transmit it through the photosphere to the corona. Therefore, it becomes essential to make complete observational descriptions of a flare from the magnetic field changes that are taking place in different atmospheric levels of the Sun, to pin down the energy storage and conversion process that trigger the flare phenomena.

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