scholarly journals PULSED FIELD SKIN EFFECT CALCULATIONS FOR CYLINDRICAL CONDUCTORS

1966 ◽  
Author(s):  
D Baker ◽  
M MacRoberts ◽  
L Mann
Keyword(s):  
Skin Effect ◽  
Pulsed Field ◽  
Cylindrical Conductors

Enhanced method for pulse skin effect calculation of cylindrical conductors

2020 ◽  
Vol 39 (3) ◽  
pp. 623-635
Author(s):  
Nebojsa B. Raicevic ◽  
Slavoljub R. Aleksic ◽  
Ilona Iatcheva ◽  
Marinko Barukcic
Keyword(s):  
Electromagnetic Field ◽  
Density Distribution ◽  
Cross Section ◽  
Current Density ◽  
Skin Effect ◽  
Current Density Distribution ◽  
Accurate Solution ◽  
Lightning Strike ◽  
Content Type ◽  
Cylindrical Conductors

Purpose This paper aims to present a new approach to the numerical solution of skin effect integral equations in cylindrical conductors. An approximate, but very simple and accurate method for calculating the current density distribution, skin-effect resistance and inductance, in pulse regime of cylindrical conductor, having a circular or rectangular cross-section, is considered. The differential evolution method is applied for minimization of error functional. Because of its application in the practice, the lightning impulse is observed. Direct and inverse fast Fourier transform is applied. Design/methodology/approach This method contributes to increasing of correctness and much faster convergence. As the electromagnetic field components depend on the current density derivation, the proposed method gives a very accurate solution not only for current density distribution and resistance but also for field components and for internal inductance coefficients. Distribution of current and electromagnetic field in bus-bars can be successfully determined if the proximity effect is included together with the skin effect in calculations. Findings The study shows the strong influence of direct lightning strikes on the distribution of electrical current in cables used in lightning protection systems. The current impulse causes an increase in the current density at all points of the cross-section of the conductor, and in particular the skin effect on the external periphery. Based on the data calculated by using the proposed method, it is possible to calculate the minimum dimensions of the conductors to prevent system failures. Research limitations/implications There are a number of approximations of lightning strike impulse in the literature. This is a limiting factor that affects the reliability and agreement between measured data with calculated values. Originality/value In contrast with other methods, the current density function is approximated by finite functional series, which automatically satisfy wave equation and existing boundary conditions. It is necessary to minimize the functional. This approach leads to a very accurate solution, even in the case when only two terms in current approximation are adopted.

Iterative formulation for the skin effect on cylindrical conductors based on the Feynman's approach

2019 ◽  
Vol 33 (1) ◽  
Author(s):  
Jose Roberto Cardoso ◽  
Mauricio Barbosa Camargo Salles ◽  
Ronaldo F. Pereira ◽  
Eduardo C. Costa ◽  
Alfeu J. Sguarezi Filho
Keyword(s):  
Skin Effect ◽  
Cylindrical Conductors

scholarly journals Skin effect in rectangular conductors at high frequencies

1929 ◽  
Vol 122 (790) ◽  
pp. 533-542 ◽  
Keyword(s):  
High Frequency ◽  
Skin Effect ◽  
General Nature ◽  
Rectangular Section ◽  
Electrical Force ◽  
High Frequencies ◽  
One Dimensional ◽  
Finite Breadth ◽  
Parallel Strips ◽  
Cylindrical Conductors

There is at present little exact information either theoretical or experimental on the high frequency resistance of cylindrical conductors of rectangular section, although the general nature of the phenomenon is quite well known and has been exhaustively treated in the case of circular conductors by Kelvin, Heaviside, Russell and others. The first method of attack on the problem of the rectangular conductor is to treat it as a strip of infinite breadth when the problem becomes one dimensional and requires simply a solution of ∂ 2 E/∂ x 2 = 4πμ/ρ ∂E/∂ t E being the electrical force and μ and ρ the permeability and resistivity respectively. The solution of the problem for two parallel strips was first given by Rayleigh and it was shown that for high frequencies the current decreases exponentially toward the centre of the conductor, being confined effectively to a surface layer so that the resistance of the conductor was the same as if composed of surface strips of thickness (2πμω/ρ) -½ , ω to being the periodicity. This approximation, however, gives much too low values for the high frequency resistance of a conductor of finite breadth.

TREATMENT OF WELDED JOINTS BY A PULSE ELECTROMAGNETIC FIELD WITH SMALL SKIN-EFFECT

2018 ◽  
Vol 2018 (50) ◽  
pp. 106-114
Author(s):  
Yu. Vasetskiy ◽  
◽  
I. Kondratenko ◽  
I. Mazurenko ◽  
М. Pashchyn ◽  
...  
Keyword(s):  
Electromagnetic Field ◽  
Welded Joints ◽  
Skin Effect ◽  
Pulse Electromagnetic Field

Controlling Gas Selectivity in Molecular Porous Liquids by Tuning the Cage Window Size

2019 ◽  
Author(s):  
Benjamin Egleston ◽  
Konstantin V. Luzyanin ◽  
Michael C. Brand ◽  
Rob Clowes ◽  
Michael E. Briggs ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Chemical Synthesis ◽  
Field Gradient ◽  
Window Size ◽  
Standard Approach ◽  
Porous Solids ◽  
Pulsed Field Gradient Nmr ◽  
Pulsed Field ◽  
Cage Molecules ◽  
Gas Selectivity

Control of pore window size is the standard approach for tuning gas selectivity in porous solids. Here, we present the first example where this is translated into a molecular porous liquid formed from organic cage molecules. Reduction of the cage window size by chemical synthesis switches the selectivity from Xe-selective to CH<sub>4</sub>-selective, which is understood using <sup>129</sup>Xe, <sup>1</sup>H, and pulsed-field gradient NMR spectroscopy.

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