TY - JOUR

T1 - Series expansions for line series impedances considering different specific resistances, magnetic permeabilities, and dielectric permittivities of conductors, air, and ground

AU - Hofmann, L.

PY - 2003/4/1

Y1 - 2003/4/1

N2 - A power series and for very high frequencies, an asymptotic series expansion for the calculation of the self and mutual line impedances are derived and verified. The different specific resistances, magnetic permeabilities, and dielectric permittivities of the three relevant materials, namely, conductor, air, and ground, are completely taken into account, which is not completely considered in the available literature. Breaking up the power series after the first terms results in simplified expressions near power frequency. The defining equations for the coefficients of the power series expansion are given by infinite series expansions. Their limiting values, as well as the frequency curves of the self and mutual resistances and inductances, are calculated for different magnetic ground permeabilities. Due to the current displacement in the lossy ground, the resistances increase with frequency whereas the inductances decrease. With increasing permeability of the ground, the resistances and inductances increase due to the higher magnetic flux in the ground.

AB - A power series and for very high frequencies, an asymptotic series expansion for the calculation of the self and mutual line impedances are derived and verified. The different specific resistances, magnetic permeabilities, and dielectric permittivities of the three relevant materials, namely, conductor, air, and ground, are completely taken into account, which is not completely considered in the available literature. Breaking up the power series after the first terms results in simplified expressions near power frequency. The defining equations for the coefficients of the power series expansion are given by infinite series expansions. Their limiting values, as well as the frequency curves of the self and mutual resistances and inductances, are calculated for different magnetic ground permeabilities. Due to the current displacement in the lossy ground, the resistances increase with frequency whereas the inductances decrease. With increasing permeability of the ground, the resistances and inductances increase due to the higher magnetic flux in the ground.

KW - electric impedance

KW - electric resistance

KW - magnetic permeability

KW - permittivity

KW - air

KW - overhead line conductors

KW - inductance

KW - magnetic flux

KW - line series impedances

KW - series expansions

KW - specific resistances

KW - magnetic permeabilities

KW - dielectric permittivities

KW - conductors

KW - ground

KW - asymptotic series expansion

KW - mutual line impedances

KW - self line impedances

KW - power series

KW - infinite series expansions

KW - limiting values

KW - frequency curves

KW - inductances

KW - magnetic ground permeabilities

KW - current displacement

KW - lossy ground

KW - Impedance

KW - Permeability

KW - Permittivity

KW - Conductors

KW - Frequency

KW - Conducting materials

KW - Magnetic materials

KW - Magnetic flux

KW - Dielectric materials

KW - Equations

U2 - 10.1109/TPWRD.2003.810493

DO - 10.1109/TPWRD.2003.810493

M3 - Article

VL - 18

SP - 564

EP - 570

JO - IEEE Transactions on Power Delivery

JF - IEEE Transactions on Power Delivery

SN - 1937-4208

IS - 2

ER -