Self reactance of screen/sheath

Definition equivalent mutual reactance is according to IEEE 575-2014 chapter E.1.4.3.1. (without) and Cigré guide 531 chapter 4.2.3.8 (with earth return).

Symbol

$X_s$

Unit

$\Omega$/m

Formulae

$\omega \frac{\mu_0}{2\pi} \ln\left(\frac{1}{r_s}\right)$	without earth return
$\omega \frac{\mu_0}{2\pi} \ln\left(\frac{D_E}{r_s}\right)$	with earth return

Related

$D_E$

Equivalent depth of earth return path [m]

$\mu_0$

Vacuum permeability [H/m]

$\omega$

Angular frequency [rad/s]

$\pi$

Archimedes' constant $\pi$

$r_s$

Mean radius of shield [m]

Used in

$RF$

Reduction factor

$Z_m$

Mutual impedance between phase conductor and metal screen with earth return [$\Omega$/m]

$Z_s$

Self impedance of metal screen with earth return [$\Omega$/m]