Positive sequence impedance

These equations are based on the Cigré Guide 531 for symmetric systems without earth return path.

For submarine armoured three-core cables, the three screens are assumed to be solidly bonded to the armour at least at both ends.

Symbol
$Z_{pos}$
Unit
$\Omega$/m
Formulae
$R_{c} + 1.0 i X_{c}$single point or cross-bonding
$R_{c} + 1.0 i X_{c} + \frac{X_{s}^{2}}{R_{s} + 1.0 i X_{s}}$bonded at both sides
$R_{c} \left(\lambda_{2} + 1\right) + 1.0 i X_{c} + \frac{X_{s}^{2}}{R_{s} + 1.0 i X_{s}}$armoured three-core cables bonded at both sides
Related
$\lambda_{2}$
$R_{c}$
$X_{c}$