# power_cableparam

Compute RLC parameters of radial copper cables with single screen, based on conductor and insulator characteristics

## Syntax

power_cableparam
[r,l,c,z] = power_cableparam(CableData)

## Description

power_cableparam opens the Cable Parameters Tool with the default cable parameter values provided by Simscape™ Electrical™ Specialized Power Systems software.

[r,l,c,z] = power_cableparam(CableData) computes the impedances and capacitances of a structure, CableData, that represents a set of cables that have a screen conductor.

## Input Arguments

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Conductor and insulator characteristics for a set of cables that have a screen conductor, specified as a structure with the following fields:

Field

Description

N

the number of cables

f

the frequency in hertz to be used to evaluate RLC parameters

rh0_e

the ground resistivity (in ohm.meters)

n_ba

the number of strands contained in one phase conductor

d_ba

diameter of one strand (in m)

rho_ba

DC resistivity of conductor in ohms*m.

mu_r_ba

relative permeability of the conductor material.

D_a

phase conductor outside diameter (in m)

rho_x

DC resistivity of the screen conductor in ohms*m.

S_x

Total section of screen conductor (in m^2)

d_x

screen conductor internal diameter (in m)

D_x

screen conductor external diameter (in m)

GMD_phi

Geometric Mean Distance between the cables.

d_iax

phase-screen insulator internal diameter (in m)

D_iax

phase-screen insulator external diameter (in m)

epsilon_iax

relative permittivity of the phase-screen insulator material.

d_ixe

outer screen insulator internal diameter (in m)

D_ixe

outer screen insulator external diameter (in m)

epsilon_ixe

relative permittivity of the outer screen insulator material.

## Output Arguments

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Parameters of the radial copper cables, returned as a structure with the following fields:

Variable, Field

Description

r.aa

Self resistance of phase conductor, in Ohm/Km

r.xx

Self resistance of screen conductor, in Ohm/Km

r.ab

Mutual resistance between the phase conductors, in Ohm/Km

r.ax

Mutual resistance between phase and screen conductors, in Ohm/Km

l.aa

Self inductance of phase conductor, in Henries/Km

l.xx

Self inductance of screen conductor, in Henries/Km

l.ab

Mutual inductance between the phase conductors, in Henries/Km

l.ax

Mutual inductance between phase and screen conductor, in Henries/Km

c.ax

Capacitance between the phase conductor and its screen conductor, in Farad/Km

c.xe

Capacitance between the screen conductor and the ground, in Farad/Km

z.aa

Self impedance of phase conductor, in Ohm/Km

z.xx

Self impedance of screen conductor, in Ohm/Km

z.ab

Mutual impedance between phase conductors, in Ohm/Km

z.ax

Mutual impedance between phase and corresponding screen conductors, in Ohm/Km

### Building the RLC Matrices

These computed resistances, impedances, and capacitances need to be organized into 2N-by-2N matrices that can be directly used in the block you selected to model your cable. See the 4 Cables with screen (PI model) block in the power_cable example.

The RLC matrices are defined as follows (the example is given for a 3-cable configuration):

$\begin{array}{cc}R=\left[\begin{array}{cccccc}{r}_{aa}& {r}_{ax}& {r}_{ab}& {r}_{ab}& {r}_{ab}& {r}_{ab}\\ {r}_{ax}& {r}_{xx}& {r}_{ab}& {r}_{ab}& {r}_{ab}& {r}_{ab}\\ {r}_{ab}& {r}_{ab}& {r}_{aa}& {r}_{ax}& {r}_{ab}& {r}_{ab}\\ {r}_{ab}& {r}_{ab}& {r}_{ax}& {r}_{xx}& {r}_{ab}& {r}_{ab}\\ {r}_{ab}& {r}_{ab}& {r}_{ab}& {r}_{ab}& {r}_{aa}& {r}_{ax}\\ {r}_{ab}& {r}_{ab}& {r}_{ab}& {r}_{ab}& {r}_{ax}& {r}_{xx}\end{array}\right]& L=\left[\begin{array}{cccccc}{l}_{aa}& {l}_{ax}& {l}_{ab}& {l}_{ab}& {l}_{ab}& {l}_{ab}\\ {l}_{ax}& {l}_{xx}& {l}_{ab}& {l}_{ab}& {l}_{ab}& {l}_{ab}\\ {l}_{ab}& {l}_{ab}& {l}_{aa}& {l}_{ax}& {l}_{ab}& {l}_{ab}\\ {l}_{ab}& {l}_{ab}& {l}_{ax}& {l}_{xx}& {l}_{ab}& {l}_{ab}\\ {l}_{ab}& {l}_{ab}& {l}_{ab}& {l}_{ab}& {l}_{aa}& {l}_{ax}\\ {l}_{ab}& {l}_{ab}& {l}_{ab}& {l}_{ab}& {l}_{ax}& {l}_{xx}\end{array}\right]\end{array}$

$C=\left[\begin{array}{cccccc}{c}_{ax}& -{c}_{ax}& 0& 0& 0& 0\\ -{c}_{ax}& {c}_{ax}+{c}_{xe}& 0& 0& 0& 0\\ 0& 0& {c}_{ax}& -{c}_{ax}& 0& 0\\ 0& 0& -{c}_{ax}& {c}_{ax}+{c}_{xe}& 0& 0\\ 0& 0& 0& 0& {c}_{ax}& -{c}_{ax}\\ 0& 0& 0& 0& -{c}_{ax}& {c}_{ax}+{c}_{xe}\end{array}\right]$

## Examples

For an example using the power_cableparam function, see the power_cable model.