Simplified Underground Cable

 Name for Identification

Text

Optional text parameter for identification of the component.

 Cable Number

Choice

Select a number between 1 to 12.  This parameter is used for the numbering of multiple cables in the same right of way.

Cable Layers

Choice

Select the configuration of the cable layers. C and I represent conducting and insulating layer respectively.

Cable Configuration

Choice

Select Single, Three Cables (trefoil), Three Cables (Flat), Three Cables (trefoild-touching), or Two Cables.

Horizontal Translation from Centre

REAL

Literal

Enter the translation of the cable centre-point along the horizontal (x) axis [m]. This value is relative to a local x=0 point, which is derived given the position of all cables in this segment.

Depth Below Ground Surface

REAL

Literal

Enter the depth of the cable centre below the ground plane surface [m].

Distance Between Adjacent Cables

REAL

Literal

Enter the distance between adjacent cables [m].

The parameter is disabled when  Cable Configuration | Three Cables (trefoild-touching) is selected.

Cross-Bonding or Conductor Elimination

Choice

Select Disable, Eliminate Outermost Conducting Layer, Eliminate All Outer Conducting Layers, or Enable Cross-Bonding.

Choose which conducting layers to eliminate (if any), or enable  the ideal cross-bonding feature.

Cross-Bonding Group

Choice

Select the group number to which this cable belongs. See Ideal Cross-Bonding for more details.

NOTE:

Each cable group defines a cross-bonded system of three cables. Each cable in the group should have the same set of cross-bonded conductors.  There can be multiple cross-bonded cable groups or a combination of cross-bonded and non cross-bonded cables (ex. a cable system with three cross-bonded and two non cross-bonded cables). Usually in a cross-bonded cable system, only sheaths are transposed at regular intervals. However (if required), any other conductor can also be be transposed.

In some applications, the inner conductor is transposed other than the sheath to obtain a balanced system. This can be accomplished by enabling cross-bonding/transposition of both inner conductor and sheath. In some practical applications, the sheaths at major section points (must consist of three cable sections) of the cross-bonded cable are connected to the ground. This can be approximated by mathematically eliminating the sheath of the three cables in the group (i.e. conductor layer elimination).

Layer Thickness is Specified As

Choice

Select the manner in which the layer thicknesses are specified. If radial from centre is selected, enter the distance from the centre-point to the outer radius of the layer.

 Conductor Inner Radius

REAL

Literal

Enter the inner radius of the corresponding conductor.  If this is the central solid conductor, enter 0.0 [m]

Conductor Outer Radius

REAL

Literal

Enter the outer radius of the corresponding conductor.

1st Insulating Layer

REAL

Literal

Enter either the outer radius or the thickness of this insulator, depending on the Layer Thickness is Specified As parameter [m].

Sheath

REAL

Literal

Enter either the outer radius or the thickness of the sheath, depending on the Layer Thickness is Specified As parameter [m].

2nd Insulating Layer

REAL

Literal

Enter either the outer radius or the thickness of this insulator, depending on the Layer Thickness is Specified As parameter [m].

Armour

REAL

Literal

Enter either the outer radius or the thickness of the armour, depending on the Layer Thickness is Specified As parameter [m].

3rd Insulating Layer

REAL

Literal

Enter either the outer radius or the thickness of this insulator, depending on the Layer Thickness is Specified As parameter [m].

Conductor/Insulator Property Given As

Choice

For conductors, specify whether to enter the resistivity [Wm] or the DC resistance [W/km] of the corresponding conductor. Also, a number of typical material resistivity values are provided for ease in data entry.

For insulators, specify whether to enter the capacitance [mF/km] or the relative permeability of the corresponding insulator. Also, a number of typical material relative permeability values are provided for ease in data entry.

DC Resistance

REAL

Literal

Enter the conductor DC resistance [W/km].

Resistivity

REAL

Literal

Enter the resistivity of the corresponding conductor [Wm].

Capacitance

REAL

Literal

Enter the capacitance of the insulating layer [mF/km].

Relative Permittivity

REAL

Literal

Enter the relative permittivity of the corresponding insulator.

Temperature Correction of Conductor Resistances

Choice

Select Enable or Disable.

When enabled, operating temperature and coefficients must be provided to adjust conductor resistance.

Reference Temperature

REAL

Literal

Enter the temperature, at which the conductor resistance is defined [°C].

Operating Temperature

REAL

Literal

Enter the actual operating temperature for each conducting layer [°C].

Temperature Coefficient

REAL

Literal

Enter the temperature coefficient for each conducting layer [1/K].

Relative Permeability of Conductors

REAL

Literal

Enter the relative permeability of the corresponding conductor.

Relative Permeability of Insulation

REAL

Literal

Enter the relative permeability of the corresponding insulating layer.

Semi-Conducting Layers

Choice

Select whether or not there are semi-conducting layers present in this cable. Semi-conductor layers may only be included between the core and 1st conducting layers.

Inner Semi-Conductor Layer Thickness

REAL

Literal

Enter the thickness of the inner semi-conducting layer (between insulator and core conductor) [m].

NOTE: This value should not be included as part of the conductor or insulator dimensions. The line constants program will take care of the semi-conductor layer automatically, given this thickness.

Outer Semi-Conductor Layer Thickness

REAL

Literal

Enter the thickness of the outer semi-conducting layer (between insulator and 1st conducting layer) [m].

NOTE: This value should not be included as part of the conductor or insulator dimensions. The line constants program will take care of the semi-conductor layer automatically, given this thickness.