60 Planning the electrical installation
Selecting the grid-side power cabling principle
This section presents three alternative principles for the grid-side power cabling.
ļ® Alternative 1: Symmetrical, shielded three-phase cable(s)
ļ® Alternative 2: Cable bus system
The connection of a high current (> 300 A) cable bus system that consists of several
cables is shown below. In this system, less conductor material is needed due to better
cooling of separate conductors.
L1
L2
L3
N
Transformer Converter
L1
L2
L3
PE
PE
Wind turbine main earthing busbar
2)
1)
1)
2) Not used if the supply
cable screen operates
as a protective
conductor.
1) As short as possible for
low inductance
L1
L3
L2
It is recommended to arrange the cables as shown
ā alongside each other ā to achieve a current
distribution as accurate as possible. Gaps between
cables are required for cooling.
L1
L3
L2
L1
L3
L2
L1
L3
L2
L1
L3
L2
N
L1
L3
L2
NL1
L3
L2
N
L1
L2
L3
N
L1
L2
L3
PE
PE
Wind turbine main earthing busbar
Note: Current derating of the cables is required when installing the cables in a cable tray.
This derating factor must be taken into account as per the local electrical safety code.
Transformer Converter