PARTS OF VOLTAGE TRANSFORMERS (VT) USED IN GAS INSULATED SUBSTATION (GIS) BASICS AND TUTORIALS

PARTS OF VOLTAGE TRANSFORMERS (VT) USED IN GAS INSULATED SUBSTATION (GIS)
What Are The Parts Of Voltage Transformers (VT) Used In GIS?


VTs are inductive types with an iron core. The primary winding is supported on an insulating plastic film immersed in SF6.

The VT should have an electric field shield between the primary and secondary windings to prevent capacitive coupling of transient voltages.

The VT is usually a sealed unit with a gas barrier insulator. The VT is either easily removable so the GIS can be high voltage tested without damaging the VT, or the VT is provided with a disconnect switch or removable link

PARTS OF CURRENT TRANSFORMERS (CT) USED IN GAS INSULATED SUBSTATION (GIS) BASICS AND TUTORIALS

PARTS OF CURRENT TRANSFORMERS (CT) USED IN GAS INSULATED SUBSTATION (GIS)
What Are The Parts Of Current Transformers (CT) Used In GIS?


CTs are inductive ring types installed either inside the GIS enclosure or outside the GIS enclosure. The GIS conductor is the single turn primary for the CT.

CTs inside the enclosure must be shielded from the electric field produced by the high voltage conductor or high transient voltages can appear on the secondary through capacitive coupling.

For CTs outside the enclosure, the enclosure itself must be provided with an insulating joint, and enclosure currents shunted around the CT.

Both types of construction are in wide use.