Question

The earthing transformer is used:
(1) To avoid the harmonics in the transformers
(2) To provide artificial neutral earthing where the neutral
points of the 3–phase system are not accessible
(3) To improve the current capacity of neutral
(4) To increase the neutral current to ground in case of
fault

Answer 1

2 is the answer to the question

Answer 2

EARTHING TRANSFORMER

Earthing transformer is used TO PROVIDE ARTIFICIAL NEUTRAL EARTHING WHERE THE NEUTRAL POINTS OF THE 3- PHASE SYSTEM ARE NOT ACCESSIBLE

FEATURES OF EARTHING TRANSFORMER:

* A grounding transformer, also known as an earthing transformer, is a three-phase auxiliary transformer that provides a ground line to either an ungrounded wye or a delta-connected system.

* Grounding transformers are part of the network's earthing infrastructure. By providing a return channel for current to a neutral, they allow three-phase (delta linked) systems to support phase-to-neutral loads.

* Grounding transformers are typically made up of a single winding transformer with a zigzag winding design, however a wye-delta winding transformer can also be used.

* Generators in power plants and wind farms frequently use neutral grounding transformers. Neutral grounding transformers are used in high-voltage (sub-transmission) systems when the circuit would otherwise be without a ground, such as at 33 kV.