Protection of Transformer

 The power transformer is costly equipment and highly reliable pieces of equipment of the Sub-station. So, the protection of the transformer is the most vital. Different types of faults may occur in the transformer, if the fault sustains for a long time, the transformer will damage. Therefore, it is required to trip the transformer from both ends i.e H.V & L.V side of the transformer as soon as possible when any fault occurs. The power transformer should also be protected from lightning surges, switching surges, arcing grounds, etc. For protecting from the surges, lightning arresters are used at both ends of the transformer.

The other different protections for the transformer are given below:

1. Over-current and Earth fault protection.
2. Differential protection for transformer.
3. Differential magnetic-balance protection.
4. Restriction Earth fault (REF) protection.
5. Buchholze Relay protection.
6. Thermal protection ( i.e WTI & OTI protection ).
7. Pressure released Device ( PRD ) protection.
8. Fuse Protection.