What are the General Principles for Transformer Protection Installation?

What are the General Principles for Transformer Protection Installation?

1. Prevent gas from short circuit inside the transformer iron case and low oil level.

2. The defense transformer coil and lead line phase short circuit, large grounding current power grid side coil lead side grounding short circuit and coil turns between the vertical differential protection or current velocity break protection.

3. Defense transformer external phase short circuit and make gas protection and vertical differential protection backup over current protection (or compound voltage start over current protection, or negative sequence current protection).

4.Zero-sequence current protection against external grounding short circuit in large grounding current power grid.

Overload protection against symmetric overload.