please reply tertiary winding

If you've got three separate windings on a transformer they are called...

Primary, secondary and tertiary windings, so what is the question?

John.

thanks a lot Mr. John for response...my aim is to know about possible advantages and purposes of tertiary windings..hoping for quick reply

What is the minimum value of power transformer Beyond which tertiary winding has to be provided?

which factors decide provision of Tertiary winding?

A transformer has either 2 or 3 windings regardless if its 3 phase or single phase. a two winding will have a primary and secondary winding and a 3 winding transformer will have tirtiary winding. e.g. lets say we need 132kV/33kV/11kv transformer, this means a transformer has three windings. but we can also opt for an auto transformer which will have two windings , the second winding will have tappings to choose from 33kV and 11kV.

there are special type of transformers which are having only one winding. they are called earthig transformer/Zig-zag transformer. These are used in industrial environement for having zero sequence path for isolated electrical systems. Though most of the transformers are 2 or 3 windings,Transformer neednot be limited to 2 or 3 windings. there can be n number of windings. There are many installations with more than 3 in drive applications. I have witnessed 21 winding transformer!!!.

The tertiary windings will not provide significant power, they are used in metering and control circuits only.

Tertiary winding is used to counter the flux created by the DC component or zero sequence component which would cause reduction in secondary winding. These windings are used generally in large capacity transformers used for transmission purpose or in large industrial sub-stations, but definitely not in distribution sector. Tertiary winding is always connected in delta. It is true that it is used for metering control circuits, main purpose of tertiary is not for loading and hence generally not loaded or lightly loaded.