An autotransformer is an electrical transformer having only single winding which acts as both primary and secondary, so in input and output connected to shared single winding.
Why do we need to go for Auto Transformer?
We have some advantages of auto-transformer over normal two winding transformers.
- Autotransformers usually smaller in size, because one winding is eliminated.
- As size is small cost also low(so cheap in cost)
- As the winding is same so leakage reactance will be less.
- Increased kVA rating.
Construction, Principle of Operation Of Auto Transformer:
Copper Savings in Auto Transformer:
If we compare conventional two winding transformers and autotransformer the amount of copper needed for autotransformer is less.weight of copper of any winding depends upon its length and cross-sectional area.and length depends on no.of turns, cross-sectional area varies with rated current.
Let’s assume, Wa and Wtw are weight of copper in autotransformer and two winding transformers respectively,
∴ Wtw -Wa=kWtw