In the rewinding with the option, lap winding is often preferred to be used as it includes all the same coils.
This is quite acceptable if it results in the same amounts of flux per pole as the original winding.
Flux distribution through the core is achieved much better in double layer windings as compared to a single layer.
But the beauty of transformers is that they allow us to have more than just one winding in either the primary or secondary side.
Transformers which have more than one winding are known commonly as multiple winding transformers.
The principle of operation of a multiple winding transformer is no different from that of an ordinary transformer.
Advantages
- Improvement in efficiency or at least maintained.
- All coins are subjected to equal air flow for better cooling.
- Uniformly placed phase insulations and coil bracing.
- Nature of MMF curve much resembles a sine wave.