in distribution transformer why conversion is star to delta??

Question

what is the advantages of this

Answer 1

With the step up transformer each of the primary coils will induce to a secondary. Coil Voltage will be stepped up as per coil ratio, as occurs with a single phase. One advantage of the star on primary and delta on secondary is the difference between coil voltage and line voltage. By having the secondary connected in delta there is a further increase of line voltage by root 2. This is nearly 50% increase and reduces no of turns and current etc.

Answer 2

In distribution transformers the conversion is delta to star, it is not star to delta. As for as distribution tranformers are concerned the power is received with higher voltage in the delta connected primary winding to limit the transmission loss as there is no 4th conductor for the neutral point.

Where as in secondary side, the system is divided as single phase and three phase supply system. Hence a 4th conductor, a common point, with proper earthing arrangement for ensuring safety and proper functioning of the single/ three phase equipments is required

Answer 3

For local domestic distribution of power we generally only need a single phase. Also, for safety reasons it is rather nice to have a supply tied to earth rather than just floating. A star configuration meets these requirements.

For long distance transmission it is nice to save money on wires. A delta configuration requires 3 wires not 4 and so meets these requirements.

Answer 4

Distribution Transformers are Delta to Star not Star to Dalta. we required single phase supply for domestic use.with star both single phase and three phase supply can get also star common point can earth to get the protection and balance supply

Answer 5

In 220/380V distribution, a star type requires inductors capable of sustaining 220V only, but with a high current.
A Delta configuration will require slightly larger inductors (capable of taking 380V, but with a lower current (sqr(2) less).
Hence, in the delta wiring, the current through the inductors is lower (for the same power) and so is the loss by joule effects.