Why do we use star connection on transmission and distribution on delta?
Answer:
The star connection is mainly required for the Power Transmission Network
for longer distances, whereas in delta connection mainly in Distribution networks and is used for shorter distances.
For long-distance transmission and distribution, star connection is preferred because it requires little insulation and has a neutral that helps to balance the circuit.
Delta connections require more insulation and have issues with unbalanced currents, hence they are preferable for transmission and distribution over shorter distances.