The Distribution Transformer is used to bring down or step down the voltage and current level of a transmission line to a predefined level, which is called the safety level for the end-user consumer in domestic and industrial purposes.
Power transformers are used in transmission networks of higher voltages for step-up and step-down applications. Distribution transformers are used for lower voltage distribution networks as a means to end user connectivity.
The power transformer always operates on rated full load as the load fluctuation is very less, but the distribution transformer is operated at a load less than full load as the variation in the loads is very high.
Power transformers are used in power generating stations and transmission substations, and the distribution transformer is installed at the distribution stations from where the power is distributed for industrial and domestic purposes.
In power transformers, the primary winding is always connected in star and secondary winding in delta connections while in distribution transformers, the primary winding is connected in delta and secondary in star connection.
The size of the power transformer is large as compared to the distribution transformers. In Power Transformer, the iron and copper losses take place throughout the day but in a distribution transformer, the iron loss takes place 24 hours i.e., throughout the day, and the copper losses depend on the load cycle.