Transformers are classified by use

1) Power transformer: used for the rise and fall voltage of power transmission and distribution system.

2) Instrument transformer: such as voltage transformer, current transformer, measuring instrument and relay protection device.

3) Test transformer: can produce high voltage, high voltage test for electrical equipment.

4) Special transformers, such as furnace transformers, rectifier transformers, adjusting transformers, capacitive transformers, phase-shifting transformers, etc.