Transformer is an important electronic device that is indispensable for power equipment, electronic appliances, circuits, etc. It has a wide range of applications and a wide range of types. The types of commonly used transformers can be summarized as follows:

Ⅰ. Phase transformers can be divided into single-phase transformers and three-phase transformers:

1. Single-phase transformer: used for single-phase load and three-phase transformer group.

2. Three-phase transformer: used to increase and decrease the voltage of a three-phase system.

Ⅱ. According to the cooling method, it can be divided into dry-type transformer and oil-immersed transformer:

1. Dry-type transformer: Relying on air convection for cooling, generally used for small-capacity transformers such as local lighting and electronic circuits.

2. Oil-immersed transformer: Relying on oil as the cooling medium, such as oil-immersed natural cooling, oil-immersed air cooling, oil-immersed water cooling, forced oil circulation, etc.

Ⅲ. According to the purpose, it can be divided into power transformers, instrument transformers, test transformers, and special transformers:

1. Power transformer: used to increase and decrease the voltage of the power transmission and distribution system.

2. Instrument transformers: such as voltage transformers, current transformers, measuring instruments and relay protection devices.

3. Test transformer: It can generate high voltage and conduct high voltage test on electrical equipment.

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

Ⅳ. According to the winding form, it can be divided into two-wire group transformer, three-winding transformer and autotransformer:

1. Double winding transformer: used to connect two voltage levels in the power system.

2. Three-winding transformer: generally used in power system regional substations, connected to three voltage levels.

3. Autotransformer: used to connect power systems with different voltages. It can also be used as an ordinary step-up or step-down transformer.

Ⅴ. Divided into core transformers, amorphous alloy transformers, and shell transformers according to the iron core form:

1. Core transformer: power transformer used for high voltage.

2. Amorphous alloy transformer: Amorphous alloy iron core transformer is a new type of magnetic material, and its no-load current is reduced by about 80%. It is currently a distribution transformer with ideal energy saving effect, especially suitable for rural power grids and developing areas Places with lower rates.

3. Shell-type transformers: special transformers used for large currents, such as electric furnace transformers, welding transformers; or power transformers for electronic instruments, televisions, radios, etc.