1. According to the number of phases:
1. Single-phase transformer: used for single-phase load and three-phase transformer group.
2. Three-phase transformer: used to raise and lower the voltage of the three-phase system.
2. According to the cooling method:
1. Dry-type transformers: rely on air convection for natural cooling or increase fan cooling, and are mostly used for small-capacity transformers such as high-rise buildings, high-speed toll stations, local lighting, and electronic circuits.
2. Oil-immersed transformers: rely on oil as the cooling medium, such as oil-immersed self-cooling, oil-immersed air-cooled, oil-immersed water-cooled, forced oil circulation, etc.
3. According to the purpose:
1. Power transformer: used for voltage rise and fall of power transmission and distribution system.
2. Instrument transformers: such as voltage transformers, current transformers, used for 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 furnace transformers, rectifier transformers, adjusting transformers, capacitive transformers, phase-shifting transformers, etc.
Fourth, according to the winding form:
1. Double winding transformer: used to connect two voltage levels in the power system.
2. Three-winding transformer: generally used in substations in the power system area, connecting three voltage levels.
3. Autotransformer: used to connect power systems of different voltages. It can also be used as an ordinary step-up or step-down transformer.
Five, according to the core form:
1. Core-type transformer: used for high-voltage power transformers.
2. Amorphous alloy transformer: Amorphous alloy iron core transformer is made of new magnetic conductive material, and the no-load current is reduced by about 80%.
3. Shell-type transformers: special transformers for high current, such as electric furnace transformers, welding transformers; or power transformers for electronic instruments, televisions, radios, etc.
Transformer is a device that uses the principle of electromagnetic induction to change the AC voltage. The main components are the primary coil, the secondary coil and the iron core (magnetic core).
The main functions are: voltage transformation, current transformation, impedance transformation, isolation, voltage regulation (magnetic saturation transformer), etc. According to the purpose, it can be divided into: power transformers and special transformers (electric furnace transformers, rectifier transformers, power frequency test transformers, voltage regulators, mining transformers, audio transformers, intermediate frequency transformers, high frequency transformers, impact transformers, instrument transformers, electronic transformers , reactors, transformers, etc.).