Some basics of transformers

What are the types of power transformers? What are the main components?

A: With the development of the power system, the demand for power transformers is getting higher and higher, there are many kinds. According to the number of phases, there are single-phase and three-phase; according to the location of the windings and the core of the inner core type and outer core type; according to the cooling method, there are dry-type self-cooling, air-cooled, forced oil circulation air-cooled and water-cooled, etc.; according to the level of insulation at the neutral point, there are full-insulation and half-insulation; according to the winding material, there are five levels of insulation, such as A, E, B, F, H. The transformer can be divided into load-regulated and load-less voltage regulation, and the transformer has different requirements for operation. Different kinds of transformers, there are different requirements for the operation; according to the voltage regulation can be divided into on-load voltage regulation and no-load voltage regulation.

General power transformer main components are: iron core, winding, casing, tank, oil pillow, radiator and its ancillary equipment.

What are the safety protection facilities for transformer body construction? What is its main function?

A: Transformer body construction in the protection facilities are:

(1) Oil pillow

Its capacity is about 8-10% of the transformer oil volume. The role is: to accommodate changes in the volume of transformer oil due to temperature changes, limit the contact between transformer oil and air, reduce the degree of oil moisture and oxidation. The oil pillow is installed on the moisture absorber to prevent air from entering the transformer.

(2) Moisture absorber and oil purifier

Moisture absorber, also known as respirator, internal adsorbent, silica gel type activated alumina, which is often put into a part of the discoloration of silica gel, when changed from blue to red, indicating that the adsorbent has been damp, must be dried or replaced.

Oil purifier, also known as the filter, net oil cylinder filled with adsorbent, silica gel type activated alumina, etc., when the oil through the oil purifier and adsorbent contact, which water, acid and oxides are absorbed, so that the oil is clean, prolonging the service life of the oil.

(3) Explosion-proof tube (safety airway)

Explosion-proof tube is installed on the cover of the transformer box, as a release protection against high pressure in the oil tank in case of internal failure of the transformer.

Modern large transformers have adopted pressure release valve instead of safety airway. When a fault occurs inside the transformer pressure rises, the pressure release valve operates and connects the contacts to alarm or trip.

In addition, the transformer also has gas protection, thermometer, oil meter and other safety protection devices.