What Do You Know about Three-phase oil Immersed Transformer？

The core part of the three-phase oil-immersed transformer is composed of the closed core and the windings set on the core column. In addition, there are core, oil tank, winding, oil storage cabinet, bushing, breather, explosion-proof tube, heat sink, tap changer, gas relay, thermometer, oil purifier, etc. The next three-phase oil-immersed transformer supplier mainly introduces the core, oil tank and winding.

(1) Iron core

The core is the magnetic circuit part of the transformer. In order to reduce the hysteresis and eddy current loss in the core, the core is made of 0.35mm ~ 0.5mm thick silicon steel laminated, the surface of silicon steel laminations are coated with insulating paint or use the surface oxide film to insulate the laminations from each other. The upright part of the core of a three-phase transformer is called the core column, in which the low-voltage winding and high-voltage winding of the transformer are set; the horizontal part is called the iron yoke, which is used to form a closed magnetic circuit.

The oil tank is the shell of the transformer, the core, windings are installed inside and filled with transformer oil. For larger capacity transformers, the outside of the tank is equipped with heat sink or heat pipe.

(2)Oil tank

The oil tank is the shell of the transformer, the core and winding are installed inside and filled with transformer oil. For larger capacity transformers, the outside of the oil tank is equipped with heat sink or heat sink tube.

Transformer oil is a good insulating performance of mineral oil, it has two roles: one is insulation, transformer oil insulation performance than air, winding dipped in oil can improve the insulation performance everywhere, and avoid contact with air, to prevent winding moisture; two is the role of heat dissipation, the use of oil convection, the core and winding heat generated through the box wall and heat sink tube to the outside. Transformer oil is divided into three specifications of No.10, No.25 and No.45 according to its freezing point, which is -10℃, -25℃ and -45℃ respectively, and is generally chosen according to local climate conditions.

(3) Winding

The winding, also called a coil, is the circuit part of the transformer, divided into two kinds of windings: primary and secondary. The winding connected to the power supply is called the original winding, and the winding connected to the load is called the secondary winding. The original and secondary windings are made of copper or aluminium wire wrapped with high-strength insulation. Each phase of the original and vice winding of the three-phase transformer is made of the cylindrical set on the same core column, the low voltage winding with few turns is set inside near the core, and the high voltage winding with many turns is set outside the low voltage winding. This is placed because the low-voltage winding is easier to insulate the core. Low-voltage winding and core and high-voltage winding and low-voltage winding are isolated by the sleeve made of insulating material to insulate them reliably. In order to facilitate heat dissipation, a certain gap is left between the high and low windings as an oil channel, so that the transformer oil can flow.