Core: The core is made of high magnetic permeability grain oriented cold-rolled silicon steel sheet. The core is a new type of core, a fully oblique joint stacked core, the core column is a multi-step circular section, and the iron yoke and the core are of equal section. Winding: The winding adopts corrugated oil channel, non-painting process, and tightening belt binding, the windings are all concentric coils: the high-voltage winding has a tap corresponding to the tap voltage requirements, which is led to the tap switch. The switch is installed on the box cover, and the tap voltage can be changed only after the power is cut off. Safety protection device: 30-2000kVA transformers are equipped with pressure relief valves. A gas relay with alarm and trip terminals can be installed according to user needs. Oil temperature measuring device: The transformers are equipped with glass thermometer tube holders, which are located at the top of the oil tank and extend into the oil 120±10mm. 1000~2000kVA transformers are equipped with outdoor signal thermometers. Transformer oil tank: The transformer oil tank is composed of corrugated walls, and the surface is dust-sprayed and the paint film is firm. The corrugated heat sink not only has a cooling function, but also has a "breathing" function. The elasticity of the corrugated heat sink can compensate for the change in transformer oil volume caused by temperature rise and fall. Therefore, the fully sealed transformer has no oil storage cabinet, which reduces the overall height of the transformer. The transformer adopts a vacuum oil filling process when encapsulating, which completely removes moisture in the transformer and the transformer oil does not come into contact with the air. It effectively prevents oxygen and moisture from invading the transformer, which may lead to a decrease in transformer insulation performance and aging of transformer oil, so oil sample tests are carried out from time to time.
