A transformers is a device for converting electric energy at one voltage level to electric energy at another voltage level through the action of a magnetic field. It plays an extremely important role in modern life by making possible the economical long-distance transmission of electric power.
Most power system transformers fall into two types of construction, dry-type or liquid-immersed type. Dry-type include air insulated and solid insulated construction. Solid insulation is usually epoxy resin. Liquid-immersed types use various forms of oil and special synthetic liquids. This transformers usually have some form of external radiator to dissipate the heat generated internally by the windings and the core. The radiator is often the surfaces of the tank specially folded into corrugated fins, or is in the form of fins, which are attached to the tank sides.