Compared to ordinary power transformers, special transformers must structurally meet special operating conditions (such as high frequency, high voltage, high current, or harsh environments). Their core components include:
Core: High-permeability silicon steel sheets or amorphous alloy materials are used to reduce eddy current losses. For example, the core of an electric furnace transformer needs to withstand high temperatures and often uses cold-rolled silicon steel sheets (thickness 0.23-0.3mm, refer to IEC 60404-8 standard).
Windings: Divided into high-voltage windings and low-voltage windings, the materials are mostly copper or aluminum foil. Rectifier transformer windings need to consider harmonic effects and adopt a multi-layer shielding structure.
Insulation System: Includes oil-immersed (mineral oil or synthetic ester) and dry-type (epoxy resin casting). For example, the insulation class of traction transformers is usually H-class (temperature resistance 180℃).
Cooling System: Air-cooled, oil-cooled, or water-cooled design. High-power electric furnace transformers often employ forced oil circulation cooling (flow rate up to 2000L/min, refer to GB/T 6451).
