Epoxy Systems for Dry-Type Transformers

Dry-type transformers are manufactured by embedding coils and metal conductors in epoxy resin. The epoxy material offers excellent electromechanical properties and chemical resistance, but it is characterized by high modulus and brittleness. Additionally, the significant difference in thermal expansion coefficients between the epoxy polymer and the metal coils/conductors poses challenges. During the thermal curing process, factors such as curing shrinkage, high process temperature, ambient temperature fluctuations, and high-temperature rise under electrical loads can lead to multidimensional coupled internal stresses. This, combined with stress-induced degradation of the insulation due to mechanical, electrical, and thermal effects, introduces reliability risks to the product. The quality and performance of epoxy resin are critical, as they directly determine the reliability of cast-resin transformer products.

XRUN's epoxy resins for dry-type transformers are classified as follows:
● By Thermal Class: F-grade and H-grade.
● By Supply Form: Epoxy resin formulations (ready for filler addition).
● Pre-filled epoxy resin compounds (pre-mixed with fillers).
● By Operating Temperature: Standard type (for general environments).
● Ultra-low-temperature resistant type (for extreme cold conditions).
● By Thermal Conductivity: Standard type, High-thermal-conductivity type.
● By Flame Retardancy: Standard type. Flame-retardant type.