Thermal Conductivity and Dielectric Properties of High Thermal Conductivity Adhesive for Large Generator Stator Bars

High thermal conductivity (HTC) adhesive is the basis to improve the thermal conductivity of the main insulation material for large generator stator bars. HTC adhesive is prepared by using Tung oil anhydride bismaleimide-epoxy resin (TAB-EP) as matrix and hexagonal boron nitride (h-BN) with different particle sizes is being as thermal conductive filler. It has been researched that thermal conductivity, dielectric properties and breakdown voltage of the HTC adhesive are influenced by the particle size and amount of h-BN. The results show that the thermal conductivity of the composites increased with the increase of the particle size and amount of h-BN filler. The h-BN made the relative permittivity and dielectric loss factor of the composites increase as temperature rising. Though h-BN filler causes the DC (Direct Current) breakdown strength decreasing, AC (Alternating Current) breakdown strength have no obvious been effected by h-BN. Therefore, the h-BN can be using to improve the adhesive thermal conductivity without affecting the electrical properties of the adhesive.