Research on the Interfacial Characteristics of Epoxy Resin Optical Fiber Composite Insulators

The fiber optic composite insulator is a critical component of optical current transformers, serving both optical signal transmission and insulation functions. However, fiber optic insulators often fail due to their interface problems. This study systematically compares the interfacial performance of silicone rubber fiber optic composite insulators and newly developed epoxy resin fiber optic composite insulators through dye penetration and water diffusion tests. The results indicate that the silicone rubber fiber optic composite insulator fails the dye penetration test and undergoes interface breakdown after 100 hours of boiling due to moisture infiltration. Both dye penetration and interface breakdown predominantly occur at the contact surfaces between the polytetrafluoroethylene (PTFE) fiber sheath and epoxy resin filler, as well as between the fiber sheath and the core rod. In contrast, the epoxy resin fiber optic composite insulator successfully passes both the dye penetration and water diffusion tests, demonstrating superior interfacial performance. This study provides new insights into the evaluation and improvement of interfacial performance in fiber-optic composite insulators.