Why Can't Epoxy Resin Insulators Be Used In Ultra-high Voltage Lines?

In power system design, the environmental and electrical stress conditions of transmission lines directly affect the selection of high voltage epoxy resin. For ultra-high voltage (UHV) lines, environmental pollution and extreme electric field requirements place more stringent demands on insulation materials, and high voltage standoff exhibits significant limitations under these conditions.

Under the long-term operating conditions of outdoor UHV lines, the surface of epoxy resin materials is easily affected by environmental factors. Sunlight exposure, temperature and humidity cycles, and contaminant deposition accelerate surface aging, degrade surface electrical properties, form a conductive contaminant layer, and alter the surface electric field distribution. Compared to traditional materials such as ceramics, epoxy resin lacks an effective inherent self-cleaning mechanism.