Enhanced high voltage insulation performance of HTV silicon rubber nanocomposites filled with nano-TiO₂ for outdoor...

This study focuses on the performance evaluation of silicone rubber (SR) nanocomposites fabricated using industry-standard molding and thermal compression techniques. Nanocomposite insulator specimens were synthesized with nano-TiO₂ doping concentrations of 0%, 1%, 3%, 5%, and 7% by weight. The DC resistance measurements of the nanocomposites exhibited a distinct range from 211.33 GΩ to 161.16 GΩ with increasing nano-filler content. Notably, a 7% nano-TiO₂ loading yielded the highest dielectric constant at both 0 Hz and 2 MHz. Partial discharge (PD) testing indicated that the 5% nano-TiO₂ composite exhibited a 24.1% increase in inception voltage, signifying improved resistance to electrical stress due to the enhanced charge distribution and stabilization effects introduced by nano-filler incorporation. The observed variations in PD inception voltage were attributed to the interplay between doping levels and local charge diffusion dynamics, which modified the electric field distribution. Thermal stability assessments revealed significant modifications in degradation kinetics upon TiO₂ nanoparticle inclusion, as determined via thermogravimetric analysis (TGA). Differential scanning calorimetry (DSC) demonstrated a 38% reduction in polymer flow rate between - 50 °C and 100 °C, indicative of endothermic transitions. Mechanical property evaluations showed that the 5% TiO₂-filled composite exhibited the lowest tensile force durability (41.2 N) and tear strength (18.72 kN/m). A comprehensive performance assessment highlights the enhanced operational reliability and longevity of HTV-SR nanocomposites, making them viable candidates for outdoor high-voltage insulator applications.