| PhD Viva

Name of the Speaker: Mr. Manoj Dhivakar J (EE21D010)
Guide: Dr. Sarathi R
Online meeting link: https://meet.google.com/zbc-iyfb-uek
Date/Time: 30th June 2025(Monday), 4:00 PM
Title: UNDERSTANDING THE ELECTRICAL, MECHANICAL AND THERMAL PROPERTIES OF ATH/LMGP FILLED SILICONE RUBBER COMPOSITES FOR OUTDOOR INSULATORS

Abstract :

Silicone rubber (SR) insulators exhibit excellent dielectric, hydrophobic, and mechanical properties compared to traditional porcelain and glass insulators. However, under prolonged environmental stress, they are prone to degradation phenomena such as arcing and flashovers. Incorporating 5 wt% aluminium trihydrate (ATH) identified as the optimal loading to maintain mechanical integrity. Further performance improvements are achieved by introducing low melting glass powder (LMGP) alongside ATH, resulting in a 59.34% increase in thermal conductivity, a 13.03% rise in tensile strength, and a higher degradation temperature of 520 °C. Finite element modeling (FEM) confirms that these fillers effectively reduce surface hotspots and erosion. At temperatures above 400 °C, LMGP contributes to the formation of a protective ceramic layer, significantly enhancing erosion resistance.

This study also explores the behavior of ATH/LMGP-filled SR composites under corona discharge conditions. Corona exposure leads to increased surface roughness and higher dielectric losses. Thermographic analysis proves valuable for early fault detection and localization. Additionally, a neural network model utilizing Haralick texture features from thermal images achieves 96.8% accuracy in predicting material aging, demonstrating the potential of AI-assisted diagnostics for advanced condition monitoring of outdoor insulators.