The Effect of Thermal Aging on Dielectric Properties and Tracking Erosion Test of Micro Bn Composites

Abstract

The increasing of load will cause the increasing stress that experienced by the equipment which this stress causes deterioration in the equipment insulation, and eventually will causes a breakdown. One of the stresses faced by insulation is thermal. In this study, epoxy resin will be combined with one type of inorganic filler which has high thermal conductivity, namely Boron Nitride with a ratio of 10wt% and 20wt% respectively. To examine the resistance of the micro-composite material to thermal stress, accelerated thermal ageing with a temperature of 150°C was carried out for 500 h. To investigate the effect of thermal ageing on micro-composite materials, dielectric properties testing (relative permittivity, dielectric loss and breakdown voltage) carried out at 100h interval. Tracking erosion test was also conducted to determine the effect of high thermal conductivity filler on materials for 6 h following IEC standard, and also the thermal distribution measurement using the infrared thermal camera was taken in 1 h interval to observe the hotspot temperature in each interval. From the experiments conducted, it was found that with the incorporation of BN micro-composite and accelerated thermal ageing at 150°C for 500h did not significantly influence the dielectric properties of the material. However, significant differences were obtained in tracking test which from the results of the thermal distribution, the hottest spot temperature and carbonisation pattern are clearly known that by adding BN micro-composite can improve thermal conductivity in the material.