Enhancing the dielectric characteristics and DC flashover of epoxy resin composites by surface modification of AgNbO₃...

The advancement of industrial technology has led to power modules facing challenges such as elevated temperatures, high voltages, and increased frequencies. The conventional epoxy resin (Ep) fails to satisfy the demands of high voltage and superior insulation. This study involved the synthesis of Ep resin/ AgNbO₃ nanocomposites aimed at addressing insulating flaws. AgNbO₃ was modified using the silane coupling agent KH550. The changes in the molecular chain after incorporating of unmodified and modified AgNbO₃ were evaluated through FTIR analysis. The SEM results indicate that following modification, AgNbO₃ particles are evenly distributed within the Ep resin matrix, demonstrating a lack of agglomeration. From thermal conductivity result it was found that modification of AgNbO₃ shows an enhancement of thermal conductivity, attributed to the reduction of interfacial phonon scattering and thermal resistance within the Ep resin. Additionally, the dielectric constant and dielectric loss in composites are greatly impacted by the addition of AgNbO₃. According to the DC breakdown strength result, the addition of modified AgNbO₃ enhanced the process and caused deeper traps to form inside the bulk matrix. The distribution of trap energy levels is determined by Thermal Stimulated Depolarization Current (TSDC), which indicates that the incorporation of AgNbO₃ results in an increase in trap energy levels. Furthermore, the incorporation of 1 wt% AgNbO₃ particle into Ep resin has been observed to enhance the energy level of deep traps. After AgNbO₃ was added, DC Flashover in both air and vacuum significantly increased in comparison to pure Ep resin.