Investigation of the Insulation Characteristics of the UV-A Stressed Polyamide Composite Insulation for High Voltage Application /

Abstract

Polyamide (PA) and its nanocomposites containing zinc oxide (ZnO) have exhibited promising characteristics suitable for electrical insulation applications, particularly in indoor settings such as high voltage cables and motor insulation. However, these insulation materials are often exposed to elevated levels of UV radiation, which can lead to the degradation of polyamide-based insulators and a subsequent decline in their electrical performance. This study aimed to analyze the impact of UV-A aging and DC electric stress on the dielectric properties of neat polyamide (PA-0), as well as polyamide-ZnO nanocomposites with varying ZnO content (1wt% PA-1, 3wt% PA-3, 5wt% PA-5, and 7wt% PA-7).Accelerated aging conditions were simulated in a specialized chamber for 200 hours, with intermediate analyses conducted at 100-hour intervals. The dielectric properties, including relative permittivity (εr), dissipation factor (tan δ), and resistivity, were evaluated, considering their temperature and frequency dependencies. The findings revealed that an increase in temperature led to higher εr and tan δ values, with PA-3 demonstrating superior performance among all the nanocomposites. The investigation of frequency-dependent dielectric properties showed that εr and tan δ decreased with an increase in frequency, with PA-1 exhibiting better results.These values remained within acceptable limits, meeting the requirements for effective insulating materials in indoor applications. Furthermore, the incorporation of ZnO had a positive effect, with the nanocomposites surpassing the performance of pure polyamide. The presence of ZnO nanoparticles likely contributed to this enhancement by preserving the composite structure or increasing the surface area and surface energy, making these materials promising candidates for indoor electrical insulation.