Electrical and Mechanical Properties of Polyamide/ Polyester Composites

Isolation system integrity is perhaps the most important factor in the satisfactory changes in transformer performance and improvements in transformer isolation systems that occur continuously. Thermal and electrical degradation properties in an Insulation paper has been inspected to improve reliability and to enable preventative maintenance technology in transformers. This paper deals with the experimental studies on the electrical and mechanical properties of aramid paper with different concentrations of polyester (0%, 30%, 50%, 60%, and 70%). The dielectric strength (kV/mm) of aramid/polyester was tested in several thermal conditions such as 25, 70, and 100°C, and the dielectric strength of aramid/polyester was tested after being exposed to thermal aging for 24 hours in high temperatures (150°C and 220°C). The electrical resistivity (ohm. cm) was carried out. Also, a tensile strength test was applied under different aged conditions to check the various properties of aramid/polyester samples. The results showed that the electrical and mechanical properties of the insulation paper modified by adding polyester. Maximum values of AC dielectric strength, electrical resistivity, and tensile strength were obtained from 60% of polyester content.