Terahertz Detection of Heat Aging of Silicone Rubber Based on PCA-RF

Composite insulator is a key component used in electric power system, which is widely used in electric power equipment with its excellent resistance to dirt flash and aging. Silicone rubber, as the main insulating material for composite insulators, has excellent hydrophobicity, aging resistance and galvanic corrosion resistance. However, composite insulators are exposed to various natural environments such as ultraviolet rays, humidity, pollution, temperature changes, etc., for a long time outdoors, and the silicone rubber will gradually age, resulting in a decrease in its insulating properties, which affects the reliability and service life of the insulators. In this study, silicone rubber for composite insulators was fabricated and aged for 80 days at <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$200^{\circ} \mathrm{C}$</tex>. The samples of silicone rubber with different aging times were examined using a terahertz time-domain spectroscopy system to obtain its absorption in the frequency range of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0-3$</tex> thz, and a reduced dimensional regression of the silicone rubber absorption was performed using PCA-RF to obtain the relationship between the absorption of silicone rubber and the number of aging days.