Study on breakdown characteristics of nano-modified transformer oil at low temperature

Abstract

Studying the breakdown characteristics of nano-modified transformer oil at low temperature is helpful to improve the breakdown voltage of transformer oil at low temperature. The breakdown characteristics of oil samples under different voltage forms, different temperatures and different water contents at-30 ∼30 °C were studied by using a relatively perfect test system. The results show that in the test temperature range, the breakdown voltage of the oil sample decreases first and then increases, and there is a minimum value. Under the three moisture contents of 26 ppm, 61 ppm and 85 ppm, the breakdown voltage of pure oil and nano-oil is the lowest when the moisture content is 85 ppm. The addition of nano-materials increases the breakdown voltage of oil samples, and the increase is small near zero degrees Celsius. When the water content is 26 ppm, the average increase rate is 8.57 %. The average increase rate is 14.35 %. The largest increase is above zero, with an average increase rate of 19.6 %. Nanomaterials reduce the dispersion of breakdown voltage of transformer oil. Compared with pure oil, the dispersion reduction rate is about 1.03.

Keywords

• Transformer oil
• Low temperature
• Nano-modification
• Breakdown characteristics