Influence of different metal materials on the gas production characteristics of insulating oil

Mineral oil is the most commonly used fluid for the insulation of power transformers and has excellent physicochemical and electrical properties. Dissolved gas analysis (DGA) is commonly used in transformers as a fault identification method to monitor the operating condition of the transformer and to detect faults. However, in oil-immersed power transformers, metal materials such as copper, alloys and silicon steel are used in parts such as windings and cores, which can have an impact on dissolved gases in mineral oil. The effect of the different metals present in oil-immersed transformers on the dissolved gases in the insulating oil was explored. The results show that alloys and silicon steel contribute to the production of H
2
and copper contributes to the production of CO and C
2
H
4
. When the tests were carried out to 70 days, the C
2
H
4
gas content in the mineral oil samples containing copper strips at 120 °C was 22.19 times that at 90 °C. This paper provides the data basis and experimental proof for investigating the effect of metals on the gas production characteristics of transformer insulating oil.