Investigation on the effects of Irgamet 39 on stray gassing generation in the insulating oil

The addition of metal passivator into oil-paper insulation has been widely used to control the sulfur corrosion. Aminomethyl substituted toluylbenzotriazole (Irgamet 39) is considered to be the most effective passivator to inhibit sulfur corrosion hazard in the oil-immersed power equipment. However, relevant studies and project examples indicated that adding the benzotriazole passivator and its derivatives to the oil-immersed power equipment leads to the abnormal of stray gases in oil. In this paper, the accelerated ageing experiment of oil-paper insulation with and without Irgamet 39 was conducted at
$\mathbf{130 ^{\circ}\mathbf{C}}$
, the composition and content of dissolved gases in oil was measured. The depletion of Irgamet 39 during the thermal ageing process and the content of copper ions dissolved in the oil were also measured and analyzed. The results showed that the addition of Irgamet 39 into the insulating oil leads to the abnormal of stray gases in oil. Compared with the oil-paper without Irgamet 39, the content of H
2
, CO and CO
2
dissolved in oil with 100mg/kg Irgamet 39 showed an uptrend and the content of hydrocarbon gases showed a trend of slight decrease and then rise during the thermal ageing process. Combined with the depletion trend of Irgamet 39 and the content of copper ions dissolved in oil during the thermal ageing process, the effects of Irgamet 39 degradation and aerogenesis on the stray gases formation was preliminarily discussed and analyzed.