Characteristics of multiple additives inhibited oil with copper dissolution under accelerated ageing

This paper presents multiple additives inhibited oil´s behavior with copper dissolution under the accelerated thermal ageing according to IEC 61125. Insulating transformer oil has sulfur content in it and it tends to oxidize easily. Hence for the past few years antioxidant is added for oxidation inhibition and metal passivators are added to reduce sulfur attack on the metal parts. Multiple additives used here is the ready sample of certain amount mixture of antioxidants, metal passivators and transformer oil in proportion. Copper dissolute oil´s critical characteristics are analyzed under different proportions of copper added based on copper ions. Then inhibited copper dissolute oil is added with mixture of additives (sulfur inhibitor) and their critical characteristics are analyzed. Oxidation properties, oil´s different behavior and paper degradation are analyzed by the addition of sulfur inhibitor with the obtained critical characteristics.