Study of ageing and protecting factors concerning the paper/oil insulation

An original approach based on the method of experiment design in dynamic mode is proposed in order to study the effect of ageing factors on the paper/oil insulation in power transformers. The relevant calculations are described. The influence of the effects of each factor (temperature, oxygen pressure, catalyst and antioxidant) is quantified and discussed. Finally, a comparative study of three classes of antioxidant (phenols, amines and thiols) enabled the classification of these additives according to their reactivity and their efficiency with respect to the protection of mineral insulating oils and the depolymerization mechanisms of paper.<
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