You should always keep in mind the role that life is the life of the transformer, and therefore the main concern we have when a maintenance policy is set , is to keep the paper in the best conditions.
Degree of polymerization ( dp ) : a new transformer insulation paper has a dp on the order of 1200 and this declines as you age to reach values of the order of 200 , reducing the tensile strength thereof.
By liquid chromatographic analysis , one can determine the content of furan compounds in the oil , the presence of which show a thermal stress of the paper. There is a direct correlation between the amount of furan compounds and the degree of polymerization ( DP ) achieved .
The furan compounds formed by the degradation of cellulose , are soluble in the oil. And by means of liquid chromatography can be determined qualitatively and quantitatively the following compounds:
5 – Hydroxymethyl -2- Furfural
2 – Furfural
2 -Acetyl Furano
5 – Methyl-2- Furfural