Furanic Compounds in GSU Power Transformer Oil as an Indicator of Paper Ageing
“The analysis of furanic compounds in transformer oil has gained significance in transformer life assessment as a potential alternative to depolymerisation degrees (DP) determination of paper samples and a method for measuring it using High Perfomance Liquid Chromatography (HPLC) has been standardised (IEC 61198).
Degradation model development using basic researches, and remaining life estimation, are essential for modern electrical engineering aging-asset management programs. However, the majority of publications on this topic are based on small-scale laboratory investigation with very little on field experience with power transformers and all of them find certain correlation between DP-value of paper and furfural (2FAL) in oil.
Analysis from transformers in service and from repair transformers supports this correlation in certain way. However, the relationship between furanic compounds in oil and remaining life time assessment is very complex. The content of furanic compounds in the oil depends on operation temperature, transformer design, type of oil and paper.
It is not possible to predict the remaining life of a transformer only based on the content of furanic compounds, for this reason, the aim of this report will be shows analysis data from hundreds of GSU power transformer, combining DGA, physics-chemical characterizes of oil, time in service and furanic compounds.
To understand the ageing mechanism of solid insulation and to construct a model to predict the life expectancy of oil-immersed power transformers, it is needed to define a select group of type of transformers. During the maintenance proceedings several parameters are determinates. As the general mechanism, contents of CO, CO2, physic–chemical parameters and Furfural may be gotten in the lab. This kind of experiments combined with the statistical analysis of thousands data of DGA and Furfural of operating transformer collected, will be conduce to important conclusion. Generally, there is a rather large difference of the value of Furfural content measured between the transformers operated in power plant and in substation.
Based on experimental results, previous investigations, the data measured and tendency of the tested transformer, comparing with these statistical distribution curves, the analysis and diagnosis of paper insulation will be carried on.