Effect of metal and paper inclusions on mineral oil degradation

Understanding the chemical changes induced by the stresses prevalent in the insulation systems of high voltage power plant allows the engineer to intercede prior to catastrophic failure. The materials included in the insulation of oil-filled plant varies with plant design, this variation may be the reason for discrepancy between indicated condition monitoring results and those found during forensic examination. The experiments undertaken in this work suggest that knowledge of the components of the insulation system will provide a better basis for future analyses and interpretation of faults. This document shows that (1) the presence of copper and aluminum with paper in oil-filled insulation systems affects DGA and FTIR results and (2) that batch differences in oil from a single supplier can affect the degradation indicators.