Influence of the Geometrical Parameters of Power Transformer Insulation on the Frequency Domain Spectroscopy Measurement

With the advancement in digital technology, diagnostic techniques based on dielectric relaxation methods e.g. frequency domain spectroscopy (FDS) are currently being widely used by the power utilities for the assessment of the condition of power transformer oil-paper insulation. However, it has been observed that the results of these tests are highly influenced by several factors, more important among them are the temperature of the insulation, moisture, ageing, acidity and even by the geometry of transformer cooling duct. Efforts have been made to study the individual effects of temperature [1, 2], moisture, ageing and acidity [3] on the FDS measurements. A perusal of current literature reveals that the investigations on the effects of geometrical parameters (dimensions of spacer barrier in oil duct) on FDS characteristics have not been studied extensively. Opportunity has therefore been taken of the current situation by the authors to suggest an alternative experimental method to get this information by conducting experiment on a proto-type insulation model.