Aging of transformer winding insulation is an important concern in the asset management of transformers.  York Analytical Laboratories has developed an in-house method to assist utilities determine the useful life of their electrical transformers.

The method involves High Performance Liquid Chromatography (HPLC) analysis of the transformer oil for certain degradation products of transformer winding paper insulation known as Furanic compounds.

The functional relationship between Furanic compounds in the transformer oil and the degree of polymerization are used to predict the current condition and useful life of the transformer without removing the transformer from service.

There are several factors that contribute to transformer winding insulation aging but temperature is generally the most important factor as it influences not only the aging of the paper, but also aging of the oil.

As the paper insulation ages, it loses some of its mechanical strength, becoming more susceptible to tearing or bursting. Once mechanical damage of the insulation has occurred, movement of the conductors is likely, resulting in changing voltage stresses and electrical discharge. These eventually could lead to catastrophic failure in the transformer.

Contact us at clientservices@yorklab.com to discuss the needs of your utility clients.