Development and Validation of a Multivariate Calibration Method for Determining Interfacial Tension of Transformers Insulating Oils by near Infrared Spectroscopy

Abstract

all rights reserved transformers are critical elements for the transmission and distribution of energy in electricity power systems. they are expected to operate for up to 40 years and a transformer's life is actually the life of the internal insulation system, which consists of Kraft paper immersed in insulating mineral oil. Kraft paper is composed of cellulose (about 90%), hemicelluloses and lignin. cellulose degrades slowly with the ageing of the transformer and the polymer chains break down, releasing degradation products into the oil. 1 Insulating oils are composed of naphthenic, paraffinic and minor amounts of aromatic hydrocarbons, and can be degraded producing carboxylic acids. the main transformer ageing accelerators are moisture, oxygen and heat. thermal ageing of the Kraft paper is the critical life-limiting process, and its main

UV-Vis Spectroscopy: A New Approach for Assessing the Color Index of Transformer Insulating Oil

“…To assess the degradation level of transformer oil using optical sensing techniques, researchers either determines the special characteristic of degraded transformer oil in the spectrum [ 16 ], or the change in concentration of certain content in transformer oil, such as inhibitor content [ 17 ] and furanic compounds [ 18 ], or the change in properties of transformer oil such as interfacial tension [ 20 ]. The color of the transformer oil can also be used to assess the degradation level of the transformer oil [ 7 , 21 ].…”