Miscibility Synthetic esters are miscible with mineral oil as well as ester oils in any proportion. Synthetic esters can not be used to retro-fill silicone oil-filled units. Silicone oil mixed with esters can cause foaming during the filling of a transformer under a vacuum. The mixture of mineral oil and synthetic esters differ from both …
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What are the typical data for a paper-synthetic ester insulating system? FIG 1: Moisture equilibrium curves for cellulose paper and synthetic ester, Midel 7131 A higher temperature will ensure that a shorter time is needed to reach a moisture equilibrium state. At lower temperatures, this can take much longer to achieve. A single measurement of …
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Hydrolysis of Kraft paper is indicative of the breakdown of the kraft paper system. It was found that five different acids may be present in aging transformers. These include Formic acid, Acetic Acid, Levulinic Acid, Stearic Acid, and Naphthenic acid. Low molecular weight acids are absorbed by the kraft paper, the high molecular acids remain …
Comparing mineral and ester oil aging behavior Electrical, thermal, mechanical, and chemical stress leads to the aging of insulating liquids. Breakdown of the hydrocarbon chain of transformer liquids generates soluble gases and a colloidal suspension. This suspension aids the further oxidation of the oil. Oxygen contributes to the formation of soluble oxidation products as well as …
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Pressboard aging in different insulating liquids Abstract:There is a move in the industry to more and more alternative liquids because they have virtually no impact on the environment. But what happens in the transformer? We will focus on the different impacts each of these types of oil has on the pressboard in the transformer. To …
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The health indices are an objective and quantitative representation of the health of the asset incorporating data obtained by operating observations, field inspections, site, and laboratory testing. This is a powerful tool for asset management and identifying and prioritizing investment needs. This is clearly set out in budget planning and capital application. The maintenance program …
Continue reading “Health Index Determination for Power Transformer – Part II”
Abstract: The Health Index rating of power utility assets has become somewhat of a buzz-word. We will take some time to evaluate this phenomenon and the practical value to the industry. The Health Index is used by industry to describe asset health status and then through this determines the asset management actions that need to be implemented …
Continue reading “Health Index Determination for Power Transformers – Part 1”
I am very excited to start this project as it has been a dream for a long time… The compiling of various topics in a central location, hopefully, to serve as a reference source to many maintenance and technical personnel in the distribution and power transformer industry. Various articles would be incorporated over time that …
