How To Properly Insulate A Power Transformer: Everything You Need To Know

Power Transformer

janvier 10, 2022

For a power transformer to function correctly and not cause harm to people using it, it should be well insulated. Insulation is one of the essential components of the entire transformer unit. A poorly insulated power transformer is prone to over-voltages. Having the coils close to one another without insulation can cause accidents. Additionally, poor insulation is the cause of most electrical equipment and systems failure. The insulation material's quality is crucial in determining the success of the insulation process.  

All About A Power Transformer Insulation: A Simple Guide

First, Ensure You Have All The Necessary Equipment

A good power transformer insulation material should be chemically stable to avoid disintegration and degradation, no matter what conditions it is exposed to. They should have excellent properties to withstand high electrical frequency and voltage impulses, whereby a unidirectional voltage fluctuates to a peak and then to a low value. An insulation material's mechanical stability and strength will ensure that the material can withstand the electromagnetic strains caused by short circuits and overloads. Insulating material should also withstand the high temperature caused by the mechanical operation of a power transformer.  

Power Transformer Insulation Materials

Silicon is used to laminate the transformer cores, oil, and cellulose paper. Different materials are used for different insulating parts of the transformer based on their voltage levels. The insulator oil can either be mineral-based oil or vegetable-based oil. Vegetable oil is more famous for power transformers due to its eco-friendliness and because vegetable-based oil insulation allows the insulation paper to absorb more moisture, increasing the longevity of the power transformer insulation. Mineral-based oils like naphthenic oil are effective in the power transformer insulation process. They can reduce the excessive rise in temperature in the transformer windings, thus allowing it to operate at its best level while controlling overheating. The power transformer emits a lot of heat as it operates. The point of insulating power transformers is to separate the parts of the transformer to avoid danger or destruction when there are emissions like heat or disparities in voltage levels during the functioning of the transformer.  

Liquid Immersion Cooling To Reduce Transformer Heat

To reduce this heat and maintain its normal functioning and temperature, the transformer can also be cooled to avoid insulation aging and damage. There are various ways of cooling a transformer to insulate it, the most influential being immersion cooling. In this process, the power transformer is immersed in a non-conductive liquid to transfer the excess heat emitted by the transformer to the fluid and maintain the required temperatures for the optimal functioning of the transformer. The preferred liquid for the liquid immersion cooling for a power transformer is air and oil. They ensure that the transformer does not experience winding. Immersion cooling is more effective than air cooling in time, efficiency, and energy consumption.  


With information on the importance of insulation, the materials used to separate transformer parts, and the process of immersion cooling, you can properly insulate a power transformer.