Importance of Transformer oil www.rajasthanpower.in
Transformer oil • Used in oil-filled transformers. • It has an excellent insulating properties. • It has both insulating and cooling properties. • It secures the transformer from severe damages and losses.
Importance of transformer oil • It provides the chemical stability to ensures long lasting service. • Transformer oil permits good transfer of heat. • It provides high electric strength to the transformers.
Types of Transformer oil Types of Transformer oil Naphtha transformer oil Paraffin Transformer oil
Naphtha transformer oil • Easily get oxidized than Paraffin oil. • Oxidation product has made i.e. the sludge which is more soluble in naphtha than paraffin oil. • The sludge made in naphtha oil does not precipitate at the bottom of the transformer, thus it does not obstruct the transformer to work efficiently.
Paraffin transformer oil • Oxidation of paraffin oil is low as compared to naphtha oil. • The pour point of paraffin oil is high due to the presence of wax content in it. • The sludge made in paraffin oil is insoluble which obstruct the cooling system of transformer.
Parameters to choose the best transformer oil • Chemical Parameters: includes Sludge content, Acidity, and WaterContent • Electrical Parameters: includes Dielectric Strength, Specific Resistance, and Dielectric Dissipation Factor. • Physical Parameters: includes viscosity, Flash point, inter facial tension, and pour point.
Chemical Parameter • Acidity:Acidity reduces the insulation of paper insulation in winding. Acidity is the most deleterious property of transformer oil . Acid causes rust on iron when it comes in the contact of moisture. • Water Content: The Water content, which presents in transformer oil affects the dielectric properties of oil and besides also influence the paper.
Electrical Parameters • Specific resistance: It is the measure of direct current resistance between two opposite sides of one cu. Cm of oil. • Dielectric Strength: Dielectric strength is the measure of the breakdown voltage of transformer oil. • Dielectric dissipation Factor: It is also called as loss factor or Tan Delta of Transformer Oil
Physical Parameters • Flash Point of transformer Oil: Flash point indicates the value of temperature at which the air get mixed up with the vapours of oil and comes up with the inflammable mixture. The temperature is normally more than 140deg. C. • Inter Facial Tension: The inter facial tension indicates the molecular attractive force between oil and water. • Viscosity of Transformer Oil: It is defined as obstruction offlow of oil at normal condition. It is the restriction of convection of oil inside the transformer. The transformer oil should be of low viscosity so that it shows the minimum hurdle to the flow of oil.