20/25 MVA Oil-filled Transformer Transformer is an electrical static machine whose aim is to increase and decrease an Alternative Voltage. Runs on magnetic affect, without any part being in motion. Usefulness of Transformers The transport of electrical energy at high voltage allows to convey less current in the lines (P = 3 V I cos ). For given amount of losses, transportation under limited current, allows to use conductors with lower cross sectional areas, i.e. cheaper! Also structures that can stand these conductors will be less restrictive because a lower cross sectional area also means a reduced weight. That is why it is cheaper to transform the voltage and use intermediate voltages, especially when distances become longer… The transformer also provides a galvanic insulation, i.e.. the primary and