All-copper, national standard production, power transformer, distribution transformer, oil immersed power transformer, dry epoxy cast power transformer, primary energy efficiency, secondary energy efficiency, tertiary energy efficiency, etc. As per IEC 60076 Part-1, a Power transformer is defined as a static piece of apparatus with two or more windings which, by electromagnetic induction, transforms a system of alternating voltage and current into another system of voltage and current usually of different values and at the same frequency to transmit electrical power. Power Transformers can alter from one voltage to another at high power levels. It is used in the transmission grid to step down voltage from higher to lower voltage levels.