Main parts of a power transformer include the magnetic core, primary and secondary windings, tank, insulating oil or solid insulation, bushings, conservator, radiators, tap changer and protection devices. The core guides magnetic flux, while windings carry current and produce or receive induced voltage. Oil or resin provides insulation and cooling. Bushings safely bring conductors through the tank wall. The conservator accommodates oil expansion. Radiators and fans or pumps remove heat. Tap changers adjust turns ratio. Relays, gauges and sensors monitor temperature, gas formation and oil levels for safe operation.