Home SCIENCE 3D Animation How 3 Phase Transformers Work

3D Animation How 3 Phase Transformers Work


How do 3 phase transformers work, why are three phase transformers used, how do they produce 480V, 277V, 240V, 208V and 120V. What is wye delta, open delta and high leg delta. What is a pad mounted and pole mounted transformer and how is three phase electricity generated?

source.image: The Engineering Mindset

A transformer is a device used to change the voltage of electric power. Power plants generate power at a low voltage, but power needs to be at a very high voltage for the long trips down the wires from the generator to your house. At a residence the voltage of the power has to drop back down again so that it will not be dangerous and so appliances will not be blown out. A transformer allows the power to change voltages from place to place.

Transformers use a coil of wire in one circuit (primary coil) wrapped around a soft iron core and second coil of wire in another circuit secondary coil. When an alternating current passes through the primary coil this creates a changing magnetic field which induces an alternating potential difference across the secondary coil. If that secondary coil is connected in a circuit it will produce an alternating current.


a three-phase transformer consists of three primary coils and three secondary coils and is represented as 3-phase or 3ɸ. A three-phase system can be constructed using three individual identical single-phase transformers, and such a 3-phase transformer is known as the bank of three transformers. The working of the 3-phase system is similar to a single-phase transformer, and they are normally employed in power generation plants. Three-phase transformers play an important role in the power transmission system.