What is the difference between a 6-pulse and 12-pulse transformer?
A 6-pulse transformer has a single 3 phase output voltage. Generally it is Wye connected and the primary is Delta connected. A 12-pulse transformer has two 3 phase secondary windings. They are generally phase shifted 30ยบ which allows for currents that combine in the primary winding, cancelling out much of the 5th, 7th and 11th etc. harmonics.
