Auto-connected hexagon transformer for a 12-pulse converter

In a 12-pulse static converter for converting three-phase alternating current (AC) power into direct current (DC) across a positive and a negative DC output terminal, with a polygonal succession of windings forming a regular hexagon with hexagon windings and with 12 rectifying devices equally distributed about 12 successive tappings from said windings and at 30 degrees to one another;

• the combination of:
• three AC input terminals connected to said hexagon windings at 120 degrees to one another;
• and
• a set of three windings symmetrically and centrally disposed within said hexagon windings and coupled thereto in a delta mode;
• each of said hexagon windings including a central winding means disposed between two equally placed side windings of lesser ampere-turn ratio for cooperating with said three windings on said delta mode to reduce harmonic current in said direct current.