US 6,982,884 B1
Autotransformers to parallel AC to DC converters
Derek Albert Paice, 114 Rosewood Ct., Palm Harbor, Fla. 34685 (US)
Filed on Aug. 23, 2004, as Appl. No. 10/924,122.
Int. Cl. H02M 7/00 (2006.01); H02M 1/12 (2006.01)
U.S. Cl. 363—44 11 Claims
OG exemplary drawing
 
1. A multiple AC/DC converter system comprising multiple, 3-phase, wye-connected autotransformers with neutrals isolated from each other and constructed to exhibit high zero-sequence impedance, having three windings on each of 3 phases with two windings being connected in series to provide a tapped coil with one section of the coil being connected to form a neutral with the same coils from the other phases; with the tapping point being connected to one of the three power source lines; with the same connections on the other phases such that each of the lines of the 3-phase source are connected to the tapping point on each transformer phase; with one winding from another phase being connected to the end of the tapping furthermost from the neutral point; with the longer part of the tapped coil being called a LONG winding; with the shorter part of the tapped coil being called a TEASER winding; with the remaining coil connected to the end of the TEASER winding remote from the tapping being called a ZIG winding; with the proportionality of the turns comprising the LONG, TEASER, and ZIG windings being selected so as to achieve output voltages remote from the junction of the ZIG coil and the TEASER coil, that meets design requirements concerning amplitude and phase angle relative to the supply voltage; with such design requirements including amplitude generally equal to that of the 3-phase supply voltage and with phase angles of plus or minus generally Φ° depending upon phase rotation or connection, with respect to the supply voltage; wherein three output voltages of predetermined amplitude and phase are available from each of n or (n−1) transformers, where n is the number of 3-phase bridge converters.