24-pulse rectifier topology with 3-phase to four 3-phase transformation by novel interconnection of conventional 3-phase and 1-phase transformers

A 24-pulse rectifier topology based on phase shifting by conventional magnetics is proposed. Four 3-phase systems are obtained from a single 3-phase source using novel interconnection of conventional single- and 3-phase transformers. From two 30° displaced 3-phase systems feeding two 6-pulse rectifiers that are series connected, a 12-pulse rectifier topology is obtained. Thus, from the four 3-phase systems that are displaced by 15° two 12-pulse rectifiers are obtained that are cascaded to realize a 24-pulse rectifier. Phase shifts of 15° and 30° are made using phasor addition of relevant line voltages with a combination of single-phase and three-phase transformers respectively. PSCAD based simulation and experimental results that confirm the design efficacy are presented.