Novel topologies of 24-pulse rectifier with conventional transformers for phaseshifting

Two 24-pulse rectifier topologies 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. 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. The four three-phase systems are mutually displaced from each other by 15°. Each three-phase system feeds a 6-pulse diode rectifier and the four diode rectifiers are series cascaded to provide a 24-pulse dc output voltage. PSCAD based simulation and experimental results that confirm the design efficacy are presented.