A 48-pulse converter using dc-ripple injection

This paper presents a 3-phase, voltage-sourced, 48-pulse converter. The converter results from the combination of a series connected 12-pulse voltage- sourced rectifier with a passive voltage injection circuit, a passive current injection circuit and a bi-directional switch. The voltage and current injection circuits each use a single-phase rectifier bridge and a single-phase transformer circuit. Both the injection circuits and the bidirectional switch operate at six times the supply frequency and have a low rating. In this paper the converter operation is explained, analysed and simulated.