Medium voltage multilevel converters for ship electric propulsion drives

An increasing number of ships are being integrated with electric propulsion systems and a significant proportion of these require variable frequency drives in the multi-megawatt range. At such large power, medium voltage AC (MVAC) drive offers numerous advantages over low voltage AC (LVAC) solution. This paper examines the state-of-the art MV drives and their development trends for marine applications. Further, a review is carried out on multilevel converter (MLC) topologies suitable for high power ship propulsion drives. A variety of topologies are evaluated for marine applications based their specific requirements. From the review, it is concluded that hybrid solution seems the most attractive option for the specified application.