Extreme high power density T-modular-multilevel-converter for medium voltage motor drive

摘要

The objective of the concept of T-type Modular Multilevel Converter (TMMC) is to improve the power density of the traditional Modular Multilevel Converter (MMC) exploited in medium voltage motor drive. The size of the major volume contributor “capacitor” can be reduced by 30%~40% with the proposed circuit operating at only half dc link voltage at low frequency low voltage region, which is enabled by an extra full bridge arm inserted between the middle point of the dc and the terminal of the output in each phase leg. It is also found to be a topology that is optimized for usage of SiC device because of its zero requirement for device serialization and its modest dv/dt and di/dt level.