Design and comparison of cascaded H-bridge, modular multilevel converter and 5-L active neutral point clamped topologies for drive application

This paper investigates the design procedure of cascaded H-bridge (CHB), modular multilevel converter (MMC) and five-level active neutral point clamped (5-L ANPC) topologies for medium-voltage and high-power industrial motor drive application. The design is performed using 1.7-kV insulated gate bipolar transistor (IGBT) technology for CHB and MMC converters, and utilizing 3.3- and 4.5-kV IGBTs for 5-L ANPC topology. When designing the converters, the effect from leakage parameters of the multi-pulse transformer used together with the diode front-end rectifier stage is taken into account via a model. Also comparison is done between the designed converter topologies at three different voltage levels: 4.16-, 6.9- and 13.8-kV (only first two voltage levels in case of 5-L ANPC) and three different power levels: 1-, 3- and 5-MVA. The comparison is done from several points of view like capacitance requirements, diode front-end and inverter stage losses, semiconductor rating, semiconductor die size and parts count.