Modular multilevel current source and voltage source converters to increase number of output current levels and output voltage levels

A modular multilevel converter configured to:

• increase one of number of an output voltage level and an output current level, wherein said modular multilevel converter is one of a modular multilevel voltage source converter and a modular multilevel current source converter;
• wherein said modular multilevel voltage source converter comprises:
• a plurality of legs, wherein each said leg comprises a plurality of arms;
• wherein each said arm comprises a main wave shaping (WS) circuit, an auxiliary WS circuit and an arm inductor;
• wherein said main WS circuit comprises at least one half bridge sub-module, wherein at least one said half bridge sub-module comprises a capacitor;
• wherein said auxiliary WS circuit comprises at least one full bridge sub-module, wherein at least one said full bridge sub-module comprises a capacitor;
• wherein said modular multilevel voltage source converter is configured to:
• increase number of output voltage levels based on number of said full bridge sub-modules in said auxiliary WS circuit;
• and
• wherein said modular multilevel current source converter comprises:
• a plurality of legs, wherein each said leg comprises a plurality of arms;
• wherein each said arm comprises a plurality of half-bridge modules connected in parallel, a plurality of arm capacitor connected across said plurality of half-bridge modules and at least one auxiliary full bridge module;
• and
• wherein said modular multilevel current source converter is configured to:
• increase number of output current levels based on at least one auxiliary full bridge module, wherein said at least one auxiliary full bridge module comprises an inductor and a plurality of semiconductor switches;
• and
• wherein said modular multilevel current source converter is configured to insert said auxiliary full bridge modules in order to increase number of said output current levels based on inductor current in said auxiliary full bridge module and polarity of voltage in each arm.