Cascaded h-bridge (chb) converter for medium-voltage (mv) srm drives

A cascaded H-bridge (CHB) converter system for driving a multi-phase switched reluctance motor (SRM), the SRM comprising a predetermined number of phases (m), the system comprising:

• a plurality of cells arranged into m phase legs, each phase leg corresponding to a respective phase winding of the SRM, wherein at least two phase legs share one or more of the cells, wherein the shared cells are associated with phases that are not conducted simultaneously during any commutation interval;
• each cell comprising a plurality of switching elements and a corresponding DC voltage supply;
• and
• a controller configured to selectively control the switching elements of the cascaded cells of each phase leg to produce, at an output of the corresponding phase leg, a plurality of discrete phase voltage levels for operating the SRM in a plurality of operating modes, wherein the number of discrete phase voltage levels provided by each phase leg equals 2n+1.

A method of generating a plurality of discrete phase voltage levels for driving a switched reluctance motor (SRM) using a cascaded H-bridge (CHB) converter system, the SRM comprising a predetermined number of phases (m), wherein the system comprises:

• a plurality of cells arranged into m phase legs, where each phase leg comprises a predetermined number (n) of cells cascaded in series, where n is greater than or equal to 1, and wherein each phase leg corresponds to a respective phase winding of the SRM;
• each cell comprising a plurality of switching elements and a corresponding DC voltage supply;
• and
• a controller coupled to the plurality of cells,
• wherein the method comprises:
• selectively controlling, using the controller, the switching elements of the cascaded cells of each phase leg;
• and
• generating, at an output of the corresponding phase leg, the plurality of discrete phase voltage levels for operating the SRM in a plurality of operating modes, wherein the number of discrete phase voltage levels provided by each phase leg equals 2n+1.