System and method for detecting IGBT failure in a multi-level converter using gate-emitter voltage sensing

A multi-level bridge power converter with a plurality of phase legs, comprising:

• a first converter and a second converter coupled together via a DC link, each of the first and second converters comprising a plurality of switching devices;
• and
• a controller configured to operate the first and second converters, the controller comprising at least one processor, the at least one processor configured to perform a plurality of operations, the plurality of operations comprising:
• receiving a commanded state for a gate of one or more of the plurality of switching devices;
• receiving a gate-emitter voltage of the one or more of the plurality of switching devices, the gate-emitter voltage referring to a voltage from the gate to an emitter of the one or more of the plurality of switching devices;
• comparing, via at least one comparator of the controller, the gate-emitter voltage of the one or more plurality of switching devices to a reference voltage range corresponding to the commanded state for the gate of the one or more of the plurality of switching devices;
• determining an actual state of the gate of the one or more of the plurality of switching devices based on the comparison;
• and
• implementing a control action based on the actual state of the gate of the one or more of the plurality of switching devices.