Patent ID: 8625316

Claim:
A neutral point clamped (NPC) power converter fault protection system, comprising: a DC bus; a switching network connected to the DC bus, the switching network including at least two leg circuits, each of the at least two leg circuits including: at least two switches connected in series and two NPC diodes, each of the two NPC diodes corresponding to one of the at least two switches, each of the at least two switches having an open position, the two NPC diodes connected between a corresponding one of the at least two leg circuits and the DC bus; and a control module in communication with the switching network, the control module including: a first control logic for monitoring the switching network to detect a fault condition, the fault condition indicating that one of the two NPC diodes of the one of the at least two leg circuits is non-operational; a second control logic for switching the at least two switches of each of the at least two leg circuits to the open position; a third control logic for determining a position of a non-operational NPC diode if the fault condition is detected; and a fourth control logic for maintaining one of the at least two switches in the open position.