Driver Integrated Fault-Tolerant Reconfiguration after Short-On Failures of a SiC MOSFET ANPC inverter phase

Fault-tolerant converters are required for applications with a high risk of damage or financial loss, like electric aircraft or energy transmission systems. The Active Neutral Point Clamped (ANPC) inverter is a fault-tolerant multilevel topology, which enables an ongoing degraded operation after single semiconductor failures, if no secondary failures caused by over-voltage and short-circuit currents occur. This paper investigates the critical failure scenarios of a three-level ANPC inverter prototype built with 650 V SiC MOSFETs. Innovative driver integrated measures for immediate short-circuit detection, over-voltage clamping and switching strategy reconfiguration in order to enable a reliable ongoing operation are presented. Thus, a very efficient and fault-tolerant inverter for applications with high availability requirements can be realized.