Open-Circuit Fault Diagnosis and Fault-Tolerant Control for Coupled-Inductor-Based Aalborg Inverter

In this paper, an open-circuit fault diagnosis and fault-tolerant control method of SiC-MOSFET for the coupled-inductor-based Aalborg inverter is proposed. The method detects open-circuit faults by calculating the slope of the sampling current, and identifies the faulty SiC-MOSFET devices through a reconfiguration control algorithm. In any operating mode of the coupled-inductor-based Aalborg inverter, when the high-frequency switch tube has an open-circuit fault, the inverter can be reconfigured as a Fly-Back-type or Fly-Boost-type converter to continue operating. The proposed method enhances the reliability of the inverter and does not require additional sensors or diagnostic circuits, thus not increasing the cost of the overall system.