Single Switch Open-Circuit Fault Detection for Three-Level NPC Inverter Using Conducted Emissions Signature

This paper proposes a single switch open-circuit fault diagnosis approach for three-phase three-level NPC inverter based on conducted emissions. The proposed approach uses a simple electromagnetic interference (EMI) filter, placed between the DC source and the conversion system, to meter conducted interferences. A time-domain analysis of the voltages across the EMI filter resistors is, firstly, utilized to identify the two pair semiconductors among the two upper or the two lower switches. The Teager energy operator based algorithm is, then, applied. This latter proves the efficiency of this method for the identification of the faulty switch. The effectiveness of this pioneering approach is enhanced by simulation results.