Fault-Tolerant Inverter Operation Based on Si/SiC Hybrid Switches

The silicon (Si)/silicon carbide (SiC) hybrid switch comprising a Si insulated gate bipolar translator (IGBT) and a SiC metal-oxide-semiconductor field effect transistor (MOSFET) in parallel offers not only excellent performance and cost tradeoff but also inherent switch-level redundancy for potential power converter fault-tolerant operation. It is possible to operate the power converter even when either the SiC MOSFET or the Si IGBT experiences an open-circuit fault. This article first analyzes various switch failure scenarios and then proposes a novel fault-tolerant control strategy for a single-phase inverter based on the Si/SiC hybrid switches to mitigate a single-point switch failure and maintain inverter operation. Experimental results validate the effectiveness of the proposed fault-tolerant control strategy.