High-Reliability ANPC Inverter with Fault Diagnosis and Fault-Tolerant Control for Renewable Energy Systems

This paper proposes a short-circuit (SC) fault diagnosis and fault-tolerant control strategy to address the reliability issues of active neutral-point-clamped (ANPC) threelevel inverters in renewable energy systems. This study utilizes the DESAT signal from driver chips to locate the faulty switch and establishes a mapping table between DESAT signals and SC switching tubes, enabling microsecond-level rapid fault identification. A dual-mode fault-tolerant strategy is designed: the derated mode maintains symmetrical line voltage output through phase reconstruction, while the rated mode achieves fullvoltage operation. Simulation results demonstrate that the system retains three-phase symmetry and stable operation after a singleswitch SC fault.