Enhanced Fault-Tolerant Control for Open Circuit Faults in Three-Phase Multilevel Inverters

Multilevel inverters (MLIs) are commonly used in high-power applications to improve efficiency, reduce harmonics, and enhance power quality.However, their reliability is often compromised by open-circuit faults, particularly in switching devices, such as IGBTs.This research focuses on developing a modified fault-tolerant structure for a 5-level MLI, designed to mitigate the effects of open-circuit faults in three-phase power systems.The proposed structure incorporates real-time fault detection and reconfiguration techniques, allowing the system to continue operating with minimal performance degradation, even after a fault occurs.The system design ensures that the fault is isolated and alternative switching paths are activated, allowing for continuous power delivery.MATLAB/Simulink simulations were performed to validate the performance of the proposed system.The results show that the modified fault-tolerant MLI maintains stable output voltage and current waveforms, with only a minor increase in the total harmonic distortion (THD) after a fault is detected.A comparative analysis demonstrated the superiority of the proposed solution over traditional 5-level MLI designs in terms of fault detection speed, reconfiguration efficiency, and overall system performance.