A novel fault diagnosis methodology in modular multilevel converters to enhance reliability and resilience

In high-power applications like high-voltage DC transmission and renewable energy systems, the modular multilevel converter (MMC) is an essential part. Despite its advantages, the MMC is vulnerable to short-circuit issues (SC), particularly in insulated gate bipolar transistors (IGBTs), This may result to severe operational disruptions if not promptly addressed. The article in question suggests a novel fault diagnosis methodology for MMCs that merges fault detection and localization to enhance system reliability. Fault detection (FD) is achieved through Root Mean Square Current Comparison (RMS-CC), which identifies abnormalities in RMS current waveforms. For fault localization (FL), the Hilbert transform is applied to individual capacitor voltage signals, enabling precise identification of faulted IGBTs. This combined approach enhances the reliability and resilience of MMCs by facilitating rapid and accurate fault management. The efficiency of the suggested fault diagnosis approach in protecting MMC-based systems is demonstrated by simulation results, which confirm its robustness and dependability.