Muhammad Ramees, M.K.P.Saywan, Y.A.Ahmad, M.W.2026-02-0620232023 IEEE International Conference on Power Electronics, Smart Grid, and Renewable Energy: Power Electronics, Smart Grid, and Renewable Energy for Sustainable Development, PESGRE 2023, 2023, Vol., , p. -https://doi.org/10.1109/PESGRE58662.2023.10405188https://idr.nitk.ac.in/handle/123456789/29321Neutral point clamped (NPC) inverters offer a range of advantages, including reduced switching loss, decreased harmonic distortion in output voltage, minimized emissions impact, and improved efficiency. However, System reliability becomes a significant concern in NPC inverters due to their higher susceptibility to failures due to the increased number of power electronic switches in comparison to conventional two-level inverters. Power electronic switch faults, particularly open circuit faults, can potentially lead to cascaded failures within the system. To address this issue a sliding mode observer-based method is proposed in this paper. The effectiveness of the method is evaluated through detailed simulations using MATLAB/Simulink. The results demonstrate the capability of the sliding mode observer in accurately detecting open switch faults, contributing to enhanced fault diagnosis and improved reliability of NPC inverters. © 2023 IEEE.Neutral Point Clamped (NPC) InverterOpen circuit Fault DiagnosisSliding Mode Observer (SMO)