Open-Circuit Fault Detection and Identification in Neutral Point Clamped Inverter via Sliding Mode Observers

Abstract

Neutral 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.