Fault Diagnosis Method for Cascaded H-bridge Multilevel Inverters under Switching Device Failure

This paper presents a new method for the fault detection and localization in a single-phase cascaded H-bridge multilevel inverter (CHBMI). Open-fault case of one of the controllable components is considered. Simulations show the possibility to visually distinguish the fault features compared with the normal operation. Recurrence Plot (RP) technique and Recurrence Quantification (RQ) analysis are used for data extractions corresponding to defects, giving information and a respectable correlation between the inverter output voltage waveforms and the given defects. Simulation results confirm the effectiveness of the proposed fault diagnostic approach, which might be used to extract a general fault diagnosis method to detect and locate the fault in higher level CHBMI.