A Generalized Fault Tolerant Multilevel Inverter for Switch Open-Circuit Faults

This paper presents a multilevel inverter (MLI) with fault tolerant capability for an open-circuit fault in any switch. The proposed inverter with six uni-directional switches and one bi-directional switch delivers 5-levels and 7-levels in symmetrical and asymmetrical configurations, respectively. The redundant states in the inverter are used to isolate the faulty switch. In symmetrical configuration, the output levels fall from 5-levels to 3-levels for an open-circuit fault in any uni-directional switch of the inverter. The output levels remain unaffected for an open-circuit fault in bi-directional switch of the inverter. A hardware setup is developed to validate the performance of the proposed inverter with simulations performed in MATLAB/SIMULINK.