Faults Diagnosis For Multilevel-Multicell Converters Using Sliding Mode Controller And Adaptive Threshold

Recently, multilevel-multicell converters have been found in Several industrial applications and renewable energy systems. These converters possess the capability to generate multiple voltage levels, thereby mitigating voltage constraints across all their power switches. Ensuring the reliability of these converters remains a significant challenge. Fault diagnosis and reliability analysis play pivotal roles for preventing damage and reducing maintenance costs. This study concentrates on examining the operational behavior of multilevel-multicell converters under both normal and faulty conditions, with a specific emphasis on diagnosing open circuit and short circuit faults appearing in the converter switches. The research is divided into two parts: the first part delves into the aspects of converter control, encompassing open-loop control and closed-loop control using sliding mode techniques, ensuring regulated output voltages, output currents and floating capacitors voltages for sustained converter operation. The second part investigates fault diagnosis, analyzing the impact of faulty converters on the overall functionality of the electrical system. The system simulation is implemented and validated through MATLAB/Simulink environment.