A Multiple Fault-tolerant Multilevel Inverter with Hybrid Cascaded H-bridges

Most of the widely used renewable energy sources like PV systems produce DC output and in order to integrate this output with AC grid, an efficient inverter system with fault tolerance is essential. Even for a little period of time, a switch defect in an inverter might have a negative impact on the related essential loads. While considering the several advantages and applications, cascaded multilevel inverter(CHB MLI) can significantly improve system reliability through its fault-tolerant operation due to its switching redundancy. Many multilevel inverters with several control strategies are proposed in literature, but only fewer inverters are with fault tolerant capability. This research suggests a hybrid H-bridge-based CHB MLI architecture that is fault-tolerant. The inverter is capable of operating with rated power under multiple switch open fault conditions. A five-level fault tolerant CHB MLI is simulated and analysed under various fault conditions. Reconfiguration of inverter is possible under input source variations is also possible in this system. The operation of inverter is validated with experimental results. This inverter is suitable for industrial drives, battery energy storage systems and uninterrupted power systems where reliable operation is needed.