A robust seven-level fault tolerant hybrid cascaded H-bridge inverter

The most commonly used inverters for renewable energy applications are cascaded H-bridge (CHB) inverters. Fault tolerance is required for semi-conductor switches and DC supplies to safe guard the system under fault conditions for continuous operation. A novel seven-level hybrid CHB inverter with fault tolerance is introduced through the incorporation of a reduced switch seven-level boost (RSSLB) inverter module in conjunction with the H-bridge modules. This inverter configuration guarantees uninterrupted operation even in the presence of faults. Alongside its fault-tolerant features, the RSSLB module within the proposed system facilitates a voltage boost of three and ensures self-balancing of the switched capacitors with its implemented control scheme. Extensive simulation results under various operating scenarios validate the concept of the unique fault-tolerant inverter topology that has been developed. The proposed configuration is validated by the experimental findings by the prototype system developed in the lab.