Experimental Validation of a Quasi-Z-Source Modular Multilevel Converter With DC-Fault Blocking Capability

This article considers the design methodology and modulation of quasi-Z-source modular multilevel converter (qZS-MMC) with half-bridge submodules (HBSMs) evaluates its performance in voltage boosting mode for medium applications. The qZS-MMC consists two qZS networks inserted between terminals dc input source dc-link an MMC, which allows generation output larger than voltage. Two schemes have been analyzed based on a mathematical derivation internal voltages, currents, stored energy. circuit is proven to provide HBSMs deal faults. experimental results validate proposed dc-fault blocking capability MMC. Finally, losses are compared against standard MMC using full-bridge that can also capability. range more efficient has identified. Furthermore, significant reduction number semiconductor power devices same performance.