Comparison of Quasi-Two-Level Operation of a Flying Capacitor Converter with Quasi-Two-Level Operation of a Modular Multilevel Converter

Today's medium voltage converters are often multilevel converters. These converters require many large passive components. The new Quasi-Two-Level operating (Q2O) mode is intended to minimize the passive components while preserving the advantages of the multilevel topology as far as possible. This novel operation mode is investigated for the Modular Multilevel Converter (MMC) and the Flying Capacitor Converter (FCC). This paper briefly summarizes and compares the control, modulation and minimization potential of the passive components of the Q20-mode for these two topologies. Thereby, the different topologies are introduced and compared. Finally, the advantages and disadvantages of this new mode of operation in these two topologies are discussed.