Modelling, simulation and analysis of a Modular Multilevel Converter for medium voltage applications

摘要

The Modular Multilevel Converter (M2C) is an emerging multilevel converter for HVDC and FACTS as well as for future AC-fed traction vehicles or medium voltage drives (MVD). A suitable converter model of the Modular Multilevel Converter (M2C) is presented. A 7.2 kV, 7.5 MVA converter is taken as an example to analyze characteristic waveforms of the converter. The cause of the circulating currents — a phenomenon unique to this topology — is investigated. Furthermore, particular attention is paid to the current distribution in the converter cells for characteristic load phase angles.