MMC-Based High Power DC-DC Converter Employing Scott Transformer

HVDC transmission, along with MVDC distribution grids, have been gaining more and more attention lately. With the aim of obtaining resilient and flexible DC grid, reliable means for interfacing two of its parts operating under different voltage levels must be ensured. This paper proposes bidirectional, isolated, high step-down, MMC-based, DC-DC converter intended to connect high/medium voltage bipolar DC grid and low voltage DC grid. In order to achieve galvanic separation between two converter stages, Scott transformer connection was used.