Modular multi-level DC-DC converter for high-power and high-voltage applications

摘要

A transformer-less DC-DC Modular Multi-levelConverter (DC-DC-MMC) topology based on H-bridge cells isproposed in this paper. The suggested DC-DC-MMC can beused to either control the power flow in a HVdc grid orinterconnect HVdc lines with different voltage levels. Branchenergy and current control loops are presented as well as acell capacitor voltage balancing strategy. Finally, the operationof the converter is validated by means of PSCAD simulations.Results for the operation of the DC-DC-MMC controlling thepower flow between two HVdc grids with different voltage levelsare presented.