Design of series-connected dual-active bridges for integration of wind park cluster into MVDC grids

The transmission of electrical energy with direct current (dc) is a promising alternative to alternating-current (ac) systems. The collection of energy with medium-voltage dc (MVDC) grids also increases the efficiency. In this paper, a dual-active bridge (DAB) dc-dc converter system for integrating wind turbines (WT) into MVDC grids is presented. Within this approach, the secondary-side bridges are series connected whereas the primary-side bridges are not connected with each other. This provides galvanic isolation between the WT.