Comparison of the most efficient DC-DC converters for power conversion in HVDC grids

The structure of electric energy generation is rapidly changing, from controllable and equally distributed power generation using few high power plants to a decentralized and volatile power generation with many, widely distributed, small and medium power plants. Especially the volatile nature of regenerative energy sources demands a strong power grid, capable of flexible, long distance power transportation. The key technology for the future of the power grid is high voltage direct current (HVDC) power transmission, which in the next years will move from the periphery of the AC grid to its center. One of the key components of a future HVDC grid are efficient HVDC-DC power converters allowing the use of distinct voltage levels for the collection, long distance transmission and distribution of electric energy. In this paper two promising HVDC-DC converter topologies will be compared in terms of efficiency and investment costs.