DC-side fault current management in extended multiterminal-HVDC-grids

Abstract

The global need for reliable and efficient energy supplies and the necessary shift from fossil fuels to regenerative sources imposes great challenges for improved electric power transmission. Extended HVDC-SuperGrids, covering large areas and distances, are considered to lead to very attractive solutions. While recent progress of power electronics has enabled suitable and extremely efficient converters, the best structure of a large DC-grid and the remaining other key components are still under investigation. This paper focuses on main problems, especially handling of fault currents or DC-short circuits in the grid. The interaction of the key components - Modular Multilevel Converters and DC-circuit breakers - is investigated.