Influences of Direct Currents on Power Transformers Caused by AC- HVDC Interactions in Hybrid Grids

The implementation of HVDC systems into the German grid is an essential aspect in the transition from conventional coal and nuclear power to renewable sources. The country's large wind farms in the North of Germany could provide a significant share of electrical power. The main consumption is located in the middle and South. Considering given distances and required additional transmission capacities several studies have shown the need of HVDC corridors from North to South. Nevertheless, the installation of new overhead lines is a sensitive issue in public perception. E.g. the changes in the landscape that come along grid expansion are widely rejected. Therefore, alternatives are considered to improve transmission capacities without the installation of additional line systems. One option is…