Benefit of a HVDC Back-to-Back Station in a Real Distribution Grid

Technological progress in the field of power electronics enables DC applications in distribution grids to improve grid operation and enhance power flow control. One of several options is the implementation of DC back-to-back stations in HV grids as a first step towards a more flexible grid. In cooperation with a German DSO, this paper presents results of computer-assisted simulations regarding the implementation of a DC back-to-back station in a real 110-kV HV grid. The benefit of the implementation is assessed for two relevant use cases: First, the possibility to relieve the overlaying transmission grid by minimizing the power exchange with the HV grid. And second, the reduction of grid expansion measures by better exploiting unused hosting capacities. The results show that a DC back-to-back station might be beneficial depending on converter prices and the development of the supply task for the latter case.