Medium-voltage DC distribution grids in urban areas

Abstract

The potential of medium-voltage dc (MVDC) grids in various applications has been under investigation by different researchers. In several works, the advantages of implementing MVDC technology into collector grids of wind and photovoltaic (PV) parks are pointed out. The main driver is that the grid-side inverter of the distributed generators as well as lossy grid filters and bulky 50 Hz transformer become obsolete. However, MVDC grids are a promising alternative to established ac grids not only for power generation. Within this work, the advantages regarding system efficiency and investment costs of using MVDC for the distribution of electrical energy is presented. Conventional low-voltage ac-grids and possible medium-voltage ac grids are also analyzed to compare the different implementation approaches.