Flexibility of grid planning in medium-voltage hybrid AC/DC distribution grids

The consequences of the energy system transformation are causing a far-reaching change in the electricity supply system. In particular, the function of medium-voltage (MV) networks has changed: In addition to distributing energy from the high-voltage level to the low-voltage level, MV networks also integrate the energy from renewable energy sources. Therefore, grid expansion plays a central role in meeting infrastructural challenges. A possible solution is the integration of direct current (DC) technologies into the distribution grid. DC lines can enable higher energy transport and provide flexibility in the form of reactive power for voltage stability. Hence, this study describes a method for optimising the integration of DC power lines into MV networks. Exemplary results show the influence of decreasing converter costs on the usage of DC technology in the grid planning process.