Distribution grid interconnection using DC-links

A significant number of renewable energy sources are predominantly connected to the distribution grid level. The ratio of feed-in to load is very different in distribution systems so that the balancing between the grids usually takes place via the transmission grid. Thus, leads to additional bottlenecks in the related grid areas and is associated with curtailment of renewable energy generation. This contribution represents a new approach to power balancing at the distribution system level. The objective is to integrate several point-to-point direct current (DC) links into the distribution system operation so that additional power flow capacities and related ancillary services can be provided.