Our power systems consist of various voltage levels from very high to low voltage. Generally, lower voltages are safer and easier to handle, but higher voltages reduce the transmission losses. The low voltage (230–400 V), medium voltage (6–40 kV), and in some power systems also the high voltage (up to 110 kV) levels constitute the distribution network; higher voltage levels belong to the transmission network. Transformers connect the different voltage levels.

Renewable power plants change the task of the distribution networks

Traditionally, the distribution networks distribute power to the consumers, while the generation units (power plants) feed their energy into the transmission network. Since power plants based on renewable energies often have lower capacities compared to conventional power plants, they are mostly connected to the distribution networks. Due to those changes, new challenges for the distribution networks arise.

Network extension and intelligent grid control are solutions to changing conditions

Distribution networks connecting significant amounts of power generation can be prone to equipment overloading, and to violations of the permissible voltage range. Changes in weather conditions lead to fluctuations of the distribution networks’ power balance, which can lead to a less stable system. Those issues can be overcome with grid upgrades. A new solution is to use intelligent control algorithms and a communication infrastructure, transforming the network into a smart grid.

In either case, experienced experts are able to check all measures for technical applicability and cost-efficiency by means of simulations.