Automated grid expansion planning in the distribution network

Project state
Zentral im Bild steht eine Windenergieanlage auf einem Feld, links und rechts eingerahmt von Hochspannungsleitungen.
Increasing feed-in from wind turbines leads to new demands on the grid. Photo: Uwe Schlick /

The power grid is no longer a one-way street. The expansion of photovoltaic systems and wind turbines and other controlled decentralised systems for electricity generation, storage and use make for new tasks that distribution network must carry out: they must not only distribute electricity, but integrate it as coming from decentralised systems.

Active and reactive power control of decentralised systems, and network resources that are easier to control, open up new possibilities for grid operational management. Voltage stability is of particular importance. It is a key factor in the expansion of rural low and medium-voltage grids. Other bottlenecks arise when, within the voltage limits, the current flowing through the network resources is too high. They heat up excessively and can be destroyed. The goal of ANaPlan ('Automated grid expansion planning in the distribution network, smart, innovative and integrated') is to consider grid changes from a macroeconomic perspective, including medium and long-term expansion plans for distributed generation units.

In addition to the investment costs (CAPEX), operational costs (OPEX) should also be considered. The researchers are developing a method with which they can automatically simulate grid expansion or grid conversion in different variants and thereby analyse them. Technical and economic factors play a role here. The goal is to establish forward-looking grid planning. This way, grid expansion and grid operation costs are minimised.

Technical and economic optimisation of grids

Das Vorgehensmodell zur automatisierten Netzausbauplanung ist in der Grafik dargestellt.
Process model of automated grid expansion planning | Graphic: Fraunhofer IWES

Suitable grid data, including ageing data, are initially integrated into a computational model. The scenario framework and the different variants and measures to expand the grid are adapted accordingly. In the following, the optimisation algorithm will be improved and tested. While that is happening, an asset simulation will be started and connected to the grid expansion optimiser. Once the entire simulation has run, the scientists can determine how the results could be ported to other grids and make recommendations for action.

The plan is to produce first results in the form of grid simulations of grid expansion plans by the end of 2016. The project participants expect a first overall result for automated grid expansion planning including asset simulation by mid-2017.

The tasks of the project partners

Researchers at the University of Kassel are fundamentally developing the optimisation algorithm. RWE are providing the necessary data, and are supporting the University of Kassel in the preparation, evaluation and analysis of results. The Fraunhofer Institute for Wind Energy and Energy System Technology IWES are bringing together the individual components and are developing an asset simulation specifically designed for this purpose.

Project duration

01/2016 – 12/2017


Dr. rer. nat. Tanja Kneiske
Fraunhofer-Institut für Windenergie und Energiesystemtechnik IWES
Königstor 59
34119 Kassel
+49(0) 561 7294 136
+49(0) 561 7294 200

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