Green Access

Intelligent distribution grids ensure improved integration of renewable energy sources

Project state
first results
Da sich die einzelnen Spannungsebenen beeinflussen, arbeiten die Entwickler im Forschungsvorhaben Green Access Netzebenenübergreifend.
Because the individual voltage levels influence one another, the developers in the Green Access research project are taking into account all the grid levels. © mariusz szczygiel -

In the joint Green Access project, the developers are working on facilitating the cost-effective and efficient operation of distribution grids. They are focussing on creating an intelligent distribution grid. This is intended to function according to a so-called plug & automate principle and thus help to create a future-proof, stable and reliable distribution grid. The researchers are primarily working on improving the adaptive monitoring and control algorithms, intelligent control systems and a grid-friendly infrastructure. The scientists are aiming to design the grid so that it can independently adapt itself to future load and infeed changes and varying grid topologies.

In the Green Access project, the engineers are investigating the low- and medium-voltage level as a whole. The project partners believe that this is essential because the voltage levels and thus the control concepts at the low- and medium-voltage level mutually influence one another. In addition, there are joint operating limits such as for the voltage stability. Isolated consideration of the levels could therefore lead to inaccurate assessments and findings in terms of the potential for intelligently automating the distribution grid. The scientists are investigating more than just one voltage level, which will therefore enable them to achieve greater grid adaptability. They are researching how Green Access can enable a functional, stable and reliable overall system. In addition to the theoretical considerations, the project will also include field trials that will be used for verifying the calculations and simulations.

The research focus areas at a glance

  • Adaptive distribution grid automation: Development and testing of adaptive local monitoring and control of the distribution grid. This control must be able to reconfigure itself independently, for example with changes to the topology, suppliers or loads, and take into account central requirements.
  • IT coordination of the requirements: Development of a concept for a central control centre for processing and storing global data in terms of an energy information network and establishing the framework for automating the distribution grid.
  • Grid-friendly infrastructure: A grid-friendly and standards-based infrastructure will be used to combine levels such as the IT coordination with the grid operators, the decentralised control units in each grid section and controllable end-devices (such as inverters).

Smart grid – the intelligent power grid

© chombosan -

In a smart grid, the electricity consumers and producers work together. For this purpose they are interconnected using modern information and communications technology (ICT) and can mutually influence one other. When there are large amounts of energy available, large loads can be switched on; when there is a lower demand these loads can be taken offline without sacrificing comfort. A simple example: A cold store must have a maximum temperature of seven degrees Celsius. When the power supply exceeds demand when there are strong winds and clear skies, the temperature can also be cooled down to between three and five degrees Celsius. If clouds then draw over, the cold store only needs energy again when the temperature has reached its maximum. In a smart grid, the electricity price can also be flexible, so that in addition to the technical benefits there are also economic advantages for the operators of intelligent loads.

Further details on smart grids can be found in "Basic information".

With this joint project, the consortium from Green Access is identifying alternative solutions that enable technically and economically efficient network infrastructures without requiring an extensive, nationwide expansion of the grid. Through intelligent monitoring of the distribution grid and by researching adaptive control concepts, Green Access is creating the basis for a cost-effective transformation and development of the energy supply in which new smart grid solutions will contribute to the increased integration of renewable energy, improved grid reliability and a reduction in investment costs. Through the use of intelligent and adaptive distribution grid automation, the current grids will be prepared today for the challenges of tomorrow. Green Access is thus making an important contribution to further developing the economic, environmental and technical advantages of the smart grid.

At the start of the project, the participants have analysed the current grid conditions and have begun creating scenarios relevant to the project with regard to future expansion developments. They have also begun to develop quantitative indicators with which they will later evaluate their results and compare them with other projects. During the course of the project they will develop systems and solutions for the adaptive automation of the distribution grid. These will include, for example, medium- and low-voltage controllers, a smart grid control system and the coordination of interfaces and protocols used for the information and communications technology (ICT). Green Access is further developing already existing solutions such as intelligent local grid stations or controllable inverters into an adaptive distribution grid automation system and will test the new system in a one-year field trial. The results of the field trial are expected in the third part of the project.

The tasks of the project partners in detail:

Project duration

01/2015 - 12/2018


Dr.-Ing. Thomas Kumm
Project coordinator
Cloppenburger Straße 302
26133 Oldenburg
+49 441 4808-2112
+49 441 4808-1395

additional recommendations

Simulated grid voltage stabilisation

22.02.2016 – More power leads to a higher voltage. Green Access investigates control schemes to comply with the voltage range during good weather conditions.


Basic information

How is our power grid structured? What sort of networks are there? What do security and quality of supply mean?


What do direct and alternating current mean? How do they differ and what are the advantages and disadvantages?


Virtual power plants, active distribution grids, smart meters and adaptive protection systems – here you can find information about the most important aspects of smart grids.


The energy generated in a grid must always be equal to the energy consumed. The ancillary services are tasked with ensuring this.