Charging cars in a swarm

25.07.2025

Source: E & M powernews

A new approach to charge control aims to prevent grid overloads even without grid expansion or complex measurement technology.

Using several hundred meters of cable and six simulated households, researchers from the Cologne Institute for Renewable Energy (CIRE) at the Faculty of Information, Media and Electrical Engineering at TH Köln have tested a solution developed in-house for communicating charging stations. In the "GridMaximiser" project, an algorithm controls the optimal utilization based on grid status data and also takes into account the charging preferences of the users, as the university has now announced.

"If many households in a residential area purchase an electric car, charging the vehicles can lead to challenges for the stability of the power grid," says project manager Prof. Dr. Eberhard Waffenschmidt from CIRE. To prevent an overload, there are two complex options: Firstly, the cost-intensive and lengthy grid expansion and secondly, equipping buildings with complex measurement technology. "We are pursuing a simpler way to coordinate the charging processes with each other and control them in a way that serves the grid. Our solution is based on the swarm principle."

The application developed collects measurement data from charging stations already present in the buildings and can determine the current grid status on this basis. This should enable charging processes to be controlled in such a way that the distribution grids are not overloaded and the permitted voltage bands, i.e. the upper and lower voltage limits, are not exceeded or undershot.

Independent management of the charging infrastructure

"Our solution does not require a connection to the grid operator's control room," explains the second project manager, Prof. Dr. Ingo Stadler from CIRE. An additional control unit to distribute the available charging power is also not required. "We rely on a charging infrastructure that manages itself independently after installation, without a central authority taking over control. This means less effort for planning and coordination."
To plan the charging processes, the algorithm first determines the grid status and uses measurement data such as the electrical voltage and current strength as well as standard load profiles to determine the aggregated power consumption of appliances such as ovens or washing machines within a household. Based on this, the program then allocates free grid capacity to e-cars to be charged, taking into account the charging preferences of car users.

According to the researchers, the application has already been patented in the USA and is still being examined in the EU. In a follow-up project, the application tested in the laboratory is now to be expanded to include an energy management system in order to incorporate other controllable electricity consumers such as heat pumps. A real-life test with a grid operator is also planned.

The "GridMaximiser" project ran for 18 months. The state of North Rhine-Westphalia and the European Regional Development Fund (ERDF) supported the project with over 800,000 euros.

Author: Katia Meyer-Tien