Charging on electric overhead lines


In the DC-LEO project, a direct current charging infrastructure (DC-LIS) is to be developed that accesses the overhead line network of trams. In the course of the market ramp-up of electromobility, the efficient use of already existing electrical network structures is of particular importance in order to reduce costs for infrastructure expansion. Furthermore, an extended expansion of power capacities of overhead line networks could be made significantly more cost-efficient compared to the new installation of underground cables, especially in inner-city areas.

The project is funded by the Federal Ministry for Economic Affairs and Energy as part of the technology competition “ICT for electromobility: intelligent applications for mobility, logistics and energy”.

You can find out more about the further progress of the project here.


InTraSol - Intelligent Traffic Solutions GmbH (consortium leader)

In the joint project, InTraSol takes on the role of consortium leader and is the interface between the practical partners on site in Nordhausen and the participating research institutes. InTraSol acts as consortium leader because the company owns the utility model “Energy distribution arrangement and charging station for an electric vehicle” (No.20 2017 104 077). In addition, as consortium leader, the SME is in charge of project and information management.


Stadtwerke Nordhausen - Holding for Supply and Transport GmbH

Stadtwerke Nordhausen is contributing its expertise regarding its tram network to the project. As an application area, the city of Nordhausen is indispensable for testing the prototype. In the area of location and environment analysis, Stadtwerke Nordhausen is working closely with FH Erfurt.


DLR Institute for Networked Energy Systems e.V.

In DC-LEO, the DLR-VE from Oldenburg is in charge of field measurements and laboratory tests to ensure the technical feasibility of the demonstrator. In close cooperation with SWN, DLR-VE is installing monitoring units in the model region to analyse the real current/voltage behaviour at suitable grid connection points for the subsequent connection of charging columns to the overhead DC grid. Based on the transfer of the identified grid profiles to the DLR grid laboratory, the DLR-VE provides suitable development environments for the two partners InTraSol and SEN.



German Aerospace Center e.V. - Institute of Transportation Systems Engineering

In the joint project, DLR-TS from Braunschewig is responsible for stakeholder-oriented research, the analysis of the joint project from the user’s point of view and the implementation of multiplier activities in order to make the project results accessible to a broad public. In doing so, DLR-TS builds on the results of the other joint project partners and provides scientifically collected findings on the user perspective, which are published by InTraSol in the joint project’s action guide.



Erfurt University of Applied Sciences

In the DC-LEO project, the University of Applied Sciences Erfurt (Prof. Dr. Wolfgang Rid, Chair of Urban and Regional Economics) is responsible for the scientific evaluation, in the context of which results are generated with the help of a scenario analysis, which can be adapted to different municipal and operational framework conditions and prepared in a practical way in the form of a guide for action. In addition, the development of transfer tools is being sought. The UAS Erfurt is also supporting the DLR-VE in the requirements analysis with its urban planning expertise and the business model development in the concept development of InTraSol with its economic expertise.



SEN - System Entwicklung Nordhausen GmbH

SEN – System Entwicklung Nordhausen GmbH is primarily responsible for building the hardware and developing the software for the prototype and the communication interface.




The aim of the project is not only the technological development of the DC-LIS, but also its testing in an urban test field in Nordhausen (Thuringia). In the course of the project, the following four use-cases will be examined in more detail:


  1. Charging of eBuses in bus depots (overnight charging at the depot)
  2. Charging of eBuses in circulating traffic for large buses or also as a ridepooling concept
  3. Charging of e-vehicles at Park&Ride car parks
  4. Charging of e-vehicles by private occasional chargers in public spaces


A DC charging station (LEO-LIS) is to be developed as a new product:


  • can be connected to any DC (overhead) line
  • complies with safety standards and norms
  • which combine the common DC charging standards (CCS, CHAdeMO) with the current
  • Operate communication protocols (IEC 61851 and ISO 15118)
  • is equipped with an identification procedure and billing system
  • can map different business models (at one location)
  • is equipped with V2X to share information between vehicle and infrastructure
  • represents an important building block for increasing sustainability in public transport.


The Nordhausen Tramway Network

The Nordhausen tramway is celebrating its 120th anniversary in the year of the project launch and will take a further step towards transport and energy transition as part of this project. Back in 2000, the Nordhausen tramway celebrated a world premiere with its 100th anniversary with the introduction of the “Combino Duo” dual-power locomotive specially developed by Siemens for operation on sections of the Harzer Schmalspurbahnen GmbH line without overhead lines. The tram network in Nordhausen is divided into three lines on which, in addition to three historic railcars for special purposes, nine Combino vehicles (Siemens) operate.


  • Linie 1 = 3,22 km Bahnhofsplatz – Südharz Klinikum
  • Linie 2 = 4,55 km Nordhausen/Ost – Parkallee
  • as well as the overhead line-free line line 10 = 11.0 km Nordhausen/Bahnhofsplatz – Ilfeld/Neanderklinik on which the three hybrid vehicles of the Combino-Duo series (Siemens) with a diesel engine generator set (diesel hybrid drive – DHA), which provides the necessary electrical energy in the area of the non-electrified line sections, operate.


In total, there is an electrified overhead line network of 7.8 km in the project area with a substation and over 350 points for taps for the installation of overhead line-supplied charging facilities for electric vehicles. The overhead line network has a nominal voltage of 600 V in the standard supply, voltage peaks of up to 800 V are possible and the track gauge is 1000 mm.

Our company is certified according to DIN EN ISO 9001:2015.


InTraSol – Intelligent Traffic Solutions GmbH
Rothenburgstraße 17
99734 Nordhausen