The transport sector was responsible for around 19 percent of greenhouse gas emissions in Germany in 2020. Until 2050, these emissions have to be reduced by at least 80 percent. The eHighway project shows how this can work. On the Autobahn 1 between Reinfeld and the Lübeck interchange, a hybrid truck has been on a test track several times a day since January 2020. The trailer-truck, which is equipped with a diesel engine and electric motor, is connected to the overhead line via a pantograph. This trolley system is part of a research project at Kiel University of Applied Sciences, in which the electrification of heavy commercial vehicles is to be tested in practice. The 2 x 5 kilometer test track on the A1 is one of a total of three in Germany. Further hybrid vehicles will be included in the test phase soon and they will run until the end of 2022. The field trial is intended to show what opportunities and risks are associated with electrification. The aim is to establish an almost loss-free, direct energy supply for the vehicles via overhead lines and to provide both the energy for traction and charging current from renewable energy sources. The vehicle batteries can be charged while the vehicle is on the move, enabling it to cover routes that have not yet been extended with overhead lines. Practical operation is accompanied by comprehensive scientific studies.
FREQCON know-how in demand
On behalf of the university of applied sciences, we developed and built a so-called traction substation for supplying power to the overhead line from the medium-voltage grid. This system will serve as an extension of an already installed system, meeting the latest technical requirements. In particular, the grid compatibility of the system was optimized in order to support the grid voltage with reactive power. In addition, this enables bidirectional operation: The energy released when the truck brakes can be recuperated and fed into the power grid. Due to these requirements, FREQCON’s converters have certification according to VDE AR 4110.
Multi-talented MSC converter
For grid stabilization and energy supply, a system expansion with battery storage is planned as a next step. This can significantly increase the distance between the necessary connection points to the public grid and reduce the number of grid interconnection points. Thanks to the flexibility of our MSC converter, additional energy storage systems as well as renewable energy sources, such as wind turbines or photovoltaic systems, can be integrated directly via a DC bus and with a high degree of efficiency. Even the integration of an electrolyzer is possible with little effort. The DC interfaces used here work bidirectionally, so that DC consumers, such as the electrolyzer, can be supplied at the same time and vehicle charging stations can be connected directly via the DC interface. With this system, the overhead line used to supply the trucks can be used simultaneously for an exchange of generators, consumers and storage units without burdening the public grid infrastructure. In this sense, this system has enormous significance in the transport sector for the energy transition and for achieving emission targets.