This groundbreaking technology has undergone rigorous testing at the TU Braunschweig’s Institute for Electrical Machines, Traction and Drives (IMAB) and the elenia Institute for High Voltage Technology and Power Systems, in Germany.
The charging system was installed at the INTIS site in Lathen, Emsland, where a test vehicle was adapted for extensive functionality and safety tests in collaboration with Technische Universität Braunschweig.
Ralf Effenberger, Managing Director of INTIS, highlighted the success of the project, stating: “The great potential for technical progress that results from cooperation between science and industry is well known and has been confirmed once again in the LISA4CL project.”
Following these developments, the system was installed at the Automotive Research Centre Niedersachsen (NFF) in Braunschweig and handed over to the Facilities Management of Technische Universität Braunschweig for practical testing on the streets of Braunschweig.
With the commissioning in Braunschweig, the LISA4CL project has entered the inductive field test phase, where the developed charging system will be tested under real-world conditions.
Markus Henke, Director of the IMAB, emphasised the importance of this phase: “The practical field test is a very important part of the project, as it allows us to test our technology in practice for its long-term function and benefits for the user.”
The technology
An inductive charging system comprises two primary components: a road-side and a vehicle-side unit.
Energy is transferred wirelessly from the road surface to the parked vehicle through an air gap using magnetic coils.
Inside the car, the electrical energy is conveyed to the high-voltage battery via power electronic circuits.
Achieving high efficiency in wireless charging is crucial for maintaining competitiveness with wired charging systems.
Accordingly, the LISA4CL project has focused intensely on enhancing the efficiency of both the individual components and the entire system.
Tim-Hendrik Dietrich, a research associate at the Institute for Electrical Machines, Traction and Drives at TU Braunschweig, remarked: “To achieve a high overall efficiency, both the individual components and the entire efficiency chain have to be optimised.”
Moreover, the communication between the electric vehicle and the charging station is pivotal.
Gian-Luca Di Modica, a research associate at the elenia Institute at TU Braunschweig, noted: “The implementation of the requirements of the technical standards now available for charging communication in inductive charging is a central building block for the implementation of the technology.”
A key aspect of the project is ensuring interoperability, enabling vehicles to charge at any inductive charging station, regardless of the manufacturer.
This necessitates the development of standards and norms for inductive charging, defining the requirements for contactless energy transfer and communication between the vehicle and the charging station.
The project also supports the standardisation of the 22 kilowatts (kW) power class.
Dr. Ralf Effenberger explained: “We will use our findings from the project to formulate recommendations and present them to international standardisation committees.”
Practical testing and evaluation
The inductive charging system is being tested in practice by TU Braunschweig’s Facilities Management team, even beyond the project’s duration.
Key areas of interest include the potential simplification of the operating process through contactless charging technology and the impact on the car’s range through opportunity charging.
Additionally, the effects on the power grid are being studied, particularly as the number of charging points is expected to increase significantly in the future.
A grid analyser integrated on the infrastructure side of the inductive charging system records energy consumption and performance, measuring power quality parameters to identify potential grid impacts.
The evaluation of inductive charging technology, especially in comparison to the conductive one, is a critical aspect of the project.
A field test with a conductive charging infrastructure has already been conducted, with both inductive and conductive charging points connected to a central charging management system.
The comparative results of these field tests will inform the future development of contactless energy transfer systems.
Another significant focus of the LISA4CL research project is the development of advanced charging concepts for electric vehicles, particularly for fleet applications.
The project emphasises generation-oriented charging with renewable energy and grid-oriented charging based on real-time data about the electricity grid, aiming to minimise grid impact.
Professor Bernd Engel, Head of the elenia Institute at TU Braunschweig, stated: “Intelligent charging concepts play a key role in the mobility transition because they enable higher penetration rates of EVs in grids without grid expansion and increase the carbon footprint of EVs through the optimal integration of renewable energies.”
Project funding and partners
The Federal Ministry for Digital and Transport Affairs (BMDV) funded the LISA4CL project for four years with approximately 1.6 million euros until March 2024.
TU Braunschweig received over 1.3 million euros for the project, allocated between the elenia Institute for High Voltage Technology and Power Systems and the Institute for Electrical Machines, Traction and Drives (IMAB).
Associated partners included INTIS GmbH, Fairsenden, the Berlin Agency for Electromobility eMO, and VW Nutzfahrzeuge.
The implementation of the funding guideline was coordinated by NOW GmbH (National Organisation Hydrogen and Fuel Cell Technology), with PTJ (Projektträger Jülich) acting as the project organiser.
The LISA4CL project exemplifies the promising advancements in inductive charging technology, highlighting the importance of collaboration between science and industry in driving the future of electric vehicle infrastructure.
