Inductive charging station in use at the Automotive Research Centre Niedersachsen (NFF)
Inductive charging of electric vehicles is an innovative charging technology that enables a convenient, wireless charging experience. In addition to increased safety due to the absence of visible cables, it offers huge potential in terms of automating charging processes. Together with partners, the Technical University of Braunschweig has created a stationary inductive charging system and tested it extensively. The system was installed at NFF. It is used by the building management of TU Braunschweig, having integrated inductive charging into its operating procedures.
In the LISA4CL research project, two institutes at TU Braunschweig and INTIS GmbH developed a stationary inductive charging system for electric vehicles that has a charging output of 22 kW. At the elenia Institute for High Voltage Technology and Power Systems and at the Institute for Electric Machines, Traction and Drives (IMAB) at TU Braunschweig, component tests were conducted for the inductive charging technology. The inductive charging system was built at INTIS GmbH and a test vehicle was modified in the light vehicle class. Then the entire system was extensively tested in cooperation with TU Braunschweig in preparation for field tests. This included both system function as well as safety tests to ensure suitability for practical use.
The Federal Ministry for Digital and Transport (BMDV) funded the LISA4CL project under the electric mobility funding guideline for four years in the amount of around 1.6 million euros until March of 2024. TU Braunschweig received over 1.3 million euros, distributed between the elenia Institute for High Voltage Technology and Power Systems and the Institute for Electric Machines, Traction and Drives (IMAB). As well as INTIS GmbH as project partner, Fairsenden, the Berlin Agency for Electromobility emo and VW Commercial Vehicles were associated partners. Project Management Jülich (PtJ) acted as the project management organisation. The implementation of the funding guideline was supported by NOW GmbH (National Organisation Hydrogen and Fuel Cell Technology).
Daniela Kluckert, Parliamentary State Secretary at the Federal Ministry for Digital and Transport: “The research and development project LISA4CL opens up the possibility of using wireless charging for electric vehicles in city logistics, as has become daily practice for mobile phones. In terms of accessibility, inductive charging promises to make life considerably easier, because it makes it much simpler to access charging infrastructure. The BMDV supports the transfer of technology and innovation to accelerate the decarbonization of the transport sector and at the same time, support the competitiveness of Germany as an business location. Funding LISA4CL is part of those efforts.”
Professor Bernd Engel, Head of the elenia Institute at TU Braunschweig: “Intelligent charging concepts are essential for the grid and system integration of electric vehicles. They enable an ecological as well as an economically optimized operation of electric vehicle fleets.”
In the field test phase, the inductive charging system first came into use at Fairsenden in Berlin in inner city logistics. A field test was already underway at Fairsenden with conducting charging points for a practical comparison with wired charging infrastructure. In the last phase of the project, the inductive charging technology was installed at the Automotive Research Centre Niedersachsen (NFF) in Braunschweig. The building management at TU Braunschweig is using the prototype vehicle to examine inductive charging in regular practical use. The charging system will be used beyond the end of the project to facilitate long-term testing of inductive charging technology.
The technology: an inductive charging system consists of both a street and a vehicle component. With the aid of magnetic coils, energy is transferred via an air gap contactlessly from the road surface to the parked vehicle. The electric energy is fed into the high-voltage battery via power electric circuits.
Findings from the development and testing of an inductive charging system
- The system efficiency is consistently high for the system developed and is not substantially reduced by inexact parking.
- Light commercial vehicles offer sufficient installation space to allow the integration of efficiency-optimised systems. A space-saving integration of the system is possible in this vehicle class.
- These types of systems must be interoperable for future series use. That is why standardisation committees are currently dealing with inductive charging systems.
Real operation of the inductive charging system in field tests
The field tests demonstrated that inductive charging technology in real operation is technically feasible and functional. Inductive charging was integrated into the respective operational procedures by Fairsenden as well as by the building management at TU Braunschweig. The system was positively evaluated by users. Furthermore, practical use has shown, that the technology requires little maintenance.
The data gathered on the charging processes in the field test in Berlin show that the inductive charging system was used on a daily basis. Charging took place overnight at the end of service as well as interim charging stops spread throughout the day, also known as opportunity charging. The inductive charging technology provides a simple and user-friendly integration of opportunity charging. Charging processes can begin directly from the driver’s seat at the end of a journey. The simplified operation shows the potential of contactless charging with regard to optimizing operational processes.
Project website: www.now-gmbh.de/projektfinder/lisa4cl/
Picture: VW e-Crafter converted for inductive charging approaches the inductive charging pad at NFF. | Picture credits: elenia/TU Braunschweig
Source: TU Braunschweig