Modular Megawatt-range Wireless EV Charging Infrastructure Providing Smart Grid Services

Electric vehicles are rapidly populating Norwegian roads, with unquestioned beneficial effects on both energy efficiency and air pollution. However, as new vehicles come equipped with ever bigger on-board batteries, the issue of developing suitable charging infrastructures must be addressed. In particular, simultaneous quick charging of many batteries poses serious challenges to the existing electric grid, calling for new methods that can mitigate such effects without needing major redesigning or expensive upgrades to the existing electrical distribution system. MoMeWEC aims at developing a new way of building very large scale parking infrastructures, where hundreds of vehicles can possibly be charged simultaneously with minimized impact on the grid and with reduced cost and footprint of the installation. A combination of modern wireless charging technology with the latest advances in modular electric power converter design is proposed in MoMeWEC and investigated throughout the project. Analytical calculations, numerical simulations and lab-scale testing are used to show the feasibility of the proposed approach, as well as the expected savings it will bring. Great effort has been put into establishing research links between the institutions involved in the project (Sintef Energi, The University of Tokyo, Nagaoka University of Technology, RWTH Aachen), coming from three different countries. The cooperative research effort has resulted in the development of a new large-scale parking concept, with several scientific advances that have been published in renowned peer-reviewed journals, besides being presented in several relevant International conferences. A reduced-scale demonstrator of the concept has been built in Sintef premises, with the help of visiting students from Japan. The demonstrator includes a small-scale wireless charging system and a complete parking layout emulator with 72 spots for EVs. The system is connected to a real-time simulation platform that makes possible to emulate novel parking management strategies that have been devised by the project partners. Before the COVID19 crisis, The project had already seen significant researchers' mobility, both of senior and junior personnel, with a good mix of short, medium and long term stays in all participating countries. The 2019 annual Workshops with participation of all partners was organized in Tokyo University premises with the intended participation of world-leading scientists success but had to be cancelled few days before the intended date due to the international travel bans. Since March 2020, the activity has been hampered by the impossibility of implementing research exchanges, and most of the interactions between research groups has taken place remotely. Fortunately, joint experiments could be carried out that allowed for publication of key results. From November 2021, limited research exchanges have been resumed to maximize the impact of the project. A closing workshop covering the aspects related to large-scale parking infrastructures and related grid services has been organized by the MoMeWEC consortium within the IEEE-sponsored conference SmartGridComm, October 2021, Aachen, Germany. Overall, the project has been successful in advancing cooperation between the three participating countries, in spite of the difficulties related to the COVID crisis. It can be said that all the intended scientific goals have been reached and that progress has been made in methodologies for planning and operation of large-scale EV parking and charging infrastructures.

The project has successfully achieved all the intended objectives, both in terms of scientific outcome and in terms of strengthened international cooperation. A novel EV parking-and-charging concept based on modular converter design has been proposed and investigated thoroughly. The potential savings associated to the proposed topology have been quantified, showing that the cost associated to transformers can be eliminated, while the amount of copper required for cabling can be reduced by 93%. Nine peer-reviewed joint publications have been produced within the project, of which three have been published in renowned journals. Additional publications have been produced by the partners independently. The project has facilitated considerable researchers mobility, contributing to the improvement of international cooperation between Norway-Japan-Germany with the creation of long-lasting links.

Electrification of urban transport has been identified as a key enabling technology for achieving a sustainable low carbon society. Battery technology is rapidly improving and EVs with remarkable range are starting to appear at affordable price. Unfortunately, high capacity batteries need powerful chargers to be replenished in short time, already imposing new and emerging challenges to low voltage distribution grids. The problem is expected to become even more pronounced in urban parking areas, where many high-power batteries must be charged simultaneously, resulting in complex, bulky and expensive electrical installations. Likewise, equipping all parking slots of a large residential building with powerful charging facilities may prove impractical or even impossible due to space constraints or limitations of the local grid. This project aims at developing innovative solutions for high-power charging stations with minimum footprint and maximum flexibility, by combining the recent advances in modular converter technology, wireless inductive charging and advanced grid connection techniques for providing smart vehicle-to-grid (V2G) or vehicle-to-home (V2H) services. Throughout the project, international cooperation is fostered by encouraging mobility of senior as well as junior researchers and students. Funding is provided for long-term research periods, in an attempt to optimize the use of existing unique laboratory infrastructures and to facilitate the exchange of knowledge in complementary fields. The project is related to the area of "Electromobility and challengers for the power system", covering key aspects as "development of new components", "efficient operation of electricity grids" and "demonstration and assessment of new technologies", as specified in the call text.