A flywheel is undergoing trials at IFSTTAR’s Satory site

Prototype energy converter made by the TEMA team at IFSTTAR in order to power the flywheel. © Ifsttar - laboratoire SATIE/TEMA

In the framework of the VIVE collaborative project, the bunker at IFSTTAR’s Versailles-Satory site is being used to house a prototype flywheel. This new scientific device will soon be ready for testing, its intended application being the rapid recharging of electric vehicles.

More effective, more responsive, more robust, more compact… This is what is promised by the flywheel that is currently being installed in the bunker at IFSTTAR’s Versailles-Satory site. Since July 2017, this test laboratory has been home to a new high speed energy storage and release device. This equipment plays a central role in the VIVE project whose name is the French acronym for flywheel for recharging electric vehicles. The project is managed by AER Atmostat and receives more than 4 million euros of funding from the FUI (the Single Interdepartmental Fund). VIVE is collaborative, bringing in a large number of additional industrial and scientific players ─ Vinci, le CEA, INERIS, the firms Controlsys Engineering and DBT as well as IFSTTAR.

The prototype flywheel in its test environment in the bunker at IFSTTAR’s Versailles-Satory site. © Ifsttar - Laboratoire SATIE/TEMA - AER Atmostat

 Energy storage devices take a number of different forms, for example electrochemical batteries, supercondensers and electromagnetic coils. Flywheels are of interest for two main reasons: “They can provide the required energy rapidly and need little maintenance” according to Alexandre De Bernardinis, a researcher in IFSTTAR’s Components and Systems Laboratory (COSYS). “A flywheel can be subjected to hundreds of thousands of charging and discharging cycles without heating and can also be placed in a vacuum” adds this expert in system energetics and electrical interfaces. The prototype which is currently being installed aims to develop an innovative rapid recharging technique for electric vehicles with a limited impact on the network: “This device will help us to partially recharge electric vehicles in ten minutes and take pressure off the electricity network when energy production is intermittent.” As part of the SATIE/TEMA team, Alexandre De Bernardinis is particularly involved in two of the projects main goals, namely building the flywheel’s electricity supply and installing it in the bunker.

Innovative technology using silicon carbide semiconductors

“Like a potter’s wheel, the flywheel is a rotating mass that can store and deliver energy” the researcher sums up. “We drive a steel wheel at a certain speed in order to store kinetic energy. The prototype we are working with rotates at between 3,000 and 6,000 rpm and has a power output of 50kW over this speed range. The novelty of this model lies in its design, in particular the materials – the inertia wheel is made of steel – and the electrical interfaces”. AER Atmostat is building the mechanical part of the device. The SATIE/TEMA team at IFSTTAR is responsible for the electricals: “We have developed a high efficiency converter based on innovative silicon carbide semiconductor technology” Alexandre De Bernardinis explains. “Our research should enable us to limit energy losses during operation, reach high frequencies and develop a compact cooling system.’

Today what needs to be done is to complete assembly of the flywheel with its electrical interface and control system before testing it in use, i.e. connected to an electric vehicle recharging point. These operating tests are scheduled for the first half of 2018. “This is a scientific and technological challenge” the researcher enthusiastically remarks. “We can’t wait to see the flywheel’s real potential and our converter’s energy efficiency.” The results should be available before the end of the year.