FEV Battery test center in France

Increased battery test capacity tenfold

The construction of the battery test center in Saint Quentin en Yvelines increases the current capacity tenfold, which has been in place for 7 years. First of all, FEV decided to pay particular attention to cells testing: this is the heart of the battery. The new test center has a testing capacity of 300 cells. Characterization and aging tests are performed on a few cells, whose behavior is extrapolated to the complete battery.  Four "walk in-chambers", as well as two bench packs - one pack corresponding to a complete battery - are used to develop the cooling system and control strategies for the BMS - Battery Management System. The battery benches can then be combined with the nearby electric and conventional power benches (in the case of hybrid vehicles), and vehicle and driver simulation models can be integrated into this set via bench computing: thus the complete vehicle is fully represented, and many hours on the chassis dynamometer or on the road are saved. This test infrastructure is completed by 100v module benches and power electronics benches. As we know, particular attention must be paid to extreme conditions, where the internal chemistry of the battery can get out of hand: FEV also carries out abusive battery tests, such as fire tests, over voltages, or complete discharge of the battery, as well as crash tests.

Validation of the entire powertrain

Another key investment in the FEV system in France is an e-axle bench, which allows the entire traction chain to be tested. Its maximum speed oscillates around 2,500 rpm, for 3000 Nm for torque. The bench is adaptable to many types of architectures. The high programming flexibility of MORPHEE, the FEV automation system, allows specific tests to be carried out, for example to define the control laws of the EMS (Energy Management System). This allows characterization tests to be performed, allowing models to be performed. These models can then be used in the subsequent development stages of the EMS, whether in the case of a hybrid engine on an Engine in the Loop bench or in the case of a purely electric engine on an office or HiL bench: in this case, the electric vehicle is fully modelled. In addition, the thermal management of the electric motor, with derating operations, makes it possible to extend the service life of the electric motors, and contributes to the preservation of the vehicle's autonomy: here too, MORPHEE's capabilities are necessary for the calibration of the power electronics, through thermal management operations of the rotor and stator.

This is a strong point to note: through its software expertise, combined with its knowledge of electric motorization, FEV's offer allows the realization of highly complex tests associated with advanced automation, and also, through simulation, a reduction in bench tests.

Electric motor transmissions are subjected to a severe test: to test the gearbox, a high-speed e-transmission bench closes the device, reaching speeds of 18,000 rpm. The bench has been designed to meet various configurations, such as front and rear reducers, or to carry out cornering tests with differential. It should be noted that to produce this type of extremely technically advanced bench, FEV has carried out in-depth modal calculations so that it can handle high speeds and frequencies.  The bench is also equipped with a climatic chamber, allowing the gearbox to be tested down to -30°C.

The game is played in France, but also in Europe: FEV France participates in development and testing programs of European manufacturers, and in return benefits from all FEV's expertise in Germany. The variety of experiences enriches the French experts. This competence center represents a real opportunity for e-mobility.