Researchers in Germany have developed a battery-in-the-loop testing environment for electric vehicle batteries that combines physical components with mathematical simulations of vehicles.
The team at the Fraunhofer Institute for Structural Durability and System Reliability LBF in Darmstadt say this is the first to enable lab trials under real-world conditions.
The current and voltage characteristics of the a battery pack used in electric vehicles is just one factor that needs to be tested. Other key elements to test include the wear and tear of electrical, mechanical and thermal stress when negotiating hairpin bends, bouncing over gravel roads strewn with potholes and motoring in the sweltering summer heat. This is why new battery systems have to be comprehensively tested in real world environments before installation in vehicles.
However, conventional lab tests are a far cry from reality, and real-world trials have to wait until engineers deliver a drivable prototype of the vehicle. If undetected problems surface at that late a stage, then the necessary modifications can cost a lot of time and money.
The Battery-in-the-Loop @ LBF (MEF-BILL) project breaks down the loads placed on batteries can be broken down into three domains – the electrical loads primarily attributable to current flows, the vehicular motion, and the climatic aspects. The conventional approach has been to test these three factors separately in lab with trials that have standard runtimes. I
n the real world, however, these factors are interdependent and affect each other in complex ways so the project allows these loads and their interaction to be evaluated simultaneously in the Fraunhofer LBF testing environment, alongside a real-time-enabled, computerized model of the vehicle.
This battery-in-the-loop approach allows the researchers to simulate the vehicle and its performance on very different types of roads. This simulation enables them to determine the loads that would also affect the battery in the actual conditions prevailing out there in the real world.
“We are now bringing the road into the laboratory