Testing Battery Sensitivities of Electric Aircraft Systems Using a Battery Pack Surrogate

Many eVTOL and electric aircraft systems are highly sensitive to battery performance, states, algorithms and behavior, which necessitates thorough testing. However, lab testing with real battery packs is not practical or desirable in most cases due to potential issues with safety, availability, cost, energy, and test coverage. A battery pack surrogate hard-ware-in-the-loop (HIL) test system may be used in place of the battery in order to safely and efficiently test many battery-sensitive aircraft systems across an extended range of battery conditions. This paper describes an 800V battery pack surrogate comprised of commercially available components including battery cell simulators providing over 200 cells of simulation, as well as signal and power IO, communications, cell models, a real-time controller, and battery management system (BMS). Important design considerations including safety, isolation, topologies, and interconnections are addressed, and applications for systems integration lab (SIL) and iron bird testing are presented.