Battery Pack Electrothermal Coupled Model or System Analysis
A battery pack model is required for many applications, including electric powertrain simulation, BMS design and digital twin generation. This webinar presents an electrothermal coupled Li-ion battery pack model with cold plate liquid cooling, a common design in electric vehicles. The model starts from the hybrid pulse power characterization (HPPC) test data at different state of charge (SoC) and temperature levels. Such information is used for cell-level battery equivalent circuit model (ECM) parameter identification. Multiple cell ECMs are connected in series/parallel to create a module ECM. The battery thermal performance of the module is simulated first by computational fluid dynamics (CFD) for the module. Then, a thermal reduced-order model (ROM) is created out of the CFD solution. The thermal ROM is two-way coupled with the battery module ECM to form a complete battery module model. Different modules will have different heat transfer coefficient values, calculated separately from a cold plate conjugate heat transfer analysis. Multiple module models are connected to create a battery pack model. The complete pack model can be used for system simulation or BMS design using Ansys system tools or any third-party system tool through functional mock-up units (FMUs).