1D-3D Online Coupled Transient Analysis for Powertrain-Control Integrated Thermal Management in an Electric Vehicle 2021-01-0237

Thermal management in electric vehicles (EVs) has attracted more attention due to its increasing significance, and computer aided engineering (CAE) plays an important role in its development. A 1D-3D online coupling approach is proposed to completely characterize transient thermal performance of an electric vehicle on a high performance computer (HPC) platform. The 1D thermal management model, consisting of air conditioning, motor cooling and battery cooling systems, is integrated with the 1D control strategy model and powertrain model consisting of motor, battery, driver and vehicle models. The 3D model is established for the air flow around the full vehicle and through its underhood. The 3D model gives boundaries such as heat exchanger air flowrates and heat flows on some component surfaces to the 1D model, while 1D gives back boundaries such as heat exchanger heat loads, component surface temperatures and fan speed simultaneously. In this way, a complete closed-loop coupling is realized and no input boundary condition is required in the 1D-3D model for a certain road map. Realization of the 1D-3D online coupling method on an HPC platform is introduced, since it’s necessary for the simulations to be completed in a reasonable time period. For typical driving cycles including WLTC(35°C), NEDC(35°C) and 120kph(35°C), transient simulations are performed and the results are discussed. The simulation results reasonably reflect variations of the physical parameters, which proves the 1D-3D online coupling method to be useful tool, especially at early stages of development. At the next stage, full vehicle experiments will be performed to calibrate parameters including coolant temperatures and flowrates, component temperatures, refrigerant temperatures and pressures, as well as component electric consumptions of the 1D-3D model, which will be discussed in another paper due to space limitation.