Simulation Workflow for Efficiency Calculation of a High-Performance Electric Powertrain
In battery electric vehicles the efficiency of the powertrain has a big impact on driving range and performance. As the overall efficiency of the electric powertrain is typically more than 90%, further optimization is challenging. Especially in high-performance electric vehicles, the efficiency over one or multiple laps on a racing track is crucial. It requires accurate estimation of power losses in each component of the powertrain and the analysis of the interaction between components under different operating conditions, such as temperature, speed/torque load point and battery state of charge (SOC). Thus, optimizing component efficiency is not equivalent to optimizing overall efficiency of the powertrain.
The following sections describe a system-level modeling approach for the powertrain that includes characterization of the inverter and electric machine and combines these models in a system-level drive cycle simulation to predict overall drive cycle efficiency.
This workflow was developed as part of the partnership between Ansys and the TAG Heuer Porsche Formula E Team to maximize powertrain efficiency of Porsche´s first fully electric race car — the Porsche 99X Electric.