Numerical Simulation of Electric Powertrain for Examining Real World Performance of EVs at Sub-Zero Temperatures 2021-01-1245

Electric Vehicles (EVs) are considered to be a worthy alternative to automobiles powered by internal combustion engines to achieve the goal of sustainable transportation. For their many known advantages, Li-ion cells are considered to be the most practical energy storage solution for the purpose of EVs propulsion currently. The capability of Li-ion cells to store energy in extreme cold operating temperatures is significantly lower than that at nominal operating temperatures due to greater power losses at cold temperatures. Therefore, it leads to degradation of performance of EVs in sub-zero temperatures.

The present work proposes a novel approach to use numerical simulation technique to build an EV model based on BMW i3 using GT Suite at sub-zero temperatures. The model is validated against experimental data obtained from Argonne National Laboratory for US06, HWY and UDDS legislative drive cycles. A real-world drive cycle representing real-world driving in Oxford, United Kingdom, was used for evaluating the effect of cold temperatures on the performance of the Electric vehicle. This paper presents the methodology followed for modelling an electric vehicle that represents BMW i3 EV, the scheme used for modelling the battery characteristics to include the effect of temperature and the resulting state of charge, internal resistance, efficiency, terminal current and power, energy consumption and loss characteristics at low ambient temperatures.