Modeling Climate Control Loads and the Impact on Vehicle Range for Last-Mile Electric Delivery Trucks in Cold Climates

In cold climates, cells in the high voltage battery of an electric vehicle are subject to environment-related performance degradation leading to a decrease in effective range. Active battery temperature regulation is often implemented in battery electric vehicles (BEVs) to mitigate the detrimental effects of extreme ambient temperatures on battery state of health and effective nominal capacity. However, low ambient temperature also impacts driver comfort leading to added auxiliary power demands to regulate the cabin temperature. This work focuses on evaluating the increased auxiliary power demand from vehicle heating, ventilation, and air condition (HVAC) systems in cold climates. Practical driving data was periodically collected from an instrumented medium-duty delivery vehicle over several cold winter months in Minnesota, USA. A simplified empirical model to estimate HVAC power requirements was developed from relevant temperature and air speed measurements within the vehicle. Using a physically-similar BEV model for simulations, the effects of driving in a range of cold ambient temperatures on the energy usage and effective vehicle range were assessed. The results show that reasonably accurate auxiliary power estimates (below 6% mean absolute percentage error) can be achieved through the proposed data-driven modeling approach. The developed methodology can aid future researchers in isolating the effects of ambient temperatures on battery performance degradation in cold ambient conditions.