Evaluation of driving resistance and energy consumption in electric vehicles under various ambient and tire temperatures using real-world driving data

초록

In cold environments, energy consumption in electric vehicles increases significantly due to multiple factors, with driving resistance being one of the important contributors. Among its components, aerodynamic drag and rolling resistance, collectively referred to as road load, are especially sensitive to temperature. However, chassis dynamometer tests used for efficiency certification typically apply only a 10 % increase in road load under cold temperatures, which may underestimate energy consumption in real-world driving. This study analyzes the effects of ambient temperature, vehicle mass, tire pressure, and tire temperature on road load and energy consumption using real-world driving tests. When ambient temperature dropped from 25 degrees C to 0 degrees C, energy consumption increased by 20.8 %, mainly due to a substantial rise in rolling resistance. While ambient temperature influences rolling resistance indirectly, tire temperature was found to be a more direct determinant. Even under identical ambient conditions, rolling resistance before tire warm-up was 13.6 % higher than after warm-up. These differences were reflected in energy consumption estimates based on standard driving cycles. For example, under the UDDS cycle at -7 degrees C, the tire temperature-based model estimated 12.0 % more energy consumption than the ambient temperature-based model. Considering the physical mechanisms behind tire rolling resistance, incorporating tire temperature into the resistance model enables a more realistic representation of energy loss under cold-start conditions. This approach can enhance the reliability of energy consumption simulations and improve the effectiveness of driving range predictions.

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