Volume 47

How electric vehicle energy flow is distributed in low-temperature conditions under real-world driving? Jingyang Hua, Binbin Yu, Zhenyu Hou, Dandong Wang, Junye Shi and Jiangping Chen

Abstract

Electric vehicles are essential for decarbonizing transport, though many challenges lie ahead. One issue that has received recent attention is the gap between real-world battery energy consumption and results from laboratory tests, especially in winter, where the operational status of thermal management system (TMS), including air conditioning (AC) system, varies greatly. Despite the critical importance of TMS for safety anddriving range performance, the precise contribution of TMS to battery and cabin energy consumption remains elusive. Through a comprehensive expermental analysis of the energy flow characteristics and consumption patterns of a certain four-wheel-drive multi-purpose vehicle (MPV) under diverse low-temperature conditions (-7 °C, -20 °C), we elucidated the operational traits of the primary energy-consuming components in cold environments, with particular emphasis on the vehicle’s overall energy consumption. Based on the standardized CLTC-P test procedure, our experimental findings reveal a pronounced increase in the overall energy consumption of EVs in low-temperature environments, with energy consumption recorded as 6.8 kW.h, and 8.9 kW.h, respectively. Notably, the energy consumption attributed to the battery thermal management system accounts for 54.0 %, and 59.8 %, while the propulsion system’s motor drive energy consumption represents 43.8 %, and 38.0 %, respectively. Furthermore, under the two low-temperature conditions, the activation of the air conditioning system incurs an additional energy consumption of 16.60 %, and 18.44 %, respectively. Notably, the energy consumption surge is more pronounced when the air conditioning is activated, with energy consumption increasing by up to 287.65 % at -20 °C, compared with the standard working condition, corresponding to a 74.20 % decline in driving range, which further elucidating the mechanistic effects of temperature variations on the performance of the thermal management system in electric vehicles. These research findings not only contribute to a deeper understanding of the energy utilization status of electric vehicles in adverse climate conditions but also provide crucial guidance for the design of more environmentally sustainable and efficient electric vehicles, thereby promoting the development of sustainable transportation systems.

Keywords Electric vehicles, low temperature environment, energy flow, thermal system, vehicle test