2nd ICAI 2022

International Conference on Automotive Industry 2022

Mladá Boleslav, Czech Republic

BEV are much less energy-demanding to operate, they have a more limited operational range than ICE cars. Due to the high efficiency of the electrical propulsion, it also cannot be relied upon to heat the passenger space up, using the heat from its losses. This leads to further energy consumption demands and therefore reduced range. According to the available data (Vražić, 2014), (De Gennaro, 2015), (Fiori, 2016), (GEOTAB [online], 2020) it is, in some cases of BEV, necessary to expect up to 50% of the energy stored in the traction battery to be used to power auxiliary devices – primarily to air-condition the vehicle. This study presents the measurement results of power consumption and efficiency values of BEV from real operation, during the summer of 2021 and winter of 2021/2022, and provides a summary of what kind of energy consumption and its distribution among the critical parts of the vehicle can be expected from modern BEV. The measurement from the summer season was repeated in the winter using the same methods to determine the practical influence of ambient temperature. The paper also includes how various types of vehicle charging affect the end-usage of BEV. The goal of the text is not to bring new theoretical findings regarding the BEV operation, but rather thoroughly present the experience with using BEV in the Czech conditions. The acquired data may be used as a reference for validation of models in terms of estimated BEV range (Wang, JQ, 2018), (Wang, JB, 2017), (Fiori, 2016). 2. Real Power Consumption of a BEV in the Czech conditions One of the biggest problems, related purely to electrical vehicles, is their operation range. In order to determine the values achievable by the selected BEV, it is first necessary to find out how much energy is actually consumed when driving. The overall BEV consumption can be subdivided in to 4 basic segments: • Traction, i.e. the energy required by the vehicle’s propulsion system • Air conditioning (HVAC), i.e. the energy required to heat or cool the passenger space • 12 V system, i.e. the energy consumed by control units and related on-board technology of the vehicle • Traction battery management, i.e. the energy required for the heating or cooling of the traction battery It is obvious that the consumption values described above will not be constant and their magnitude and overall distribution of the consumption will depend on the operational mode of the electric car. This mode is determined primarily by the profile of the driven route, driving speed, ambient temperature and usage of recuperation. To determine the needs of BEV, the test routes that are typical for Czech conditions were selected. Several test trips were driven for each route type, confirming the repeatability of the measurements. All of the trips had their start and end at the same spot. A/C was on during summer trips, while heating was on during winter trips. Electrical heating of seats and the steering wheel was not used. The values below are derived from the combination of speed, position, altitude above sea level (measured using external GPS module), also values copied from the car’s

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