Optimizing heavy duty vehicle battery size and its impact on charging strategy

Abstract

The electrification of heavy-duty trucks plays an important role in carbonizing the transport sector, although there are many crucial variables that needs further research before reaching a market penetration. This thesis focuses on the battery size, driving profile and charging behaviors of heavy-duty battery electric vehicles (HD-BEV). Characteristic driving profiles for six different vocations were created from aggregated driving data. A cost-minimizing optimization model was created to determine the battery sizes of the different vocations for a characteristic week. The model also cost-optimizes the charging pattern of the different vocations divided among charging powers ranging from 22 kW to 1000 kW. The results show that the battery sizes range from 188 kWh to 632 kWh for the various vocations. Furthermore, it is found that most of the electricity charged comes from the 22 kW charger for all but one long-distance vocation where most of the electricity is charged using a 350 kW fast charger. Although the 350 kW to 1000 kW chargers are never used in the base cases. The results also suggest that for half of the vocations, charging is equally distributed between night and daytime and that the other half charges the majority of their energy during night time. Sensitivity analyses suggests that the cost of battery has a relatively small effect on battery size and charging strategy. In contrast, vehicle consumption had a significant impact on battery size and charging strategy where the use of 500 kW and 1MW chargers is observed.