Characterizing BEV Powertrain Energy Consumption, Efficiency, and Range During Official and Drive Cycles From Gothenburg, Sweden

Journal article, 2016

In this paper, the energy consumption per distance of a battery electric vehicle (BEV) is comprehensively investigated for various official and gathered real-world drive cycles, including the powertrain's cycle average efficiency. The powertrain component losses are modeled with a high level of detail, and they are functions of both speed and load. It is shown that the difference in calculated drive-cycle energy consumption may be up to 16% when using two different acceleration approximation methods and one speed sample per second, which is an interval commonly used among drive cycles. In contrast to combustion engine vehicles (CEVs), BEV energy consumption per distance generally increases with increasing cycle speed levels, and time spent at high speed levels have the largest influence on the consumption. The effect of acceleration on energy consumption is seen to be considerably reduced due to regenerative braking as it reduces the consumption by up to 49% on an acceleration intense cycle. Even when the regenerative area is limited to about half, the decrease in driving range is less than 1% for most cycles. By introducing the concept of overconsumption, it is shown that much time spent at high levels of acceleration is one of the largest contributors to excess energy consumption for BEVs. Furthermore, the found cycle average powertrain efficiencies are quite similar between the different cycles, with 82%–90% during propulsion and only slightly lower during braking, i.e., much less speed dependent than for CEVs.