Research on the energy management strategy of extended range electric vehicles based on a hybrid energy storage system

Extended range electric vehicles (EREVs) are an effective solution to solve the lack of driving range of pure electric vehicles. Reducing the fuel consumption of EREVs and prolonging the service lifetime of battery play a positive role in solving environmental pollution and energy crisis. In this paper, hybrid energy storage system (HESS) is introduced into EREVs, and two energy management strategies based on HESS are proposed to reduce fuel consumption and prolonging the service life of battery. This paper proposes two energy management strategies for EREVs based on a HESS to reduce fuel consumption and the amount of energy flowing through the battery. HESS adopts the rule based energy management strategy, whereas Auxiliary power unit (APU) adopts the equivalent fuel consumption minimization strategy (ECMS) or the rule-based energy management strategy as its first and second hierarchical energy management strategies respectively, both of which are embedded into the charge depleting/charge sustaining (CD/CS) control strategy. A simulation model for an EREV is built in AVL Cruise to verify the effectiveness of these strategies. The battery charge and discharge C-rate and the energy consumption of EREVs without HESS under the ECMS and rule-based energy management strategy are then compared. Results show that under the first hierarchical energy management strategy, the average discharge C-rate and cumulative ampere hours of the battery are the lowest, thereby reducing its operating load and extending its service lifetime. Meanwhile, for those EREVs without HESS, using the rule-based energy management strategy can reduce fuel consumption by 11.33%, whereas using ECMS increases fuel consumption by no more than 1.61%. Therefore, the first hierarchical energy management strategy proposed in this study can effectively extend the service lifetime of the battery and reduce the fuel economy of EREVs. (c) 2022 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).