An Adaptive Fuzzy Logic-Based Energy Management Strategy on Battery/Ultracapacitor Hybrid Electric Vehicles

One of the key issues for the development of electric vehicles (EVs) is the requirement of a supervisory energy management strategy, especially for those with hybrid energy storage systems. An adaptive fuzzy logic-based energy management strategy (AFEMS) is proposed in this paper to determine the power split between the battery pack and the ultracapacitor (UC) pack. A fuzzy logic controller is used due to the complex real-time control issue. Furthermore, it does not need the knowledge of the driving cycle ahead of time. The underlying principles of this adaptive fuzzy logic controller are to maximize the system efficiency, to minimize the battery current variation, and to minimize UC state of charge (SOC) difference. NetLogo is used to assess the performance of the proposed method. Compared with other three energy management strategies, the simulation and experimental results show that the proposed AFEMS promises a better comprehensive control performance in terms of the system efficiency, the battery current variation, and differences in the UC SOC, for both congested city driving and highway driving situations.