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In electric vehicles, supercapacitors (SC) are commonly used to perform a hybrid energy storage system (H-ESS). This approach, correctly coordinated and designed, can extend battery lifetime by limiting the battery current stress. SC are often coupled to DC/DC converters. To use the maximum energy stored in SC, high variability of the SC voltage is mandatory. Several time, the associated converter voltage ratio becomes too high and can produce instability of the system. Thus, at each time there is a minimal value for the SC voltage. This article proposes a dynamical limitation method for the SC voltage. The dynamic method is compared with a traditional constant limitation technique. Both are tested under the urban part of New European Driving Cycle with slope. The results point out that the dynamical limitation can ensure a better stability of the system regardless environment disturbance.

Nowadays energy storage is the keypoint of the development of electrical vehicles (EV) for charging time, autonomy and cost reasons. The main energy storage system for electrical vehicles is the battery and can cost up to one third of the vehicle price. Nevertheless the battery has limited power features and can be damaged by EV peak power requirements. Thus higher power density energy storage systems (such as supercapacitors) are used in combination with batteries (multisource EV). A reduced-scale EV demonstrator has been developed to present the concept of multi-source EV to high school and undergraduate students. The aim of this demonstrator is to highlight the interest of research on electric vehicle to attract students in this research topic.