Abstract: In this paper an alternative energy storage system in the drive train of a hybrid electric vehicle is investigated. In particular, it concentrates on the potential reduction of the stresses of the battery when electrochemical capacitors, a.k.a super capacitors, are added as high power energy storage. Different control strategies are evaluated and an estimation of the performance is given. In order to verify the simulation results, a downscaled HEV drive train consisting of NiMH batteries, electrochemical capacitors, a DC/DC converter and an external load, is built and tested. The results show a significantly reduction in battery stresses and a good agreement between the models used in simulations and the laboratory system. Finally, a weight optimization of such a system is briefly discussed.
Keywords: Capacitive energy storage, Electrochemical devices, Energy management, Energy storage, Power electronics, Road vehicle electric propulsion, Road vehicle power systems.