Dimensioning of ultra capacitors used for range extension in electric vehicles

Electric vehicles (EV) require energy storage with high power and high energy-density. A hybrid-storage-system combining battery (high energy density) and ultra-capacitor (high power density) to supply a motor is logical. This paper will present an efficient way of dimensioning the ultra-capacitor of this system. The optimal size is determined by applying real driving cycles to a dynamics simulation. The dynamics model used for the simulation is explained and the results for different driving cycles are presented. In addition a lifetime estimation for the ultra-capacitor (UC) using available datasheets is performed with the same simulation.