A study of urban electric bus with a fast charging energy storage system based on lithium battery and supercapacitors

Nowadays considerable resources have been invested on low emission passenger vehicle both for private and public transportation. A feasible solution for urban buses is a full electrical traction system fed by supercapacitor that can be recharged at each bus stop while people are getting on and off. In facts such vehicles covers very short distance between consecutive stops, usually less than half a kilometer; for these reasons the energy storage system needs to provide high peak of power and low amount of energy. Then the most appropriate storage device is constituted by supercapacitor that are capable of fast charging during bus stops. At last in order to consider the worst operating condition for the bus (like traffic jam of higher distance to be covered) also a conventional battery it is installed.