Sequential supply for electrical transportation vehicles: properties of the fast energy transfer between supercapacitive tanks

A new feeding concept for electrical transportation systems is presented, based on supercapacitive energy storage. Supercapacitors are new and powerful components for energy storage. Compared with batteries, the amount of energy they can store is low and does not allow a large vehicle autonomy. Because supercapacitors have the property to be re-loadable in a few seconds, a sequential supply system has been developed, considering repetitive feeding at the stops. To solve the problem of the needed high power amount to reach short refill times, a solution is proposed which consists of using an intermediary supercapacitive tank placed at fixed stations, which is refilled between the bus arrivals with a much lower power. In addition to the description of the needed power electronic converters, theoretical and experimental results are presented, defining the controlled profile of the instantaneous power-level, in order to achieve a fast energy transfer between two supercapacitive tanks.