Conception and implementation of a charging station for electric buses in public transport

The idea for fully electric bus operation following the DockingPrinciple was conceived at the Fraunhofer IVI over ten years ago. The term DockingPrinciple stands for a new way of supplying energy for electric vehicles used in public transport, with an on-board energy storage unit as the vehicle’s sole source of energy. This storage unit takes in energy from fast charging stations (docking stations) installed along the way and releases it according to the demands of the vehicle propulsion system and the electric auxiliaries. From the current point of view, there are two feasible concepts for recharging the vehicle’s storage unit. Firstly, the energy needed for the upcoming tour can be provided during a fast charging process of several minutes’ length with a power of typically 250 kW. Secondly, considering the currently available storage technologies, it is sensible to install additional charging stations at bus stops. Doing so allows for longer routes while avoiding disproportionately high costs for the on-board energy storage units. At selected stops, a time slot of 15 seconds is available during which the energy storage can be recharged with a power of 700 kW. This process is called pulse charging.