A real power compensator based on flywheel energy storage system for E-bus flash charging

Due to the high percentage of air pollution created by heavy vehicles, the use of electric buses (E-buses) in cities has come to have higher priority. The E-bus flash charging strategy presented by ABB Company for TOSA Ebuses has demonstrated the feasibility of using E-buses; however, more thought must now be given to the energy supply for such flash charging stations to compensate for potential negative effects. The purpose of this paper is thus to provide a real power compensator for E-bus flash charging stations in order to develop and expand the use of the Ebusses in cities. A flywheel energy storage (FES)-based compensator for E-buses with ultra-fast chargers (flash charging) is thus presented to decrease the negative effects of such charging. The main negative impacts of flash charging are voltage instability, increased peak demand, power quality problems, increased power losses, and transformer overheating and over loading. FES-based flash charging stations thus offer several advantages such as environmentally friendliness, extended lifetimes, and high charging/discharging rates. The theoretical analysis and simulation results in this work support the feasibility of the proposed charging station for E-buses: based on the simulation results in MATLAB/SIMULINK, the proposed topology also decreases power quality problems and voltage drops.