Optimization of storage devices for regenerative braking energy in subway systems

The paper deals with the actual theme of power management in traction systems presenting a study about the use of regenerative braking energy in electric subway transportation. Storage systems on board of the vehicles or on fixed plants can give advantages both to contain the costs of the electric power and to limit power losses along the traction line. Moreover, other technical advantages can be obtained as, for example, the reduction of contact line voltage fluctuations. With reference to a real case, one of the Milan subway lines, a software program is implemented in order to simulate the electric power flow and to optimize the storage device size and control