Experimental assessment of energy saving due to trains regenerative braking in an electrified subway line

The paper deals with research activity conducted in order to determine the impact of regenerative braking techniques adopted on-board trains operating in electrified subway systems. Even though systems adopting this technique are very diffuse worldwide, experimental results demonstrating the impact on energy consumption are rarely made available for the scientific community. The paper reports the results of an extensive experimental activity conducted on an electrified subway line in Rome, in order to estimate the energy saving due to the techniques mentioned above. Since the monitoring activity of the system demand in the absence of regenerative braking had to be limited to the traffic peak hours of only two subsequent days, an available model being able to simulate the instantaneous demand profile of DC electrified subway power systems has been used in order to extend the numerical evaluations based on the experimental activity to a whole day of operation.