Emergency supply to safety systems of long railway tunnels

The paper reports an analysis of emergency power supply, by a generator set, for safety systems installed in long railway tunnels. The generator set guarantees the service continuity, during a blackout event, to supply signaling systems, telecommunications, emergency lighting and auxiliary equipment for electrical substations, including the relative cooling systems. The main issues analyzed were the flowing of reactive power due to the cables length used and the transient energization during the start-up phase. The capability curve of the generator has been also verified and a shunt reactor has been designed for reactive power compensation. The tunnel studied concerns the Naples-Bari railway line.