Managing the Italian High-Speed Railway Network: Provisions for Reducing Interference Between Electric Traction Systems

The Italian high-speed (HS) railway network consists of about 1,000 km of double track lines. It is still growing, and a new section of about 50 km will be put in service in 2016. The HS railway network is broadly equipped, especially in the countryside, with a 2 x 25 kV, 50 Hz electrification system, while in the urban areas as well as for the HS Rome-Florence line, a 3 kV direct current (dc) electrification system was adopted. The peculiarity of the Italian HS system is the high number of interconnections with the former railway network, called the conventional railway. Twenty double-track interconnections are currently in operation to manage many traffic routes. Since December 2005, when the first 2 x 25 kV alternating current (ac) line was placed into service, the Italian railway infrastructure management has gained experience in managing the electrical interferences between the 3 kV dc and the 2 x 25 kV ac electrification systems. This article refers to the main technical aspect related to more than ten years of experience in handling the boundary between different electric traction systems. Figure 1 gives an overview of the Italian HS network. For each line, the first year of service, the relevant electrification system, and the number of interconnections with the conventional railway network are given.