Shinkansen Technology Tips

Electric power network in Japan are 50Hz in Eastern Jap an from Kanto to the North and 60Hz in Western Japan from Chubu to the West, and are divided in the vicinity of Tokaido, with the Fuji river serving as the boundary.   To provide a through operation by means of AC electric cars between the two regions with different frequencies, frequencies must be standardized by ground equipment or dual-purpose 50/60 Hz rolling stock must be used . For the Tokaido Shinkansen , power has been supplied at a uniform frequency of 60Hz by means of ground facilities because of reliability improvements through simplification of the electrical equipment of rolling stock and to achieve lighter rolling stock . However, for the Hokuriku Shinkansen which  has started commercial operation in 1997, a 50/60 Hz dual-purpose rolling stock system was adopted . Reasons are as follows: (1) technological advancements enabled to produce lighter 50/60 Hz dual-purpose rolling stock . (2) a freque

AC feeding voltage of a conventional line (which means "urban train without high-speed") is a single-phase AC voltage of 20 kV, but a standard voltage of the Shinkansen Overhead Contact Line is 50Hz AC voltage of 25 kV . The main reasons for adopting an AC voltage of 25 kV as the standard voltage are as follows: (1) With 1,500 V DC electrification, the collected current is large, the overhead contact line is thick, and the traction substation interval is 3 to 5 km, which means high construction costs . (2) With 1,500 V DC electrification, the power collectors are heavy and tracking during high-speed operation is difficult. (3) With 1,500 V DC electrification, selective shutting off a fault current is difficult because the fault current value and load current value are comparable. (4) Because the Shinkansen is a new line, and tunnels and other facilities are newly provided, sufficient insulation clearance can be secured from the outset, and there are barely any pr