At Shinkansen substations, a pair of single-phase power sources are provided with different phases. In order to change one source to the other in steps with cars running, therefore, a changeover section (about 1 km long) with changeover switches is installed.
  We have developed a new type protective relay to find failed changeover switches by using an optical current transformer for Shinkansen changeover switches.

Copyright (c) 2001 Railway Technical Research Institute