RAILWAY AC POWER DISTRIBUTION SYSTEM USING THREE-PHASE BALANCING AND SINGLE-PHASE TRANSFORMERS Russian patent published in 2005 - IPC

FIELD: power distribution systems for railways.

SUBSTANCE: proposed system designed to supply railway equipment with ac power at 27.5 kV has pole-mounted traction substations spaced 200 - 240 km apart. These substations supply with power intermediate substations incorporating single-phase transformers and shorting-out switches through two-wire lines installed on contact-system poles. Two three-phase balancing transformers with grounded common point are installed in each pole-mounted traction substation; one of these transformers is operating and other one is stand-by transformer. Two-wire line is sectionalized trough one intermediate substation by means of two switches. Single-phase transformer is connected to each wire of two-wire line either side of sectionalizing switches through tee-junction of disconnecting switches which ensures parallel connection of all pole-mounted traction substations and intermediate substations to traction mains.

EFFECT: reduced number of pole-mounted traction substations and power loss in traction mains.

1 cl, 1 dwg