DIFFERENTIAL PROTECTION SYSTEM FOR DIRECT-CURRENT TRACTION NETWORK Russian patent published in 2015 - IPC H02H3/00 

FIELD: electricity.

SUBSTANCE: differential protection system for direct-current traction network provides continuous monitoring feeder load current and at the same currents consumed by each vehicle at the protected section of the traction network. To this end the system includes two types of devices: on-board module installed at each vehicle and feeder module installed in line circuit-breaker cell. The on-board module is represented by a package of devices containing measurement units and consumption current data processing units, GPS/GLONASS receiver, interface converter, modem and driver signalling unit. The feeder module comprises units for processing data on feeder load current and currents consumed by vehicles located at a protected section of the traction network, feeder modem, interface converter, driver's signal generating unit and unit shaping commands for switching off line circuit-breaker and switching on alarm signalling. Data on currents consumed by vehicles is transmitted by on-board modems through wireless communication channel to feeder module, which sumps up signals from vehicles and analyses state of the traction network regarding non-availability of short-circuiting based on comparison of feeder load current and total current consumed by rolling stock at a protected section of the traction network. In result, when short circuiting is available signal for switching off line circuit-breaker is generated, and in case of overload mode signal is generated to drivers to switch over to stopping mode from traction mode.

EFFECT: improved reliability in actuation of protection from short circuit currents, reduced probability of false operation.

2 dwg