PROTECTIVE CIRCUIT OF DC TRACTION NETWORK FEEDERS (ALTERNATIVES) Russian patent published in 2005 - IPC

FIELD: protective devices for adjacent feeders of direct-current traction substations.

SUBSTANCE: protective circuit for dc traction network adjacent feeders separated by insulating air gap has nonpolarized switches and primary protective transducers provided with additional coils; control coils of feeder switches are supplied with power through normally closed contacts of primary protective transducers; additional coils of feeder primary protective transducers are connected in series so that starting lead of primary protective transducer additional coil of feeder which electric locomotive leaves is connected to finishing lead of primary protective transducer additional coil of feeder whereon electric locomotive moves; connected to two remaining leads of series-connected additional coils of primary protective transducers is coil of voltage relay whose normally closed contacts are connected in parallel with contacts of switch primary protective transducer of feeder whereon electric locomotive moves. Alternative design of protective circuit is distinguished in that connected to two remaining leads of series-connected coils of primary protective transducers are series-connected coils of two identical voltage relays whose normally closed contacts of first of them are connected in parallel with primary protective transducer contacts of switch of feeder that electric locomotive leaves.

EFFECT: simplified circuit arrangement, enhanced reliability of protective gear.

2 cl, 2 dwg