PROTECTIVE CIRCUIT FOR ADJACENT FEEDERS OF DC TRACTION SYSTEM (ALTERNATIVES)

摘要

FIELD: protective gear for dc traction substation feeders. SUBSTANCE: protective circuit has nonpolarized circuit breakers and primary protective sensors. Magnetic core of each of mentioned sensors mounts additional coil connected to first voltage relay through diode. Positive voltage of dc control current is applied to one lead of normally open contact of relay. Its other lead is connected to starting lead of second voltage relay coil and negative voltage of control current is applied to its finishing lead. Connected through normally open contacts of this relay is additional coil of right-hand feeder differential shunt relay. Diodes incorporated in additional-coil circuits of left- and right-hand feeders are connected so that diode of left-hand feeder starts passing current under influence of emf induced in additional-coil circuit during negative current step in left-hand feeder. Right-hand feeder diode starts passing current during positive current step of right-hand feeder with voltage relay contacts in right-hand feeder being closed. EFFECT: eliminating unwanted operation of circuit breakers in adjacent feeders. 2 cl, 3 dwg