FIELD: electrical equipment.
SUBSTANCE: traction substations protections backing up device contains three parallel branches for the supply line phase currents difference monitoring, each of which consists of in-series connected adders in the form of two back-to-back connected measuring current transformers, current increment sensor, threshold element in the form of current relay, inverter and the AND gate, as well as the supply line single-phase short-circuits control unit, which is the in-series connected zero sequence current sensor in the form of residual current measuring transformer, threshold element in the form of current relay, inverter and the AND gate, as well as the OR gate, time relay and the output element. At that, forming the traction substations protections backing up device six inputs each branch adder first and second inputs, are connected to the supply line phase wires, the output element output is connected to the supply line switch drive, supply line phase currents difference monitoring threshold element each branch output is connected to the other branches AND gate corresponding inputs, each branch AND gate output is connected to the OR gate corresponding input, the time relay output is connected to the output element input. Said monitoring unit zero sequence current sensor input forms the traction substations protections backing up device seventh input and is connected to the step-down substation transformer zero point output, said monitoring unit AND gate second input is connected to the OR gate output, and the said monitoring unit AND gate output is to the time relay input.
EFFECT: technical result consists in increase in the device functional stability to the single-phase short-circuit in the supply line to the traction substation transformer at the traction substations protections backing up device lower regulatory time delay in comparison with the supply line main protection device standard time delay.
1 cl, 1 dwg
