SU97104A1 - Relay device for longitudinal differential protection of lines - Google Patents

Description

A relay device for longitudinal-differential protection of lines with control wires, equipped with an induction relay, having a four-pole magnetic system with an excitation winding consisting of four coils located on the magnetic core, and with a braking and working windings located on two opposite poles magnetic system.

In the described device, as compared with the known ones, the conditions of protection detuning during through short circuits are improved, when the capacity of the connecting wires affects.

This is achieved through the use of active resistance, laziness, shunting the excitation winding of the relay, and an auxiliary transformer. The resistance, connected in parallel to the field winding connected in series with the brake winding, ensures the creation of a braking torque in the relay, and the auxiliary transformer, the primary winding of which is connected in series

with the brake winding and the excitation winding into the current transformer circuit, serves to obtain e. d. in the circuit of the control wires to which the working winding is connected.

In a modified version of the device, the active resistance, the circuit is connected in parallel to the torus of the useful winding (and not the excitation winding): In this case, an electrical capacitor is included in the circuit of the working winding and secondary winding of the auxiliary transformer, which serves to increase the sensitivity of protection with a purely active resistance of the control wires and for y: her sensitivities in the presence of capacitance between the control conductors.

FIG. 1 and 2 shows the electrical circuit of two variants of the device.

An excitation winding consisting of four coils 2 is placed on the magnetic core /. At one pole 3 there is a working winding 4, and at the opposite pole .5 there is a torus winding about. In parallel to the field winding, an active

resistance /. To obtain e. d. in the circuit of the control wires 8, to which the working winding 4 is connected, serves an auxiliary transformer 9, the magnetic circuit of which has an air gap. The primary winding 10 of this transformer is connected in series with the brake winding 6 and the field winding.

In the normal mode, on the protected area or during a through short circuit, the currents flowing through the windings of the relays installed at the ends of the protection. the plot is equal and directed in one direction. At the same time they are equal, but opposite to the direction of e. d. secondary windings of auxiliary transformers 9. The current in the control wire circuit is zero and there is a braking torque on both relays.

If the protected area is damaged, the current in the circuit of the control wires will no longer be equal to zero, since in the case of double-sided threading of the damage site, doubled e acts on the value of the control wires. d. secondary winding of auxiliary transformer, and in the case of one-sided filament-emf the secondary winding of the transformer of the relay, the winding of which flows around the emergency current. In this case, both relays (and, whether one of them, depending on whether the damage site is powered from two or from one side), except the braking one, also have a working moment. When the working moment exceeds the sum of the braking and mechanical moments, the relay is activated and the damaged section of the line is turned off.

FIG. 2 shows the second variant of the described relay device. Here active resistance 7 is connected in parallel to the brake winding 6 (and not

field winding). A capacitor // is connected to the secondary winding circuit of the auxiliary transformer 9 and the working winding, the purpose of which is to increase the sensitivity of the relay at the purely active nature of the resistance of the control wires and decrease the sensitivity in the presence of capacitance between the coitral wires.

Subject invention

1. Relay device for longitudinal-differential protection of lines with control wires, equipped with an induction relay, having a four-pole magnetic system with an excitation winding consisting of four coils, spaced along the magnetic-conductor frame, and with a braking and working windings located at two opposite poles mentioned of an intrinsic nagging system, which differs from H1, in that, in order to create a braking moment in the relay, a paratube excitation winding connected in series with the braking winding is included ivnoe resistance and for preparation of e. d. An auxiliary transformer is used in the circuit of the control wires to which the working winding is connected, the nervous winding of which is connected in series with the brake winding and the excitation winding at the price of the current transformer.

2. Change of the relay device non. 1, that the active resistance is connected in parallel with the brake winding (and not the excitation winding) and an electrical capacitor is connected to the working winding and the secondary winding of the auxiliary transformer.

The priority of paragraphs 2-20 of February 1952.