SU756323A1 - Device for determining direction of short circuiting in overhead power transmission line with branches - Google Patents

Description

one

The invention relates to devices for determining the direction of a short circuit search in branched air electric networks of 6-10, 35 kV.

Known indicator of the damaged area (UPU) [ΐ] and short circuit indicator (UKZ) [2].

The UPU and UKZ contain an induction current transducer, a rectifier and a trigger indicator. In the UPU as a trigger indicator is used polarized relay, in. the state of the contacts of which is defined * - ’. the direction of the search for short circuit (ke) is given. In UKZ, the trigger indicator is a magnetic memory block, and its state is determined by the deviation of the magnetic arrow. The UPU and UKZ also contain antenna voltage converters, with the help of which they carry out. Their return to the starting position is 25

The closest in technical essence to the invention is the automatic pointer of the damaged direction (AUPN) [3]. AUPN contains two current sensors (DT), uetanov2

(Lenny on the phase wire and connected via rectifiers to the inputs of the trigger indicator.

The AUPN is made in the form of a block, in the lower part of which a cylindrical flag is placed under a glass bell, signaling at a certain angle that there is a short circuit in the controlled direction in red, and in the upper part there is an opening through which the phase conductor of the controlled line passes. Both DT AUPNs monitor the same current, and the rectified signals from them are mutually subtracted in the display unit. DT used in the return circuit is quickly sated, so the signal from it prevails at low (operating) currents, while at high currents corresponding to the short-circuit mode, the signal from the unsaturated DT triggering signal prevails.

AUPN has the following significant drawbacks:

- counter-inclusion of diesel fuel leads to the need to regulate the operating currents of the line above and below, because when too small and too low

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com large currents are not provided required to return the difference sig- ^! The time between the return and actuation DT. AUPN current return is possible only at load currents of more than 5 A, which is not provided for most lines, especially at night, ³

- the complexity of the magnetic system AUPN does not allow you to make it detachable, so it requires cutting the wires during installation and replacement.

The principal disadvantage of all these devices with automatic return (AUPN, UKZ, UPU) is the loss of information about the direction of the last k. S. after the line is turned on. Such pointers are not received.

searchable unstable k.

Although unstable. H. they do not cause the line to shut down, but the search for the location of the bridges that are necessary for monitoring the network status presents 20 serious difficulties. In this connection, a pointer is of interest, which would preserve information about the direction of the last k. Z., Regardless of whether it was stable or unstable 25.

The purpose of the invention is to expand the functionality by fixing unstable to.

To achieve this goal in the device for determining the direction of the ^short- circuit ^k . on overhead lines with two current sensors, one of which is installed on the branch, the outputs of these current sensors are connected through a straight-out to the corresponding inputs of the response indicator, the second current sensor is installed behind the branch point on the air line.

In addition, the second current sensor 40

made in the form of unsaturated current transformer.

The current sensors are made in the form of induction current transducers, with the induction current transducer in the line being installed parallel to the branch wires, and the induction current transducer in the branch line being installed parallel to the main wires. 50

In order to improve noise immunity, two differentiating units were introduced, connected between the outputs of the respective rectifiers and the inputs of the operation indicator.

The trigger indicator is designed as a block of magnetic memory with an arrow.

FIG. 1 is a schematic diagram of the proposed device, 'in FIG. 2 is a diagram of a device in which current sensors are made in the form of induction current transducers; FIG. -3 - placement of induction current transducers on the branch support of the power line;

in fig. 4 is a schematic of a device with differentiating units; FIG. 5 embodiment of the trigger indicator.

As shown in FIG. 1, first DT

1 is installed on the phase conductor 2 of the line behind the branch point and connected via a rectifier 3 to the indicator 4. The second input of the indicator 4 is connected via the second rectifier 5 to the second DT 6 installed on the branch 7 of the same phase conductor.

FIG. 2 shows a device using induction current transducers (IPT) 8 and 9. IPT 8 is installed between two wires

2 main part of the line behind the branching point at an insulating distance from the wires and controls the current of this part of the line. IPT 9 is installed between the two wires of the branch 7 and controls the branch current. IPT 8 through the rectifier 3 is connected

with one of the inputs of the operation indicator 4, and the IPT 9 through the second rectifier 5 is connected with the second input of the operation indicator.

As shown in FIG. 3, IPT 8 is located parallel to the wires of branch 7, and IPT 9 is parallel to wires 2 of the trunk line. In addition, the IPT 8 is removed using the bracket 10 at a distance of 0.5–0.8 m to eliminate the influence of unbranched currents on the highway and jumpers to the branch on it, and the IPT 9 is fixed with a bracket 11 at a distance of 0.5 m from the support that he was between the wires of the branch at an equal distance. Both brackets 10 and 11 are attached to a cross-bar 12 "fixed on line support 13. Thanks to this arrangement, IPT 8 controls only the main current behind the branch point, and IPT 9 only the branch current.

In order to improve the noise immunity of the device between the rectifiers 5 and 5 and the trigger indicator 4, differentiating units 14 and 15 are also included (see FIG. 4), eliminating the influence of operating currents on the operation of the device.

The trigger indicator 4 (see Fig. 5) can be made in the form of a magnetic memory block with actuation windings 16 and return 17 connected respectively via rectifiers 3 and 5 with current sensors 1 and 6 and a magnetic arrow 18 indicating the search direction.

The device works as follows.

When k. S. on the branch (see Fig. 1), at the output of DT 6, a signal appears, which through the rectifier 5 is fed to one of the inputs indi5

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triggering 4, perceiving and preserving information about

cond. Depending on the execution

DT 1 there are two possible functioning of the device.

When performing DT 1 is fast-dissipating, but having a higher sensitivity at low currents than DT 6, after switching on the line, the operation indicator 4 is reset to the initial state by a signal coming to its input through the rectifier 3 from DT 1. This return signal is provided by line load current. When k. S. in the highway behind the branching point, the trigger indicator 4 retains its original state, and when the cross section occurs, it maintains the initial state. in the branch goes to the state "The presence of a to. W. on the branch." The pointer returns to its original state after the line is turned on to work with the load current.

When performing DT 1 is the same as DT 6, i.e. unsaturated and the same sensitivity, the device does not return to its original state after the line is turned on, since the operating current under this condition cannot change the state of the trip indicator 4. The last changes its state only when k. on the branch, if before this k. it was on the highway behind the branching point and vice versa, and it stores information about the direction of the last k. s., regardless of whether it was stable or not.

Since the proposed device is intended for installation on the phase conductor of a line, in the case of a current return version, it is necessary to install it on two phase conductors, and the presence of a k. on the branch is determined by the response of at least one device. In the case of the version with the same DT, it is necessary to install (devices on each of the three phase wires, and the search direction is judged by two (or three) devices pointing in one direction.

In the device with memorizing the direction of the last c. IPT can be used as DT, which are placed as shown in FIG. 3. In this case, it is sufficient to have only one device containing two IPTs, each of which controls the current of the two wires of the line and the branches, respectively.

The operation of the device is influenced by the load currents, which have to be limited from above to ensure reliable operation of the device. To reduce the effect of the load between the rectifiers and the load indicator, differentiating units are included (see FIG. 4). Differentiating blocks, representing a capacitor with a parallel-connected resistance, pass to the inputs of the response indicator 4 only the transition component of the current k. and do not let work currents.

The trigger indicator can be made in the form of a relay element with a contact output, as well as in the form of a block of magnetic memory with windings 16 and 17 (Fig. 5) and a magnetic arrow, the movement of which in space is limited to an angle of 90 ^e . When magnetizing the magnetic memory block, the needle rotates through an angle of 90 ° and stably remains in this position due to the residual field of the magnetic system (see Fig. 5),

In one of these stable states, the arrow points along the line and points in the direction of the main line behind the branch point, while in the other it turns perpendicular to the line and points to a branch. The magnetic needle is placed in a sealed, transparent bottom of the cylinder, providing the opportunity to observe it from the ground.

The version of the device with the same unsaturated diesel fuel ensures that information on the direction of the latter is stored. H. as sustainable, and unstable and has, therefore, greater functionality.

The device does not have strict requirements for the quality of diesel fuel, so they can be made detachable, that. allows you to simply and quickly mount them to wires without them. dissection.

When performing diesel fuel in the form of IPT, the number of devices per raztetvlenk ΐ is reduced by two to three times and the device elements are not connected to the parts of the overhead line that are under voltage.

- Differentiating authorities, which allow only the transient component of the co. E. Current to the indicator input, make it possible to almost completely eliminate the influence of operating currents on the operation of the device and thereby increase its reliability and noise immunity.

The execution of the trigger indicator in the form of a magnetic memory block with an arrow provides visibility of information about the direction to. H. The arrow of the indicator shows directly the direction of movement of the brigade, which reduces to a minimum the time spent on inspecting the pointer and analyzing information.

Thus, the proposed device is simple to manufacture, install, and operate cheaply, reliably and safely.

eight

The bot does not degrade the performance of the monitored line and has more extensive functionality than the prototype device, i.e., it most fully meets the requirements of electric networks of 6-10, 5 35 kV. With a small outlay of time and money for manufacturing, installation and operation, it greatly facilitates the search for all types between phase C. E. e. <P

Claims (5)

Claim 1. A device for determining the. of the short circuit on the air line with branches, containing two current sensors, one of which is installed on the branch, the outputs of these current sensors are connected via rectifiers to the corresponding — θ to the leading inputs of the operation indicator, different that in order to extend the functionality by fixing an unstable short circuit, 25 The second current sensor is installed behind the branch point on the air line. 2. Device by π. 1, characterized in that the second 30 The sensor is designed as a non-sagging current transformer. 3. The device according to claim 1, in the case that the sensors current is made in the form of induction current transducers, with the induction current transducer in the line installed in parallel with the branch wires, and the induction current transducer in the branch is installed parallel to the main wires. 4. -Device by π. 1, characterized in that, in order to improve noise immunity, two differentiating units are inserted, connected between the outputs of the respective rectifiers and the inputs of the operation indicator. 5. Device pop. 1, characterized in that the trigger indicator is made in the form of a block of magnetic memory with an arrow.