RU96354U1 - DEVICE FOR DETERMINING THE DEFENSE AND FIXATION OF THE DAMAGED PHASE OF THE INSULATED WIRES OF AIR LINES WITH A VOLTAGE OVER 1000 V AT THEIR LOCATION ON THE SUPPORTS OF THE AC CONTACT NETWORK - Google Patents

Abstract

 A device for determining the breakage and fixing of the damaged phase of insulated overhead line wires with voltages above 1000 V when they are located on the poles of an AC contact network, consisting of a three-phase supply transformer, the secondary high-voltage winding of which is connected through the switching device to insulated high-voltage line wires, at the beginning and end which connected measuring three-phase transformers, the secondary windings of which are connected in a triangle, and the primary - in a star, zero points through which the resistive-capacitive filter connected to the artificial earthing switches, characterized in that it further parallel phases of the secondary winding of the measuring transformer at the end of the line connected analog inputs of the microprocessor device to measure and analyze the phase and control overhead voltage measuring transformer switching device at the end of the line; at the same time, at the beginning of the line, analog inputs of the second microprocessor device for measuring and analyzing the voltage on the resistive-capacitive filter at the beginning of the line and controlling the switching device of the high-voltage power line with insulated neutral are connected in parallel with the zero-voltage filter.

Description

The utility model relates to electrical engineering, in particular, to the power supply system of non-traction consumers of electrified railways, and can be used to determine the breakage and fixing of the damaged phase of overhead lines with voltages above 1000 V with insulated neutral, which have found application for powering non-traction consumers, including high-voltage ones self-locking lines.

Known technical solutions for determining the breakage of an air wire in networks with a voltage of more than 1000 V with an isolated neutral, the principle of operation of which is based on the occurrence of voltage (L-1) or voltage and current (L-2) of zero sequences.

In L-1, a device is proposed for protecting overhead lines from single-phase earth faults of high-voltage lines with voltages above 1000 V for supplying non-traction consumers. The device is designed for lines located on the supports of the contact AC network in the areas of convergence with high-voltage power lines. It is taken as a prototype.

The prototype consists of a supply transformer, overhead line switching device, high-voltage line aerial wires, TM or TS type transformers, a measuring transformer switching unit at the end of the line, resistive-capacitive filters, artificial grounding conductors, a voltage threshold element with a preset zero sequence voltage setting at the end a line, a threshold time element with a given setting for the time of the presence of voltage of the zero sequence of a certain value at the end a line, a threshold time element with a predetermined setting for the off time of the zero-sequence voltage filter at the end of the line, a threshold element of the voltage on the filter at the beginning of the line with a specified zero-sequence voltage set-point, of a logic block. The prototype device operates as follows.

In the event of the breakdown of the insulated overhead line of the overhead line located in the zone of electromagnetic influence due to the operating voltage of the supply transformer and the installation of two resistive-capacitive filters at the beginning and end of the line included in the ground circuit of the zero points of the primary windings of the transformers, the secondary windings of which are connected in a triangle, through artificial grounding and filters flow zero current sequence. A threshold element is triggered that fixes the zero sequence voltage level and provides a signal to the threshold time element. After a predetermined time value exceeding the time for disabling the short circuit mode in the traction network, the threshold time element closes the output contact and sends a signal to turn off the switching device of the measuring transformer. Simultaneously with the shutdown command, the threshold element launches a second threshold time element, which after a certain time, gives a signal to turn on the zero-sequence voltage filter. The threshold voltage element, which measures the voltage on the filter at the beginning of the protected line, is triggered and gives a signal to the logic unit for a time equal to the length of the increase in voltage caused by the filter being turned off at the end of the line. If the set point and the length of time during which the threshold element sends a signal to the logic block coincide, a signal is sent to turn off the overhead line by the switching device.

In the event that the zero sequence voltage exceeds the threshold element setting due to the magnetic influence of currents in the traction network or power lines during short circuits, only the threshold voltage element is triggered. The threshold time element is triggered by the signal of the threshold voltage element, but does not have time to give a signal at its output due to the short duration of these modes (their duration is less than the specified time setting). The signal to turn off the overhead line will not come.

However, the known device is unable to determine which of the phases of the protected line is damaged and transmit this information to the power substation. The transfer of such information is an important and necessary feature during operation, it will greatly facilitate and accelerate the work to restore the normal full-phase mode of operation of the line and the power of its consumers.

To eliminate the above-mentioned disadvantages, it is possible to measure the phase voltage of the overhead lines at the end of the protected line and turn off the zero-sequence voltage filter for various known predetermined time intervals. The duration of each gap in this case corresponds to damage to a certain phase of overhead lines. Then, a comparison is made of the time during which the voltage measured on the filter at the beginning of the line increases. If the time coincides with one of the settings, the hazardous mode is turned off and information is displayed on the damage of a certain phase of the overhead line.

The technical result of the utility model is to increase the information content and the efficiency of the device for determining the breakage of insulated wires of overhead lines with voltages of more than 1000 V when they are located on the supports of the contact AC network, the device allows to reduce the level of electrical injuries of maintenance personnel associated with the elimination of the accident, and reduce the time for its elimination.

In the known device for determining the breakdown of insulated wires of overhead lines with voltages of more than 1000 V when they are located on the supports of the contact AC network in the areas of convergence with high-voltage power lines, consisting of a three-phase supply transformer connected to it through the switching apparatus of the overhead wires installed at the beginning and the end of two measuring transformers, the secondary windings of which are included in the triangle, and the primary windings in the star, the zero points of which are through resistive-capacitive filters with Connected to artificial grounding, the following changes are made. Instead of a threshold voltage element connected in parallel to the resistive-capacitive filter at the end of the line, to the output terminals of which are connected the input terminals of the threshold time element, the output terminals of which are combined with the input terminals of the second threshold time element, while the output terminals of both threshold time elements are included in the control circuit switching apparatus of the measuring transformer, a microprocessor device is installed. The analog inputs of a microprocessor device are connected in parallel with the phases of the low-voltage winding of the measuring transformer. The output of the device is included in the position control circuit switch of the measuring transformer.

At the beginning of the line, instead of the threshold voltage element present in the prototype device, connected in parallel with the zero sequence voltage filter, the output terminals of which are connected to the input terminals of the logic unit, the output terminals of which are included in the control circuit of the switching device that disconnects the supply transformer, a microprocessor device is also connected. In this case, its measuring analog input is connected in parallel with the zero-sequence voltage filter, and the output is connected to the control circuit of the overhead switching device.

The claimed utility model is illustrated in figure 1.

Figure 1 marked:

1 - feeding three-phase transformer;

2 - switching apparatus VL (high voltage switch, vacuum switch, etc.);

3 - overhead wires of a high voltage line;

4 - primary high-voltage winding of a transformer of the type TM or TS installed at the beginning of the protected line;

5 - secondary low-voltage winding of a transformer installed at the beginning of the protected line;

6 - resistive-capacitive filter installed at the beginning of the protected line;

7 - resistive-capacitive filter installed at the end of the protected line;

8 - primary high-voltage winding of a transformer of type TM or TS, installed at the end of the protected line;

9 - secondary low-voltage winding of a transformer installed at the end of the protected line;

10 - artificial ground electrode at the beginning of the line;

11 - artificial ground electrode at the end of the line;

12 - microprocessor device at the end of the line;

13 - firmware module of a microprocessor device at the end of the line, which measures the phase voltage of the overhead line;

14 - firmware module of a microprocessor device at the end of the line, performing continuous analysis of the voltages measured by block 13;

15 - firmware module of a microprocessor device at the end of the line, which controls the switching device of the measuring transformer;

16 - switching apparatus of the measuring transformer at the end of the line;

17 - microprocessor device at the beginning of the line;

18 is a hardware-software module of a microprocessor device at the beginning of the line that measures the voltage at the zero-sequence voltage filter;

19 is a hardware-software module of a microprocessor device at the beginning of the line, performing continuous analysis of the voltage measured by block 18;

20 is a hardware-software module of a microprocessor device at the beginning of the line, which compares the time of presence of an increased voltage on a resistive-capacitive filter with the settings;

21 - firmware module of a microprocessor device at the beginning of the line, which displays information about the damaged phase;

22 - firmware module of a microprocessor device at the beginning of the line, which controls the switching device of the overhead line.

The proposed device for determining the breakage and fixing the damaged phase of the insulated wires of overhead lines with a voltage of more than 1000 V when they are located on the supports of the contact AC network operates as follows.

When the insulated air wire (3) of the overhead line breaks, a significant decrease in one of the phase voltages of the overhead line at the end of the line occurs. The firmware module (13) of the microprocessor device (12), which continuously measures the three phase voltages of the overhead lines, transmits the measurement information to the analysis module (14), which, in turn, compares the obtained values of the phase voltages with the nominal and, in the case of a sharp reducing one or more of them, forms the corresponding data packet at its output. This information is transmitted to the control module of the switching device of the measuring transformer at the end of the protected line (15). He gives a command to open the circuit breaker (16) and, after a certain period of time, corresponding to the value set for the damaged phase, switches the circuit breaker on.

Turning off the filter at the end of the line causes an increase in the voltage at the filter at the beginning of the overhead line, which is measured by the module (18) of the microprocessor device installed at the beginning of the line (17). Module (19) receives information from module (18) and, in the case of an increase in the measured voltage, transmits a signal about the time of its presence on the resistive-capacitive filter to module (20). It compares this time with three pre-set values, each of which corresponds to a break in one of the phases of the overhead line. If the time coincides with one of the settings, the module gives a signal to the modules (21) and (22). Module (21) is designed to display information about the damaged phase. The conclusion can be made both to a special display or display panel, and to the environment of the industrial control system. It is possible both in the form of three discrete outputs (“dry pair”), one for each of the OHL phases, and using the RS-485 protocol.

Upon receipt of the signal, the module (22) issues a command to turn off the switching device of the overhead line (2).

In those cases when a decrease in phase voltage at the end of the line occurs to a level exceeding the setting, or an increased voltage level at the filter at the beginning of the line is present for a period of time other than three settings, the line will not be switched off.

The proposed device for determining the breakdown of insulated wires and fixing the damaged phase of overhead lines with voltages above 1000 V when they are located on the supports of the contact AC network allows you to tune out from the electromagnetic influence of the traction power supply system, to ensure reliable disconnection and determination of the damaged phase of overhead lines, the wires of which are insulated.

The device also works reliably in case of breakdown of non-insulated OHL wires when they fall to the ground, including when the wire-to-ground transition resistance is significantly higher than the resistive-capacitive phase resistance relative to the ground, which occurs in areas with rocky and permafrost soils.

Sources of information taken into account when compiling the description.

1. A device for determining the breakage of insulated wires of overhead lines with a voltage of more than 1000 V when they are located on the supports of the contact AC network in the areas of convergence with high-voltage power lines. Authors: Kosarev A.B., Kuznetsov D.G., Moskvin S.L. Utility Model Patent No. 87967, May 22, 2009 - 2 pp. (prototype)

2. Serov V.I., Shutsky V.I., Yagudaev B.M. Methods and means of combating earth faults in high-voltage systems of mining enterprises. - M .: Nauka, 1985.-136 p.

Claims (1)

A device for determining the breakage and fixing of the damaged phase of insulated overhead line wires with voltages above 1000 V when they are located on the poles of an AC contact network, consisting of a three-phase supply transformer, the secondary high-voltage winding of which is connected through the switching device to insulated high-voltage line wires, at the beginning and end which connected measuring three-phase transformers, the secondary windings of which are connected in a triangle, and the primary - in a star, zero points through which the resistive-capacitive filter connected to the artificial earthing switches, characterized in that it further parallel phases of the secondary winding of the measuring transformer at the end of the line connected analog inputs of the microprocessor device to measure and analyze the phase and control overhead voltage measuring transformer switching device at the end of the line; at the same time, at the beginning of the line, the analog inputs of the second microprocessor device for measuring and analyzing the voltage on the resistive-capacitive filter at the beginning of the line and controlling the switching device of the high-voltage power line with isolated neutral are connected to the zero-voltage filter.