RU185831U1 - STORM DEVICE FOR REGISTRATION OF THUNDER DISCHARGES AND PLACES OF DAMAGE TO INSULATION ON VL - Google Patents

Abstract

The utility model relates to the electric power industry and can be used to quickly obtain information about thunderstorm conditions and the intensity of thunderstorm activity on the routes of high-voltage overhead power transmission lines (VL), including branches.

The device for registering lightning discharges on the overhead line contains a lightning surge detector, the recorder is equipped with an accurate time signal receiver and is configured to record the current time and record the output signal of the corresponding sensor into digital form, the recorder is connected to a lightning surge sensor, characterized in that the sensor represents consists of three current transformers installed in the grounded circuits of isolation capacitors connected between the device I ( "earth") and the corresponding phase conductor at the end of the overhead line or at the end of its branches, the secondary windings of the current transformers are connected to the input of the recorder.

EFFECT: increased accuracy of determining the type and parameters of an event such as a lightning strike in high-voltage power lines is achieved by using a sensor of three current transformers, which allows to obtain more relevant information about events in the network. 3 s.p. f-ly, 2 ill.

Description

The utility model relates to the electric power industry and can be used to quickly obtain information about thunderstorm conditions and the intensity of thunderstorm activity on the routes of high-voltage overhead power transmission lines (VL), including branches.

The well-known "Method for determining the location of a single-phase earth fault in a branched overhead power line, the method for determining the location of a phase-phase short circuit in a branched overhead power line and a device for monitoring current and voltage for their implementation" RU 2372624 [2], which consists in fixing the time of arrival the leading edge of the pulse, at the beginning of the power line and at the end of each branch, devices for monitoring current and voltage are installed on the wires of the high-voltage power line, the number of which is one more than the number of control branches, use the phase voltage jump as pulses, simultaneously all the devices record the time of the phase voltage jump in a single time scale, synchronized from the satellite signals of the global positioning system, transfer the registered times to the control center for their automatic processing, where for fixed times from each pairs of devices for monitoring current and voltage by the differential-range measuring method determine the damaged branch, and for fixed time a pair of current control devices and the voltage, one of which is located on the affected branch rangedifference determine fault location method on that branch.

The disadvantage of this device is the inability to automatically accurately determine the coordinates of the event, for example, a lightning strike, in a branched three-phase network.

The closest technical solution is the "Lightning discharge monitoring system on overhead power lines with improved selectivity and accuracy of determining the location of a lightning discharge" RU PM 153360 [1], containing lightning surge detectors installed at the ends of the monitored line, each of the recorders is equipped with an accurate time signal receiver and made with the possibility of fixing the values of the current time and recording with digitization of the output signal of the corresponding sensor, each reg the istrator is connected to the corresponding lightning surge sensor.

The device allows you to automate the processing of information.

The disadvantage is the low accuracy of determining the type of event and the low accuracy of determining the coordinates of an event, for example, a lightning discharge. An additional drawback is the inability to determine the exact parameters of the event in high-voltage lines with branches.

The technical result of the invention is to increase the accuracy of determining the type and parameters of events such as lightning strike in high voltage power lines.

The technical result is achieved by the fact that the device for recording lightning discharges on an overhead line containing a lightning surge recorder (installed at the end of the monitored line), the recorder is equipped with an accurate time signal receiver and is configured to record the current time values and record the corresponding output signal into digital form sensor, the recorder is connected to the corresponding lightning surge sensor, characterized in that the sensor consists of three transformers current installed in the grounded circuits of isolation capacitors connected between the grounding device (ground) and the corresponding phase wire at the end of the overhead line or at the end of its branch, the secondary windings of current transformers are connected to the input of the recorder.

The device may contain three comparators comparing each of the three output signals of the sensor with a given threshold, which will allow you to respond to an event that occurs in any of the overhead lines.

The registrar may contain a protection unit, connected between the secondary winding of the current transformer and the input of the registrar, which will protect the controllers from failure when exposed to a large amplitude pulse from the sensor.

The device may contain a unit for comparing all three signals from the (three-phase) sensor, which will clarify in which phase wire the event occurred.

The device is schematically shown in FIG. 1 (sensor and controller circuit), in FIG. 2 (scheme of overhead lines with branches), where:

1 - sensor No. 0;

2 - sensor No. 1;

3 - sensor No. 2;

4 - sensor No. 3;

5 - phase wire (end of the monitored line);

6 - isolation capacitor;

7 - current transformer;

8 - input protection block;

9 - receiver of accurate time signals;

10 - communications;

11 - power supply unit of the registrar;

12 - section "a";

13 - section "b";

14 - section "c";

15 - section "d";

16 - section "f".

The implementation of the method is described by the example of the network fragment shown in FIG. 2. The fragment is an overhead line with two branches, to transformer substations equipped with sensors 2 and 3 (sensors No. 1 and No. 2, respectively) with outgoing from the power distribution substation equipped with sensor 1 (RP, sensor No. 0) to the transformer substation, equipped with a sensor 4 (sensor No. 3).

The OHL sections with branches are designated 12, 13, 14, 15, 16 as “a”, “b”, “c”, “d” and “f”, respectively. For simplicity, these letters also indicate below the electric lengths of the corresponding sections, measured by the propagation time of the electromagnetic wave (in microseconds).

In FIG. 1 shows a diagram of one of the recorders with an electromagnetic disturbance sensor. The sensor consists of three current transformers 7 installed in the grounded circuits of isolation capacitors 6 connected between the "ground" (grounding device) and the corresponding phase wire 5 at the end of the overhead line or at the end of its branch. The secondary windings of current transformers are connected to the protection unit 8, which, in turn, is connected to the input of the recorder. The protection unit performs the functions of filtering (together with the corresponding isolation capacitor), surge protection. The recorder includes a comparator comparing each of the three sensor output signals with a given threshold. The recorder includes a receiver of accurate time signals 9 from a satellite navigation system (GPS and / or Glonass), equipped with an antenna. The recorder includes communication means 10 (via GSM antenna A2 and / or “LAN” port) with a centralized processing server located, for example, at a substation supplying overhead lines. The recorder power supply is shown in pos. eleven.

In the absence of damage and thunderstorms, currents through isolation capacitors induce signals at the outputs of current transformers whose magnitude does not exceed a predetermined threshold.

In the event of damage or thunderstorm exposure, an electromagnetic wave arises at the site of damage or thunderstorm exposure on the overhead line or its branch, the front of which propagates along the overhead lines and reaches the ends of the overhead line and its branches at moments Ti, where i is the number of the corresponding end 0 ÷ 3.

When the wave front reaches the end at which the corresponding sensor is installed, the currents flowing from the line wires through the isolation capacitors induce signals at the transformer outputs and the recorder inputs at least one of which exceeds a predetermined threshold.

If a predetermined threshold is exceeded by at least one of the three input signals, the BS unit generates an impulse to the processing unit. The processing unit captures the moment of arrival of the impulse from the BS unit in the universal world time scale, which is linked to using the signal receiver of the satellite navigation system, and sends a message containing the fixed value of the single time (time stamp) and the corresponding value of i to the server.

Further processing of data received by the server can be performed as follows.

The centralized information processing unit, having received N messages from all registrars, calculates all possible differences Ti-Tj and generates from them a matrix of the recorded event of size N * N. This matrix is compared with matrix templates of events that were previously calculated for cases of electromagnetic disturbance in each of the N + 1 sections of overhead lines with branches and stored in the server memory.

Each matrix-template of events can be represented in the form of a table of size N × N, where N is the number of registrars. The values of the difference in the time of arrival of the electromagnetic disturbance wave at the registration points, determined by the electric lengths in microseconds of the OHL sections located between the registrars indicated in the corresponding column numbers and row numbers of the template matrix, are entered into the table cells. The cells of the table related to the registrar adjacent to the damaged section of the overhead line are not filled, since the difference in the time of registration of events in it with respect to other registrars is a priori unknown. For each section of overhead lines in which damage may occur, a template is drawn up.

Examples of template matrices for cases of damage in sections “a”, “d” and “f” of the overhead line with branches shown in FIG. 1 are presented in the form of tables 1 ÷ 3. Similarly, template matrices can be formed for damage cases in the other three (in this example) areas.

The comparison of the matrix of the registered event with the matrix templates of the events stored in the server’s memory consists in comparing the contents of the filled cells of the matrix template with the contents of the corresponding matrix cells of the registered event.

By the coincidence of the values, in at least two cells of the matrices being compared (with an error of up to 2 μs), a template matrix is determined that is closest to the matrix of the recorded event and the corresponding damaged area.

On the identified damaged section of the overhead line, the distance to the place of damage (the place of occurrence of the electromagnetic wave) is calculated by the formula:

where L _P is the length of the overhead line, T _P is the known travel time of the electromagnetic wave from the supply end of the overhead line to the end of the damaged branch, ΔT _P-0 is the difference recorded by the respective recorders.

The recorders installed on the supply ends of the overhead lines can be equipped with means for fixing (over several periods of industrial frequency) the shape of the phase signals coming from three current transformers to the BZ unit.

Theoretical studies, mathematical modeling and experiments have shown that the appropriate processing of information received from the above-described electromagnetic disturbance sensors made in the form of three current transformers installed in the grounded circuits of isolation capacitors connected to the phase wires at the ends of the overhead lines and its branches allows you to accurately determine the place of occurrence of the electromagnetic wave (as a result of damage or lightning), as well as (with appropriate analysis signals from current transformers) determine the nature of the damage (single-phase short-circuit, interphase short-circuit, wire break).

EFFECT: increased accuracy of determining the type and parameters of an event such as a lightning strike in high-voltage power lines is achieved by using a sensor of three current transformers, which allows to obtain more relevant information about events in the network. Accounting for branch calculations in a particular network will further increase the accuracy of determining the type and parameters of an event.

Industrial applicability. The utility model can be successfully applied in the production of event monitoring systems, including lightning discharges on overhead power lines.

Claims (4)

1. A device for registering lightning discharges on an overhead line containing a lightning surge recorder, the recorder is equipped with an accurate time signal receiver and is configured to record the current time and record digitally the output signal of the corresponding sensor, the recorder is connected to a lightning surge sensor, characterized in that the sensor consists of three current transformers installed in the grounded circuits of isolation capacitors connected between the ground device tions and the corresponding phase conductor at the end of the overhead or at the end of its branches, the secondary windings of current transformers connected to the input of the recorder. 2. The device according to claim 1, characterized in that it contains three comparators comparing each of the three sensor output signals with a given threshold. 3. The device according to p. 1, characterized in that it contains a protection unit connected between the secondary winding of the current transformer and the input of the recorder. 4. The device according to p. 1, characterized in that it contains a unit for comparing all three signals from the sensor.

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