SU754332A1 - Device for ranging damage location in power transmission line - Google Patents

Description

The invention relates to electrical engineering and is intended for automatic and semi-automatic determination of the distance from the location of damage to power lines, the control of the presence of short-circuits before switching on the line. ^five

A device consisting of synchronizing and probing pulses generators, start-up units, a beam of a cathode ray tube (CRT) and scale marks and an amplifier of reflected pulses is known, the formation shaping unit of the process recording time is turned on so that its input is connected to the device start-up unit and the output connected to the input of the clock generator and a modulator,

CRT with dark string

A disadvantage of the device is that the impulse response of the line to proactive za- _m CRT screen and must decode the operating personnel. The change in attenuation of the high-voltage line leads to the appearance on the screen of a CRT

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additional pulses, which makes it more difficult to decipher the readings.

The closest in technical essence to the present invention is a device for measuring the distance to the fault in the power line, containing a control unit for the presence of voltage in the line, a control unit, the first output of which is connected to a generator of probe pulses, the output of which is connected to the inputs of the connection unit and the receiver which is connected to the first input of the pulse accumulation unit and the first input of the threshold level generation unit, the second input of which is connected to the second output of the control unit and the output with the first input of the first comparison unit, the second input of which is connected to the first output of the pulse accumulation unit, the control input of which is connected to the third output of the control unit, and the output is connected to the maximum selection unit, the first display unit [2].

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The disadvantage of this device is the low accuracy of the measurement.

The purpose of the invention is to increase the reliability of the measurement.

It is achieved by the fact that the control unit, the first output of which is connected to a probe pulse generator, the output of which is connected to the inputs of the connection unit and the receiver, whose output connected to the first input of the pulse accumulation unit and the first input of the threshold level generation unit, the second input of which is connected to the second output of the control unit, and the output to the first input of the first unit comparison, the second inlet of which is connected to the first output of the pulse accumulation unit, the control input of which is connected to the third output of the control unit, and the output is connected to the maximum selection unit, the first display unit, the second comparison unit, the heterogeneity control unit, the programming unit, the memory unit, the switch, the first and second elements' Prohibition ", the first and second elements OR, the element AND, the element NOT, the second display unit, and the output of the first comparison unit is connected to the first input of the first element, the output of which is connected not with the input of the element NOT, the second input of the first element "Inhibit" and the input of the programming unit, the first output of which is connected through the first element OR to the input of the control unit and the second output to the control input of the switch, the other input of which is connected to the input of the maximum selection unit , the output of which is connected to the first input of the second element "Prohibition", the output of which is connected to the input of the first display unit and the first output of the second comparison unit, the second output of which is connected to the first input of the second OR element, the second in the stroke of which is connected to the output of the element is NOT, and the output is connected to the second input of the second element "Prohibition" and the first input of the element I, the output of which is connected to the input of the second display unit, and the second input of the element I is connected to the output of the control unit for the presence of voltage in the line the first output of the switch is connected to the first input of the second comparison unit, the second input of which is connected to the output of the memory block whose input is connected to the second ¹ output of the switch.

The drawing shows a block diagram of the device.

₅ It contains a transmission line 1, an attachment system 2 containing a coupling capacitor, an attachment filter and a high-frequency cable, a voltage presence monitoring unit 3 (CNI), a signal

U at the output of which appears in the presence of linear voltages and the absence of a zero-sequence voltage, control unit 4, designed to form a sequence of pulses synchronizing the operation of the probe pulse generator, the accumulation unit and the threshold level generation unit, the probe pulse generator 5, the receiver 6 producing filter ²⁰ tion, detection and amplification of pulses arriving through system 2 from the line, block. 7 accumulation of pulses, in which the summation of the reflected pulses coming in. receiver in

²⁵ the same time interval - one of the time intervals, into which the time interval between the moment of sending each sounding pulse and the arrival of a pulse is reflected is divided -

^30th from the end of the line, the first comparison unit 8, which allows comparing the level of pulses accumulated in block 7 with a threshold level, block 9 forming a threshold level that forms a threshold level 35 taking into account the level of interference coming from the line, maximum selection unit 10 selecting a section with the maximum level of the reflected signal, the first block 11 of the display, indicate -

^{4, the} distance to the fault location, the programming unit 12, which controls the switch and starts the control unit. With this unit can be implemented two programs ⁴⁵ we: a) memorizing information, followed by a cyclic update information at a predetermined time interval; b) memorization of information obtained when probing damaged

5θ line, and comparing it with the subsequent information obtained after the automatic reclosing cycle (AR). The device also includes the second unit 13 comparison, producing

⁵⁵ comparison of the level of impulses accumulated in accumulation unit 7, with the level of impulses accumulated during previous or subsequent sounding of the line, unit

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14 memory, storing information coming from accumulation unit 7, com, mutator 15, inhomogeneity control unit 16, determining correspondence of the number of the area where the accumulated signal level exceeded the threshold number to the allocated number, first 17 and second 18 "Ban" elements , the first 19 and second 20 elements OR, element 21 I, element 22 NOT, the second block 23 of the display.

The power transmission line 1 is connected via an accession system 2 to the output of the generator 5 probe pulses and the input of the receiver 6. The outputs of the control unit 4 are connected to the corresponding inputs of the generator 5, the pulse accumulation unit 7 and the driver 9 of the threshold level. The signal input unit 7 is connected to the output of the receiver 6, and the first ²⁰ its output output is connected to one of the inputs of the first comparison unit 8, the second input of which is connected to the output of the unit

9 forming the threshold level. The second output of the accumulation unit 7 is connected ²⁵ to the inputs of the maximum selection block 10 and the switch 15, the control input of which is connected to the first output of the programming unit 12. The first output of the switch 15 is connected to the input of the memory block ³⁰ 14 and the second output to the first input of the second block 13 comparison, the second input of which is connected to the output of the block 14, the first output of the block 13 is connected to the input of the display unit 11, the second ³⁵ output of the block 13 is connected through the first element 19 OR to the first input of the element 21 AND, and to the control input of the second element 18 "Ban" wasp new

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the input of which is connected to the output of the unit

10 select the maximum, and the output is connected to the input of the display unit 11, which is also connected to the output of the first element 17 "Prohibition", the main input of which is connected to the output of the block 8 compare-

. and the control input with the output of the heterogeneity control unit 16, which is also connected to the input of the programming unit 12 and the input of the element 22 NOT. The output of the first block 8 of the comparison is connected to the input of the block 16 control inhomogeneities. Item exit

22 is NOT connected to the second input of element 19 OR. To the second input of the element 21 And connected to the output of the unit 3 control the presence of voltage, and the output of the element 21 is connected to the second display unit 23. The output of the programming unit 12 through the second element 20 OR connected to the input of the control unit 4, while the second input of the element 20 is connected to the relay line protection.

The device works as follows.

At the command of devices for selective relay protection of the damaged line 1, the control unit 4 supplies a signal to the generator input 5 probe pulses. The generator 5 generates a series of probe pulses, which through the connection system 2 enters the damaged line 1. The impulses reflected from the fault site and inhomogeneities of the overhead lines return to the beginning of the line and together with the interference come through the connection system 2 to the receiver 6, where they are filtered, amplified and detected. From the output of the receiver 6, the pulses are received in block 7 of the accumulation of pulses. Block 7 accumulation of pulses summarizes the pulses passing from each section of the high-voltage line, for example, from the place of damage during the sensing line. Accumulated at each site, the pulses are received in block 8 comparison, where they are compared with the threshold level produced by the block 9 forming the threshold level.

The sections of the high-voltage line on which there are irregularities are considered to be selected, the rest are unselected.

Information about exceeding the threshold level at any site is fed to the input of the first element "Ban" and block 16 control inhomogeneities. Exceeding the threshold level in one of the unselected areas indicates the presence of damage on it, and the distance to it is indicated in the display unit 11 by the command of the comparison unit 8. When the threshold level is exceeded at one of the selected sections, the block неδ of heterogeneity control, at the command of block 8, prohibits the operation of block 11 and sends a command to the programming unit 12. In accordance with a given program, block 12 may:

a) switch the switch 15 to the input of the second comparison unit 13 and compare the obtained levels of accumulated pulses from the selected areas with the levels of accumulated signals from the same sections recorded earlier in block 14 of memory. Recording is made by ko7

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Manda block 12 of the control program after a specified time interval;

g) switch the switch 15 to the input of the memory block 14, and record information about the allocated areas in the memory block 14;

c) to re-enable the control unit 4 after a specified period of time (necessary for the automatic reclosing of the automatic reclosing and disconnecting the line in case of unsuccessful reclosing), compare the obtained information with the one recorded during the first measurement in the second comparison unit 13.

At the same time, if the line is successfully turned on again, the level of accumulated signals will be lower when it is switched on again than it was at the first response, similarly, when comparing the received information with the recorded one, a damaged section will be detected during sounding of the intact line, since the signal will be higher if there is damage. The distance to the site will be ²⁵ fixed in block 11 of the display.

However, in case of a deaf short circuit, it may be that the levels of the reflected signals from the selected areas will be the same during the first and repeated 30 probes. In this case, information from the maximum selection block 10 (in the presence of a signal from element 22) through the second element 17 "Ban" enters block 11. In that case, if after 35 successful switching on again, the signal level lines will appear in both measurements, the device It also indicates the distance to the section with the maximum level of the reflected signal and, at the command of the voltage presence monitoring unit 3, element 21 And switches on the second display unit 23. Turning on this block means that the probability of correct detection of the damaged section is lower than that well

The proposed device allows to increase the reliability of the correct measurement on lines with inhomogeneities due to additional processing of information coming from sites with heterogeneities. The interpretation of indications of the display unit is simplified, since the device has a digital indication and the probability of false measurements decreases.

The device can be widely used on high-voltage lines with a voltage of 330 kV and above, especially on lines with discontinuities.

Claims (1)

Claim A device for determining the distance to the fault in the transmission line, containing a control unit for the presence of voltage in the line, a control unit, the first output of which is connected to a probe pulse generator, the output of which is connected to the inputs of the connection unit and the receiver, the output of which is connected to the first input of the pulse accumulation unit and the first input of the threshold level generation unit, the second input of which is connected to the second output of the control unit, and the output to the first input of the first comparison unit, the second input to Secondly, it is connected to the first output of the pulse accumulation unit, the control input of which is connected to the third output (control unit), and the output is connected to the maximum selection unit, the first display unit, different in that, in order to increase the measurement accuracy, a second comparison unit is entered into it , inhomogeneity control unit, programming unit, memory unit, switch, first and second "Prohibition" elements, first and second OR elements, AND element, NOT element, second display unit, with the output of the first comparator unit connected to with the input of the first "Prohibition" element and the input of the heterogeneity control unit, the output of which is connected to the input of the element NOT, the second input of the first element "Prohibition" and the input of the programming unit, the first output of which is connected through the first element OR to the input of the control unit and the second output with the control input of the switch, another input of which is connected to the input of the block; selection of the maximum, the output of which is connected to the first input of the second element, the output of which is connected to the input of the first display unit and the first output of the second block with The second output of which is connected to the first input of the second OR element, whose input is connected to the output of the NO element, and the output is connected to the second input of the second Inhibit element, and the first input of the And element whose output is connected to the input of the second display unit, and the second input element AND 754332 ten [connected to the output from the control unit | presence of voltage in the line, the first output of the switch is connected to the first input of the second comparator, the second input of which is connected to the output of the memory block whose input is connected to the second output of the switch.