RU115583U1 - REMOTE CONTROL OF ELECTRIC TRANSMISSION AIR LINE SUPPLIED WITH AN OPTICAL FIBER CABLE - Google Patents

Abstract

1. A device for remote control of an overhead power line equipped with a fiber optic cable, containing an optical splitter intended for connection to the fiber optic cable, to which a laser pulse shaper is connected, the first optical detector that perceives the Rayleigh backscatter component, and the second optical detector that perceives the anti-drain component of the Raman component backscatter, wherein the input of the laser pulse shaper and the outputs of the optical detectors are connected to the control and processing unit, which is configured to determine the location and intensity of acoustic and temperature effects on the fiber optic cable of the power line using the generated reflectograms. ! 2. The device according to claim 1, in which a third optical detector is additionally connected to the optical splitter, connected by the output to the control and processing unit and perceiving the Brillouin component of the backscatter, and the control and processing unit is made with the additional possibility of determining the location and intensity of mechanical damage from the generated reflectograms. impacts on the fiber optic cable of the power line. ! 3. The device according to claim 1 or 2, in which a control fiber is additionally connected to the optical splitter, equipped with a temperature sensor, the output of which is connected to the control and processing unit. ! 4. The device according to claim 1 or 2, in which the optical detectors are connected to the control and processing unit through one common or separate analog-to-digital converters, and the unit

Description

Technical field

The utility model relates to remote control (monitoring) of electric power facilities and is designed to obtain data on the threatening operation of a high-voltage overhead power transmission line (VL) due to natural or man-made origin, to present the received data on identified threats on the monitor of the VL operation control panel (for example, a dispatch panel). Among those that require control of impacts on overhead lines are, in particular, lightning discharges, explosions, top and bottom fires, short circuits (interphase or to the ground), shots through wires and linear insulation, falling trees, their branches or other objects on poles, wires or lightning protection cables, ice deposits and smelting of ice, impacts on overhead lines, which are in the nature of vandalism, sabotage or sabotage.

The monitoring results can be used to reliably and accurately detect the locations of hazardous OLs, to analyze their nature and origin, purposefully eliminate the menacing hazards themselves and eliminate their consequences, restore the normal operation of OHLs, ensure high reliability and operational readiness of network infrastructure facilities.

State of the art

VL monitoring systems are known for detecting, collecting and transmitting to a centralized control panel data on factors that threaten its normal operation.

The “Power Line Protection System” known from RU 72549 uses a variety of remote elements installed along the OHL to perform these functions, sequentially sending and receiving direct and reverse markers along the OHL wire, as well as radio communications, including GSM modems. Damage to the line is accompanied by the loss of a marker from the corresponding remote element and, due to this, is detected by the system.

Known from RU2400765 “Method for determining the location of damage to power lines and a device for its implementation” they use for sending overhead lines sending probing pulses with time-frequency modulation along overhead lines, receiving reflected pulses and comparing them with demodulated reflected signals previously received on an undamaged line.

Known from RU 2209513 "A system for transmitting signals through an electrical supply line for detecting icy deposits on wires" transmits the RF signal through the overhead wire and controls their attenuation in the wire. The attenuation increases both due to ice and due to additional load elements connected to the wire at individual points on the overhead line with an increase in attenuation at these points to specified limits.

Fiber optic systems for controlling the distribution of temperature and deformations along extended objects are also known.

Known from RU 2319988. “Fiber optic multisensor system” consists of optically coupled radiation source (laser), an optical fiber equipped with point sensors distributed along the fiber based on fiber Bragg gratings, reflecting light at different resonant wavelengths, a fiber beam splitter and a spectrum analyzer, which is the photodetector. Sensors with different reflection coefficients and / or with a different width or shape of the reflection spectrum alternate along the optical fiber in a predetermined order, including division into groups.

The “Acoustic Fiber Optic Antenna” known from RU 2234105 consists of two parallel optical fibers equipped with an emitter and a differential photodetector, in each of which fiber-optic sensors are installed with an interval equal to a half-wave of the low-frequency acoustic signal: with pre-created microbends in one channel and without microbends in another channel. This analogue requires the use of two optical fibers (optical fibers) to control one type of exposure (acoustic).

A common drawback of all the above analogues is that their application requires the installation of additional equipment along the overhead lines - sensors of controlled influences.

A fiber-optic device for controlling the distribution of temperature and deformations along extended objects is known, the use of which allows not to install sensors along the OHL, using as this “dark” (free from communication signals) fiber of the optical communication cable, which in many cases is equipped with trunk OHLs [RU 2346235] . This analogue is selected as a prototype.

The prototype is a “Distributed Fiber Optic Sensor” for monitoring acoustic and thermal influences, containing an optical pulse shaper, an optical fiber and an optical detector that receives Brillouin backscattering components.

The distance between the frequencies of the incident radiation and the Brillouin components, depending on the type of silica fiber, is 10.5-11.0 GHz. Temperature and acoustic effects on individual sections of the optical fiber change the frequency shift of the Brillouin scattering components reflected by this part of fiber 2. Moreover, both of these types of effects cause similar changes in the nature of Brillouin scattering and the separation of these changes is extremely difficult. Therefore, reliable measurements based on the Brillouin backscattering components are possible only in cases when one of the influencing factors (temperature or acoustic vibrations) does not change, and the influence of the other factor must be determined.

Due to the impossibility of reliably separating the results of acoustic effects from the results of temperature effects in the detected signal, the control carried out by the prototype is not informative enough.

When using the prototype on an overhead line equipped with a fiber optic cable, this drawback does not allow, in particular, to fully control the ice melting process on the overhead line, regulating the heating by the melting current, since the data obtained are the result of the combined influence of the wire heating temperature, acoustic stresses and mechanical deformations caused by the increase sagging wires under the action of icy deposits or other mechanical stresses.

Utility Model Disclosure

The technical result of the utility model is the possibility of independent separate control of various effects on overhead lines when using a single optical fiber as part of a communication cable.

The object of the utility model is a device for remote control of an overhead power line equipped with a fiber optic cable, comprising an optical splitter for connecting to a fiber optic cable, to which a laser pulse former is connected, a first optical detector receiving the Rayleigh backscattering component, and a second optical detector receiving the anti-drain component Raman component of backscattering, while the input of the laser pulse shaper The s and the outputs of the optical detectors are connected to a control and processing unit, which is configured to determine the location and intensity of acoustic and temperature effects on the fiber optic cable of the power line from the reflectograms generated by it.

This allows you to get the above technical result.

The utility model has development.

The first development consists in the fact that a third optical detector is additionally connected to the optical splitter, connected to the control and processing unit by an output and receiving the Brillouin backscattering component, and the control and processing unit is made with the additional possibility of determining the location and intensity of mechanical stresses from the generated reflectograms fiber optic power line cable.

This development is aimed at increasing the reliability of separate determination of the intensity of mechanical and temperature effects and the accuracy of their location on overhead lines, for example, in conditions of ice melting.

The second development consists in the fact that an optical fiber equipped with a temperature sensor, the output of which is connected to the control and processing unit, is additionally connected to the optical splitter.

This development is aimed at ensuring the binding of the temperature scale of the device to absolute temperature values to increase the accuracy of determining the intensity of various effects on overhead lines and their location,

The third development is that the optical detectors are connected to the control and processing unit through one common or separate analog-to-digital converters, and the processing unit is made in the form of one or more interfaced digital programmable devices.

This development allows us to implement a useful model on a progressive element base using programmable digital signal processing devices for the optical range.

Implementation of a utility model, taking into account its developments

Figure 1 presents a diagram illustrating the implementation of a utility model, taking into account its developments. Figure 2 schematically shows the spectral composition of the backscattering radiation in a quartz single-mode optical fiber.

An optical splitter 2 of a communication cable located on the overhead line or integrated in a lightning cable is connected to the optical splitter 1. The splitter 1 is also connected to a laser pulse shaper 3 probing the optical fiber 2, a first optical detector 4 receiving the Rayleigh backscattering component and a second optical detector 5 receiving the anti-drain component of the Raman backscattering component.

The input of the laser pulse shaper 3 and the outputs of the detectors 4 and 5 are connected to the control and processing unit 6, which is made on the basis of the processor 7 with the interface means. Based on the known attenuation characteristics and the known propagation velocity of forward and backward radiation in optical fiber 2, block 6 generates reflectograms based on the output signal of each of the detectors 4, 5 and determines the intensity of acoustic and temperature effects on the optical fiber and their place on the transmission line path from the generated reflectograms.

In addition, a third optical detector 8, which receives the Brillouin backscatter component, can be connected to the splitter 1. The output of the detector 8, as well as the outputs of the detectors 4 and 5, is connected to the block 6, which, in this case, is configured to generate and process the corresponding trace according to the output signal of the detector 8. If there are three of these detectors, block 6 can be made with additional features forming reflectograms on the output signal of the detector 8 and determining from them the location and intensity of mechanical stresses on the optical fiber 2 and, therefore, on the power line. Moreover, static (mechanical and thermal) effects are more reliably separated from each other.

To the optical splitter 1 can be connected to a control optical fiber 9, equipped with a temperature sensor 10, the output of which is connected to block 6.

Block 6 may have a common input analog-to-digital converter (ADC) 11, digitizing all the analog signals supplied to block 6 for digital processing. For alternate connection with sources of analog signals (detectors 4, 5, 8 and sensor 10), the ADC 11 is equipped with an input demultiplexer 12.

Block 6 may be made in the form of one or more interconnected digital programmable devices, including a personal computer with a display.

The proposed device operates as follows.

The shaper 3 under the control of block 6 generates laser pulses probing fiber 2. To monitor the state of long (tens of kilometers) lines, it is advisable to measure at those wavelengths where the attenuation of signals in fiber 2 is minimal - 1550 nm and / or 1625 nm.

The laser pulses of the shaper 3 through the splitter 1 is injected into the optical fiber 2. In turn, the backscattering radiation reflected from the walls of the fiber 2 passes through the splitter 1 to the optical detectors 4, 5 and 8. Each of the detectors generates a signal proportional to the corresponding backscattering component at its output . These signals through the multiplexer 12 are alternately fed to the input of the ADC 11 and - after conversion to digital code - are digitally processed in block 6.

In the setup mode, the laser pulses of the shaper 3 instead of fiber 2 are fed to the control optical fiber 9. In this case, the results of detection of backscattering in the optical fiber 9 and the temperature measurement results of this optical fiber by the sensor 10 are supplied through the multiplexer 12 and ADC 11 to the digital processing unit 6 and the temperature is linked device scales to absolute temperature values.

When a laser pulse passes through quartz optical fibers 2 or 9, the radiation partially scatters the inhomogeneities and atoms of the crystal lattice. In this case, the scattered radiation contains both components with the same wavelength as the incident radiation (Rayleigh scattering), and components with other wavelengths (Raman scattering, which is usually divided into Brillouin and Raman). The components closest to the wavelength of the incident radiation on which the prototype is based are called Brillouin. Raman scattering has two of its components. The component of the Raman scattering, which is located to the right of the Rayleigh scattering (see Fig. 2), is called the Stokes component, and the one to the left is the anti-Stokes component.

In the proposed device, the separate control of acoustic and temperature effects is based on the detection and joint processing of two backscattering components: Relay and anti-Stokes Ramanovskaya.

In a quartz single-mode optical fiber 2, the Raman scattering components are separated from the incident radiation frequency by a significant amount of the order of 13.0 THz. Therefore, for their registration in the detector 5, you can use laser diodes and optical filters, which are widely used in measuring and telecommunication equipment.

Acoustic effects on various sections of optical fiber 2 change the intensity of the Rayleigh backscattering reflected by this section and received by detector 4. The temperature effects on sections of optical fiber 2 mainly affect the intensity of the anti-Stokes component of Raman backscattering received by detector 5.

Based on the output signals of the detectors 4 and 5, block 6 forms the corresponding reflectograms reflecting the distribution of actions along the optical fiber, and therefore along the overhead line.

Comparison of reflectograms obtained from the signals at the output of detector 4 and detector 5, carried out by block 6, allows, despite the significant attenuation of the scattering radiation reflected by the optical fiber at the remote end of the overhead line, to reliably separate the temperature changes from acoustic effects throughout its length.

In the process of melting ice deposits on the wire or ground wire of the overhead line equipped with a fiber optic cable, its sag changes. The sag arrow depends on the weight of the ice and the temperature of the wire or ground wire, heated by the melting current. Bending mechanical stresses and temperature simultaneously affect the sections of optical fiber 2. In this case, it is not always possible to reliably establish from the traces obtained from the output signals of the detectors 4 and 5 what effects (temperature or mechanical stress) caused changes in these traces. At a high temperature of the wire, the melting current should be reduced, and with mechanical influences from sagging and icing, but an acceptable temperature of the wire, the melting current can be saved or even increased.

The use of additional reflectograms generated by the signals of detector 8, which independently perceives a different type of backscattering (Brillouin scattering), and conducting a comparative complex analysis of all received reflectograms in block 6, can additionally increase the reliability of a separate determination of the nature of external influences in this and in other cases.

Claims (4)

1. A remote control device for an overhead power line equipped with a fiber optic cable, comprising an optical splitter for connecting to a fiber optic cable, to which a laser pulse former is connected, a first optical detector sensing a Rayleigh backscattering component, and a second optical detector sensing an anti-drain component of the Raman component backscattering, while the input of the laser pulse former and the outputs of the optical detectors connected to the control and processing unit, which is configured to determine the location and intensity of acoustic and temperature effects on the fiber optic cable of the power line from the reflectograms generated by it. 2. The device according to claim 1, in which a third optical detector is additionally connected to the optical splitter, connected by an output to the control and processing unit and receiving the Brillouin backscattering component, and the control and processing unit is made with the additional possibility of determining the location and intensity of mechanical effects on the fiber optic cable of the power line. 3. The device according to claim 1 or 2, in which a control fiber is additionally connected to the optical splitter, equipped with a temperature sensor, the output of which is connected to the control and processing unit. 4. The device according to claim 1 or 2, in which the optical detectors are connected to the control and processing unit through one common or separate analog-to-digital converters, and the processing unit is made in the form of one or more interfaced digital programmable devices.