A high-voltage power tower settlement monitoring system based on FBG

Abstract

The present invention proposes a high-voltage power tower settlement monitoring system based on FBG, which uses a sensor based on fiber Bragg grating to monitor the settlement of the high-voltage power tower. It is not affected by the electromagnetic field of the high-voltage cable and can maintain high data integrity and stability in a high electromagnetic interference environment. A wavelength division multiplexer is used to demodulate the fiber Bragg grating optical signal to improve the measurement accuracy. Multiple groups of fiber Bragg gratings with different optical powers are used for monitoring, which can well reduce the influence of a single optical fiber signal noise signal and ensure the accuracy of the signal. In addition, the use of optical fiber transmission can well physically isolate the signal, which cannot be easily eavesdropped or intercepted, providing higher security and making it difficult for the transmitted information to be leaked.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-voltage power tower settlement monitoring, and in particular relates to a high-voltage power tower settlement monitoring system based on FBG. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] During the power transmission process, the stability of high-voltage power towers is crucial to ensure the safety and reliability of power transmission. However, due to various factors, such as changes in the natural environment and changes in power load, high-voltage power towers may sink. The sinking may cause the tower to deform, damage the structure, or even collapse, which seriously threatens the stability and safety of power transmission.

[0004] In order to monitor the settlement of high-voltage power towers in real time, traditional monitoring methods usually use physical sensors such as inclinometers, strain gauges, etc. However, these sensors need to contact or be directly installed on the power towers, which makes installation and maintenance difficult and is easily affected by harsh environments such as high temperature, high humidity, and corrosion. In addition, there are certain limitations in the data collection and transmission of traditional sensors.

[0005] In recent years, the development of fiber grating (FBG) technology has provided a new solution for the settlement monitoring of high-voltage power towers. FBG is a sensor based on optical fiber, which can measure physical quantities such as stress, temperature and strain by using the grating structure in the optical fiber to perform frequency selective reflection of optical signals.

[0006] The FBG-based high-voltage power tower settlement monitoring system uses fiber Bragg gratings as sensors, and arranges multiple fiber optic sensors on high-voltage power towers and high-voltage cables. By monitoring the spectral changes of the fiber gratings, the settlement of the power tower and the deformation of the tower can be obtained in real time. Compared with traditional sensors, the FBG-based system has the advantages of easy installation, strong anti-interference ability, and remote monitoring.

[0007] However, the current FBG technology-based devices for high-voltage power tower settlement monitoring have the problem of low measurement accuracy. Summary of the invention

[0008] In order to overcome the shortcomings of the above-mentioned prior art, the present invention provides a high-voltage power tower settlement monitoring system based on FBG, which uses sensors composed of multiple groups of fiber Bragg gratings, wavelength division multiplexers and avalanche diodes for high-voltage power tower settlement monitoring to improve the monitoring accuracy.

[0009] To achieve the above object, the first aspect of the present invention provides a high-voltage power tower settlement monitoring system based on FBG, comprising: a sensor module and a data processing unit; the sensor module comprises: a broadband spectrum transmitter for providing an excitation spectrum;

[0010] A multi-branch coupler, used to split the excitation spectrum of the broadband spectrum emitter into a plurality of optical signals with different optical powers;

[0011] A plurality of groups of fiber Bragg gratings, each group of fiber Bragg gratings is connected to different high-voltage electric cables; the plurality of groups of fiber Bragg gratings are respectively used to receive a plurality of optical signals with different optical powers output by the multi-branch coupler;

[0012] A wavelength division multiplexer, used for combining the optical signals reflected by the multiple groups of the fiber Bragg gratings into a composite optical signal;

[0013] an avalanche diode, used to receive the composite optical signal combined by the wavelength division multiplexer, and convert the composite optical signal into a corresponding analog electrical signal;

[0014] The data processing unit is used to perform analog-to-digital conversion and analysis on the analog electrical signal converted by the avalanche diode to obtain the settlement detection result of the high-voltage power tower.

[0015] One or more of the above technical solutions have the following beneficial effects:

[0016] In the present invention, a sensor based on a fiber Bragg grating is used to monitor the settlement of a high-voltage power tower. It is not affected by the electromagnetic field of the high-voltage cable and can maintain high data integrity and stability in a high electromagnetic interference environment. A wavelength division multiplexer is used to demodulate the fiber Bragg grating optical signal to improve the measurement accuracy. Multiple groups of fiber Bragg gratings with different optical powers are used for monitoring, which can well reduce the influence of the noise signal of a single optical fiber signal and ensure the accuracy of the signal. In addition, the use of optical fiber transmission can well physically isolate the signal, which cannot be easily eavesdropped or intercepted, providing higher security and making the transmission information less likely to leak. The avalanche diode has the characteristics of high gain and fast response, which can achieve high-sensitivity detection of multiple weak optical signals in the system after long-distance optical fiber transmission and proportional amplification of the signal strength of different optical fibers, thereby preventing the disappearance of signals in low-power optical fibers or optical signal crosstalk caused by different light intensities of different optical fibers.

[0017] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0019] Figure 1 This is a schematic diagram of the connection of a high-voltage power tower settlement monitoring system device based on FBG in the first embodiment of the present invention;

[0020] Figure 2 Schematic diagram of the internal connection of a 2x4 coupler in a multi-branch coupler and the proportional distribution of optical power in Embodiment 1 of the present invention;

[0021] Figure 3 This is a schematic diagram of a sensor housing in Embodiment 1 of the present invention;

[0022] Figure 4 This is a schematic diagram of a conductor or optical fiber wound around a high-voltage electric wire in Embodiment 1 of the present invention;

[0023] Figure 5 Schematic diagram of the position of each grating in a Bragg grating group on a cable optical fiber in Embodiment 1 of the present invention;

[0024] Figure 6 Schematic diagram of the position of each grating in the Bragg grating group on the optical fiber of the tower body in the first embodiment of the present invention;

[0025] Figure 7 This is a schematic diagram of the cable optical fiber result in Example 1 of the present invention;

[0026] Figure 8 This is a schematic diagram of the optical fiber results of the tower body in Example 1 of the present invention;

[0027] In the figure, 1. circuit board, 2. sensor module, 3. broadband LED light source, 4. multi-branch coupler, 5. wavelength division multiplexer, 6. avalanche diode, 7. A / D processor, 8. fiber Bragg grating, 9. data processing computer, 10. casing, 11. power module, 12. current conditioner, 13. wire. DETAILED DESCRIPTION

[0028] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0029] It should be noted that the terms used herein are for describing specific embodiments only and are not intended to be limiting of exemplary embodiments according to the present invention.

[0030] In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0031] Embodiment 1

[0032] This embodiment discloses a high-voltage power tower settlement monitoring system based on FBG, including: a sensor module and a data processing unit; the sensor module includes:

[0033] A broadband spectrum emitter for providing an excitation spectrum;

[0034] A multi-branch coupler 4, used to split the excitation spectrum of the broadband spectrum emitter into a plurality of optical signals with different optical powers;

[0035] A plurality of groups of fiber Bragg gratings 8, each group of fiber Bragg gratings 8 is respectively connected to different high-voltage electric cables; the plurality of groups of fiber Bragg gratings 8 are respectively used to receive a plurality of optical signals with different optical powers output by the multi-branch coupler;

[0036] A wavelength division multiplexer 5, used for combining the optical signals reflected by the multiple groups of the fiber Bragg gratings 8 into a composite optical signal;

[0037] an avalanche diode 6, for receiving the composite optical signal combined by the wavelength division multiplexer 5, and converting the composite optical signal into a corresponding analog electrical signal;

[0038] The data processing unit is used to perform analog-to-digital conversion and analysis on the analog electrical signal converted by the avalanche diode to obtain the settlement detection result of the high-voltage power tower.

[0039] Combine the following Figure 1 A high-voltage power tower settlement monitoring system based on FBG in this embodiment is described in detail, and specifically includes: a circuit board 1, a sensor module 2, a data processing computer 9, a housing 10, and a power module 11.

[0040] Among them, the sensor module 2 is integrated on a circuit board 1, and then connected to a data processing computer 9; the circuit board 1 is installed and fixed in a shell 10, and the fiber Bragg grating 8 partially extends out of the shell 10 and adheres to different high-voltage cables on the same path; the shell 10 is installed at the data processing computer 9.

[0041] The sensor module 2 includes a broadband spectrum transmitter, a multi-branch coupler 4 , a wavelength division multiplexer 5 , an avalanche diode 6 , an A / D processor 7 and a fiber Bragg grating 8 .

[0042] In this embodiment, the broadband spectrum emitter adopts a broadband LED light source 3 .

[0043] The broadband LED light source 3 is an important component in the high-voltage power tower settlement monitoring system device and is installed at the front of the sensor assembly. LED stands for light-emitting diode, which is a semiconductor device that can convert electrical energy into visible light. In this embodiment, the broadband LED light source 3 is used as a broadband spectrum emitter to provide excitation light for the fiber Bragg grating 8.

[0044] In the high-voltage power tower settlement monitoring system, a general broadband LED light source is usually selected, that is, a 60nm broadband wavelength light source of 1520nm-1580nm. This light source can adjust broadband light of different optical powers and transmit it into the input optical fiber of different couplers. However, if the measured mountain location or river basin location is too large in area affected by settlement, that is, the optical fiber is too long, a broadband light source with higher output power is required. An erbium-doped fiber amplifier EDFA can be used to amplify the optical power in the 1520nm-1580nm band, or an amplified spontaneous emission ASE high-power light source can be used directly to ensure that the intensity of the received fiber Bragg grating 8 reflected light is high enough.

[0045] The multi-branch coupler 4 is an important component of the sensor module 2 in the high-voltage power tower settlement monitoring system device, which is used to distribute optical signals from one input end to multiple output ends, or receive signals from multiple input ends and integrate them into one output end. In this embodiment, it plays a key role in distributing the optical signal emitted by the broadband LED light source to multiple fiber Bragg gratings 8 and receiving and integrating the reflected optical signals of multiple fiber Bragg gratings 8.

[0046] In the high-voltage power tower settlement monitoring system, a broadband LED light source 3 is connected to a plurality of multi-branch couplers 4, one of which is a 2x4 coupler. Figure 2 As shown, after receiving the broadband optical signal from the broadband LED light source 3, the multi-branch coupler 4 distributes the broadband light in proportion to the optical power; for the 2x4 coupler, it is formed by connecting three optical fiber couplers with different coupling rates. According to the different coupling rates of the three optical fiber couplers, different output ratios can be designed. In this embodiment, the power is proportionally distributed in two stages as above. The first-stage coupler distributes the power of the broadband light at 50:50, and the second-stage coupler distributes one of the 50% power optical fibers at 40:60, and the other at 20:80, thus forming an input optical fiber optical path with a power ratio of 1:2:3:4.

[0047] When broadband lights of different powers emitted by the 2x4 coupler enter different fiber Bragg gratings 8, light waves of specific wavelengths will be reflected back by the Bragg diffraction effect, while light waves of other wavelengths are transmitted through the optical fiber.

[0048] In the high-voltage power tower settlement monitoring system, the fiber Bragg grating 8 is usually used as a key component of the settlement sensor module. The cable optical fiber and the tower optical fiber are generally fixed on the high-voltage cable by first winding it on the high-voltage cable, and then the optical fiber is fixed at the measuring point, that is, the grating position, with an insulating material sleeve. The cable optical fiber is generally only wound on the high-voltage cable, while the tower optical fiber is at the power tower position. A section of the optical fiber will be fixed at the tower body position of interest to monitor the tower body deformation at that position, and each tower body optical fiber will leave a grating position near the bottom of the tower for temperature decoupling of the tower body deformation.

[0049] Wherein, every two fiber Bragg gratings 8 are fixed near the same high-voltage cable, the first fiber Bragg grating is only fixed on the high-voltage cable as the cable optical fiber, and the second fiber Bragg grating is partially fixed at the local deformation-prone part of the tower body and the bottom of the tower as the tower body optical fiber. The light intensity in the two fiber Bragg gratings 8 near the same high-voltage cable is the same, and the light intensity of the optical fibers near different high-voltage cables is different or proportional.

[0050] like Figure 4 As shown in the figure, the cable optical fiber and the tower optical fiber are both spirally wound on the high-voltage cable at non-measurement points and are intermittently fixed by insulating sleeves. The spiral winding of the cable optical fiber and the tower optical fiber can increase the friction resistance between the optical fiber and the high-voltage cable, better fix the optical fiber on the cable, reduce the fixing cost and difficulty, and prevent the optical fiber from falling off due to other natural factors.

[0051] For fiber grating distribution, the distribution interval in each optical fiber is periodic, and the relative position in each optical fiber is roughly the same. The interval is designed as:

[0052] like Figure 5 As shown, cable fiber Bragg grating distribution: It is mainly used to measure the settlement of each high-voltage power tower. In the cable optical fiber near the power tower, the gratings in the grating group are centered on the tower body, and multiple gratings are symmetrically and equidistantly distributed on both sides of the tower body. Generally, there are odd numbers of them. The central fiber Bragg grating is located at the junction of the high-voltage cable and the power tower. By setting up multiple gratings, it is ensured that the deformation difference of the grating part can be accurately measured, which is convenient for rapid early warning of the settlement of the power tower, and the measurement through deformation difference can effectively eliminate the influence of temperature.

[0053] The grating group distribution interval D1 of the cable optical fiber, that is, the distance from the central fiber grating of the previous cable grating group to the central fiber grating of the next cable grating group in the optical fiber, D1 is:

[0054] D1=l·θ

[0055] Where l is the length of the high-voltage cable between the two power towers, and θ is the angle of the helical winding of the optical fiber.

[0056] like Figure 5 As shown, the relative spacing of the gratings in the cable grating group depends on the measurement requirements, and it is sufficient to ensure that the temperature of the entire grating group is basically consistent.

[0057] like Figure 6 As shown, the fiber grating distribution on the tower body is mainly used to measure the local deformation of each power tower caused by settlement or other factors. The fiber grating of the tower body optical fiber is located in the part of the tower body that is prone to local deformation and the bottom of the tower that is not affected by local deformation. The distribution interval of the grating group also depends on the distance between the power towers, so as to accurately monitor the local strain of the tower body and give early warning of abnormal deformation of the tower body.

[0058] The grating group distribution interval of the tower body optical fiber is D2, that is, the distance from the last grating of the previous tower body grating group to the last grating of the next tower body grating group in the optical fiber, D2 is:

[0059] D2=l·θ+d

[0060] Where l is the length of the high-voltage cable between the two power towers, θ is the angle of the optical fiber spiral winding, and d is the length of the optical fiber wound around the power tower.

[0061] like Figure 6 As shown, the relative spacing of the gratings in the grating group depends on the position of the type of power tower that is prone to deformation, and needs to be customized according to the type of power tower. The actual grating spacing in the grating group requires specific analysis of specific circumstances.

[0062] The settlement state, settlement position and tower deformation of the power tower can be obtained in real time by the obtained wavelength change or wavelength difference change of the reflected light of the fiber Bragg grating 8. The reflected light of different wavelengths in the optical fiber will eventually be recoupled into the optical fiber of the multi-branch coupler 4.

[0063] The wavelength division multiplexer 5 is used in the optical fiber communication system to combine all the signals of different powers and wavelengths reflected from multiple optical fibers into the same optical fiber for transmission, or to separate the combined optical signal into their respective wavelengths. It can transmit multiple independent optical signals at the same time, thereby improving the transmission capacity and efficiency of the optical fiber communication system.

[0064] In the high-voltage power tower settlement monitoring system, after the optical signal coupled by the coupler enters the wavelength division multiplexer 5, it is decomposed into multiple optical signals of different wavelengths, which reduces the number of optical fibers, simplifies the wiring of the system, and improves the reliability and stability of signal transmission.

[0065] For cable optical fibers, when the reflection spectra of the same wavelength but different optical powers in two fiber Bragg gratings 8 overlap, the output light intensity is the sum of the output intensities of the two gratings. However, if the reflection spectra of the two gratings are not completely overlapped, but there is an unmeasurable interval, it means that an error has occurred in the measurement process. Since multiple optical fibers on multiple cables are used to measure the same tower body in this system, even if such an error occurs, the main peak height of the reflection spectrum of the same wavelength is still higher than the noise, which effectively prevents the problem of single optical fiber being affected by errors.

[0066] Moreover, for the optical fiber of the tower body, the fiber gratings distributed on the tower body also have power division processing for the optical fiber light signal, and can roughly determine the deformation position of the tower body through the changes in the wavelength of the optical signal with different light intensities.

[0067] According to whether the relative distance between the maximum peaks in the wavelength diagram obtained by the first fiber Bragg grating, i.e., the cable fiber grating in each group of fiber Bragg gratings changes too much, it is determined whether there is a power tower that has sunk; and according to the wavelength corresponding to the maximum peak in the wavelength diagram in which the relative distances between the peaks on the left and right sides change too much, and the corresponding relationship between the first fiber Bragg gratings of different light wavelengths and the measured position of the power tower, the specific position of the sunken power tower is determined.

[0068] According to the excessive movement of the peaks of different heights except the maximum peak in the wavelength diagram obtained by the second fiber Bragg grating, i.e. the fiber grating of the tower body in each group of fiber Bragg gratings, the specific position where the local deformation of the power tower occurs is determined; and then the position of the power tower where the local deformation of the tower body occurs is determined based on the corresponding relationship between the second fiber Bragg grating with different light wavelengths and the measured position of the power tower.

[0069] Assuming that there are five high-voltage cables on the power tower in the measured area, in this measurement system, each cable will be equipped with a cable optical fiber and a tower optical fiber, for a total of ten. The cable optical fiber is only spirally wound on the cable throughout the whole process. The five cable optical fibers have different optical powers. Therefore, in the final result graph, if there is no error and sedimentation, then on these five cable optical fibers, the grating position of the same reflection wavelength will have five overlapping output result peaks. If there is an error, only one or several peaks will fluctuate left and right, and the position of the total peak will not change. Only when sedimentation occurs will the position of the total peak move as a whole. Therefore, the impact of errors can be reduced. Under actual working conditions, changes in the temperature of the overall environment will also cause the overall movement of the total peak. Therefore, the final output result of this system for monitoring sedimentation is not the movement of the total peak, but the relative distance between the total peaks of each wavelength. Changes in the overall ambient temperature will only cause all the total peaks of the wavelength to move in the same direction, but the relative distance of the total peaks of each wavelength is still a constant. Only when sedimentation occurs will the relative distance between the total peaks change. When the relative distance difference between a certain total peak and the previous and next total peaks is too large, it means that the power tower at the grating position has settled and an early warning is needed.

[0070] like Figure 7 As shown in the figure, assuming that this is the monitoring result of a grating group near a power tower, it can be seen that if there is no settlement (solid line result), the relative distance between all total wave peaks is a constant value C. Only when settlement occurs (dashed line result), the total wave peaks will move, causing their relative distances to change, that is, the relative distance between the total wave peaks of a and b changes from C to A, and the relative distance between the total wave peaks of b and c changes from C to B. The error does not interfere much with the monitoring of settlement.

[0071] The tower body optical fiber will wrap the part with grating on the tower body, and the rest of the part is also wrapped on the cable. For the above example, assuming that each power tower has five easily deformed positions that need long-term deformation monitoring, then each of the five tower body optical fibers needs to have a grating to monitor these five positions, and each optical fiber needs to have a grating position attached to the bottom of the tower for temperature decoupling. In this example, for each power tower, the tower body optical fiber has ten gratings, two for each tower body optical fiber. Since the optical power of the five tower body optical fibers is different, the height of the output small wave peak results is different, which can be used to distinguish different deformation positions of the power tower. When the small wave peak at a certain height moves, the deformation position can be determined. As mentioned above, in the absence of error and deformation, the output result is that five small wave peaks overlap with each other. Even if there is an error that causes the small wave peak to move, in general, compared with the movement of the small wave peak caused by local deformation of the tower body, the movement of the small wave peak caused by the error will be smaller and less obvious. Therefore, the movement of small wave peaks at different heights indicates that local deformation has occurred in the tower body at different positions. Then, the specific location of the power tower where local deformation occurs is determined based on the wavelength corresponding to the total wave peak of the nearby small wave peak movement.

[0072] Because the optical powers of the five optical fibers are different, the tower position corresponding to the optical fiber can be selected according to the different optical powers, that is, the optical power of the optical fiber at each tower position to be measured is set at the beginning. Therefore, the optical power of the tower optical fiber corresponds to the tower position information, and the wavelength corresponds to the power tower position information. When the wavelength of the small wave peak of the fiber grating of a tower changes greatly after temperature decoupling, it means that the tower body at the grating position has been locally deformed and an early warning is required.

[0073] like Figure 8 As shown in the figure, the left side shows that the tower body is partially deformed, and the small wave peak moves obviously, while the right side shows that the grating is affected by the error, and the small wave peak does not move obviously. It can be seen that the results of the tower body fiber are also less affected by the error.

[0074] In summary, this system can, firstly, determine the location of the subsided power tower through the relative movement of the total wave peak, thereby providing a rapid early warning; secondly, it can determine the specific location of the tower body where local deformation has occurred through the movement of the small wave peak, thereby facilitating inspection and maintenance.

[0075] The avalanche diode 6 is based on the avalanche effect, which makes the avalanche diode have a high gain and amplification ability, and is used in high-speed photoelectric detection and amplification circuits in optical communication and optical sensing applications. The avalanche diode 6 receives the optical signal after the WDM processing of the wavelength division multiplexer 5, and converts it into a corresponding analog electrical signal. Moreover, since the avalanche diode has the characteristics of high gain and fast response, it can realize high-sensitivity detection of multiple weak optical signals after long-distance optical fiber transmission and proportional amplification of different optical fiber signal intensities, preventing the disappearance of signals in low-power optical fibers or optical signal crosstalk caused by different light intensities of different optical fibers. If the broadband light selects the amplified spontaneous emission ASE high-power light source, an ordinary photodetector can also be selected.

[0076] In this system, the analog data processed by the avalanche photodiode 6 will enter the data processing unit, which includes an A / D processor 7 and a data processing computer 9. The A / D processor 7 refers to an analog-to-digital converter, which is an electronic device or chip whose main function is to convert continuously changing analog signals into discrete digital signals. It uses sampling and quantization technology to discretize analog signals into digital values ​​through a series of operations.

[0077] Sampling: The A / D processor samples the analog signal at a certain frequency, that is, it samples the signal at continuous time intervals. Quantization: The sampled analog signal is quantized to map it into a series of discrete digital values.

[0078] The A / D processor is composed of a sampling circuit, a quantization circuit and a control circuit. In the high-voltage power tower settlement monitoring system, the sampling circuit is responsible for sampling the analog signal processed by the avalanche diode 6 to obtain signal samples regularly. The quantization circuit converts the sampled analog signal into a digital signal through a comparator and an encoder. The control circuit is used to control parameters such as sampling frequency, quantization accuracy and data output format. Through the data processing of the three circuits, the obtained digital signal can be provided to the data processing computer 9 for data analysis and processing.

[0079] The data processing computer 9 uses a common single-chip microcomputer, including a microcontroller core, a digital-to-analog converter, a clock and timer, a serial communication interface, a digital input / output (GPIO), a memory interface, an interrupt controller, and a power management unit. It can realize data acquisition, signal processing, communication, and system status management, thereby realizing accurate monitoring and timely response to the settlement of the power tower, and after calculation, it is connected to the power tower position distribution system for early warning of the settlement position. The data processing computer 9 needs to process the data of the tower body optical fiber, and decouple the deformation of other tower body positions by using the deformation at the grating at the bottom of the tower; it needs to process the data of the cable optical fiber, and decouple other factors such as temperature by calculating the deformation difference of adjacent gratings instead of calculating the deformation.

[0080] like Figure 3 As shown, the shell 10 is a rectangular structure or a cylindrical structure, which is suspended on the side of a high-voltage power tower near a power plant. A data processing computer 9 located at the power plant, i.e., where the high-voltage lines of the power tower are concentrated, uniformly processes the settlement and deformation data of the power towers in different directions and issues early warnings.

[0081] The power module 11 is composed of a conductor 13 and a current conditioner 12; Figure 4 As shown, the conductor 13 is wound on the high-voltage line, and the transmitted electric energy is used to generate alternating current in the conductor 13 through electromagnetic induction. The current conditioner 12 completes the rectification and filtering process to convert the unstable alternating current in the conductor into stable direct current, providing power for the entire system.

[0082] The FBG-based high-voltage power tower settlement monitoring system proposed in this embodiment adopts FBG sensors, which are not affected by the electromagnetic field of high-voltage cables, can maintain high data integrity and stability in high electromagnetic interference environments, are easy to install and low-cost, and are suitable for mass production and installation. The use of a wavelength division multiplexer to demodulate optical signals is cost-effective, and the measurement accuracy can be guaranteed. The use of multiple optical fibers with different optical powers at the same grating position for monitoring can effectively reduce the influence of noise signals on a single optical fiber signal and ensure the accuracy of the signal. In addition, the use of optical fiber transmission can well physically isolate the signal, which cannot be easily eavesdropped or intercepted, providing higher security and making it difficult for the transmission information to leak. The system can not only monitor the ground settlement of high-voltage power towers through changes in the wavelength of multi-grating superposition peaks, but also judge the abnormal tension of a single high-voltage cable through a single grating peak, which greatly facilitates the maintenance of high-voltage power towers and high-voltage cables.

[0083] Those skilled in the art should understand that the modules or steps of the present invention described above can be implemented by a general-purpose computer device, or alternatively, they can be implemented by a program code executable by a computing device, so that they can be stored in a storage device and executed by the computing device, or they can be made into individual integrated circuit modules, or multiple modules or steps therein can be made into a single integrated circuit module for implementation. The present invention is not limited to any specific combination of hardware and software.

[0084] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A high-voltage power tower settlement monitoring system based on FBG, characterized in that: include: Sensor modules and data processing units; The sensor module comprises: A broadband spectrum emitter for providing an excitation spectrum; A multi-branch coupler, used to split the excitation spectrum of the broadband spectrum emitter into a plurality of optical signals with different optical powers; Multiple groups of fiber Bragg gratings, each group of fiber Bragg gratings is connected to different high-voltage power cables respectively; the multiple groups of fiber Bragg gratings are used to receive multiple optical signals with different optical powers output by the multi-branch coupler respectively; each group of fiber Bragg gratings includes a first fiber Bragg grating and a second fiber Bragg grating, the first fiber Bragg grating is fixed on the high-voltage cable, and the second fiber Bragg grating is fixed on the local deformation-prone part of the tower body and the bottom of the tower; A wavelength division multiplexer, used for combining the optical signals reflected by the plurality of fiber Bragg gratings into a composite optical signal; an avalanche diode, used to receive the composite optical signal combined by the wavelength division multiplexer, and convert the composite optical signal into a corresponding analog electrical signal; The data processing unit is used for performing analog-to-digital conversion and analyzing and processing on the analog electrical signal converted by the avalanche diode to obtain the settlement detection result of the high-voltage power tower; in the data processing unit, whether settlement occurs is determined according to the change in the relative distance between the maximum peaks in the wavelength diagram obtained by the first fiber Bragg grating in each group of fiber Bragg gratings; the specific position of the settled power tower is determined according to the wavelength corresponding to the maximum peak in which the relative distances between the peaks on the left and right sides change too much in the wavelength diagram obtained by each group of fiber Bragg gratings, and the correspondence between the first fiber Bragg gratings of different optical wavelengths and the measured power tower position; the local deformation position of the tower body is determined according to the excessive movement of other peaks of different heights except the maximum peak in the wavelength diagram obtained by the second fiber Bragg grating, i.e., the fiber grating of the tower body in each group of fiber Bragg gratings; based on the correspondence between the second fiber Bragg gratings of different optical wavelengths and the measured power tower position, the position of the power tower where the local deformation of the tower body occurs is determined.

2. A high-voltage power tower settlement monitoring system based on FBG as claimed in claim 1, characterized in that: The fiber light intensity of the fiber Bragg gratings in each group of fiber Bragg gratings connected to the same high-voltage electric cable is the same, and the fiber light intensity of each group of fiber Bragg gratings connected to different high-voltage electric cables is different or proportional.

3. The FBG-based high-voltage power tower settlement monitoring system according to claim 1, characterized in that: The multi-branch coupler distributes the optical power in proportion to the excitation spectrum emitted by the broadband spectrum emitter.

4. The FBG-based high-voltage power tower settlement monitoring system according to claim 1, characterized in that: The measuring point positions of the first fiber Bragg grating and the second fiber Bragg grating are fixed at the measuring point through an insulating sleeve; the first fiber Bragg grating and the second fiber Bragg grating are spirally wound on the high-voltage cable at the non-measuring point.

5. The FBG-based high-voltage power tower settlement monitoring system according to claim 1, characterized in that: The distribution interval of the grating group of the first fiber Bragg grating is determined according to the length of the high-voltage cable between the power towers and the angle of the spiral winding of the optical fiber; the grating position interval in the grating group is symmetrically and equidistantly arranged with the high-voltage power tower as the center.

6. The FBG-based high-voltage power tower settlement monitoring system according to claim 1, characterized in that: The distribution interval of the grating group of the second fiber Bragg grating is determined according to the length of the high-voltage cable between the power towers, the angle of the spiral winding of the optical fiber and the length of the optical fiber of the tower body wound on the power tower.

7. The FBG-based high-voltage power tower settlement monitoring system according to claim 1, characterized in that: The data processing unit includes an A / D module, and the A / D module is used to perform analog-to-digital conversion on the analog electrical signal converted by the avalanche diode.

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