阅读说明：本技术 一种opgw光缆温度监测系统 (OPGW optical cable temperature monitoring system ) 是由 尹悦 陈硕 周文婷 颜哲昊 孙少华 郭经红 宋广磊 张治国 于 2020-12-29 设计创作，主要内容包括：本发明提供了一种OPGW光缆温度监测系统,包括：FBG监测设备(1)、分布式监测设备(2)以及数据处理中心(3)；所述FBG监测设备(1)和分布式监测设备(2)一端通过波分复用器(4)并列连接到待测光缆,另一端并列连接到所述数据处理中心(3)；所述FBG监测设备(1)包括FBG传感解调设备和串联的多个FBG光栅,所述串联的多个FBG光栅离散的分布于所述待测光缆的线杆上；其中,所述FBG传感解调设备(1)通过对所述FBG光栅反射光信号的解调,监测所述FBG光栅所在位置的所述待测光缆的温度变化,所述分布式监测设备(2)对所述待测光缆连续位置的温度变化进行监测。本发明能够准确监测光缆的温度变化。(The invention provides an OPGW optical cable temperature monitoring system, comprising: the system comprises FBG monitoring equipment (1), distributed monitoring equipment (2) and a data processing center (3); one ends of the FBG monitoring equipment (1) and the distributed monitoring equipment (2) are connected in parallel to an optical cable to be tested through a wavelength division multiplexer (4), and the other ends of the FBG monitoring equipment and the distributed monitoring equipment are connected in parallel to the data processing center (3); the FBG monitoring device (1) comprises an FBG sensing demodulation device and a plurality of FBG gratings connected in series, and the plurality of FBG gratings connected in series are discretely distributed on a wire rod of the optical cable to be detected; the FBG sensing demodulation equipment (1) monitors the temperature change of the optical cable to be detected at the FBG grating position through the demodulation of the FBG grating reflected light signal, and the distributed monitoring equipment (2) monitors the temperature change of the continuous position of the optical cable to be detected. The invention can accurately monitor the temperature change of the optical cable.)

1. An OPGW optical cable temperature monitoring system, comprising:

the system comprises FBG monitoring equipment (1), distributed monitoring equipment (2) and a data processing center (3); one ends of the FBG monitoring equipment (1) and the distributed monitoring equipment (2) are connected in parallel to an optical cable to be tested through a wavelength division multiplexer (4), and the other ends of the FBG monitoring equipment and the distributed monitoring equipment are connected in parallel to the data processing center (3); the FBG monitoring device (1) comprises an FBG sensing demodulation device and a plurality of FBG gratings connected in series, and the plurality of FBG gratings connected in series are discretely distributed on a wire rod of the optical cable to be detected; the FBG sensing demodulation equipment (1) monitors the temperature change of the optical cable to be detected at the FBG grating position through the demodulation of the FBG grating reflected light signal, and the distributed monitoring equipment (2) monitors the temperature change of the continuous position of the optical cable to be detected.

2. The optical cable condition monitoring system according to claim 1, wherein the FBG sensing and demodulating device comprises a tunable laser (11), an acousto-optic modulator (12), a first coupler (13), a first circulator (14), a first detector (15), a second detector (16), a signal processor (17) and a computer (18) which are connected in sequence; the optical signal output by the acousto-optic modulator (12) is divided into a first optical path of 99% and a second optical path of 1% after being output by the first coupler (13), the first optical path of 99% is connected with the first interface of the first circulator (14) and enters the optical cable to be tested through the second interface of the first circulator (14), the optical signal returned by the optical cable to be tested enters the second detector (16) through the third interface of the first circulator (14), the second optical path of 1% enters the first detector (15), and the first detector (15) and the second detector (16) are connected in parallel with the signal processor (17).

3. The cable condition monitoring system according to claim 2, wherein the computer (18) is connected to the tunable laser (11) and the acousto-optic modulator (12), respectively, for synchronously controlling the frequency of the tunable laser (11) and the acousto-optic modulator (12); the wavelength range of the tunable laser (11) is 1520-1600 nm, and the modulation frequency of the computer (18) is 200 Hz.

4. The optical cable status monitoring system according to claim 3, wherein the wavelength offset and the FBG fiber grating temperature in the FBG sensing and demodulating equipment satisfy the following relationship:

Δλ_B＝K_TΔT

wherein λ is_BIs the central reflection wavelength, Delta lambda, of the fiber grating_BDelta T is the change in temperature, K, in the change in the center wavelength at the time of the temperature change_TIs the coefficient of the center wavelength shift with respect to temperature.

5. The optical cable condition monitoring system according to claim 1, wherein the distributed monitoring device (2) comprises an optical signal detection unit (21), an optical-to-electrical conversion unit (22), a sweep frequency unit (23), and a computer (24), the optical signal detection unit (21) is connected with the sweep frequency unit (23) through the optical-to-electrical conversion unit (22), and the sweep frequency unit (23) is connected with the computer (24).

6. The optical cable state monitoring system according to claim 5, wherein the optical signal detection unit (21) includes a distributed feedback type semiconductor laser (2101), a first amplifier (2102), a second coupler (2103), a Mach-Zehnder modulator (2104), a second amplifier (2105), a first polarization scrambler (2106), a third coupler (2107), a third amplifier (2108), a second circulator (2109), a second polarization scrambler (2110), and a fourth coupler (2111) which are connected in sequence.

7. The optical cable condition monitoring system according to claim 7, wherein an optical signal output by the distributed feedback semiconductor laser (2101) is amplified by the first amplifier (2102), output by the second coupler (2103), and divided into a third optical path of 50% and a fourth optical path of 50%, the third optical path of 50% enters the optical cable under test through the mach-zehnder modulator (2104), the second amplifier (2105), the first polarization scrambler (2106), and the third coupler (2107), a backscattered light signal returned from the optical cable under test enters the third amplifier (2108), the second circulator (2109), and the fourth coupler (2111) through the third coupler (2107), and the fourth optical path of 50% is connected to the fourth coupler (2111) through the second polarization scrambler (2110).

8. Cable condition monitoring system according to claim 7, wherein the sweep unit (23) comprises: a mixer (231), a high-frequency oscillator (232), and a wideband low-pass filter (233), wherein the high-frequency oscillator (232) and the wideband low-pass filter (233) are both connected to the mixer (231).

9. Cable condition monitoring system according to claim 8, wherein the third coupler (2107) and the fourth coupler (2111) are each 50:50 coupler.

10. The optical cable condition monitoring system according to claim 9, wherein the brillouin frequency shift and the temperature to which the optical fiber is subjected in the distributed monitoring apparatus (2) satisfy the following relationship:

ν_B(t)＝ν_B(t₀)[1+C_t(t-t₀)]

wherein, v_B(t) is temperature-induced Brillouin frequency shift,. nu_B(t₀) Is a Brillouin frequency shift caused by initial state temperature, C_tIs the temperature coefficient, t₀And t is the initial temperature and the changed temperature, respectively.

Technical Field

The invention relates to the technical field of optical fibers, in particular to an OPGW optical cable temperature monitoring system.

Background

The monitoring of the icing state of the power transmission line is developed from the past manual line patrol to the popularization of an electronic monitoring system nowadays, and the monitoring technology of the icing state of the power transmission line, although having great development and progress, still faces a serious challenge. At present, the on-line monitoring system for the icing state of the power transmission line is mainly formed by building various electronic sensors, so that an additional power supply and a power supply pipeline are required to be installed and laid when the monitoring system is built, and although stable power supply can be ensured, the use environment of the monitoring system is undoubtedly limited. The traditional electronic sensors are active devices, and are extremely susceptible to interference in a complex electromagnetic environment such as a high-voltage transmission line, so that remote transmission of monitoring data and data accuracy are difficult to guarantee.

Therefore, the current electronic power transmission line icing monitoring system is difficult to meet the real-time monitoring requirement on the icing state of the field power transmission line with severe geographical conditions and climatic environments.

Disclosure of Invention

The present invention aims to provide an OPGW optical cable temperature monitoring system that can solve at least one of the above mentioned technical problems. The specific scheme is as follows:

according to an embodiment of the present invention, there is provided an OPGW optical cable temperature monitoring system, including:

the system comprises FBG monitoring equipment 1, distributed monitoring equipment 2 and a data processing center 3; one ends of the FBG monitoring equipment 1 and the distributed monitoring equipment 2 are connected in parallel to an optical cable to be tested through a wavelength division multiplexer 4, and the other ends of the FBG monitoring equipment and the distributed monitoring equipment are connected in parallel to the data processing center 3; the FBG monitoring device 1 comprises FBG sensing demodulation equipment and a plurality of FBG gratings connected in series, and the plurality of FBG gratings connected in series are discretely distributed on a wire rod of the optical cable to be detected; the FBG sensing demodulation equipment 1 monitors the temperature change of the optical cable to be detected at the FBG grating position through the demodulation of the FBG grating reflected light signal, and the distributed monitoring equipment 2 monitors the temperature change of the continuous position of the optical cable to be detected.

Optionally, the FBG sensing and demodulating device includes a tunable laser 11, an acousto-optic modulator 12, a first coupler 13, a first circulator 14, a first detector 15, a second detector 16, a signal processor 17, and a computer 18, which are connected in sequence; the optical signal output by the acousto-optic modulator 12 is divided into a first optical path of 99% and a second optical path of 1% after being output by the first coupler 13, the first optical path of 99% is connected with the first interface of the first circulator 14 and enters the optical cable to be tested through the second interface of the first circulator 14, the optical signal returned from the optical cable to be tested enters the second detector 16 through the third interface of the first circulator 14, the second optical path of 1% enters the first detector 15, and the first detector 15 and the second detector 16 are connected in parallel to the signal processor 17.

Optionally, the computer 18 is respectively connected to the tunable laser 11 and the acousto-optic modulator 12, and is configured to synchronously control the frequencies of the tunable laser 11 and the acousto-optic modulator 12; the wavelength range of the tunable laser 11 is 1520-1600 nm, and the modulation frequency of the computer 18 is 200 Hz.

Optionally, the wavelength offset and the temperature of the FBG fiber grating in the FBG sensing and demodulating device satisfy the following relationship:

Δλ_B＝K_TΔT

wherein λ is_BIs the central reflection wavelength, Delta lambda, of the fiber grating_BDelta T is the change in temperature, K, in the change in the center wavelength at the time of the temperature change_TIs the coefficient of the center wavelength shift with respect to temperature.

Optionally, the distributed monitoring apparatus 2 includes an optical signal detection unit 21, a photoelectric conversion unit 22, a sweep frequency unit 23, and a computer 24, where the optical signal detection unit 21 is connected to the sweep frequency unit 23 through the photoelectric conversion unit 22, and the sweep frequency unit 23 is connected to the computer 24.

Optionally, the optical signal detection unit 21 includes a distributed feedback semiconductor laser 2101, a first amplifier 2102, a second coupler 2103, a mach-zehnder modulator 2104, a second amplifier 2105, a first polarization scrambler 2106, a third coupler 2107, a third amplifier 2108, a second circulator 2109, a second polarization scrambler 2110, and a fourth coupler 2111, which are sequentially connected.

Optionally, after being amplified by the first amplifier 2102, the optical signal output by the distributed feedback semiconductor laser 2101 is output by the second coupler 2103, and then is divided into a 50% third optical path and a 50% fourth optical path, where the 50% third optical path enters the optical cable to be tested through the mach-zehnder modulator 2104, the second amplifier 2105, the first polarization scrambler 2106, and the third coupler 2107, a backscattered light signal returned from the optical cable to be tested enters the third amplifier 2108, the second circulator 2109, and the fourth coupler 2111 through the third coupler 2107, and the 50% fourth optical path is connected to the fourth coupler 2111 through the second polarization scrambler 2110.

Optionally, the frequency sweeping unit 23 includes: a mixer 231, a high-frequency oscillator 232, and a wide-band low-pass filter 233, wherein the mixer 231 is connected to the high-frequency oscillator 232 and the wide-band low-pass filter 233.

Optionally, the third coupler 2107 and the fourth coupler 2111 are both 50:50 couplers.

Optionally, the brillouin frequency shift and the temperature applied to the optical fiber in the distributed monitoring device 2 satisfy the following relationship:

ν_B(t)＝ν_B(t₀)[1+C_t(t-t₀)]

wherein, v_B(t) is temperature-induced Brillouin frequency shift,. nu_B(t₀) Is a Brillouin frequency shift caused by initial state temperature, C_tIs the temperature coefficient, t₀And t is the initial temperature and the changed temperature, respectively.

Compared with the prior art, the scheme of the embodiment of the invention at least has the following beneficial effects:

the OPGW optical cable temperature monitoring system provided by the invention combines the advantages that the FBG optical fiber grating can be used for multi-point accurate measurement and the BOTDR can be used for continuous measurement as the distributed optical fiber, so that the OPGW optical cable temperature monitoring system can be used for dynamically monitoring the temperature change of the optical cable to be detected, the temperature change state of the specific position of the optical fiber can be obtained, the continuous position of the optical fiber can be monitored, the non-blind area coverage monitoring along the whole optical fiber can be realized, the defect that the temperature monitoring cannot be carried out between the discrete points of the FBG optical fiber grating is overcome, and the practicability of the optical cable monitoring system is improved.

Therefore, the FBG sensing technology based on the fiber bragg grating and the BOTDR technology based on the distributed fiber sensing are combined, the integrated sensing mechanism of the distributed Brillouin scattering and the fiber bragg grating is fused, so that the high efficiency of fiber temperature monitoring can be realized, the abnormal temperature information is accurately positioned, and the temperature state of the optical cable can be comprehensively and comprehensively monitored.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort. In the drawings:

FIG. 1 illustrates an overall schematic view of a fiber optic cable condition monitoring system according to an embodiment of the present invention;

FIG. 2 shows an overall structural schematic diagram of an FBG monitoring device according to an embodiment of the invention;

FIG. 3 shows a detailed structural schematic diagram of an FBG monitoring device according to an embodiment of the invention;

fig. 4 shows a schematic structural diagram of a distributed monitoring system according to an embodiment of the invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the present invention will be described in further detail with reference to the accompanying drawings, and it is apparent that the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The terminology used in the embodiments of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the examples of the present invention and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise, and "a plurality" typically includes at least two.

It should be understood that the term "and/or" as used herein is merely one type of association that describes an associated object, meaning that three relationships may exist, e.g., a and/or B may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

It should be understood that although the terms first, second, third, etc. may be used to describe embodiments of the present invention, they should not be limited to these terms.

It is also noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that an article or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such article or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in the article or device in which the element is included.

Alternative embodiments of the present invention are described in detail below with reference to the accompanying drawings.

The optical cable state monitoring system respectively monitors the OPGW optical cables in each monitoring line, a plurality of power transmission lines and optical fibers are distributed in the optical cables, and optical fiber signals are monitored by an optical means, so that the state change of the OPGW optical cables caused by temperature and stress can be obtained.

The data processing PC of each optical cable state monitoring system collects the processed corresponding monitoring results into a data center through an Ethernet port in a TCP/IP mode and by using a power communication channel through a gateway, and the data center can perform centralized management and result display on the optical cable state monitoring systems distributed in various places.

As shown in fig. 1, the Optical cable monitoring system is composed of an FBG (Fiber Bragg Grating) monitoring device 1 and a BOTDR (Brillouin Optical Time Domain Reflectometer) distributed monitoring device 2, and is configured to collect and monitor multi-parameter data in an Optical cable line. The optical cable state monitoring device and system based on the power optical fiber network not only have the outstanding advantages of being passive, anti-interference and maintenance-free, but also solve the hidden danger that the traditional monitoring wireless communication is unstable and the information is unsafe.

The FBG monitoring device 1 includes a passive fiber grating monitoring device, an optical fiber cable with special power such as OPGW, an information demodulation and monitoring platform, and the like. The fiber grating type sensing monitoring device is installed on a transmission line tower of a monitoring point, active equipment such as an information demodulation and monitoring platform is installed in a substation machine room, and the two are connected through special power optical cables such as an OPGW (optical fiber composite overhead ground wire). The FBG monitoring equipment 1 overcomes the outstanding problems of low reliability, low precision, difficult integration, difficult maintenance and the like of the traditional monitoring device, realizes the non-regeneration and maintenance-free of the field monitoring device, and realizes the safety and stability of information communication through optical fiber wired communication. The distributed monitoring equipment 2 comprises an OPGW optical cable, a BOTDR monitoring host, a photoelectric detector, a microwave frequency sweeping module, a data processing PC and the like. The distributed monitoring equipment 2 uses the redundant optical fiber of the optical fiber cable of the OPGW as a sensor to acquire information such as optical parameters of the optical fiber in the OPGW.

OPGW optical cable temperature monitoring system includes: the system comprises FBG monitoring equipment 1, distributed monitoring equipment 2 and a data processing center 3; one ends of the FBG monitoring equipment 1 and the distributed monitoring equipment 2 are connected in parallel to an optical cable to be tested through a wavelength division multiplexer 4, and the other ends of the FBG monitoring equipment and the distributed monitoring equipment are connected in parallel to the data processing center 3.

As shown in fig. 2, the FBG monitoring device 1 includes an FBG sensing and demodulating device a and a plurality of serially connected FBG gratings B, and the plurality of serially connected FBG gratings are discretely distributed on a pole of the optical cable to be tested; the FBG sensing demodulation equipment monitors the temperature change of the optical cable to be detected at the FBG grating position through demodulating the FBG grating reflected light signal, and the distributed monitoring equipment 2 monitors the temperature change of the continuous position of the optical cable to be detected.

As an embodiment, as shown in fig. 3, the FBG sensing and demodulating device includes a tunable laser 11, an acousto-optic modulator 12, a first coupler 13, a first circulator 14, a first detector 15, a second detector 16, a signal processor 17 and a computer 18, which are connected in sequence; the optical signal output by the acousto-optic modulator 12 is divided into a first optical path of 99% and a second optical path of 1% after being output by the first coupler 13, the first optical path of 99% is connected with the first interface of the first circulator 14 and enters the optical cable to be tested through the second interface of the first circulator 14, the optical signal returned from the optical cable to be tested enters the second detector 16 through the third interface of the first circulator 14, the second optical path of 1% enters the first detector 15, and the first detector 15 and the second detector 16 are connected in parallel to the signal processor 17.

Optionally, the computer 18 is respectively connected to the tunable laser 11 and the acousto-optic modulator 12, and is configured to synchronously control the frequencies of the tunable laser 11 and the acousto-optic modulator 12; the wavelength range of the tunable laser 11 is 1520-1600 nm, and the modulation frequency of the computer 18 is 200 Hz.

Optionally, the wavelength offset and the temperature of the FBG fiber grating in the FBG sensing and demodulating device satisfy the following relationship:

Δλ_B＝K_TΔT

wherein λ is_BIs the central reflection wavelength, Delta lambda, of the fiber grating_BDelta T is the change in temperature, K, in the change in the center wavelength at the time of the temperature change_TIs the coefficient of the center wavelength shift with respect to temperature.

The temperature sensing device based on the FBG is designed with a stress isolation device on the basis of applying an FBG detection module, so that the wavelength offset of the FBG is only influenced by temperature change and is not influenced by stress change. The insulation is designed with sufficient ventilation to prevent the FBG placed in the insulation from measuring temperatures other than the ambient temperature but inside the insulation.

As an embodiment, as shown in fig. 4, the distributed monitoring apparatus 2 includes an optical signal detection unit 21, a photoelectric conversion unit 22, a sweep frequency unit 23, and a computer 24, where the optical signal detection unit 21 is connected to the sweep frequency unit 23 through the photoelectric conversion unit 22, and the sweep frequency unit 23 is connected to the computer 24.

Optionally, the optical signal detection unit 21 includes a distributed feedback semiconductor laser 2101, a first amplifier 2102, a second coupler 2103, a mach-zehnder modulator 2104, a second amplifier 2105, a first polarization scrambler 2106, a third coupler 2107, a third amplifier 2108, a second circulator 2109, a second polarization scrambler 2110, and a fourth coupler 2111, which are sequentially connected.

Optionally, after being amplified by the first amplifier 2102, the optical signal output by the distributed feedback semiconductor laser 2101 is output by the second coupler 2103, and then is divided into a 50% third optical path and a 50% fourth optical path, where the 50% third optical path enters the optical cable to be tested through the mach-zehnder modulator 2104, the second amplifier 2105, the first polarization scrambler 2106, and the third coupler 2107, a backscattered light signal returned from the optical cable to be tested enters the third amplifier 2108, the second circulator 2109, and the fourth coupler 2111 through the third coupler 2107, and the 50% fourth optical path is connected to the fourth coupler 2111 through the second polarization scrambler 2110.

Optionally, the frequency sweeping unit 23 includes: a mixer 231, a high-frequency oscillator 232, and a wide-band low-pass filter 233, wherein the mixer 231 is connected to the high-frequency oscillator 232 and the wide-band low-pass filter 233.

Optionally, the third coupler 2107 and the fourth coupler 2111 are both 50:50 couplers.

The brillouin frequency shift is related to the fiber material and can be expressed as:

ν_B＝2nV_a/λ

wherein n is core refractive index, V_aλ is the wavelength of the incident light, which is the phonon-moving speed of the fiber medium. When the optical fiber materials are the same, the Brillouin frequency shift and the temperature and the strain of the optical fiber are in a linear relation, and the Brillouin frequency shift and the temperature of the optical fiber satisfy the following relation:

ν_B(ε)＝ν_B(ε₀)[1+C_εε]

ν_B(t)＝ν_B(t₀)[1+C_t(t-t₀)]

wherein, v_B(epsilon) is strain-induced Brillouin frequency shift, v_B(ε₀) Is Brillouin frequency shift caused by initial state strain, C_εTo be in due courseCoefficient of variation, ε being strain, v_B(t) is temperature-induced Brillouin frequency shift,. nu_B(t₀) Is a Brillouin frequency shift caused by initial state temperature, C_tIs the temperature coefficient, t₀And t is the initial temperature and the changed temperature, respectively.

A distributed feedback type semiconductor laser with a narrow line width (the line width is less than 1MHz) is selected as a light source of the system to continuously emit continuous and constant-amplitude optical signals to the system, the power of the optical signals is amplified to be more than 10mW through an EDFA (erbium-doped fiber amplifier) of a first stage, and then the optical signals are divided into two paths of detection light and local coherent light through a coupler of 50/50. The detection light is modulated into pulse light by a high-performance Mach-Zehnder modulator, the power of the pulse light is amplified to 160mW by the second-stage EDFA, and the pulse light is injected into the line optical cable to be detected. Optical pulses generate spontaneous Brillouin scattering after entering a line optical cable to be detected, the difference between a scattered light signal and an input light signal is about 11GHz, and the power of the backward Brillouin scattering signal is very weak, so that when the Brillouin scattering signal enters a receiving loop through the reflection of a coupler, a third-stage EDFA amplification needs to be added, and the optical signals are input into an FBG after being subjected to three-stage amplification to inhibit spontaneous radiation noise generated in the EDFA amplification process. At a receiving end, the Brillouin scattering signal is coherent with a high-frequency heterodyne receiver of local coherent light, photoelectric conversion is realized at the same time, the received high-frequency Brillouin scattering spectrum signal is subjected to frequency mixing with a local oscillator, the center frequency is reduced to an intermediate frequency, and the Brillouin scattering spectrum signal can be obtained through a low-pass filter.

The OPGW optical cable temperature monitoring system provided by the invention combines the advantages that the FBG optical fiber grating can be used for multi-point accurate measurement and the BOTDR can be used for continuous measurement as the distributed optical fiber, so that the OPGW optical cable temperature monitoring system can be used for dynamically monitoring the temperature change of the optical cable to be detected, the temperature change state of the specific position of the optical fiber can be obtained, the continuous position of the optical fiber can be monitored, the non-blind area coverage monitoring along the whole optical fiber can be realized, the defect that the temperature monitoring cannot be carried out between the discrete points of the FBG optical fiber grating is overcome, and the practicability of the optical cable monitoring system is improved.

Therefore, the FBG sensing technology based on the fiber bragg grating and the BOTDR technology based on the distributed fiber sensing are combined, the integrated sensing mechanism of the distributed Brillouin scattering and the fiber bragg grating is fused, so that the high efficiency of fiber temperature monitoring can be realized, the abnormal temperature information is accurately positioned, and the temperature state of the optical cable can be comprehensively and comprehensively monitored.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.