A stress and temperature monitoring system for OPPC optical cables based on distributed optical fibers

Abstract

This utility model relates to the field of fiber optic sensing technology, specifically to a stress and temperature monitoring system for OPPC optical cables based on distributed optical fibers. The system includes a narrow-line laser, a polarization controller, an erbium-doped fiber amplifier, a filter, an OPPC optical cable, a narrow-line laser, a coupler, a polarization controller, an encoder, an electro-optic modulator, an electro-optic modulator, an electro-optic modulator, a polarization scrambler, a coupler, an erbium-doped fiber amplifier, a circulator, a wavelength division multiplexing (WDM) device, a filter, a photodetector, a data acquisition card, a decoder, an avalanche photodiode, another data acquisition card, another decoder, and a computer. The monitoring system provided by this utility model can achieve decoupled monitoring of fiber stress and temperature; it utilizes a WDM device to save on fiber core space occupied during monitoring; and it uses an encoder to increase the temperature monitoring length of the optical cable from 20km to 75km.

Description

Technical Field

[0001] This utility model relates to the field of fiber optic sensing technology, specifically to an OPPC optical cable stress and temperature monitoring system based on distributed optical fibers. Background Technology

[0002] OPPC (Optical Phase Conductor) is a relatively mature optical cable technology. It replaces one or more steel wires in traditional power transmission conductors with stainless steel tube optical units, which are then twisted together with (aluminum-clad) steel wires or aluminum (alloy) wires to form OPPC. Compared to OPGW optical cables, OPPC optical cables have advantages such as convenient de-icing and high reliability in heavily icing areas.

[0003] Currently, commonly used online monitoring methods for power transmission lines mainly include manual observation, image and video monitoring, and tension sensing. In recent years, driven by the demands of various industries for long-distance monitoring, high precision, and ease of monitoring, distributed sensing technology has developed rapidly and is gradually being applied in power system transmission lines. Distributed sensing technology uses optical fiber as both a transmission channel and a sensor, giving it inherent advantages over other monitoring methods. First, by utilizing redundant fiber cores in OPPC optical cables, and monitoring the stress and temperature of the fiber cores, distributed sensing technology can accurately determine the stress and temperature of the phase conductors, thereby revealing the icing status of the phase conductors. Second, the distributed monitoring host is installed in the substation's equipment room, whose operating environment ensures reliable power supply, convenient maintenance, and stable information transmission for the monitoring host.

[0004] The following technical problems exist in the existing schemes for monitoring fiber stress and temperature: (1) At present, the monitoring of fiber stress and temperature usually adopts the BOTDA / BOTDR system. However, the BOTDA / BOTDR system is sensitive to changes in temperature and stress. There is little research on how to decouple the monitoring of temperature and stress; (2) To monitor fiber stress and temperature, four fiber cores are generally required for monitoring the temperature and stress of the optical cable (two cores are used for measuring temperature and two cores are used for measuring stress), which wastes the already scarce optical cable fiber core resources in the power system; (3) The Raman scattering signal-to-noise ratio is low, which limits its measurement accuracy and measurement distance (generally within 20km). This measurement distance is far from sufficient for high-voltage transmission lines.

[0005] In summary, this utility model provides a stress and temperature monitoring system for OPPC optical cables based on distributed optical fibers to solve the problems existing in the prior art. Utility Model Content

[0006] The purpose of this utility model is to provide a stress and temperature monitoring system for OPPC optical cables based on distributed optical fibers. The specific technical solution is as follows: An OPPC optical cable stress and temperature monitoring system based on distributed optical fiber includes a narrow-line laser, a polarization controller, an erbium-doped fiber amplifier, a filter, an OPPC optical cable, a narrow-line laser, a coupler, a polarization controller, an encoder, an electro-optic modulator, an electro-optic modulator, an electro-optic modulator, a polarization scrambler, a coupler, an erbium-doped fiber amplifier, a circulator, a wavelength division multiplexing (WDM) device, a filter, a photodetector, a data acquisition card, a decoder, an avalanche photodiode, a data acquisition card, a decoder, and a computer. The narrow-line laser, polarization controller, electro-optic modulator, erbium-doped fiber amplifier, and filter are connected in series, and the output of the filter is connected to the OPPC optical cable. The narrow-line laser 2 is connected to the coupler 1. The first output terminal of the coupler 1 is connected to the polarization controller 2. The polarization controller 2, the electro-optic modulator 2, and the polarization scrambler are connected in series. The output terminal of the polarization scrambler is connected to the first input terminal of the coupler 2. The second output terminal of the coupler one is connected to the electro-optic modulator three, and the electro-optic modulator three is connected to the second input terminal of the coupler two; The output of coupler 2 is connected to erbium-doped fiber amplifier 2, which is connected to OPPC optical cable via circulator and wavelength division multiplexing (WDM) device; the first output of WDM device is connected to circulator, and circulator, filter 2, photodetector, data acquisition card 1 and decoder 1 are connected in series; the output of decoder 1 is connected to computer. The second output terminal of the wavelength division multiplexing (WDM) device is connected to the avalanche photodiode. The avalanche photodiode, the second data acquisition card, and the second decoder are connected in series. The output terminal of the second decoder is connected to the computer. The encoder is connected to electro-optic modulator two and electro-optic modulator three, respectively.

[0007] Furthermore, the circulator includes three ports: the first port is connected to the output of the second erbium-doped fiber amplifier, the second port is connected to the first output and / or the first input of the wavelength division multiplexing (WDM) device, and the third port is connected to the input of the second filter.

[0008] Furthermore, the narrow-line laser is used to output a first beam of light, which serves as the optical signal of the Brillouin scattering probe light. The first beam of light passes through a polarization controller, an electro-optic modulator, an erbium-doped fiber amplifier, and a filter in sequence before entering the optical cable under test. The narrow-line laser II is used to output a second beam. The second beam is split into a third beam and a fourth beam by a coupler I. The third beam serves as the optical signal of the Brillouin scattering pump beam. It passes through a polarization controller II, an electro-optic modulator II, a polarization scrambler, a coupler II, and an erbium-doped fiber amplifier II in sequence, and then enters the optical cable under test through a circulator and a wavelength division multiplexing device. The probe light interacts with the pump light to detect fiber stress and temperature. The fourth light path, as a Raman scattered light signal, passes sequentially through electro-optic modulator three, coupler two, erbium-doped fiber amplifier two, and then through circulator and wavelength division multiplexing equipment into the optical cable under test, for detecting fiber temperature.

[0009] Furthermore, the splitting ratio of the first coupler is 50:50.

[0010] Furthermore, the encoder is an S-pulse encoder.

[0011] Furthermore, the wavelength division equipment employs a wavelength division multiplexer.

[0012] Furthermore, the OPPC optical cable contains at least two fiber cores.

[0013] Furthermore, it also includes a microwave signal generator, which is connected to an electro-optic modulator.

[0014] The application of the technical solution of this utility model has the following beneficial effects: (1) This utility model provides a stress and temperature monitoring system for OPPC optical cables based on distributed optical fibers, including a narrow-line laser, a polarization controller, an erbium-doped fiber amplifier, a filter, an OPPC optical cable, a narrow-line laser, a coupler, a polarization controller, an encoder, an electro-optic modulator, an electro-optic modulator, an electro-optic modulator, a polarization scrambler, a coupler, an erbium-doped fiber amplifier, a circulator, a wavelength division multiplexing (WDM) device, a filter, a photodetector, a data acquisition card, a decoder, an avalanche photodiode, a data acquisition card, a decoder, and a computer; the narrow-line laser, polarization controller, electro-optic modulator, erbium-doped fiber amplifier, and filter are connected in series, and the output of filter is connected to the OPPC optical cable; the narrow-line laser is connected to coupler, and the first output of coupler is connected to polarization controller. The first coupler consists of a second electro-optic modulator, a second electro-optic modulator, and a polarizer connected in series. The output of the polarizer is connected to the first input of the second coupler. The second output of the first coupler is connected to a third electro-optic modulator, which is connected to the second input of the second coupler. The output of the second coupler is connected to an erbium-doped fiber amplifier, which is connected to an OPPC optical cable via a circulator and a wavelength division multiplexing (WDM) device. The first output of the WDM device is connected to the circulator. The circulator, a second filter, a photodetector, a first data acquisition card, and a first decoder are connected in series. The output of the first decoder is connected to a computer. The second output of the WDM device is connected to an avalanche photodiode. The avalanche photodiode, the second data acquisition card, and the second decoder are connected in series. The output of the second decoder is connected to a computer. The encoder is connected to both the second and third electro-optic modulators. In this invention, a narrow-line laser outputs a first beam, which serves as the optical signal for Brillouin scattering detection. This first beam passes sequentially through a polarization controller, an electro-optic modulator, an erbium-doped fiber amplifier, and a filter before entering the optical cable under test. A second narrow-line laser outputs a second beam, which is split into a third and a fourth beam by a coupler. The third beam serves as the optical signal for Brillouin scattering pump light, passing sequentially through a polarization controller, an electro-optic modulator, a polarization scrambler, a coupler, and an erbium-doped fiber amplifier before entering the optical cable under test via a circulator and wavelength division multiplexing (WDM) device. The detection beam interacts with the pump light to detect fiber stress and temperature. The fourth beam serves as the optical signal for Raman scattering, modulated into a pulse sequence by an electro-optic modulator, coupled with the pump light by a coupler, amplified by the erbium-doped fiber amplifier, and then entering the optical cable under test via a circulator and WDM device to detect fiber temperature. Finally, a computer decouples the fiber stress, providing data on fiber temperature and stress, thus enabling decoupled monitoring of fiber stress and temperature.

[0015] (2) In this utility model, a wavelength division multiplexer is used to multiplex the optical fiber signal into one fiber core to solve the problem of wasting optical fiber core resources caused by simultaneous monitoring of temperature and stress. Under normal circumstances, four fiber cores are required to monitor temperature and stress. With the wavelength division multiplexer, only two fiber cores are needed to monitor temperature and stress, saving the fiber cores occupied by monitoring.

[0016] (3) In this utility model, an S-pulse encoder is used to compensate for the inherent weakness of the Raman scattering signal, improve the signal-to-noise ratio, and increase the temperature monitoring length of the optical cable from 20km to 75km to meet the measurement requirements of high-voltage transmission lines.

[0017] In addition to the objectives, features, and advantages described above, this utility model has other objectives, features, and advantages. The present utility model will now be described in further detail with reference to the figures. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings: Figure 1 This is a spectrum of light scattered by an optical fiber; Figure 2 This is a BOTDA schematic diagram; Figure 3 This is a structural diagram of a typical BOTDA system monitoring device; Figure 4 This is a structural diagram of a typical ROTDR system monitoring device; Figure 5 This is a structural diagram of the monitoring system of this utility model; Among them, 1. Narrow-line laser I, 2. Polarization controller I, 3. Erbium-doped fiber amplifier I, 4. Filter I, 5. OPPC optical cable, 6. Narrow-line laser II, 7. Coupler I, 8. Polarization controller II, 9. Encoder, 10. Electro-optic modulator I, 11. Electro-optic modulator II, 12. Electro-optic modulator III, 13. Polarization scrambler, 14. Coupler II, 15. Erbium-doped fiber amplifier II, 16. Circulator, 17. Wavelength division multiplexing equipment, 18. Filter II, 19. Photodetector, 20. Data acquisition card I, 21. Decoder I, 22. Avalanche photodiode, 23. Data acquisition card II, 24. Decoder II, 25. Computer, 26. Microwave signal generator; Laser – Laser generator; Pulse – Pulse signal; PC – Polarization controller; RF – Microwave signal generator; EOM – Electro-optic modulator; PS – Polarization scrambler; EDFA – Erbium-doped fiber amplifier; FBG – Filter; Circulatro – Circulator; WDM – Wavelength division multiplexing device; PD – Photodetector; DAQ – Data acquisition card; APD – Avalanche photodiode; Optical Fiber – Optical fiber; Probe – Probe light; Pump – Pump light; Stokes – Stokes light; Anti-Stokes – Anti-Stokes light. Detailed Implementation

[0019] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered.

[0020] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0021] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0022] Example See Figure 1 Scattering can generally be classified into three types: Rayleigh scattering, Raman scattering, and Brillouin scattering. Figure 1 It can be seen that Rayleigh scattering has the highest intensity in the scattered signal, followed by Brillouin scattering, while Raman scattering has the lowest intensity. The OPPC optical cable stress and temperature monitoring system in this invention is a monitoring scheme based on the principles of Brillouin scattering and Raman scattering.

[0023] Reference Figure 2The measurement principle of a Brillouin scattering (BOTDA) system is as follows: BOTDA requires two narrow-linewidth laser sources, namely a pump light (pulse light signal) and a probe light (continuous light signal). When the two sources propagate in an optical fiber, the temperature, density, and strain of the fiber are different, causing scattering of the incident light. BOTDA utilizes the laser backscattering effect. The pump light and probe light are injected from opposite ends of the fiber. When the frequency difference between these two lights equals the Brillouin frequency shift in a certain region of the fiber, stimulated Brillouin amplification occurs in that region, resulting in energy transfer between the two beams. When the ambient temperature changes or the fiber deforms, the refractive index of the light changes accordingly, thus altering the Brillouin frequency shift of the fiber.

[0024] Reference Figure 3 , Figure 3 This diagram illustrates a typical BOTDA setup. A laser emits a beam of light, which is split into two streams by a coupler. One stream is modulated into a pulsed light signal by an electro-optic modulator (EOM) driven by a pulse signal and sent to a polarization scrambler (PS). The PS reduces the impact of polarization effects present in ordinary single-mode fiber on the performance of the Brillouin optical time-domain analysis sensor, improving the gain of the monitoring signal. The signal is then amplified by an erbium-doped amplifier (EDFA) and used as pump light in the fiber under test via a circulator. The other stream is modulated into a probe light by an electro-optic modulator driven by a microwave signal (RF), and then passes through an optical attenuator (VOA) to the fiber under test. The pump and probe lights interact within the fiber, and the resulting signal is filtered by a grating filter (FBG) and converted into an electrical signal by a photodetector (PD) for monitoring.

[0025] Based on existing research, the change in Brillouin frequency shift is linearly related to the temperature change and the axial stress change along the longitudinal axis of the optical fiber, as shown in the following equation: QUOTE (1); in: This represents the change in Brillouin frequency shift in the optical fiber. This represents the temperature variation coefficient of the Brillouin frequency shift. This represents the temperature change of the optical fiber. This represents the Brillouin frequency shift stress variation coefficient. Axial strain along the longitudinal axis of the optical fiber. For common single-mode optical cables used in power systems, the Brillouin frequency shift temperature variation coefficient is... The Brillouin frequency shift stress variation coefficient is approximately 1.1 MHz / ℃. Approximately 0.0483MHz / .

[0026] Reference Figure 4 , Figure 4 This is a structural diagram of a typical ROTDR system monitoring device. The scattered light from the fiber mainly consists of Stokes light and anti-Stokes light. The anti-Stokes light of Raman scattering is more sensitive to temperature, while the Stokes light is independent of temperature. Therefore, this principle can be used to measure the temperature in the fiber separately.

[0027] Stokes's formula for light intensity: (2); Anti-Stokes light intensity formula: (3); In the formula: Temperature at the location of fiber optic disturbance; This refers to the transmission loss of the incident light through the optical fiber. For anti-Stokes fiber transmission loss; This refers to the transmission loss of Stokes fiber optic cables. The scattering coefficient of Stokes fiber; The anti-Stokes fiber scattering coefficient; The intensity of the incident light; The backscattering coefficient of the optical fiber; The starting temperature location; For frequency shift wavenumber; The frequency of Stokes scattering; The frequency of anti-Stokes scattering; It is Planck's constant; is Boltzmann's constant.

[0028] Anti-Stokes light is significantly affected by external non-temperature factors (such as fiber optic cable stress and optical device instability), which can easily lead to errors. Therefore, Stokes light is generally used as the reference light intensity. The ratio of the two accurately reflects the temperature information at the measurement point, i.e.: (4); When the system is at the reference temperature hour, (5); Dividing equation (4) by equation (5), we get (6); The temperature in a local region of the distributed optical fiber can be obtained from equation (6). .

[0029] See Figure 5 , Figure 5This utility model provides a stress and temperature monitoring system for OPPC optical cables based on distributed optical fibers, comprising a narrow-line laser 1, a polarization controller 2, an erbium-doped fiber amplifier 3, a filter 4, an OPPC optical cable 5, a narrow-line laser 6, a coupler 7, a polarization controller 8, an encoder 9, an electro-optic modulator 10, an electro-optic modulator 11, an electro-optic modulator 3 12, a polarization scrambler 13, a coupler 14, an erbium-doped fiber amplifier 15, a circulator 16, a wavelength division multiplexing (WDM) device 17, a filter 18, a photodetector 19, a data acquisition card 20, a decoder 21, an avalanche photodiode 22, a data acquisition card 23, a decoder 24, and a computer 25; the narrow-line laser 1, the polarization controller 2, the electro-optic modulator 10, the erbium-doped fiber amplifier 3, and the filter 4 are connected in series, and the output end of the filter 4 is connected to the OPPC optical cable 5; The narrow-line laser 6 is connected to coupler 7. The first output terminal of coupler 7 is connected to polarization controller 8. Polarization controller 8, electro-optic modulator 11, and polarization scrambler 13 are connected in series. The output terminal of polarization scrambler 13 is connected to the first input terminal of coupler 14. The second output terminal of the coupler 7 is connected to the electro-optic modulator 12, and the output terminal of the electro-optic modulator 12 is connected to the second input terminal of the coupler 14. The output of coupler 14 is connected to erbium-doped fiber amplifier 15, the output of erbium-doped fiber amplifier 15 is connected to the first port of circulator 16, the second port of circulator 16 is connected to the first output and / or first input of wavelength division multiplexing (WDM) device 17, and WDM device 17 is connected to OPPC optical cable 5; circulator 16, filter 18, photodetector 19, data acquisition card 20, and decoder 21 are connected in series; the output of decoder 21 is connected to computer 25; and the third port of WDM device 17 is connected to the input of filter 18. The second output terminal of the wavelength division multiplexing device 17 is connected to the avalanche photodiode 22. The avalanche photodiode 22, the data acquisition card 23, and the decoder 24 are connected in series. The output terminal of the decoder 24 is connected to the computer 25. The encoder 9 is connected to the electro-optic modulator 11 and the electro-optic modulator 12 respectively. The encoder is an S-pulse encoder, that is, a pulse encoder using Simplex encoding (S-encoding) technology, which is used to modulate the optical signal into a pulse sequence optical signal to improve the signal gain.

[0030] In this embodiment, the monitoring system further includes a microwave signal generator 26, which is connected to an electro-optic modulator 10 and is used to modulate the optical signal into pulsed light.

[0031] In this embodiment, the wavelength division device 17 uses a wavelength division multiplexer to realize the multiplexing and transmission of multi-wavelength signals in a single fiber core, thereby reducing the occupation of optical fiber cores.

[0032] In this embodiment, preferably, the OPPC optical cable 5 contains at least two fiber cores.

[0033] In this embodiment, the narrow-line laser 1 is used to output a first beam (1550nm). The first beam serves as the optical signal for Brillouin scattering detection. The first beam enters the polarization controller 2, which ensures that the polarization direction of the input beam of the electro-optic modulator 10 is consistent with the transmission axis. After being modulated into pulsed light by the microwave-driven electro-optic modulator 10, the beam is amplified by the erbium-doped fiber amplifier 3. Then, the beam passes through the filter 4 to remove the spontaneous emission noise generated by the amplification of the erbium-doped fiber amplifier 3 before entering the optical cable (optical fiber) under test. The narrow-line laser 6 is used to output a second beam (1550nm). The second beam is split into a third beam and a fourth beam by a coupler 7. The third beam, as the pump light signal of Brillouin scattering, enters the polarization controller 8. After being modulated into a pulse beam by an electro-optic modulator 11 driven by an encoder 9 (using S-code encoding), it enters the polarization scrambler 13. Then, it is coupled with the Raman-scattered light signal by a coupler 14 and enters the erbium-doped fiber amplifier 15 for signal amplification. Then, it enters the optical cable (fiber) under test through a circulator 16 and a wavelength division multiplexing (WDM) device 17. The signal generated by the interaction between the probe light and the pump light in the fiber is transmitted back to the circulator 16 through the WDM device 17. After entering the filter 18 through the circulator 16, it is converted into an electrical signal by a photodetector 19. Then, the electrical signal is connected to a data acquisition card 20 to acquire the signal. Finally, the signal of fiber stress and temperature is detected by a decoder 21 and input into a computer 25 to obtain the final measurement value (i.e., the change in Brillouin frequency shift).

[0034] The fourth light, as a Raman scattered light signal, is modulated into a pulse sequence light signal by an electro-optic modulator 12 driven by an encoder (using S-code encoding). The pulse sequence light signal is coupled to the pump light by a coupler 14. The coupled light signal is amplified by an erbium-doped fiber amplifier 15 and then enters the optical cable (fiber) under test through a circulator 16 and a wavelength division multiplexing (WDM) device 17. At the same time, Stokes light and anti-Stokes light generated in the fiber by the pulse sequence light signal return to the WDM device 17 and are photoelectrically detected by an avalanche photodiode 22. The electrical signal is then connected to a data acquisition card 23 to acquire the signal. Finally, the fiber optic monitoring temperature signal is detected by a decoder 24 and input into a computer 25 to obtain the final measurement value (i.e., fiber optic temperature change data).

[0035] According to formula (1), the strain of the OPPC optical cable can be decoupled separately: (7); in, It is a constant. To measure the change in Brillouin frequency shift, It is a constant. This refers to the measured temperature change data of the optical fiber.

[0036] In this embodiment, the splitting ratio of the coupler 7 is 50:50.

[0037] The monitoring system provided by this utility model monitors fiber temperature based on Raman scattering (ROTDR); it monitors fiber temperature and stress changes based on Brillouin scattering; and finally, it monitors the measured temperature changes using a formula. By decoupling the stress change separately, the final values ​​of fiber temperature change and stress change are obtained, thus realizing decoupled monitoring of fiber stress and temperature.

[0038] In this invention, a wavelength division multiplexer is used to multiplex the optical fiber signal into one fiber core, which solves the problem of wasted fiber core resources caused by simultaneous monitoring of temperature and stress. Under normal circumstances, four fiber cores are required to monitor temperature and stress. With the wavelength division multiplexer, only two fiber cores are needed to monitor temperature and stress, saving the fiber cores occupied by monitoring.

[0039] In this invention, an S-pulse encoder is used to compensate for the inherent weakness of the Raman scattering signal, improve the signal-to-noise ratio, and increase the temperature monitoring length of the optical cable from 20km to 75km, thus meeting the measurement requirements of high-voltage transmission lines.

[0040] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A stress and temperature monitoring system for OPPC optical cables based on distributed optical fibers, characterized in that, Including a narrow-line laser I (1), a polarization controller I (2), an erbium-doped fiber amplifier I (3), a filter I (4), an OPPC optical cable (5), a narrow-line laser II (6), a coupler I (7), a polarization controller II (8), an encoder (9), an electro-optic modulator I (10), an electro-optic modulator II (11), an electro-optic modulator III (12), a polarization scrambler (13), a coupler II (14), an erbium-doped fiber amplifier II (15), a circulator (16), a wavelength division multiplexing device (17), a filter II (18), a photodetector (19), a data acquisition card I (20), a decoder I (21), an avalanche photodiode (22), a data acquisition card II (23), a decoder II (24), and a computer (25); The narrow-line laser (1), polarization controller (2), electro-optic modulator (10), erbium-doped fiber amplifier (3) and filter (4) are connected in series, and the output end of the filter (4) is connected to the OPPC optical cable (5). The narrow-line laser 2 (6) is connected to coupler 1 (7), the first output end of coupler 1 (7) is connected to polarization controller 2 (8), polarization controller 2 (8), electro-optic modulator 2 (11) and polarization scrambler (13) are connected in series, and the output end of polarization scrambler (13) is connected to the first input end of coupler 2 (14). The second output terminal of the first coupler (7) is connected to the third electro-optic modulator (12), and the third electro-optic modulator (12) is connected to the second input terminal of the second coupler (14). The output of the coupler 2 (14) is connected to the erbium-doped fiber amplifier 2 (15), which is connected to the OPPC optical cable (5) via the circulator (16) and the wavelength division multiplexing (WDM) device (17); the first output of the WDM device (17) is connected to the circulator (16), and the circulator (16), filter 2 (18), photodetector (19), data acquisition card 1 (20), and decoder 1 (21) are connected in series; the output of decoder 1 (21) is connected to the computer (25). The second output terminal of the wavelength division multiplexing device (17) is connected to the avalanche photodiode (22). The avalanche photodiode (22), the second data acquisition card (23), and the second decoder (24) are connected in series. The output terminal of the second decoder (24) is connected to the computer (25). The encoder (9) is connected to electro-optic modulator two (11) and electro-optic modulator three (12) respectively.

2. The OPPC optical cable stress and temperature monitoring system based on distributed optical fiber according to claim 1, characterized in that, The circulator (16) includes three ports: the first port is connected to the output of the second erbium-doped fiber amplifier (15), the second port is connected to the first output and / or the first input of the wavelength division multiplexing device (17), and the third port is connected to the input of the second filter (18).

3. The OPPC optical cable stress and temperature monitoring system based on distributed optical fiber according to claim 1, characterized in that, The narrow-line laser (1) is used to output the first light, which serves as the optical signal of the Brillouin scattering probe light. It passes through the polarization controller (2), the electro-optic modulator (10), the erbium-doped fiber amplifier (3), and the filter (4) in sequence before entering the optical cable under test. The narrow-line laser II (6) is used to output the second light. The second light is split into the third light and the fourth light by the coupler I (7). The third light is used as the light signal of the Brillouin scattering pump light. It passes through the polarization controller II (8), the electro-optic modulator II (11), the polarization scrambler (13), the coupler II (14) and the erbium-doped fiber amplifier II (15) in sequence, and then enters the optical cable under test through the circulator (16) and the wavelength division device (17). The probe light interacts with the pump light to detect the fiber stress and temperature. The fourth light, as a Raman scattered light signal, passes through the electro-optic modulator three (12), coupler two (14), erbium-doped fiber amplifier two (15) in sequence, and then enters the optical cable under test through the circulator (16) and wavelength division device (17) to detect the fiber temperature.

4. The OPPC optical cable stress and temperature monitoring system based on distributed optical fiber according to claim 3, characterized in that, The splitting ratio of the coupler (7) is 50:

50.

5. The OPPC optical cable stress and temperature monitoring system based on distributed optical fiber according to claim 1, characterized in that, The encoder (9) is an S-pulse encoder.

6. The OPPC optical cable stress and temperature monitoring system based on distributed optical fiber according to claim 1, characterized in that, The wavelength division multiplexing device (17) employs a wavelength division multiplexer.

7. The OPPC optical cable stress and temperature monitoring system based on distributed optical fiber according to claim 1, characterized in that, The OPPC optical cable (5) contains at least two fiber cores.

8. A stress and temperature monitoring system for OPPC optical cables based on distributed optical fibers according to any one of claims 1-7, characterized in that, It also includes a microwave signal generator (26), which is connected to an electro-optic modulator (10).

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