Search

CN-121984579-A - Multidimensional communication sensing system integrating optical transmission network and BOTDR/DAS distributed sensing

CN121984579ACN 121984579 ACN121984579 ACN 121984579ACN-121984579-A

Abstract

The invention discloses a multidimensional communication sensing system integrating an optical transmission network and BOTDR/DAS distributed sensing, and relates to the technical field of optical fiber communication and optical fiber sensing. The system comprises an OTN transmission subsystem, an optical fiber link and a BOTDR/DAS fusion sensing subsystem, wherein the OTN transmission subsystem is used for realizing high-capacity data transmission through the optical fiber link, and the BOTDR/DAS fusion sensing subsystem is used for realizing strain, temperature and vibration distributed measurement of the optical fiber link through a Brillouin scattering and Rayleigh backscattering mechanism. The system adopts a double self heterodyne demodulation architecture and a reverse wavelength division multiplexing mechanism, realizes the collaborative demodulation and high isolation transmission of BOTDR and DAS signals under the condition of common fiber, and can realize high-speed communication and distributed temperature, strain and vibration synchronous monitoring within the range of 100 km. The invention can lay a technical foundation for realizing the intellectualization of the physical layer of the in-service power OTN.

Inventors

  • DONG YONGKANG
  • LIU CHEN
  • ZHOU LIYING
  • ZHANG DAPEI
  • YANG XUECHENG
  • PENG XINNAN
  • TANG XIAOHUI
  • AN YIYAN
  • SHANG XIN
  • SHI HAIPENG
  • Ba dexin
  • XIA MENG
  • Sui Jinglin
  • LI BO

Assignees

  • 哈尔滨工业大学
  • 国网内蒙古东部电力有限公司电力科学研究院
  • 国家电网有限公司

Dates

Publication Date
20260505
Application Date
20251231

Claims (9)

  1. 1. The multidimensional communication sensing system integrating the optical transmission network and the BOTDR/DAS distributed sensing is characterized by comprising an OTN transmission subsystem (1), an optical fiber link (2) and a BOTDR/DAS fusion sensing subsystem (3), wherein the OTN transmission subsystem (1) is used for realizing high-capacity data transmission through the optical fiber link (2), and the BOTDR/DAS fusion sensing subsystem (3) is used for realizing strain, temperature and vibration distributed measurement of the optical fiber link (2) through a Brillouin scattering and Rayleigh backscattering mechanism; The BOTDR/DAS fusion perception subsystem (3) comprises a laser (31), a first coupler (32), an acousto-optic modulator (317), a first erbium-doped fiber amplifier (34), a first circulator (35), a second erbium-doped fiber amplifier (36), a second circulator (37), a fiber grating filter (38), a dense wavelength division multiplexer (39), a third coupler (310), a first balance detector (311), a second coupler (312), an electro-optic modulator (313), an orthogonal polarization switch (314), a fourth coupler (315), a second balance photoelectric detector (316), a band-pass filter (317), an envelope detector (318), a data acquisition card (319), a pulse generator (320) and a microwave signal source (321); the output end of the acousto-optic modulator (33) is connected with the input end of the first circulator (35), the second port (35-2) of the first circulator (35) is connected with the optical demultiplexer (15) of the OTN transmission subsystem (1), the third port (35-3) of the first circulator (35) is connected with the input end of the second erbium-doped fiber amplifier (36), the output end of the second erbium-doped fiber amplifier (36) is connected with the first port (37-1) of the second circulator (37), the second port (37-2) of the second circulator (37) is connected with the input end of the optical fiber filter (38), the third port (35-3) of the first circulator (35) is connected with the input end of the second erbium-doped fiber amplifier (36), and the output end of the optical fiber filter (38) is connected with the input end of the third multiplexer (310) of the optical fiber multiplexer (39); The output end of the second coupler (312) is respectively connected with the input ends of the third coupler (310) and the electro-optic modulator (313), the output end of the electro-optic modulator (313) is connected with the input end of the orthogonal polarization switch (314), the third port (37-3) of the second circulator (37) and the output end of the orthogonal polarization switch (314) are respectively connected with the input end of the fourth coupler (315), the output end of the fourth coupler (315) is connected with the input end of the second balanced photoelectric detector (316), the output end of the second balanced photoelectric detector (316) is connected with the input end of the band-pass filter (317), and the output end of the band-pass filter (317) is connected with the input end of the envelope detector (318); the output ends of the first balance detector (311) and the envelope detector (318) are respectively connected with a data acquisition card (319), the output end of the pulse generator (320) is connected with the input end of the acousto-optic modulator (33), and the output end of the microwave signal source (321) is connected with the input end of the electro-optic modulator (313).
  2. 2. The multi-dimensional communication perception system of integrated optical transmission network and BOTDR/DAS distributed sensing according to claim 1, wherein the OTN transmission subsystem (1) comprises a transmitting end (11), a transmitting end optical channel transmission unit (12), an optical multiplexer (13), an optical amplifier (14), an optical demultiplexer (15), a receiving end optical channel transmission unit (16) and a receiving end (17), wherein the transmitting end (11) is connected to an input end of the transmitting end optical channel transmission unit (12), an output end of the transmitting end optical channel transmission unit (12) is connected to an input end of the optical multiplexer (13), an output end of the optical multiplexer (13) is connected to an input end of the optical amplifier (14), an output end of the optical amplifier (14) is connected to an input end of the optical demultiplexer (15), an output end of the optical demultiplexer (15) is connected to an input end of the receiving end optical channel transmission unit (16), and an output end of the receiving end optical channel transmission unit (16) is connected to the receiving end (17).
  3. 3. The multi-dimensional communication perception system integrating optical transmission network and BOTDR/DAS distributed sensing according to claim 1 or 2, wherein the operation of the BOTDR/DAS fusion perception subsystem (3) comprises that the light output by the laser (31) is divided into upper branch light and lower branch light by the first coupler (32); the optical fiber transmission subsystem comprises an optical fiber link (2), an optical fiber grating filter (38), a fiber grating filter (39) and a fiber grating filter, wherein the optical fiber filter (33) is used for amplifying pump pulse light which is modulated into pump pulse light by the optical fiber modulator (33) and is led into frequency shift, the pump pulse light which is output by the optical fiber modulator (33) is amplified by the optical fiber modulator (320) and then injected into a first port (35-1) of the first circulator (35) by the optical fiber amplifier (34), and is coupled to a DWDM channel of an optical demultiplexer (15) of the OTN transmission subsystem (1) by a second port (35-2) of the first circulator (35); The down-branch light is divided into two paths by a second coupler (312), wherein one path of light is used as reference light of Rayleigh scattering, the reference light of Rayleigh scattering is mixed with the back-to-back scattered light filtered by a dense wavelength division multiplexer (39) through a third coupler (310) and then detected by a first balance detector (311), beat signals I and Q of the light are recorded by a data acquisition card (319), the other path of light of the down-branch light is used as reference light of Brillouin scattering, the reference light of Brillouin scattering is subjected to frequency modulation by an electro-optical modulator (313), the electro-optical modulator (313) is driven by a microwave signal source (321), the frequency modulated light output by the electro-optical modulator (313) is switched in polarization state by a quadrature polarization switch (314), reflected light output by a fiber grating filter (38) and the frequency modulated reference light after the polarization state is switched are mixed in a fourth coupler (315), and fixed frequency components of an external difference Brillouin signal are received by a second balance photoelectric detector (316), filtered by a band-pass filter (317) and detected by an envelope detector (318), and finally recorded by the data acquisition card (319).
  4. 4. The multi-dimensional communication perception system integrating optical transmission network and BOTDR/DAS distributed sensing as claimed in claim 1 or2, wherein said laser (31) is a narrow linewidth laser with linewidth of 3kHz and center wavelength of 1549.972nm, said fiber grating filter (38) has bandwidth of 0.08nm, center wavelength of 1550.06nm, and said dense wavelength division multiplexer (39) has center wavelength of 1549.972nm.
  5. 5. The multi-dimensional communication perception system of integrated optical transmission network and BOTDR/DAS distributed sensing according to claim 1 or 2, wherein the split ratio of the first coupler (32), the third coupler (310), the fourth coupler (315) is 50:50, and the split ratio of the second coupler (312) is 20:80.
  6. 6. The multi-dimensional communication sensing system for integrating optical transmission network and BOTDR/DAS distributed sensing according to claim 1 or 2, wherein the microwave signal emitted by the microwave signal source (321) sweeps in the range of 11.12-11.22GHz, steps by 4MHz, the center frequency of the band-pass filter (317) is 300 MHz, and the bandwidth is 100 MHz.
  7. 7. The multi-dimensional communication perception system integrating optical transmission network and BOTDR/DAS distributed sensing as claimed in claim 2, wherein the OTN transmission subsystem (1) adopts OTN configuration with single channel rate of 100 Gbit/s, works in C band based on polarization multiplexing QPSK coherent receiving modulation format, adopts 88 wave DWDM scheme, has channel interval of 50 GHz, and each wavelength channel independently carries different data service.
  8. 8. The system of claim 3, wherein the upper branch light is used as a probe pulse light, and the lower branch light is used as local oscillation light of the BOTDR and DAS respectively, and the probe pulse light is expressed as: ; In the formula, Representing the amplitude of the probe pulse light; representing the frequency of the laser (31); Indicating the frequency shift introduced by the acousto-optic modulator (33), t indicating the time; indicating an initial phase of the probe pulse light; The local oscillation light of the BOTDR and DAS are respectively expressed as And : ; ; In the formula, And Respectively representing the amplitudes of Brillouin local oscillation light and Rayleigh Li Benzhen light; 、 Respectively representing initial phases of Brillouin local oscillation light and Rayleigh Li Benzhen light; the total optical field of the back-scattered signal light returned by the optical fiber link (2) is expressed as: ; In the formula, 、 And Respectively Rayleigh scattered light, brillouin Stokes light and Brillouin anti-Stokes light, wherein: ; ; ; Wherein the method comprises the steps of 、 And The magnitudes of the Rayleigh scattered light, the Brillouin scattered Stokes light and the Brillouin scattered anti-Stokes light are shown, respectively; representing the brillouin shift; 、 、 the phase differences of the Rayleigh scattering light, the Brillouin scattering Stokes light and the Brillouin scattering anti-Stokes light and the corresponding local oscillator light are respectively shown; 、 、 the initial phases of the Rayleigh scattered light, the Brillouin Stokes scattered light and the Brillouin anti-Stokes scattered light, respectively.
  9. 9. The integrated optical transmission network and BOTDR/DAS distributed sensing multidimensional communication sensing system of claim 8, wherein the optical signal output by the first balanced detector (311) is represented by: ; The optical signal output by the second balanced photodetector (316) is represented as: ; In the formula, And The power of the Rayleigh scattered light and the power of the self-Brillouin scattered light are respectively represented; The representation is proportional; And The powers of the brillouin local oscillator light and the rayleigh Li Benzhen light are respectively represented.

Description

Multidimensional communication sensing system integrating optical transmission network and BOTDR/DAS distributed sensing Technical Field The invention relates to the technical field of optical fiber communication and optical fiber sensing, in particular to a multidimensional communication sensing system integrating an optical transmission network and BOTDR/DAS distributed sensing. Background With the rapid development of new power systems and smart grids, the power communication network is not limited to the traditional information transmission function, but gradually evolves into a core neural center supporting real-time monitoring, dynamic control, differential protection and intelligent decision of the power grid. In this architecture, the optical transport network (Optical Transport Network, OTN) has become a key support technology for the power backbone communication network by virtue of its ultra-high reliability, ultra-large bandwidth and low latency characteristics. However, the physical safety of OTN is greatly dependent on the long-term stable operation of the aerial composite optical cable (such as OPGW/OPPC), and these optical cables are continuously affected by multiple coupling effects such as icing, ice melting, wind vibration, day-night temperature difference, extreme climate, etc., and are prone to cause mechanical fatigue, optical fiber attenuation and material aging, and even cause fiber breakage, wire breakage or tower collapse in severe cases, which constitutes a direct threat to the safety and stability of the power system. Therefore, real-time, accurate and full life cycle monitoring of the physical state of the aerial optical cable is realized, and the real-time, accurate and full life cycle monitoring of the physical state of the aerial optical cable is an urgent need for guaranteeing the toughness of power communication and the safe operation of a smart power grid. In recent years, the optical fiber distributed sensing (Distributed Fiber Optic Sensing, DFOS) technology gradually becomes an important means for sensing the state of a power transmission line due to the advantages of long-distance coverage, full-distribution measurement, no electromagnetic interference and the like. The typical scheme comprises a BOTDR/BOTDA system based on Brillouin scattering, high-precision reconstruction of optical fiber strain and a temperature field can be realized through the spatial distribution of Brillouin frequency shift, frequency shift differences of different optical cable sections can be used for identifying fusion points and joint positions, external load changes or abnormal elongation are expressed as abnormal optical fiber strain and can be used for sag monitoring and icing load assessment, and transient state high Wen Shijian (such as ice melting current or lightning stroke) can cause local Brillouin frequency shift mutation, so that real-time detection of abnormal optical cable temperature is realized. In addition, studies have been made to further identify ice-covered areas using temperature phase differences, exhibiting good engineering application potential. Distributed acoustic wave sensing (DAS) or phase sensitive optical time domain reflectometry (phi-OTDR) based on Rayleigh scattering can sensitively detect optical cable micro-vibration, and galloping behaviors, vibration modes and ice coating thickness estimation are realized. Brillouin scattering and rayleigh scattering have advantages and limitations in terms of perceived physical quantity and space-time resolution, and the former precisely quantifies temperature and strain, but have limited dynamic response, and the latter highly sensitively captures rapid vibrations, but is difficult to provide quantitative temperature/strain information. Therefore, a single mechanism is difficult to comprehensively describe the real physical state of the optical cable, and full sensing of temperature, strain and vibration can be realized on macroscopic-microscopic and multi-time-scale dimensions only by cooperatively applying two distributed sensing technologies, namely Brillouin and Rayleigh, so that the accuracy of diagnosis of abnormal events of the optical cable is ensured. Meanwhile, as the power communication network evolves to a high speed, an intelligent and a long distance direction, optical fiber resources are increasingly strained. Although the optical cable is deployed in a huge scale, the fiber core resources are mainly used for bearing backbone communication services, redundant space is continuously compressed, and reserving independent optical fibers as sensing channels is difficult to meet service bandwidth requirements, and resource waste is caused. In a backbone OTN network with high traffic density, the communication traffic occupies almost all the core resources, and it is difficult to open up a physical channel for the sensing link alone. Therefore, realizing the common fiber operation of communication and perceptio