A device and method for synchronously measuring strain and attenuation of optical fiber in OPLC flattening experiment

Abstract

The present invention discloses a device and method for synchronously measuring strain and attenuation of optical fiber in an OPLC flattening experiment. The method comprises the steps of: connecting the OPLC conductors to form a loop, injecting different load currents by using a cable heating device, placing a thermocouple in the OPLC to measure the temperature of the conductor and the optical fiber unit position; placing the OPLC on the platform base of the flattening device, lifting and lowering the movable platform to apply different flattening forces; connecting one optical fiber in the OPLC to a light source and an optical power meter, using an insertion loss method to test the optical fiber attenuation, and connecting another optical fiber to an optical fiber temperature strain analyzer to implement temperature strain testing; changing the load current, applying different flattening forces to the OPLC, recording the changes in temperature, optical power and Brillouin frequency, and synchronously obtaining the optical fiber strain and optical fiber attenuation under different temperatures and different flattening forces of the OPLC by calculation. The present invention solves the technical problem of synchronous measurement of optical fiber strain and attenuation under different loads and different flattening forces of the OPLC through the coordinated design of different experimental devices of the OPLC.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical fiber attenuation loss testing in an OPLC flattening experiment of an optical fiber composite low-voltage cable of 1 kV (Um=1.2 kV) or less, and specifically relates to a device and method for synchronously measuring optical fiber strain and attenuation in an OPLC flattening experiment. Background Art

[0002] OPLC is a cable composed of an insulated core and an optical transmission unit that has the ability to transmit electric energy and optical communication. It can provide power and information transmission at the same time and is suitable for power projects with a rated voltage of 0.6 / 1(1.2)kV and below. OPLC makes it possible to integrate the complex engineering of laying multiple lines such as electric wires, network cables, telephone lines, and cable TV lines into an integrated construction, realizing the integration of four networks. It not only simplifies the installation process, but also greatly saves line resources and pipeline resources. At the same time, it has advantages in informatization, automation, and interactivity, and is the mainstream terminal product of the "smart grid".

[0003] The purpose of the flattening test on OPLC is to determine the ability of the composite cable to withstand flattening. For a section of composite cable sufficient to implement the specified flattening test, the sample is flattened between a flat steel plate base and a movable steel plate, and different flattening forces are applied. After maintaining for 1 minute, monitoring is carried out, and then the flattening force is gradually removed. After 5 minutes, the final monitoring is carried out. The usual qualification criteria are that the optical fiber does not break and the optical fiber attenuation change does not exceed the value specified in the specification. At present, there is a method for detecting the attenuation of optical fibers in OPLC cables under external flattening forces, but it cannot be applied to the synchronous measurement of optical fiber attenuation and optical fiber strain in OPLC cables under different external flattening forces, different load currents, and different temperatures. Therefore, the inability of existing testing equipment to synchronously measure optical fiber strain and optical fiber attenuation for OPLC flattening experiments is a technical problem that technical personnel in this field need to solve. Summary of the invention

[0004] The purpose of the present invention is to address the deficiencies of the above-mentioned prior art and to provide a device and method for synchronously measuring strain and attenuation of optical fiber in an OPLC flattening experiment.

[0005] The present invention is achieved by adopting the following technical solutions:

[0006] A device for synchronously measuring strain and attenuation of optical fiber in OPLC flattening experiment, comprising a thermocouple, a thermocouple recorder, a light source, an optical power meter, an optical power recorder, an optical fiber temperature strain analyzer, a pressure test bench, and a high current generator; wherein,

[0007] During measurement, the OPLC to be tested passes through a large current generator, and conductors at both ends of the OPLC to be tested are connected to form an energized circuit; a thermocouple is embedded in the OPLC to be tested, and is used to measure the temperature of the OPLC to be tested at different times; the OPLC to be tested is set on a pressure test bench, and a flattening force is applied to the OPLC to be tested through the pressure test bench; both ends of an optical fiber in the OPLC to be tested are respectively connected to a light source and an optical power meter to form an optical path; both ends of another optical fiber in the OPLC to be tested are respectively connected to two ports of an optical fiber temperature strain analyzer to form another optical path; the magnitude of the current generated for the OPLC to be tested is adjusted through the large current generator; the thermocouple and the optical power meter are respectively connected to a thermocouple recorder and an optical power recorder, the thermocouple recorder is used to store the temperature values ​​of each structure of the OPLC to be tested measured by the thermocouple at different times, the optical power meter is used to collect optical power values ​​at different times, and the optical power measured each time is stored through the optical power recorder; the optical fiber temperature strain analyzer is used to collect the Brillouin frequencies of different positions of the OPLC to be tested at different times.

[0008] A further improvement of the present invention is that the OPLC to be tested includes an outer sheath and a wrapping tape arranged in sequence from the outside to the inside, and an optical unit and a plurality of conductors arranged in the wrapping tape, each conductor is provided with insulation in the circumferential direction, and fillers are provided between the conductors and between the conductors and the optical unit.

[0009] A further improvement of the present invention is that the pressure testing bench includes a fixture column, a pressure gauge, a pressure gauge fixing block, a movable steel plate, a fixing platform and a control panel; wherein the pressure gauge is connected to the pressure gauge fixing block and fixed on the fixture column, the movable steel plate is fixed to the bottom of the pressure gauge by a fixture, and the control panel and the fixing platform are located below the fixture column.

[0010] A further improvement of the present invention is that the light source is a monochromatic light source for generating white light with a wavelength of 1550nm; the optical power meter is a photodetector capable of detecting light wavelengths in the range of 185-25000nm; and the optical fiber temperature strain analyzer is an optical time domain analyzer based on Brillouin scattering, i.e., an optical fiber temperature strain analyzer.

[0011] A method for synchronously measuring strain and attenuation of optical fiber in OPLC flattening experiment, characterized in that the method is based on the above-mentioned device for synchronously measuring strain and attenuation of optical fiber in OPLC flattening experiment, and comprises the following steps:

[0012] 1) Pass an OPLC to be tested through a large current generator and connect the conductors at both ends of the OPLC to be tested to form a power-on loop; punch a hole in the OPLC to be tested, insert a thermocouple, and measure the temperature of the OPLC to be tested at different times; place the OPLC to be tested on a pressure test bench to apply a flattening force to the OPLC to be tested;

[0013] 2) Connect the two ends of one of the optical fibers in the OPLC to be tested to the light source and the optical power meter to form an optical path; connect the two ends of another optical fiber in the OPLC to be tested to the two ports of the optical fiber temperature strain analyzer to form another optical path;

[0014] 3) Changing the magnitude of the current passing through the OPLC to be tested, applying different flattening forces to the OPLC to be tested, and recording the temperature measured by the thermocouple, the optical power measured by the optical power meter, and the Brillouin frequency measured by the optical fiber temperature strain analyzer under different currents;

[0015] 4) According to the relationship between Brillouin frequency, temperature and strain, and the relationship between fiber attenuation and optical power, the strain and attenuation values ​​of the optical fiber under different flattening forces of the OPLC to be tested at the same time are obtained.

[0016] A further improvement of the present invention is that the specific implementation method of step 1) is as follows:

[0017] The structure of the OPLC to be tested includes a conductor, insulation, an optical unit, a filler, a wrapping tape and an outer sheath. When punching the OPLC to be tested, the conductor and the optical unit in the OPLC to be tested should be exposed, and the thermocouple is respectively contacted with the conductor and the optical unit to measure the temperature of each structure of the OPLC to be tested; the thermocouple is connected to a thermocouple recorder to store the temperature values ​​of each structure of the OPLC to be tested measured by the thermocouple at different times;

[0018] The pressure test bench includes a fixture column, a pressure gauge, a pressure gauge fixing block, a movable steel plate, a fixing table and a control panel; wherein the pressure gauge is connected to the pressure gauge fixing block and fixed on the fixture column, the movable steel plate is fixed to the bottom of the pressure gauge through the fixture, and the control panel and the fixing table are below the fixture column; the OPLC to be tested is placed on the fixing table, and the height of the pressure gauge and the movable steel plate is changed by moving the position of the pressure gauge fixing block on the fixture column, and the size of the flattening force transmitted to the OPLC to be tested by the pressure gauge through the movable steel plate is adjusted through the control panel.

[0019] A further improvement of the present invention is that the specific implementation method of step 2) is as follows:

[0020] In order to perform optical fiber attenuation detection on the optical fiber in the OPLC to be tested, the two ends of one of the optical fibers in the OPLC to be tested are fused with the FC / APC single-mode optical fiber jumper, so that the light generated by the light source is transmitted to the optical power meter through the optical fiber in the OPLC to be tested to measure the optical power; another optical fiber in the OPLC to be tested that is different from the one connected to the light source and the optical power meter is connected to the two connectors of the optical fiber temperature strain analyzer through the FC / APC single-mode optical fiber jumper to form an optical path.

[0021] A further improvement of the present invention is that the specific implementation method of step 3) is as follows:

[0022] Control the magnitude of the current generated by the large current generator to the OPLC to be tested; observe the conductor temperature measured by the thermocouple when the current is stable at a value, and when the conductor temperature is stable at a constant value, adjust the magnitude of the flattening force applied by the pressure test bench, record the magnitude of the optical power measured by the optical power meter under different flattening forces, and use the optical fiber temperature strain analyzer to measure the Brillouin frequency of the optical fiber in the OPLC to be tested at this time;

[0023] The optical power meter collects the optical power values ​​at different times, is connected to the optical power recorder, and stores the optical power measured each time in the optical power recorder; the optical fiber temperature strain analyzer obtains the Brillouin frequency of the optical fiber at different positions in the OPLC to be tested when the optical path is connected. The optical fiber temperature strain analyzer contains built-in software for storing the Brillouin frequency of the optical fiber at different positions. The Brillouin frequency of the optical fiber in the OPLC to be tested measured at different times is stored through the software in the optical fiber temperature strain analyzer.

[0024] A further improvement of the present invention is that the specific implementation method of step 4) is as follows:

[0025] The optical fiber temperature strain analyzer measures the Brillouin frequency of the optical fiber at different positions in the OPLC to be tested after the conductor is stable under different currents. The relationship between the Brillouin frequency and the temperature and strain of the optical fiber at the same time is shown in formula (1):

[0026] v B (T,ε)=v B (T 0 ,ε 0 )+C υT (TT 0 )+C υε (ε-ε 0 ) (1)

[0027] where v B (T 0 ,ε 0 ),v B (T, ε) is the frequency shift of the Brillouin scattered light in the optical fiber in the cable measured by the optical fiber temperature strain analyzer when there is no current in the conductor of the OPLC to be tested, when there is current in the conductor and the temperature of the conductor is stable, ε 0 , ε is the strain value of the optical fiber in the cable measured when there is no current in the conductor of the OPLC to be tested, the conductor has current and the conductor temperature is stable, T 0 , T is the temperature value of the optical fiber in the cable measured when there is no current in the conductor of the OPLC to be tested, the conductor has current and the conductor temperature is stable, C vT , C vεThey are the Brillouin frequency shift temperature coefficient and the Brillouin frequency shift strain coefficient respectively; the Brillouin frequency under different currents is measured by the optical fiber temperature strain analyzer and the temperature value measured by the thermocouple, and then the difference between the optical fiber strain when the conductor temperature is stable under the condition of current and the optical fiber strain when there is no current is calculated;

[0028] The fiber attenuation generated during the operation of the OPLC to be tested is obtained from the optical power. When no current passes through the conductor in the OPLC to be tested, an optical power is obtained. When current passes through the conductor and the conductor temperature stabilizes, the optical power under this condition can be obtained. Ten times the logarithm of the two optical power values ​​is the fiber attenuation of the optical fiber in the OPLC under this current. The relationship between optical power and fiber attenuation is shown in formula (2):

[0029]

[0030] Where P 1 is the optical power value measured when there is no current in the conductor of the OPLC to be tested, P 2 It is the optical power value measured after the conductor in the OPLC to be tested has current and the conductor temperature is stable.

[0031] The present invention has the following beneficial technical effects:

[0032] The present invention provides a device for synchronously measuring the strain and attenuation of optical fiber in an OPLC flattening experiment, which comprises an optical fiber temperature strain analyzer, a light source, a large current generator, an optical power meter, a recorder, a thermocouple and a pressure test bench. The device can detect the temperature of each structure under different currents when different flattening forces are applied to the OPLC, and can also detect the strain and optical power of the optical fiber in the cable.

[0033] The present invention provides a method for synchronously measuring the strain and attenuation of optical fiber in an OPLC flattening experiment, which realizes the synchronous detection of the temperature of each structure of the OPLC cable under different currents and the strain and optical power of the optical fiber under different flattening forces, and solves the technical problem of synchronously measuring the strain and attenuation of the optical fiber under different loads and different flattening forces of the OPLC. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Attached Figure 1 This is a schematic diagram of the device for synchronous measurement of optical fiber strain and attenuation in OPLC flattening experiment.

[0035] Attached Figure 2 It is a schematic diagram of the OPLC structure to be tested.

[0036] Attached Figure 3 It is a schematic diagram of the structure of the pressure test bench.

[0037] Attached Figure 4 This is the block diagram of the synchronous detection of optical fiber strain and optical fiber attenuation under different flattening forces of OPLC.

[0038] Attached Figure 5 It is the optical fiber temperature curve corresponding to different currents.

[0039] Attached Figure 6 It is the Brillouin frequency curve of optical fiber under different currents and different flattening forces.

[0040] Attached Figure 7 It is a fiber strain difference curve of the fiber under different currents and different flattening forces.

[0041] Attached Figure 8 It is the optical fiber attenuation curve of the optical fiber under different currents and different flattening forces.

[0042] Description of reference numerals:

[0043] 1 is a thermocouple, 2 is a thermocouple recorder, 3 is a light source, 4 is an optical power meter, 5 is an optical power recorder, 6 is an optical fiber temperature strain analyzer, 7 is a pressure test bench, 8 is a large current generator, 9 is an OPLC to be tested, 701 is a fixture column, 702 is a pressure gauge, 703 is a pressure gauge fixing block, 704 is a movable steel plate, 705 is a fixing table, 706 is a control panel, 901 is a conductor, 902 is an insulation, 903 is an optical unit, 904 is a filler, 905 is a wrapping tape, and 906 is an outer sheath. DETAILED DESCRIPTION

[0044] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0045] like Figures 1 to 3 As shown, the present invention provides a device for synchronously measuring the strain and attenuation of an OPLC flattening experiment optical fiber, comprising an optical fiber temperature strain analyzer 6, a light source 4, an OPLC to be tested 9, a large current generator 8, an optical power meter 4, an optical power recorder 5, a thermocouple 1, a thermocouple recorder 2 and a pressure test bench 7.

[0046] During measurement, the OPLC 9 to be tested passes through the large current generator 8, and the conductors at both ends of the OPLC 9 to be tested are connected to form an energized circuit; the thermocouple 1 is embedded in the OPLC 9 to be tested, and is used to measure the temperature of the OPLC 9 to be tested at different times; the OPLC 9 to be tested is set on the pressure test bench 8, and the pressure test bench 8 is used to apply a flattening force to the OPLC 9 to be tested; the two ends of one optical fiber in the OPLC 9 to be tested are respectively connected to the light source 3 and the optical power meter 4 to form an optical path; the two ends of another optical fiber in the OPLC 9 to be tested are respectively connected to the two ports of the optical fiber temperature strain analyzer 6 to form another optical path; the voltage regulator 17 is used to control the large current generator 8 to the OPLC to be tested 9, and the current size is obtained through the indication of the current transformer 22; the thermocouple 1 and the optical power meter 4 are respectively connected to the optical power recorder 5, and the thermocouple recorder 2 is used to store the temperature values ​​of each structure of the OPLC to be tested measured by the thermocouple 1 at different times; the optical power meter 4 can collect the optical power values ​​at different times, and store the optical power measured each time through the optical power recorder 5.

[0047] like Figure 4 As shown, the method for synchronously measuring strain and attenuation of optical fiber in OPLC flattening experiment provided by the present invention comprises the following steps:

[0048] 1) An OPLC 9 to be tested is passed through a large current generator 8, and conductors 1 at both ends of the OPLC 9 to be tested are connected to form a power circuit; a hole is punched on the OPLC 9 to be tested, and a thermocouple 1 is placed in the hole to measure the temperature of the OPLC 9 to be tested at different times; the OPLC 9 to be tested is placed on a fixed table 705 of a pressure test table 8, and a flattening force is applied to the OPLC 9 to be tested by using a movable steel plate 704.

[0049] 2) Connect the two ends of one optical fiber in the OPLC 9 to be tested to the light source 3 and the optical power meter 4 to form an optical path; connect the two ends of another optical fiber in the OPLC 9 to be tested to the two ports of the optical fiber temperature strain analyzer 6 to form another optical path.

[0050] 3) Changing the magnitude of the current passed through the OPLC 9 by the large current generator 8, applying different flattening forces to the OPLC 9, and recording the temperature measured by the thermocouple 1, the optical power measured by the optical power meter 4, and the Brillouin frequency measured by the optical fiber temperature strain analyzer 6 under different currents.

[0051] 4) According to the relationship between Brillouin frequency, temperature and strain, and the relationship between fiber attenuation and optical power, the strain and attenuation values ​​of the optical fiber under different flattening forces of the OPLC 9 to be tested at the same time are obtained.

[0052] Step 1) Take the OPLC 9 to be tested of OPLC-WDZ-YJY-0.6 / 1kV-3*10+GQ-2B6a as the research object. The structure of the OPLC 9 to be tested includes a conductor 901, an insulation 902, an optical unit 903, a filling 904, a wrapping tape 905 and an outer sheath 906. The schematic diagram of the structure of the OPLC 9 to be tested is as follows: Figure 2 When drilling holes in the OPLC 9 to be tested, the conductor and the optical unit in the OPLC 9 to be tested should be exposed, and the thermocouple 1 is respectively in contact with the conductor 901 and the optical unit 903 to measure the temperature of each structure of the OPLC 9 to be tested. The thermocouple 1 is connected to the thermocouple recorder 2 to store the temperature values ​​of each structure of the OPLC 9 to be tested measured by the thermocouple 1 at different times.

[0053] The pressure test bench 8 includes a fixture column 701, a pressure gauge 702, a pressure gauge fixing block 703, a movable steel plate 704, a fixing platform 705 and a control panel 706. The length of the movable steel plate 704 is 100 mm. The movable steel plate 704 is fixed to the pressure gauge 702 by a fixture. The pressure gauge 702 is connected to the pressure gauge fixing block 703 and fixed to the fixture column 701. Below the fixture column 701 are the control panel 706 and the fixing platform 705. The OPLC 9 to be tested is placed on the fixing platform 705, and the height of the pressure gauge 702 and the movable steel plate 704 is changed by moving the position of the pressure gauge fixing block 703 on the fixture column 701. The size of the flattening force transmitted by the pressure gauge 702 to the OPLC 9 to be tested through the movable steel plate 704 is adjusted by the control panel 706. The structural schematic diagram of the pressure test bench 702 is shown in FIG. Figure 3 shown.

[0054] Step 2) is to perform optical fiber attenuation detection on the optical fiber in the OPLC 9 to be tested, and the two ends of one of the optical fibers in the OPLC 9 to be tested are fused with FC / APC single-mode optical fiber jumpers, so that the light generated by the light source 3 is transmitted to the optical power meter 4 through the optical fiber in the OPLC 9 to be tested to measure the size of the optical power. The light source 3 is a Fiberlabs ASE-1550-25 light source, which is used to generate white light with a wavelength of 1550nm, and the optical power meter 4 is a PM320E optical power meter of Thorlabs, which detects the light wavelength range of 185-25000nm. Another optical fiber in the OPLC 9 to be tested that is different from the connection light source 3 and the optical power meter 4 is connected to the two connectors of the optical fiber temperature strain analyzer 6 through the FC / APC single-mode optical fiber jumper to form an optical path. The optical fiber temperature strain analyzer 6 is an Omnisens DITEST STA-R optical fiber temperature strain analyzer, which is a distributed temperature strain detection system based on the Brillouin optical time domain analysis principle, and detects the optical fiber temperature and strain distribution at different positions of the optical fiber in the OPLC 9 to be tested. The length of the optical fiber in the OPLC 9 to be tested used in the test is 10 meters, and the Brillouin frequency at different positions of the axial optical fiber in the cable can be measured by the analyzer.

[0055] Step 3) The synchronous detection system of optical fiber strain and optical fiber attenuation of the OPLC 9 to be tested under different flattening forces includes an optical fiber temperature strain analyzer 6, a light source 3, an OPLC 9 to be tested, a large current generator 8, an optical power meter 4, an optical power recorder 19, a thermocouple 1, a thermocouple recorder 2 and a pressure test bench 8. The large current generator 8 is controlled to change the magnitude of the current generated for the OPLC 9 to be tested. The current value is maintained at 20A, 40A, 60A, 80A, and 100A respectively. When the current is stable at a value, the conductor temperature measured by the thermocouple 1 is observed. When the conductor temperature is stable at a constant value, the flattening force applied by the pressure test bench 8 is adjusted to 200N, 300N, and 400N respectively, and the optical power measured by the optical power meter 4 under different flattening forces is recorded, and the Brillouin frequency of the optical fiber in the OPLC 9 to be tested is measured by the optical fiber temperature strain analyzer 6.

[0056] The optical power meter 4 can collect the optical power values ​​at different times, and is connected to the thermocouple recorder 19 to store the optical power measured each time in the optical power recorder 5. The optical fiber temperature strain analyzer 6 can obtain the Brillouin frequency of the optical fiber at different positions in the OPLC 9 to be tested when the optical path is connected. The optical fiber temperature strain analyzer 6 contains built-in software that can store the Brillouin frequency of the optical fiber at different positions. The Brillouin frequency of the optical fiber in the OPLC 9 to be tested measured at different times can be stored by the software in the optical fiber temperature strain analyzer 6. The schematic diagram of the synchronous detection system of optical fiber strain and optical fiber attenuation of the OPLC 9 to be tested under different flattening forces is shown in FIG. Figure 4 As shown in Figure 2, the fiber temperature curves corresponding to different currents are as follows: Figure 5 As shown in Figure 2, the Brillouin frequency curves of the optical fiber in the OPLC 9 under different currents under different squeezing forces are shown in Figure 2. Figure 6 shown.

[0057] Step 4) The optical fiber temperature strain analyzer 6 can measure the Brillouin frequency of the optical fiber at different positions in the OPLC 9 to be tested after the conductor is stable under different currents. The relationship between the Brillouin frequency and the temperature and strain of the optical fiber at the same time is shown in formula (1):

[0058] v B (T,ε)=v B (T 0 ,ε 0 )+C υT (TT 0 )+C υε (ε-ε 0 ) (1)

[0059] where v B (T 0 ,ε 0 ),v B (T, ε) is the frequency shift of the Brillouin scattered light of the optical fiber in the cable measured by the optical fiber temperature strain analyzer when there is no current in the conductor of the OPLC 9 to be tested, the conductor has current and the conductor temperature is stable, ε 0 , ε is the strain value of the optical fiber in the cable measured when there is no current in the conductor of the OPLC 9 to be tested, the current in the conductor and the temperature of the conductor is stable, T 0 , T is the temperature value of the optical fiber in the cable measured when there is no current in the conductor of the OPLC 9 to be tested, the current in the conductor and the temperature of the conductor is stable, C vT , C vε are respectively the Brillouin frequency shift temperature coefficient and the Brillouin frequency shift strain coefficient; the Brillouin frequency under different currents is measured by the optical fiber temperature strain analyzer 6 and the temperature value measured by the thermocouple 1, and the difference between the optical fiber strain when the conductor temperature is stable under the condition of current and the optical fiber strain when there is no current can be calculated. The optical fiber strain difference curves of the optical fiber in the OPLC 9 to be tested under different currents under different flattening forces are shown in Figure 7 shown.

[0060] The optical fiber attenuation generated during the operation of the OPLC 9 to be tested is obtained from the optical power. When no current passes through the conductor in the OPLC 9 to be tested, an optical power is obtained. When the current passes through the conductor and the conductor temperature is stable, the optical power under this condition can be obtained. After calculating the optical power, the optical fiber attenuation when the conductor passes through the current can be obtained. The relationship between the optical power and the optical fiber attenuation is shown in formula (2):

[0061]

[0062] Where P1 is the optical power value measured when there is no current in the conductor of the OPLC 9 to be tested, P 2 is the optical power value measured when the conductor in the OPLC 9 to be tested has current and the conductor temperature is stable. The optical fiber attenuation curves of the optical fiber in the OPLC 9 to be tested under different currents and different compression forces are shown in Figure 8 shown.

Claims

1. A method for synchronously measuring strain and attenuation of optical fiber in OPLC flattening experiment, characterized in that: The method is based on a device for synchronously measuring strain and attenuation of optical fiber in an OPLC flattening experiment, the device comprising a thermocouple (1), a thermocouple recorder (2), a light source (3), an optical power meter (4), an optical power recorder (5), an optical fiber temperature strain analyzer (6), a pressure test bench (7), and a large current generator (8); wherein, During measurement, the OPLC (9) to be tested passes through a large current generator (8), and the conductors at both ends of the OPLC (9) to be tested are connected to form an energized circuit; a thermocouple (1) is embedded in the OPLC (9) to be tested, and is used to measure the temperature of the OPLC (9) to be tested at different times; the OPLC (9) to be tested is set on a pressure test bench (7), and a flattening force is applied to the OPLC (9) to be tested through the pressure test bench (7); the two ends of an optical fiber in the OPLC (9) to be tested are respectively connected to a light source (3) and an optical power meter (4) to form an optical path; the two ends of another optical fiber in the OPLC (9) to be tested are respectively connected to the optical fiber temperature strain analyzer (6) The two ports are connected to form another optical path; the magnitude of the current generated by the OPLC (9) to be tested is adjusted by a large current generator (8); the thermocouple (1) and the optical power meter (4) are respectively connected to a thermocouple recorder (2) and an optical power recorder (5); the thermocouple recorder (2) is used to store the temperature values ​​of each structure of the OPLC (9) to be tested measured by the thermocouple (1) at different times; the optical power meter (4) is used to collect optical power values ​​at different times, and the optical power measured each time is stored through the optical power recorder (5); the optical fiber temperature strain analyzer (6) is used to collect the Brillouin frequencies of different positions of the OPLC (9) to be tested at different times; The method comprises the following steps: 1) passing an OPLC (9) to be tested through a large current generator (8), and connecting the conductors at both ends of the OPLC (9) to be tested to form an electric circuit; drilling a hole in the OPLC (9) to be tested, inserting a thermocouple (1), and measuring the temperature of the OPLC (9) to be tested at different times; placing the OPLC (9) to be tested on a pressure test bench (7) to apply a flattening force to the OPLC (9) to be tested; 2) connecting the two ends of one optical fiber in the OPLC (9) to be tested to the light source (3) and the optical power meter (4) respectively to form an optical path; connecting the two ends of another optical fiber in the OPLC (9) to be tested to the two ports of the optical fiber temperature strain analyzer (6) respectively to form another optical path; 3) changing the magnitude of the current passing through the OPLC (9) to be tested, applying different flattening forces to the OPLC (9) to be tested, and recording the temperature measured by the thermocouple (1), the optical power measured by the optical power meter (4), and the Brillouin frequency measured by the optical fiber temperature strain analyzer (6) under different currents; 4) Based on the relationship between Brillouin frequency, temperature and strain, and the relationship between fiber attenuation and optical power, the strain and attenuation values ​​of the optical fiber under different compression forces of the OPLC (9) to be tested at the same time are obtained.

2. The method for synchronously measuring strain and attenuation of optical fiber in OPLC flattening experiment according to claim 1, characterized in that: The specific implementation method of step 1) is as follows: The structure of the OPLC (9) to be tested comprises a conductor (901), an insulation (902), an optical unit (903), a filler (904), a wrapping tape (905) and an outer sheath (906). When the OPLC (9) to be tested is punched, the conductor (901) and the optical unit (903) in the OPLC (9) to be tested are exposed, and a thermocouple (1) is respectively contacted with the conductor (901) and the optical unit (903) to measure the temperature of each structure of the OPLC (9) to be tested; the thermocouple (1) is connected to a thermocouple recorder (2) to store the temperature values ​​of each structure of the OPLC (9) to be tested measured by the thermocouple (1) at different times; The pressure test bench (7) comprises a fixture column (701), a pressure gauge (702), a pressure gauge fixing block (703), a movable steel plate (704), a fixing platform (705) and a control panel (706); wherein the pressure gauge (702) is connected to the pressure gauge fixing block (703) and fixed on the fixture column (701); the movable steel plate (704) is fixed to the bottom of the pressure gauge (702) by a fixture; and the control panel (706) and the fixing platform (705) are located below the fixture column (701); an OPLC (9) to be tested is placed on the fixing platform (705), and the height of the pressure gauge (702) and the movable steel plate (704) is changed by moving the position of the pressure gauge fixing block (703) on the fixture column (701); and the magnitude of the flattening force transmitted from the pressure gauge (702) to the OPLC (9) to be tested through the movable steel plate (704) is adjusted by the control panel (706).

3. The method for synchronously measuring strain and attenuation of optical fiber in OPLC flattening experiment according to claim 2, characterized in that: The specific implementation method of step 2) is as follows: In order to perform optical fiber attenuation detection on the optical fiber in the OPLC (9) to be tested, the two ends of one of the optical fibers in the OPLC (9) to be tested are fused with FC / APC single-mode optical fiber jumpers, so that the light generated by the light source (3) is transmitted to the optical power meter (4) through the optical fiber in the OPLC (9) to be tested to measure the magnitude of the optical power; another optical fiber in the OPLC (9) to be tested that is different from the optical fiber connected to the light source (3) and the optical power meter (4) is connected to two connectors of an optical fiber temperature strain analyzer (6) through the FC / APC single-mode optical fiber jumper to form an optical path.

4. The method for synchronously measuring strain and attenuation of optical fiber in OPLC flattening experiment according to claim 3, characterized in that: The specific implementation method of step 3) is as follows: Controlling the magnitude of the current generated by the large current generator (8) for the OPLC (9) to be tested; observing the conductor temperature measured by the thermocouple (1) when the current is stable at a value; when the conductor temperature is stable at a constant value, adjusting the magnitude of the flattening force applied by the pressure test bench (7); recording the magnitude of the optical power measured by the optical power meter (4) under different flattening forces; and measuring the Brillouin frequency of the optical fiber in the OPLC (9) to be tested at this time using the optical fiber temperature strain analyzer (6); The optical power meter (4) collects optical power values ​​at different times and is connected to the optical power recorder (5), and stores the optical power measured each time in the optical power recorder (5); the optical fiber temperature strain analyzer (6) obtains the Brillouin frequencies of the optical fiber at different positions in the OPLC (9) to be tested when the optical path is connected, and the optical fiber temperature strain analyzer (6) contains built-in software for storing the Brillouin frequencies of the optical fiber at different positions in the OPLC (9) to be tested, and the Brillouin frequencies of the optical fiber in the OPLC (9) to be tested measured at different times are stored by the software in the optical fiber temperature strain analyzer (6).

5. The method for synchronously measuring strain and attenuation of optical fiber in OPLC flattening experiment according to claim 4, characterized in that: The specific implementation method of step 4) is as follows: The optical fiber temperature strain analyzer (6) measures the Brillouin frequency of the optical fiber at different positions in the OPLC (9) to be tested after the conductor is stable under different currents. The relationship between the Brillouin frequency and the temperature and strain of the optical fiber at the same time is shown in formula (1): v B (T,ε)=v B (T0,ε0)+C υT (T-T0)+C υε (ε-ε0) (1) where v B (T0,ε0),v B (T, ε) is the Brillouin scattering frequency shift of the optical fiber in the cable measured by the optical fiber temperature strain analyzer when there is no current in the conductor of the OPLC (9) to be tested, the conductor has current and the conductor temperature is stable. ε0, ε are the strain values ​​of the optical fiber in the cable measured when there is no current in the conductor of the OPLC to be tested, the conductor has current and the conductor temperature is stable. T0, T are the temperature values ​​of the optical fiber in the cable measured when there is no current in the conductor of the OPLC to be tested, the conductor has current and the conductor temperature is stable. C vT , C vε are respectively the Brillouin frequency shift temperature coefficient and the Brillouin frequency shift strain coefficient; the Brillouin frequency under different currents and the temperature value measured by the thermocouple (1) are measured by an optical fiber temperature strain analyzer (6), and then the difference between the optical fiber strain when the conductor temperature is stable under the condition of current and the optical fiber strain when there is no current is calculated; The optical fiber attenuation generated during the operation of the OPLC (9) to be tested is obtained from the optical power. When no current passes through the conductor in the OPLC (9) to be tested, an optical power is obtained. When the current passes through the conductor and the conductor temperature is stable, the optical power under this condition can be obtained. Ten times the logarithm of the two optical power values ​​is the optical fiber attenuation of the optical fiber in the OPLC under this current. The relationship between optical power and optical fiber attenuation is shown in formula (2): Wherein P1 is the optical power value measured when there is no current in the conductor of the OPLC (9) to be tested, and P2 is the optical power value measured when there is current in the conductor of the OPLC (9) to be tested and the temperature of the conductor is stable.

6. The method for synchronously measuring strain and attenuation of optical fiber in OPLC flattening experiment according to claim 1, characterized in that: The light source (3) is a monochromatic light source for generating white light with a wavelength of 1550 nm; the optical power meter (4) is a photoelectric detector capable of detecting light with a wavelength range of 185-25000 nm; and the optical fiber temperature strain analyzer (6) is an optical time domain analyzer based on Brillouin scattering, i.e., an optical fiber temperature strain analyzer.

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