CN103760474A - OPGW optical cable stress testing method - Google Patents

Abstract

The present invention relates to an OPGW optical cable stress test method, which is characterized in that it includes the following steps: Step S01: Screening OPGW lines; the screening basis is: high-level lines must be selected; lines with accident history are preferred; accident hidden dangers line considerations; Step S02: Use fiber optic strain analyzer AQ8603 to collect and analyze the Brillouin spectrum of the optical fiber; Step S03: Use BOTDR and OTDR instruments to test the stress and attenuation of the optical fiber cable from south to north for the OPGW composite optical cable of the backbone network ; and analyze the OPGW composite optical cable from the test data and the data collected in step S02 to locate the fault. The invention can ensure that the staff can timely discover the potential hidden troubles of the OPGW optical cable, distinguish the types of the troubles and deal with the hidden troubles.

Description

OPGW Optical Cable Stress Test Method

technical field

The invention relates to an OPGW optical cable stress test method.

Background technique

Optical cable communication has grown stronger with the development of the Fujian electric power system, but the application of optical fiber Brillouin scattering technology has remained in OPGW optical cable manufacturers for a long time. OPGW optical cable test database. In particular, there is a lack of OPGW optical fiber strain database dedicated to the climate characteristics and line characteristics in Fujian. It is impossible to compare the changes in the stress of OPGW optical cables that have been running for a long time. Improve the level of OPGW optical cable safety operation management. OPGW optical cable, Optical FiberComposite Overhead Ground Wire (also known as optical fiber composite overhead ground wire).

Contents of the invention

The purpose of the present invention is to provide a kind of OPGW optical cable stress test method, not only can realize the fault of backbone network OPGW composite optical cable by this method, but also can build backbone network OPGW composite optical cable basic database according to the data collected.

The present invention adopts following scheme to realize: a kind of OPGW optical cable stress testing method is characterized in that comprising the following steps:

Step S01: Screen the OPGW lines; the screening basis is: high-level lines must be selected; lines with accident history are preferred; lines with potential accidents are considered;

Step S02: At one end of the optical fiber, the BOTDR continuously injects pulsed light of different frequencies into the optical fiber, and receives the Brillouin backscattered light at the same end, and uses the optical fiber strain analyzer AQ8603 to collect and analyze the Brillouin spectrum of the optical fiber. analyze;

Step S03: Use BOTDR and OTDR instruments to test the stress and attenuation of the OPGW composite optical cable of the backbone network from south to north; and analyze the OPGW composite optical cable from the test data and the data collected in step S02 to locate the fault.

In an embodiment of the present invention, the Anritsu MX90 series OTDR is used to test the line attenuation before the step S02.

In one embodiment of the present invention, the test method and the fiber core selection during the test in the step S03 are as follows: for a line longer than a predetermined value, the two-end test method is adopted, that is, the line state is analyzed by testing from both ends of the line ; For general lines, if the single-ended test can detect the length of the line, only single-ended test is performed;

The line includes two types of optical fibers, G652 and G655. When selecting optical fibers, one core is required for each; if the line contains multiple tube bundles, one core needs to be tested in each tube bundle.

The application of the present invention can prevent hidden dangers from turning into faults, can implement active monitoring for electric power monitoring, discover potential hidden troubles in time, identify fault types and deal with hidden dangers.

Description of drawings

Fig. 1 is a schematic flow chart of the present invention.

Figure 2 shows the BOTDR test data of 500kV Sanyang Substation-500kV Chentian Substation, the horizontal axis is the distance, and the vertical axis is the calculated strain of the optical fiber.

Figure 3 is a schematic diagram of the strain test.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

As shown in Figure 1, the present embodiment provides a kind of OPGW optical cable stress test method, it is characterized in that comprising the following steps:

Step S01: Screen the OPGW lines; the screening basis is: high-level lines must be selected; lines with accident history are preferred; lines with potential accidents are considered;

Step S02: At one end of the optical fiber, the BOTDR continuously injects pulsed light of different frequencies into the optical fiber, and receives the Brillouin backscattered light at the same end, and uses the optical fiber strain analyzer AQ8603 to collect and analyze the Brillouin spectrum of the optical fiber. analyze;

Step S03: Use BOTDR and OTDR instruments to test the stress and attenuation of the OPGW composite optical cable of the backbone network from south to north; and analyze the OPGW composite optical cable from the test data and the data collected in step S02 to locate the fault.

The distributed optical fiber sensing technology includes three kinds of scattered light spectrum analysis techniques: Rayleigh scattering, Brillouin scattering and Raman scattering. Among them, the basic principle of Brillouin scattering is to use the linear relationship between the drift of the central frequency of the Brillouin scattering spectrum on a single section of the fiber and the axial strain and temperature of the fiber. A technique for measuring axial strain by analyzing center frequency drift. In the invention, at one end of the optical fiber, the BOTDR continuously injects pulsed light of different frequencies into the optical fiber, and receives Brillouin backscattered light at the same end. Please refer to Figure 2 and Figure 3, Brillouin scattered light spectrum can be obtained by using BOTDR technology and Brillouin spectroscopic technology. The frequency corresponding to the peak on the spectrum is the frequency of Brillouin scattered light, and the distribution of axial strain along the fiber can be calculated. Based on the above-mentioned distributed Brillouin optical fiber sensing technology, the geographical environment, meteorological information and other conditions were analyzed for the distribution of OPGW composite optical cables in a backbone network. The following research contents can be determined and the basic database of OPGW composite optical cables in the backbone network can be established:

1. Basic data under the influence of harsh operating conditions on OPGW composite optical cables. A power transmission line often has to pass through different meteorological regions, the geography and environment are complex, and even pass through no-man's land. The distance between communication stations is also long, which brings difficulties to the setup and operation of relay stations. There are many large spans and high hanging points, and the problem of wind-induced vibration is serious.

2. Lightning strikes have a serious impact on OPGW composite optical cables. From the analysis of the lightning strike mechanism, the transmission line with high voltage level is easy to be struck by lightning, and the lightning current energy is also large. The operating experience of high-voltage lines in various countries shows that although their insulation level is very high, it is still impossible to completely withstand lightning, and the actual lightning trip rate is often much higher than the design value, especially the level of lightning shielding. The larger the proportion of the total trip times.

3. Basic data under the influence of high mechanical performance requirements on OPGW composite optical cables. Large cross-section and large span lead to heavy weight per unit length, special structure, and large comprehensive load. In order to meet the needs of long-term safe operation, the armor protection of the optical unit must be better, the safety factor must be large, and the performance requirements for supporting fittings are also high. .

4. The impact of high electrical performance requirements on OPGW composite optical cables. Due to the high rated voltage of the system and the long transmission line, the submerged power supply arc is not easy to be extinguished quickly, so the reclosing cannot be completed quickly, and the power supply reliability is difficult to meet the requirements. In the high-voltage power grid, the use of a good conductor ground wire can significantly reduce the mutual inductance coupling component, which is conducive to reducing the potential supply current and power frequency overvoltage. The control of the temperature rise of metal wires and the release of lightning charges all require better electrical performance. For parallel double-circuit lines, due to the requirements of the system, when one of the lines fails or is overhauled, there is an operation mode of short-term over-capacity transmission of the other line.

It is worth mentioning that the technical parameters of the test equipment of the present invention are shown in Table 1. In this embodiment, the above-mentioned optical fiber strain analyzer AQ8603 is used, which uses the self-published Brillouin backscattered light detection technology to perform Brillouin analysis on the optical fiber. Spectrum acquisition and analysis.

Measuring distance 1, 2, 5, 10, 20, 40, 80km sampling interval Minimum 5cm distance resolution Minimum 1m Sampling point Maximum 20000 Strain range -6%～6% Strain resolution 1με Test frequency range 9.9-11.9GHz Test wavelength 1550nm Test frequency interval 1, 2, 5, 10, 20, 50MHz Average times 2 ¹⁰ -2 ²⁴ Strain Test Accuracy ±0.003% repeatability <0.02% Various analysis functions Strain distribution, Brillouin spectral distribution, line attenuation

Table I

At present, OPGW line failures mainly include icing, lightning strikes, tower collapse, and wind dance. Theoretical analysis shows that before icing, lightning strikes and tower collapse accidents, there will be large strain changes in OPGW lines. According to the characteristics of the three, therefore, the present invention first screens the OPGW lines. The screening basis is: high-grade lines must be selected; lines with accident history are preferred; lines with potential accidents are considered.

According to the above method, the main content of the basic data collection work in [Phase I] is 20 500kVO PGW optical cable lines, and data collection is also carried out on 6 220kV OPGW optical cable lines. See the table below for specific lines. [Phase II] The data collection line is the same as that of [Phase I].

Note: B1 and B4 in the table represent fiber types, representing G652 and G655 fibers respectively.

It is worth noting that the test method and fiber core selection steps of the present invention are as follows:

For longer lines, use the two-end test method, that is, test the line from both ends to analyze the line status. For general lines, if the single-ended test can detect the length of the line, only the single-ended test is performed.

Because the line includes two types of optical fibers, G652 and G655, you need to select one core for each optical fiber. If the circuit contains multiple tube bundles, one core needs to be tested in each tube bundle.

Considering the type of fiber, the number of tube bundles and the test conditions of [Phase 1], the fiber cores selected for line collection of [Phase 2] are as follows (arranged in order of data collection time).

Before testing strain with AQ8603, the present invention uses Anritsu MX90 series OTDR to test line attenuation. AQ8603 sampling data results are related to the 0 strain frequency in the equipment, because different 0 strain frequencies may cause the overall translation (up or down) of the two strain data of the same line. In this case, the change in data value is not due to a change in the line body, and the problem is automatically ignored in the analysis.

The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope of the present invention.

Claims (3)

1. A kind of OPGW optical cable stress testing method is characterized in that comprising the following steps: Step S01: Screen the OPGW lines; the screening basis is: high-level lines must be selected; lines with accident history are preferred; lines with potential accidents are considered; Step S02: At one end of the optical fiber, the BOTDR continuously injects pulsed light of different frequencies into the optical fiber, and receives the Brillouin backscattered light at the same end, and uses the optical fiber strain analyzer AQ8603 to collect and analyze the Brillouin spectrum of the optical fiber. analyze; Step S03: Use BOTDR and OTDR instruments to test the stress and attenuation of the OPGW composite optical cable of the backbone network from south to north; and analyze the OPGW composite optical cable from the test data and the data collected in step S02 to locate the fault. 2. The OPGW optical cable stress test method according to claim 1, characterized in that: Anritsu MX90 series OTDR is used to test the line attenuation before the step S02. 3. OPGW optical cable stress testing method according to claim 1, is characterized in that: the testing method in the described step S03 and the fiber core selection during testing are as follows: For the line longer than a predetermined value, adopt the two-end test method, that is, test the line status from both ends of the line separately; for general lines, if the single-ended test can detect the line length, only the single-ended test is performed; The line includes two types of optical fibers, G652 and G655. When selecting optical fibers, one core is required for each; if the line contains multiple tube bundles, one core needs to be tested in each tube bundle.

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