OPGW optical fiber polarization detection system and timing method based on handshake timing

Abstract

The present invention relates to an OPGW optical fiber polarization detection system based on handshake timing, comprising a first host and a second host; the first host and the second host are connected through an OPGW and are respectively deployed in different units at both ends of the OPGW. The optical signal handshake timing of the present invention directly multiplexes the OPGW sensing optical fiber, and accurately measures the timing error through the sensing optical handshake at both ends, thereby improving the timing accuracy.

Description

Technical Field

[0001] The invention relates to the field of optical fiber sensing technology, and in particular to an OPGW optical fiber polarization detection system and a timing method based on handshake timing. Background Art

[0002] Optical fiber composite overhead ground wire (OPGW) is a new type of ground wire that has emerged in recent years. It is used as both a lightning protection wire and a communication trunk line. Due to its inherent communication characteristics, lightning strike location can be performed through OPGW itself.

[0003] At present, there are few studies on lightning detection of transmission lines based on OPGW at home and abroad. Japanese scientists have mainly conducted some theoretical research and produced two major technical directions, one is the sensing technology based on Brillouin scattering, and the other is the sensing technology based on the polarization state of light. In the first method, a lightning location system based on Brillouin optical time domain reflectometer was studied, and the lightning location was realized according to the change of OPGW optical signal caused by the temperature rise during lightning strike. However, changes in external temperature and stress will also have a more significant impact on the Brillouin scattering translation effect of the optical signal on OPGW, making the anti-interference ability of this method poor. Therefore, it is still in theoretical research and lacks practical feasibility. The second method is based on the sensing technology of OPGW optical polarization state, which is currently mainly in the theoretical stage and lacks practical demonstration. Starting from the representation and measurement method of optical polarization state, the possibility of realizing lightning location based on OPGW optical polarization state is theoretically introduced, but there is a lack of experimental demonstration. Some scholars have also conducted lightning simulation tests to verify the feasibility of lightning location based on OPGW optical polarization state, but the test type is too single and there is no theoretical analysis.

[0004] In the two-terminal method, if a continuous polarized light signal is applied to the OPGW of the transmission line, and the polarization state of the light signal on the OPGW is detected in real time through photoelectric detection devices at both ends, the lightning strike location of the transmission line can be achieved through the time difference of the polarization state mutation signal obtained at both ends when a lightning strike occurs. However, the two-terminal method generally requires signal collection at both ends, and the collected data needs to be time-aligned. In the traditional two-terminal method, due to the fast speed of light, a time error of 1us corresponds to a spatial positioning error of 100m. Therefore, the construction of the two-terminal method system requires high timing accuracy for the timing system. Summary of the invention

[0005] In view of this, the object of the present invention is to provide an OPGW optical fiber polarization detection system and a timing method based on handshake timing, so as to improve the double-end timing accuracy of double-end lightning polarization detection.

[0006] To achieve the above object, the present invention adopts the following technical solution:

[0007] An OPGW optical fiber polarization detection system based on handshake timing comprises a first host and a second host; the first host and the second host are connected through an OPGW and are respectively deployed in different units at both ends of the OPGW.

[0008] Furthermore, the first host includes a first data storage processing and control unit, a first host computer, a first light source, a first high-speed acquisition card, a first amplifier, a first high-speed detector, a second high-speed detector, a first analyzer, a first coupler and a first wavelength division multiplexing demultiplexer; the first data storage processing and control unit is connected to the first host computer, the first light source and the first high-speed acquisition card respectively; the first light source is connected to the first wavelength division multiplexing demultiplexer through the amplifier; the first high-speed acquisition card is connected to the first high-speed detector and the second high-speed detector respectively; the first high-speed detector is connected to the first wavelength division multiplexing demultiplexer in turn through the first analyzer and the first coupler; the second high-speed detector is connected to the first wavelength division multiplexing demultiplexer through the first coupler.

[0009] Furthermore, the second host includes a second data storage processing and control unit, a second host computer, a second light source, a second high-speed acquisition card, a second amplifier, a third high-speed detector, a fourth high-speed detector, a second analyzer, a second coupler, and a second wavelength division multiplexing demultiplexer; the second data storage processing and control unit is connected to the second host computer, the second light source, and the second high-speed acquisition card respectively; the second light source is connected to the second wavelength division multiplexing demultiplexer through the amplifier; the second high-speed acquisition card is connected to the third high-speed detector and the fourth high-speed detector respectively; the fourth high-speed detector is connected to the second wavelength division multiplexing demultiplexer through the second analyzer and the second coupler in turn; the third high-speed detector is connected to the second wavelength division multiplexing demultiplexer through the second coupler.

[0010] Furthermore, a first pulse modulation module is connected between the first data storage processing and control unit and the first light source.

[0011] Furthermore, a second pulse modulation module is connected between the second data storage processing and control unit and the second light source.

[0012] Furthermore, the second high-speed detection is directly connected to the first pulse modulation module through a circuit lead.

[0013] Furthermore, the four high-speed detectors are directly connected to the second pulse modulation module through circuit leads.

[0014] Furthermore, the first light source and the second light source are both laser light sources.

[0015] Furthermore, the first laser light source emits a DC light signal with a central wavelength λ1, and the second laser light source emits a DC light signal with a central wavelength λ2, and λ1 is not equal to λ2.

[0016] A time synchronization method for an OPGW optical fiber polarization detection system based on handshake time synchronization comprises the following steps:

[0017] Step S1: The first host sends a handshake signal to request time synchronization. At the same time, the first host starts timing, and the second host receives the signal after the time length of teo+L / c+toe.

[0018] Step S2: The second host replies with the same handshake signal and starts timing, and is received by the first host again after teo+L / c+toe time length;

[0019] Step S3: The first host timing is tA=2*(teo+L / c+toe), the second host timing is tB=teo+L / c+toe, the time difference between the first host and the second host is Δt=tA / 2, then Δt=tB completes the timing;

[0020] Where: teo is the electro-optical conversion delay, toe is the photoelectric conversion delay, L is the optical fiber length, and c is the speed of light.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The present invention uses a splitter device to multiplex the OPGW optical fiber polarization sensing optical path to reduce the construction cost of the timing module. Compared with other timing modules, the optical signal handshake timing of this method directly multiplexes the OPGW sensing optical fiber, and accurately measures the timing error (time difference) through the sensing optical handshake at both ends, thereby improving the timing accuracy.

[0023] 2. The present invention adopts a pulse modulation module and a DC light source, which not only meets the DC light requirements of lightning detection, but also meets the pulse light requirements of the optical timing system. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a system framework diagram of the present invention;

[0025] Figure 2 It is an optical handshake timing subsystem in a system in one embodiment of the present invention, which is composed of a timing unit, a laser, a detector, and a wavelength division multiplexer at each end. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0027] Please refer to Figure 1The present invention provides an OPGW optical fiber polarization detection system based on handshake timing, including a first host and a second host; the first host and the second host are connected through OPGW and are respectively deployed in different units at both ends of OPGW. The first host includes a first data storage processing and control unit, a first host computer, a first light source, a first high-speed acquisition card, a first amplifier, a first high-speed detector, a second high-speed detector, a first analyzer, a first coupler and a first wavelength division multiplexing demultiplexer; the first data storage processing and control unit is respectively connected to the first host computer, the first light source and the first high-speed acquisition card; the first light source is connected to the first wavelength division multiplexing demultiplexer through the amplifier; the first high-speed acquisition card is respectively connected to the first high-speed detector and the second high-speed detector; the first high-speed detector is sequentially connected to the first wavelength division multiplexing demultiplexer through the first analyzer and the first coupler; the second high-speed detector is connected to the first wavelength division multiplexing demultiplexer through the first coupler. The second host includes a second data storage processing and control unit, a second host computer, a second light source, a second high-speed acquisition card, a second amplifier, a third high-speed detector, a fourth high-speed detector, a second analyzer, a second coupler, and a second wavelength division multiplexing demultiplexer; the second data storage processing and control unit is connected to the second host computer, the second light source, and the second high-speed acquisition card respectively; the second light source is connected to the second wavelength division multiplexing demultiplexer through the amplifier; the second high-speed acquisition card is connected to the third high-speed detector and the fourth high-speed detector respectively; the fourth high-speed detector is connected to the second wavelength division multiplexing demultiplexer through the second analyzer and the second coupler in turn; the third high-speed detector is connected to the second wavelength division multiplexing demultiplexer through the second coupler.

[0028] Preferably, in this embodiment, a pulse modulation module is further connected between the data storage processing and control unit and the light source, for switching between pulse light signals and DC light signals under the control of the data storage processing and control unit.

[0029] Preferably, in this embodiment, the second high-speed detector and the fourth high-speed detector can also be directly connected to the pulse modulation modules of their respective hosts through circuit leads, so as to directly trigger the pulse modulation circuit to send a narrow pulse signal to reply to the other end during the synchronization stage.

[0030] Preferably, in this embodiment, the first light source and the second light source are both laser light sources. The first laser light source emits a DC light signal with a central wavelength λ1, and the second laser light source emits a DC light signal with a central wavelength λ2, and λ1 and λ2 are not equal.

[0031] Preferably, in this embodiment, the splitting ratio of the first coupler and the second coupler is 10 to 90, of which 10 percent is given to the second high-speed detector and the fourth high-speed detector for time synchronization; and 90 percent is given to the first polarizer and the second polarizer for optical fiber polarization sensing of lightning.

[0032] In this embodiment, a timing method of an OPGW optical fiber polarization detection system based on handshake timing is also provided, comprising the following steps:

[0033] Step S1: The first host sends a handshake signal to request time synchronization. At the same time, the first host starts timing, and the second host receives the signal after the time length of teo+L / c+toe.

[0034] Step S2: The second host replies with the same handshake signal and starts timing, and is received by the first host again after teo+L / c+toe time length;

[0035] Step S3: The first host timing is tA=2*(teo+L / c+toe), the second host timing is tB=teo+L / c+toe, the time difference between the first host and the second host is Δt=tA / 2, then Δt=tB completes the timing;

[0036] Where: teo is the electro-optical conversion delay, toe is the photoelectric conversion delay, L is the optical fiber length, and c is the speed of light.

[0037] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention should fall within the scope of the present invention.

Claims

1. An OPGW optical fiber polarization detection system based on handshake timing, characterized in that: It includes a first host and a second host; the first host and the second host are connected through an OPGW and are respectively deployed in different units at both ends of the OPGW; The first host includes a first data storage processing and control unit, a first host computer, a first light source, a first high-speed acquisition card, a first amplifier, a first high-speed detector, a second high-speed detector, a first analyzer, a first coupler and a first wavelength division multiplexing demultiplexer; the first data storage processing and control unit is connected to the first host computer, the first light source and the first high-speed acquisition card respectively; the first light source is connected to the first wavelength division multiplexing demultiplexer through the amplifier; the first high-speed acquisition card is connected to the first high-speed detector and the second high-speed detector respectively; the first high-speed detector is connected to the first wavelength division multiplexing demultiplexer through the first analyzer and the first coupler in sequence; the second high-speed detector is connected to the first wavelength division multiplexing demultiplexer through the first coupler; The second host includes a second data storage processing and control unit, a second host computer, a second light source, a second high-speed acquisition card, a second amplifier, a third high-speed detector, a fourth high-speed detector, a second analyzer, a second coupler, and a second wavelength division multiplexing demultiplexer; the second data storage processing and control unit is connected to the second host computer, the second light source, and the second high-speed acquisition card respectively; the second light source is connected to the second wavelength division multiplexing demultiplexer through the amplifier; the second high-speed acquisition card is connected to the third high-speed detector and the fourth high-speed detector respectively; the fourth high-speed detector is connected to the second wavelength division multiplexing demultiplexer through the second analyzer and the second coupler in sequence; the third high-speed detector is connected to the second wavelength division multiplexing demultiplexer through the second coupler; The splitting ratio of the first coupler and the second coupler is 10:90, of which 10% is given to the second high-speed detector and the third high-speed detector for time synchronization; and 90% is given to the first polarization analyzer and the second polarization analyzer for optical fiber polarization sensing of lightning; A first pulse modulation module is also connected between the first data storage processing and control unit and the first light source; A second pulse modulation module is also connected between the second data storage processing and control unit and the second light source; The time synchronization method of the system comprises the following steps: Step S1: The first host sends a handshake signal to request time synchronization. At the same time, the first host starts timing, and the second host receives the signal after the time length of teo+L / c+toe. Step S2: The second host replies with the same handshake signal and starts timing, and is received by the first host again after teo+L / c+toe time length; Step S3: The first host timing is tA=2*(teo+L / c+toe), the second host timing is tB=teo+L / c+toe, the time difference between the first host and the second host is Δt=tA / 2, then Δt=tB completes the timing; Where: teo is the electro-optical conversion delay, toe is the photoelectric conversion delay, L is the optical fiber length, and c is the speed of light.

2. The OPGW optical fiber polarization detection system based on handshake timing according to claim 1 is characterized in that: The second high-speed detection is directly connected to the first pulse modulation module through a circuit lead.

3. The OPGW optical fiber polarization detection system based on handshake timing according to claim 1 is characterized in that: The four high-speed detectors are directly connected to the second pulse modulation module through circuit leads.

4. The OPGW optical fiber polarization detection system based on handshake timing according to claim 1 is characterized in that: The first light source and the second light source are both laser light sources.

5. The OPGW optical fiber polarization detection system based on handshake timing according to claim 4 is characterized in that: The first laser light source emits a direct current light signal with a central wavelength λ1, and the second laser light source emits a direct current light signal with a central wavelength λ2, and λ1 is not equal to λ2.

Images