Hydropower station optical cable safe operation monitoring device and monitoring system

Abstract

The utility model provides a hydropower station optical cable safe operation monitoring device and monitoring system, and the hydropower station optical cable safe operation monitoring device comprises a pulsed light unit, a circulator, a reflector, a detector, an acquisition card, and a second coupler. The reflector is used for being connected with a second port of the to-be-monitored hydroelectric optical cable, and is used for reflecting pulsed light at the tail of the hydroelectric optical cable and Rayleigh scattering light generated by the to-be-monitored hydroelectric optical cable back to the to-be-monitored hydroelectric optical cable, and the pulsed light and the Rayleigh scattering light reach the second coupler through the second port and the third port of the circulator; and the output end of the second coupler is also connected with the input end of the detector and is used for carrying out interference on the light entering the second coupler to generate an interference light signal. The hydroelectric optical cable Rayleigh scattering light which goes back and forth twice can be measured at the detector by utilizing the reflection of the reflecting mirror, and the detection noise can be reduced by averaging the two results, so that the signal ratio of signals is improved, and the vibration detection sensitivity is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of hydropower station monitoring, and particularly relates to a monitoring device and a monitoring system for the safe operation of optical cables in hydropower stations. Background Technique

[0002] The optical cable of a hydropower station is the basis of the communication system of the hydropower station. If the optical cable is damaged or destroyed, it will seriously affect the operation of the hydropower station. Due to the special operating environment where the optical cable of the hydropower station is located, it is vulnerable to the threat of intrusion and damage by humans and animals. For this intrusion monitoring requirement, a phase optical time domain reflectometer is usually used to monitor the vibration along the optical fiber at present. However, the phase optical time domain reflectometer detects Rayleigh scattered light, and the Rayleigh scattered light is only one-thousandth of the incident pulse light power, and the signal-to-noise ratio of the signal is relatively low. Therefore, the sensitivity of the system is limited, and generally, it can only sense the intrusion vibration within a few meters near the optical fiber.

[0003] In view of this, overcoming the defects of the existing technology is an urgent problem to be solved in this technical field. Content of the Utility Model

[0004] In view of the above problems, it is necessary to propose a monitoring device for the safe operation of optical cables in hydropower stations to solve or partially solve the above problems, thereby reducing detection noise, improving the signal ratio of monitoring signals, and improving the vibration detection sensitivity. The technical solution proposed by the utility model is as follows:

[0005] In a first aspect, the utility model proposes a monitoring device for the safe operation of optical cables in hydropower stations, including a pulsed light unit 10, a circulator 20, a reflector 30, a detector 40, a data acquisition card 50, and a second coupler 70, wherein:

[0006] The pulsed light unit 10 includes a laser 11, a semiconductor amplifier 12, a pulsed signal source 13, and a first coupler 14. The input end of the first coupler 14 is connected to the laser 11, the first output end of the first coupler 14 is connected to the first input end of the semiconductor amplifier 12, and the second output end of the first coupler 14 is connected to the first input end of the second coupler 70;

[0007] The second input end of the semiconductor amplifier 12 is connected to the pulsed signal source 13, and the output end is connected to the circulator 20;

[0008] The circulator 20 includes three ports. The first port is connected to the output port of the pulsed light unit 10, the second port is connected to the first port of the optical cable of the hydropower station to be monitored, and the third port is connected to the second end of the second coupler 70;

[0009] The mirror 30 is used to connect to the second port of the hydroelectric optical cable to be monitored, and is configured to reflect the pulsed light at the end of the hydroelectric optical cable and the Rayleigh scattered light generated by the hydroelectric optical cable to be monitored back into the hydroelectric optical cable to be monitored, and reach the second coupler 70 through the second port and the third port of the circulator 20;

[0010] The output end of the second coupler 70 is also connected to the input end of the detector 40, and is configured to interfere with the light entering the second coupler 70 to generate an interference optical signal;

[0011] The output end of the detector 40 is also connected to the acquisition card 50, and is configured to convert the interference optical signal output by the second coupler 70 into an electrical signal and send it to the acquisition card 50;

[0012] The output end of the acquisition card 50 is used to connect to an external controller 80, and is configured to convert the electrical signal transmitted by the detector 40 into a digital signal and send it to the external controller 80 for analysis and processing.

[0013] Preferably, an erbium-doped fiber amplifier 60 is further included. The input end of the erbium-doped fiber amplifier 60 is connected to the output end of the semiconductor amplifier 12, and the output end of the erbium-doped fiber amplifier 60 is connected to the first port of the circulator 20.

[0014] Preferably, the splitting ratio of the first coupler 14 is 9:1.

[0015] Preferably, the splitting ratio of the second coupler 70 is 1:1.

[0016] Preferably, the bandwidth of the detector 40 is greater than 250 MHz.

[0017] Preferably, the laser 11 operates at a wavelength of 1550 nm.

[0018] In a second aspect, the present invention provides a monitoring system for the safe operation of a hydroelectric power station optical cable, including the monitoring device for the safe operation of a hydroelectric power station optical cable as described in the first aspect and a controller 80 connected to the acquisition card 50.

[0019] Preferably, the controller 80 is further connected to the erbium-doped fiber amplifier 60 and is configured to adjust the current of the erbium-doped fiber amplifier 60.

[0020] Based on the above technical solutions, the beneficial effects of the present invention compared with the prior art are:

[0021] The present utility model provides a monitoring device for the safe operation of an optical cable in a hydropower station, which includes a pulsed light unit 10, a circulator 20, a reflector 30, a detector 40, and a data acquisition card 50, where: The pulsed light unit 10 includes a laser 11, a semiconductor amplifier 12, a pulsed signal source 13, and a first coupler 14. The input end of the first coupler 14 is connected to the laser 11, the first output end of the first coupler 14 is connected to the first input end of the semiconductor amplifier 12, and the second output end of the first coupler 14 is connected to the first input end of the second coupler 70; The circulator 20 includes three ports. The first port is connected to the output port of the pulsed light unit 10, the second port is connected to the first port of the optical cable to be monitored in the hydropower station, and the third port is connected to the input end of the detector 40. The reflector 30 is used to be connected to the second port of the optical cable to be monitored in the hydropower station, and is used to reflect the pulsed light at the end of the optical cable in the hydropower station and the Rayleigh scattered light generated by the optical cable to be monitored back into the optical cable to be monitored, and reach the second coupler 70 through the second port and the third port of the circulator 20; The output end of the second coupler 70 is also connected to the input end of the detector 40, and is used to interfere with the light entering the second coupler 70 (pulsed light, reflected Rayleigh scattered light, and the light source laser separated by the first coupler 14) to generate an interference light signal. The detector 40 converts the interference light signal into an electrical signal, and the data acquisition card 50 acquires the electrical signal and transmits it to a computer for signal analysis.

[0022] Compared with a general phase optical time domain reflectometer, in this embodiment, the reflection of the reflector 30 is used to measure the Rayleigh scattered light of the optical cable in the hydropower station that contains two round trips at the detector 40. By averaging the two results, the detection noise can be reduced, thereby improving the signal-to-noise ratio of the signal and enhancing the vibration detection sensitivity. This embodiment also additionally detects the signal of the emitted pulsed light after passing through the optical cable in the hydropower station. Since the power of the pulsed light is several times that of the Rayleigh scattered light, the vibration situation around the optical cable can be more sensitively sensed. In addition, this embodiment collects the interference light generated by the pulsed light, Rayleigh scattered light, and light source laser, realizing coherent detection. Coherent detection can improve the optical power compared with direct detection, thereby improving the signal-to-noise ratio. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following will briefly introduce the drawings required to be used in the embodiments of the present utility model. Obviously, the following described drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0024] Figure 1 It is a schematic structural diagram of a monitoring device for the safe operation of an optical cable in a hydropower station in an embodiment of the present utility model;

[0025] Figure 2 This is a schematic structural diagram of a monitoring system for the safe operation of optical cables in a hydropower station in an embodiment of the present utility model. Specific embodiments

[0026] In order to make the objectives, technical solutions and advantages of the present utility model more clear and understandable, the present utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0027] Unless otherwise required by the context, throughout the specification and claims, the term "comprising" is interpreted in an open, inclusive sense, i.e., "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "examples", "specific examples" or "some examples", etc., are intended to indicate that specific features, structures, materials or characteristics related to the embodiment or example are included in at least one embodiment or example of the present disclosure. The schematic representations of the above terms are not necessarily directed to the same embodiment or example. In addition, the specific features, structures, materials or characteristics may be included in any one or more embodiments or examples in any appropriate manner, that is, although they may be carried in the embodiments or examples of the above terms due to reasons such as the order and position of appearance, they are not limited to being carried in a combined manner by one embodiment or example.

[0028] In the description of the present utility model, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the embodiments of the present disclosure, unless otherwise stated, the meaning of "a plurality" is two or more. In addition, for example, in the description, for the same type of nouns, the method of adding "A" and "B" at the end is used to describe them as two independent individuals. In this case, the features defined with "A" and "B" are only used for the purpose of distinguishing similar individuals and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features.

[0029] Embodiment 1:

[0030] In some embodiments, the present utility model proposes a monitoring device for the safe operation of optical cables in a hydropower station. As shown in combination with Figure 1 , it includes a pulsed light unit 10, a circulator 20, a mirror 30, a detector 40, a capture card 50, and a second coupler 70, where:

[0031] The pulsed light unit 10 includes a laser 11, a semiconductor amplifier 12, a pulsed signal source 13, and a first coupler 14. Among them, the input end of the first coupler 14 is connected to the laser 11, the first output end of the first coupler 14 is connected to the first input end of the semiconductor amplifier 12, and the second output end of the first coupler 14 is connected to the first input end of the second coupler 70. The second input end of the semiconductor amplifier 12 is connected to the pulsed signal source 13, and the output end of the semiconductor amplifier 12 is connected to the circulator 20 (as Figure 1 shown).

[0032] The circulator 20 includes three ports. The first port a is connected to the output port of the pulsed light unit 10, the second port b is connected to the first port of the hydropower optical cable to be monitored, and the third port c is connected to the input end of the detector 40.

[0033] The mirror 30 is used to be connected to the second port of the hydropower optical cable to be monitored, and is used to reflect the pulsed light at the end of the hydropower optical cable and the Rayleigh scattered light generated by the hydropower optical cable to be monitored back into the hydropower optical cable to be monitored.

[0034] The second input end of the second coupler 70 is further connected to the third port of the circulator 20, the output end of the second coupler 70 is further connected to the input end of the detector 40, and the second coupler 70 is used to interfere the pulsed light output from the third port of the circulator 20 and the Rayleigh scattered light with the light source laser output from the first coupler 14 to generate an interference light signal.

[0035] The output end of the detector 40 is further connected to the acquisition card 50, and is used to convert the interference light output from the second coupler 70 into an electrical signal and send it to the acquisition card 50. The output end of the acquisition card 50 is used to be connected to an external controller, and is used to convert the electrical signal transmitted from the detector 40 into a digital signal and send it to the external controller for analysis and processing.

[0036] The output end of the acquisition card 50 is used to be connected to an external controller, and is used to convert the electrical signal transmitted from the detector 40 into a digital signal and send it to the external controller for analysis and processing. It can be understood that according to the principle of the existing phase optical time domain reflectometer, the external processor will record the waveforms of the pulsed light and the Rayleigh scattered light. When their waveforms change significantly, it indicates that the optical fiber has deformed, that is, there is an intrusion event around the optical fiber.

[0037] Preferably, in some embodiments, the monitoring device for the safe operation of the optical cable of the hydropower station further includes an erbium-doped fiber amplifier 60. The input end of the erbium-doped fiber amplifier 60 is connected to the pulsed light unit 10, and the output end of the erbium-doped fiber amplifier 60 is connected to the first port of the circulator 20. That is, the pulsed light output by the pulsed light unit 10 is amplified by the erbium-doped fiber amplifier 60 and then enters the circulator 20. When the pulsed light travels from the second port b of the circulator 20 to the mirror 30 (forward) and from the mirror 30 to the second port b (backward), backward Rayleigh scattered light is generated by the interaction with the optical fiber. The forward light is relatively strong, and even without using the erbium-doped fiber amplifier 60, the detector can detect the forward scattered light. However, the backward scattered light is relatively weak. If the erbium-doped fiber amplifier 60 is not used, the backward scattered light may be submerged by noise, and there may be a situation where the detector 40 cannot detect it.

[0038] In some embodiments, the laser 11 emits direct current laser light with a working wavelength near 1550 nm and a line width less than 100 kHz. The splitting ratio of the first coupler 14 is 9:1, and the splitting ratio of the second coupler 70 is 1:1. The bandwidth of the detector 40 is greater than 250 MHz. The mirror 30 can reflect the incident light back into the optical fiber with a reflectivity greater than 99%. The sampling rate of the acquisition card 50 is greater than 500 MSa / s.

[0039] Taking the optical fiber as the medium, the light emitted by the laser 11 passes through the first coupler 14. 90% of the light is modulated into pulsed light by the semiconductor optical amplifier 12 and the pulsed signal source 13. After passing through the erbium-doped fiber amplifier 60, the pulsed light enters the hydropower optical cable to be measured through the first port a of the circulator 20 and enters the second port b. The pulsed light is reflected by the mirror 30 at the end of the hydropower optical cable and re-enters the hydropower optical cable, and reaches the second coupler 70 from the third port c of the circulator 20. When the pulsed light travels from the second port b of the circulator 20 to the mirror 30 (forward) and from the mirror 30 to the second port b (backward), backward Rayleigh scattered light is generated by the interaction with the optical fiber. Among them, the Rayleigh scattered light generated during the backward process is reflected by the mirror 30 and re-enters the hydropower optical cable. The forward and backward Rayleigh scattered light returns through the second port b of the circulator 20 and enters the coupler 2 from the third port c. Finally, the pulsed light and the Rayleigh scattered light interfere with the 10% light source laser in the first coupler 14 at the second coupler 70, and the detector 40 converts the interference light signal into an electrical signal. The acquisition card 50 acquires this electrical signal and transmits it to the controller or computer for signal analysis. After coherent detection, the intensity of the signal is related to the phase of the light. Only the forward scattered light can respond to the external environment, and the external processor can discover the waveform changes of the pulsed light and the Rayleigh scattered light to judge the existence of intrusion events around the hydropower optical cable to be measured.

[0040] Compared with a general phase optical time domain reflectometer, the measurement results of this embodiment include the Rayleigh scattered light of the hydroelectric optical cable for two round trips. By averaging the two results, the detection noise can be reduced, thereby improving the signal-to-signal ratio of the signal and enhancing the vibration detection sensitivity. In addition, this embodiment also additionally detects the signal of the emitted pulsed light after passing through the hydroelectric optical cable. Since the power of the pulsed light is more than 1000 times that of the Rayleigh scattered light, the vibration situation around the optical cable can be sensed more sensitively. In addition, this embodiment collects the interference light generated by the pulsed light, Rayleigh scattered light, and source laser, realizes coherent detection, and the coherent detection can improve the optical power compared with direct detection, thereby improving the signal-to-noise ratio.

[0041] Embodiment 2:

[0042] The present utility model also discloses a monitoring system for the safe operation of a hydroelectric power station optical cable, as Figure 2 shown, including a pulsed light unit 10, a circulator 20, a reflector 30, a detector 40, a data acquisition card 50, an erbium-doped fiber amplifier 60, a second coupler 70, and a controller 80, wherein:

[0043] The pulsed light unit 10 includes a laser 11, a semiconductor amplifier 12, a pulsed signal source 13, and a first coupler 14. Among them, the input end of the first coupler 14 is connected to the laser 11, the first output end of the first coupler 14 is connected to the first input end of the semiconductor amplifier 12, and the second output end of the first coupler 14 is connected to the first input end of the second coupler 70. The second input end of the semiconductor amplifier 12 is connected to the pulsed signal source 13, and the output end of the semiconductor amplifier 12 is connected to the input end of the erbium-doped fiber amplifier 60.

[0044] The circulator 20 includes three ports. The first port a is connected to the output end of the erbium-doped fiber amplifier 60, the second port b is connected to the first port of the hydroelectric optical cable to be monitored, and the third port c is connected to the input end of the detector 40.

[0045] The reflector 30 is used to be connected to the second port of the hydroelectric optical cable to be monitored, and is used to reflect the pulsed light at the end of the hydroelectric optical cable and the Rayleigh scattered light generated by the hydroelectric optical cable to be monitored back into the hydroelectric optical cable to be monitored.

[0046] The second input end of the second coupler 70 is also connected to the third port of the circulator 20, and the output end of the second coupler 70 is also connected to the input end of the detector 40. The second coupler 70 is used to make the pulsed light and Rayleigh scattered light output from the third port of the circulator 20 interfere with the source laser output from the first coupler 14 to generate an interference light signal.

[0047] The output end of the detector 40 is also connected to the acquisition card 50, and is used to convert the interference light output by the second coupler 70 into an electrical signal and send it to the acquisition card 50. The output end of the acquisition card 50 is used to connect to an external controller, and is used to convert the electrical signal transmitted from the detector 40 into a digital signal and send it to the external controller for analysis and processing.

[0048] The output end of the acquisition card 50 is used to connect to an external controller, and is used to convert the electrical signal transmitted from the detector 40 into a digital signal and send it to the external controller for analysis and processing.

[0049] The controller 80 is used to record the waveforms of the pulsed light and the Rayleigh scattered light. When their waveforms change significantly, it indicates that the optical fiber has deformed, that is, there is an intrusion event around the optical fiber.

[0050] In some embodiments, the controller 80 is connected to the erbium-doped fiber amplifier 60 and is used to adjust the current of the erbium-doped fiber amplifier 60.

[0051] During the process of the pulsed light from the second port b of the circulator 20 to the mirror 30 (forward) and from the mirror 30 to the second port b (backward), backward Rayleigh scattered light is generated by the interaction with the optical fiber. The forward Rayleigh scattered light is relatively strong, and even without using the erbium-doped fiber amplifier 60, the detector can detect the forward scattered light; however, the backward scattered light is relatively weak. If the erbium-doped fiber amplifier 60 is not used, the backward scattered light may be submerged by noise, and there is a situation where the detector 40 cannot detect it.

[0052] In practical applications, due to the large power of the pulsed light, even if the erbium-doped fiber amplifier 60 does not work, the detector 40 can detect the signal. Therefore, during normal operation, the controller 80 can be used to control the erbium-doped fiber amplifier 60 to work in a low-current state first, and only the intensity change of the pulsed light after coherent detection needs to be monitored. When the pulsed light changes, it indicates that there is a potential intrusion event around the optical cable. At this time, the controller 80 controls the current of the erbium-doped fiber amplifier 60 to be adjusted to the maximum. Based on the existing OTDR principle, distributed measurement is carried out using the Rayleigh scattered light output by the detector to achieve vibration positioning. The utility model utilizes the hydroelectric power station optical cable safety operation monitoring device of Embodiment 1. By using the reflection of the mirror, the Rayleigh scattered light of the hydroelectric power cable including two round trips can be measured at the detector. By averaging the two results, the detection noise can be reduced, thereby improving the signal-to-noise ratio of the signal and enhancing the vibration detection sensitivity. This embodiment also additionally detects the signal after the emitted pulsed light passes through the hydroelectric power cable. Since the power of the pulsed light is several times that of the Rayleigh scattered light, the vibration situation around the optical cable can be more sensitively sensed. In addition, this embodiment collects the interference light generated by the pulsed light, the Rayleigh scattered light, and the source laser, realizing coherent detection. Coherent detection can improve the optical power compared to direct detection, thereby improving the signal-to-noise ratio.

[0053] In the foregoing detailed description, various features are combined in a single embodiment to simplify the present disclosure. This method of disclosure should not be interpreted as reflecting an intention that the embodiments of the claimed subject matter require more features than are expressly recited in each claim. On the contrary, as reflected by the appended claims, the present utility model exists in a state with fewer features than all the features of the single disclosed embodiment. Accordingly, the appended claims are hereby expressly incorporated into the detailed description, with each claim standing alone as a separate preferred embodiment of the present utility model.

[0054] The foregoing description includes examples of one or more embodiments. Of course, it is not possible to describe all possible combinations of components or methods for the purpose of describing the above embodiments, but those of ordinary skill in the art should recognize that the various embodiments can be further combined and arranged. Accordingly, the embodiments described herein are intended to cover all such changes, modifications, and variations that fall within the scope of the appended claims. In addition, with respect to the term "comprising" used in the specification or claims, the manner in which this term is encompassed is similar to the term "including," as interpreted when "including" is used as a transitional word in a claim. In addition, any use of the term "or" in the claims or specification is to be meant "non-exclusive or."

Claims

1. A hydropower station optical cable safe operation monitoring device, characterized in that: The invention comprises a pulse light unit (10), a circulator (20), a reflector (30), a detector (40), a collection card (50) and a second coupler (70), wherein: The pulse light unit (10) comprises a laser (11), a semiconductor amplifier (12), a pulse signal source (13), and a first coupler (14); an input end of the first coupler (14) is connected to the laser (11), a first output end of the first coupler (14) is connected to a first input end of the semiconductor amplifier (12), and a second output end of the first coupler (14) is connected to a first input end of the second coupler (70); The second input end of the semiconductor amplifier (12) is connected to the pulse signal source (13), and the output end is connected to the circulator (20); The circulator (20) comprises three ports, a first port connected to the output port of the pulse light unit (10), a second port connected to the first port of the water and electricity optical cable to be monitored, and a third port connected to the second end of the second coupler (70); The reflector (30) is used to be connected to the second port of the water and electricity optical cable to be monitored, and is used to reflect the pulse light at the end of the water and electricity optical cable and the Rayleigh scattered light generated by the water and electricity optical cable to be monitored back into the water and electricity optical cable to be monitored, and reach the second coupler (70) through the second port and the third port of the circulator (20); The output end of the second coupler (70) is also connected to the input end of the detector (40) and is used to interfere with the light entering the second coupler (70) to generate an interference light signal; The output end of the detector (40) is also connected to the acquisition card (50) and is used to convert the interference light signal output by the second coupler (70) into an electrical signal and send it to the acquisition card (50); The output end of the acquisition card (50) is used to connect to an external controller (80) and is used to convert the electrical signal transmitted from the detector (40) into a digital signal and send it to the external controller (80) for analysis and processing.

2. The hydropower station optical cable safe operation monitoring device according to claim 1 is characterized in that: It also includes an erbium-doped fiber amplifier (60), the input end of the erbium-doped fiber amplifier (60) is connected to the output end of the semiconductor amplifier (12), and the output end of the erbium-doped fiber amplifier (60) is connected to the first port of the circulator (20).

3. The hydropower station optical cable safe operation monitoring device according to claim 1 is characterized in that: The splitting ratio of the first coupler (14) is 9:

1.

4. The hydropower station optical cable safe operation monitoring device according to claim 1 is characterized in that: The splitting ratio of the second coupler (70) is 1:

1.

5. The hydropower station optical cable safe operation monitoring device according to claim 1 is characterized in that: The detector (40) has a bandwidth greater than 250 MHz.

6. The hydropower station optical cable safe operation monitoring device according to claim 1 is characterized in that: The laser (11) operates at a wavelength of 1550 nm.

7. A hydropower station optical cable safe operation monitoring system, characterized in that: It comprises a hydropower station optical cable safe operation monitoring device as claimed in any one of claims 1 to 5 and a controller (80) connected to the acquisition card (50).

8. The hydropower station optical cable safe operation monitoring system according to claim 7 is characterized in that: The controller (80) is also connected to the erbium-doped fiber amplifier (60) and is used to adjust the current of the erbium-doped fiber amplifier (60).

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