CN111508173A - High-voltage cable channel anti-damage early warning system - Google Patents

Abstract

The invention discloses a high-voltage cable channel anti-damage early warning system, which is applied to the technical field of pipeline detection, and particularly can visually remind a user of the excavation and damage conditions of an optical cable along the way by characters and images in the scene of cable damage and anti-theft cutting caused by third-party construction; and the optical fiber MZ interferometer transmits the interference output value to a short message notification module to edit and transmit a short message, and simultaneously transmits the interference output value to a computer terminal to convert a oscillogram.

Description

A high-voltage cable channel anti-sabotage early warning system

technical field

The invention relates to the technical field of pipeline detection, in particular to an anti-damage early warning system for a high-voltage cable channel.

Background technique

With the acceleration of the urbanization process, in addition to the increasingly tight space on the ground, the underground space is also very short. The incidents of cable damage caused by third-party construction have occurred from time to time. Due to the large number of routes and the small number of inspectors, it is difficult to detect and prevent the first The damage to the high-voltage cable channel caused by the tripartite construction. In addition, due to various reasons, the incidents of cables being stolen and cut also occur from time to time.

Although the distributed optical fiber vibration detection system has been on the market for many years, the nominal positioning accuracy is as high as 10 meters and the detection distance is more than 50km, but these indicators are all measured in the laboratory environment, and a lot of research is still needed for practical engineering applications. Work has to be done. For example, many PK tests have been carried out in PetroChina Tianjin Branch, Shengli Oilfield, Jiuzhi Optoelectronic Materials Co., Ltd. Optical Fiber Sensing Experimental Base, etc., but the actual results are not satisfactory. There is an optical fiber in the communication trunk line to monitor the excavation and damage of the optical cable along the way, and the effect is not ideal. The main reasons are as follows:

1. The distributed optical fiber vibration detection system adopts a dual MZ system, which is very sensitive to external vibration, but has a large positioning error. Therefore, most distributed optical fiber vibration detection (DAS) uses narrow linewidth laser pulse backscattering self-coherence technology. When the narrow pulse is used, the signal is very weak, and the detection is difficult; while if the wide pulse signal is used, it is easy to detect, but its spatial distribution is wide. , which actually weakens the sensitivity to external vibration signals. In the laboratory, piezoelectric ceramics are often used to extrude optical fibers at specific positions to simulate external vibrations. Some manufacturers fix a section of optical fibers on a glass plate, and use small glass balls to fall on the glass plate to simulate natural vibrations. In the underground engineering environment, the detection optical fiber is sealed in the ointment in the thick protective layer, the uneven geological structure, and the cable trench have obvious post-launch, attenuation and scattering effects on the external vibration, thus further reducing the optical fiber. Responsiveness to external vibrations.

2. This type of system is equivalent to using a light pulse to inspect the vibration of each point on the fiber. The propagation speed of light in the fiber is about 200,000 kilometers. Therefore, for a 50km fiber, the light pulse enters from the fiber end to the fiber end. , it takes at least 500 microseconds to return to the head end of the fiber along the original path, that is, the maximum inspection speed is 2 kHz. In addition, due to the weak signal and high noise, it usually needs to be accumulated and averaged more than 30 times. In 30 times, the inspection speed is It is reduced to 66 times. According to the sampling law, the maximum frequency that can be collected is only more than 30 Hz. The vibration frequency generated by an external excavation may be much higher than this value. In the laboratory, in order to obtain better measurement data, short optical fibers are often used for experiments, which can increase the sampling rate (ie, the repetition frequency), resulting in a further gap between the actual performance of such systems and the experimental conditions.

3. In addition, the price of this type of system is expensive. The price of imported equipment is more than 1 million per set, and the market price of domestic equipment is also around 800,000 per set. However, urban high-voltage transmission lines usually do not have such a long distance. Moreover, the number of high-voltage transmission channels in cities is very large. If such a system is configured, it will generate huge financial pressure on the power sector.

The existing Chinese invention patent discloses a pipeline leakage and anti-excavation warning system with patent number CN110345389A. The light emitted by the laser is divided into two paths through the main optical splitter, and two sets of branch optical splitters, two branch optical fibers, The coupler and the photoelectric converter respectively form a fiber MZ interferometer in two directions, which are monitored by two fiber MZ interferometers. At the same time, a pulsed laser, a sensing fiber, a circulator, and a photoelectric sensor are used to realize the narrow linewidth laser pulse backward. Scattering self-coherence monitoring, then enabling narrow linewidth laser pulse detection for precise detection of disturbed regions. The data information obtained by this type of system needs to be processed by computer equipment in many links before it can be used for the user's reference, and the patent specification does not disclose the function details to remind the user.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a high-voltage cable channel anti-damage early warning system whose manufacturing cost is far lower than that of the existing equipment, overcoming the problem that the system in the prior art lacks user-friendly early warning information.

In order to solve the above-mentioned technical problems, in view of the characteristics of large traffic flow and complex noise in urban high-voltage transmission channels, the present invention adopts the following technical solutions:

A high-voltage cable channel anti-damage early warning system, comprising an optical fiber vibration detector, an optical cable splicing box A, an optical cable splicing box B, a vibration detection cable, a communication optical cable A and a communication optical cable B, and the optical fiber vibration detector passes through the communication optical cable A and the optical cable splicing box. A is connected, and the optical cable splice box A is connected to the optical cable splice box B through the vibration detection cable and the communication optical cable B arranged side by side. The optical fiber vibration detector has a built-in optical fiber MZ interferometer. Processing circuit, the light emitted by the laser is transmitted to the signal acquisition and processing circuit through the vibration detection cable, and the signal acquisition and processing circuit converts the optical signal into an electrical signal and generates an interference output value. The optical fiber MZ interferometer passes the generated interference output value through the network. It is transmitted to the computer terminal to generate a waveform image; the optical fiber MZ interferometer has a built-in short message notification module, and the short message notification module is provided with an early warning value of the interference output value. , edited and sent to a mobile device.

当光在传输过程中会受到外部冲击力或振动的作用时，由于两根空间位置不同，所受到的冲击也不同，产生的折射率改变也不同，导致两束光的相位差发生变化。所述振动探测缆和通讯光缆B连通两地的光缆接续盒，实现振动信号的传送。信号采集处理电路将收集到的光信号转成电信号，并通过计算电路生成干涉输出值，经通讯光缆传给计算机终端；计算机终端将实时接收到的干涉输出值借助波形生成软件生成波形图。另外，短信通知模块设置了干涉输出值的，排除了不必要的预警短信通知。总之，所述高压电缆通道防破坏预警系统制造成本相对较低，能够实现对电缆管道沿路振动情况的监测。通过在光纤振动探测器中使用光纤MZ干涉技术，并通过振动探测缆和通讯光缆B来传送信号，经短信通知模块对信号的处理，以可视化的文字或者图像形式，通过短信通知到巡查人员或利用网络将报警数据发送至运维中心，信息内容包括具体振动影响大小和发生点位置等信息。The principle of the optical fiber MZ interference technology used in the optical fiber vibration detector is as follows: the beam output from the laser is divided into two coherent beams of the same intensity through a 3dB beam splitter and respectively passes through the two fiber arms. Physically identical, the two beams of light will have a fixed phase difference when they reach the second coupler

When the light is subjected to external impact force or vibration during the transmission process, due to the different spatial positions of the two beams, the impact received is also different, and the resulting refractive index changes are also different, resulting in a change in the phase difference between the two beams of light. The vibration detection cable and the communication optical cable B are connected to the optical cable junction box of the two places to realize the transmission of the vibration signal. The signal acquisition and processing circuit converts the collected optical signals into electrical signals, and generates the interference output value through the calculation circuit, which is transmitted to the computer terminal through the communication optical cable; the computer terminal uses the waveform generation software to generate the waveform diagram from the interference output value received in real time. In addition, if the SMS notification module sets the interference output value, unnecessary warning SMS notifications are excluded. In a word, the manufacturing cost of the high-voltage cable channel anti-damage early warning system is relatively low, and it can monitor the vibration of the cable channel along the road. The optical fiber MZ interference technology is used in the optical fiber vibration detector, and the signal is transmitted through the vibration detection cable and the communication optical fiber cable B, and the signal is processed by the SMS notification module, in the form of visual text or image. Use the network to send the alarm data to the operation and maintenance center, and the information content includes information such as the specific vibration impact size and the location of the occurrence point.

Further, the optical fiber vibration detector further includes a fiber breaking alarm relay, and the fiber breaking alarm relay is switched on when the vibration detection cable is disconnected to generate an alarm signal.

式中I为干涉输出值，I₁，I₂分别是相同的两束相关光的强度，Δs(t)是外界因素作用到两条光纤上引起的相位差，

是无外界因素下两束光的相位差。Further, the calculation formula of the interference output of the optical fiber vibration detector is:

where I is the interference output value, I ₁ , I ₂ are the intensities of the same two correlated beams respectively, Δs(t) is the phase difference caused by external factors acting on the two fibers,

is the phase difference between the two beams of light without external factors.

式中ξ为调制强度，ω为外界调制频率。Further, when the external signal is a periodic vibration signal, the calculation formula of the interference output of the optical fiber vibration detector is:

where ξ is the modulation intensity, and ω is the external modulation frequency.

Further, a network camera is also included. The network camera is connected to the optical cable splice box B through an RJ45 network cable, and is used to obtain real-time video information around the optical cable splice box B, and transmit the real-time video information to the data center through the communication optical cable B.

Further, the vibration detection cable is suspended on the manhole cover.

Further, the optical fiber vibration detector has a built-in power supply module, and the power supply module supplies power for the optical fiber MZ interferometer, the short message notification module and the fiber break alarm relay.

The technical scheme adopted by the present invention has the following beneficial effects: when monitoring the vibration around the cable, by using the optical fiber MZ interferometer and the short message notification module, the vibration attribute value is sent to the computer terminal, and an image is generated, and the vibration is relatively suspicious. Send a short message to a designated mobile device to remind the user of the excavation and damage along the way of the optical cable in a visual way, and at the same time, the manufacturing cost of the early warning system is far lower than the early warning system of the prior art.

The specific technical solutions adopted in the present invention and the beneficial effects brought by them will be disclosed in detail in the following specific embodiments in conjunction with the accompanying drawings.

Description of drawings

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

Figure 1 is a system structure diagram of a high-voltage cable channel anti-sabotage early warning system.

Figure 2 is a schematic diagram of the MZ fiber interferometer.

Figure 3 is a waveform diagram of tapping the pipe.

Figure 4 is a waveform diagram when the electric pick hits the ground.

Description of reference numerals: 1. Optical fiber vibration detector; 11. SMS notification module; 11. Optical fiber MZ interferometer; 2. Communication optical cable A; 3. Optical cable splice box A; 4. Communication optical cable B; 5. Vibration detection cable; 6. Optical cable connection box B; 7. Network camera; 8. Cable conduit.

Detailed ways

The technical solutions of the embodiments of the present invention will be explained and described below with reference to the accompanying drawings of the embodiments of the present invention, but the following embodiments are only preferred embodiments of the present invention, not all. Based on the examples in the implementation manner, other examples obtained by those skilled in the art without creative work shall fall within the protection scope of the present invention.

It can be understood by those skilled in the art that the features in the following embodiments and implementations can be combined with each other without conflict.

The terminology used in the present invention is for the purpose of describing particular embodiments only and is not intended to limit the present invention. For example, the following words such as "upper", "inner", "outer", etc. indicating orientation or positional relationship are only based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying References to devices/elements must have a particular orientation or be constructed and operated in a particular orientation and are therefore not to be construed as limitations of the invention.

In the present invention, unless otherwise expressly specified and limited, terms such as "installation" and "connection" should be understood in a broad sense, for example, it may be a fixed connection, a detachable connection, or an integral connection; it may be The mechanical connection can also be an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

A high-voltage cable channel anti-damage early warning system described in the embodiment of the present invention, as shown in FIG. 1, includes: an optical fiber vibration detector 1, a communication optical cable A2, an optical cable splice box A3, a communication optical cable B4, a vibration detection cable 5, an optical fiber cable Connection box B6, network camera 7. The optical fiber vibration detector 1 is arranged in a cable well or an equipment box, and is connected to an optical cable splicing box A3 through a communication optical cable A2, and the optical cable splicing box A3 and the remote optical cable splicing box B6 through the vibration detection cable 5 and the communication optical cable B4. connect. The vibration detection cable 5 and the communication optical cable B4 are deployed beside the transmission cable or in the spare pipe hole to monitor the vibration signal around the channel in real time. Once an abnormality is found, the signal is transmitted quickly.

The optical fiber vibration detector 1 has a built-in optical fiber MZ interferometer 12 and a short message notification module 11. The optical fiber MZ interferometer 12 is provided with a laser and a signal acquisition and processing circuit, and the light emitted by the laser is transmitted to the signal acquisition and processing circuit through the vibration detection cable 5. The signal acquisition and processing circuit converts the optical signal into an electrical signal and generates an interference output value. The optical fiber MZ interferometer 12 directly transmits the generated interference output value to the SMS notification module 11 for processing, and transmits it to the computer through the communication optical cable. The terminal is used to generate a waveform image, and translate the obscure machine language into a human-recognizable graphic pattern, and intuitively reflect the external vibration signal on the graphic curve; the short message notification module 11 is provided with an interferometric output value. For the early warning value, the interference output value transmitted by the optical fiber MZ interferometer 12 is filtered through the comparison circuit, and the interference output value exceeding the early warning value is edited and sent to the mobile device according to the pre-made short message template. Notifying the inspectors through SMS or sending the alarm data to the inspection personnel in the operation and maintenance center through the network can let the inspectors know the excavation situation around the cable in real time.

Figure 2 is the schematic diagram of the MZ fiber interferometer. The beam output from the laser is divided into two coherent beams of the same intensity through a 3dB beam splitter and passes through the two fiber arms respectively. Since the two fibers cannot be physically identical, the two When the beam of light reaches the second coupler, a fixed phase difference will be generated. When the light is subjected to external impact force or vibration during the transmission process, due to the different spatial positions of the two wires, the impact received is also different, resulting in The refractive index changes of the two beams are also different, resulting in a change in the phase difference between the two beams of light. Thus, the present embodiment provides a method for calculating the interference output values of aperiodic vibration and periodic vibration in the optical fiber MZ interferometer 12 .

In the application of optical fiber MZ interference technology, the interference output of ordinary knocking or vibration is calculated according to the following formula:

是无外界因素下两束光的相位差。在本实施例中，振动探测缆5部署在排管内，实施人员用铁锤敲击排管，通过上述非周期性振动的干涉输出值计算方法生成干涉输出值并经示波器模块11进行数据处理转化成波形图，如图3所示为本实施例在电缆排管敲击实验中得到的敲击排管波形图。where I is the interference output value, I ₁ , I ₂ are the intensities of the same two correlated beams respectively, Δs(t) is the phase difference caused by external factors acting on the two fibers,

is the phase difference between the two beams of light without external factors. In this embodiment, the vibration detection cable 5 is deployed in the row pipe, and the operator hits the row pipe with a hammer, generates the interference output value through the above-mentioned aperiodic vibration interference output value calculation method, and performs data processing and conversion through the oscilloscope module 11 A waveform diagram is formed, as shown in FIG. 3 , the waveform diagram of the tapping pipe obtained in the tapping experiment of the cable pipe in this embodiment.

When the external signal is a periodic vibration signal, this embodiment uses an electric pick to impact the ground to generate periodic vibration. At this time, the interference output of the optical fiber vibration detector 1 is calculated according to the following formula:

In the formula, ξ is the modulation intensity, and ω is the external modulation frequency. It can be seen that the relationship between the interference output signal and the shock signal ξcos(ωt) is not a one-to-one correspondence of single-valued functions, but is very complex. Therefore, when the system is applied to In the actual perimeter alert, the field usually adopts the frequency domain method or the event database method to determine whether there is an intrusion. The interference output value is generated by the above method for calculating the interference output value of periodic vibration, and the oscilloscope module 11 performs data processing to convert it into a vibration waveform diagram generated when the electric pick hits the ground as shown in FIG. 4 .

Once the inspectors or the operation and maintenance center find suspicious information, they will go to the scene to confirm and stop the ongoing cable damage incident. In order to more easily find the specific location of the point where the damaged cable occurs, the installer can divide the cable to be monitored into several sections, and the length of each section is allocated according to the needs. 7, in order to realize video linkage and video evidence collection, and transmit all data to the data center through the communication optical cable B transmission, so as to facilitate the same management and scheduling.

In addition, the optical fiber vibration detector 1 also includes a fiber break alarm relay, which closes the switch when the vibration detection cable is disconnected to generate an alarm signal, and the holding contact on the fiber break alarm relay can continue to be closed until the fiber break connection is intact. The closing time of the alarm relay can be adjusted within the range of 500ms to 3000ms according to the needs of the project. In this way, the closing time of the alarm relay can be set to remind the inspectors to the greatest extent. When the cable damage event cannot be dealt with in the future and the vibration detection cable is cut off by others, the fiber break alarm relay is closed, and the alarm information is sent to the operation and maintenance center through the fiber vibration detector 1 to generate an alarm. The optical fiber vibration detector 1 has a built-in power supply module, and the power supply module supplies power for the optical fiber MZ interferometer 12, the short message notification module 11 and the fiber break alarm relay.

As an optional installation method and configuration scheme in this embodiment, the optical cable splice box A3 and the optical cable splice box B6 are selected to be buried type, and can also be replaced by indoor type; the vibration detection cable 5 is deployed next to the transmission cable, and can also be deployed In the spare pipe hole, the vibration signal around the channel is monitored in real time; the fiber-optic vibration detector 1 is powered by solar energy, and can also use inductive power extraction; the early warning system in this embodiment can provide 24-hour response, and during equipment maintenance, it can be replaced with the same The vibration detection cable 5 is suspended on the manhole cover, and the system is in an armed state. Once the manhole cover is opened, the optical cable suspended on it will vibrate, which will be captured by the alarm system and accurately positioned.

In a word, a high-voltage cable channel anti-sabotage early warning system described in this embodiment uses the optical fiber MZ interference technology and adds a short message notification module 11 to send short messages and original waveform image data to the inspectors or the operation and maintenance center to remind in a visual way. Excavation and damage of the user's optical cable along the way, and at the same time, the manufacturing cost of the early warning system is far lower than the early warning system of the prior art, which reduces the financial pressure of the power sector.

The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that the present invention includes but is not limited to the drawings and the descriptions in the above specific embodiments. content. Any modifications that do not depart from the functional and structural principles of the present invention are intended to be included within the scope of the claims.

Claims (7)

1. The utility model provides a high tension cable passageway prevents destroying early warning system, includes optical fiber vibration detector, optical cable splice closure A, optical cable splice closure B, vibration detection cable, communication optical cable A and communication optical cable B, and optical fiber vibration detector passes through communication optical cable A and links to each other with optical cable splice closure A, and optical cable splice closure A links to each other its characterized in that through vibration detection cable and communication optical cable B that set up side by side with optical cable splice closure B:

an optical fiber MZ interferometer is arranged in the optical fiber vibration detector, the optical fiber MZ interferometer is provided with a laser and a signal acquisition and processing circuit, light emitted by the laser is transmitted to the signal acquisition and processing circuit through a vibration detection cable, the signal acquisition and processing circuit converts optical signals into electric signals and generates interference output values, and the optical fiber MZ interferometer transmits the generated interference output values to a computer terminal through a network for generating waveform images;

the optical fiber MZ interferometer is internally provided with a short message notification module, the short message notification module is provided with an early warning value of an interference output value, and the interference output value exceeding the early warning value is edited and sent to the mobile equipment according to a prefabricated short message template through comparison.

2. The anti-damage early warning system of a high-voltage cable channel according to claim 1, characterized in that: the optical fiber vibration detector also comprises a fiber breaking alarm relay, and the switch of the fiber breaking alarm relay is closed when the vibration detection cable is disconnected to generate an alarm signal.

3. The anti-damage early warning system of a high-voltage cable channel according to claim 1, characterized in that: the interference output calculation formula of the optical fiber vibration detector is

Wherein I is the interference output value, I₁，I₂Respectively the intensity of two identical beams of related light, deltas (t) is the phase difference caused by external factors acting on the two optical fibers,

is the phase difference of two beams of light without external factors.

4. The anti-damage early warning system of claim 3, wherein: when the external signal is a periodic vibration signal, the interference output calculation formula of the optical fiber vibration detector is

Where ξ is the modulation intensity and ω is the ambient modulation frequency.

5. The anti-damage early warning system of a high-voltage cable channel according to claim 1, characterized in that: the network camera is connected with the optical cable junction box B through an RJ45 network cable and used for acquiring real-time video information on the periphery of the optical cable junction box B and transmitting the real-time video information to the data center through the communication optical cable B.

6. The anti-damage early warning system for the high-voltage cable channel according to any one of claims 1 to 5, wherein: the vibration detection cable is suspended from the well cover.

7. The anti-damage early warning system for the high-voltage cable channel according to any one of claims 2 to 5, wherein: the optical fiber vibration detector is internally provided with a power supply module which supplies power for the optical fiber MZ interferometer, the short message notification module and the fiber breakage alarm relay.

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