State detection method and device for cable intermediate joint, and storage medium

Abstract

The invention discloses a state detection method and device for a cable intermediate joint and a storage medium, and the method comprises the steps: controlling a bandwidth light source to emit an original optical signal, and enabling the original optical signal to enter a fiber Bragg grating sensor through the coupling of a circulator; the fiber bragg grating sensor is controlled to reflect a target optical signal, and the target optical signal is coupled into the long-period fiber bragg grating sensor through the circulator; and detecting the state of the cable intermediate joint according to the detection long-period fiber grating sensor and / or the target optical signal. According to the embodiment of the invention, the circulator is used for transferring optical signals, so that the cost can be reduced, the device can be conveniently deployed in the cable intermediate joint, the state detection of the cable intermediate joint is realized by using the principle of the grating sensor, the automation degree is high, the labor cost is reduced, the device has the characteristic of real-time monitoring, and the efficiency of detecting the state of the cable intermediate joint is effectively improved.

Description

Technical Field

[0001] The present invention relates to the field of electric power technology, and in particular to a state detection method, device and storage medium for a cable intermediate joint. Background Art

[0002] With the continuous improvement of modernization construction, electricity applications have entered thousands of households. Cables, as infrastructure and connecting components for the transmission and distribution of electric energy, are widely distributed and used. The safe and reliable operation of cables plays a positive role in the stable operation of power systems.

[0003] Due to the long length of the cable, during the design and construction, cable intermediate joints are used to connect multiple cable sections to form an electrical connection.

[0004] Cable intermediate joints often face various faults. For example, since cable intermediate joints adopt a splicing connection method, there is a risk of heat generation when the contact is poor. Since cable intermediate joints are buried in cable trenches, large machinery and equipment on the ground may cause external force damage to the cable intermediate joints, etc. These faults can cause danger to the cables.

[0005] At present, manual inspection is generally used to troubleshoot cable intermediate joints, which is costly and inefficient. Summary of the invention

[0006] In view of this, the present invention provides a method, device and storage medium for detecting the state of an intermediate cable joint, so as to detect the efficiency of the state of the intermediate cable joint.

[0007] A first aspect of the present invention provides a method for detecting the state of a cable intermediate joint, wherein the cable intermediate joint has a broadband light source, a circulator, a fiber Bragg grating sensor and a long-period fiber grating sensor, and the method comprises:

[0008] Controlling the broadband light source to emit an original optical signal, wherein the original optical signal is coupled into the fiber Bragg grating sensor through the circulator;

[0009] Controlling the fiber Bragg grating sensor to reflect a target optical signal, wherein the target optical signal is coupled into the long-period fiber Bragg grating sensor through the circulator;

[0010] The state of the cable intermediate joint is detected by detecting the long-period fiber grating sensor and / or the target optical signal.

[0011] Optionally, controlling the broadband light source to emit an original optical signal comprises:

[0012] Controlling the broadband light source to emit an original optical signal that meets the emission conditions;

[0013] The emission conditions include a central wavelength of 1550nm, a loudness of 3dB, a bandwidth of 52nm, and a power of 0.2mW.

[0014] Optionally, controlling the fiber Bragg grating sensor to reflect the target light signal comprises:

[0015] Control the fiber Bragg grating sensor to reflect a target light signal that meets a reflection condition;

[0016] The reflection conditions include a central wavelength of 1550 nm, a loudness of 3 dB, a bandwidth of 0.138 nm, and a reflectivity of more than 90%.

[0017] Optionally, the long-period fiber grating sensor is attached to the inner side of the cable trench cover above the cable intermediate joint.

[0018] Optionally, the detecting the state of the cable intermediate joint according to the long period fiber grating sensor and / or the target optical signal comprises:

[0019] The deformation distance when the grating in the long-period fiber grating sensor is deformed is detected; the deformation distance is the maximum distance between the state where the grating in the long-period fiber grating sensor is deformed and the initial state;

[0020] Calculating the deflection of the grating in the long-period fiber grating sensor according to the deformation distance;

[0021] Taking the inverse of the deflection as the first curvature of the grating in the long-period fiber grating sensor;

[0022] Calculating a second curvature of the grating in the long-period fiber grating sensor according to the optical power of the target optical signal; the second curvature is positively correlated with the optical power;

[0023] Whether the cable intermediate joint is damaged by external force is detected according to the difference between the first curvature and the second curvature.

[0024] Optionally, the deflection is expressed as:

[0025]

[0026] Wherein, R is the deflection, a is the initial length of the grating in the long-period fiber grating sensor, and h is the deformation distance.

[0027] Optionally, the detecting the state of the cable intermediate joint according to the long period fiber grating sensor and / or the target optical signal comprises:

[0028] Detecting an initial wavelength of the target optical signal;

[0029] Detecting a wavelength offset value of the target optical signal;

[0030] Calculating the ratio between the wavelength offset value and the initial wavelength to obtain a wavelength change;

[0032] The temperature variation of the long period fiber grating sensor is calculated according to the wavelength variation as the temperature variation of the cable intermediate joint; under the condition that the long period fiber grating sensor is fixed, the temperature variation is positively correlated with the wavelength variation.

[0033] Optionally, the temperature variation is expressed as:

[0034]

[0035] Wherein, Δλ is the wavelength offset value, λ is the initial wavelength, α is the coefficient of variation between the grating pitch of the grating in the long period fiber grating sensor and the temperature, ε is the thermo-optic coefficient of the grating in the long period fiber grating sensor, and ΔT is the temperature variation.

[0036] The second aspect of the present invention provides a state detection device for a cable intermediate joint, in which there are a broadband light source, a circulator, a fiber Bragg grating sensor and a long-period fiber grating sensor, and the device comprises:

[0037] An original optical signal transmitting module, used for controlling the broadband light source to transmit an original optical signal, wherein the original optical signal is coupled into the fiber Bragg grating sensor through the circulator;

[0038] A target optical signal reflection module, used for controlling the fiber Bragg grating sensor to reflect a target optical signal, wherein the target optical signal is coupled into the long-period fiber Bragg grating sensor through the circulator;

[0039] The connector state detection module is used to detect the state of the intermediate connector of the cable based on detecting the long-period fiber grating sensor and / or the target optical signal.

[0040] Optionally, the original optical signal transmitting module is further used for:

[0041] Controlling the broadband light source to emit an original optical signal that meets the emission conditions;

[0042] The emission conditions include a central wavelength of 1550nm, a loudness of 3dB, a bandwidth of 52nm, and a power of 0.2mW.

[0043] Optionally, the target optical signal reflection module is further used for:

[0044] Control the fiber Bragg grating sensor to reflect a target light signal that meets a reflection condition;

[0045] The reflection conditions include a central wavelength of 1550 nm, a loudness of 3 dB, a bandwidth of 0.138 nm, and a reflectivity of more than 90%.

[0046] Optionally, the long-period fiber grating sensor is attached to the inner side of the cable trench cover above the cable intermediate joint.

[0047] Optionally, the joint status detection module includes:

[0048] A deformation distance detection module, used for detecting the deformation distance of the grating in the long-period fiber grating sensor when the grating is deformed; the deformation distance is the maximum distance between the state where the grating in the long-period fiber grating sensor is deformed and the initial state;

[0049] A deflection calculation module, used for calculating the deflection of the grating in the long-period fiber grating sensor according to the deformation distance;

[0050] A first curvature calculation module, used for taking the inverse of the deflection as the first curvature of the grating in the long-period fiber grating sensor;

[0051] A second curvature calculation module, used for calculating a second curvature of the grating in the long-period fiber grating sensor according to the optical power of the target optical signal; the second curvature is positively correlated with the optical power;

[0052] The external force damage detection module is used to detect whether the cable intermediate joint is damaged by external force according to the difference between the first curvature and the second curvature.

[0053] Optionally, the deflection is expressed as:

[0054]

[0055] Wherein, R is the deflection, a is the initial length of the grating in the long-period fiber grating sensor, and h is the deformation distance.

[0056] Optionally, the joint status detection module includes:

[0057] An initial wavelength detection module, used to detect the initial wavelength of the target optical signal;

[0058] A wavelength offset value detection module, used to detect the wavelength offset value of the target optical signal;

[0059] A wavelength change calculation module, used to calculate the ratio between the wavelength offset value and the initial wavelength to obtain the wavelength change;

[0060] The temperature variation calculation module is used to calculate the temperature variation of the long-period fiber grating sensor according to the wavelength variation as the temperature variation of the intermediate joint of the cable; when the long-period fiber grating sensor is fixed, the temperature variation is positively correlated with the wavelength variation.

[0061] Optionally, the temperature variation is expressed as:

[0062]

[0063] Wherein, Δλ is the wavelength offset value, λ is the initial wavelength, α is the coefficient of variation between the grating pitch of the grating in the long period fiber grating sensor and the temperature, ε is the thermo-optic coefficient of the grating in the long period fiber grating sensor, and ΔT is the temperature variation.

[0064] A third aspect of the present invention provides an electronic device, the electronic device comprising:

[0065] at least one processor; and

[0066] a memory communicatively connected to the at least one processor; wherein,

[0067] The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the method for detecting the status of the cable intermediate joint as described in the first aspect above.

[0068] A fourth aspect of the present invention provides a computer-readable storage medium storing a computer program, wherein the computer program, when executed by a processor, implements the method for detecting the state of an intermediate cable joint as described in the first aspect above.

[0069] A fifth aspect of the present invention provides a computer program product, which includes a computer program. When the computer program is executed by a processor, the method for detecting the state of an intermediate cable joint as described in the first aspect above is implemented.

[0070] In this embodiment, the broadband light source is controlled to emit the original light signal, and the original light signal is coupled into the fiber Bragg grating sensor through the circulator; the fiber Bragg grating sensor is controlled to reflect the target light signal, and the target light signal is coupled into the long-period fiber grating sensor through the circulator; the state of the cable intermediate joint is detected based on the detection of the long-period fiber grating sensor and / or the target light signal. This embodiment uses a circulator to transfer the light signal, which can reduce costs and is easy to deploy at the cable intermediate joint. The principle of the grating sensor is used to realize the state detection of the cable intermediate joint, with a high degree of automation, reduced labor costs, and the characteristics of real-time monitoring, which effectively improves the efficiency of detecting the state of the cable intermediate joint.

[0071] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0073] Figure 1 This is a flow chart of a method for detecting the status of a cable intermediate joint provided in Embodiment 1 of the present invention.

[0074] Figure 2 It is a schematic diagram of a grating deformation provided in the first embodiment of the present invention.

[0075] Figure 3 It is a structural schematic diagram of a state detection device for a cable intermediate joint provided in Embodiment 2 of the present invention.

[0076] Figure 4 It is a structural schematic diagram of an electronic device provided in Embodiment 3 of the present invention. DETAILED DESCRIPTION

[0077] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0078] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present invention described herein can cover sequential implementations other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0079] Embodiment 1

[0080] See also Figure 1 , showing a flow chart of a method for detecting the status of an intermediate cable joint provided in Embodiment 1 of the present invention. The method can be executed by a state detection device for an intermediate cable joint. The state detection device for an intermediate cable joint can be implemented in the form of hardware and / or software. The state detection device for an intermediate cable joint can be configured in an electronic device.

[0081] In this embodiment, the cable intermediate joint contains a broadband light source, a circulator, a fiber Bragg grating sensor (FBG) and a long-period fiber grating sensor (LPFG), a photodetector, and pre-processing circuits such as an amplifier, a filter, and an analog-to-digital conversion circuit.

[0082] Among them, the long-period fiber grating sensor is attached to the inner side of the cable trench cover above the middle joint of the cable.

[0083] Furthermore, fiber Bragg grating is a fiber device that forms a permanent periodic change in the refractive index in the fiber core by a certain method. In essence, it is a section of fiber whose core refractive index changes periodically. According to the size of the period, it is divided into fiber Bragg grating and long-period fiber grating. The period of fiber Bragg grating FBG is in the micron level (light wavelength level), and the period of long-period fiber grating LPFG is tens of microns or hundreds of microns.

[0084] like Figure 1 As shown, the method includes:

[0085] Step 101: Control a broadband light source to transmit an original optical signal.

[0086] In this embodiment, the bandwidth light source can be controlled to emit the original optical signal according to a certain frequency, and the original optical signal is coupled into the fiber Bragg grating sensor FBG through the circulator.

[0087] In a specific implementation, the bandwidth light source can be controlled to emit an original light signal that meets the emission conditions.

[0088] The emission conditions include a central wavelength of 1550nm, a loudness of 3dB, a bandwidth of 52nm, and a power of 0.2mW.

[0089] Step 102: Control the fiber Bragg grating sensor to reflect the target light signal.

[0090] In the fiber Bragg grating sensor FBG, the period and refractive index change due to the effects of temperature, stress, electromagnetic force, etc., causing the wavelength of the original optical signal to shift and reflect the target optical signal outward. The target optical signal is coupled into the long period fiber grating sensor LPFG through the circulator.

[0091] In a specific implementation, the fiber Bragg grating sensor is controlled to reflect the target light signal that meets the reflection condition.

[0092] The reflection conditions include a central wavelength of 1550 nm, a loudness of 3 dB, a bandwidth of 0.138 nm, and a reflectivity of more than 90%.

[0093] Since the cost of the regulator used with the long period fiber grating sensor LPFG is relatively high, the cost can be reduced by using the fiber Bragg grating sensor FBG to reflect a suitable target light signal to the long period fiber grating sensor LPFG.

[0094] The target optical signal passes through the long period fiber grating sensor LPFG and then transmits into the photodetector. The photodetector converts the optical signal into an electrical signal. The electrical signal enters the preprocessing circuits such as the amplifier, filter, analog-to-digital conversion circuit, etc. for amplification, filtering, analog-to-digital conversion, etc. to obtain the target optical signal in the form of a digital signal.

[0095] Step 103: Detect the state of the cable intermediate joint based on the detection of the long-period fiber grating sensor and / or the target optical signal.

[0096] When the state of the cable intermediate joint changes, the spectrum signal of the long period fiber grating sensor LPFG and its target optical signal usually changes. Therefore, the state of the cable intermediate joint can be detected according to the long period fiber grating sensor LPFG and / or the target optical signal.

[0097] In one embodiment of the present invention, step 103 may include the following steps:

[0098] Step 1031: Detect the deformation distance of the grating in the long-period fiber grating sensor when the grating is deformed.

[0099] When the middle joint of the cable is damaged by external force, the long period fiber grating sensor LPFG deployed in the middle joint of the cable often deforms. At this time, the deformation distance of the grating in the long period fiber grating sensor LPFG can be detected during the deformation.

[0100] The deformation distance is the maximum distance between the deformed state and the initial state of the grating in the long period fiber grating sensor LPFG.

[0101] Generally, the gratings in the long period fiber grating sensor LPFG are initially on a uniform plane, and the deformation distance is the distance between the vertex and the plane when the gratings in the long period fiber grating sensor LPFG are deformed (mainly bent).

[0102] Step 1032: Calculate the deflection of the grating in the long-period fiber grating sensor according to the deformation distance.

[0103] In this embodiment, the initial structural parameters of the grating in the long period fiber grating sensor LPFG can be queried, and the deflection of the grating in the long period fiber grating sensor LPFG when deformed can be calculated by combining the initial structural parameters of the grating in the long period fiber grating sensor LPFG with the deformation distance.

[0104] For example, Figure 2 As shown, the initial structural parameters of the grating in the long period fiber grating sensor LPFG include the initial length of the grating in the long period fiber grating sensor LPFG, then the deflection is expressed as:

[0105]

[0106] Where R is the deflection, a is the initial length of the grating in the long period fiber grating sensor LPFG, and h is the deformation distance.

[0107] Step 1033: Take the inverse of the deflection as the first curvature of the grating in the long-period fiber grating sensor.

[0108] In this embodiment, the inverse of the deflection R can be calculated as the first curvature C1 of the grating in the long period fiber grating sensor LPFG, that is, C1=1 / R.

[0109] Step 1034: Calculate the second curvature of the grating in the long-period fiber grating sensor according to the optical power of the target optical signal.

[0110] In this embodiment, the optical power of the target optical signal received by the long-period fiber grating sensor LPFG can be queried, and the optical power of the target optical signal can be used to calculate the second curvature of the grating in the long-period fiber grating sensor, wherein the second curvature is positively correlated with the optical power, that is, the higher the optical power, the greater the second curvature, and conversely, the lower the optical power, the smaller the second curvature.

[0111] Exemplarily, the relationship between the optical power P of the target optical signal received by the long period fiber grating sensor LPFG and the second curvature C2 of the grating in the long period fiber grating sensor LPFG is P=-19.87712+6.31228*C2.

[0112] Step 1035: Detect whether the intermediate joint of the cable is damaged by external force based on the difference between the first curvature and the second curvature.

[0113] In this embodiment, the difference between the first curvature and the second curvature (such as the difference between the two, the degree of deviation between the two, etc.) can be calculated, and whether the cable intermediate joint is damaged by external force can be detected based on the difference between the first curvature and the second curvature.

[0114] Generally speaking, if the difference between the first curvature and the second curvature is greater than or equal to a preset threshold, it can be determined that the intermediate joint of the cable is damaged by external force; if the difference between the first curvature and the second curvature is less than the preset threshold, it can be determined that the intermediate joint of the cable is not damaged by external force.

[0115] In another embodiment of the present invention, step 103 may include the following steps:

[0116] Step 1036: Detect the initial wavelength of the target optical signal.

[0117] In this embodiment, when the long period fiber grating sensor LPFG initially receives the target light signal, the wavelength of the target light signal is recorded as the initial wavelength.

[0118] Step 1037: Detect the wavelength offset value of the target optical signal.

[0119] In this embodiment, the wavelength of the target optical signal received by the long period fiber grating sensor LPFG is equivalent to the deviation of the initial wavelength to obtain the wavelength deviation value.

[0120] Step 1038: Calculate the ratio between the wavelength offset value and the initial wavelength to obtain the wavelength change.

[0121] The wavelength shift value is used as the numerator and the initial wavelength is used as the denominator to calculate the ratio between the wavelength shift value and the initial wavelength to obtain the wavelength change.

[0122] Step 1039: Calculate the temperature change of the long-period fiber grating sensor according to the wavelength change, and use it as the temperature change of the middle joint of the cable.

[0123] In this embodiment, the temperature variation of the long-period fiber grating sensor can be calculated according to the wavelength variation as the temperature variation of the intermediate joint of the cable.

[0124] Among them, under the condition that the long-period fiber grating sensor is fixed, the temperature change is positively correlated with the wavelength change, that is, the greater the wavelength change, the greater the temperature change, and vice versa, the smaller the wavelength change, the smaller the temperature change.

[0125] Exemplarily, the temperature change is expressed as:

[0126]

[0127] Among them, Δλ is the wavelength offset value, λ is the initial wavelength, α is the coefficient of variation between the grating pitch and temperature in the long-period fiber Bragg grating sensor (used to describe the variation coefficient of the grating pitch with temperature), ε is the thermo-optic coefficient of the grating in the long-period fiber Bragg grating sensor (used to describe the variation relationship between the grating refractive index and temperature), and ΔT is the temperature change.

[0128] In this embodiment, the broadband light source is controlled to emit the original light signal, and the original light signal is coupled into the fiber Bragg grating sensor through the circulator; the fiber Bragg grating sensor is controlled to reflect the target light signal, and the target light signal is coupled into the long-period fiber grating sensor through the circulator; the state of the cable intermediate joint is detected based on the detection of the long-period fiber grating sensor and / or the target light signal. This embodiment uses a circulator to transfer the light signal, which can reduce costs and is easy to deploy at the cable intermediate joint. The principle of the grating sensor is used to realize the state detection of the cable intermediate joint, with a high degree of automation, reduced labor costs, and the characteristics of real-time monitoring, which effectively improves the efficiency of detecting the state of the cable intermediate joint.

[0129] Embodiment 2

[0130] See also Figure 3 , shows a schematic diagram of the structure of a state detection device for a cable intermediate joint provided by the second embodiment of the present invention. The cable intermediate joint includes a broadband light source, a circulator, a fiber Bragg grating sensor and a long-period fiber grating sensor, such as Figure 3 As shown, the device comprises:

[0131] The original optical signal transmitting module 301 is used to control the broadband light source to transmit the original optical signal, and the original optical signal is coupled into the fiber Bragg grating sensor through the circulator;

[0132] A target optical signal reflection module 302 is used to control the fiber Bragg grating sensor to reflect the target optical signal, and the target optical signal is coupled into the long-period fiber Bragg grating sensor through the circulator;

[0133] The connector state detection module 303 is used to detect the state of the intermediate connector of the cable by detecting the long-period fiber grating sensor and / or the target optical signal.

[0134] In one embodiment of the present invention, the original optical signal transmitting module 301 is further used for:

[0135] Controlling the broadband light source to emit an original optical signal that meets the emission conditions;

[0136] The emission conditions include a central wavelength of 1550nm, a loudness of 3dB, a bandwidth of 52nm, and a power of 0.2mW.

[0137] In one embodiment of the present invention, the target optical signal reflection module 302 is further used for:

[0138] Control the fiber Bragg grating sensor to reflect a target light signal that meets a reflection condition;

[0139] The reflection conditions include a central wavelength of 1550 nm, a loudness of 3 dB, a bandwidth of 0.138 nm, and a reflectivity of more than 90%.

[0140] In one embodiment of the present invention, the long-period fiber grating sensor is attached to the inner side of the cable trench cover above the cable intermediate joint.

[0141] In one embodiment of the present invention, the joint status detection module 303 includes:

[0142] A deformation distance detection module, used for detecting the deformation distance of the grating in the long-period fiber grating sensor when the grating is deformed; the deformation distance is the maximum distance between the state where the grating in the long-period fiber grating sensor is deformed and the initial state;

[0143] A deflection calculation module, used for calculating the deflection of the grating in the long-period fiber grating sensor according to the deformation distance;

[0144] A first curvature calculation module, used for taking the inverse of the deflection as the first curvature of the grating in the long-period fiber grating sensor;

[0145] A second curvature calculation module, used for calculating a second curvature of the grating in the long-period fiber grating sensor according to the optical power of the target optical signal; the second curvature is positively correlated with the optical power;

[0146] The external force damage detection module is used to detect whether the cable intermediate joint is damaged by external force according to the difference between the first curvature and the second curvature.

[0147] In one embodiment of the present invention, the deflection is expressed as:

[0148]

[0149] Wherein, R is the deflection, a is the initial length of the grating in the long-period fiber grating sensor, and h is the deformation distance.

[0150] In another embodiment of the present invention, the joint status detection module 303 includes:

[0151] An initial wavelength detection module, used to detect the initial wavelength of the target optical signal;

[0152] A wavelength offset value detection module, used to detect the wavelength offset value of the target optical signal;

[0153] A wavelength change calculation module, used to calculate the ratio between the wavelength offset value and the initial wavelength to obtain the wavelength change;

[0154] The temperature variation calculation module is used to calculate the temperature variation of the long-period fiber grating sensor according to the wavelength variation as the temperature variation of the intermediate joint of the cable; when the long-period fiber grating sensor is fixed, the temperature variation is positively correlated with the wavelength variation.

[0155] In one embodiment of the present invention, the temperature variation is expressed as:

[0156]

[0157] Wherein, Δλ is the wavelength offset value, λ is the initial wavelength, α is the coefficient of variation between the grating pitch of the grating in the long period fiber grating sensor and the temperature, ε is the thermo-optic coefficient of the grating in the long period fiber grating sensor, and ΔT is the temperature variation.

[0158] The cable intermediate joint status detection device provided in the embodiment of the present invention can execute the cable intermediate joint status detection method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects for executing the cable intermediate joint status detection method.

[0159] Embodiment 3

[0160] See also Figure 4, showing a schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workbenches, personal digital assistants, blade servers, mainframe computers, and other suitable computers. The electronic device may also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0161] like Figure 4 As shown, the electronic device 10 includes at least one processor 11, and a memory connected to the at least one processor 11, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., wherein the memory stores a computer program that can be executed by at least one processor, and the processor 11 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or the computer program loaded from the storage unit 18 to the random access memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device 10 can also be stored. The processor 11, the ROM 12, and the RAM 13 are connected to each other through a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0162] A number of components in the electronic device 10 are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a disk, an optical disk, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0163] The processor 11 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 11 executes the various methods and processes described above, such as the state detection method of the cable intermediate joint.

[0164] In some embodiments, the state detection method of the cable intermediate joint can be implemented as a computer program, which is tangibly contained in a computer-readable storage medium, such as a storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed on the electronic device 10 via the ROM 12 and / or the communication unit 19. When the computer program is loaded into the RAM 13 and executed by the processor 11, one or more steps of the state detection method of the cable intermediate joint described above can be performed. Alternatively, in other embodiments, the processor 11 can be configured to execute the state detection method of the cable intermediate joint by any other appropriate means (for example, by means of firmware).

[0165] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0166] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when the computer program is executed by the processor, the functions / operations specified in the flow chart and / or block diagram are implemented. The computer program may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0167] In the context of the present invention, a computer-readable storage medium may be a tangible medium that may contain or store a computer program for use by or in combination with an instruction execution system, device or equipment. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0168] To provide interaction with a user, the systems and techniques described herein may be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or trackball) through which the user can provide input to the electronic device. Other types of devices may also be used to provide interaction with the user; for example, the feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form (including acoustic input, voice input, or tactile input).

[0169] The systems and techniques described herein may be implemented in a computing system that includes backend components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes frontend components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0170] A computing system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The client and server relationship is generated by computer programs running on the corresponding computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system to solve the defects of difficult management and weak business scalability in traditional physical hosts and VPS services.

[0171] Embodiment 4

[0172] An embodiment of the present invention further provides a computer program product, which includes a computer program. When the computer program is executed by a processor, the method for detecting the state of an intermediate cable joint as provided in any embodiment of the present invention is implemented.

[0173] In the process of implementation, the computer program product can be written in one or more programming languages ​​or a combination thereof to perform the computer program code of the present invention, including object-oriented programming languages, such as Java, Smalltalk, C++, and conventional procedural programming languages, such as "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computer (for example, using an Internet service provider to connect through the Internet).

[0174] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0175] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for detecting the state of a cable intermediate joint, characterized in that: A broadband light source, a circulator, a fiber Bragg grating sensor and a long-period fiber Bragg grating sensor are provided in the cable intermediate joint. The method comprises: Controlling the broadband light source to emit an original optical signal, wherein the original optical signal is coupled into the fiber Bragg grating sensor through the circulator; Controlling the fiber Bragg grating sensor to reflect a target optical signal, wherein the target optical signal is coupled into the long-period fiber Bragg grating sensor through the circulator; The state of the cable intermediate joint is detected by detecting the long-period fiber grating sensor and / or the target optical signal.

2. The method according to claim 1, characterized in that The controlling the broadband light source to emit the original light signal comprises: Controlling the broadband light source to emit an original optical signal that meets the emission conditions; The emission conditions include a central wavelength of 1550nm, a loudness of 3dB, a bandwidth of 52nm, and a power of 0.2mW.

3. The method according to claim 2, characterized in that The controlling the fiber Bragg grating sensor to reflect the target light signal comprises: Control the fiber Bragg grating sensor to reflect a target light signal that meets a reflection condition; The reflection conditions include a central wavelength of 1550 nm, a loudness of 3 dB, a bandwidth of 0.138 nm, and a reflectivity of more than 90%.

4. The method according to claim 2, characterized in that: The long period fiber grating sensor is attached to the inner side of the cable trench cover plate above the cable intermediate joint.

5. The method according to any one of claims 1 to 4, characterized in that The method of detecting the state of the cable intermediate joint based on detecting the long period fiber grating sensor and / or the target optical signal comprises: The deformation distance when the grating in the long-period fiber grating sensor is deformed is detected; the deformation distance is the maximum distance between the state where the grating in the long-period fiber grating sensor is deformed and the initial state; Calculating the deflection of the grating in the long-period fiber grating sensor according to the deformation distance; Taking the inverse of the deflection as the first curvature of the grating in the long-period fiber grating sensor; Calculating a second curvature of the grating in the long-period fiber grating sensor according to the optical power of the target optical signal; the second curvature is positively correlated with the optical power; Whether the cable intermediate joint is damaged by external force is detected according to the difference between the first curvature and the second curvature.

6. The method according to claim 5, characterized in that The deflection is expressed as: Wherein, R is the deflection, a is the initial length of the grating in the long-period fiber grating sensor, and h is the deformation distance.

7. The method according to any one of claims 1 to 4, characterized in that The method of detecting the state of the cable intermediate joint based on detecting the long period fiber grating sensor and / or the target optical signal comprises: detecting an initial wavelength of the target optical signal; Detecting a wavelength offset value of the target optical signal; Calculating the ratio between the wavelength offset value and the initial wavelength to obtain a wavelength change; The temperature variation of the long period fiber grating sensor is calculated according to the wavelength variation as the temperature variation of the cable intermediate joint; under the condition that the long period fiber grating sensor is fixed, the temperature variation is positively correlated with the wavelength variation.

8. The method according to claim 7, characterized in that The temperature variation is expressed as: Wherein, Δλ is the wavelength offset value, λ is the initial wavelength, α is the coefficient of variation between the grating pitch of the grating in the long period fiber grating sensor and the temperature, ε is the thermo-optic coefficient of the grating in the long period fiber grating sensor, and ΔT is the temperature variation.

9. An electronic device, characterized in that: The electronic device comprises: at least one processor; and a memory communicatively connected to the at least one processor; wherein, The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the method for detecting the status of an intermediate cable joint according to any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method for detecting the state of a cable intermediate joint according to any one of claims 1 to 8 is implemented.

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