Optical fiber gas sensing device, method and cable joint partial discharge determination system

Abstract

The application relates to an optical fiber gas sensing device, a method and a cable joint partial discharge judgment system, wherein the optical fiber gas sensing device comprises: an oscillation module for performing oscillation frequency selection processing on optical signals of different wavelengths to obtain target bandwidth optical signals; an optical intensity detection module connected with the oscillation module, used for obtaining the light wave intensity change amount of the target bandwidth optical signals after the target bandwidth optical signals in a sensing gas chamber contact with the collected target gas from a cable joint; and a judgment module connected with the detection module, used for judging that the cable joint is in a partial discharge fault state when the light wave intensity change amount is equal to or greater than a preset partial discharge fault change amount. Thus, the optical fiber gas sensing device realizes rapid detection of the partial discharge fault of the cable joint, effectively improves the operation reliability of the cable joint, ensures the normal state of the power equipment, and further guarantees the power supply reliability of the power system.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of cable partial discharge detection, in particular to a kind of optical fiber gas sensing device, method and cable joint partial discharge determination system. BACKGROUND

[0002] With the continuous improvement of smart grid level, the requirement of power system power supply reliability is improved, and the state of power equipment directly determines the operation reliability of power system. As the power transport hub in power equipment, cable directly determines whether the state of power equipment is normal.

[0003] However, cable joint, as one of the most weak components in cable system and the component with high power grid failure, often occurs partial discharge failure. The existing cable joint lacks effective and online state monitoring means, and cannot find the deteriorated state in early failure. SUMMARY

[0004] Therefore, in view of the above problems, it is necessary to provide an optical fiber gas sensing device, method and cable joint partial discharge determination system.

[0005] In order to achieve the purpose of the present application, the technical scheme adopted by the present application is as follows:

[0006] An optical fiber gas sensing device comprises:

[0007] An oscillation module is used for oscillation frequency selection processing of light signals of different wavelengths to obtain target bandwidth light signals;

[0008] An optical intensity detection module is connected with the oscillation module, and is used for obtaining the change amount of optical wave intensity of the target bandwidth light signals after the target bandwidth light signals in the sensing gas chamber contact with the collected gas to be measured from the cable joint;

[0009] A determination module is connected with the detection module, and is used for determining that the cable joint is in a partial discharge failure state when the change amount of optical wave intensity is equal to or greater than a preset partial discharge failure change amount.

[0010] In one of the embodiments, the oscillation module comprises:

[0011] An oscillation unit is used for constructing a resonant cavity and forming laser oscillation based on the resonant cavity and light signals of different wavelengths to obtain light signals after the laser oscillation;

[0012] A filtering unit is connected with the oscillation unit, and is used for filtering processing of the light signals after the laser oscillation to obtain the target bandwidth light signals.

[0013] In one of the embodiments, the oscillation unit comprises:

[0014] The optical fiber is based on the mask plate in a preset area to generate a plurality of identical grating regions to construct the resonant cavity.

[0015] In one embodiment, the filter unit comprises:

[0016] The optical signal filter and the optical signal coupler are connected by fusion.

[0017] In one embodiment, the system further comprises:

[0018] The light source adjustment module is configured to adjust the light source to output the light signals of different wavelengths according to different characteristics of the gas to be measured.

[0019] In one embodiment, the system further comprises:

[0020] The demodulation module is configured to demodulate the light signals of different wavelengths output by the light source to generate the demodulated light signals.

[0021] The display module is connected to the demodulation module and configured to display the demodulated light signals.

[0022] A cable joint partial discharge determination system comprises:

[0023] A sensing chamber;

[0024] The oscillation module, the light intensity detection module, and the determination module are all arranged in the sensing chamber and connected to the cable joint through the sensing chamber.

[0025] In one embodiment, the sensing chamber is installed above the cable joint in the radial direction of the cable joint stress cone.

[0026] In one embodiment, the sensing chamber is made of organic polymer materials.

[0027] An optical fiber gas sensing method comprises:

[0028] The light signals of different wavelengths are subjected to oscillation frequency selection processing to obtain target bandwidth light signals.

[0029] When the target bandwidth light signals in the sensing chamber contact the gas to be measured collected from the cable joint, the light wave intensity variation of the target bandwidth light signals after the contact is obtained.

[0030] When the light wave intensity variation is equal to or greater than a preset partial discharge fault variation, it is determined that the cable joint is in a partial discharge fault state.

[0031] The optical fiber gas sensing device, the method and the cable joint partial discharge determination system, wherein the optical fiber gas sensing device comprises: an oscillation module for performing oscillation frequency selection processing on optical signals of different wavelengths to obtain target bandwidth optical signals; an optical intensity detection module connected with the oscillation module, for obtaining a change in optical wave intensity of the target bandwidth optical signals after the target bandwidth optical signals in a sensing gas chamber contact with the collected gas to be measured from the cable joint; and a determination module connected with the detection module, for determining that the cable joint is in a partial discharge fault state when the change in optical wave intensity is equal to or greater than a preset partial discharge fault change. Thus, the optical fiber gas sensing device realizes rapid detection of partial discharge faults of the cable joint, effectively improves the operation reliability of the cable joint, ensures the normal state of the power equipment, and further ensures the power supply reliability of the power system. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 A structural schematic diagram of the optical fiber gas sensing device in an embodiment is shown in FIG. 1.

[0033] Figure 2 A specific structural schematic diagram of the oscillation module in an embodiment is shown in FIG. 2.

[0034] Figure 3 A structural schematic diagram of the optical fiber gas sensing device in an embodiment is shown in FIG. 3.

[0035] Figure 4 A structural schematic diagram of the optical fiber gas sensing device in an embodiment is shown in FIG. 4.

[0036] Figure 5 A structural schematic diagram of the optical fiber gas sensing system in an embodiment is shown in FIG. 5.

[0037] Figure 6 An installation position schematic diagram of the sensing gas chamber in the cable accessory in an embodiment is shown in FIG. 6.

[0038] Figure 7 A flowchart of the optical fiber gas sensing method in an embodiment is shown in FIG. 7. DETAILED DESCRIPTION

[0039] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the accompanying drawings. The preferred embodiments of the present application are shown in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0041] It should be noted that when one element is considered to be "connected" to another element, it can be directly connected to the other element or connected to the other element through an intermediary element. Furthermore, in the following embodiments, "connection" should be understood as "electrical connection," "communication connection," etc., if there is transmission of electrical signals or data between the connected objects.

[0042] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising,” “including,” or “having,” etc., specify the presence of the stated feature, whole, step, operation, component, part, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof.

[0043] See Figure 1 This is a schematic block diagram of the structure of an optical fiber gas sensing device in one embodiment.

[0044] In this embodiment, as Figure 1 As shown, the fiber optic gas sensing device includes an oscillation module 120, a light intensity detection module 140, and a determination module 160.

[0045] The oscillation module 120 is used to perform oscillation frequency selection processing on optical signals of different wavelengths to obtain the target bandwidth optical signal.

[0046] The light intensity detection module 140 is connected to the oscillation module 120 and is used to obtain the change in light intensity of the target bandwidth light signal after contact when the target bandwidth light signal in the sensing chamber comes into contact with the gas to be tested collected from the cable connector.

[0047] The determination module 160, connected to the light intensity detection module 140, is used to determine that the cable joint is in a partial discharge fault state when the change in light intensity is equal to or greater than a preset partial discharge fault change.

[0048] The oscillation module 120 can be a functional unit in the fiber optic gas sensing device that generates laser oscillations for light signals of different wavelengths and performs optical filtering; the light intensity detection module 140 can be a functional unit in the fiber optic gas sensing device that detects changes in light intensity; and the judgment module 160 can be a functional unit in the fiber optic gas sensing device that determines whether a cable joint is in a partial discharge fault state based on changes in light intensity.

[0049] The oscillation frequency selection processing includes laser oscillation processing and optical filtering processing; the target bandwidth optical signal can be an optical signal with an extremely narrow bandwidth after laser oscillation processing and optical filtering processing; the gas to be measured includes aldehyde gas released when a partial discharge fault occurs in the cable joint, and air when the cable joint is normal; the preset partial discharge fault change amount can be the change in the light intensity of the target bandwidth optical signal after the minimum identifiable concentration of aldehyde gas when a partial discharge fault occurs in the cable joint comes into contact with it. The partial discharge fault state can be that the cable joint is experiencing partial discharge and cannot operate normally.

[0050] It should be noted that when the change in light intensity of the target bandwidth optical signal after contact is equal to the preset change in partial discharge fault, the gas to be measured in the sensing chamber contains a very small amount of aldehyde gas released when a partial discharge fault occurs at the cable joint. When the change in light intensity of the target bandwidth optical signal after contact is greater than the preset change in partial discharge fault, the gas to be measured in the sensing chamber contains a larger amount of aldehyde gas released when a partial discharge fault occurs at the cable joint. The basic principle of trace gas sensing follows the Lambert-Beer law: when light signals of different wavelengths pass through a chamber containing the gas to be measured, the light intensity will attenuate. The transmitted light intensity can be expressed as:

[0051] I(v)=I0(v)·exp[-σ(v)cL]

[0052] In the formula, I0(v) is the incident light intensity, I(v) is the transmitted light intensity, v is the light signal frequency, σ(v) represents the absorption cross-section of the gas spectral line at frequency v, c is the gas molecule number density, and L is the interaction distance between the gas and light, i.e., the effective absorption optical path, in centimeters. When the effective absorption optical path of the gas to be measured is constant, the absorbance at a specific wavelength is directly proportional to the gas concentration. Therefore, by calibrating the relationship between absorbance and gas concentration, the concentration of the gas can be measured.

[0053] In this embodiment, the oscillation module 120 performs laser oscillation processing and optical filtering processing on optical signals of different wavelengths to obtain an optical signal with an extremely narrow bandwidth after laser oscillation processing and optical filtering processing; the light intensity detection module 140 obtains the change in light intensity of the target bandwidth optical signal after contact with the gas to be tested collected from the cable joint when the target bandwidth optical signal in the sensing chamber comes into contact with the gas to be tested collected from the cable joint; the determination module 160 determines that a partial discharge fault has occurred in the cable joint when the change in light intensity is equal to or greater than a preset partial discharge fault change amount. Thus, the fiber optic gas sensing device enables rapid detection of partial discharge faults in cable joints, effectively improving the operational reliability of cable joints, thereby ensuring the normal status of power equipment and ultimately guaranteeing the reliability of power supply to the power system.

[0054] See Figure 2 This is a schematic block diagram of the oscillation module in one embodiment.

[0055] In this embodiment, as Figure 2 As shown, the oscillation module includes an oscillation unit 220 and a filter unit 240.

[0056] The oscillation unit 220 is used to construct a resonant cavity and generate laser oscillation based on the resonant cavity and optical signals of different wavelengths to obtain the optical signal after laser oscillation.

[0057] The filtering unit 240 is connected to the oscillation unit 220 and is used to filter the optical signal after laser oscillation in order to obtain the target bandwidth optical signal.

[0058] The oscillation unit 220 includes an optical fiber and a mask. The optical fiber generates multiple identical grating regions within a preset area based on the mask to construct the resonant cavity. The filtering unit 240 includes an optical signal filter and an optical signal coupler. The optical signal filter and the optical signal coupler are connected by fusion splicing. On the one hand, by adopting the structural combination of the optical signal filter and the optical signal coupler, the signal-to-noise ratio of the optical fiber gas sensing device is improved. On the other hand, the insertion loss can be reduced by connecting them by fusion splicing.

[0059] The optical fiber can be a 3cm long doped fiber, and the photomask can be a phase mask. The preset region can be within a 3cm span; the resonant cavity can be a Fabry-Perot resonant cavity formed by multiple identical grating regions; the optical signal filter includes a bulk grating filter and a fiber grating filter. Specifically, the optical fiber model is SM-TSF-9 / 125, and this single-mode single-clad fiber is suitable for core pumping of 980nm optical signals.

[0060] Optionally, two identical gratings are fabricated within a 3cm span using a phase mask in the doped fiber. These two grating regions form a Fabry-Perot resonant cavity and emit an optical signal with an extremely narrow linewidth. The Fabry-Perot resonant cavity between the two gratings is etched away, allowing the gas to be measured to enter and thus affect the refractive index, thereby achieving the purpose of detecting the composition of the gas to be measured.

[0061] See Figure 3 This is a schematic block diagram of the structure of an optical fiber gas sensing device in one embodiment.

[0062] In this embodiment, as Figure 3 As shown, the fiber optic gas sensing device includes an oscillation module 320, a light intensity detection module 340, and a judgment module 360, as well as a light source adjustment module 380.

[0063] The oscillation module 320 is used to perform oscillation frequency selection processing on optical signals of different wavelengths to obtain the target bandwidth optical signal.

[0064] The light intensity detection module 340 is connected to the oscillation module 320 and is used to obtain the change in light intensity of the target bandwidth light signal after contact when the target bandwidth light signal in the sensing chamber comes into contact with the gas to be tested collected from the cable connector.

[0065] The determination module 360, connected to the light intensity detection module 340, is used to determine that the cable joint is in a partial discharge fault state when the change in light intensity is equal to or greater than a preset partial discharge fault change.

[0066] For a description of the oscillation module 320, light intensity detection module 340, and determination module 360 ​​in this embodiment, please refer to the appendix. Figure 1 and appendix Figure 1 The oscillation module 120, light intensity detection module 140 and determination module 160 in the corresponding embodiments are described in detail.

[0067] The light source adjustment module 380 is connected to the oscillation module 320 via a light source and is used to adjust the light signal of different wavelengths output by the light source according to the different characteristics of the gas to be tested.

[0068] The light source adjustment module 380 is a light source manager that adjusts the output power of the light source according to different gases to be measured, so that the light source generates light signals of different wavelengths. The light source can be a 980nm pump light source, under the action of the pump light source, the doped optical fiber can generate a broadband optical signal of 1.54~2μm.

[0069] Optionally, the light source adjustment module 380 can change the wavelength of the optical signal output by the doped fiber by adjusting the pump light power, and the control system can realize cyclic scanning of the optical signal in this band. When partial discharge occurs in the cable joint, aldehyde gas is generated. If this aldehyde gas can enter the sensing gas chamber, the intensity of the corresponding light wave will change. By scanning the change in light wave intensity, the released gas can be detected. By cyclically scanning optical signals of different wavelengths, accurate detection of aldehyde gas accompanying partial discharge in the cable joint can be achieved, thereby realizing rapid detection of partial discharge faults in the cable joint and effectively improving the operational reliability of the cable joint.

[0070] See Figure 4 This is a schematic block diagram of the structure of an optical fiber gas sensing device in one embodiment.

[0071] In this embodiment, as Figure 4 As shown, the fiber optic gas sensing device includes an oscillation module 420, a light intensity detection module 440, and a judgment module 460, as well as a demodulation module 430 and a display module 450.

[0072] The oscillation module 420 is used to perform oscillation frequency selection processing on optical signals of different wavelengths to obtain the target bandwidth optical signal.

[0073] The light intensity detection module 440, connected to the oscillation module 420, is used to obtain the change in light intensity of the target bandwidth light signal after contact when the target bandwidth light signal in the sensing chamber comes into contact with the gas to be tested collected from the cable connector.

[0074] The determination module 460, connected to the light intensity detection module 440, is used to determine that the cable joint is in a partial discharge fault state when the change in light intensity is equal to or greater than a preset partial discharge fault change.

[0075] For a description of the oscillation module 420, light intensity detection module 440, and determination module 460 in this embodiment, please refer to the appendix. Figure 1 and appendix Figure 1 The oscillation module 120, light intensity detection module 140 and determination module 160 in the corresponding embodiments are described in detail.

[0076] The demodulation module 430 is connected to the light source and the oscillation module 420, and is used to demodulate the light signals of different wavelengths output by the light source to generate the demodulated light signals.

[0077] Display module 450, connected to demodulation module 430, is used to display the demodulated optical signal.

[0078] The demodulation module 430 can be a Mach-Zehnder interferometer; the demodulation process can be splitting the optical signal into two collimated optical signals and transmitting them through different paths and media; the demodulated optical signal can be two collimated optical signals containing the phase information generated by the split optical signals passing through different paths and media; the display module 450 can be a display screen. In this embodiment, the demodulation module 430 and the display module 450 are used to detect the output optical signal of the light source so that the light source outputs an optical signal that meets the requirements of different wavelengths.

[0079] See Figure 5 This is a schematic block diagram of the structure of an optical fiber gas sensing system in one embodiment.

[0080] In this embodiment, as Figure 5 As shown, the fiber optic gas sensing system includes a light source, a wavelength division multiplexer 520, a gas sensing unit 540, a demodulation module 530, and a display module 550. The gas sensing unit is a combination of an oscillation module, a light intensity detection module, and a judgment module. The wavelength division multiplexer 520 can be a 980 / 1550nm wavelength division multiplexer. The light source, in conjunction with the wavelength division multiplexer 520, can combine a series of information-carrying optical signals of different wavelengths into a single beam for transmission along the doped optical fiber.

[0081] In one embodiment, this application also provides a partial discharge determination system for cable joints. This system includes a sensing chamber and the fiber optic gas sensing device described in the above embodiment. The oscillation module, light intensity detection module, and determination module are all housed within the sensing chamber and connected to the cable joint via the sensing chamber. Optionally, the sensing chamber may also be a hollow metal tube, collecting gas through vents.

[0082] In one embodiment, such as Figure 6 The diagram shows the installation location of the sensing chamber within the cable accessory. The sensing chamber encapsulates the oscillation module, light intensity detection module, and judgment module, and is installed radially above the cable joint stress cone.

[0083] In one embodiment, the sensing chamber is made of an organic polymer material—polyimide, which can solve the problems of excessive size, difficulty in coupling, and inability to miniaturize existing sensing chambers made of metal materials, thus expanding the application scenarios of miniaturized sensing chambers.

[0084] It should be noted that the sensing chamber is made of either metal or organic polymer material, depending on the application scenario. The division of the various modules in the fiber optic gas sensing device in the above embodiments is only for illustrative purposes. In other embodiments, the fiber optic gas sensing device can be divided into different modules as needed to complete all or part of the functions of the above-described fiber optic gas sensing device.

[0085] See Figure 7 This is a schematic diagram of the fiber optic gas sensing method in one embodiment.

[0086] In this embodiment, the fiber optic gas sensing method includes steps 702 to 706.

[0087] Step 702: Perform oscillation frequency selection processing on optical signals of different wavelengths to obtain the target bandwidth optical signal.

[0088] Step 704: When the target bandwidth optical signal in the sensing chamber comes into contact with the gas to be tested collected from the cable connector, the change in the light intensity of the target bandwidth optical signal after contact is obtained.

[0089] Step 706: When the change in light intensity is equal to or greater than the preset change in partial discharge fault, the cable joint is determined to be in a partial discharge fault state.

[0090] Each step in this implementation corresponds to Figure 1 Each execution module in the process specifically participates in... Figure 1 China and Figure 1 The relevant descriptions in the corresponding embodiments are not repeated here.

[0091] Optionally, the fiber optic gas sensing method further includes:

[0092] The light source is adjusted to output light signals of different wavelengths according to the different properties of the gas to be tested.

[0093] Optionally, the fiber optic gas sensing method further includes:

[0094] The light signals of different wavelengths output by the light source are demodulated to generate the demodulated light signals, and the demodulated light signals are displayed.

[0095] The fiber optic gas sensing method provided in this embodiment obtains a target bandwidth optical signal by performing oscillation frequency selection processing on optical signals of different wavelengths. When the target bandwidth optical signal in the sensing chamber comes into contact with the gas to be tested collected from the cable joint, the change in the light intensity of the target bandwidth optical signal after contact is obtained. When the change in light intensity is equal to or greater than a preset partial discharge fault change, the cable joint is determined to be in a partial discharge fault state. Thus, the fiber optic gas sensing device enables rapid detection of partial discharge faults in cable joints, effectively improving the operational reliability of cable joints, thereby ensuring the normal operation of power equipment and ultimately guaranteeing the reliability of power supply from the power system.

[0096] It should be understood that, although Figure 7The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order suggested by the arrows. Unless otherwise specified in this document, there is no strict order in which these steps are performed; they can be executed in other orders. Figure 7 At least some of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but may be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but may be executed in turn or alternately with other steps or at least a portion of the sub-steps or stages of other steps. It should be noted that the different embodiments described above can be combined with each other.

[0097] In one embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to perform the following steps:

[0098] Oscillation frequency selection processing is performed on optical signals of different wavelengths to obtain the target bandwidth optical signal;

[0099] When the target bandwidth optical signal in the sensing chamber comes into contact with the gas to be tested collected from the cable connector, the change in the light intensity of the target bandwidth optical signal after contact is obtained.

[0100] When the change in light intensity is equal to or greater than the preset change in partial discharge fault, the cable joint is determined to be in a partial discharge fault state.

[0101] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, the computer program performing the following steps when executed by a processor:

[0102] Oscillation frequency selection processing is performed on optical signals of different wavelengths to obtain the target bandwidth optical signal;

[0103] When the target bandwidth optical signal in the sensing chamber comes into contact with the gas to be tested collected from the cable connector, the change in the light intensity of the target bandwidth optical signal after contact is obtained.

[0104] When the change in light intensity is equal to or greater than the preset change in partial discharge fault, the cable joint is determined to be in a partial discharge fault state.

[0105] In the description of this specification, the references to terms such as "some embodiments," "other embodiments," "ideal embodiments," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example that are included in at least one embodiment or example of this application. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0106] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0107] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A fiber optic gas sensing device, characterized in that, include: The oscillation module is used to perform oscillation frequency selection processing on optical signals of different wavelengths to obtain the target bandwidth optical signal; A light intensity detection module, connected to the oscillation module, is used to obtain the change in light intensity of the target bandwidth light signal after contact when the target bandwidth light signal in the sensing chamber comes into contact with the gas to be tested collected from the cable connector. The determination module, connected to the light intensity detection module, is used to determine that the cable joint is in a partial discharge fault state when the change in light intensity is equal to or greater than a preset partial discharge fault change. The oscillation module includes: An oscillation unit is used to construct a resonant cavity and generate laser oscillation based on the resonant cavity and optical signals of different wavelengths to obtain the optical signal after laser oscillation. A filtering unit, connected to the oscillation unit, is used to filter the optical signal after laser oscillation to obtain the target bandwidth optical signal.

2. The fiber optic gas sensing device according to claim 1, characterized in that, The oscillation unit includes: An optical fiber and a photomask are used to construct the resonant cavity by generating multiple identical grating regions within a predetermined area based on the photomask.

3. The fiber optic gas sensing device according to claim 1, characterized in that, The filtering unit includes: An optical signal filter and an optical signal coupler are provided, wherein the optical signal filter and the optical signal coupler are connected by a fusion splice.

4. The fiber optic gas sensing device according to any one of claims 1-3, characterized in that, Also includes: The light source adjustment module is used to adjust the light signal output of the light source at different wavelengths according to the different characteristics of the gas to be tested.

5. The fiber optic gas sensing device according to any one of claims 1-3, characterized in that, Also includes: The demodulation module is used to demodulate the light signals of different wavelengths output by the light source to generate the demodulated light signals. The display module is connected to the demodulation module and is used to display the demodulated optical signal.

6. A partial discharge detection system for cable joints, characterized in that, include: Sensing chamber; In the fiber optic gas sensing device according to any one of claims 1-5, the oscillation module, the light intensity detection module, and the determination module are all disposed in the sensing gas chamber and connected to the cable connector through the sensing gas chamber.

7. The cable joint partial discharge determination system according to claim 6, characterized in that, The sensing chamber is installed radially above the cable joint stress cone.

8. The cable joint partial discharge determination system according to claim 6, characterized in that, The sensing chamber is made of organic polymer materials.

9. A fiber optic gas sensing method, characterized in that, include: Oscillation frequency selection processing is performed on optical signals of different wavelengths to obtain the target bandwidth optical signal; When the target bandwidth optical signal in the sensing chamber comes into contact with the gas to be tested collected from the cable connector, the change in the light intensity of the target bandwidth optical signal after contact is obtained. When the change in light intensity is equal to or greater than the preset change in partial discharge fault, the cable joint is determined to be in a partial discharge fault state. The process of performing oscillation frequency selection on optical signals of different wavelengths to obtain a target bandwidth optical signal includes: forming laser oscillation based on a resonant cavity and optical signals of different wavelengths to obtain the optical signal after laser oscillation. The optical signal after laser oscillation is filtered to obtain the target bandwidth optical signal.

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