GIL contact temperature in-situ distributed on-line monitoring device

Abstract

The invention discloses a GIL contact temperature in-situ distributed on-line monitoring device, and belongs to state monitoring and operation maintenance of high-voltage transmission equipment. Wherein the optical fiber temperature sensing units are respectively arranged at key parts in each contact in the GIL; the sensing optical fiber penetrates through each guide rod in the GIL and connects each optical fiber temperature sensing unit in series in sequence; and the demodulator is positioned outside the GIL and is connected with one end of the sensing optical fiber. According to the invention, in-situ, distributed, full-coverage and high-precision on-line monitoring of the operating temperature of each contact of the GIL can be realized, a metal shell of the GIL is prevented from being damaged, the cost is low, and the method is suitable for long-term stable operation in an ultra-high-voltage alternating-current and direct-current GIL system with a complex electromagnetic environment.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of high-voltage power transmission equipment state monitoring and operation maintenance, and in particular to a GIL contact temperature in-situ distributed online monitoring device. BACKGROUND

[0002] Gas insulated metal enclosed transmission line (GIL) is widely used in long-distance and key power transmission scenarios due to its high-voltage, large-current carrying capacity, excellent insulation performance and good electromagnetic shielding characteristics. In GIL, in order to ensure the reliability and safety of power transmission, the operation state monitoring of the contact connection becomes a key link. The contact is prone to contact deterioration due to contact pressure attenuation, butt angle deviation, thermal cycle aging and other reasons during long-term operation, which may cause local overheating and induce gas decomposition, reduced insulation performance, and even short circuit accidents.

[0003] At present, the academic and engineering circles have carried out research on various high-voltage switchgear contact temperature monitoring technologies, including non-contact temperature measurement based on infrared imaging, online measurement of thermocouples or resistance temperature sensors, wireless sensor terminal sensing system, fiber Bragg grating (FBG) temperature measurement technology, and distributed optical fiber temperature measurement technology. Among them, optical fiber grating gradually becomes the preferred technology for temperature monitoring due to its small size, small electromagnetic interference, good insulation, and suitability for long-distance multi-point measurement.

[0004] For example, the document "Development of Wireless Sensing System for GIS Contact Overheating" proposes a wireless temperature measurement method, which uses a temperature sensing terminal to transmit the sensed temperature data to an external receiver through electromagnetic waves, realizing remote monitoring of GIS contact temperature. In addition, there are studies that try to infer the internal contact thermal state by establishing a multi-physical field simulation model combined with infrared spectrum and shell surface temperature difference.

[0005] However, most of these methods focus on switchgear (such as GIS), and there are still problems of insufficient adaptability for GIL system contact temperature monitoring with larger current and more stringent structure, especially the lack of mature solutions for structure without modification, in-situ distributed online monitoring.

[0006] The existing GIL contact temperature monitoring technologies mainly have the following shortcomings: (1) High requirement for structural modification, high risk of sealing. For example, the technology of embedding thermocouples or infrared probes requires opening holes on the GIL shell, changing its sealed structure, which may affect the sealing of the insulating gas and the electric field distribution of the equipment, with high manufacturing and operation cost and poor practicability.

[0007] (2) Wireless transmission is limited by the shielding effect of the metal shell. Some wireless sensing systems are difficult to achieve stable signal transmission due to the strong shielding effect of the GIL metal shell, and the system design requires extremely high stability and long-term reliability.

[0008] (3) Poor insulation reliability. The sensing signal of the thermocouple or resistance temperature sensor needs to be transmitted by metal wires. In the GIL temperature on-line measurement, the metal wires cannot be safely led from high potential to low potential, and the insulation strength of the wires is difficult to meet the requirements of GIL equipment, which can easily cause discharge accidents.

[0009] (4) The problems of electromagnetic interference and power supply have not been completely solved. For built-in electronic sensors, especially wireless or active devices, their power supply mode (such as battery or electromagnetic induction) and anti-interference ability are directly related to the stability of the system. Currently, there are still problems such as limited energy acquisition and frequent replacement of power supply. AC GIL can use alternating electromagnetic field for energy acquisition, but it is difficult to achieve for DC GIL.

[0010] (5) Lack of distributed, in-situ full-coverage measurement method. Most current solutions are single-point or few-point measurement, which cannot achieve touch temperature distribution monitoring on the entire length of GIL, especially for long-distance GIL systems. The state of multiple insulators cannot be fully understood, and there are monitoring blind spots. Infrared imaging or shell temperature measurement methods are indirect monitoring methods, which are greatly affected by heat conduction paths and heat dissipation factors. Especially in the early stage of overheating, the internal touch and the surface of the shell are in a thermal equilibrium process, and the internal temperature rise cannot be accurately reflected.

[0011] In summary, the existing technology still has significant technical gaps in realizing in-situ, distributed, on-line monitoring of touch temperature without damaging the GIL structure. SUMMARY

[0012] The present application aims to at least partially solve one of the technical problems in the related art. To this end, one object of the present application is to provide a GIL touch temperature in-situ distributed on-line monitoring device, which can realize in-situ, distributed, full-coverage, high-precision on-line monitoring of the operating temperature of each touch of GIL, avoid damaging the metal shell of GIL, have low cost, and be suitable for long-term stable operation in electromagnetic environment complex ultra-high voltage and extra-high voltage AC and DC GIL systems.

[0013] The GIL touch temperature in-situ distributed on-line monitoring device according to the embodiments of the present application comprises: optical fiber temperature sensing units arranged at the internal key positions of each touch inside the GIL; sensing optical fibers, which are threaded through each guide rod inside the GIL and sequentially connect each optical fiber temperature sensing unit. a demodulator located outside the GIL and connected to one end of the sensing optical fiber.

[0014] The working principle of the GIL contact temperature in-situ distributed online monitoring device is as follows: the demodulator emits a probe light, i.e., an incident signal, from a broadband light source, passes through an optical circulator, and injects the sensing optical fiber into the optical fiber temperature sensing unit. The reflected signal of the optical fiber temperature sensing unit is gathered back to the optical spectrum analyzer and the signal processing module for analysis, and the real-time temperature values of the key internal parts of each contact are output.

[0015] Compared with the prior art, the GIL contact temperature in-situ distributed online monitoring device can realize in-situ, distributed, full-coverage, and high-precision online monitoring of the operating temperature of each contact of the GIL, and has the following remarkable technical effects: I. In-situ multi-point distributed monitoring of contact temperature is realized, and the opening modification on the metal shell is avoided. In the embodiment of the application, a plurality of optical fiber temperature sensing units 1 are pre-buried at the key internal parts of each contact of the GIL, and are connected in series through a single sensing optical fiber, thereby realizing continuous temperature measurement of the contacts in the full length range of the GIL. Compared with the traditional thermocouple and infrared method which needs to open holes in the metal shell or can only obtain indirect temperature data, the embodiment of the application does not need to damage the structure and sealing of the metal shell, significantly improves the integrity and reliability of the monitoring, and has low cost.

[0016] II. Good anti-electromagnetic interference performance and high-voltage insulation capability, suitable for AC / DC systems. The sensing optical fiber is an insulating material and is not affected by the strong electric field and electromagnetic interference in the GIL, and is particularly suitable for long-term stable operation in the super and extra-high voltage AC and DC GIL systems with complex electromagnetic environment. The sensing signal is processed by the external demodulator, completely avoiding the common-mode interference that may be introduced by the electric signal acquisition, and improving the anti-interference performance and accuracy of the signal acquisition.

[0017] In summary, the embodiment of the application effectively solves the key technical problems of GIL contact temperature monitoring in terms of structure adaptation, signal acquisition, layout and wiring, and operation reliability, has remarkable technical advancement and engineering practical value, can be widely applied to newly built or modified high-voltage GIL power transmission projects, has good popularization prospect and social and economic benefits.

[0018] In some embodiments, the sensing optical fiber includes a pressure-resistant gas-tight optical fiber through connector penetrating through the optical fiber body arranged in each guide rod and the high-voltage electrode of the insulator fixed between adjacent guide rods; the two sides of the high-voltage electrode of each insulator are connected to the end portions of adjacent guide rods through the contacts, respectively; and each pressure-resistant gas-tight optical fiber through connector guides and connects the corresponding adjacent optical fiber bodies.

[0019] In some embodiments, the guide rod is a hollow guide rod, the end of the guide rod is inserted into the corresponding contact, and the fiber temperature sensing unit is arranged on the end of the guide rod.

[0020] In some embodiments, the inner periphery of the contact is provided with a protrusion, the end of the guide rod is in contact with the protrusion and fixed, and the fiber temperature sensing unit is arranged in the end of the guide rod and opposite to the protrusion.

[0021] In some embodiments, the fiber temperature sensing unit adopts a fiber grating array.

[0022] In some embodiments, the sensing optical fiber is a quartz optical fiber.

[0023] In some embodiments, the pressure-resistant and airtight optical fiber through connector comprises a through connector body, a light guide rod and an optical fiber joint, the through connector body is threadedly connected with the high-voltage electrode and airtightly connected, the light guide rod is arranged in the inside of the through connector body and airtightly connected with the through connector body, and the two ends of the light guide rod are respectively connected with the optical fiber joint and collimated with the optical fiber joint.

[0024] In some embodiments, the high-voltage electrode of the insulator is provided with an axial through hole; the axial through hole comprises a threaded hole and fixing holes located at both ends of the threaded hole; the hole diameter of the fixing hole is larger than that of the threaded hole, a shoulder is formed between the fixing hole and the threaded hole, the threaded hole is threadedly connected with the external thread of the through connector body, the fixing hole fixes the corresponding contact, and a sealing ring is arranged at the shoulder.

[0025] In some embodiments, the through connector body is provided with an operating part.

[0026] In some embodiments, an optical fiber insulation sleeve is further included, which is used to lead the sensing optical fiber from the high-potential conductor to the low-potential demodulator.

[0027] Additional aspects and advantages of the present application will be partially given in the following description, partially will become obvious from the following description, or will be understood by the practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a schematic diagram of a GIL contact temperature in-situ distributed online monitoring device according to an embodiment of the present application; Figure 2 is a structural schematic diagram of the application of a GIL contact temperature in-situ distributed online monitoring device according to an embodiment of the present application on a GIL; Figure 3 is a schematic diagram of a pressure-resistant and airtight optical fiber through connector in a GIL contact temperature in-situ distributed online monitoring device according to an embodiment of the present application. Figure 4 is a schematic view of an insulator in a GIL contact temperature in-situ distributed online monitoring device according to an embodiment of the present application; Figure 5 is a schematic view of a partial structure of a GIL contact temperature in-situ distributed online monitoring device according to an embodiment of the present application.

[0029] Reference signs Fiber temperature sensing unit 1; sensing fiber 2; fiber body 201; pressure-resistant airtight fiber through-connector 202; through-connector body 2021; external thread 20211; operating part 20212; fiber joint 2022; demodulator 3; broadband light source 301; optical circulator 302; optical spectrum analyzer 303; signal processing module 304; metal shell 4; guide rod 5; insulator 6; high-voltage electrode 601; axial through-hole 6011; threaded hole 60111; fixing hole 60112; sealing ring 602; fiber insulating sleeve 7; contact 8; protruding part 801. DETAILED DESCRIPTION

[0030] Embodiments of the present application are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0031] The GIL contact temperature in-situ distributed online monitoring device according to an embodiment of the present application is described below in conjunction with Figures 1 to 5 .

[0032] As shown in Figure 2 , Figures 4 to 5 , the GIL contact temperature in-situ distributed online monitoring device according to an embodiment of the present application is applied to a GIL to perform real-time online in-situ monitoring on the internal key parts of each contact 8 inside the GIL. The GIL includes a plurality of metal shells 4, a plurality of guide rods 5, and the plurality of guide rods 5 are coaxially arranged in the plurality of metal shells 4 one by one. The adjacent guide rods 5 and metal shells 4 are connected by an insulator 6 such as a pot-type insulator, so that a closed insulating gas chamber is formed inside each metal shell 4 (i.e., each metal shell 4 is filled with insulating gas). At the same time, the high-voltage electrode 601 of the insulator 6 such as the pot-type insulator between the adjacent guide rods 5 and metal shells 4 is fixed with a contact 8 on both sides, respectively. The contacts 8 fixed on both sides of the insulator 6 are connected to the end of the adjacent guide rod 5, specifically, by inserting the end of the guide rod 5 into the contact 8 and connecting and fixing with the contact 8.

[0033] As shown in Figures 1 to 2 and Figure 5As shown, the GIL contact temperature in-situ distributed online monitoring device of the embodiment of the present application comprises a fiber temperature sensing unit 1, a sensing fiber 2 and a demodulator 3.

[0034] Specifically, the fiber temperature sensing unit 1 is arranged at the internal key position of each contact 8 in the GIL, respectively, and the number of the fiber temperature sensing unit 1 arranged in a single contact 8 can be one or more according to actual needs. By arranging the fiber temperature sensing unit 1 at the internal key position of each contact 8, on the one hand, not only the local overheating point in-situ sensing of the internal key position of the contact 8 can be realized, but also the electric field and thermal field environment in the GIL metal shell 4 can be adapted to ensure the sensing accuracy and stability, on the other hand, arranging the fiber temperature sensing unit 1 at the internal key position of all contacts 8 in the GIL is conducive to realizing the in-situ, distributed, full-coverage and high-precision online real-time monitoring of the running temperature of the GIL contact 8.

[0035] The sensing fiber 2 penetrates through each guide rod 5 inside the GIL and connects the fiber temperature sensing units 1 in sequence. Thus, the sensing fiber 2 can transmit the signal, i.e. the optical signal, to each fiber temperature sensing unit 1 and gather the reflection signals of each fiber temperature sensing unit 1, which is conducive to realizing the continuous temperature measurement of all contacts 8 in the GIL; the sensing fiber 2 is made of insulating material and is not affected by the strong electric field and electromagnetic interference inside the GIL, and is particularly suitable for long-term stable operation in the electromagnetic environment of the super and extra-high voltage AC and DC GIL system; the sensing fiber 2 penetrates through each guide rod 5 inside, and no hole needs to be opened on the metal shell 4 of the GIL, and the structure and sealing of the metal shell 4 are not damaged, which significantly improves the integrity and reliability of the monitoring and reduces the manufacturing cost.

[0036] The demodulator 3 is located outside the GIL and connected with one end of the sensing fiber 2. The demodulator 3 can use the existing fiber grating demodulator, the incident signal is output to the fiber temperature sensing unit 1 through the sensing fiber 2, and the reflection signal of the fiber temperature sensing unit 1 is gathered to the demodulator 3 for processing through the sensing fiber 2, which completely avoids the common mode interference possibly introduced by the electric signal collection in the prior art, and improves the anti-interference and accuracy of the signal collection.

[0037] The working principle of the GIL contact temperature in-situ distributed online monitoring device of the embodiment of the present application is as follows: the demodulator 3 emits a probe light, i.e. an incident signal, from a broadband light source 301, the probe light passes through a light circulator 302 and is injected into the fiber temperature sensing unit 1 through the sensing fiber 2, the reflection signal of the fiber temperature sensing unit 1 is gathered and returned to the spectrum analyzer 303 and the signal processing module 304 for analysis, and the real-time temperature value of each internal key position of the contact 8 is output.

[0038] Compared with the prior art, the GIL contact temperature in-situ distributed online monitoring device of the embodiment of the application can realize in-situ, distributed, full-coverage and high-precision online monitoring of the operating temperature of each contact 8 of the GIL, and has the following remarkable technical effects: I. In-situ multi-point distributed monitoring of the temperature of the contact 8 is realized, and the opening modification on the metal shell 4 is avoided. In the embodiment of the application, a plurality of optical fiber temperature sensing units 1 are pre-buried at the internal key positions of each contact 8 of the GIL, and are connected in series through a single sensing optical fiber 2, so that continuous temperature measurement of the contact 8 in the full length range of the GIL is realized. Compared with the traditional thermocouple and infrared method which needs to open a hole in the metal shell 4 or can only obtain indirect temperature data, the embodiment of the application does not need to damage the structure and sealing of the metal shell 4, and significantly improves the integrity and reliability of the monitoring, and has low cost.

[0039] II. Good anti-electromagnetic interference performance and high-voltage insulation capability, suitable for AC / DC systems. The sensing optical fiber 2 is an insulating material and is not affected by the strong electric field and electromagnetic interference in the GIL, and is particularly suitable for long-term stable operation in super and extra-high voltage AC and DC GIL systems with complex electromagnetic environment. The sensing signal is processed by the external demodulator 3, completely avoiding the common-mode interference that may be introduced by the electric signal acquisition, and improving the anti-interference performance and accuracy of the signal acquisition.

[0040] In summary, the embodiment of the application effectively solves the key technical problems of the GIL contact 8 temperature monitoring in terms of structure adaptation, signal acquisition, layout and wiring and operation reliability, has remarkable technical advancement and engineering practical value, can be widely applied to newly built or modified high-voltage GIL power transmission projects, has good popularization prospect and social and economic benefits.

[0041] In some embodiments, as Figures 2 to 5As shown, the sensing optical fiber 2 includes a high-voltage-resistant airtight optical fiber through-piece 202 penetrating through the high-voltage electrode 601 of the insulator 6 fixed between adjacent guide rods 5 and the optical fiber body 201 penetrating through each guide rod 5. The two ends of the high-voltage-resistant airtight optical fiber through-piece 202 are respectively located in adjacent airtight insulating gas chambers with the same air pressure, and the air pressure difference on both sides of the through-piece is small. The high-voltage-resistant airtight optical fiber through-piece 202 itself has good airtightness and high-voltage resistance, which can ensure that the sensing optical fiber 2 penetrates through multiple airtight insulating gas chambers without affecting the sealing and insulation performance of the GIL, and avoids the leakage of the insulating gas in the GIL due to the opening on the GIL metal shell 4 caused by the pressure of the airtight insulating gas chamber being higher than the external pressure. The high-voltage electrode 601 of each insulator 6 is connected to the end of the adjacent guide rod 5 through the contact 8 on both sides, realizing the electrical connection between the guide rods 5. Each high-voltage-resistant airtight optical fiber through-piece 202 is optically connected to the corresponding adjacent optical fiber body 201, so that the sensing optical fiber 2 can transmit signals, that is, the incident signals are transmitted to each optical fiber temperature sensing unit 1, and the reflected signals of each optical fiber temperature sensing unit 1 are aggregated to the demodulator 3, which is conducive to realizing the continuous temperature measurement of all contacts 8 of the GIL.

[0042] In some embodiments, as shown in Figure 2 , Figure 5 The guide rod 5 is a hollow guide rod, so that the optical fiber body 201 penetrates through the guide rod 5. The end of the guide rod 5 is inserted into the corresponding contact 8, and the optical fiber temperature sensing unit 1 is arranged on the end of the guide rod 5, that is, the optical fiber temperature sensing unit 1 is arranged in the contact 8, and the arrangement of the optical fiber temperature sensing unit 1 is located in the key position inside the contact 8.

[0043] In some embodiments, as shown in Figure 5 The inner periphery of the contact 8 is provided with a protruding part 801, and the end of the guide rod 5 is in contact with and fixed to the protruding part 801. The optical fiber temperature sensing unit 1 is arranged in the end of the guide rod 5 and opposite to the protruding part 801, that is, the optical fiber temperature sensing unit 1 is arranged in the contact 8, and the arrangement of the optical fiber temperature sensing unit 1 is located in the key position inside the contact 8.

[0044] In some embodiments, as shown in Figure 1 and Figure 5 The optical fiber temperature sensing unit 1 adopts a fiber grating array, which has small volume, small electromagnetic interference and good insulation.

[0045] In some embodiments, the sensing optical fiber 2 is a quartz optical fiber, which has excellent transmission performance, longer transmission distance, faster speed and lower signal loss rate, is not affected by electromagnetic interference, and can better meet the signal transmission demand; the quartz optical fiber has stable material properties.

[0046] In some embodiments, as shown in Figure 3 andFigure 4 As shown, the pressure-resistant and airtight optical fiber through-connector 202 comprises a through-connector body 2021, a light guide rod (not shown in the figure) and an optical fiber joint 2022 (such as an optical fiber FC joint); the through-connector body 2021 is threadedly matched with the high-voltage electrode 601 and is airtightly connected, the light guide rod is arranged inside the through-connector body 2021 and is airtightly connected with the through-connector body 2021, and the two ends of the light guide rod are respectively connected with the optical fiber joint 2022 and are collimated with the optical fiber joint 2022.

[0047] The pressure-resistant and airtight optical fiber through-connector 202 is convenient to install, has good airtightness and high pressure bearing capacity, can ensure that the sensing optical fiber 2 penetrates through multiple closed and insulated air chambers without affecting the sealing and insulation performance of the GIL, has small signal loss and high transmission efficiency.

[0048] In some embodiments, as shown in Figure 3 and Figure 4 The high-voltage electrode 601 of the insulator 6 is provided with an axial through-hole 6011; the axial through-hole 6011 comprises a threaded hole 60111 and fixing holes 60112 located at both ends of the threaded hole 60111; the hole diameter of the fixing hole 60112 is larger than the hole diameter of the threaded hole 60111, a shoulder is formed between the fixing hole 60112 and the threaded hole 60111; the threaded hole 60111 is threadedly matched with the external thread 20211 of the through-connector body 2021, so that the insulator 6 and the pressure-resistant and airtight optical fiber through-connector 202 are convenient to install; the fixing hole 60112 fixes the corresponding contact 8, so that the insulator 6 and the contact 8 are convenient to install; a sealing ring 602 is arranged at the shoulder, so as to ensure the airtightness of the closed and insulated air chambers on both sides of the insulator 6.

[0049] In some embodiments, the through-connector body 2021 is provided with an operating portion 20212, so that the pressure-resistant and airtight optical fiber through-connector 202 is clamped at the operating portion 20212 by using an operating tool such as a wrench, and is installed in the threaded hole 60111 of the high-voltage electrode 601 of the insulator 6 through thread matching.

[0050] In some embodiments, as shown in Figure 2 The optical fiber insulation sleeve 7 is used to lead the sensing optical fiber 2 from the high-potential conductor to the low-potential demodulator 3.

[0051] Since the sensing optical fiber 2 runs inside the high-potential conductor inside the GIL, the optical fiber insulation sleeve 7 is used as a leading channel to safely lead the sensing optical fiber 2 from the high-potential conductor to the low-potential external demodulator 3, so as to ensure the creepage distance and the insulation level and avoid high-potential leakage to cause discharge or safety accidents. This design significantly improves the practicability and safety protection level of the GIL contact temperature in-situ distributed online monitoring device in actual engineering deployment.

[0052] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary and are not to be construed as limiting the present application, and that variations, modifications, substitutions and changes can be made by those skilled in the art without departing from the scope of the present application.

Claims

1. A distributed online monitoring device for GIL contact temperature in situ, characterized in that, include: Fiber optic temperature sensing units are respectively arranged in key parts inside each contact inside the GIL. The sensing fiber runs through each guide rod inside the GIL and connects each of the fiber temperature sensing units in series. A demodulator, located outside the GIL and connected to one end of the sensing optical fiber.

2. The in-situ distributed online monitoring device for GIL contact temperature according to claim 1, characterized in that, The sensing optical fiber includes an optical fiber body that runs through each of the guide rods and a pressure-resistant, airtight optical fiber connector that runs through a high-voltage electrode fixed between adjacent guide rods; the two sides of the high-voltage electrode of each insulator are respectively connected to the ends of the adjacent guide rods through the contacts; each pressure-resistant, airtight optical fiber connector guides light to the corresponding adjacent optical fiber body.

3. The in-situ distributed online monitoring device for GIL contact temperature according to claim 2, characterized in that, The guide rod is a hollow guide rod, and the end of the guide rod is inserted into the corresponding contact. The fiber optic temperature sensing unit is arranged on the end of the guide rod.

4. The in-situ distributed online monitoring device for GIL contact temperature according to claim 3, characterized in that, The inner circumference of the contact is provided with a protrusion, and the end of the guide rod is in contact with and fixed to the protrusion; the fiber optic temperature sensing unit is arranged inside the end of the guide rod and is directly opposite the protrusion.

5. The in-situ distributed online monitoring device for GIL contact temperature according to any one of claims 1-4, characterized in that, The fiber optic temperature sensing unit employs a fiber optic grating array.

6. The in-situ distributed online monitoring device for GIL contact temperature according to any one of claims 2-4, characterized in that, The sensing optical fiber is a quartz optical fiber.

7. The in-situ distributed online monitoring device for GIL contact temperature according to any one of claims 2-4, characterized in that, The pressure-resistant and airtight fiber optic connector includes a connector body, a light guide rod, and fiber optic connectors. The connector body is threaded and airtightly connected to the high-voltage electrode. The light guide rod is disposed inside the connector body and airtightly connected to the connector body. Both ends of the light guide rod are respectively connected to the fiber optic connectors and are collimated with the fiber optic connectors.

8. The in-situ distributed online monitoring device for GIL contact temperature according to claim 7, characterized in that, The high-voltage electrode of the insulator is provided with an axial through hole; the axial through hole includes a threaded hole and fixing holes located at both ends of the threaded hole; the diameter of the fixing hole is larger than the diameter of the threaded hole, a shoulder is formed between the fixing hole and the threaded hole, the threaded hole is threadedly engaged with the external thread of the through-hole body, the fixing hole fixes the corresponding contact, and a sealing ring is arranged at the shoulder.

9. The in-situ distributed online monitoring device for GIL contact temperature according to claim 8, characterized in that, The main body of the penetrator is equipped with an operating section.

10. The in-situ distributed online monitoring device for GIL contact temperature according to any one of claims 1-4, characterized in that, It also includes an optical fiber insulating sleeve, which is used to lead the sensing optical fiber from the high-potential conductor to the low-potential demodulator.

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