A GIS imaging and transmission system based on infrared fiber bundle

Abstract

The application discloses a GIS imaging and transmission system based on infrared optical fiber bundles. The system is provided with a front objective lens, a chalcogenide glass long-wave infrared optical fiber image transmission bundle, a rear relay lens and a non-cooled infrared detector along an optical path. The front objective lens is a far-focus all-germanium lens group, and a protection glass is coated with a diamond-like film, so that the infrared radiation inside the GIS can be collected and the acid corrosion can be resisted; the numerical aperture of the optical fiber image transmission bundle is 0.56, the single fiber is hexagonally packed, and the thermal image is isolated and transmitted to the outside of the equipment by means of insulation flexibility; the rear relay lens adopts a far-focus four-germanium lens, and the thermal image of the optical fiber end face is coupled to the target surface of the detector. The application realizes photoelectric isolation by means of the optical fiber, eliminates the strong electromagnetic interference of the GIS, and has reasonable power distribution of the two lens groups, high imaging quality, and convenience for processing, assembling and adjusting. The application can non-contact temperature measurement of the contacts inside the GIS, and solves the defects of SF6 leakage in the traditional temperature measurement, poor anti-interference of the infrared equipment, lens corrosion and the like.

Description

Technical Field

[0001] This invention relates to the field of temperature monitoring technology for power equipment, and specifically to a GIS imaging and transmission system based on infrared fiber optic bundles. Background Technology

[0002] Gas-insulated switchgear (GIS) is a core component of modern power distribution and transmission, and its operational reliability directly determines the safety and stability of the regional power grid.

[0003] The internal space of a GIS (Gas Insulated Switchgear) is confined and tightly sealed, resulting in poor heat dissipation. When the busbar carries a large current, it generates a significant amount of heat, which cannot dissipate quickly enough, causing the internal temperature to rise continuously. If this is not detected in time, it can lead to SF6 gas decomposition, decreased insulation performance, and even catastrophic equipment explosions and large-scale power outages. Therefore, real-time temperature monitoring of components such as contacts inside the GIS is of paramount importance.

[0004] Currently, GIS internal temperature monitoring technologies are mainly divided into two categories: contact and non-contact. Contact-type technologies require disassembly and installation, are prone to SF6 leakage, and the sensors are susceptible to interference from high voltage and high current, resulting in a short lifespan. In contrast, infrared thermometry technology, due to its advantages of being non-contact, requiring no disassembly, and having strong anti-interference capabilities, has become the mainstream development direction for GIS contact temperature measurement. Long-wave infrared imaging technology collects infrared radiation from the surface of the object being measured, enabling non-contact and intuitive temperature field monitoring.

[0005] However, the high-voltage discharge and strong current inside GIS equipment generate extremely strong alternating electromagnetic interference, making it difficult to directly deploy conventional optoelectronic integrated detection equipment such as infrared thermal imagers near the equipment. Conventional thermal imagers contain a large number of microelectronic circuits and semiconductor devices, which cannot guarantee the normal acquisition and transmission of image signals in a strong electromagnetic field environment. Summary of the Invention

[0006] The purpose of this invention is to provide a GIS imaging and transmission system based on infrared fiber bundles to solve the problems of electromagnetic interference and acid corrosion that occur when conventional infrared thermal imagers are used for internal temperature monitoring of GIS.

[0007] To achieve the objectives of this invention, the technical solution provided by this invention is as follows: A GIS imaging and transmission system based on infrared fiber bundle, with a working wavelength of 8-12μm, includes, in sequence along the infrared radiation transmission direction, a front objective lens, a long-wave infrared fiber image transmission bundle, a rear relay lens, and an uncooled infrared detector. The front-end objective lens adopts an image-side telecentric structure to collect infrared radiation from the temperature-to-be-measured area inside the GIS and image the infrared radiation onto the incident end face of the long-wave infrared fiber optic image transmission bundle. The long-wave infrared fiber optic image bundle is made of chalcogenide glass with a numerical aperture of 0.56 and a single core diameter of 50 μm. The fiber filaments inside the end face adopt a hexagonal close-packed structure for spatial transmission of the infrared thermal distribution image of the front objective lens on the incident end face. The rear relay lens adopts an object-side telecentric structure to image the infrared thermal distribution image on the output end face of the long-wave infrared fiber optic image bundle onto the target surface of the uncooled infrared detector.

[0008] Furthermore, the front objective lens includes, in sequence along the incident direction of light, a protective glass, a first lens, a second lens, a third lens, and a fourth lens; the protective glass, the first lens, the second lens, the third lens, and the fourth lens are all made of germanium.

[0009] Furthermore, the focal length f1 of the first lens and the focal length f of the front objective lens are... a Satisfies the relation: 2 < |f1 / f a |<3.

[0010] Furthermore, the focal length f2 of the second lens and the focal length f of the front objective lens are... a Satisfies the relation: 2 < |f² / f a |<3; The focal length f3 of the third lens and the focal length f of the front objective lens a Satisfying the relation: 100 < |f³ / f a |<120; The focal length f4 of the fourth lens and the focal length f of the front objective lens a Satisfies the relation: 1 < |f4 / f a |<2.

[0011] Furthermore, the first surface of the protective glass facing the interior of the GIS is coated with a diamond-like carbon film, which is used to protect against acidic corrosive substances generated during the operation of the GIS.

[0012] Furthermore, the rear relay lens includes a fifth lens, a sixth lens, a seventh lens, and an eighth lens in sequence along the light incident direction; the fifth lens, the sixth lens, the seventh lens, and the eighth lens are all made of germanium.

[0013] Furthermore, the focal length f5 of the fifth lens and the focal length f of the rear relay lens are... b The following relationship is satisfied: 0.3 < |f5 / f b |<0.6.

[0014] Furthermore, the focal length f6 of the sixth lens and the focal length f of the rear relay lens are... b Relationship satisfied: 25 < |f6 / f b |<35; Furthermore, the focal length f7 of the seventh lens and the focal length f of the rear relay lens are... b The relation is satisfied: 0.3 < |f7 / f b |<0.6.

[0015] Furthermore, the focal length f8 of the eighth lens and the focal length f of the rear relay lens are... b The following relationship is satisfied: 0.3 < |f8 / f b |<0.6.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention is based on long-wave infrared image transmission beam technology using chalcogenide glass. With its excellent flexible transmission capability and complete electrical insulation properties, it uses a long-wave infrared fiber optic image transmission beam to guide the thermal distribution image of the internal contacts to a detector located outside the GIS equipment, thus solving the electromagnetic interference problem faced by conventional infrared thermal imagers when deployed directly. The system includes protective glass coated with a diamond-like carbon film, which can effectively protect against corrosion from acidic substances generated during the operation of the GIS. Attached Figure Description

[0017] Figure 1 This is an overall system diagram according to an embodiment of the present invention; Figure 2 This is a front objective lens diagram according to an embodiment of the present invention; Figure 3 This is a diagram of the back-end relay camera in an embodiment of the present invention; Figure 4 This is the MTF diagram of the front objective lens in an embodiment of the present invention; Figure 5 This is a point array diagram of the front objective lens according to an embodiment of the present invention; Figure 6 This is the MTF diagram of the back-end relay lens in an embodiment of the present invention; Figure 7 This is a point diagram of the back-end relay lens in an embodiment of the present invention.

[0018] In the diagram, 100 is the front objective lens; 101 is the long-wave infrared fiber optic image bundle; 102 is the rear relay lens; 103 is the uncooled infrared detector; STO is the aperture; I1 is the incident end face of the long-wave infrared fiber optic image bundle; E1 is the exit end face of the long-wave infrared fiber optic image bundle; A1 is the protective glass; L1 is the first lens; L2 is the second lens; L3 is the third lens; L4 is the fourth lens; L5 is the fifth lens; L6 is the sixth lens; L7 is the seventh lens; and L8 is the eighth lens. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0021] like Figure 1 As shown, this invention provides a GIS imaging and transmission system based on an infrared fiber optic bundle. The imaging system operates in the 8-12μm wavelength band and, along the infrared radiation transmission direction, sequentially includes: a front objective lens 100, a long-wave infrared fiber optic image transmission bundle 101, a rear relay lens 102, and an uncooled infrared detector 103; the front objective lens 100 is used to collect GIS images. The infrared radiation from the internal temperature-to-be-measured area is imaged onto the incident end face I1 of the long-wave infrared fiber optic image transmission bundle; the front objective lens 100 adopts an image-side telecentric structure; the long-wave infrared fiber optic image transmission bundle 101 is made of chalcogenide glass and is used for spatial transmission of the infrared thermal distribution image image formed by the front objective lens 100 on the incident end face I1 of the long-wave infrared fiber optic image transmission bundle; the numerical aperture of the long-wave infrared fiber optic image transmission bundle 101 is 0.56, the single core diameter is 50μm, and the fiber filaments inside the end face adopt a hexagonal close-packed structure; the rear relay lens 102 is used to image the infrared thermal distribution image on the exit end face E1 of the long-wave infrared fiber optic image transmission bundle onto the target surface of the uncooled infrared detector 103; the rear relay lens 102 adopts an object-side telecentric structure.

[0022] In this embodiment, as Figure 2 As shown, the front objective lens 100 includes, in sequence along the light incident direction: a protective glass A1, a first lens L1, a second lens L2, a third lens L3, and a fourth lens L4; the protective glass A1, the first lens L1, the second lens L2, the third lens L3, and the fourth lens L4 are all made of germanium. In this embodiment, the front objective lens 100 achieves the following optical specifications: (1) Focal length: EFFL = 6.8mm (2) F number = 1.18 (3) Linear field of view ≥ Ф120mm (4) Optical distortion: ≤2.1% (5) Operating spectral range: 8um~12um (6) Total optical length TTL≤32mm In this embodiment, the optical structure of the front objective lens 100 is characterized by: setting the focal length to f. a The focal lengths of the optical lenses from the first lens L1 to the fourth lens L4 are f1-f4 respectively; the two have the following relationship: 2<|f1 / f a |<3;2<|f2 / f a |<3;100<|f3 / f a |<120;1<|f4 / f a |<2 The protective glass A1 of this optical structure is located between the object plane and the first lens L1.

[0023] In this embodiment, the lens parameters of the front objective lens 100 are shown in Table 1 below. In Table 1, S1~S9 are the optical surfaces that the light passes through in sequence in the direction of light propagation; the protective glass A1 corresponds to surfaces S1 and S2, the first lens L1 corresponds to surfaces S3 and S4, the second lens L2 corresponds to surfaces S5 and S6, S7 is the aperture stop, the third lens L3 corresponds to surfaces S8 and S9, and the fourth lens L4 corresponds to surfaces S10 and S11.

[0024] Table 1

[0025] In this embodiment, by Figure 4 It can be seen that the front objective lens 100 has high resolution and its MTF curve is close to the diffraction limit; Figure 5 The black circle in the figure represents the Airy disk area. As can be seen from the figure, the point array of each field of view is smaller than the Airy disk. L1-L4 adopts an image-side telecentric structure with an F number of 1.18, which meets the coupling requirements of the long-wave infrared fiber optic image transmission bundle 101. It should be noted that this structure consists of four lenses with a reasonable distribution of optical power. The sensitivity of each optical component is reduced by adjusting the curvature and thickness, making the lens easier to process and adjust.

[0026] In this embodiment, as Figure 3 As shown, the rear relay lens 102 includes, in sequence along the light incident direction, a fifth lens L5, a sixth lens L6, a seventh lens L7, and an eighth lens L8; the materials of the fifth lens L5, the sixth lens L6, the seventh lens L7, and the eighth lens L8 are all germanium; In this embodiment, the back-end relay lens 102 achieves the following optical specifications: (1) Focal length: EFFL = 26mm (2) F number = 2.05 (3) Magnification: 1.69 (4) Optical distortion: ≤0.6% (5) Operating spectral range: 8um~12um (6) Total optical length TTL≤39mm In this embodiment, the optical structure of the rear relay lens 102 is characterized by: setting the focal length to f. b The focal lengths of the optical lenses from the first lens L5 to the fourth lens L8 are f1-f4 respectively; the relationship between them is as follows: 0.3 < |f5 / f b |<0.6;25<|f6 / f b |<35;0.3<|f7 / f b |<0.6; 0.3<|f8 / f b |<0.6 In this embodiment, the lens parameters of the rear relay lens 102 are shown in Table 2 below. In Table 2, S12~S17 are the optical surfaces that the light passes through in sequence in the direction of light propagation; the fifth lens L5 corresponds to surfaces S12 and S13, the sixth lens L6 corresponds to surfaces S14 and S15, the seventh lens L7 corresponds to surfaces S16 and S17, and the eighth lens L8 corresponds to surfaces S18 and S19.

[0027] Table 2

[0028] In this embodiment, by Figure 6 It can be seen that the back-end relay lens 102 has high resolution and its MTF curve is close to the diffraction limit. Figure 7 The black circle in the figure represents the Airy disk area. As can be seen from the figure, the point array of each field of view is smaller than the Airy disk. L5-L8 adopts an object-side telecentric structure with an F number of 2.05, which meets the coupling requirements of the long-wave infrared fiber optic image bundle 101. It should be noted that this structure consists of four lenses with a reasonable distribution of optical power; by adjusting the curvature and thickness, the sensitivity of each optical component is reduced, making the lens easier to manufacture and adjust.

[0029] Finally, it should be noted that the above embodiments are merely illustrative and explanatory of the present invention, and are not intended to limit the present invention to the scope of the described embodiments. Furthermore, those skilled in the art will understand that the present invention is not limited to the above embodiments, and many more variations and modifications can be made based on the teachings of the present invention, all of which fall within the scope of protection claimed by the present invention.

Claims

1. A GIS imaging and transmission system based on infrared fiber bundles, operating in the 8-12μm wavelength band, characterized in that, Along the infrared radiation transmission direction, it includes a front objective lens (100), a long-wave infrared fiber optic image transmission bundle (101), a rear relay lens (102), and an uncooled infrared detector (103). The front objective lens (100) adopts an image-side telecentric structure to collect infrared radiation from the temperature-to-be-measured area inside the GIS and image the infrared radiation onto the incident end face (I1) of the long-wave infrared fiber optic image transmission bundle. The long-wave infrared fiber image bundle (101) is made of chalcogenide glass with a numerical aperture of 0.56 and a single core diameter of 50 μm. The fiber filaments inside the end face adopt a hexagonal close-packed structure for spatial transmission of the infrared thermal distribution image of the front objective lens (100) on the incident end face. The rear relay lens (102) adopts an object-side telecentric structure and is used to image the infrared thermal distribution image on the output end face (E1) of the long-wave infrared fiber image transmission bundle onto the target surface of the uncooled infrared detector (103).

2. The GIS imaging and transmission system based on infrared fiber bundles according to claim 1, characterized in that, The front objective lens (100) includes, in sequence along the incident direction of light, a protective glass (A1), a first lens (L1), a second lens (L2), a third lens (L3), and a fourth lens (L4); the protective glass (A1), the first lens (L1), the second lens (L2), the third lens (L3), and the fourth lens (L4) are all made of germanium.

3. The GIS imaging and transmission system based on infrared fiber bundles according to claim 2, characterized in that, The focal length f1 of the first lens (L1) and the focal length f of the front objective lens (100) a Satisfies the relation: 2 < |f1 / f a |<3.

4. The GIS imaging and transmission system based on infrared fiber bundles according to claim 3, characterized in that, The focal length f2 of the second lens (L2) and the focal length f of the front objective lens (100) a Satisfies the relation: 2 < |f² / f a |<3; The focal length f3 of the third lens (L3) and the focal length f of the front objective lens (100) a Satisfying the relation: 100 < |f³ / f a |<120; The focal length f4 of the fourth lens (L4) and the focal length f of the front objective lens (100) a Satisfies the relation: 1 < |f4 / f a |<2.

5. The GIS imaging and transmission system based on infrared fiber bundles according to claim 4, characterized in that, The protective glass (A1) has a diamond-like carbon film coated on its first surface facing the interior of the GIS. This diamond-like carbon film is used to protect against acidic corrosive substances generated during the operation of the GIS.

6. The GIS imaging and transmission system based on infrared fiber bundles according to claim 5, characterized in that, The rear relay lens (102) includes a fifth lens (L5), a sixth lens (L6), a seventh lens (L7), and an eighth lens (L8) in sequence along the light incident direction; the fifth lens (L5), the sixth lens (L6), the seventh lens (L7), and the eighth lens (L8) are all made of germanium.

7. The GIS imaging and transmission system based on infrared fiber bundles according to claim 6, characterized in that, The focal length f5 of the fifth lens (L5) and the focal length f of the rear relay lens (102) b The following relationship is satisfied: 0.3 < |f5 / f b |<0.

6.

8. The GIS imaging and transmission system based on infrared fiber bundles according to claim 7, characterized in that, The focal length f6 of the sixth lens (L6) and the focal length f of the rear relay lens (102) b Relationship satisfied: 25 < |f6 / f b |<35.

9. The GIS imaging and transmission system based on infrared fiber bundles according to claim 8, characterized in that, The focal length f7 of the seventh lens (L7) and the focal length f7 of the rear relay lens (102) b The relation is satisfied: 0.3 < |f7 / f b |<0.

6.

10. The GIS imaging and transmission system based on infrared fiber bundles according to claim 9, characterized in that, The focal length f8 of the eighth lens (L8) and the focal length f of the rear relay lens (102) b The following relationship is satisfied: 0.3 < |f8 / f b |<0.6.

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