Optical fiber insulator and current measuring device

Abstract

The application relates to an optical fiber insulator and a current measuring device. The optical fiber insulator comprises an insulator, a flange, an optical fiber and a shielding cover, the insulator is a hollow structure; the flange is arranged at one end of the insulator and is nested with the insulator; the optical fiber is arranged in the insulator and the flange; the shielding cover is arranged on the outer surface of the optical fiber and is arranged in the insulator, and one end of the shielding cover is connected with the flange. By arranging the shielding cover on the outer surface of the optical fiber and connecting the shielding cover with the flange at one end of the insulator, the field intensity in the flange at the high-voltage end of the insulator is reduced to the maximum, the probability of discharge in the insulator is reduced, the optical fiber is protected from ablation caused by external discharge, signal transmission interruption caused by damage of the optical fiber is avoided, the reliability of optical fiber data transmission is improved, and the current measuring device can operate more safely and stably.

Description

Technical Field

[0001] This application relates to the field of ultra-high voltage direct current transmission technology, and in particular to an optical fiber insulator and a current measuring device. Background Technology

[0002] Optical current measuring devices utilize the Faraday magneto-optical effect, transmitting optical signals through optical fibers to measure the current being measured. They are widely used in ultra-high voltage direct current (UHVDC) transmission for detecting the magnitude of the transmission current. In UHVDC power stations, insulators serve as insulation and mechanical connections between high-voltage electrical equipment and the grounding electrode. Due to the influence of the high-voltage busbar, high-voltage equipment, other floating potential devices, and the impedance of the ground potential distribution within the power station, the electric field distribution of the insulators is extremely uneven. The electric field distortion on the high-voltage side of the insulator is severe, especially on the sheds near the flange and the surface of the insulator jacket, which experience electric field strengths several times higher than those in the central sheds. This can lead to phenomena such as internal insulator discharge, ablation, and optical fiber damage. Therefore, it is urgent to improve the reliability of insulators to ensure the safe and stable operation of current measuring devices in DC systems. Summary of the Invention

[0003] Therefore, it is necessary to provide a highly reliable, safe and stable optical fiber insulator and current measuring device to address the above-mentioned technical problems.

[0004] In a first aspect, this application proposes an optical fiber insulator, comprising: an insulator, a flange, an optical fiber, and a shielding cover, wherein the insulator is a hollow structure; the flange is disposed at one end of the insulator and nested within the insulator; the optical fiber passes through the insulator and the flange; the shielding cover is disposed on the outer surface of the optical fiber and is disposed inside the insulator, and one end of the shielding cover is connected to the flange.

[0005] In one embodiment, the other end of the shield is connected to an equalizing ring, which is sleeved on the optical fiber.

[0006] In one embodiment, the equalizing ring has a diameter of 5 mm.

[0007] In one embodiment, the mesh size of the shield is between 10 and 100 meshes.

[0008] In one embodiment, the shielding cover is made of titanium alloy.

[0009] In one embodiment, the wall thickness of the shield is 0.5 mm to 1 mm.

[0010] In one embodiment, the shield is configured as a cylinder.

[0011] In one embodiment, the maximum inner diameter of the shield is less than 1.05 times the outer diameter of the optical fiber.

[0012] Secondly, this application also proposes a current measuring device, comprising: an optical fiber current sensing ring, an optical fiber insulator, and a signal acquisition module, wherein the optical fiber current sensing ring is used to be sleeved on the conductor to be measured; the optical fiber insulator is connected to the optical fiber current sensing ring, and the optical fiber insulator includes the optical fiber insulator described in the first aspect embodiment above; the signal acquisition module is connected to the optical fiber insulator, and the signal acquisition module is used to obtain the current magnitude based on the modulated optical signal.

[0013] The aforementioned fiber optic insulator and current measuring device, by setting a shield on the outer surface of the optical fiber and connecting the shield to the flange at one end of the insulator, minimizes the field strength inside the high-voltage flange of the insulator, reduces the probability of internal discharge of the insulator, protects the optical fiber from external discharge erosion, avoids signal transmission interruption due to damage to the optical fiber, improves the reliability of optical fiber data transmission, and enables the current measuring device to operate more safely and stably. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the structure of an optical fiber insulator in one embodiment;

[0016] Figure 2 for Figure 1 A magnified view of a portion of point A in the middle;

[0017] Figure 3 This is a schematic diagram of a current measuring device module in one embodiment.

[0018] Explanation of reference numerals in the attached figures:

[0019] Insulator 110, flange 120, optical fiber 130, shielding cover 140, equalizing ring 150, optical fiber current sensing ring 210, optical fiber insulator 220, signal acquisition module 230. Detailed Implementation

[0020] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0021] 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 is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0022] It is understood that the terms “first,” “second,” etc., used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another.

[0023] Spatial relation terms such as “below,” “under,” “below,” “under,” “above,” “above,” etc., are used herein to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, the element or feature described as “below,” “under,” or “below” will be oriented “above” the other element or feature. Therefore, the exemplary terms “below” and “under” can include both above and below orientations. Furthermore, the device may also include other orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptive terms used herein will be interpreted accordingly.

[0024] 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.

[0025] 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 features, wholes, steps, operations, components, parts, or combinations 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. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0026] In one embodiment, such as Figure 1 and Figure 2 As shown, an optical fiber insulator is provided, including: an insulator 110, a flange 120, an optical fiber 130, and a shield 140. The insulator 110 has a hollow structure; the flange 120 is disposed at one end of the insulator 110 and nested with the insulator 110; the optical fiber 130 passes through the insulator 110 and the flange 120; the shield 140 is disposed on the outer surface of the optical fiber 130 and is disposed inside the insulator 110, with one end of the shield 140 connected to the flange 120.

[0027] Specifically, the insulator 110 can be configured as a post type or a suspension type. The insulator 110 used in power stations can be an all-ceramic post insulator, an all-ceramic core rod composite jacket insulator, a hollow sleeve composite jacket insulator, or an epoxy fiber core rod composite jacket insulator, which can be selected according to the needs of fiber optic data transmission and the signal transmission environment. The insulator 110 is a device installed between conductors at different potentials or between a conductor and a grounding component, capable of withstanding voltage and mechanical stress. It plays an important role in overhead transmission lines and converter stations. In this embodiment, the insulator 110 has a hollow structure, and the interior of the insulator 110 is used to pass through the optical fiber 130, providing support and protection for the optical fiber 130.

[0028] Flange 120 is made of metal and is located at one end of insulator 110, nested within insulator 110. It is used for connection between pipe ends; that is, one end of flange 120 is connected to insulator 110, and the other end is used for fixing to other components. It is understood that flange 120 has through holes, allowing bolts to be used to fix flange 120, thereby indirectly fixing insulator 110.

[0029] In this embodiment, the optical fiber 130 is a polarization-maintaining fiber. Polarization-maintaining fibers are used to transmit linearly polarized light. In interferometric fiber optic sensors based on optical coherence detection, using a polarization-maintaining fiber ensures that the linear polarization direction remains unchanged, improving the coherence signal-to-noise ratio and enabling high-precision measurement of physical quantities. Specifically, the Kerr effect induced by the transverse electric field in the polarization-maintaining fiber produces linear birefringence, and the Faraday effect induced by the longitudinal magnetic field in the polarization-maintaining fiber produces circular birefringence. By demodulating the modulated optical signal, the corresponding current magnitude can be obtained.

[0030] The shielding cover 140 is made of metal and covers the outer surface of the optical fiber 130, meaning the optical fiber 130 passes through the interior of the shielding cover 140. The shielding cover 140 is also located inside the insulator 110, specifically in the interlayer between the optical fiber 130 and the insulator 110. Simultaneously, due to the severe distortion of the electric field distribution on the high-voltage side of the insulator 110, the sheds near the flange 120 and the outer surface of the insulator 110 experience an electric field strength several times higher than that of the central sheds. Therefore, the shielding cover 140 needs to be connected to the flange 120, meaning it contacts the flange 120, to further protect the optical fiber at the connection between the flange 120 and the insulator 110, preventing internal discharge that could damage the optical fiber 130. Understandably, to ensure a tighter contact between the flange 120 and the shielding cover 140, the shielding cover 140 can extend beyond the end of the insulator 110 to connect with the flange 120. For example, when installing the flange 120 onto the insulator 110, one end of the shield 140 extends beyond the end of the insulator 110, then the flange 120 is pressed onto the shield 140, and finally fixed to the insulator 110, so that the flange 120 and the shield 140 can be in closer contact.

[0031] The aforementioned optical fiber insulator, by setting a shield 140 on the outer surface of the optical fiber 130 and connecting the shield 140 to the flange 120 at one end of the insulator 110, minimizes the field strength inside the high-voltage flange 120 of the insulator 110, reduces the probability of internal discharge of the insulator 110, protects the optical fiber 130 from external discharge erosion, avoids signal transmission interruption due to damage to the optical fiber 130, improves the reliability of optical fiber data transmission, and enables the current measuring device to operate more safely and stably.

[0032] In one embodiment, the other end of the shielding cover 140 is connected to an equalizing ring 150, which is sleeved on the optical fiber 130. Specifically, the equalizing ring 150 provides shielding against the electric field. It is understood that the shielding effect is better when the entire circumference of the equalizing ring 150 is connected to the shielding cover 140. The position of the equalizing ring 150 on the optical fiber 130 is related to the length of the shielding cover 140. Since the electric field strength is greater near the flange 120, the length of the shielding cover 140 can be slightly greater than the length of the flange 120 overlapping with the insulator 110 to achieve the purpose of protecting the optical fiber 130. In some other embodiments, the side of the shielding cover 140 away from the flange 120 can be rolled up to achieve the same purpose of protecting the optical fiber 130. The equalizing ring 150 can be made of copper, aluminum, or other metals with good conductivity.

[0033] In one embodiment, the diameter of the equalizing ring 150 is 5 mm. In this embodiment, the diameter of the equalizing ring 150 is set to 5 mm based on the inner diameter of the insulator 110 and the outer diameter of the optical fiber 130. In some other embodiments, the diameter of the equalizing ring 150 can be changed according to specific circumstances.

[0034] In one embodiment, the shielding cover 140 has a mesh count of 10 to 100 meshes. The shielding cover 140 in this embodiment is configured as a mesh structure, and a mesh count ranging from 10 to 100 meshes can achieve a good shielding effect. The mesh count is the number of mesh openings per inch (25.4 mm) of length. For example, the aperture of the mesh openings in a 100-mesh shielding mesh is approximately 0.15 mm.

[0035] In one embodiment, the shielding cover 140 is made of titanium alloy. Titanium alloy is a high-hardness, corrosion-resistant metal material that can protect the optical fiber 130 from ablation by external discharge, preventing damage to the internal optical fiber 130 and thus avoiding interruption of optical signal transmission.

[0036] In one embodiment, the wall thickness of the shield 140 is 0.5 mm to 1 mm. Specifically, the shield 140 can be made of titanium alloy mesh with a thickness of 0.5 mm to 1 mm, which can achieve a better electric field shielding effect.

[0037] In one embodiment, the shielding cover 140 is cylindrical. Specifically, in this embodiment, the optical fiber 130 is cylindrical. To ensure a tighter fit between the shielding cover 140 and the optical fiber 130, the shielding cover 140 is cylindrical, and the optical fiber 130 passes through the cylinder. In some other embodiments, when there are multiple optical fibers 130, the shielding cover 140 can be configured as a rectangular cylinder or similar shape, depending on the shape formed by the convergence of the optical fibers 130.

[0038] In one embodiment, the maximum inner diameter of the shielding cover 140 is less than 1.05 times the outer diameter of the optical fiber 130. Specifically, to ensure a tighter fit between the optical fiber 130 and the shielding cover 140, and to improve the protective effect of the shielding cover 140 on the optical fiber 130, the maximum inner diameter of the shielding cover 140 in this embodiment is less than 1.05 times the outer diameter of the optical fiber 130, ensuring that the shielding cover 140 fits tightly onto the optical fiber 130. In some other embodiments, the inner diameter of the shielding cover 140 can be changed as needed.

[0039] In one embodiment, insulator 110 is a composite insulator. Composite insulators are composed of glass fiber epoxy resin core rods and have advantages such as light weight, small size, not easy to break, and convenient transportation and installation. In particular, they have excellent resistance to pollution flashover and wet flashover, which can better support and protect optical fiber 130.

[0040] In one embodiment, such as Figure 3As shown, this application also proposes a current measuring device, including: an optical fiber current sensing ring 210, an optical fiber insulator 220, and a signal acquisition module 230. The optical fiber current sensing ring 210 is used to be sleeved on the conductor to be measured; the optical fiber insulator 220 is connected to the optical fiber current sensing ring 210, and the optical fiber insulator 220 includes the optical fiber insulator in the above embodiment; the signal acquisition module 230 is connected to the optical fiber insulator 220, and the signal acquisition module 230 is used to obtain the current magnitude according to the modulated optical signal.

[0041] Specifically, the fiber optic current sensing ring 210 is made of multiple turns of sensing fiber and is sleeved on the conductor under test. Its main function is to sense the measured current. The fiber optic insulator 220 connects to the fiber optic current sensing ring 210 and is used to transmit optical signal data. The fiber optic insulator 220 is the same as the fiber optic insulator described in the above embodiment, and will not be described in detail here. The signal acquisition module 230 mainly consists of two parts: an optical path unit and a signal processing circuit. The optical path unit includes optical components such as a light source, a modulator, and a photodetector. The optical path unit performs polarization and modulation processing on the optical signal generated by the light source and then sends it to the fiber optic current sensing ring 210. At the same time, the photodetector receives the modulated optical signal carrying current information returned by the fiber optic current sensing ring 210. After demodulation and calculation by the signal processing circuit, the current value can be obtained, thereby completing the measurement of the current on the conductor under test.

[0042] The aforementioned current measuring device, by setting a shield 140 on the outer surface of the optical fiber 130 and connecting the shield 140 to the flange 120 at one end of the insulator 110, minimizes the electric field strength inside the high-voltage flange 120 of the insulator 110, reduces the probability of internal discharge of the insulator 110, protects the optical fiber 130 from external discharge erosion, avoids signal transmission interruption due to damage to the optical fiber 130, improves the reliability of optical fiber data transmission, and enables the current measuring device to operate more safely and stably.

[0043] In the description of this specification, references to terms such as "one embodiment," "some embodiments," and "specific embodiment" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0044] 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.

[0045] 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 invention patent. 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. An optical fiber insulator, characterized in that, include: Insulator, wherein the insulator is a hollow structure; A flange, which is disposed at one end of the insulator and nested therewith; An optical fiber, which is a polarization-maintaining optical fiber, is inserted between the insulator and the flange. A shielding cover is disposed on the outer surface of the optical fiber and inside the insulator. One end of the shielding cover is connected to the flange, and the end of the shielding cover extending beyond the insulator is connected to the flange. The shielding cover is configured as a mesh structure.

2. The optical fiber insulator according to claim 1, characterized in that, The other end of the shield is connected to an equalizing ring, which is sleeved on the optical fiber.

3. The optical fiber insulator according to claim 2, characterized in that, The equalizing ring has a diameter of 5 mm.

4. The optical fiber insulator according to claim 1, characterized in that, The mesh size of the shielding cover is between 10 and 100 meshes.

5. The optical fiber insulator according to claim 1, characterized in that, The shielding cover is made of titanium alloy.

6. The optical fiber insulator according to claim 1, characterized in that, The shield has a wall thickness of 0.5 mm to 1 mm.

7. The optical fiber insulator according to claim 1, characterized in that, The shielding cover is cylindrical.

8. The optical fiber insulator according to claim 7, characterized in that, The maximum inner diameter of the shield is less than 1.05 times the outer diameter of the optical fiber.

9. The optical fiber insulator according to claim 1, characterized in that, The insulator is a composite insulator.

10. A current measuring device, characterized in that, include: An optical fiber current sensing ring is used to be fitted onto the conductor to be tested. An optical fiber insulator, wherein the optical fiber insulator is connected to the optical fiber current sensing ring, and the optical fiber insulator comprises the optical fiber insulator according to any one of claims 1 to 9; A signal acquisition module is connected to the optical fiber insulator and is used to obtain the current magnitude based on the modulated optical signal.

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