Insulator protective shell

Abstract

The present invention provides an insulator protective shell, which belongs to the technical field of power equipment, and includes a main shell corresponding to the shape of a pot-type insulator, the main shell being provided with a voltage-equalizing cylinder corresponding to the pot-type insulator voltage-equalizing ring of the pot-type insulator, the voltage-equalizing cylinder being provided with a protective shell voltage-equalizing ring, and the voltage-equalizing ring of the protective shell being provided with a connecting hole. The main shell and the voltage-equalizing cylinder are made as one piece. The main shell, the voltage-equalizing cylinder and the voltage-equalizing ring of the protective shell are all made of polytetrafluoroethylene material. The present invention can reduce the adhesion of metal particles on its surface, reduce the number of surface flashovers of the pot-type insulator caused by the adhesion of metal particles, extend the service life of the equipment, and during the maintenance process, the replacement is convenient and quick, and there is no need to remove it from the flange like the pot-type insulator.

Description

Technical Field

[0001] The present invention relates to the technical field of power equipment, and in particular to a pot-type insulator protective shell for GIS / GIL. Background Art

[0002] Gas-insulated switchgear / transmission line (GIS / GIL) boasts high transmission capacity, low power loss, compact structure, and high reliability, making it a preferred alternative to cables and overhead lines in specialized environments (such as hydropower transmission, mountain and river crossings, and underground pipelines). As voltage levels continue to rise, GIS usage is expanding, and GIL lengths are also increasing year by year. GIS / GIL, with its advantages of small footprint and strong resistance to electromagnetic interference, has gained widespread application in power systems. Insulators are a key component of GIS / GIL.

[0003] However, during the production, transportation, and equipment operation of GIS and GIL, metal particle contaminants are inevitably generated. Due to the diverse geometric shapes of metal particle contaminants, they can easily cause electric field distortion, leading to partial discharge and even insulation accidents. Metal particles can also reduce the insulation performance of the GIS / GIL system, especially near pot insulators. Metal particle contaminants adhere to the surface of the pot insulator, causing charge accumulation on the surface of the insulator. The presence of surface charge provides seed charge for surface flashover of the insulator, thereby increasing the probability of surface flashover. As a result, insulators become the weakest link and decisive factor in the overall insulation of the system in most cases, posing a great threat to the stable operation of the equipment. Traditional epoxy resin insulators are easily affected by the adhesion of metal particles, which leads to a reduction in their surface flashover performance. This is also an important reason for threatening the safe and stable operation of GIS / GIL. Summary of the Invention

[0004] The object of the present invention is to provide a pot-type insulator protective shell for GIS / GIL, so as to solve at least one technical problem existing in the above-mentioned background technology.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] On the one hand, the present invention provides an insulator protective shell, comprising: a main shell corresponding to the shape of a pot-type insulator, the main shell being provided with a voltage-equalizing cylinder corresponding to the pot-type insulator voltage-equalizing ring of the pot-type insulator, a protective shell voltage-equalizing ring being provided in the voltage-equalizing cylinder, and a connecting hole being provided on the protective shell voltage-equalizing ring.

[0007] Preferably, the main shell and the pressure equalizing cylinder are made in one piece.

[0008] Preferably, the main shell, the pressure equalizing cylinder, and the protective shell pressure equalizing ring are all made of polytetrafluoroethylene.

[0009] The beneficial effects of the present invention are as follows: the adhesion of metal particles on the surface thereof can be reduced, the number of surface flashovers of the basin-type insulator caused by the adhesion of metal particles can be reduced, the service life of the equipment can be extended, and during the maintenance process, replacement is convenient and quick, and there is no need to remove the basin-type insulator from the flange like the basin-type insulator.

[0010] Additional aspects and advantages of the present invention will be set forth in part in the following description, will become apparent from the following description, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0012] Figure 1 Schematic diagram of the relationship between the average surface flashover voltage and particle size of the material described in the embodiment of the present invention.

[0013] Figure 2 This is a cross-sectional structural diagram of the protective shell in the installation state without a cavity according to an embodiment of the present invention.

[0014] Figure 3 This is a three-dimensional structural diagram of the protective shell in the installation state without a cavity according to an embodiment of the present invention.

[0015] Figure 4 This is a cross-sectional structural diagram of the protective shell with a cavity installed in an embodiment of the present invention.

[0016] Figure 5 This is a three-dimensional structural diagram of the protective shell with a cavity installed in an embodiment of the present invention.

[0017] Figure 6 This is a schematic diagram of a surface flashover test platform constructed according to an embodiment of the present invention.

[0018] Among them: 1-main shell; 2-equalizing cylinder; 3-protective shell equalizing ring; 4-connecting hole; 5-pot insulator equalizing ring; 6-pot insulator; 7-cavity; 8-connecting flange. DETAILED DESCRIPTION

[0019] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention and are not to be construed as limiting the present invention.

[0020] Those skilled in the art will understand that unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art to which this invention belongs.

[0021] It should also be understood that terms, such as those defined in commonly used dictionaries, should be understood to have a meaning consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless as defined herein.

[0022] Those skilled in the art will appreciate that, unless otherwise stated, the singular forms "a," "an," "said," and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present invention refers to the presence of the stated features, integers, steps, operations, elements, and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, and / or groups thereof.

[0023] In the description of this specification, reference to the terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine and integrate different embodiments or examples described in this specification, as well as features of different embodiments or examples, unless otherwise inconsistent.

[0024] In the description of this specification, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0025] In the description of this specification, the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings. They are only for the convenience of describing the present technology and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, they should not be understood as limiting the present technology.

[0026] Unless otherwise specified or limited, the terms "installed," "connected," "connected," and "disposed" should be understood broadly. For example, they may refer to fixed connection or disposition, detachable connection or disposition, or integral connection or disposition. Those skilled in the art will understand the specific meanings of these terms in this technology based on specific circumstances.

[0027] To facilitate understanding of the present invention, the present invention is further explained below with reference to specific embodiments in conjunction with the accompanying drawings. However, the specific embodiments do not constitute a limitation on the embodiments of the present invention.

[0028] Those skilled in the art should understand that the drawings are merely schematic diagrams of embodiments, and the components in the drawings are not necessarily necessary for implementing the present invention.

[0029] Example

[0030] The surface properties of epoxy resin insulators are easily affected by the adhesion of metal particles. Therefore, selecting an insulating material with better surface properties to replace the epoxy resin interface can effectively suppress metal particle contamination in GIS / GIL. In addition to epoxy resin, there are many composite materials that can be used as insulating materials. Among them, polytetrafluoroethylene (PTFE) is one of the commonly used insulating materials. It has strong chemical stability and is known as the "King of Plastics". In addition, it has the advantages of non-stickiness, non-toxicity, and extremely strong electrical insulation properties. Through experimental research, it was found that PTFE shows certain advantages in terms of charge accumulation and the impact on flashover voltage. Based on this, this embodiment proposes a pot-type insulator protective shell for GIS / GIL to protect the pot-type insulator from the influence of metal particle adhesion.

[0031] In this embodiment, a comparative experiment was first conducted on the surface properties of epoxy resin and polytetrafluoroethylene materials, and experiments on insulator adhesion characteristics, surface flashover characteristics, and interface flashover performance were conducted respectively.

[0032] Insulator adhesion characteristics:

[0033] The adhesion force between metal particles and the insulator surface is the key factor affecting the adhesion of metal particles, and the magnitude of the adhesion force depends on the surface energy parameters of the insulator material.

[0034] Therefore, the contact angle method was used in this experiment to obtain the surface energy parameters of the two types of insulators. The surface energy parameters of the epoxy resin insulator are shown in Table 1. In order to obtain the surface energy of the PTFE insulator, a sample with a size of 50mm×50mm×5mm was prepared, and the contact angle measurement of different test liquids on the surface of the PTFE sample was carried out at room temperature (25°C). According to the surface energy component parameters of the different test liquids shown in Table 1, the surface energy and surface energy component parameters of PTFE were calculated as shown in Table 1. Compared with the surface energy of epoxy resin, it can be seen that the surface energy of PTFE is smaller and non-sticky, so metal particles are not easy to adhere to its surface. In Table 1, γ represents the surface energy, and the surface energy is composed of the Lifshitz van der Waals component γ LW and Lewis acid-base component γ AB Composition. Among them γ AB Contains Lewis acid component γ + and Lewis base component γ - ; γ L is the surface energy of the liquid (surface tension).

[0035] Table 1 Surface energy of PTFE and its components (mJ / m 2 )

[0036]

[0037] Surface flashover characteristics experiment:

[0038] Build as Figure 6 The surface flashover test platform shown in the figure. Before the test, a circular epoxy resin sample with a diameter of 5 cm and a thickness of 5 cm and a square PTFE sample with a size of 5 cm × 5 cm × 5 mm were prepared. Aluminum powders of 50 mesh, 150 mesh, 250 mesh, and 500 mesh were evenly attached to a 6 mm × 6 mm area in the center of the sample using the natural adhesion method.

[0039] The dust-attached sample to be tested is placed on the fingertip electrode tray, with the electrodes at both ends 1mm away from the edge of the dust-attached area, and there is no gap contact between the dust-attached sample and the bottom of the electrode. At the beginning of the test, an AC voltage of industrial frequency is applied to both ends of the fingertip electrodes, and the pressure speed is controlled to be 0.1-0.2kV / s. The pressure is continuously applied until the sample flashes along the surface, and the pressure is stopped and the voltage value is recorded. Five groups of experiments are repeated on the same dust-attached sample, and the average value of the five groups of values is taken as the final surface flashover voltage of the sample. The relationship between the dust particle size and the surface flashover voltage of the two materials is obtained, as shown below: Figure 1 shown.

[0040] Analysis of the experimental results shows that the surface flashover voltage of both materials increases with increasing particle size. However, when the diameter of the metal particles is large, the surface flashover voltage of polytetrafluoroethylene is slightly lower than that of epoxy resin, and the two values are similar. Therefore, the surface flashover characteristics of the two materials are similar.

[0041] Interface flashover performance experiment:

[0042] Based on the shape of the pot insulator, a PTFE shell was manufactured and installed on it to limit the surface flashover voltage of the pot insulator. After actual production and installation, it was found that a gap would form between the shell and the insulator surface, so it was necessary to measure whether the gap between the two would cause flashover.

[0043] A piece of metal particle was fixed on the surface of a pot-type insulator made of epoxy resin, and a breakdown test was carried out without a protective shell. The surface flashover voltage at the time of breakdown was recorded. Metal particles of the same size and length were fixed at the same position on the same type of pot-type insulator, and a PTFE material protective shell was installed on the outside of the pot-type insulator. A breakdown test was carried out and the flashover voltage at the time of breakdown was recorded.

[0044] The breakdown voltages recorded across multiple sets of experiments were averaged, and the experimental results are shown in Table 2. The data show that installing a protective sleeve on the pot insulator did not reduce the flashover voltage on the pot insulator surface. Therefore, the protective sleeve is acceptable.

[0045] Table 2 Interface flashover breakdown voltage

[0046]

[0047] Based on the above experimental results, in order to reduce the probability of surface flashover of the basin insulator in the GIL / GIS due to the adhesion of metal particles, this embodiment provides a protective shell made of PTFE material to reduce the adhesion of metal particles in the equipment to its surface. The metal particle adhesion of the PTFE material is lower than that of epoxy resin.

[0048] like Figures 2 to 5 As shown, the protective shell of the pot-type insulator in GIL / GIS made of PTFE material includes the following structures: a main shell 1 corresponding to the shape of the pot-type insulator, the main shell 1 is provided with a grading tube 2 corresponding to the pot-type insulator grading ring 5 of the pot-type insulator 6, the grading tube 2 is provided with a protective shell grading ring 3, and the protective shell grading ring 3 is provided with a connecting hole 4.

[0049] In practical applications, the main shell 1 and the pressure equalizing cylinder 2 can be made into one piece.

[0050] The main shell 1 , the pressure equalizing cylinder 2 , and the protective shell pressure equalizing ring 3 are all made of polytetrafluoroethylene.

[0051] The protective shell will follow the outer surface shape of the pot insulator and fit closely with the pot insulator. Figures 2 to 3 As shown, when installed without a cavity, a blind hole corresponding to the connection hole 4 on the protective shell grading ring 3 is provided on the pot insulator grading ring 5, and the two are fixed together with the insulating ring to prevent the protective shell from generating a gap with the pot insulator due to external vibrations during the operation of the equipment. Figures 4 and 5 As shown, when installed with a cavity, the cavity 7 is connected to the pot insulator 6 through the connecting flange 8, and the main housing 1 is located in the cavity 7 and fits tightly with the pot insulator.

[0052] In this embodiment, the thickness of the main housing 1 of the protective shell is 20% of the actual thickness of the basin insulator. In actual applications, the thickness of the main housing 1 of the protective shell can be adjusted according to the actual project requirements. Installing the protective shell in GIS / GIL equipment will reduce the number of surface flashovers of the basin insulator caused by the adhesion of metal particles. Installing the protective shell will increase the service life of the equipment and make replacement of the protective shell more convenient during maintenance. It can be simply pulled out from the high-voltage guide rod 5, without having to be removed from the flange like the basin insulator.

[0053] Although the above describes the specific embodiments of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solutions disclosed in the present invention without the need for creative work should be included in the scope of protection of the present invention.

Claims

1. An insulator protective shell, characterized in that: include: A main shell (1) corresponding to the outer shape of a pot-type insulator, the main shell (1) being provided with a grading tube (2) corresponding to the pot-type insulator grading ring (5) of the pot-type insulator (6), a protective shell grading ring (3) being provided inside the grading tube (2), and a connecting hole (4) being provided on the protective shell grading ring (3); the main shell (1) and the grading tube (2) being integrally formed; the main shell (1), the grading tube (2), and the protective shell grading ring (3) being all made of polytetrafluoroethylene material.

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