Current transformer and gas-insulated metal-enclosed switchgear

Abstract

The invention relates to a current transformer and a gas-insulated metal-enclosed switchgear. The current transformer comprises a first shell used for forming a cavity; the cavity is filled with insulating gas; the conductor passes through the cavity and penetrates through the first shell; the annular coil surrounds the first shell and is used for sensing current flowing through the conductor; and the protective cover and the first shell form a closed structure wrapping the annular coil. By adopting the method, the insulating property can be improved, the annular coil can be protected from being influenced by the outside, and stable operation of the current transformer is ensured.

Description

Technical Field

[0001] This application relates to the technical field of power equipment, and particularly to a current transformer and a gas-insulated metal-enclosed switchgear. Background Art

[0002] With the development of power equipment technology, a current transformer, a power equipment, has emerged, which can be used to measure the current of a power system and ensure the stable operation of the power system.

[0003] In traditional technologies, the coil for inducing current in a current transformer is generally arranged inside the housing of the current transformer. Since the current transformer generally uses SF6 gas insulation and the insulation performance of SF6 gas is extremely sensitive to the moisture content, and the moisture in the coil is extremely likely to exceed the standard. Therefore, the current transformer with this structure is extremely likely to discharge and has the problem of poor insulation performance. Summary of the Invention

[0004] Based on this, it is necessary to provide a current transformer and a gas-insulated metal-enclosed switchgear that can improve the insulation performance in view of the above technical problems.

[0005] In a first aspect, this application provides a current transformer, which includes:

[0006] A first housing for forming a cavity; an insulating gas is filled in the cavity;

[0007] A conductor passing through the cavity and penetrating the first housing;

[0008] A toroidal coil disposed around the first housing for inducing the current flowing through the conductor;

[0009] A protective cover forming a closed structure with the first housing to wrap the toroidal coil.

[0010] In one embodiment, the first housing is a cylinder, and the wound toroidal coil enters from the first end of the first housing and is disposed around the first housing; a support platform for fixing the toroidal coil is provided at the second end of the first housing;

[0011] The current transformer further includes a second housing, and the second housing is a cylinder;

[0012] The second housing is connected to the first housing at the first end of the first housing; the conductor passes through the cavity formed by the second housing and penetrates the second housing.

[0013] In one embodiment, the first housing is connected to the second housing through a transition flange.

[0014] In one embodiment, a first coupling flange is provided at a first end of the first housing; the first housing is coupled to the transition flange based on the first coupling flange.

[0015] In one embodiment, the current transformer further includes a pressure ring with a through hole, which is clamped on the first coupling flange; the pressure ring is coupled to the transition flange through bolts.

[0016] In one embodiment, the current transformer further includes an insulating partition; the insulating partition is disposed between the pressure ring and the transition flange.

[0017] In one embodiment, the first housing, the second housing, and the transition flange form a sealed cavity; the sealed cavity is filled with the insulating gas.

[0018] In one embodiment, a conductive sealing ring is provided between the protective cover and the support platform.

[0019] In one embodiment, the toroidal coil and the first housing are integrally bonded by epoxy resin glue.

[0020] In a second aspect, the present application further provides a gas-insulated metal-enclosed switchgear, including the current transformer in any of the above embodiments.

[0021] The above current transformer and gas-insulated metal-enclosed switchgear are configured to form a first housing for a cavity, and the cavity is filled with an insulating gas, which can ensure that the conductor passing through the cavity and penetrating the first housing is in an insulating environment. On the one hand, the toroidal coil configured to sense the current flowing through the conductor and surrounding the first housing can separate the toroidal coil of the induced current from the conductor. Even if the moisture in the toroidal coil exceeds the standard, it will not affect the insulation problem of the current transformer, improving the insulation performance of the current transformer; on the other hand, a protective cover is configured, and the protective cover and the first housing form a closed structure that wraps the toroidal coil, protecting the toroidal coil from being affected by the outside and ensuring the stable operation of the current transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following will briefly introduce the drawings required for describing the embodiments of the present application or related technologies. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0023] Figure 1 It is a structural block diagram of a current transformer in one embodiment;

[0024] Figure 2 It is a structural block diagram of a support platform in a current transformer in one embodiment;

[0025] Figure 3 It is a structural block diagram of a current transformer in another embodiment;

[0026] Figure 4 It is a structural block diagram of a current transformer in yet another embodiment;

[0027] Figure 5 It is a structural block diagram of a first connection flange in a current transformer in one embodiment;

[0028] Figure 6 It is a structural block diagram of a current transformer in still another embodiment;

[0029] Figure 7 It is a structural block diagram of a current transformer in still another embodiment;

[0030] Figure 8 It is a structural block diagram of a conductive sealing ring in a current transformer in one embodiment;

[0031] Figure 9 It is a structural block diagram of a bolt in a current transformer in one embodiment;

[0032] Figure 10 It is a structural block diagram of an annular coil in one embodiment;

[0033] Figure 11 It is a structural block diagram of a transition flange in one embodiment;

[0034] Figure 12 It is a structural block diagram of a connection flange in one embodiment;

[0035] Figure 13 It is a structural block diagram of a pressure ring in one embodiment.

[0036] Reference numerals: 10 - first housing; 20 - conductor; 30 - annular coil; 40 - protective cover; 50 - support platform; 60 - second housing; 70 - transition flange; 80 - first connection flange; 90 - pressure ring; 100 - insulating partition; 110 - conductive sealing ring; 120 - bolt; 130 - bolt insulating sheath; 140 - upper connection flange; 150 - lower connection flange. Detailed implementation manners

[0037] To facilitate the understanding of this application, the following will describe this application more comprehensively with reference to the relevant drawings. Embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of this application more thorough and comprehensive.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs. The terms used in the description of this application herein are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0039] Spatial relationship terms such as "under", "below", "lower", "beneath", "above", "upper", etc. can be used herein to describe the relationship of one element or feature shown in the figure with other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relationship terms also include different orientations of the device during use and operation. For example, if the device in the drawing is flipped, an element or feature described as "under other elements" or "beneath it" or "under it" will be oriented "above" other elements or features. Therefore, the exemplary terms "under" and "below" can include both upper and lower orientations. In addition, the device can also include other orientations (such as rotating 90 degrees or other orientations), and the spatial descriptive terms used herein are accordingly interpreted.

[0040] It should be noted that when an 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 intermediate element. In addition, in the following embodiments, "connection", if there is a transfer of electrical signals or data between the connected objects, should be understood as "electrical connection", "communication connection", etc.

[0041] As used herein, the singular forms "a", "an" and "the" may also include the plural forms unless the context clearly dictates otherwise. It should also be understood that the terms "comprise / include" or "have" etc. specify the presence of the stated features, wholes, steps, operations, components, parts or combinations thereof, but do not preclude the presence or addition of one or more other features, wholes, steps, operations, components, parts or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the related listed items.

[0042] As described in the background art, in the traditional technology, the coil used for sensing current in a current transformer is generally arranged inside the housing of the current transformer. Since the current transformer generally uses SF6 gas insulation, the insulation performance of SF6 gas is extremely sensitive to the moisture content, and the moisture in the coil is very likely to exceed the standard. Therefore, the current transformer with this structure is very likely to discharge and has the problem of poor insulation performance.

[0043] For the above reasons, as Figure 1As shown in the figure, the present application provides a current transformer for improving insulation performance, including: a first housing 10, which is used to form a cavity; an insulating gas is filled in the cavity; a conductor 20, which passes through the cavity and penetrates the first housing 10; a toroidal coil 30, which is disposed around the first housing 10 and is used to sense the current flowing through the conductor 20; a protective cover 40, which forms a closed structure with the first housing 10 to wrap the toroidal coil 30.

[0044] Among them, the housing refers to an external structure used to enclose, support, or protect internal components. The first housing 10 is the main structural component for forming the cavity, used to form and support the cavity, ensure its structural stability, and provide an installation basis for other components. The cavity is the internal space surrounded by the first housing 10, used to fill the insulating gas, isolate the conductor 20 from the external environment, and ensure electrical safety. Exemplarily, the shape and size of the cavity are designed according to specific application requirements and are usually a sealed structure.

[0045] The insulating gas refers to the gas filled in the cavity, which has high insulation performance, can prevent electrical breakdown, and improve the insulation strength of the device. For example, the insulating gas includes sulfur hexafluoride ( ), nitrogen ( ), etc. The conductor 20 refers to the electrical component that passes through the cavity and penetrates the first housing 10, which can be used to transmit current and connect circuits.

[0046] The toroidal coil 30 refers to the coil disposed around the first housing 10, which can sense the current flowing through the conductor 20 and is used for current measurement. In the present application, the toroidal coil 30 is wound around an iron core with enameled copper wire, and the iron core is laminated or wound with very thin silicon steel sheets.

[0047] The protective cover 40 is an external protection component that forms a closed structure with the first housing 10, which can protect the toroidal coil 30 from the influence of the external atmospheric environment and prevent mechanical damage and pollution.

[0048] Specifically, in the above current transformer, a first housing 10 configured to form a cavity is provided, and the cavity is filled with an insulating gas, which can ensure that the conductor 20 passing through the cavity and penetrating the first housing 10 is in an insulating environment. That is, the first housing 10 only needs to accommodate the conductor 20 and the insulating gas, and does not need to accommodate the toroidal coil 30. Compared with the existing current transformers, the diameter of the first housing 10 in this current transformer is smaller, and the material cost is significantly reduced. Moreover, a toroidal coil 30 configured to sense the current flowing through the conductor 20 and surrounding the first housing 10 is provided. Compared with the existing current transformers, the toroidal coil 30 is placed outside the first housing 10, and its moisture content has little impact on the insulation inside the product, improving the insulation reliability. In addition, it can also improve the convenience of installation and testing, is easy to maintain, and has low maintenance costs. A protective cover 40 is configured, and the protective cover 40 and the first housing 10 form a closed structure that wraps the toroidal coil 30, which can protect the internal structure of the current transformer. Moreover, through the reasonable setting of the protective cover 40, its environmental tolerance performance can also be improved.

[0049] For the above current transformer, a first housing 10 configured to form a cavity is provided, and the cavity is filled with an insulating gas, which can ensure that the conductor 20 passing through the cavity and penetrating the first housing 10 is in an insulating environment. On the one hand, a toroidal coil 30 configured to sense the current flowing through the conductor 20 and surrounding the first housing 10 is provided, which can separate the toroidal coil 30 for sensing the induced current from the conductor 20. Even if the moisture in the toroidal coil 30 exceeds the standard, it will not affect the insulation problem of the current transformer, improving the insulation performance of the current transformer; on the other hand, a protective cover 40 is configured, and the protective cover 40 and the first housing 10 form a closed structure that wraps the toroidal coil 30, protecting the toroidal coil 30 from being affected by the outside world and ensuring the stable operation of the current transformer.

[0050] In one embodiment, as Figure 2 shown, the first housing 10 is a cylinder, and the wound toroidal coil 30 enters from the first end of the first housing 10 and surrounds the first housing 10; a support platform 50 for fixing the toroidal coil 30 is provided at the second end of the first housing 10; as Figure 3 shown, the current transformer further includes a second housing 60, and the second housing 60 is a cylinder; the second housing 60 is connected to the first housing 10 at the first end of the first housing 10; the conductor 20 passes through the cavity formed by the second housing 60 and penetrates the second housing 60.

[0051] Among them, the main function of the support platform 50 is to ensure that the toroidal coil 30 can be stably placed and fixed. As Figure 2 shown, the first end of the first housing 10 is the upper end of the first housing 10, and the second end is the lower end of the first housing 10.

[0052] Specifically, the first housing 10 is a cylinder. After the first housing 10 is placed, the wound toroidal coil 30 can first enter from the first end of the first housing 10 and surround the first housing 10. After reaching the support platform 50 at the second end of the first housing 10, it is placed on the support platform 50. On this basis, the second housing 60 of the current transformer is connected to the first housing 10 at the first end of the first housing 10, and the conductor 20 passes through the cavity formed by the second housing 60 and penetrates the second housing 60. Among them, the second housing 60 is a cylinder. It can be understood that flanges are provided at the second end of the first housing 10 and the upper end of the second housing 60, which can enable the extended connection between the current transformer and external components.

[0053] Exemplarily, the first housing 10 can be a thin-walled cylinder with an inner diameter of 450 mm to 500 mm, a wall thickness of 6 mm to 10 mm, and is welded from aluminum. It has a connecting flange at the lower part for the extended connection between the current transformer and external components. It has a ring-shaped support platform 50 in the middle for placing the toroidal coil 30. The toroidal coil 30 and the first housing 10 are integrally bonded together with epoxy resin glue. The second housing 60 is a thin-walled cylinder with an inner diameter of 500 mm to 550 mm, a wall thickness of 6 mm to 10 mm, and is welded from aluminum.

[0054] In this embodiment, two housings are provided for the current transformer. Before the second housing 60 is sleeved on the first housing 10, the toroidal coil 30 is first sleeved on the first housing 10; the first housing 10 only needs to accommodate the conductor 20 and insulating gas, and does not need to accommodate the toroidal coil 30, so that the diameter of the housing is small and the material cost is significantly reduced.

[0055] In one embodiment, as Figure 4 shown, the first housing 10 is connected to the second housing 60 through a transition flange 70.

[0056] Among them, a flange is a circular or square disc-shaped component, usually used for detachable connections between pipelines, valves, equipment, etc. It has good sealing performance and pressure resistance, and is connected together with bolts, gaskets and another flange to achieve the docking or closure of pipelines, equipment, etc. The transition flange 70 is a special type of flange used to connect pipelines with different sizes, different pressure ratings or different connection methods. It usually consists of two ports, one end is connected to one type of pipeline, and the other end is connected to another type of pipeline with different sizes or different connection methods.

[0057] Specifically, in the present application, the transition flange 70 is made of aluminum plate or cast from aluminum material. Its thickness is 30 - 40 mm. It has two sets of staggered threads. The first housing 10 is connected to the second housing 60 through the transition flange 70, and the connection method between the first housing 10 and the second housing 60 through the transition flange 70 is bolt connection.

[0058] In one embodiment, as Figure 5 shown, the first end of the first housing 10 is provided with a first connection flange 80; the first housing 10 is connected to the transition flange 70 based on the first connection flange 80.

[0059] Among them, the connection flange is a flange for connection.

[0060] Specifically, the first end of the first housing 10 is further provided with a first connection flange 80. The first housing 10 is connected to the transition flange 70 based on the first connection flange 80 and then connected to the second housing 60, which can ensure the stability of the connection between the first housing 10 and the second housing 60.

[0061] In one embodiment, as Figure 6 shown, the current transformer further includes a pressure ring 90 with a through hole, which is clamped on the first connection flange 80; the pressure ring 90 is connected to the transition flange 70 through bolts.

[0062] Among them, the pressure ring 90 for clamping is a specially designed metal part, mainly used for connecting pipes and pipe fittings.

[0063] Specifically, the current transformer further includes a pressure ring 90 with a through hole, which is clamped on the first connection flange 80. The pressure ring 90 is connected to the transition flange 70 through bolts to connect the first housing 10 and the second housing 60, thereby improving the stability of the connection between the first housing 10 and the second housing 60. Exemplarily, the pressure ring 90 is in the shape of a semi-circular ring L, machined from an aluminum plate, with a thickness between 30 - 45 mm and having a circle of through holes. Specifically in the present application, the number of pressure rings is two, and the two pressure rings 90 are clamped on the first connection flange 80.

[0064] In one embodiment, as Figure 7 shown, the current transformer further includes an insulating partition 100; the insulating partition 100 is arranged between the pressure ring 90 and the transition flange 70.

[0065] Among them, the insulating partition 100 is an element for preventing magnetic field leakage. It is convenient for the coil 30 to induce the current flowing through the conductor 20.

[0066] Specifically, an insulating partition 100 is also provided between the pressure ring 90 and the transition flange 70, which cuts off the electrical conduction connection between the transition flange 70, the first housing 10 and the pressure ring 90, and can ensure the current flowing through the induction conductor 20 of the coil 30.

[0067] In one embodiment, the first housing 10, the second housing 60, and the transition flange 70 form a sealed cavity; the sealed cavity is filled with an insulating gas.

[0068] Specifically, the first housing 10, the second housing 60, and the transition flange 70 form a sealed cavity. In the cavity of this sealed cavity, a conductor 20 passes through. The conductor 20 is in the insulating gas and can withstand high voltage without breakdown or discharge.

[0069] In one embodiment, as Figure 8 shown, a conductive sealing ring 110 is provided between the protective cover 40 and the support platform 50.

[0070] Among them, the conductive sealing ring 110, as the name implies, is a kind of spare part that can not only play a sealing role but also has a conductive function. It is usually made of a conductive material (such as metal or conductive rubber), and through a specific structural design, the sealing ring can form a good conductive path on the contact surface.

[0071] Specifically, a conductive sealing ring 110 is provided between the protective cover 40 and the support platform 50. On the one hand, the conductive sealing ring 110 can effectively prevent external factors such as dust and moisture from invading the inside of the current transformer, thereby protecting the internal circuits and electronic components from damage. This is crucial for the stable operation of the current transformer. On the other hand, the effective electrical connection between the protective cover 40 and the first housing 10 is achieved through the conductive performance of the material of the conductive sealing ring 110.

[0072] In one embodiment, the annular coil 30 and the first housing 10 are integrally bonded by epoxy resin glue.

[0073] Specifically, the annular coil 30 and the first housing 10 are integrally bonded by epoxy resin glue, which can ensure the stability of the installation position of the annular coil 30.

[0074] In one embodiment, a gas-insulated metal-enclosed switchgear is also provided, including the current transformer according to any one of the above embodiments.

[0075] Among them, a gas-insulated metal-enclosed switchgear (GIS, Gas Insulated Switchgear) is a high-voltage electrical equipment, which is characterized in that at least a part uses a gas higher than atmospheric pressure as an insulating medium, and all devices or components are enclosed in a metal-grounded enclosure. Specifically, the gas-insulated metal-enclosed switchgear is composed of a circuit breaker, a disconnector, an earthing switch, a current transformer, a lightning arrester, a busbar, a connector, an outgoing terminal, etc. These devices or components are enclosed inside a metal-grounded enclosure and filled with SF6 insulating gas at a certain pressure. Therefore, GIS is also called SF6 completely enclosed combined electrical apparatus.

[0076] Specifically, in this embodiment, a gas-insulated metal-enclosed switchgear is further provided, including the current transformer in any one of the above embodiments, which can ensure the stable operation of the gas-insulated metal-enclosed switchgear.

[0077] In a specific embodiment, as Figure 9 shown, a current transformer in an actual scenario is further provided, including a conductor 20, a toroidal coil 30, a first housing 10, a second housing 60, a transition flange 70, an insulating partition 100, two compression rings 90, bolts 120, bolt insulating sheaths 130, a protective cover 40, and a conductive sealing ring 110.

[0078] The current transformer conductor 20 is made of an aluminum tube or an aluminum rod or a copper tube or a copper rod with good current-carrying performance by machining or casting.

[0079] As Figure 10 shown, the toroidal coil 30 is wound by an enameled copper wire around an iron core, and the iron core is made of very thin silicon steel sheets stacked or wound.

[0080] The first housing 10 is a thin-walled cylinder with an inner diameter of 450 mm to 500 mm and a wall thickness of 6 mm to 10 mm, welded by aluminum. It has a connecting flange at the lower part for the extended connection of the current transformer and external components. It has a circular support platform 50 in the middle for placing the toroidal coil; it has an L-shaped first connecting flange 80 at the upper part for connecting with the compression ring 90, the insulating partition 100, and the transition flange 70. As Figure 11 shown in the structural diagram of the transition flange, there are two sets of screw holes. The ones with a larger pitch circle diameter are used for connecting with the protective cover 40, and the ones with a smaller pitch circle diameter are used for connecting with the first housing 10 and the second housing 60.

[0081] The inner diameter of the toroidal coil 30 is larger than the outer diameter of the first connecting flange 80 on the first housing 10. The toroidal coil 30 is sleeved on the first housing 10 and placed on the support platform 50 of the first housing 10. The toroidal coil 30 and the first housing 10 are integrally bonded together with epoxy resin glue.

[0082] As shown Figure 12 in the figure, the second housing 60 is a thin-walled cylinder with an inner diameter of 500 mm to 550 mm and a wall thickness of 6 mm to 10 mm. It is made of aluminum by welding. It has two connecting flanges at the upper and lower parts: the upper connecting flange 140 and the lower connecting flange 150. The upper flange is used for the extended connection of the current transformer and external components, and the lower connecting flange 150 is used to connect with the transition flange 70.

[0083] The transition flange 70 is machined from an aluminum plate or cast from aluminum. Its thickness is 30 - 40 mm. It has two sets of staggered threads.

[0084] The insulating partition 100 is made by vacuum casting epoxy resin, with a thickness of 5 - 15 mm and a circle of through holes.

[0085] As shown Figure 13 , the pressure ring 90 is in the shape of a semi-circular ring L and is machined from an aluminum plate. Its thickness is between 30 - 45 mm. It has a circle of through holes. The pressure ring 90 is a semi-circular ring with an L-shaped cross-section, and two pressure rings 90 are clamped on the first connecting flange 80 with an L-shaped cross-section of the first housing.

[0086] The second housing 60 is bolted to the transition flange 70.

[0087] The first housing 10 and the insulating partition 100 are bolted to the transition flange 70 through two pressure rings 90 with an L-shaped cross-section and bolts 120. An insulating sheath 130 is sleeved on the bolts 120.

[0088] The insulating partition 100 and the insulating sheath 130 cut off the electrical conduction connection between the transition flange 70 and the first housing 10 and the pressure ring 90.

[0089] The first housing 10, the second housing 60, and the transition flange 70 are bolted together to form an integral body, which is filled with high-pressure insulating gas inside.

[0090] Sealing grooves are provided on the first housing 10, the second housing 60, and the transition flange 70.

[0091] Sealing rings are placed in the sealing grooves on the contact surfaces of the first housing 10, the second housing 60, and the transition flange 70 to seal the high-pressure insulating gas inside.

[0092] The protective cover 40 is made of aluminum (plate) by welding and is fixed to the transition flange 70 by bolt connection. The protective cover 40 and the first housing 10 form a closed structure that wraps the toroidal coil 30 to prevent the intrusion of moisture and other foreign objects.

[0093] A conductive sealing ring 110 is used between the protective cover 40 and the support platform 50 between the first housing, realizing the sealing and effective electrical connection between the protective cover 40 and the first housing.

[0094] The device provided in this embodiment overcomes the deficiencies of the prior art. The coil is placed outside the housing while ensuring the performance of the current transformer is achieved; it solves the problem that the possible moisture content inside the housing may deteriorate the insulation performance of the internal insulating medium, improving its insulation reliability. The reduction of the housing diameter significantly reduces the use of non-ferrous metal aluminum, and the material cost is significantly reduced. The coil is placed outside the housing, making installation, testing, and maintenance more convenient. The reasonable setting of the protective cover improves its environmental tolerance. The use of the conductive sealing ring between the protective cover and the first housing realizes the dual functions of sealing and electrical connection between the protective cover and the first housing.

[0095] Advantages of the current transformer for high-voltage GIS: 1. The coil is directly bonded to the housing, and no additional coil support needs to be set. 2. The housing only needs to accommodate the conductor and high-voltage gas, and does not need to accommodate the coil. The housing diameter is small, and the material cost is significantly reduced. 3. The coil is placed outside the housing, and its moisture content has little impact on the insulation inside the product, increasing the insulation reliability. 4. The coil is placed outside the housing, which is convenient for installation and testing, easy to maintain, and has low maintenance cost.

[0096] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, 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, it should be considered as the scope recorded in this application.

[0097] The above-described embodiments only represent several implementation manners of this application. Their descriptions are relatively specific and detailed, but they should not be construed as limiting the patent scope of this application. It should be noted that for those of ordinary skill in the art, without departing from the concept of this application, several deformations and improvements can still be made, and these all belong to the protection scope of this application. Therefore, the protection scope of this application should be subject to the appended claims.

Claims

1. A current transformer, characterized in that, The current transformer includes: A first housing configured to form a cavity, which is filled with an insulating gas; A conductor passing through the cavity and penetrating the first housing; A toroidal coil disposed around the first housing for inducing the current flowing through the conductor; A protective cover forming a closed structure with the first housing to enclose the toroidal coil.

2. The current transformer according to claim 1, wherein, The first housing is a cylinder. The wound toroidal coil enters from the first end of the first housing and is disposed around the first housing. A support platform for fixing the toroidal coil is provided at the second end of the first housing; The current transformer further includes a second housing, which is a cylinder; The second housing is connected to the first housing at the first end of the first housing. The conductor passes through the cavity formed by the second housing and penetrates the second housing.

3. The current transformer according to claim 2, characterized in that, The first housing is connected to the second housing through a transition flange.

4. The current transformer according to claim 3, characterized in that, A first connection flange is provided at the first end of the first housing. The first housing is connected to the transition flange based on the first connection flange.

5. The current transformer according to claim 4, characterized in that, The current transformer further includes a pressure ring with a through hole clamped on the first connection flange. The pressure ring is connected to the transition flange by bolts.

6. The current transformer according to claim 5, characterized in that, The current transformer further includes an insulating partition disposed between the pressure ring and the transition flange.

7. The current transformer according to claim 4, characterized in that, The first housing, the second housing, and the transition flange form a sealed cavity, which is filled with the insulating gas.

8. The current transformer according to claim 2, wherein, A conductive sealing ring is provided between the protective cover and the support platform.

9. The current transformer according to claim 1, characterized in that, The toroidal coil is integrally bonded to the first housing through epoxy resin glue.

10. A gas-insulated metal-enclosed switchgear, characterized in that, Including the current transformer according to any one of claims 1 to 9.

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