Isolation contact

Abstract

The utility model relates to the field of high-voltage electrical equipment, and provides an isolating contact, which comprises a moving contact, a shielding cover and an insulating cylinder, the shielding cover and the insulating cylinder are sleeved outside the moving contact, a screw rod mechanism is arranged in the moving contact, a conductor with high voltage is connected outside the moving contact, the shielding cover is arranged in the insulating cylinder, and the insulating cylinder is arranged in the insulating cylinder. The shielding case comprises a first shielding case, a second shielding case and a third shielding case which are arranged at intervals; the first shielding case is connected with the conductor in a high-voltage mode, the lead screw mechanism drives the moving contact to move towards or away from the second shielding case and the third shielding case, so that the moving contact is connected with the second shielding case and the third shielding case in a high-voltage mode, the field intensity in the air cavity is effectively reduced, partial discharge is reduced, and the compression strength is improved. The gap between the second shielding cover and the first shielding cover and the gap between the second shielding cover and the third shielding cover form a shielding fracture, the function of circuit breaking is achieved, and the electric field can be effectively shielded by setting the reasonable fracture length.

Description

Technical Field

[0001] The utility model relates to the field of high-voltage electrical equipment, in particular to an isolation contact. Background Art

[0002] High-voltage disconnectors are important switchgear in the electrical systems of power plants and substations. They need to be used in conjunction with high-voltage circuit breakers. Disconnectors are suitable for indoor installations with three-phase AC 50Hz and rated voltage 40.5KV. They are used to connect, disconnect or convert lines when high-voltage equipment is under voltage and load. The high-voltage disconnector drives the movement of the disconnecting contacts through a screw mechanism to achieve the closing, isolation and grounding of the three positions of the disconnector. When the disconnecting contacts are in the closed and conducting state, in order to prevent electric shock, an insulating cylinder is usually installed on the disconnecting contacts. However, considering the compactness of the overall size of the high-voltage disconnector, it is not convenient to make the insulating cylinder larger.

[0003] However, when the thickness of the insulation tube is small, there is a possibility of breakdown. The ground fault current caused by the leakage current may cause electric shock and personal injury. At the same time, it may also cause insulation breakdown under normal operating voltage and cause a short circuit, and the high-voltage disconnector will fail to close. Utility Model Content

[0004] The utility model aims to provide an isolating contact, aiming to improve the problem that the existing insulating tube is limited in size and may be broken down.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] An isolating contact, comprising a moving contact, a shielding cover and an insulating cylinder sleeved outside the moving contact, wherein a screw mechanism is arranged inside the moving contact, a conductor with high voltage is connected to the outside of the moving contact, the shielding cover is arranged inside the insulating cylinder, and the shielding cover comprises a first shielding cover, a second shielding cover and a third shielding cover arranged in a gap;

[0007] The first shielding cover is connected to the conductor at high voltage, the screw mechanism drives the moving contact to move toward or away from the second shielding cover and the third shielding cover, and the moving contact is connected or disconnected from the second shielding cover and the third shielding cover at high voltage, and the gap between the second shielding cover and the first shielding cover and the third shielding cover forms a shielding fracture.

[0008] Preferably, the axial length of the shielding fracture is 40-55 mm.

[0009] Preferably, the shielding cover is made of brass.

[0010] Preferably, the insulating tube is made of epoxy resin material.

[0011] Preferably, the insulating cylinder includes an isolation cylinder and an insulating shell which are arranged on the moving contact from the inside to the outside, the first shielding cover is arranged at one end of the insulating shell close to the conductor, the third shielding cover is arranged at one end of the insulating shell away from the conductor, and the second shielding cover is arranged in the middle of the isolation cylinder.

[0012] Preferably, an annular contact seat is provided in the middle of the moving contact, the inner wall of the contact seat is connected to the moving contact, and the second shielding cover is locked on the contact seat.

[0013] Preferably, the surface of the insulating shell is coated with a semiconductor coating.

[0014] After adopting the above technical solution, the utility model has the following advantages compared with the background technology:

[0015] 1. In the utility model, the characteristics of the moving contact moving and connecting with the outgoing conductor are cleverly utilized to realize the closing and opening of the switch. On the path of the axial movement of the moving contact, shielding covers that can be connected to high voltage are arranged at intervals on the insulating cylinder. When the shielding cover is connected to high voltage, the induced voltage of the insulating cylinder near the end of the cover body increases, and the high-voltage pressure difference between the insulating cylinder and the moving contact decreases, which effectively reduces the field strength in the air cavity, reduces partial discharge, and improves the withstand voltage strength.

[0016] 2. In the utility model, the axial length of the shielding break is 40-55mm, so that the minimum induced voltage of the insulating tube near the shielding break and the high voltage difference of the moving contact are within a small reasonable range, effectively uniformizing the electric field in the insulating tube, and may cause local discharge. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the isolating switch described in the utility model;

[0018] Figure 2 It is a structural schematic diagram of the isolating switch described in the utility model;

[0019] Figure 3 for Figure 1 An enlarged schematic diagram of the structure of part A is shown.

[0020] Description of reference numerals:

[0021] 1. Moving contact; 2. Shielding cover; 21. First shielding cover; 22. Second shielding cover; 23. Third shielding cover; 24. Shielding fracture; 3. Insulating cylinder; 31. Isolating cylinder; 32. Insulating shell; 4. Screw mechanism; 5. Conductor; 6. Air cavity; 7. Contact seat; 8. Outgoing conductor. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0023] In addition, it should be noted that the terms "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element of the present invention must have a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0024] When an element is referred to as being “fixed to” or “disposed on” or “provided on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0025] Unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the utility model can be understood according to specific circumstances.

[0026] Example

[0027] Please refer to Figure 1 and Figure 2 As shown, this embodiment provides an isolating contact, including a moving contact 1 and a shielding cover 2 and an insulating cylinder 3 which are sleeved outside the moving contact 1, a screw mechanism 4 is provided inside the moving contact 1, a conductor 5 with high voltage is connected to the outside of the moving contact 1, an air cavity 6 is provided between the insulating cylinder 3 and the moving contact 1, the shielding cover 2 is arranged in the insulating cylinder 3, and the shielding cover 2 includes a first shielding cover 21, a second shielding cover 22 and a third shielding cover 23 which are arranged in a gap; the first shielding cover 21 is connected to the conductor 5 at high voltage, the screw mechanism 4 drives the moving contact 1 to move toward or away from the second shielding cover 22 and the third shielding cover 23, and the moving contact 1 is connected or disconnected with the second shielding cover 22 and the third shielding cover 23 at high voltage, and the gap between the second shielding cover 22 and the first shielding cover 21 and the third shielding cover 23 forms a shielding fracture 24.

[0028] Specifically, the screw mechanism 4 drives the moving contact 1 to move, so that the moving contact 1 is connected or disconnected with the outgoing conductor 8, thereby realizing the closing and opening of the isolating contact. On this basis, on the axial movement path of the moving contact 1, a shielding cover 2 that can be connected to high voltage is arranged on the insulating cylinder 3 at intervals. When the shielding cover 2 is connected to high voltage, the induced voltage of the insulating cylinder 3 near the end of the cover body increases, and the high-voltage pressure difference between the insulating cylinder 3 and the moving contact 1 decreases, thereby effectively reducing the field strength in the air cavity 6, reducing partial discharge, and improving the withstand voltage strength, making the product safer and more reliable, and extending the service life of the product.

[0029] Among them, the first shielding cover 21 is connected to the conductor 5 to introduce high voltage, the second shielding cover 22 is connected to the moving contact 1 through the contact seat 7 to introduce high voltage, and the third shielding cover 23 is connected to the outgoing conductor 8, so that when the moving contact 1 is connected to the outgoing conductor 8, the third shielding cover 23 introduces high voltage. The first shielding cover 21, the second shielding cover 22 and the third shielding cover 23 are arranged in a gap, and the first part is not connected, which has the effect of a break. In the process of the moving contact 1 approaching the outgoing conductor 8, when the moving contact 1 is not connected to the contact seat 7, only the first shielding cover There is high voltage on 21. When the moving contact 1 is connected to the contact seat 7 but not in contact with the outgoing conductor 8, there is high voltage on the first shielding cover 21 and the second shielding cover 22. At this time, the isolating contact is still in the open state. When the moving contact 1 is in contact with the outgoing conductor 8, there is high voltage distribution on the first shielding cover 21, the second shielding cover 22 and the third shielding cover 23. At this time, the isolating contact is in the closed state. This design cleverly utilizes the characteristics of the moving contact 1 moving and connecting with the outgoing conductor 8 to achieve closing and opening. The structure is simple and practical.

[0030] In addition, the contact seat 7 is annularly arranged in the middle of the moving contact 1 , the inner wall of the contact seat 7 is connected to the moving contact 1 , and the second shielding cover 22 is locked on the contact seat 7 .

[0031] Furthermore, if Figure 1 and Figure 3 As shown, the axial length d of the shielding break 24 is 40-55mm. In the utility model, adjusting the axial length d of the shielding break 24 can control the minimum induced voltage of the insulating tube 3 near the shielding break 24. When the axial length d of the break decreases, the minimum induced voltage increases, the induced voltage of the insulating tube 3 and the high voltage pressure difference of the moving contact 1 decreases, and the field strength decreases. Therefore, the axial length d of the shielding break 24 should not be too large. If the axial length d is too large, local discharge may occur. In a preferred embodiment, the axial length d of the shielding break 24 is 52.5mm.

[0032] Furthermore, the material of the shielding cover 2 is brass, which is a copper alloy containing a certain amount of zinc and has good conductivity. In addition, other metals such as tin, iron, aluminum, lead, silicon and manganese can be added to brass. The addition of other metals can achieve unique properties. For example, the zinc content in brass helps to improve the ductility and strength of brass-based copper materials. The higher the zinc content in brass, the stronger the elasticity of the alloy and the easier it is to process.

[0033] Furthermore, the insulating tube 3 is made of epoxy resin material. The epoxy resin material has large cohesion, strong adhesion, good flexibility, excellent thermal curing performance and stable chemical corrosion resistance and other outstanding advantages in organic insulating materials. It can be made into various solid materials by vacuum casting through an epoxy resin casting system such as an automatic epoxy pressure gel manufacturing process (APG process). The insulating tube 3 made of epoxy resin material in the utility model has strong arc resistance, high density, smooth surface, good cold resistance and heat resistance, good electrical insulation performance and other advantages.

[0034] Furthermore, the insulating cylinder 3 includes an isolation cylinder 31 and an insulating shell 32 which are arranged on the moving contact 1 from the inside to the outside, the first shielding cover 21 is arranged at the end of the insulating shell 32 close to the conductor 5, the third shielding cover 23 is arranged at the end of the insulating shell 32 away from the conductor 5, and the second shielding cover 22 is arranged in the middle of the isolation cylinder 31, wherein the first shielding cover 21 and the third shielding cover 23 are cast inside the insulating shell 32 in advance, and the second shielding cover 22 is cast inside the isolation cylinder 31 in advance, and finally the insulating shell 32 and the isolation cylinder 31 are combined into one to form the insulating cylinder 3.

[0035] Furthermore, the surface of the insulating shell 32 is coated with a semiconductor coating to achieve grounding of the entire outer insulating surface and reduce the corrosion effects of the operating environment, thereby maintaining the integrity of the insulating cylinder 3 and reducing potential adverse effects of external substances.

[0036] It should be noted that the isolating contact of the utility model is applied to the isolating switch. When the moving contact 1 moves to abut against the outgoing conductor 8, this position is the closed-circuit state of the grounding opening and isolating closing. The insulating cylinder 3 of the utility model is only a shell structure outside the closing chamber and does not include other modules.

[0037] The above is only a preferred specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the utility model should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. An isolating contact, characterized in that: It comprises a moving contact, a shielding cover and an insulating cylinder sleeved outside the moving contact, a screw mechanism is arranged inside the moving contact, a conductor with high voltage is connected outside the moving contact, the shielding cover is arranged inside the insulating cylinder, and the shielding cover comprises a first shielding cover, a second shielding cover and a third shielding cover arranged in a gap; The first shielding cover is connected to the conductor at high voltage, the screw mechanism drives the moving contact to move toward or away from the second shielding cover and the third shielding cover, and the moving contact is connected or disconnected from the second shielding cover and the third shielding cover at high voltage, and the gap between the second shielding cover and the first shielding cover and the third shielding cover forms a shielding fracture.

2. The isolating contact according to claim 1, characterized in that: The axial length of the shielding fracture is 40-55 mm.

3. The isolating contact according to claim 1, characterized in that: The material of the shielding cover is brass.

4. The isolating contact according to claim 1, characterized in that: The insulating cylinder is made of epoxy resin material.

5. The isolating contact according to claim 4, characterized in that: The insulating cylinder includes an isolation cylinder and an insulating shell which are arranged on the moving contact from the inside to the outside, the first shielding cover is arranged at one end of the insulating shell close to the conductor, the third shielding cover is arranged at one end of the insulating shell away from the conductor, and the second shielding cover is arranged in the middle of the isolation cylinder.

6. The isolating contact according to claim 1, characterized in that: An annular contact seat is provided in the middle of the moving contact, the inner wall of the contact seat is connected to the moving contact, and the second shielding cover is locked on the contact seat.

7. The isolating contact according to claim 5, characterized in that: The surface of the insulating shell is coated with a semiconductor coating.

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