A three-position disconnector

Abstract

The utility model discloses a three position isolator belongs to switch equipment technical field, including the on contact in left side, the intermediate static contact in on contact right side, the movable moving dynamic contact that has in the intermediate static contact coaxial installation and the grounding contact that is located the intermediate static contact right side and is fixedly connected on the cabinet body aluminum plate, through the left movement of adjusting dynamic contact can control its with on contact contact or disconnect, through the right movement of adjusting dynamic contact can control its with grounding contact contact or disconnect. Through the improvement three position isolator space layout and switching structure, under the electric field distribution uneven of low pressure N2 / dry air insulating medium, the problem of insufficient creepage distance is solved, and the environmental protection requirement is met simultaneously.

Description

Technical Field

[0001] This utility model relates to the field of switchgear technology, specifically a three-position disconnect switch. Background Technology

[0002] Currently, most 40.5kV gas-insulated switchgear on the market uses low-pressure SF6 gas as the insulating medium, paired with a knife-switch type three-position disconnector. Although SF6 gas has excellent insulation and arc-extinguishing properties, its greenhouse effect is significant (global warming potential GWP is approximately 23,500), which does not meet environmental protection requirements. Therefore, the industry is gradually exploring technical solutions to replace SF6 with low-pressure N2 / dry air.

[0003] However, the insulation strength of N2 / dry air is lower than that of SF6, requiring a larger creepage distance and a more optimized electric field distribution at the same voltage level. The structural design of traditional knife-switch type three-position disconnect switches (such as contact layout and insulation configuration) is not optimized for the characteristics of low-pressure media, which makes gas-filled switchgear using N2 / dry air as the insulating medium prone to phase-to-phase and phase-to-ground discharges or even breakdowns, failing to meet practical application requirements. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a three-position disconnect switch. By improving the spatial layout and switching structure of the three-position disconnect switch, the problem of uneven electric field distribution and insufficient creepage distance under low-pressure N2 / dry air insulating medium is solved, while meeting environmental protection requirements.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A three-position disconnect switch includes a left-side contact, a middle stationary contact to the right of the contact, a movable contact coaxially mounted on the middle stationary contact that can move left and right, and a grounding contact to the right of the middle stationary contact and fixedly connected to an aluminum plate of the cabinet. By adjusting the leftward movement of the movable contact, it can be controlled to make contact with or break off from the contact; by adjusting the rightward movement of the movable contact, it can be controlled to make contact with or break off from the grounding contact.

[0007] By adopting the above scheme, the three-position disconnecting switch in this three-position disconnecting switch has the connecting contact, intermediate stationary contact and grounding contact evenly distributed on the left and right, which optimizes the electric field distribution in the compartment; secondly, the design of switching by moving the moving contact left and right solves the problem of phase-to-phase / phase-to-ground discharge under low pressure N2 / dry air by reducing the range of movement of the moving contact during switching, and makes the creepage distance more in line with the requirements.

[0008] As a preferred embodiment of a three-position disconnecting switch, the three-position disconnecting switch further includes a supporting insulator fixedly connected to the bottom side of the closing contact and an intermediate insulator fixedly connected to the bottom side of the intermediate stationary contact; wherein, the supporting insulator is used for further fixing of the closing contact, and the intermediate insulator is used to connect two adjacent compartments, such as connecting the upper air-filled compartment and the lower air-filled compartment.

[0009] As a preferred embodiment of a three-position disconnect switch, the three-position disconnect switch also includes an internal threaded hole coaxially opened at the center of the moving contact, a magnetic fluid fixedly connected to the aluminum plate, and a transmission screw coaxially installed in the intermediate stationary contact; the left end of the transmission screw is installed by threading into the internal threaded hole, and the transmission screw is driven to rotate by the magnetic fluid to realize the linear movement of the moving contact.

[0010] As a preferred embodiment of a three-position disconnect switch, at least one guide groove is provided on the outer side wall of the moving contact, and the guide groove is a through groove with openings on both the left and right sides; multiple axially arrayed guide mounting holes are provided through the side wall of the middle stationary contact, and guide plates extending into the guide groove are detachably installed in the guide mounting holes. The guide groove restricts the moving contact to move only axially, thus preventing the moving contact from deflecting.

[0011] As a preferred embodiment of a three-position disconnector, annular mounting grooves are provided on the inner sides of the grounding contact, intermediate stationary contact, and closing contact. Annular spring contact fingers are fitted within the annular mounting grooves for limiting the movement of the contact. The moving contact is firmly in contact with the closing contact, intermediate stationary contact, or grounding contact through the annular spring contact fingers. The compression of the spring contact fingers is less than 0.5mm after being compressed. The moving contact is in close contact with the corresponding contact through the spring contact fingers, ensuring low contact resistance under low-pressure media.

[0012] As a preferred embodiment of a three-position disconnect switch, the three-position disconnect switch further includes a contact shield installed at the right end of the grounding contact, the left and right ends of the intermediate stationary contact, and the left end of the contact contact; the ends of the grounding contact, the intermediate stationary contact, and the contact contact are each provided with at least one shield mounting hole, and the contact shield is fixed in each shield mounting hole by installing hexagon countersunk screws. All hexagon countersunk screws are completely recessed into the contact shield, thereby suppressing tip discharge and further optimizing the electric field distribution.

[0013] As a preferred embodiment of a three-position disconnect switch, the closing contact is equipped with a guide sleeve facing the moving contact. The right end of the guide sleeve is tapered, so that the moving contact can be concentrically inserted into the guide sleeve when it moves to the left, further improving the coaxiality and reducing the difficulty of contact between the two.

[0014] The beneficial effects of this utility model are:

[0015] 1. Adaptable to low-pressure media: The three-position disconnect switch in this three-position disconnect switch has the connecting contact, intermediate stationary contact and grounding contact evenly distributed on the left and right, which optimizes the electric field distribution in the compartment; secondly, the design of switching by moving the moving contact left and right solves the problem of phase-to-phase / phase-to-ground discharge under low-pressure N2 / dry air due to the small range of movement of the moving contact during switching, making the creepage distance more compliant with requirements.

[0016] 2. Environmental friendliness: Replacing SF6 with low-pressure N2 / dry air results in near-zero greenhouse gas emissions, meeting the requirements of the "dual carbon" policy.

[0017] 3. High operational reliability: The moving contact of the three-position disconnect switch is constrained by a "screw-nut transmission (magnetic fluid drive) + guide structure", which ensures high movement accuracy and avoids deflection; the spring contact finger compression is small (≤0.5mm), which ensures good conductivity under low pressure and reduces contact wear, extending service life; the operating mechanism supports electric (automatic) and manual (emergency) dual modes to adapt to different scenario requirements; the indicating mechanism provides real-time status feedback for easy monitoring. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 Main view structural diagram of a three-position disconnector used in an environmentally friendly gas-insulated switchgear;

[0020] Figure 2 for Figure 1 Main view of the three-position disconnector;

[0021] Figure 3 for Figure 2 Cross-sectional view of the moving contact;

[0022] Figure 4 for Figure 2 Longitudinal sectional view of the moving contact;

[0023] Figure 5 for Figure 2 Cross-sectional view of the middle stationary contact;

[0024] Figure 6 for Figure 2 Main view of the intermediate contact;

[0025] Figure 7 for Figure 2Front view of the guide vane;

[0026] Figure 8 for Figure 2 Front view of the spring-loaded contact finger;

[0027] The markings in the diagram are: 1-Three-position disconnect switch; 101-Magnetic fluid; 102-Aluminum plate; 103-Grounding contact; 104-Intermediate stationary contact; 105-Moving contact; 106-Connecting contact; 107-Supporting insulator; 108-Shielding cover; 109-Intermediate insulator; 110-Drive screw; 111-Internal threaded hole; 112-Guide groove; 113-Guide mounting hole; 114-Shielding cover mounting hole; 115-Guide sleeve; 116-Contact guide plate; 117-Annular mounting groove; 118-Annular spring contact finger; 2-Three-position operating mechanism. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0029] like Figures 1 to 2As shown, a three-position disconnect switch is provided, which is used in an environmentally friendly gas-insulated switchgear. Specifically, it includes a left-side contact 106, a middle stationary contact 104 to the right of the contact 106, a movable contact 105 coaxially mounted on the middle stationary contact 104 and capable of moving left and right, and a grounding contact 103 located to the right of the middle stationary contact 104 and fixedly connected to the aluminum plate 102 of the switchgear. By adjusting the leftward movement of the movable contact 105, its contact with or disconnection from the contact 106 can be controlled. The rightward movement of head 105 can control its contact or disconnection with grounding contact 103; the three-position disconnecting switch 1 also includes a support insulator 107 fixedly connected to the bottom side of the contact 106 and located at the bottom of the upper gas-filled compartment, and an intermediate insulator 109 fixedly connected to the bottom side of the intermediate stationary contact 104 and located at the bottom of the upper gas-filled compartment; wherein, the support insulator 107 is used for further fixing the contact 106, and the intermediate insulator 109 is used to connect two adjacent compartments, such as connecting the upper gas-filled compartment and the lower gas-filled compartment. The three-position disconnector 1 has the connecting contact 106, the intermediate stationary contact 104, and the grounding contact 103 evenly distributed on the left and right sides, which optimizes the electric field distribution in the compartment. After testing, the partial discharge amount is ≤5pC (the standard requirement is ≤10pC), and the electric field distribution is more uniform. Secondly, the design of switching by moving the moving contact 105 left and right solves the problem of phase-to-phase / phase-to-ground discharge under low-pressure N2 / dry air by solving the problem of phase-to-phase / phase-to-ground discharge under low-pressure N2 / dry air, making the creepage distance more compliant with the requirements. After testing, the power frequency withstand voltage (phase-to-ground / phase-to-phase) is 42kV / 48kV (the standard requirement is 42kV / 42kV), with no breakdown or flashover.

[0030] like Figure 2 As shown, the three-position disconnect switch 1 also includes an internal threaded hole 111 coaxially opened at the center of the moving contact 105, a magnetic fluid 101 fixedly connected to the aluminum plate 102, and a transmission screw 110 coaxially installed in the intermediate stationary contact 104; the left end of the transmission screw 110 is installed in conjunction with the internal threaded hole 111 through a thread, and the transmission screw 110 is driven to rotate by the magnetic fluid 101 to realize the linear movement of the moving contact 105.

[0031] like Figures 4 to 5 , Figure 7 As shown, at least one guide groove 112 (two symmetrical grooves in the figure) is provided on the outer side wall of the moving contact 105. The guide groove 112 is a through groove with openings on both the left and right sides. Multiple axially arrayed guide mounting holes 113 are provided through the side wall of the middle stationary contact 104. A guide piece extending into the guide groove 112 is detachably installed in the guide mounting hole 113. The guide groove 112 restricts the moving contact 105 to move only axially, thus preventing the moving contact 105 from deflecting.

[0032] like Figure 5 , Figure 8As shown, annular mounting grooves 117 are provided on the inner sides of the grounding contact 103, the intermediate stationary contact 104, and the connecting contact 106. Annular spring fingers 118 are fitted into the annular mounting grooves 117 for limiting. The moving contact 105 is firmly in contact with the connecting contact 106, the intermediate stationary contact 104, or the grounding contact 103 through the annular spring fingers 118. The compression of the spring fingers is less than 0.5 mm after being compressed. The moving contact 105 is in close contact with the corresponding contact through the spring fingers to ensure low contact resistance under low pressure medium.

[0033] like Figure 2 As shown, the three-position disconnect switch 1 also includes a contact shield 108 installed at the right end of the grounding contact 103, the left and right ends of the intermediate stationary contact 104, and the left end of the contact 106. At least one mounting hole for the shield 108 is opened at the end of the grounding contact 103, the intermediate stationary contact 104, and the contact 106 (two symmetrical holes are shown in the figure). The contact shield 108 is fixed in each mounting hole by installing hexagonal countersunk screws. All hexagonal countersunk screws are completely recessed into the contact shield 108 (the hexagonal countersunk screws are omitted in the figure), thereby suppressing tip discharge and further optimizing the electric field distribution.

[0034] like Figure 6 As shown, the connecting contact 106 is equipped with a guide sleeve 115 facing the moving contact 105. The right end of the guide sleeve 115 is tapered. When the moving contact 105 moves to the left, it can be concentrically inserted into the guide sleeve 115, further improving the coaxiality and reducing the difficulty of contact between the two.

[0035] The usage method of the three-position disconnect switch is as follows:

[0036] a: When the three-position switch is in the grounded position, the moving contact 105 simultaneously contacts the intermediate stationary contact 104 and the grounding contact 103. At this time, the magnetic fluid 101 and the trigger screw are driven to rotate synchronously by manual or electric operation (implemented by the three-position operating mechanism 2). Then, the moving contact 105 moves from the grounding contact 103 to the intermediate stationary contact 104 under the transmission of the thread until the moving contact 105 only contacts the intermediate stationary contact 104, which can realize the switch from grounding to isolation.

[0037] b: When the three-position switch is in the isolated position, the moving contact 105 only contacts the intermediate stationary contact 104. At this time, the magnetic fluid 101 and the trigger screw are driven to rotate synchronously by manual or electric operation (implemented by the three-position operating mechanism 2). Then, the moving contact 105 moves from the intermediate stationary contact 104 to the closed contact 106 under the transmission of the thread until the moving contact 105 contacts both the intermediate stationary contact 104 and the closed contact 106 at the same time, so that the switch can be switched from isolated to closed.

[0038] c: When the three-position switch is in the ON position, the moving contact 105 simultaneously contacts the intermediate stationary contact 104 and the ON contact 106. At this time, the magnetic fluid 101 and the trigger screw are driven to rotate synchronously by manual or electric operation (implemented by the three-position operating mechanism 2). Then, the moving contact 105 moves from the ON contact 106 to the intermediate stationary contact 104 under the transmission of the thread until the moving contact 105 only contacts the intermediate stationary contact 104, which can realize the switch from ON to ON.

[0039] d: When the three-position switch is in the isolated position, the moving contact 105 only contacts the intermediate stationary contact 104. At this time, the magnetic fluid 101 and the trigger screw are driven to rotate synchronously by manual or electric operation (implemented by the three-position operating mechanism 2). Then, the moving contact 105 moves from the intermediate stationary contact 104 to the grounding contact 103 under the transmission of the thread until the moving contact 105 contacts both the intermediate stationary contact 104 and the grounding contact 103 at the same time, so that the switch can be switched from isolated to grounded.

[0040] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A three-position disconnect switch, characterized in that: It includes a contact on the left, a stationary contact on the right, a movable contact that can move left and right and is coaxially mounted on the stationary contact, and a grounding contact on the right side of the stationary contact and fixedly connected to the aluminum plate of the cabinet. By adjusting the leftward movement of the moving contact, it can be controlled to make contact with or break off from the closing contact; by adjusting the rightward movement of the moving contact, it can be controlled to make contact with or break off from the grounding contact.

2. The three-position disconnect switch according to claim 1, characterized in that: The three-position disconnector also includes a supporting insulator fixedly connected to the bottom side of the contact and an intermediate insulator fixedly connected to the bottom side of the intermediate stationary contact.

3. The three-position disconnect switch according to claim 1, characterized in that: The three-position disconnect switch also includes an internal threaded hole coaxially opened at the center of the moving contact, a magnetorheological fluid fixedly connected to the aluminum plate, and a transmission screw coaxially installed in the intermediate stationary contact; the left end of the transmission screw is installed by threading into the internal threaded hole.

4. The three-position disconnect switch according to claim 1, characterized in that: At least one guide groove is provided on the outer side wall of the moving contact, and the guide groove is a through groove with openings on both the left and right sides; multiple guide mounting holes are provided through the side wall of the middle stationary contact in an axial array, and guide plates extending into the guide groove are detachably installed in the guide mounting holes.

5. The three-position disconnect switch according to claim 1, characterized in that: The grounding contact, intermediate stationary contact, and connecting contact are all provided with annular mounting grooves on their inner sides. Annular spring contact fingers are fitted into the annular mounting grooves for limiting their position. The moving contact is firmly in contact with the connecting contact, intermediate stationary contact, or grounding contact through the annular spring contact fingers.

6. The three-position disconnect switch according to claim 1, characterized in that: The three-position disconnect switch also includes a contact shield installed at the right end of the grounding contact, the left and right ends of the intermediate stationary contact, and the left end of the contact contact; at least one shield mounting hole is opened at the end of the grounding contact, the intermediate stationary contact, and the contact contact, and the contact shield is fixed in each shield mounting hole by installing hexagon countersunk screws.

7. The three-position disconnect switch according to claim 6, characterized in that: All hex socket countersunk screws are fully recessed into the contact shield.

8. The three-position disconnect switch according to claim 1, characterized in that: The contact is equipped with a guide sleeve facing the moving contact. The right end of the guide sleeve is tapered, and the moving contact can be concentrically inserted into the guide sleeve when it moves to the left.

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