Ring main unit and its three-position switch

Abstract

The present disclosure provides a ring network cabinet and a three-position switch thereof, wherein the ring network cabinet comprises a three-position switch, and the three-position switch comprises a mechanism input shaft and at least one switch unit. The switch unit comprises a crank plate, a grounding contact, an insulating connecting plate and a moving contact. The crank plate is fixedly connected to the mechanism input shaft and can rotate with the mechanism input shaft, and has a first end and a second end. The grounding contact is connected to the first end of the crank plate, and one end of the insulating connecting plate is connected to the second end of the crank plate. The moving contact is movably connected to the other end of the insulating connecting plate, the first end of the moving contact is movably connected to the moving contact seat, the second end of the moving contact is a free end, and the connection point between the moving contact and the insulating connecting plate is located between the first end of the moving contact and the second end of the moving contact. When the mechanism input shaft rotates in the grounding closing direction, the moving contact and the grounding contact move relative to each other and both move in the closing direction.

Description

Technical Field

[0001] The present disclosure relates to the technical field of electrical equipment, and in particular to a ring main unit and a three-position switch thereof. Background Art

[0002] As an important component in the primary electrical circuit of the ring network cabinet, the three-position switch not only needs to carry the rated continuous current, rated short-time withstand current and rated closing current, but also needs to meet the requirements of reliable connection, high stability and low contact resistance. The three-position switch integrates the functions of both the isolating switch and the grounding switch, and it uses a moving contact to achieve mechanical locking. The three positions refer to three working positions: 1. The closing position where the main break of the isolating switch is connected; 2. The isolating position where the main break is separated; 3. The grounding position on the grounding side. When the three-position switch is tested for the rated short-circuit closing current of the grounding switch, it is often necessary to increase the closing speed of the grounding part. However, the traditional three-position switch often increases the closing speed of the grounding part by increasing the operating power of the operating mechanism of the three-position switch, but this often reduces the service life of the operating mechanism and the three-position switch, which is not conducive to the stability of the product. Summary of the invention

[0003] In order to solve the problem of reduced service life and stability in the related art of increasing the closing speed of the grounding part by increasing the operating work of the operating mechanism, the present disclosure provides another ring main unit and a three-position switch thereof that can increase the closing speed of the grounding part.

[0004] The present disclosure provides a three-position switch, characterized in that it is applied to a ring main unit, comprising:

[0005] A mechanism input shaft, which can be connected to the three-position operating mechanism and rotate under the drive of the three-position operating mechanism; and

[0006] At least one switch unit, each switch unit comprising:

[0007] A crank arm plate, fixedly connected to the mechanism input shaft and capable of rotating with the mechanism input shaft, the crank arm plate having a first end and a second end;

[0008] A grounding contact connected to the first end of the crank arm plate;

[0009] An insulating connecting plate, one end of which is connected to the second end of the crank arm plate;

[0010] A moving contact, which is movably connected to the other end of the insulating connecting plate, the first end of the moving contact is movably connected to the moving contact seat, the moving contact seat can be fixed on a fixed frame, the fixed frame is fixed on the inner wall of the gas box of the ring network cabinet, the second end of the moving contact is a free end, and the connection point between the moving contact and the insulating connecting plate is located between the first end of the moving contact and the second end of the moving contact;

[0011] When the input shaft of the mechanism rotates in the earthing and closing direction, the moving contact and the earthing contact move relative to each other and both move in the closing direction.

[0012] Optionally, the area of ​​the first end of the crank arm plate is larger than the area of ​​the second end.

[0013] Optionally, the area of ​​the crank arm plate gradually decreases from the first end to the second end.

[0014] Optionally, the distance from the connection point between the crank arm plate and the grounding contact to the mechanism input shaft is smaller than the distance from the connection point between the crank arm plate and the insulating connecting plate to the mechanism input shaft;

[0015] The pin shaft at the connection between the crank arm plate and the insulating connecting plate is in the same straight line as the mechanism input shaft, and the connection point between the first end of the crank arm plate and the grounding contact deviates from the straight line.

[0016] Optionally, the switch unit further comprises an isolating static contact, the isolating static contact is fixed on an isolating contact seat, the isolating contact seat can be fixed on the fixed frame, and the second end of the moving contact can be electrically connected to the grounding contact or to the isolating static contact under the drive of the mechanism input shaft;

[0017] When the three-position switch is grounded and opened, when the input shaft of the mechanism rotates in a first direction, the first end of the crank arm plate drives the grounding contact to rotate in the first direction, and the second end of the crank arm plate drives the moving contact to rotate in a second direction opposite to the first direction through the insulating connecting plate, so that the grounding contact and the moving contact move in the opening direction at the same time;

[0018] When the three-position switch is grounded and closed, the mechanism input shaft rotates in the second direction, the first end of the crank arm plate drives the grounding contact to rotate in the second direction, and the second end of the crank arm plate drives the moving contact to rotate in the first direction through the insulating connecting plate, so that the moving contact and the grounding contact move in the closing direction at the same time.

[0019] Optionally, the isolating static contact is located on a path where the moving contact rotates in a first direction, and the grounding contact is located on a path where the moving contact rotates in a second direction.

[0020] Optionally, the moving contact and the insulating connecting plate are both in the shape of long strips, and the connection point between the moving contact and the insulating connecting plate is located in the middle of the moving contact.

[0021] Optionally, the three-position switch further includes a grounding busbar, and the grounding busbar is connected to the housing of the ring network cabinet through a flexible connection;

[0022] The grounding contact is connected to the grounding busbar.

[0023] Optionally, the three-position switch is applied to a three-phase current switch device, and one switch unit is provided for each phase of current, and the crank plates of each switch unit are arranged at intervals on the input shaft of the mechanism;

[0024] The grounding contacts of each switch unit are connected to the grounding busbar.

[0025] The present disclosure provides a ring main unit, which comprises a gas box, the above-mentioned three-position switch arranged inside the gas box, and a three-position operating mechanism arranged in a mechanism room;

[0026] A fixed frame is installed on the inner wall of the gas box, and the moving contact seat of the three-position switch is fixed on the fixed frame. The gas box is filled with insulating gas.

[0027] The three-position operating mechanism is connected to the mechanism input shaft of the three-position switch and can drive the mechanism input shaft to rotate.

[0028] The technical solution provided by the embodiments of the present disclosure may have the following beneficial effects:

[0029] The present disclosure provides a three-position switch, which includes a mechanism input shaft and at least one switch unit. The mechanism input shaft can be connected to the three-position operating mechanism and rotate under the drive of the three-position operating mechanism. The switch unit includes a crank plate, a grounding contact, an insulating connecting plate and a moving contact. The crank plate is fixedly connected to the mechanism input shaft and can rotate with the rotation of the mechanism input shaft. The crank plate has a first end and a second end. The grounding contact is connected to the first end of the crank plate, and one end of the insulating connecting plate is connected to the second end of the crank plate. The moving contact is movably connected to the other end of the insulating connecting plate. The first end of the moving contact is movably connected to the moving contact seat. The moving contact seat can be fixed on a fixed frame. The fixed frame is fixed on the inner wall of the air box of the ring network cabinet. The second end of the moving contact is a free end. The connection point between the moving contact and the insulating connecting plate is located between the first end of the moving contact and the second end of the moving contact. When the mechanism input shaft rotates in the grounding closing direction, the moving contact and the grounding contact move relative to each other and both move in the closing direction. Since the grounding contact and the moving contact move relative to each other and move toward the grounding closing direction at the same time, the closing speed of the grounding contact and the moving contact is increased, which can effectively reduce the arc burning time, reduce contact erosion, and increase the service life of the product. Compared with the traditional technology of increasing the closing speed by increasing the spring energy and other means of increasing the mechanism operating work, the service life of the operating mechanism and the three-position switch is increased, and the stability of the product is improved.

[0030] The present disclosure also provides a ring network cabinet, which includes a gas box, the above-mentioned three-position switch arranged inside the gas box, and a three-position operating mechanism arranged in the mechanism room. A fixed frame is installed on the inner wall of the gas box, and the moving contact seat of the three-position switch is fixed on the fixed frame. The inside of the gas box is filled with insulating gas. The three-position operating mechanism is connected to the mechanism input shaft of the three-position switch and can drive the mechanism input shaft to rotate. Since the ring network cabinet of the present disclosure adopts the above-mentioned three-position switch, it can effectively reduce the arc burning time of the three-position switch, reduce contact ablation, and increase the service life of the product.

[0031] It is to be understood that the foregoing general description and the following detailed description are exemplary only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0033] Figure 1 It is a three-dimensional schematic diagram showing that an isolating switch part and an earthing switch part of a three-position switch are both in an open state according to an exemplary embodiment.

[0034] Figure 2It is a cross-sectional view showing an isolating switch part and a grounding switch part of a three-position switch in an open state according to an exemplary embodiment.

[0035] Figure 3 It is a cross-sectional view showing a three-position switch with an isolating switch part in a closed state and a grounding switch part in an open state according to an exemplary embodiment.

[0036] Figure 4 It is a cross-sectional view showing a three-position switch with an isolating switch part in an open state and a grounding switch part in a closed state according to an exemplary embodiment. DETAILED DESCRIPTION

[0037] In order to further illustrate the principle and structure of the present disclosure, preferred embodiments of the present disclosure are now described in detail with reference to the accompanying drawings.

[0038] The present disclosure provides a three-position switch, which can be used in a ring network cabinet. The ring network cabinet includes a housing, which is divided into multiple compartments, such as a low-voltage chamber, a mechanism chamber, a gas box, and a cable chamber. The ring network cabinet also includes a circuit breaker switch arranged in the gas box, a three-position switch, and a three-position operating mechanism arranged in the mechanism chamber. The gas box is filled with insulating gas, and the insulating gas can be, for example, sulfur hexafluoride gas. The three-position operating mechanism drives the three-position switch to operate to achieve grounding, opening, or isolation, opening.

[0039] like Figure 1 As shown, the present disclosure provides a three-position switch 100, which includes at least one switch unit 10 and a mechanism input shaft 20. The mechanism input shaft 20 is connected to a three-position operating mechanism located in a mechanism chamber, and rotates clockwise or counterclockwise around itself under the drive of the three-position operating mechanism.

[0040] The three-position switch 100 can be used in a three-phase current switch device. Figure 1 As shown, the three-position switch 100 is a switch device for three-phase current, and a switch unit 10 is provided corresponding to each phase, that is, the three-position switch 100 has three switch units 10. Each switch unit 10 includes a crank plate 11, a grounding contact 12, an insulating connecting plate 13 and a moving contact 14. The grounding contact 12 and the moving contact 14 of each switch unit 10 are arranged on the same mechanism input shaft 20 through their respective crank plates 11, and both move under the drive of the mechanism input shaft 20. Each crank plate 11 is arranged on the mechanism input shaft 20 at intervals.

[0041] The crank arm plate 11 has an opening for the mechanism input shaft 20 to pass through. The crank arm plate 11 is fixedly connected to the mechanism input shaft 20 by welding and can rotate with the mechanism input shaft 20. The crank arm plate 11 has a first end 11a and a second end 11b.

[0042] The crank arm plate 11 is a plate-like structure with one end being large and the other end being small. The crank arm plate 11 may also be a double-layer plate structure. One end of the grounding contact 12 is clamped between the two layers of the first end 11a of the crank arm plate 11 and fixed by a fastener. The fastener may be a connecting bolt or a screw, etc. One end of the insulating connecting plate 13 is clamped between the two layers of the second end 11b of the crank arm plate 11 and connected by a pin 111. The insulating connecting plate 13 can swing around the pin 111 relative to the crank arm plate 11. An angle is formed between the insulating connecting plate 13 and the crank arm plate 11, and the angle changes with the rotation of the mechanism input shaft 20.

[0043] The area of ​​the first end 11a of the crank arm plate 11 is larger than the area 11b of the second end, and the area of ​​the crank arm plate 11 gradually decreases from the first end 11a to the second end 11b. The pin 111 at the connection between the crank arm plate 11 and the insulating connecting plate 13 is in the same straight line as the mechanism input shaft 20, and the connection point between the first end 11a of the crank arm plate 11 and the grounding contact 12 deviates from the straight line. The distance from the connection point of the crank arm plate 11 and the grounding contact 12 to the mechanism input shaft 20 is smaller than the distance from the connection point of the crank arm plate 11 and the insulating connecting plate 13 to the mechanism input shaft 20.

[0044] The lever arm plates 13 of the corresponding switch units 10 are all connected to the mechanism input shaft 20 .

[0045] The grounding contact 12 includes a vertical portion and a horizontal portion. The vertical portion is connected to the crank arm plate 11 and rotates under the drive of the crank arm plate 11. The vertical portion is connected to the grounding bus 18. The grounding bus 18 is connected to the housing of the ring main unit through a flexible connection, thereby forming a reliable grounding. Figure 1 As shown, the three-position switch has three grounding contacts 12 , and the transverse portion of each grounding contact 12 is connected to a grounding busbar 18 .

[0046] As mentioned above, one end of the insulating connecting plate 13 is connected to the second end 11b of the crank arm plate 11, and the other end of the insulating connecting plate 13 is connected to the moving contact 14 through a pin shaft 143. The first end 141 of the moving contact 14 is movably connected to the moving contact seat 15. A fixed frame (not shown) is fixed on the inner wall of the gas box of the ring network cabinet, and the fixed frame includes a plurality of supports. The moving contact seat 15 is fixed on one of the supports of the fixed frame. The second end 142 of the moving contact 14 is a free end. The connection point between the moving contact 14 and the insulating connecting plate 13 is located between the first end 141 and the second end 142 of the moving contact 14. Optionally, the connection point between the moving contact 14 and the insulating connecting plate 13 is located in the middle position of the moving contact 14 or in an area close to the middle position.

[0047] The insulating connecting plate 13 and the moving contact 14 are both in the shape of long strips. Optionally, the insulating connecting plate 13 and the moving contact 14 can also be a double-layer plate structure.

[0048] The insulating connecting plate 13 forms an I-shape with the elbow plate 11 and the moving contact 14, and the insulating connecting plate 13 can be twisted relative to the elbow plate 11 and the moving contact 14, that is, the angle between the insulating connecting plate 13 and the elbow plate 11 and the moving contact 14 is variable.

[0049] The switch unit 10 further includes an isolating static contact 16, which is fixed to an isolating contact seat 17, which is fixed to another support of the fixed frame, and the isolating contact seat 17 and the moving contact seat 15 can be located on the same vertical plane of the gas box, and the moving contact seat 15 is located below the isolating contact seat 17. In addition, the isolating contact seat 17 and the moving contact seat 15 can also be located on the bottom surface of the gas box or on different sides of the gas box.

[0050] The second end 142 of the moving contact 14 can be electrically connected to or separated from the isolating static contact 16 under the drive of the mechanism input shaft 20. The isolating static contact 16 is located on the path of the moving contact 14 rotating in a first direction (for example, clockwise), and the grounding contact 12 is located on the path of the moving contact 13 rotating in a second direction (for example, counterclockwise) opposite to the first direction. In this way, when the moving contact 14 rotates around its first end 141 in the first direction and rotates to a certain angle, the second end 142 of the moving contact 14 is electrically connected to the isolating static contact 16; when the moving contact 14 rotates around its first end 141 in the second direction and rotates to a certain angle, the second end 142 of the moving contact 14 is electrically connected to the grounding contact 12, thereby realizing the isolation switch and the grounding switch.

[0051] When the mechanism input shaft 20 rotates, the crank arm plate 11 is driven to rotate, and the crank arm plate 11 drives the grounding contact 12 and the insulating connecting plate 13 to rotate. Under the pull of the insulating connecting plate 13, the moving contact 14 moves in the opposite direction relative to the grounding contact 12. Specifically, Figure 1 and Figure 2 As shown, the three-position switch 100 is in an isolating opening state and a grounding opening state. When the isolating switch part is closed, the mechanism input shaft 20 moves in a first direction (for example, clockwise), the mechanism input shaft 20 drives the crank arm plate 11 to rotate, the first end 11a of the crank arm plate 11 drives the grounding contact 12 to rotate in the first direction, and the second end 11b of the crank arm plate 11 drives the moving contact 14 to rotate around its first end 141 in a second direction opposite to the first direction (for example, counterclockwise) through the insulating connecting plate 13, that is, the second end 142 of the moving contact 14 is pushed by the insulating connecting plate 13 to approach the direction of the isolating static contact 16, and after rotating a certain angle, as shown in FIG. Figure 3 As shown, the second end 142 of the moving contact 14 is in electrical contact with the isolating static contact 16 to achieve isolating closing.

[0052] When the isolating switch is partially opened, the mechanism input shaft 20 rotates in the second direction (i.e., counterclockwise), the live crank arm plate 11 rotates, and the insulating connecting plate 13 drives the moving contact 14 to move in the isolating opening direction. Figure 2 As shown, the disconnector part returns to the open state.

[0053] When the grounding switch part is closed (at this time, the isolating switch part and the grounding part are both in the open state), the mechanism input shaft 20 moves in the second direction (for example, counterclockwise), and the mechanism input shaft 20 drives the crank plate 11 to rotate, and the first end 11a of the crank plate 11 drives the grounding contact 12 to rotate in the second direction, and the second end 11b of the crank plate 11 drives the moving contact 14 to rotate around its first end 141 in the first direction (for example, clockwise) through the insulating connecting plate 13, that is, the second end 142 of the moving contact 14 approaches the grounding contact 12 under the pull of the insulating connecting plate 13, and after rotating a certain angle, as shown in FIG. Figure 4 As shown, the second end 142 of the moving contact 14 is in electrical contact with the grounding contact 12 to achieve grounding closing. Since the grounding contact 12 and the moving contact 14 move relative to each other and move in the grounding closing direction at the same time, the closing speed of the grounding contact 12 and the moving contact 14 is increased, which can effectively reduce the arc burning time, reduce contact ablation, and increase the service life of the product. Compared with the traditional technology of increasing the closing speed by increasing the spring energy and other means of increasing the mechanism operating work, the operating mechanism of the three-position switch and the service life of the three-position switch are increased, and the stability of the product is improved.

[0054] When the grounding switch part is opened, the mechanism input shaft 20 rotates in the first direction (i.e. clockwise), driving the crank arm plate 11 to rotate, and at the same time driving the grounding contact 12 and the moving contact 14 of the crank arm plate 11 to move in the opening direction, that is, the grounding contact 12 rotates clockwise with the mechanism input shaft 20, and the moving contact 14 moves counterclockwise around its first end 141.

[0055] Since the moving contact 14 and the grounding contact 12 are driven to rotate by the same mechanism input shaft 20, it can be ensured that when the moving contact 14 and the isolating static contact 16 are closed, the grounding switch part is in the open state, and when the moving contact 14 and the grounding contact 12 are closed, the isolating switch part is in the open state, effectively preventing live grounding.

[0056] The moving contact 14 and the grounding contact 12 move in opposite directions during the closing and opening process. Here, movement in opposite directions means that the grounding contact 12 and the moving contact 14 move in opposite directions around their respective rotating axes. For example, if the grounding contact 12 moves clockwise around the mechanism input shaft 20, the moving contact 14 moves counterclockwise around its first end 141; if the grounding contact 12 moves counterclockwise around the mechanism input shaft 20, the moving contact 14 moves clockwise around its first end 141. In this way, the grounding contact 12 and the moving contact 14 move relative to each other or move away from each other.

[0057] In summary, the grounding contact and the moving contact of the three-position switch disclosed in the present invention are driven to rotate through the same mechanism input shaft, and drive the grounding contact and the moving contact to move in opposite directions. In this way, while meeting the interlocking requirements of the switching device, the closing speed of the moving contact and the grounding contact can also be accelerated, effectively reducing the arc burning time and reducing contact erosion.

[0058] The above are only preferred feasible embodiments of the present disclosure and are not intended to limit the protection scope of the present disclosure. All equivalent structural changes made using the contents of the present disclosure and the drawings are included in the protection scope of the present disclosure.

Claims

1. A three-position switch, characterized in that: Applied to ring main units, including: A mechanism input shaft, which can be connected to the three-position operating mechanism and rotate under the drive of the three-position operating mechanism; and At least one switch unit, each switch unit comprising: A crank arm plate, fixedly connected to the mechanism input shaft and capable of rotating with the mechanism input shaft, the crank arm plate having a first end and a second end; A grounding contact connected to the first end of the crank arm plate; An insulating connecting plate, one end of which is connected to the second end of the crank arm plate; A moving contact, which is movably connected to the other end of the insulating connecting plate, the first end of the moving contact is movably connected to the moving contact seat, the moving contact seat can be fixed on a fixed frame, the fixed frame is fixed on the inner wall of the gas box of the ring network cabinet, the second end of the moving contact is a free end, and the connection point between the moving contact and the insulating connecting plate is located between the first end of the moving contact and the second end of the moving contact; When the input shaft of the mechanism rotates in the earthing and closing direction, the moving contact and the earthing contact move relative to each other and both move in the closing direction.

2. The three-position switch according to claim 1, characterized in that: The area of ​​the first end of the crank arm plate is larger than the area of ​​the second end.

3. The three-position switch according to claim 2, characterized in that: The area of ​​the crank arm plate gradually decreases from the first end to the second end.

4. The three-position switch according to claim 1, characterized in that: The distance between the connection point between the crank arm plate and the grounding contact and the mechanism input shaft is smaller than the distance between the connection point between the crank arm plate and the insulating connecting plate and the mechanism input shaft; The pin shaft at the connection between the crank arm plate and the insulating connecting plate is in the same straight line as the mechanism input shaft, and the connection point between the first end of the crank arm plate and the grounding contact deviates from the straight line.

5. The three-position switch according to claim 1, characterized in that: The switch unit further comprises an isolating static contact, the isolating static contact is fixed on an isolating contact seat, the isolating contact seat can be fixed on the fixed frame, and the second end of the moving contact can be electrically connected to the grounding contact or to the isolating static contact under the drive of the mechanism input shaft; When the three-position switch is grounded and opened, the mechanism input shaft rotates in a first direction, the first end of the crank arm plate drives the grounding contact to rotate in the first direction, and the second end of the crank arm plate drives the moving contact to rotate in a second direction opposite to the first direction through the insulating connecting plate, so that the grounding contact and the moving contact move in the opening direction at the same time; When the three-position switch is grounded and closed, the mechanism input shaft rotates in the second direction, the first end of the crank arm plate drives the grounding contact to rotate in the second direction, and the second end of the crank arm plate drives the moving contact to rotate in the first direction through the insulating connecting plate, so that the moving contact and the grounding contact move in the closing direction at the same time.

6. The three-position switch according to claim 5, characterized in that: The isolating static contact is located on a path where the moving contact rotates in a first direction, and the grounding contact is located on a path where the moving contact rotates in a second direction.

7. The three-position switch according to claim 1, characterized in that: The moving contact and the insulating connecting plate are both in the shape of long strips, and the connection point between the moving contact and the insulating connecting plate is located in the middle of the moving contact.

8. The three-position switch according to claim 1, characterized in that: The three-position switch also includes a grounding busbar, which is connected to the housing of the ring network cabinet through a flexible connection; The grounding contact is connected to the grounding busbar.

9. The three-position switch according to claim 8, characterized in that: The three-position switch is applied to a switch device for three-phase current, and one switch unit is provided for each phase of current, and the crank plates of each switch unit are arranged at intervals on the input shaft of the mechanism; The grounding contacts of each switch unit are connected to the grounding busbar.

10. A ring main unit, characterized in that: It comprises an air box, a three-position switch as claimed in any one of claims 1 to 9 arranged inside the air box, and a three-position operating mechanism arranged in a mechanism chamber; A fixed frame is installed on the inner wall of the gas box, the moving contact seat of the three-position switch is fixed on the fixed frame, and the gas box is filled with insulating gas; The three-position operating mechanism is connected to the mechanism input shaft of the three-position switch and can drive the mechanism input shaft to rotate.

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