Switch for medium-voltage or high-voltage switchgear

Abstract

The invention relates to a switch for a medium-voltage or high-voltage switchgear. The switch includes a first fixed contact, a second fixed contact, a movable contact, at least one bendable connector, and a contact drive. In an on state of the switch, the movable contact is in a position connecting the first fixed contact to the second fixed contact. In an off state of the switch, the movable contact is in a position where the first fixed contact is not connected to the second fixed contact. At least one bendable connector is connected to the movable contact. At least one bendable connector is in driving engagement with the contact. The contact drive is configured to pull the movable contact via the at least one bendable connector, and the contact drive is configured to push the movable contact via the at least one bendable connector. In a first mode, activation of the contact drive is configured to move the movable contact to a position such that the switch is in an on state. In a second mode, activation of the contact drive is configured to move the movable contact to a position such that the switch is in an off state.

Description

[0001] This invention application is a divisional application of the invention application with an international application date of February 18, 2020, an international application number of PCT / EP2020 / 054209, a national application number of 202080015017.8 entering the Chinese national phase, and an invention name of “Switch for medium-voltage or high-voltage switchgear”. Technical Field

[0002] The invention relates to a switch for use as a two-position or three-position switch in an air-insulated or gas-insulated switchgear for medium-voltage or high-voltage applications. Background Art

[0003] The contact system of a two-position or three-position disconnector for a switchgear is actuated by different technologies, including, for example, levers, spindles, push rods, in order to move the switch to each of its terminal positions. The task is to move the switch to a specific position and keep it in its position under load of the rated current and during the flow of a short-circuit current. However, lever-based actuation usually produces a discontinuous transmission, while spindle-based actuation does not show the same degree of discontinuity, but is only effective for a few rotations, and the threads that need to be produced on the bolts and nuts require high precision and are therefore expensive. In addition, push rod-based actuation requires a lot of space for the actuation movement.

[0004] There is a need to address these issues. Summary of the invention

[0005] It would therefore be advantageous to have an improved two-position or three-position switch for medium voltage or high voltage switchgear.

[0006] The objects of the invention are solved by the subject-matter of the independent claims, wherein further embodiments are incorporated in the dependent claims.

[0007] In a first aspect, there is provided a switch for a medium voltage or high voltage switchgear, the switch comprising:

[0008] - a first fixed contact;

[0009] - a second fixed contact;

[0010] - movable contacts;

[0011] - at least one bendable connector; and

[0012] -Contact drive.

[0013] In the on-state of the switch, the movable contact is in a position connecting the first fixed contact to the second fixed contact. In the off-state of the switch, the movable contact is in a position where the first fixed contact is not connected to the second fixed contact. At least one bendable connection is connected to the movable contact. At least one bendable connection is engaged with a contact drive. The contact drive is configured to pull the movable contact via at least one bendable connection, and the contact drive is configured to push the movable contact via at least one bendable connection. In a first mode, activation of the contact drive is configured to move the movable contact to a position that causes the switch to be in the on-state. In a second mode, activation of the contact drive is configured to move the movable contact to a position that causes the switch to be in the off-state.

[0014] In this way, an actuating element is provided that utilizes a flexible link to enable continuous transmission from one state to another (providing on-off and off-on) and in which less space is required because the flexible link can coil or fold when pulled.

[0015] In an example, the switch includes a fixed grounding contact. In a grounded state of the switch, the movable contact is configured to be in a position connecting the second fixed contact to the grounded fixed contact. In a third mode, activation of the contact drive is configured to move the movable contact to a position that causes the switch to be in the grounded state.

[0016] Thus, two-position and three-position switches for medium and high voltage switchgear are enabled.

[0017] In an example, the switch includes a connector guide. At least a portion of the at least one bendable connector is configured to travel within or near the connector guide in a longitudinal direction. The connector guide is configured to inhibit the at least one bendable connector from bending in a direction perpendicular to the longitudinal direction.

[0018] In this way, the connector guide, which prevents deformation of the bendable connector in at least one direction, enables high axial forces to be applied during push actuation as well as pull actuation.

[0019] In an example, the contact drive includes at least one gear configured to engage with the at least one flexible link.

[0020] In this way a simple mechanism is provided for pulling and pushing the bendable connector by rotation of a gear, for example having teeth in the form of a chain or notches or ridges engaging the bendable connector in the form of a toothed belt.

[0021] In an example, rotation of a gear of the at least one gear in a first direction is configured to pull the bendable connection, and rotation of the gear in a direction opposite to the first direction is configured to push the bendable connection.

[0022] In an example, the at least one bendable connector is two bendable connectors.

[0023] In this way, bendable connector guides may not be required as the bendable connector may be configured to resist bending when pushed as well as when pulled.

[0024] In an example, the at least one gear is two gears.

[0025] In an example, rotation of a first gear of the two gears in a first direction is configured to pull the first bendable connector of the two bendable connectors, and rotation of a second gear of the two gears in a second direction opposite to the first direction is configured to pull the second bendable connector of the two bendable connectors. In addition, rotation of the first gear of the two gears in the second direction is configured to push the first bendable connector of the two bendable connectors, and rotation of the second gear of the two gears in the first direction is configured to push the second bendable connector of the two bendable connectors.

[0026] In other words, two bendable connectors are provided back to back. Thus, bendable connectors in the form of a push chain that resist bending in one direction but can bend in other directions can be placed back to back so that they resist bending outwardly away from each other. Then, during pushing, they form a single bendable connector that resists bending and can apply high axial forces, and similarly can apply high axial forces when pulling, and can still be folded or coiled into two sets of folded or coiled bendable connectors.

[0027] In an example, the at least one bendable connector comprises at least one chain.

[0028] In an example, at least one chain comprises a push chain.

[0029] In an example, when extending in the longitudinal axis, the push chain is configured to enable the chain to bend out of the axis in a first direction perpendicular to the axis and is configured to resist bending of the chain out of the axis in a second direction opposite to the first direction.

[0030] In an example, the at least one bendable connection comprises at least one toothed belt.

[0031] In an example, the switch is configured to switch between the second mode and the third mode without entering the first mode.

[0032] Thus, the switch can move from the OFF state to the ground state, and vice versa, without entering the ON state.

[0033] In an example, the at least one gear is configured to rotate less than one revolution when the switch is switched between the second mode and the third mode.

[0034] In this way, a two-position or three-position switch is provided, wherein actuation is facilitated by less than one rotation of the gears.

[0035] In an example, the contact actuation is configured to pull the at least one bendable link to transition from the second mode to the third mode.

[0036] In an example, the contact drive is configured to push the at least one flexible link to switch from the third mode to the second mode.

[0037] In an example, the switch is configured to switch between the second mode and the first mode without entering the third mode.

[0038] Thus, the switch can be moved from the OFF state to the ON state, and vice versa, without entering the ground state.

[0039] In an example, the at least one gear is configured to rotate less than one revolution when the switch is switched between the second mode and the first mode.

[0040] In this way, a two-position or three-position switch is provided, wherein actuation is facilitated by less than one rotation of the gears.

[0041] In an example, the contact drive is configured to push the at least one flexible link to switch from the second mode to the first mode.

[0042] In an example, the contact actuation is configured to pull the at least one bendable link to transition from the first mode to the second mode.

[0043] In an example, the switch includes a compartment configured to accommodate a length of at least one bendable link when the contact is actuated to pull the at least one bendable link. A maximum interior dimension of the compartment is less than the length of the at least one bendable link.

[0044] In this way, space is saved since the bendable connection can be coiled or folded as required.

[0045] In a second aspect, a medium voltage or high voltage switchgear is provided, comprising at least one switch according to the first aspect.

[0046] The above aspects and examples will be apparent from and elucidated with reference to the embodiments described hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Exemplary embodiments will be described below with reference to the following drawings:

[0048] Figure 1 An example of a switch is shown;

[0049] Figure 2 An example of a switch is shown;

[0050] Figure 3 An example of a switch is shown;

[0051] Figure 4 A portion of an example of a switch is shown;

[0052] Figure 5 shows a portion of an example of a switch; and

[0053] Figure 6 A compartment of a medium or high voltage switchgear with three switch examples is shown. DETAILED DESCRIPTION

[0054] Figures 1 to 6 A switch for medium voltage or high voltage switchgear is disclosed. In an example, the switch comprises a first fixed contact, a second fixed contact, a movable contact, at least one flexible connection and a contact drive. In the on state of the switch, the movable contact is in a position connecting the first fixed contact to the second fixed contact. In the off state of the switch, the movable contact is in a position where the first fixed contact is not connected to the second fixed contact. At least one flexible connection is connected to the movable contact. At least one flexible connection is engaged with the contact drive. The contact drive is configured to pull the movable contact via at least one flexible connection. The contact drive is also configured to push the movable contact via at least one flexible connection. In a first mode, activation of the contact drive is configured to move the movable contact to a position where the switch is in the on state. In a second mode, activation of the contact drive is configured to move the movable contact to a position where the switch is in the off state.

[0055] In an example, the on state involves that electric current can flow from the first fixed contact to the second fixed contact via the movable contact.

[0056] In an example, in the off state, the movable contact is configured to be substantially located within the second fixed contact.

[0057] In an example, the first fixed contact is a disconnector contact.

[0058] In an example, the second stationary contact is a center contact.

[0059] According to an example, the switch comprises a fixed grounding contact. In a grounded state of the switch, the movable contact is configured to be in a position connecting the second fixed contact to the grounded fixed contact. In a third mode, activation of the contact drive is configured to move the movable contact to a position such that the switch is in the grounded state.

[0060] According to an example, the switch includes a connector guide. At least a portion of at least one bendable connector is configured to travel in or near the connector guide in a longitudinal direction. The connector guide is configured to inhibit or resist bending of at least one bendable connector in a direction perpendicular to the longitudinal direction.

[0061] In an example, the connector guide is located on only one side of the bendable connector.

[0062] In an example, the connector guides are located on at least opposite sides of the bendable connector.

[0063] According to an example, the contact drive comprises at least one gear configured to engage with the at least one flexible link.

[0064] According to an example, rotation of a gear of the at least one gear in a first direction is configured to pull the bendable connector. Then, rotation of the gear in a direction opposite to the first direction is configured to push the bendable connector.

[0065] According to an example, the at least one bendable connection is two bendable connections.

[0066] According to an example, the at least one gear wheel is two gear wheels.

[0067] According to an example, the rotation of the first gear of the two gears in the first direction is configured to pull the first bendable connector of the two bendable connectors, and the rotation of the second gear of the two gears in the second direction opposite to the first direction is configured to pull the second bendable connector of the two bendable connectors. Then, the rotation of the first gear of the two gears in the second direction is configured to push the first bendable connector of the two bendable connectors, and the rotation of the second gear of the two gears in the first direction is configured to push the second bendable connector of the two bendable connectors.

[0068] According to an example, the at least one bendable connection comprises at least one chain.

[0069] According to an example, the at least one chain comprises a push chain.

[0070] According to an example, when extending on the longitudinal axis, the push chain is configured to enable the chain to bend out of the axis in a first direction perpendicular to the axis and to resist bending of the chain out of the axis in a second direction opposite to the first direction.

[0071] According to an example, the at least one bendable connection comprises at least one toothed belt.

[0072] According to an example, the switch is configured to switch between the second mode and the third mode without entering the first mode.

[0073] According to an example, the at least one gear is configured to rotate less than one revolution when the switch is switched between the second mode and the third mode.

[0074] According to an example, the contact drive is configured to pull the at least one bendable link to switch from the second mode to the third mode.

[0075] According to an example, the contact drive is configured to push the at least one bendable link to switch from the third mode to the second mode.

[0076] According to an example, the switch is configured to switch between the second mode and the first mode without entering the third mode.

[0077] According to an example, the at least one gear is configured to rotate less than one revolution when the switch is switched between the second mode and the first mode.

[0078] In an example, at least one gear is configured to rotate less than one turn when the switch is switched between the first mode and the third mode. Thus, via less than one turn of the actuating gear, the switch can move from the on state to the ground state through the off state.

[0079] According to an example, the contact drive is configured to push the at least one bendable link to switch from the second mode to the first mode.

[0080] According to an example, the contact drive is configured to pull the at least one bendable link to switch from the first mode to the second mode.

[0081] According to an example, the switch includes a compartment configured to accommodate the length of at least one bendable link when the contact is actuated to pull the at least one bendable link. The maximum interior dimension of the compartment is less than the length of the at least one bendable link residing in the compartment.

[0082] Thus, the switch described in any of the above examples may be used in medium voltage or high voltage switchgear.

[0083] Therefore, specific detailed embodiments will now be described with respect to the accompanying drawings. A push chain of the switch is attached or connected to a moving or movable contact. The push chain engages with a gear and is partially wrapped around the gear, wherein the teeth of the gear extend into and through the chain. Therefore, rotation of the gear is required to pull or push the push chain. Here, the push chain is a chain that is resistant to bending on one side and flexible on the other side. The switch also has an isolating switch contact at one end, an intermediate contact in the center, and an earth contact at the end closest to the gear. The gear forms part of the contact drive, with a motor and control electronics not shown. A chain guide is provided, which is Figure 4 As described above, the push chain can bend in one direction but resists bending in the other direction, and the chain guide is provided on the side where the push chain can bend. Therefore, in case a chain guide is provided, the push chain cannot bend. In this way, by using the guide, the push chain can transmit high forces in the longitudinal direction via a push-pull system actuated by a sprocket or gear. Figure 1 As shown in , the gear rotates in the counterclockwise direction, and the push chain pushes the movable contact to the left until it connects the disconnector contact with the middle contact, at which point the disconnector is in the on position. Figure 2 As shown in , the rotation of the gear in the clockwise direction pulls the push chain, causing the movable contact to be pulled into the position inside the middle contact, resulting in the disconnector being closed and the earthing being disconnected. Figure 3 As shown in , further rotation of the gear in the clockwise direction pulls the push chain, causing the movable contact to be pulled to a position where the movable contact connects the intermediate contact to the grounding contact, resulting in a grounding-on position. Then, rotation of the gear in the counterclockwise direction can push the movable contact from the grounding-on position to the disconnector-off and grounding-off position, wherein further rotation in the counterclockwise direction causes the movable contact to be pushed to the disconnector-on position.

[0084] Behind the sprocket or gear, the chain can be folded in the space provided and no more space is required. One advantage is to have an actuating element that can actuate the contact system with less than one rotation, which has the advantage of providing a continuous transmission with less space requirements. A further advantage is that the drive is independent of the position of the contact system with respect to the orientation (horizontal, vertical, diagonal). Furthermore, the connection of the push chain to the movable contact is relatively simple. Furthermore, by using a push chain, actuation can be facilitated by only one mechanical bushing, resulting in fewer components and resulting in a smaller risk of leakage during actuation.

[0085] It should be noted that instead of a push chain, a drive belt could be used, but this would likely require additional mechanical support.

[0086] Furthermore, instead of using a push chain, two chains or two toothed belts can be used. Figure 5 , where the push chains are used back to back, where they can only bend towards each other and therefore as a pair cannot bend when placed back to back, but can still bend behind the gear and be stored in a space-saving manner. However, two chains acting in this way can still pull and push the movable contact with great force, and in this case no chain guide is required, although it is obvious that a chain guide can still be utilized.

[0087] Figure 6 An example of three switches in a compartment of a medium voltage or high voltage switchgear is shown, wherein the three switches are shown in an earthed-on state.

[0088] Although the present invention has been illustrated and described in the drawings and the foregoing description, such illustration and description should be considered illustrative or exemplary rather than restrictive. The present invention is not limited to the disclosed embodiments. Other variations of the disclosed embodiments may be understood and effected by those skilled in the art in practicing the claimed invention by studying the drawings, the disclosure, and the dependent claims.

[0089] This disclosure provides the following examples:

[0090] Example 1: A switch for medium voltage or high voltage switchgear, the switch comprising:

[0091] - a first fixed contact;

[0092] - a second fixed contact;

[0093] - movable contacts;

[0094] - at least one bendable connector; and

[0095] -Contact drive;

[0096] wherein in the on state of the switch, the movable contact is in a position to connect the first fixed contact to the second fixed contact;

[0097] wherein in the off state of the switch, the movable contact is in a position where the first fixed contact is not connected to the second fixed contact;

[0098] wherein at least one of the bendable connectors is connected to the movable contact;

[0099] wherein the at least one flexible link is engaged with a contact drive, and wherein the contact drive is configured to pull the movable contact via the at least one flexible link, and wherein the contact drive is configured to push the movable contact via the at least one flexible link;

[0100] wherein in the first mode, activation of the contact drive is configured to move the movable contact to a position such that the switch is in an on state; and

[0101] Wherein in the second mode, activation of the contact drive is configured to move the movable contact to a position such that the switch is in an off state.

[0102] Example 2: According to the switch of Example 1, the switch includes a fixed grounding contact; wherein in the grounded state of the switch, the movable contact is configured to be in a position connecting the second fixed contact to the grounded fixed contact; and wherein in a third mode, activation of the contact drive is configured to move the movable contact to a position that causes the switch to be in the grounded state.

[0103] Example 3: A switch according to any of Examples 1 to 2, wherein the switch includes a connector guide; wherein at least a portion of at least one bendable connector is configured to travel within or near the connector guide in a longitudinal direction; and wherein the connector guide is configured to inhibit at least one bendable connector from bending in a direction perpendicular to the longitudinal direction.

[0104] Example 4: The switch of any of Examples 1 to 3, wherein the contact drive comprises at least one gear, the at least one gear being configured to engage with the at least one flexible link.

[0105] Example 5: The switch of Example 4, wherein rotation of a gear of at least one gear in a first direction is configured to pull the bendable connection, and wherein rotation of the gear in a direction opposite to the first direction is configured to push the bendable connection.

[0106] Example 6: The switch of any of Examples 4 to 5, wherein the at least one bendable connection is two bendable connections.

[0107] Example 7: The switch of Example 6, wherein the at least one gear is two gears.

[0108] Example 8: A switch according to Example 7, wherein rotation of a first gear of the two gears in a first direction is configured to pull the first bendable connector of the two bendable connectors, and rotation of a second gear of the two gears in a second direction opposite to the first direction is configured to pull the second bendable connector of the two bendable connectors, and rotation of the first gear of the two gears in the second direction is configured to push the first bendable connector of the two bendable connectors, and rotation of the second gear of the two gears in the first direction is configured to push the second bendable connector of the two bendable connectors.

[0109] Example 9: The switch of any of Examples 1 to 8, wherein the at least one bendable link comprises at least one chain.

[0110] Example 10: The switch of Example 9, wherein at least one chain comprises a push chain.

[0111] Example 11: The switch of Example 10, wherein when extending in the longitudinal axis, the push chain is configured to enable the chain to bend out of the axis in a first direction perpendicular to the axis, and is configured to resist bending of the chain out of the axis in a second direction opposite to the first direction.

[0112] Example 12: The switch of any of Examples 1 to 8, wherein the at least one bendable link comprises at least one toothed belt.

[0113] Example 13: The switch of any of Examples 2 to 12, wherein the switch is configured to switch between the second mode and the third mode without entering the first mode.

[0114] Example 14: The switch according to Example 13 when dependent on Example 4, or any one of Examples 5 to 12 when dependent on Example 4, wherein at least one gear is configured to rotate less than one revolution when the switch is switched between the second mode and the third mode.

[0115] Example 15: The switch of any of Examples 2 to 14, wherein the contact actuation is configured to pull the at least one bendable link to switch from the second mode to the third mode.

[0116] Example 16: The switch of any of Examples 2 to 15, wherein the contact actuation is configured to push the at least one flexible link to switch from the third mode to the second mode.

[0117] Example 17: The switch of any of Examples 1 to 16, wherein the switch is configured to switch between the second mode and the first mode without entering the third mode.

[0118] Example 18: The switch according to Example 17 when dependent on Example 4, or any one of Examples 5 to 16 when dependent on Example 4, wherein at least one gear is configured to rotate less than one revolution when the switch is switched between the second mode and the first mode.

[0119] Example 19: The switch of any of Examples 1 to 18, wherein the contact actuation is configured to push the at least one flexible link to switch from the second mode to the first mode.

[0120] Example 20 The switch of any of Examples 1 to 19, wherein the contact actuation is configured to pull the at least one bendable link to switch from the first mode to the second mode.

[0121] Example 21: A switch according to any one of Examples 1 to 20, wherein the switch includes a compartment configured to accommodate the length of at least one bendable connection when the contact drives the at least one bendable connection, wherein the maximum internal dimension of the compartment is less than the length of the at least one bendable connection.

[0122] Example 22: A medium voltage or high voltage switchgear comprising at least one switch according to any one of Examples 1 to 21.

Claims

1. A switch for a medium voltage or high voltage switchgear, the switch comprising: - a first fixed contact; - a second fixed contact; - movable contacts; - at least one bendable connection element; as well as -Contact drive; wherein in the on state of the switch, the movable contact is in a position to connect the first fixed contact to the second fixed contact; wherein in the off state of the switch, the movable contact is in a position where the first fixed contact is not connected to the second fixed contact; wherein the at least one bendable connector is connected to the movable contact; wherein the at least one bendable link is engaged with the contact drive, and wherein the contact drive is configured to pull the movable contact via the at least one bendable link, and wherein the contact drive is configured to push the movable contact via the at least one bendable link; wherein the contact drive comprises at least one gear, the at least one gear being configured to engage the at least one bendable connector, and wherein rotation of a gear of the at least one gear in a first direction is configured to pull the bendable connector, and wherein rotation of the gear in a direction opposite to the first direction is configured to push the bendable connector; wherein the at least one bendable connector comprises at least one chain, wherein the at least one chain comprises a push chain, wherein when extending in a longitudinal axis, the push chain is configured to enable the chain to bend out of the axis in a first direction perpendicular to the axis and configured to resist bending of the chain out of the axis in a second direction opposite to the first direction; wherein in a first mode, activation of the contact drive is configured to move the movable contact to the position causing the switch to be in the on state; and Wherein in the second mode, activation of the contact drive is configured to move the movable contact to the position that causes the switch to be in the off state.

2. The switch of claim 1 , comprising a fixed grounding contact; wherein in a grounded state of the switch, the movable contact is configured to be in a position connecting the second fixed contact to the grounded fixed contact; and wherein in a third mode, activation of the contact drive is configured to move the movable contact to the position causing the switch to be in the grounded state.

3. The switch of any one of claims 1 to 2, wherein the switch comprises a connector guide; wherein at least a portion of the at least one bendable connector is configured to travel within or near the connector guide in a longitudinal direction; and wherein the connector guide is configured to inhibit the at least one bendable connector from bending in a direction perpendicular to the longitudinal direction.

4. The switch according to any one of claims 1 to 3, wherein the at least one bendable connection is two bendable connections. The switch of claim 4 , wherein the at least one gear is two gears.

6. The switch of claim 5, wherein rotation of the first of the two gears in a first direction is configured to pull the first of the two bendable connectors, and rotation of the second of the two gears in a second direction opposite to the first direction is configured to pull the second of the two bendable connectors, and rotation of the first of the two gears in the second direction is configured to push the first of the two bendable connectors, and rotation of the second of the two gears in the first direction is configured to push the second of the two bendable connectors.

7. The switch according to any one of claims 2 to 6, wherein the switch is configured to switch between the second mode and the third mode without entering the first mode.

8. The switch of claim 7, wherein the at least one gear is configured to rotate less than one revolution when the switch is switched between the second mode and the third mode.

9. The switch according to any one of claims 2 to 8, wherein the contact drive is configured to pull the at least one bendable link to switch from the second mode to the third mode.

10. The switch according to any one of claims 2 to 9, wherein the contact drive is configured to push the at least one bendable link to switch from the third mode to the second mode.

11. The switch according to any one of claims 1 to 10, wherein the switch is configured to switch between the second mode and the first mode without entering the third mode.

12. The switch of claim 11, wherein the at least one gear is configured to rotate less than one revolution when the switch is switched between the second mode and the first mode.

13. The switch according to any one of claims 1 to 12, wherein the contact drive is configured to push the at least one bendable link to switch from the second mode to the first mode.

14. The switch according to any one of claims 1 to 13, wherein the contact drive is configured to pull the at least one bendable link to switch from the first mode to the second mode.

15. A switch according to any one of claims 1 to 14, wherein the switch comprises a compartment configured to accommodate the length of the at least one bendable link when the contact is driven to pull the at least one bendable link, wherein the maximum internal dimension of the compartment is less than the length of the at least one bendable link.

16. A medium voltage or high voltage switchgear comprising at least one switch according to any one of claims 1 to 15.

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