Three-position disconnecting switch

Abstract

The present invention relates to a three-position disconnect switch, comprising: a power input contact; a piston; a power output contact; a plurality of flexible locking elements; a grounding contact; and a threaded rod. The piston includes an internal threaded section configured to engage with the threaded rod, and rotation of the threaded rod is configured to engage with the internal threaded section to move the piston along the axis of the switch between different switch positions. The piston includes a groove extending in a direction parallel to the axis. Each flexible locking element is configured such that when the piston moves along the axis of the switch between different switch positions, a portion of each flexible locking element among the flexible locking elements moves into and out of the groove as the piston moves along the axis in two directions. When the piston moves along the axis, the switch is configured such that a portion of at least one flexible locking element is always located in the groove. When a portion of at least one flexible locking element is located in the groove, the piston is constrained to rotate about the axis.

Description

Technical Field

[0001] The present invention relates to a three - position disconnector and switching or control equipment for low - voltage, medium - voltage or high - voltage use together with a substation. Background Art

[0002] Three - position disconnectors are used as standard to disconnect a panel from the main busbar or connect it to ground. For this purpose, linear three - position disconnectors can be used. Such disconnectors can be advanced or moved in several different ways and can have a variety of different shapes. Circular types can be pushed by screws and offer many advantages, but must be locked against rotational movement. The way to achieve this can vary.

[0003] If a linear three - position disconnector is pushed by a screw, the piston of the disconnector is subject not only to a linear force but also to a torque. Rotation of the piston itself is not desired and should be eliminated, otherwise it cannot be determined whether the piston always reaches its desired position. Therefore, the rotation of the threaded rod should be completely converted into linear movement of the piston. Ideally, this should be done in a way that does not make the three - position disconnector larger than required from the perspective of temperature rise and dielectric. However, this is difficult to achieve.

[0004] This problem must be solved. Summary of the Invention

[0005] Therefore, it may be advantageous to have an improved three - position disconnector.

[0006] The object of the present invention is solved by the subject matter of the independent claims, with other embodiments incorporated into the dependent claims.

[0007] In a first aspect, there is provided a three - position disconnector, comprising:

[0008] - a power input contact;

[0009] - a piston;

[0010] - a power output contact;

[0011] - a plurality of flexible locking elements;

[0012] - a ground contact; and

[0013] - a threaded rod.

[0014] The length of the piston is such that in the first switch position, the outer surface of the wall of the piston forms an electrical contact between the power input contact and the power output contact. The length of the piston is such that in the second switch position, the outer surface of the wall of the piston is not in electrical contact with the ground contact or the power input contact. In the second switch position, the outer surface of the wall of the piston is in electrical contact with the power output contact. The length of the piston is such that in the third switch position, the outer surface of the wall of the piston forms an electrical contact between the ground contact and the power output contact. The piston includes an internal threaded section configured to engage with a threaded rod, and rotation of the threaded rod is configured to engage with the internal threaded section to move the piston between different switch positions along the axis of the switch. The piston includes a groove extending in a direction parallel to the axis. Each of the flexible locking elements is configured such that when the piston is moved along the axis of the switch between different switch positions, a portion of each of the flexible locking elements moves into and out of the groove as the piston moves along the axis in both directions. When the piston is moved along the axis, the switch is configured such that a portion of at least one of the flexible locking elements is always located in the groove. When a portion of at least one of the flexible locking elements is located in the groove, the piston is constrained from rotating about the axis.

[0015] In an example, each of the plurality of flexible locking elements is non-conductive.

[0016] In an example, the power output contact includes a first portion and a second portion. The first portion is electrically connected to the second portion. In the first switch position, the outer surface of the wall of the piston is in direct electrical contact with the first portion of the power output contact and in direct electrical contact with the power input contact. In the second switch position, the outer surface of the wall of the piston is in direct electrical contact with the first portion of the power output contact and in direct electrical contact with the second portion of the power output contact. In the third switch position, the outer surface of the wall of the piston is in direct electrical contact with the second portion of the power output contact and in direct electrical contact with the ground contact.

[0017] Thus, the intermediate power output contact is made of two portions that are electrically connected to each other. This results in a reduction in the overall length of the disconnect switch as compared to a disconnect switch having only one intermediate power output contact.

[0018] In an example, the first flexible locking element is connected to the power output contact and is located on a side of the power output contact facing the power input contact; and the second flexible locking element is connected to the power output contact and is located on a side of the power output contact facing the ground contact.

[0019] In the example, in the first switch position, a portion of the first flexible locking element is located in the groove. In the second switch position, a portion of the first flexible locking element is located in the groove, and a portion of the second flexible locking element is located in the groove. In the third switch position, a portion of the second flexible locking element is located in the groove.

[0020] In the example, in the first switch position, a portion of the second flexible locking element is not located in the groove. In the third switch position, a portion of the first flexible locking element is not located in the groove.

[0021] In other words, the switch may have an intermediate contact or a power output contact in the form of only one contact, with flexible locking elements protruding from either side of the contact.

[0022] In the example, the first flexible locking element is connected to the first part of the power output contact and is located on the side of the first part of the power output contact facing the power input contact; and the second flexible locking element is connected to the second part of the power output contact and is located on the side of the second part of the power output contact facing the ground contact. In the first switch position, a portion of the first flexible locking element is located in the groove.

[0023] In other words, the disconnect switch has an intermediate power output contact with two contact parts, and the flexible locking elements on each part face away from each other and face outwards.

[0024] In the example, in the first switch position, a portion of the second flexible locking element is not located in the groove.

[0025] In the example, the third flexible locking element is connected to the first part of the power output contact and is located on the side of the first part of the power output contact facing the ground contact; and the fourth flexible locking element is connected to the second part of the power output contact and is located on the side of the second part of the power output contact facing the power input contact. In the second switch position, a portion of the third flexible locking element is located in the groove; and in the second switch position, a portion of the fourth flexible locking element is located in the groove.

[0026] Thus, the circuit breaker arrangement has an intermediate power output connector that has two parts, and flexible locking elements are located on both sides of each part.

[0027] In this way, a portion of at least one locking element may always be located in the groove, while minimizing the length of the piston and the length of the groove.

[0028] In the example, the first flexible locking element is connected to the second part of the power output contact and is located on the side of the second part of the power output contact facing the power input contact; and the second flexible locking element is connected to the first part of the power output contact and is located on the side of the first part of the power output contact facing the ground contact. In the second switch position, a portion of the first flexible locking element is located in the groove, and a portion of the second flexible locking element is located in the groove.

[0029] In other words, the disconnect switch has an intermediate power output contact with two contact parts, and the flexible locking elements on each part face inward toward each other.

[0030] In the example, the third flexible locking element is connected to the power input contact and is located on the side of the power input contact facing the ground contact; and the fourth flexible locking element is connected to the ground contact and is located on the side of the ground contact facing the power input contact. In the first switch position, a portion of the third flexible locking element is located in the groove; and in the third switch position, a portion of the fourth flexible locking element is located in the groove.

[0031] Thus, the power input connector and the ground connector also have flexible locking elements facing inward.

[0032] In this way, a portion of at least one locking element may always be located in the groove, while minimizing the length of the piston and the length of the groove.

[0033] In the example, in the first switch position, a portion of the second flexible locking element is not located in the groove; and in the third switch position, a portion of the first flexible locking element is not located in the groove.

[0034] In the example, the groove does not extend to the first distal end of the piston, and optionally, the groove does not extend to the second distal end of the piston opposite the first distal end.

[0035] Thus, the tips or corners do not compromise the dielectric performance.

[0036] In the example, the plurality of flexible locking elements are configured to flex.

[0037] In a second aspect, there is provided a low-voltage, medium-voltage, high-voltage switchgear or control device including one or more three-position disconnect switches according to the first aspect.

[0038] The above aspects and examples will become apparent from the embodiments described below and will be elucidated with reference to the embodiments described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The exemplary embodiments are described below with reference to the following drawings:

[0040] Figure 1 A schematic diagram of a new three - position disconnect switch shown in three different switch positions is presented, and;

[0041] Figure 2 A detailed representation of the intermediate or power output contacts of the new three - position disconnect switch is shown, a three - position disconnect switch. Detailed Description

[0042] Figures 1 to 2 Relates to a new three - position disconnect switch in several different exemplary embodiments, where other specific exemplary embodiments are described below.

[0043] In an example, the three - position disconnect switch includes a power input contact 1, a piston 2, a power output contact 4, a plurality of flexible locking elements 5, a ground contact 6, and a threaded rod 7. The length of the piston is such that in the first switch position, the outer surface of the wall of the piston forms an electrical contact between the power input contact and the power output contact. The length of the piston is such that in the second switch position, the outer surface of the wall of the piston is not in electrical contact with the ground contact or the power input contact. In the second switch position, the outer surface of the wall of the piston is in electrical contact with the power output contact. The length of the piston is such that in the third switch position, the outer surface of the wall of the piston forms an electrical contact between the ground contact and the power output contact. The piston includes an internal threaded section configured to engage with the threaded rod, and rotation of the threaded rod is configured to engage with the internal threaded section to move the piston along the axis of the switch between different switch positions. The piston includes a groove extending in a direction parallel to the axis. Each of the flexible locking elements is configured such that when the piston is moved along the axis of the switch between different switch positions, a portion of each of the flexible locking elements moves into and out of the groove as the piston moves along the axis in both directions. When the piston moves along the axis, the switch is configured such that a portion of at least one flexible locking element is always located in the groove. When a portion of at least one flexible locking element is located in the groove, the piston is constrained from rotating about the axis.

[0044] According to the example, each of the plurality of flexible locking elements is non - conductive.

[0045] According to the example, the power output contact includes a first part and a second part. The first part is electrically connected to the second part. In the first switch position, the outer surface of the wall of the piston is in direct electrical contact with the first part of the power output contact and is in direct electrical contact with the power input contact. In the second switch position, the outer surface of the wall of the piston is in direct electrical contact with the first part of the power output contact and is in direct electrical contact with the second part of the power output contact. In the third switch position, the outer surface of the wall of the piston is in direct electrical contact with the second part of the power output contact and is in direct electrical contact with the ground contact.

[0046] According to the example, the first flexible locking element (among the plurality of flexible locking elements) is connected to the power output contact and is located on the side of the power output contact facing the power input contact; and the second flexible locking element (of the plurality of flexible locking elements) is connected to the power output contact and is located on the side of the power output contact facing the ground contact.

[0047] According to the example, in the first switch position, a portion of the first flexible locking element is located in the groove. In the second switch position, a portion of the first flexible locking element is located in the groove, and a portion of the second flexible locking element is located in the groove. In the third switch position, a portion of the second flexible locking element is located in the groove.

[0048] According to the example, in the first switch position, a portion of the second flexible locking element is not located in the groove. In the third switch position, a portion of the first flexible locking element is not located in the groove.

[0049] According to the example, the first flexible locking element is connected to the first part of the power output contact and is located on the side of the first part of the power output contact facing the power input contact; and the second flexible locking element is connected to the second part of the power output contact and is located on the side of the second part of the power output contact facing the ground contact. In the first switch position, a portion of the first flexible locking element is located in the groove.

[0050] According to the example, in the first switch position, a portion of the second flexible locking element is not located in the groove.

[0051] According to the example, the third flexible locking element (among the plurality of locking elements) is connected to the first part of the power output contact and is located on the side of the first part of the power output contact facing the ground contact; and the fourth flexible locking element (among the plurality of flexible locking elements) is connected to the second part of the power output contact and is located on the side of the second part of the power output contact facing the power input contact. In the second switch position, a portion of the third flexible locking element is located in the groove; and in the second switch position, a portion of the fourth flexible locking element is located in the groove.

[0052] According to the example, the first flexible locking element is connected to the second part of the power output contact and is located on the side of the second part of the power output contact facing the power input contact; and the second flexible locking element is connected to the part of the first power output contact and is located on the side of the first part of the power output contact facing the ground contact. In the second switch position, a part of the first flexible locking element is located in the groove, and a part of the second flexible locking element is located in the groove.

[0053] According to the example, the third flexible locking element (among the plurality of flexible locking elements) is connected to the power input contact and is located on the side of the power input contact facing the ground contact; and the fourth flexible locking element (among the plurality of flexible locking elements) is connected to the ground contact and is located on the side of the ground contact facing the power input contact. In the first switch position, a part of the third flexible locking element is located in the groove; and in the third switch position, a part of the fourth flexible locking element is located in the groove.

[0054] According to the example, in the first switch position, a part of the second flexible locking element is not located in the groove; and in the third switch position, a part of the first flexible locking element is not located in the groove.

[0055] According to the example, the groove does not extend to the first distal end of the piston.

[0056] According to the example, the groove does not extend to the second distal end of the piston opposite to the first distal end.

[0057] In the example, the end of the groove at the first distal end and the end of the groove at the second distal end are inclined.

[0058] According to the example, the plurality of flexible locking elements are configured to flex.

[0059] In the example, the plurality of flexible locking elements are configured to flex such that a part of each flexible locking element moves substantially in the radial direction with respect to the axis of the switch.

[0060] In the example, the flexible locking element is configured to flex in a bow-shaped manner.

[0061] From the above, it can be clearly seen that one or more three-position disconnect switches as described above can be used in low-voltage, medium-voltage or high-voltage switchgear or control equipment, where for example, three such disconnect switches can be utilized, one for each phase of a three-phase system.

[0062] Continuing with the new three-position disconnect switch, in its embodiment, the following relates to detailed specific embodiments.

[0063] Figure 1Shows a specific detailed embodiment of a new three - position disconnect switch. The disconnect switch in the first switch position is shown at the top of the figure. The piston 2 is in the left - hand position and connects the busbar contact 1 (also known as the power input contact) to the left - hand part of the intermediate contact 4, which is also the first part of the power output contact. The power output contact 4 actually has two parts, and the flexible locking elements 5 extend on either side of each part of the power output contact 4. The piston 2 has a groove 3, and one of the flexible locking elements 5 is located in the groove and stops the piston from rotating about the axis of the switch. The center of the piston is threaded, and the threaded rod 7 extends along the axis. Rotation of the thread causes the piston to move along the axis because the piston cannot rotate. The threaded rod 7 is not shown in Figure 1 but is shown in Figure 2 .

[0064] Continuing Figure 2 , the center picture shows the piston in the second switch position, where the piston is contacting both parts of the intermediate or power output contact 4. Here, two flexible locking elements are located in the groove, thus preventing the piston from rotating axially. Figure 2 The bottom picture of

[0065] shows the piston in the third switch position, which connects the right - hand part or the second part of the power output contact 4 to the ground contact 6. Here, one flexible locking element is located in the groove, thus preventing the piston from rotating axially. Figure 2 As the thread rotates and drives the piston through the different switch positions, at least one flexible locking element is always located in the groove. It should be noted that Figure 2 shows a detailed view of the intermediate or power output contact, where the piston connects the two parts together and parts of the flexible locking elements are located in the groove of the piston, thus preventing the piston from rotating axially. As shown, the groove has tapered ends, and in fact, the ends of the piston are also tapered. This means that when the tapered end of the groove or the tapered end of the piston encounters the flexible locking element, it will gradually push it out of the groove to the top of the piston; or when the piston first encounters the flexible locking element, it will push the flexible locking element onto the top of the piston; and then when it encounters the groove, the flexible locking element flexes down into the groove.

[0066] Therefore, returning to Figure 1 the first switch position of Figure 1As shown at the top of Figure 1 , the situation starts with a part of a flexible locking element being located in the groove. As the piston is driven from the first switch position to the right to the second switch position, it encounters a second flexible locking element and pushes it up onto the top of the piston; then as the piston moves further to the right, the second flexible locking element flexes downward into the groove; then as the piston continues to move to the right, the first flexible locking element encounters the left end of the groove and is pushed out of the groove and up onto the top of the piston; then as the piston moves further to the right, this first flexible locking element flexes downward. Additionally, when moving to the right, it encounters a third flexible locking element that extends from the left side of the second part of the power output contact and is again pushed outward and then flexes downward into the groove. Thus, in the second switch position, the second flexible locking element and the third flexible locking element are located in the groove, as

[0067] shown in the middle of

[0068] . Then, as the piston continues to be driven to the right towards the third switch position, the second flexible locking element exits the groove and a fourth flexible locking element enters the groove, where in the intermediate stage, there are two flexible locking elements in the groove; finally when the piston is driven all the way to the third switch position, only the fourth flexible locking element remains in the groove. However, when the piston is driven by the rotation of the thread, at least one flexible locking element remains in the groove at all times, thus preventing the piston from rotating axially.

[0069] Therefore, by making the locking element flexible, it is allowed that the groove portion is located somewhere in the intermediate section on the piston, and the groove does not need to pass all the way through the top of the piston and open at the ends. A plastic cover / bearing including flexible locking elements can be utilized. Several components can be located on each part of the intermediate contact. This arrangement provides rotational locking along the entire stroke of the isolating piston. The non-conductivity of the flexible locking element means that it does not shorten the air gap between the intermediate contact and the busbar or the ground contact. Another advantage of this setup is that the groove can be made outside the contact area of the isolating switch piston, so the contact performance is not impaired. Additionally, since the groove is only located in the intermediate part, there are no sharp edges on the ends of the piston, which helps with dielectric performance and reduces the necessary air gap length. Finally, using four flexible elements allows for the shortest piston while locking the piston to prevent rotation along the entire stroke (the piston only needs to have the length from contact to contact).

[0070] Accordingly, the new technology provides a set of flexible locking elements that can slide / flex into a groove on the disconnector piston, which is located somewhere in the middle section of the piston. The locking elements are located on the intermediate contact to ensure that the isolating piston is locked along the entire stroke of the piston to prevent rotation. This arrangement provides the most space-saving solution.

[0071] However, a slightly different flexible locking element arrangement can be utilized. Here, instead of the 2 external flexible locking elements as described above being connected to the first and second parts of the intermediate or power output contact 4, these can be transferred to the power input contact 1 and the ground contact 6, and face inwards. The operation of the disconnector is very similar to that described above with respect to Figures 1 to 2 where at least one flexible locking element is always located within the groove as the piston is driven from one position to the next, thereby preventing axial rotation of the piston. In this arrangement, the flexible locking elements removed from the intermediate contact and now energized in the ungrounded contacts need to be longer than before, which results in a degradation of the dielectric properties. However, under certain circumstances, if there are constraints regarding the use of the previously described embodiments, this embodiment can be utilized.

Claims

1. A three-position disconnect switch, comprising: - a power input contact (1); - a piston (2); - a power output contact (4); - a plurality of flexible locking elements (5); - a grounding contact (6); and - a threaded rod (7); wherein the length of the piston is such that in a first switch position, an outer surface of a wall of the piston forms an electrical contact between the power input contact and the power output contact; wherein the length of the piston is such that in a second switch position, the outer surface of the wall of the piston is not in electrical contact with the grounding contact or the power input contact, and wherein in the second switch position, the outer surface of the wall of the piston forms an electrical contact with the power output contact; wherein the length of the piston is such that in a third switch position, the outer surface of the wall of the piston forms an electrical contact between the grounding contact and the power output contact; wherein the piston includes an internally threaded section configured to engage with the threaded rod, and wherein rotation of the threaded rod is configured to engage with the internally threaded section to move the piston along an axis of the switch between different switch positions; wherein the piston includes a groove extending in a direction parallel to the axis; wherein each of the flexible locking elements is configured such that as the piston moves along the axis of the switch between the different switch positions, a portion of each of the flexible locking elements moves into and out of the groove as the piston moves along the axis in two directions; wherein as the piston moves along the axis, the switch is configured such that a portion of at least one flexible locking element is always located in the groove; and wherein when a portion of at least one flexible locking element is located in the groove, the piston is constrained from rotating about the axis.

2. The switch according to claim 1, wherein each of the plurality of flexible locking elements is non-conductive.

3. The switch according to any one of claims 1 to 2, wherein the power output contact includes a first portion and a second portion, wherein the first portion is electrically connected to the second portion, wherein in the first switch position, the outer surface of the wall of the piston is in direct electrical contact with the first portion of the power output contact and in direct electrical contact with the power input contact, wherein in the second switch position, the outer surface of the wall of the piston is in direct electrical contact with the first portion of the power output contact and in direct electrical contact with the second portion of the power output contact, and wherein in the third switch position, the outer surface of the wall of the piston is in direct electrical contact with the second portion of the power output contact and in direct electrical contact with the grounding contact.

4. The switch according to any one of claims 1 to 2, wherein a first flexible locking element among the plurality of flexible locking elements is connected to the power output contact and is located on a side of the power output contact facing the power input contact; and a second flexible locking element among the plurality of flexible locking elements is connected to the power output contact and is located on a side of the power output contact facing the ground contact.

5. The switch according to claim 3, wherein a first flexible locking element among the plurality of flexible locking elements is connected to the power output contact and is located on a side of the power output contact facing the power input contact; and a second flexible locking element among the plurality of flexible locking elements is connected to the power output contact and is located on a side of the power output contact facing the ground contact.

6. The switch according to claim 4, wherein in the first switch position, the portion of the first flexible locking element is located in the groove, wherein in the second switch position, the portion of the first flexible locking element is located in the groove, and the portion of the second flexible locking element is located in the groove, and wherein in the third switch position, the portion of the second flexible locking element is located in the groove.

7. The switch according to claim 6, wherein in the first switch position, the portion of the second flexible locking element is not located in the groove, and wherein in the third switch position, the portion of the first flexible locking element is not located in the groove.

8. The switch according to claim 5, wherein the first flexible locking element is connected to the first portion of the power output contact and is located on a side of the first portion of the power output contact facing the power input contact, and the second flexible locking element is connected to the second portion of the power output contact and is located on a side of the second portion of the power output contact facing the ground contact, and wherein in the first switch position, the portion of the first flexible locking element is located in the groove.

9. The switch according to claim 8, wherein in the first switch position, the portion of the second flexible locking element is not located in the groove.

10. The switch according to any one of claims 8 to 9, wherein a third flexible locking element of the plurality of flexible locking elements is connected to the first portion of the power output contact, and is located on a side of the first portion of the power output contact facing the ground contact, and a fourth flexible locking element of the plurality of flexible locking elements is connected to the second portion of the power output contact, and is located on a side of the second portion of the power output contact facing the power input contact, and wherein in the second switch position, the portion of the third flexible locking element is located in the groove, and in the second switch position, the portion of the fourth flexible locking element is located in the groove.

11. The switch according to claim 5, wherein the first flexible locking element is connected to the second portion of the power output contact, and is located on a side of the second portion of the power output contact facing the power input contact, and the second flexible locking element is connected to the first portion of the power output contact, and is located on a side of the first portion of the power output contact facing the ground contact, and wherein in the second switch position, the portion of the first flexible locking element is located in the groove, and the portion of the second flexible locking element is located in the groove.

12. The switch according to claim 11, wherein a third flexible locking element of the plurality of flexible locking elements is connected to the power input contact, and is located on a side of the power input contact facing the ground contact, and a fourth flexible locking element of the plurality of flexible locking elements is connected to the ground contact, and is located on a side of the ground contact facing the power input contact, and wherein in the first switch position, the portion of the third flexible locking element is located in the groove, and in the third switch position, the portion of the fourth flexible locking element is located in the groove.

13. The switch according to claim 12, wherein in the first switch position, the portion of the second flexible locking element is not located in the groove, and wherein in the third switch position, the portion of the first flexible locking element is not located in the groove.

14. The switch according to any one of claims 1 to 2, wherein the groove does not extend to the first distal end of the piston.

15. The switch according to claim 14, wherein the groove does not extend to the second distal end of the piston opposite the first distal end.

16. The switch according to any one of claims 1 to 2, wherein the plurality of flexible locking elements are configured to flex.

17. A low-voltage, medium-voltage or high-voltage switchgear or control device, comprising one or more three-position disconnectors according to any one of claims 1 to 16.

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