TRANSFORMER COMPRISING A LOAD BREAK ROTARY SWITCH

Abstract

A transformer comprises a transformer housing, a stationary contact, a load break rotary switch and a magnetically sensitive indicator component. The load break rotary switch comprises a shaft, comprising a shaft portion which is disposed in an inner housing area and a shaft contact attached to the shaft portion. The load break rotary switch further comprises a lever connected to the shaft portion with respect to a rotary axis in a rotationally fixed manner, wherein the lever comprises a lever portion having a radial distance from the rotary axis. The lever portion comprises a lever magnet. A magnetically sensitive indicator component is switched from its first state into its second state by the lever magnet when the shaft is rotated from the first position to the second position or vice versa. Thus, an operator can ensure that the shaft contact is disconnected from the stationary contact before performing a maintenance work.

Claims

1. A transformer, comprising: a transformer housing, comprising a transformer housing wall separating an inner housing area from an outer housing area; a stationary contact disposed stationary relative to the housing; a load break rotary switch comprising a shaft, comprising a shaft portion which is disposed in the inner housing area and a shaft contact attached to the shaft portion, wherein the shaft is supported with respect to the transformer housing wall rotatably about a rotary axis (R) between a first position in which the shaft contact is electrically connected to the stationary contact and a second position in which the shaft contact is electrically not connected to the stationary contact; and a lever connected to the shaft portion with respect to the rotary axis (R) in a rotationally fixed manner, wherein the lever is an integral part of the shaft portion or a separate part, attached to the shaft portion, wherein the lever comprises a lever portion having a radial distance (d) from the rotary axis (R), wherein the lever portion comprises a lever magnet; and a magnetically sensitive indicator component attached to the transformer housing wall, wherein the magnetically sensitive indicator component is placeable selectively into a first state in which the magnetically sensitive indicator component is indicative of the first state and into a second state in which the magnetically sensitive indicator component is indicative of the second state, wherein the magnetically sensitive indicator component is switched from its first state into its second state by the lever magnet when the shaft is rotated from the first position to the second position or vice versa.

2. The transformer of claim 1, wherein the magnetically sensitive indicator component is disposed within the outer housing area.

3. The transformer of claim 1, further comprising a handle disposed in the outer housing area, wherein the handle is configured to initiate, upon a manipulation of the handle, a rotation of the shaft from the first position into the second position or vice versa.

4. The transformer of claim 1, wherein the magnetically sensitive indicator component comprises a switch.

5. The transformer of claim 1, wherein the magnetic sensitive indicator component comprises a visually and/or audible perceivable that indicates whether the magnetic sensitive indicator component is in its first state or in its second state.

6. The transformer of claim 1, further comprising at least one further stationary contact fixedly disposed relative to the housing, wherein at least one further shaft contact is fixedly attached to the shaft portion, wherein, when the shaft is in the first position, the at least one further shaft contact is electrically connected to the at least one further stationary contact and, when the shaft is in the second position, the at least one further shaft contact is electrically disconnected from the at least one further stationary contact.

7. The transformer of claim 1, wherein the load break rotary switch is a three-phase switch.

8. The transformer of claim 1, wherein the transformer is a submersible transformer.

9. The transformer of claim 8, wherein the transformer comprises a tank and the housing wall is a wall of the tank.

10. The transformer of claim 1, wherein the transformer is a pad mounted transformer.

11. The transformer of claim 1, wherein the transformer is a distribution transformer.

12. The transformer of claim 1, wherein the shaft contact is a blade contact.

13. The transformer of claim 1, further comprising a core and a winding, wherein the stationary contact is electrically connected to the winding.

14. The transformer of claim 4, wherein the switch comprises a reed or a sensor.

15. The transformer of claim 5, wherein the visually perceivable element comprises a light emitting diode.

16. The transformer of claim 8, wherein the submersible transformer comprises an oil-immersed transformer.

17. The transformer of claim 13, wherein the winding comprises high-voltage winding.

18. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The subject-matter of the disclosure will be explained in more detail with reference to exemplary embodiments which are illustrated in the attached drawings, in which:

[0036] FIG. 1a is a schematic cross-sectional view of a load break rotary switch mounted within a transformer housing wall and stationary contacts, wherein contacts of the load break rotary switch are disconnected from the stationary contacts.

[0037] FIG. 1b is a corresponding view, wherein the contacts of the load break rotary switch are connected to the stationary contacts.

[0038] FIG. 2a is a schematic plan view showing the load break rotary switch and the stationary contacts illustrated in FIG. 1a.

[0039] FIG. 2b is a corresponding plan view showing the load break rotary switch and the stationary contacts illustrated in FIG. 1b.

DETAILED DESCRIPTION

[0040] Example embodiments of the disclosure will be described with reference to the drawings in which identical or similar reference signs designate identical or similar elements.

[0041] The features of embodiments may be combined with each other, unless specifically noted otherwise.

[0042] FIG. 1a is a schematic cross-sectional view of a load break rotary switch 6 of a transformer. The term “load break rotary switch” as used herein indicates a rotary switch designed and arranged to make and to break a load of a transformer. Accordingly, the load break rotary switch might be as well indicated as “load break and load make rotary switch”.

[0043] The transformer comprises a transformer housing having a transformer housing wall 2. Only a part of the transformer housing wall 2 is illustrated in FIG. 1a. The transformer housing wall 2 surrounds elements of the transformer such as, e.g., a core and a winding (not illustrated in the figures) as well-known as such in the art.

[0044] The transformer may be designed to selectively connect and disconnect a network to or from a distribution line. The transformer may be a distribution transformer. The transformer may be a pad mounted transformer.

[0045] For example, the transformer may be an oil-immersed transformer having a tank filled with oil, wherein the core and the winding are at least partly submerged within the oil. The tank may be arranged within the housing. Alternatively, the housing wall 2 may be a wall of the tank.

[0046] The transformer housing wall 2 separates an inner housing area I from an outer housing area II. The inner housing area I may be at least partly filled with the oil. The outer housing area II may be an area exterior to the housing, wherein the outer housing area II is accessible to an operator of the transformer.

[0047] The transformer comprises a stationary contact 4 disposed stationary relative to the housing, i.e., relative to the transformer housing wall 2. The stationary contact 4 may be electrically connected e.g., to the network. The stationary contact 4 may be electrically connected to the winding of the transformer.

[0048] The load break rotary switch 6 comprises a shaft 8. The shaft 8 comprises a shaft portion 10 which is disposed in the inner housing area I and a shaft contact 12 attached to the shaft portion 10, particularly fixed to the shaft portion 10. The shaft contact 12 may be electrically connected e.g., to the distribution line. The shaft contact 12 may be a blade contact.

[0049] The shaft 8 is supported with respect to the transformer housing wall 2 rotatably about a rotary axis R between a first position in which the shaft contact 12 is electrically connected to the stationary contact 4 and a second position in which the shaft contact 12 is not electrically connected to the stationary contact 4. FIG. 1a shows a state in which the shaft contact 12 is not electrically connected to the stationary contact 4, i.e., in which the shaft is in its second position, whereas FIG. 1b shows a state in which the shaft contact 12 is electrically connected to the stationary contact 4, i.e., in which the shaft is in its first position.

[0050] The load break rotary switch 6 further comprises a lever 14. The lever 14 is connected to the shaft portion 10 with respect to the rotary axis R in a rotationally fixed manner. The lever 14 may be an integral part of the shaft portion 10. Alternatively, the lever 14 may be a separate part, attached to the shaft portion 10 for example by a plug-in connection.

[0051] The lever 14 comprises a lever portion 16 having a radial distance d from the rotary axis R, wherein the lever portion 16 comprises a lever magnet 18. For example, the lever 14 may be L-shaped as exemplarily illustrated in FIG. 1a with one of the arm or—as illustrated in FIG. 1a—the stem of the “L” comprising the lever portion 18. The lever magnet 18 is arranged such that it has only a small distance from the transformer housing wall 2, for example a distance that is smaller than the radial distance d, such as smaller than 0.5 d. The design is further such that the distance of the lever magnet 18 from the transformer housing wall 2 does not change as the shaft 8 is rotated between its first and second position.

[0052] The transformer further comprises a magnetically sensitive indicator component 20 attached to the transformer housing wall 2. For example, the magnetically sensitive component may be disposed within the outer housing area II. The magnetically sensitive indicator component 20 is placeable selectively into a first state in which the magnetically sensitive indicator component 20 is indicative of the first state and into a second state in which the magnetically sensitive indicator component 20 is indicative of the second state.

[0053] When the shaft 8 is rotated from the first position to the second position, the magnetically sensitive indicator component 20 is switched from its first state into its second state—or vice versa—by the lever magnet 18.

[0054] Thus, it is possible for the operator of the transformer to determine whether the shaft 8 is in its first or second position and correspondingly to determine whether or not the shaft contact 12 is electrically connected to the stationary contact 4. Therefore, the operator can make sure that—for example—the transformer is disconnected from the network before doing a maintenance work at the line.

[0055] The transformer may further comprise a handle 22 disposed in the outer housing area II, wherein the handle 22 is connectable or connected to the shaft 8. For example, the handle 22 may be configured to initiate, upon a manipulation of the handle 22, a rotation of the shaft 8 from the first position into the second position or vice versa.

[0056] FIGS. 2a and 2b show schematically plan views of the arrangements illustrated in FIGS. 1a and 1b, respectively.

[0057] The magnetically sensitive indicator component 20 may comprise a switch, particularly a reed or a sensor. The magnetically sensitive component 20, particularly in the form of a reed or a sensor, can be connected with a control panel of a sub-station. Thus, a system comprising at least two transformers according to the present application makes it possible for an operator to monitor, instantly, load break rotary switches installed on the at least two transformers.

[0058] In some embodiments, the magnetically sensitive indicator component 20 comprises a visually and/or audible perceivable element 24, for example a LED, wherein the magnetically sensitive indicator component 20 is designed such that the visually and/or audible perceivable element 24 indicates whether the magnetic sensitive indicator component 20 is in its first state or in its second state. In this manner, a particularly easy and safe determination of the position of the shaft 8 is possible for the operator.

[0059] The transformer may further comprise at least one further stationary contact 4′ fixedly disposed relative to the housing, wherein at least one further shaft contact 12′ is fixedly attached to the shaft portion 10, wherein, when the shaft 8 is in the first position, the at least one further shaft contact 12′ is electrically connected to the at least one further stationary contact 4′ and, when the shaft 8 is in the second position, the at least one further shaft contact 12′ is not electrically connected to the at least one further stationary contact 4′. For example, as illustrated in FIG. 1a, the load break rotary switch may be a three-phase switch.

[0060] While the disclosure has been described in detail in the drawings and forgoing description, such description is to be considered illustrative or exemplary and not restrictive. Variations to the disclosed embodiments can be understood and effected by those skilled in the art and practicing the claimed subject matter, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. The mere fact that certain elements or steps are recited in distinct claims does not indicate that a combination of these elements or steps cannot be used to advantage, specifically, in addition to the actual claim dependency, any further meaningful claim combination shall be considered disclosed.