Actuating apparatus for a vacuum interrupter and disconnecting arrangement

Abstract

An actuating device for a vacuum switching tube has a connecting element which can be connected to an electric contact of the vacuum switching tube, an electromagnetic actuating device for displacing the connecting element between a first and a second position, and a retaining yoke, relative to which the connecting element can be displaced and has a first magnetic element. The first magnetic element generates a first and a second magnetic circuit in the retaining yoke. The actuating device further has a ferromagnetic retaining anchor, which is arranged on the connecting element. The retaining anchor is located in the first position of the connecting element in the first magnetic circuit and in the second position of the connecting element in the second magnetic circuit. The connecting element is held in the first and in the second position by a respective magnetic force between the retaining yoke and the retaining anchor.

Claims

1. A disconnecting configuration for disconnecting an electrical circuit, the disconnecting configuration comprising: at least one vacuum interrupter having two electrical contacts; a controller; and at least one actuating apparatus, said actuating apparatus containing: a connecting element; an electromagnetic actuating device for moving said connecting element between a first position and a second position; a retaining yoke, relative to said retaining yoke said connecting element is moveable, said retaining yoke having a first magnet element, said first magnet element bringing about a first magnetic circuit and a second magnetic circuit in said retaining yoke; a ferromagnetic retaining armature disposed on said connecting element, said ferromagnetic retaining armature disposed in said first magnetic circuit in the first position of said connecting element and in said second magnetic circuit in the second position of said connecting element; said connecting element is held stably in the first position and in the second position by a respective magnetic force between said retaining yoke and said retaining armature; and said connecting element of said at least one actuating apparatus is connected to one of said contacts of said at least one vacuum interrupter in such a way that said contacts are open in the first position of said connecting element and are closed in the second position of said connecting element; said controller for controlling an electric current flowing through said coil element of said at least one actuating apparatus, said controller configured for reducing the electric current flowing through said coil element if said connecting element draws close to the first or second position.

2. The disconnecting configuration according to claim 1, wherein said controller has a bridge circuit with semiconductor switches.

3. The disconnecting configuration according to claim 1, further comprising a damping element for reducing a movement velocity of said connecting element.

4. The disconnecting configuration according to claim 1, further comprising an emergency switching element for closing said contacts of said vacuum interrupter.

5. The disconnecting configuration according to claim 1, wherein: said at least one actuating apparatus is one of two actuating apparatuses; said at least one vacuum interrupter is one of two vacuum interrupters; and said controller is configured to control the electric current flowing through said coil element of a first one of said two actuating apparatuses and the electric current flowing through said coil element of a second one of said two actuating apparatuses in a manner temporally offset with respect to one another.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

(1) The invention will now be explained in more detail with reference to the attached drawings, in which:

(2) FIG. 1 shows a disconnecting arrangement in a schematic illustration;

(3) FIG. 2 shows a control device of the disconnecting arrangement;

(4) FIG. 3 shows the time profile of a position of a contact of a vacuum interrupter of the disconnecting arrangement;

(5) FIG. 4 shows a time profile of a velocity of the contact;

(6) FIG. 5 shows a time profile of the current intensity through a coil element of the disconnecting arrangement;

(7) FIG. 6 shows a time profile of the electric voltage at a capacitor of the control device;

(8) FIG. 7 shows a disconnecting arrangement in a second embodiment; and

(9) FIG. 8 shows a disconnecting arrangement in a third embodiment.

DESCRIPTION OF THE INVENTION

(10) The exemplary embodiments described in more detail below represent preferred embodiments of the present invention.

(11) FIG. 1 shows a disconnecting arrangement 10 in a schematic illustration. The disconnecting arrangement 10 comprises a vacuum interrupter 12. The vacuum interrupter 12 serves to disconnect an electrical connecting line, in particular a high-voltage electrical line. The vacuum interrupter 12 comprises a stationary contact 14 and a moveable contact 16. Furthermore, the disconnecting arrangement 10 comprises an actuating apparatus 18. The actuating apparatus 18 comprises a connecting element 20, which is mechanically connected to the moveable contact 16 and the vacuum interrupter 12. Owing to a movement of the connecting element 20, the moveable contact 16 can be moved, i.e. the vacuum interrupter 12 can be opened or closed.

(12) Furthermore, the actuating apparatus 18 comprises two retaining yokes 22. Each retaining yoke 22 is arranged fixedly on the connecting element 20. A first magnet element 24 is arranged on the retaining yoke 22. The first magnet element 24 can be formed by a permanent magnet. The first magnet element 24 can also be integrated in the respective retaining yoke 22. In addition, the actuating apparatus 18 comprises a retaining armature 26, which is mechanically connected to the connecting element 20. Along the retaining armature 26, the first magnet element 24 and the retaining yoke, a first closed magnetic circuit is formed in a first position (illustrated here) of the connecting element 20. In the present first position, the electrical contacts 14, 16 of the vacuum interrupter 12 are open.

(13) In order to close the contacts 14, 16 of the vacuum interrupter 12, the connecting element 20 needs to be moved from the first position into a second position. For this purpose, the electromagnetic actuating device 28 is used. The electromagnetic actuating device 28 comprises a second magnet element 30. The second magnet element 30 comprises a plurality of permanent magnets 32. In the present case, the second magnet element 30 comprises two arrangements of permanent magnets 32 which are physically separated from one another. The magnetization direction of the respective permanent magnets is identified by the arrows 34. Furthermore, the electromechanical actuating device 28 comprises a coil element 36. The coil element 36 is mechanically connected to the connecting element 20. The permanent magnets 32 are in this case arranged in such a way that they at least regionally surround the coil element 36. The coil element 36 has corresponding windings 38, which extend perpendicular to the magnetization direction of the permanent magnets 32 in the region in which they are surrounded by the permanent magnet 32.

(14) Furthermore, the disconnecting arrangement 10 comprises a control device 40. The electric current in the coil element 36 can be controlled by the control device 40. If an electric current of a first polarity is applied to the coil element 36, the connecting element 20 is moved from the first position into the second position. If a current intensity of a second polarity is applied to the coil element 36, the connecting element is moved back to the first position from the second position.

(15) FIG. 2 shows a circuit arrangement of the control device 40. The control device 40 comprises a bridge circuit 42 in the form of an H bridge or full bridge. The bridge circuit 42 comprises the semiconductor switching elements, which are in the form of transistors or IGBTs, for example, and which each comprise an inversely switched diode 46. Furthermore, the bridge circuit 42 comprises a capacitor 48, which is fed via a precharging device 50. The electric current through the coil element 36 can be adapted in a simple manner by the bridge circuit 42.

(16) FIG. 3 shows the profile 52 of the position p of the moveable contact element 16 as a function of time t. During operation of the actuating apparatus 18, the connecting element 20 is intended to be actuated in such a way that the moveable contact 16 is initially accelerated into the second position starting from the first position. Prior to the second position being reached, the velocity v of the second contact element needs to be reduced. This is represented in the profile 54 in FIG. 4. It is thus possible to prevent the connecting element 20 or the retaining armature 26 from hitting the retaining yoke 22 in the second position. For this purpose, the electric current flowing through the coil element 36 is initially increased. Then, the polarity of the electric current is reversed, as a result of which a braking force which is directed opposite the movement velocity v of the moveable contact 16 is generated. The time profile of the electric current intensity I through the coil element is shown by the profile 56 in FIG. 5. FIG. 6 shows, in the profile 58, the electric voltage U at the capacitor 48.

(17) FIG. 7 shows the disconnecting arrangement 10 in a further embodiment. The disconnecting arrangement 10 comprises an emergency switching element 60. The emergency switching element 60 can comprise a pyro element or a tensioned spring. In the event of an emergency, i.e. in the case of a failure of the electromagnetic actuating device 28, the connecting element 20 can be moved from the first position into the second position with the aid of the emergency switching device 60. Thus, the electrical contacts 14, 16 can be closed.

(18) Finally, FIG. 8 shows a further embodiment of a disconnecting arrangement 10. The disconnecting arrangement 10 illustrated here comprises two vacuum interrupters 12, 12, which are each connected to an actuating apparatus 18 and 18, as explained previously in connection with FIG. 1. In the present case, only one control device 40 is used, with which both the coil element 36 and the coil element 36 of the second actuating apparatus 18 can be actuated. In this case, by virtue of the actuation of the coil elements 36, 36 of the control apparatus 40, the electromagnetic actuating devices 28, 28 of the first actuating apparatus 18 and the second actuating apparatus 18 can be switched in opposition. Owing to the impulse neutrality, good mechanical stability can be achieved.