EP2885803B1 - Actuating device for a vacuum switching tube and separation arrangement - Google Patents

Description

The present invention relates to an adjusting device for a vacuum interrupter. Moreover, the present invention relates to a disconnecting device for disconnecting an electrical circuit.

In mechanical interruption units of medium and high voltage switching devices spring drives are usually used as drives for the mechanical opening and closing of the contact system today. This results in a necessary minimum mechanism that limits the achievable switching times, for example, to a range between 10 and 50 ms. Such switching times are too low in electrical isolation arrangements for high-voltage direct current transmission. There is therefore a desire to provide corresponding adjusting devices, with which the contacts can be separated faster. In particular, switching times in the single-digit millisecond range are desired here.

In order to realize such switching times, for example micro gas generators are used. Another possibility is to provide appropriate explosion drives. Furthermore, electromagnetic drives are proposed for the medium voltage range. In "Fiber-Controlled Vacuum Interrupter Module Used for Fault Current Interruption" of D. Xiongying et al., Published at the XXIV.th International Symposium on Discharge and Electrical Insulation in Vacuum, Braunschweig, 2010 , An adjusting device for a vacuum interrupter is described, which comprises an electromagnetic actuator, which is constructed according to the Tauchspulenprinzip.

Further, in the article "A DC Hybrid Circuit Breaker With Ultra-Fast Contact Opening and Integrated Gate Commutated Thyristors (IGCTs) "from J.-M. Meyer et al., Published in IEEE Transactions on Power Delivery, Vol. 2.2006 , an adjusting device for a vacuum interrupter is described which comprises an electromagnetic actuator. The holding force during closing is achieved by the magnetization of permanent magnets. To open a so-called Thomson actuator is used.

Furthermore, the describes JP 2002 033034 A a switching device having a repulsion plate which is disposed between an opening coil and a closing coil. By supplying power to each of the coils, contacts can be driven to open or close. In the opened state, a switching device is held with an opening holding mechanism which has a fixed core composed of U-shaped steel plates and a permanent magnet, and a magnetic material.

It is an object of the present invention to provide a faster and more efficient positioning device for opening and closing the contacts of a vacuum interrupter.

This object is achieved by an adjusting device having the features of patent claim 1 and by a separating arrangement having the features of patent claim 4. Advantageous developments of the present invention are specified in the subclaims.

The vacuum interrupter positioning device according to the invention comprises a connecting element which is connectable to an electrical contact of the vacuum interrupter, an electromagnetic actuating device for moving the connecting element between a first and a second position, a holding yoke, to which the connecting element is relatively movable, and a first Magnetic element comprises, wherein the first magnetic element in the holding yoke causes a first and a second magnetic circuit, and a ferromagnetic retaining anchor disposed on the connecting element is, wherein the retaining anchor is 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, wherein the connecting element in the first and in the second position by a respective magnetic force between the holding yoke and the Holding armature is stably maintained and the electromagnetic actuator comprises a second magnetic element and a movable relative to the second magnetic element coil element which is connected to the connecting element.

The adjusting device serves to open and close the electrical contacts of a vacuum interrupter. The vacuum interrupter usually has a fixed and a movable electrical contact. The adjusting device comprises a connecting element, which can be connected to an electrical contact, in particular the movable electrical contact, the vacuum interrupter. Furthermore, the adjusting device comprises an electromagnetic actuating device, with which the connecting element between a first and a second position can be moved. Due to the interaction of the connecting element with the contact of the vacuum interrupter, the contacts of the vacuum interrupter can be opened in the first position of the connecting element and closed in the second position of the connecting element. On the connecting element, a holding anchor is arranged, which is formed of a ferromagnetic material. Furthermore, the adjusting device comprises a holding yoke, on which a first magnetic element is arranged or in which a first magnetic element is integrated.

The holding yoke is fixedly formed to the connecting element. The connecting element can therefore be moved relative to the holding yoke. The holding yoke and the holding anchor are now designed such that forms a magnetic circuit along the holding armature, the first magnetic element and the holding yoke both in the first position and in the second position. In other words, being a bistable Adjusting device provided with which the connecting element is kept stable due to the magnetic forces in the first and the second position. Thus, no electrical energy must be applied to hold the connecting element in the first or in the second position. Thus, the actuator can be operated very energy efficient.

In addition, the electromagnetic actuating device has a second magnetic element and a coil element movable relative to the second magnetic element, which is connected to the connecting element. In order to move the connecting element from the first position to the second position back and forth, an electromagnetic actuator is used. The electromagnetic setting device comprises a coil element, which is surrounded at least in regions by a second magnetic element. By the polarity of the electric current flowing through the coil element, a movement of the coil element relative to the second magnetic element can be effected. Thus, the connecting element can be moved in a simple manner. In this case, the second magnetic element may be formed waiving any ferromagnetic field guide. In particular, the second magnetic element may be formed only by permanent magnets. In this case, the second magnetic element can also be designed in the manner of a so-called Halbach array. In this case, the second magnetic element may comprise a plurality of permanent magnets whose magnetization direction is tilted relative to each other by 90 ° along the extension direction. Thus, the magnetic flux in the region of the second magnetic element, which surrounds the coil element at least partially, be amplified. Thus, a particularly efficient actuator for moving the connecting element can be provided.

In one embodiment, the first and second magnetic elements are integrally formed as a magnetic device. In other words, the second magnetic element of the electromagnetic actuator with the first magnetic element of the yoke are combined. This allows, for example, the use of a single permanent magnet in the actuator.

In a further embodiment, the retaining anchor and the coil element are integrally formed as a coil device. The retaining armature and the coil element can be combined in a common integrated coil device or a coil assembly. As a result, space can be saved and the weight of the actuator can be reduced.

Moreover, according to the invention, a separating arrangement is provided for disconnecting an electrical circuit. The disconnect assembly includes at least one vacuum interrupter having two electrical contacts and at least one of the previously described actuators, wherein the connector of the at least one actuator is connected to one of the contacts of the at least one vacuum interrupter such that the contacts are opened in the first position of the connector and are closed in the second position of the connecting element.

The separating arrangement can be used for disconnecting an electrical connection, in particular a high-voltage connection. The separation arrangement comprises at least one interrupter, which is commercially available, for example. Such a vacuum interrupter, for example, a rated voltage of 24 kW AC voltage, a rated operating current of 2 kA and a moving contact piece of 0.9 kg mass. The connecting element of the adjusting device is connected directly to the movable contact of the vacuum interrupter. Thus, a direct drive for the vacuum interrupter can be provided and thus it requires no additional components that would mean an additional moving mass.

In an embodiment, the separation arrangement comprises a control device for controlling one by the coil element the at least one actuator flowing electrical current, which is adapted to reduce the current flowing through the coil elements electrical current, if the connecting element approaches the first or second position. With the control device of the disconnecting device, the electric current flowing through the coil element can be adjusted. Thus, the movement of the connecting element, which is mechanically fixedly connected to the coil element, can be controlled in a simple manner. Due to the simple structure of the electromagnetic actuator particularly fast switching times can be achieved. Thus, the electromagnetic control device can be controlled such that over the movement of the connecting element, the electrical contacts of the vacuum interrupter in a shaping period, for example, 2 ms, a predetermined path, for example 4 mm, cover.

When the connecting element is to be moved from one of the positions to the other, the current intensity in the coil element can first be increased. This can speed up the connection element. As the connector approaches the first or second position, the current in the coil member may be reduced again. This reduces the speed of movement of the connecting element. It can also be provided that the polarity of the electric current flowing through the coil element is reversed. Thus, one of the movement speeds of the connecting element oppositely directed braking force is generated. Thus, it can be prevented that the retaining anchor abuts against the holding yoke in one of the positions and thus the retaining yoke or the retaining anchor are damaged or worn in continuous operation.

The control device preferably comprises a bridge circuit with semiconductor switches. The bridge circuit can be designed in particular as a full bridge or H-bridge. The semiconductor switches used may be MOSFET transistors or IGBTs become. Thus, an energy-efficient control of the coil element can be achieved.

In a further embodiment, the separating arrangement has a damping element for reducing a movement speed of the connecting element. In addition to the electrical control, mechanical or hydraulic dampers can be provided in the separating arrangement with which the speed of movement of the connecting element in a respective region of the first or second position of the connecting element is reduced. As a damping element, in particular a mechanical or hydraulic damper can be used, which converts the kinetic energy of the connecting element substantially in frictional heat. Thus, the movement of the connecting element can be easily braked.

In a further embodiment, the separating arrangement has a Notschaltelement for closing the contacts of the vacuum interrupter. In the event of a switching failure, i. if the vacuum interrupter can not be closed by a defect of the electromagnetic actuator, an emergency operation may be implemented. The emergency switching element used for this purpose can be formed either by a pyro element or by a tensioned spring, which is unlocked. Thus, the vacuum interrupter can be closed easily in an emergency again.

In one embodiment, the separating arrangement comprises two adjusting devices and two vacuum interrupters, wherein the control device is designed to control the electrical current flowing through the coil element of the first of the two actuating devices and through the coil element of the second of the two actuating devices with a time offset from one another. For example, the electromagnetic control devices of the two adjusting devices can be reversed. Due to the impulse neutrality to the outside, a good mechanical stability can be achieved.

Fig. 1

eine Trennanordnung in einer schematischen Darstellung;

Fig. 2

eine Steuereinrichtung der Trennanordnung;

Fig. 3

den zeitlichen Verlauf einer Position eines Kontakts einer Vakuumschaltröhre der Trennanordnung;

Fig. 4

einen zeitlichen Verlauf einer Geschwindigkeit des Kontakts;

Fig. 5

einen zeitlichen Verlauf der Stromstärke durch ein Spulenelement der Trennanordnung;

Fig. 6

einen zeitlichen Verlauf der elektrischen Spannung an einem Kondensator der Steuereinrichtung;

Fig. 7

eine Trennanordnung in einer zweiten Ausführungsform; und

Fig. 8

eine Trennanordnung in einer dritten Ausführungsform.

The invention will now be explained in more detail with reference to the accompanying drawings. Showing:

Fig. 1

a separation arrangement in a schematic representation;

Fig. 2

a control device of the separating arrangement;

Fig. 3

the time course of a position of a contact of a vacuum interrupter of the separation assembly;

Fig. 4

a time course of a speed of the contact;

Fig. 5

a time course of the current through a coil element of the separation arrangement;

Fig. 6

a time profile of the electrical voltage across a capacitor of the control device;

Fig. 7

a separating arrangement in a second embodiment; and

Fig. 8

a separating arrangement in a third embodiment.

The embodiments described in more detail below represent preferred embodiments of the present invention.

Fig. 1 shows a separating arrangement 10 in a schematic representation. The disconnect assembly 10 includes a vacuum interrupter 12. The vacuum interrupter 12 is for disconnecting an electrical connection line, particularly an electrical power line. The vacuum interrupter 12 comprises a fixed contact 14 and a movable contact 16. Furthermore, the separating arrangement 10 comprises an adjusting device 18. The adjusting device 18 comprises a connecting element 20, which is mechanically connected to the movable contact 16 and the vacuum interrupter 12. By a movement of the connecting element 20, the movable contact 16 can be moved, so the vacuum interrupter 12 are opened or closed.

Furthermore, the adjusting device 18 comprises two holding yokes 22. Each holding yoke 22 is arranged fixedly on the connecting element 20. On the holding yoke 22, a first magnetic element 24 is arranged. The first magnetic element 24 may be formed by a permanent magnet. The first magnetic element 24 may also be integrated into the respective holding yoke 22. In addition, the adjusting device 18 comprises a retaining anchor 26 which is mechanically connected to the connecting element 20. Along the retaining armature 26, the first magnetic element 24 and the holding yoke, a first closed magnetic circuit is formed in a first position of the connecting element 20 shown here. In the present first position, the electrical contacts 14, 16 of the vacuum interrupter 12 are opened.

In order to close the contacts 14, 16 of the vacuum interrupter 12, the connecting element 20 must be moved from the first position to a second position. For this purpose, the electromagnetic actuator 28 is used. The second magnetic element 30 comprises a plurality of permanent magnets 32. In the present case, the second magnetic element 30 comprises two mutually spatially separate arrangements of permanent magnets 32. The magnetization direction of the respective permanent magnets is indicated by the arrows 34. Furthermore, the electromechanical adjustment direction 30 comprises a coil element 36. The coil element 36 is mechanically connected to the connection element 20. The permanent magnets 32 are arranged so that they surround the coil element 36 at least partially. The coil element 36 has corresponding windings 38 which are in the area in which they are surrounded by the permanent magnet 32, extend perpendicular to the magnetization direction of the permanent magnets 32.

Furthermore, the separating arrangement 10 comprises a control device 40. With the control device 40, the electric current in the coil element 36 can be controlled. When the coil element 36 is subjected to an electric current of a first polarity, the connecting element 20 is moved from the first position to the second position. When the coil element 36 is subjected to a current of a second polarity, the connecting element is moved from the second position back to the first position.

Fig. 2 shows a circuit arrangement of the control device 40. The control device 40 comprises a bridge circuit 42, which is formed as H-bridge or full bridge. The bridge circuit 42 comprises the semiconductor switching elements, which are formed for example as transistors or IGBTs, and each comprising an inversely connected diode 46. Furthermore, the bridge circuit 42 comprises a capacitor 48, which is fed via a precharging device 50. By the bridge circuit 42, the electric current through the coil element 36 can be easily adjusted.

Fig. 3 shows the curve 52 of the position p of the movable contact element 16 as a function of the time t. During operation of the adjusting device 18, the connecting element 20 is to be controlled in such a way that the movable contact 16 is initially accelerated starting from the first position into the second position. Before reaching the second position, the speed v of the second contact element must be reduced. This is in Fig. 4 shown in the course 54. As a result, it can be prevented that the connecting element 20 or the retaining anchor 26 abuts in the holding yoke 22 in the second position. For this purpose, the electric current flowing through the coil element 36 is first increased. Subsequently, the polarity of the electric current is reversed, whereby one of the moving speed v of the movable Contact 16 oppositely directed braking force is generated. The time profile of the electric current I through the coil element is through the curve 56 in Fig. 5 shown. Fig. 6 shows in the course 58 the electrical voltage U across the capacitor 48.

Fig. 7 shows the separating arrangement 10 in a further embodiment. The disconnect assembly 10 includes a emergency switch element 60. The emergency switch element 60 may comprise a pyroelement or a tensioned spring. In an emergency, ie in the event of a failure of the electromagnetic control device 28, the connecting element 20 can be moved from the first position to the second position with the aid of the emergency switching device 60. Thus, the electrical contacts 14, 16 can be closed.

Finally shows Fig. 8 a further embodiment of a separating arrangement 10. The separating arrangement 10 shown here comprises two vacuum interrupters 12, 12 ', each, as previously in connection with Fig. 1 explained, with an adjusting device 18 and 18 'are connected. 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 device 18' can be controlled. In this case, by controlling the coil elements 36, 36 'of the control device 40, the electromagnetic actuating devices 30, 30' of the first actuating device 18 and the second actuating device 18 'can be switched in opposite directions. Due to the impulse neutrality, a good mechanical stability can be achieved.

Claims (9)

1. Actuating apparatus (18) for a vacuum interrupter (12) comprising

   - a connecting element (20), which is connectable to an electrical contact (16) of the vacuum interrupter (12), and

   - an electromagnetic actuating device (28) for moving the connecting element (20) between a first position and a second position,

   - a retaining yoke (22), relative to which the connecting element (20) is moveable, and which comprises a first magnet element (24), wherein

   - the first magnet element (24) brings about a first magnetic circuit and a second magnetic circuit in the retaining yoke (22), and

   - a ferromagnetic retaining armature (26), which is arranged on the connecting element (20), wherein

   - the retaining armature (26) is located in the first magnetic circuit in the first position of the connecting element (20) and in the second magnetic circuit in the second position of the connecting element (20), and wherein

   - the connecting element (20) is held stably in the first position and in the second position by a respective magnetic force between the retaining yoke (22) and the retaining armature (26),

   characterized in that

   - the electromagnetic actuating device (28) has a second magnet element (30) and a coil element (36) which is moveable relative to the second magnet element (30) and which is connected to the connecting element (20).
2. Actuating apparatus (18) according to claim 1, characterized in that the first and second magnet elements (24, 30) are formed integrally as a magnet apparatus.
3. Actuating apparatus (18) according to one of the preceding claims, characterized in that the retaining armature (26) and the coil element (36) are formed integrally as a coil apparatus.
4. Disconnecting arrangement (10) for disconnecting an electrical circuit, comprising

   - at least one vacuum interrupter (12), which has two electrical contacts (14, 16), and

   - at least one actuating apparatus (18) according to one of Claims 1 to 3, wherein the connecting element (20) of the at least one actuating apparatus (18) is connected to one of the contacts (14, 16) of the at least one vacuum interrupter (12) in such a way that the contacts (14, 16) are open in the first position of the connecting element (20) and are closed in the second position of the connecting element (20).
5. Disconnecting arrangement (10) according to Claim 4, characterized in that the disconnecting arrangement (10) comprises a control device (40) for controlling an electric current flowing through the coil element (36) of the at least one actuating apparatus (18), said control device being designed to reduce the electric current flowing through the coil element (36) if the connecting element (20) draws close to the first or second position.
6. Disconnecting arrangement according to Claim 4 or 5, characterized in that the control device comprises a bridge circuit comprising semiconductor switches.
7. Disconnecting arrangement (10) according to one of Claims 4 to 6, characterized in that the disconnecting arrangement (10) has a damping element for reducing a movement velocity of the connecting element (20).
8. Disconnecting arrangement (10) according to one of Claims 4 to 7, characterized in that the disconnecting arrangement (10) has an emergency switching element (60) for closing the contacts (14, 16) of the vacuum interrupter (12).
9. Disconnecting arrangement according to one of Claims 4 to 8, characterized in that the disconnecting arrangement (10) comprises two actuating apparatuses (18, 18') and two vacuum interrupters (12, 12'), wherein the control device (40) is designed to control the electric current flowing through the coil element (36) of the first of the two actuating apparatuses (18) and the electric current flowing through the coil element (36') of the second of the two actuating apparatuses (18') in a manner temporally offset with respect to one another.

Images