JP2006516799A - Electromagnetic drive for switchgear - Google Patents

Abstract

A drive unit (2), a magnet body (6), an armature (8) arranged at least partially movably in the magnet body, at least one drive magnet (5) for generating a permanent drive magnetic field; An electromagnetic drive device for a switch having at least one conductor (10) extending at least partially in the drive magnetic field and provided with a holding unit (3) for holding the armature in at least one terminal position (1) is improved in such a way that it is fixed in its end position in a particularly simple manner and that simple control is possible. For this purpose, the holding unit has at least one soft magnetic movable part (15) rigidly coupled to the armature, which closes the gap (18) for the permanent holding magnetic field at each end position of the armature, This holding magnetic field is generated by at least one holding magnet (16) irrespective of the driving magnetic field, and this holding magnet has a separating coil (17) that is fed independently of the conductor in order to displace the armature from the end position. It is attached.

Description

  The present invention comprises a drive device, the device being at least partially a magnet body, an armature disposed at least partially movably in the magnet body, at least one drive magnet generating a permanent drive magnetic field, and In particular, the present invention relates to an electromagnetic drive device for a switch in the medium voltage field, in which a holding unit for holding an armature at at least one terminal position is provided.

  Such an electromagnetic drive is known, for example, from DE 198 15 538 A1. This apparatus includes a three-phase linear motor composed of a plurality of motor modules. The motor module includes a predetermined number of fixed motor coils and a movable part with a permanent magnet guided so as to be movable in the longitudinal direction. A magnetic field is generated with the excitation of the motor coil, and a permanent magnet of a movable part is arranged in the magnetic field. The movable part coupled to the movable contact of the switch via the open / close rod is driven by the generated Lorentz force. In order to insert the vacuum circuit breaker, the movable contact is pressed against the fixed contact of the switch by a three-phase linear motor, and the movable part reaches the end position.

  From International Publication No. 95/07542, an electromagnetic driving device having a frame-shaped closed yoke made of a soft magnetic material formed by laminating thin plates to prevent eddy current is known. The yoke has a void, and an armature made of a soft magnetic material is guided in the void so as to be movable between both terminal positions. At each end position of the armature, one end surface of the armature contacts the soft magnetic yoke, and a gap is formed between the other end surface opposite to the contact portion of the armature and the frame-shaped closed yoke. Coils that respectively surround both end faces of the armature are fixed in the space of the yoke. There is a permanent magnet that generates magnetic flux between the two coils. Based on the air gap, the armature is fixedly held at each end position. By energizing the coil surrounding the gap side end face of the armature, in order to reduce the magnetic resistance, a magnetic flux large enough to move the armature away from the yoke and move it to the stable second terminal position while closing the gap Occurs within. At its end position, the armature contacts the yoke at the end face that previously bounded the air gap. Since the armature is fixed even at the second end position, the exciting current of the coil can be interrupted.

  Both known electromagnetic drives described above are based on different physical effects. That is, the electromagnetic drive device of German Patent Application No. 19815538 uses a so-called Lorentz force generated during the movement of charged particles in a magnetic field to generate a drive action. In contrast, the electromagnetic drive of WO 95/07542 is based on the physical action in which the magnetic field propagates in a particularly high permeability material, i.e. a material with a small magnetoresistance. As the armature moves, the entire device moves from a high magnetic potential energy failure state to a good energy state where the air gap is closed and the magnetic flux is transmitted through only a material with a small magnetoresistance. The force to move the device to a good energy state is generated by gradient formation. A drive device based on such an effect is also called a reluctance drive device.

  An electromagnetic drive based on the Lorentz force has great mobility and is controlled in a simpler manner, i.e. with a current guided through a magnetic field. However, this drive device has neither a stable end position nor an intermediate position and must be fixed to each end position by auxiliary means if necessary. For this purpose, springs, claws and the like are usually employed, and increasing the force requires a large cost. The reluctance type drive device is generally superior in that it can be stably fixed at the end position. However, it has the disadvantage that the force-stroke characteristic curve is rather non-linear, which is cumbersome or affects the holding force load at the end position or the load in the structure space.

  SUMMARY OF THE INVENTION An object of the present invention is to improve an electromagnetic drive device of the type described at the beginning so that it can be fixed to its terminal position with a simple structure, and simple control of drive motion can be maintained.

  This object is based on the present invention, in which the holding unit has at least one soft magnetic movable part rigidly coupled to the armature, which closes the gap for the permanent coercive force at each end position of the armature, The permanent holding magnetic field is generated by at least one holding magnet irrespective of the driving magnetic field, and this magnet is provided with a separating coil that is fed independently of the conductor to displace the armature from the end position. Is done.

  The electromagnetic drive device according to the present invention has a drive unit and a holding unit, and the conductors or coils are fed independently of each other. Thus, the drive according to the invention can be controlled arbitrarily and meets almost all requirements. At the same time, electromagnetic holding takes place at at least one end position of the armature of the drive, so that an expensive and maintenance-free mechanical holding unit is not required. By closing the air gap provided in the holding unit, the magnetic resistance against the holding magnetic field generated by the holding magnet is reduced or minimized, so that the movement of the armature from the end position resists the reluctance force of the holding unit. This is possible for the first time. At the end position of the armature, the movable part contacts, for example, a location that limits the gap of the holding unit, so that this location forms a stopper that prevents further movement of the armature.

  Furthermore, the armature, and thus the movable part, may be secured to the movable contact of the vacuum valve. At the contact position of the vacuum valve, the movable contact contacts the fixed contact of the vacuum valve. The final position of the armature is determined with the contact of the contacts based on the solid bond with the armature. When the armature is in this end position, it is not necessary for the movable part to be in contact with the soft magnetic part that bounds the gap of the holding unit. The moving part can be separated from the point that bounds the gap of the holding unit.

  For example, when the armature in the range of one end position is moved from the drive unit conductor on the one hand and the separation coil on the other side of the holding unit on the other hand, for example, the holding magnetic field is neutralized by the separation coil. By generating the pulling-off magnetic field, the action of the reluctance force during the driving operation, that is, the action of the holding magnet can be almost completely canceled out.

  Further, the present invention is characterized in that the movable part is formed of a material having a slight magnetic resistance compared to the gap. In this case, any ferromagnetic material such as iron, mu metal, nickel iron alloy, etc. can be used. A soft magnetic material means a material that loses its magnetic properties after the magnetic field that generates the magnetic properties is interrupted. Thus, soft magnetic materials exhibit an elongated hysteresis curve and thus a slight residual magnetization.

  The holding body may be composed of two holding bodies and arranged on both sides of the movable part. In this advantageous embodiment of the invention, the movement space of the moving part rigidly coupled to the armature is limited on both sides, so that the end positions on both sides of the armature are determined. Accordingly, in a preferred embodiment of the present invention, when the armature is used to drive a vacuum valve, the contact position of the vacuum valve that allows current flow through the vacuum valve and the spaced separation of the contacts. A position exists.

  A means for interrupting the magnetic flux may be provided between the holding unit and the drive unit. By this means, the holding unit and the driving unit are magnetically separated from each other. By this means, it is possible to avoid further adverse effects due to the superimposing action of the driving magnetic field, and thus the holding magnetic field and further the separating magnetic field. A nonmagnetic substance having a magnetic permeability of 1 or less, such as air or aluminum, is suitable as the magnetic flux blocking means.

  In an advantageous embodiment of the invention, a holding magnet and a separating coil are arranged on the holding body. Thus, the holding magnet and the separating coil are held by a holding body that cannot move during driving, thereby preventing the movement of these sensitive parts, for example when the vacuum valve is turned on. In this advantageous embodiment, the maintenance sensitivity of the electromagnetic drive can be reduced.

  The armature may have a coil holder made of an insulating material, and the conductor may be arranged as a winding on the coil holder. In this embodiment, the electromagnetic drive is a lift drive. The coil holder is formed, for example, as a tube member, in other words, in a tubular shape.

  In another advantageous embodiment of the invention, the magnet body consists of a drive magnet and a soft magnetic yoke, the drive magnetic field is transmitted through a recess provided in the magnet body, and the conductor of the movable part is at least partially in the recess. Arranged. In this embodiment, the coil moves and the sensitive and heavy permanent magnets are fixed in the magnet body. Since the permanent magnet is immovable, the lifetime can be extended or the maintenance sensitivity can be reduced as described above. Along with the coil movement, this drive can also be called a moving coil type.

  The electromagnetic drive unit according to the present invention is configured to generate a predetermined time-dependent control signal, a control signal to a control unit, a current amplification operation unit last stage for supplying power to a conductor according to the control signal, and a corresponding separating coil. It is preferable to have at least one current amplification coil termination stage that supplies power in accordance with. The final stage used in this embodiment is used to amplify the output signal of the control unit. The output signal of the unit is not sufficient to feed the coil or conductor. Control data corresponding to each actual requirement is stored in the control unit, and a time-dependent control signal is generated by the model. This control enables a particularly simple setting of an arbitrary force / stroke characteristic curve of the electromagnetic drive device.

  The invention further relates to a method for controlling an electromagnetic drive device according to the invention in which the holding coil is fed in response to the current of the conductor. Thus, mutual interference is almost completely eliminated.

  Embodiments and advantages in accordance with other objects of the present invention will become apparent from the description of the embodiments of the present invention with reference to the following drawings. In each figure, the same portions are denoted by the same reference numerals.

  FIG. 1 shows a cross-sectional view of an embodiment of an electromagnetic drive device 1 according to the present invention. This device 1 has a drive unit 2 and a holding unit 3, both units 2, 3 being connected to each other via insulating means formed as an annular aluminum block 4. The insulating means is provided to block the magnetic field of the drive unit 2 from the magnetic field of the holding unit 3 or to block in the reverse direction.

  The drive unit 2 includes a magnet body, and the magnet body includes a drive magnet 5 that generates a permanent drive magnetic field and a soft magnetic yoke 6 that is firmly coupled to the magnet 5. An annular recess 7 is provided in the magnet bodies 5 and 6, and a part of the armature 8 extends into the recess 7. The armature 8 has a cup-shaped coil holder 9 made of an insulating material, and the tubular portion of the holder 9 supports a conductor winding. This conductor winding forms a drive coil 10.

  The armature 8 is firmly coupled to the motion transmission rod 12 via the cross beam 11 of the coil holder 9. The rod 12 is supported in the electromagnetic drive device 1 by an ordinary bearing so as to be movable in the longitudinal direction.

  The holding unit 3 has a soft magnetic holding body 14 composed of two holding bodies, and each holding body 14 is disposed on both sides of a movable part 15 made of a soft magnetic material. The movable part 15 is rigidly coupled to the motion transmission rod 12 and is therefore rigidly coupled to the armature 8. In this embodiment, ferromagnetic steel is used as the soft magnetic material for the holder 14 and the movable part 15. There are holding magnets 16 on each side of each holding body 14 and thus on the movable part 15. The magnet 16 generates a holding magnetic field extending in the movement direction of the armature 8. The holding magnet 16 is concentrically surrounded by a separating coil 17. The gap 18 is bounded by the movable portion 15 and the holding body 14, and the holding magnetic field is transmitted through the gap 18 mainly in the axial direction in the movement direction of the movable part 15.

  The drive unit 2 generates a drive motion based on the Lorentz force. For this purpose, an axial driving permanent magnetic field is generated in the longitudinal direction of the armature 8. The magnetic field lines are generated in the drive magnet 5 and guided through the soft magnetic yoke 6. The magnetic field is transmitted laterally through the coil 10 of the armature 8 disposed in the recess 7 of the magnet body. Therefore, when the coil 10 is supplied with power, a lift movement of the armature 8 occurs, and this movement is transmitted to the movable part 15 via the movement transmission rod 12. Accordingly, the movable part 15 moves toward one of the holding bodies 14 in accordance with the direction of movement, and as a result, the gap 18 between the movable part 15 and the holding body 14 is reduced. The reduction of the gap 18 reduces the magnetic resistance against the axial holding magnetic field generated by the holding magnet 16. This effect is attributed to the fact that the holding body 14 is made of a ferromagnetic material, that is, a material having a transmittance much higher than 1, whereas the gap 18 is filled with air, that is, a substance having a relative transmittance of 1. When the movable part hits one holding body 14, the armature 8 reaches one terminal position and is held at this position by the reluctance force generated by the gap reduction. In order to separate the armature 8 from the end position, the separating coil 17 surrounding the holding magnet 16 with which the movable part 15 is in contact is excited. The action of the holding magnet 16 is weakened or canceled by the separating magnetic field generated by the separating coil 17, and therefore the armature 8 can be moved away from the terminal position by the drive unit 2. The armature 8 moves in the reverse direction until the armature 8 hits the holding body 14 on the opposite side and reaches the second terminal position. Even at this position, since the air gap 18 located on the side in the movement direction is closed, the magnetic resistance to the holding magnetic field is minimized.

  FIG. 2 schematically shows a control unit 19 of the electromagnetic drive device of FIG. This unit 19 has an interface 20 which converts the input or cut-off signal 21 to be input into a control input signal that is received by the control device 20. A predetermined signal model is stored in the storage area of the control device 22 in the form of signal strength with respect to time. In accordance with the selected predetermined signal model, the control unit 19 controls the holding magnet operation unit final stage 23 with the time-dependent current value 24. As a result, the current value 24 of the control unit 19 is reinforced at the last stage 23 of the holding magnet operation unit and is supplied to the separating coil 17 of the holding unit 3.

  The control device 22 is further connected to a current regulator 25, which compares the set current value 26 received from the control device 22 with an actual current value 27 generated at the output end of the conductor operation unit final stage 28. When the set current value 26 and the actual current value 27 coincide, a progress signal 29 is generated. The actual course state (Weglage) is detected by a measurement system (not shown). Therefore, the adjustment of the control device enables a particularly accurate adjustment of the force / stroke characteristic curve of the electromagnetic drive device.

  Within the framework of the present invention, the auxiliary adjustment may be omitted, and the conductor operation unit final stage 28 may be directly controlled by the control device 22 as well.

  The control device 22, the conductor operation unit final stage 28, and the holding magnet operation unit final stage 23 are connected to a power source 31 schematically shown in FIG. The power source 31 supplies energy 30 necessary for control.

Sectional drawing of the Example of the electromagnetic drive device based on this invention. The control block diagram of the electromagnetic drive device in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electromagnetic drive device, 2 Drive unit, 3 Holding unit, 5 Drive magnet, 6 yoke, 8 Armature, 10 Conductor, 14 Holding body, 15 Moving part, 17 Pull-off coil, 18 Air gap, 22 Control unit, 23 Holding Magnet operation part last stage, 28 conductor operation part last stage

Claims (9)

A drive unit (2), the unit (2) having a magnet body (6), an armature (8) arranged at least partially movable in the magnet body (6), and a permanent drive magnetic field; At least one drive magnet (5) generated and at least one conductor (10) extending at least partially in the drive magnetic field for holding said armature (8) in at least one terminal position In an electromagnetic drive device (1) for a switch provided with a holding unit (3),
The holding unit (3) has at least one soft magnetic movable part (15) rigidly coupled to the armature (8), the part (15) being permanent at each end position of the armature (8). To close the gap (18) for the holding magnetic field, the magnetic field is generated by at least one holding magnet (16) irrespective of the driving magnetic field, and causes the magnet (16) to displace the armature (8) from the end position. An electromagnetic drive device, characterized in that a separating coil (17) to be fed regardless of the conductor is attached.   The holding unit (3) has a holding body (14) coupled to a magnet body, and a gap (18) is formed between the holding body (14) and the movable part (15). The electromagnetic drive device according to claim 1.   The electromagnetic drive device according to claim 2, wherein the holding body (14) is formed of two holding bodies and is arranged on both sides of the movable part (5).   The electromagnetic drive device according to claim 2 or 3, wherein the holding magnet (16) and the separating coil (17) are arranged on the holding body (14).   5. The electromagnetic drive device according to claim 1, wherein means for interrupting magnetic flux is provided between the holding unit and the drive unit. 6.   The armature (8) has a coil holder (9) made of an insulating material, the conductor of which is formed as a winding (10) arranged on the coil holder (9). The electromagnetic drive device according to one of 5.   A magnet body consists of a drive magnet (5) and a soft magnetic yoke (6), and a drive magnetic field permeate | transmits the recess (7) provided in the magnet body, and conductor (10) in this recess (7) 7. The electromagnetic driving device according to claim 1, wherein the at least part of the electromagnetic driving device is arranged.   A control device (22) for generating a predetermined time-dependent control signal, a current boosting operation unit last stage (28) for supplying power to the conductor (10) in relation to the control signal, and a corresponding separating coil (17) 8. The electromagnetic drive device according to claim 1, further comprising at least one current-enhancement operation unit last stage (23) for supplying power in relation to the control signal.   9. The excitation coil (17) is excited in relation to the current of the conductor (10) so that the electromagnetic drive device (1) exhibits a predetermined force / stroke characteristic curve. A method for controlling an electromagnetic drive device according to any one of the above.

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