DE19848551A1 - Drive for the movable contact piece of an electrical switch - Google Patents

Abstract

The invention relates to a drive for the movable contact piece of an electrical switching device, for. B. a high-voltage circuit breaker, in particular an SF6 circuit breaker, a load break switch or the like., With a fixed part and a movable part connected to the movable contact piece. The fixed part of the drive (12) should be a cylindrical tube, on the inside of which coils (16, 17, 18) are arranged to produce a traveling field, whereas the fixed part as inside the tube (12) and inside the coils (16 , 17, 18) sliding armature (20) is formed, which is driven by the traveling field for actuating the movable contact piece of a switching device.

Description

The invention relates to a drive for the movable contact piece of an electrical switching device, for. B. a high-voltage circuit breaker, in particular an SF ₆ circuit breaker, a load break switch or the like.

Such drives can be hydraulic, especially in circuit breakers Actuate moving contact piece. An energy store is provided for this purpose hen, after a switch-off sequence in which it at least largely discharged that will be tensioned again. The energy storage device can be used as a gas spring energy storage device cher formed, which is divided by a movable partition, wherein compressible gas on one side of the partition and on the other side the intermediate wall hydraulic fluid is present. For charging the energy storage the gas is compressed by means of pumped hydraulic fluids; on an off switching sequence, the gas relaxes and drives the hydraulic fluid into a corresponding The piston-cylinder arrangement with which the movable contact piece is actuated.

Instead of a gas accumulator, a mechanical spring accumulator can also be used are, the spring arrangement tensioned in the same way as the gas, d. H. to is squeezed; when switching off, the spring energy is transferred to the Hy Draulikfluid transmitted, whereby the piston-cylinder assembly is actuated again.  

Particularly in the case of medium-voltage switchgear, that is switchgear between approx. 12 kV to 36 kV, pure spring accumulators are also provided, whose spring energy directly or via a gear on the movable contact piece after loosening a ver latch arrangement for switching off is transmitted.

Disconnector, e.g. B. switch disconnectors, in which a circuit is featured under load must be taken, are usually operated by means of a spring accumulator arrangement. For earthing switches or switches only to achieve a separation distance that is not Switching under load, electric motors can also be used, since these are mostly only a rotating type, at least slower than the circuit breaker need drive with lower force density.

Those drives that are operated with a hydraulic system are reliable sig; however, if such a drive is used for a long time in the hydraulic system Leakages can occur, are special measures to monitor you hydraulic system necessary. With so-called gas spring accumulators is beyond from also check the tightness of the gas spring, which is mostly when charging the Gas storage spring is made automatically. The drive is in spring-loaded mechanisms mechanically complex; special attention should be paid to maintenance Spring accumulators, also for drives, where a spring arrangement acts on the movable contact piece without the interposition of hydraulic fluid, the wear is relatively high.

A magnetic drive has recently been developed in which a closed Yoke is provided in which an anchor can move; this magnetic drive al However, because of the small armature stroke is mainly for vacuum switching provided.

The object of the invention is to provide a drive of the type mentioned in the introduction, in which, with optimal control, the structure is simple, the wear and the goods are low and for which special monitoring devices such as those at hydraulic drives are required can be avoided.  

This object is achieved in that the fixed part cylindrical tube, on the inside of which coils for generating a magnetic Are arranged moving field is formed, whereas the movable part as in Within the tube movable sliding anchor is formed by the wander field is driven.

The advantage of such an arrangement according to the invention is that each after switching task the fixed part can remain unchanged, whereas that moving part is modified.

A first embodiment of the invention can be that the anchor, that is the movable part has at least one permanent magnet, the north and South poles are aligned axially.

If two or more permanent magnets are provided, then these can be used as Ring magnets must be arranged so that the poles of the same name face each other.

An iron ring can be arranged between two permanent magnets.

This ensures that the magnetic field lines through the fixed part and in addition by the permanent magnet with the connected Ab cut the iron parts run through, especially on the webs between two grooves each have a flow enhancement due to a field line concentration finds. This creates a high force density, so that a structurally short to drive can be produced.

If the principle of synchronism plus a transverse flux anchor is used, then the highest power exploitation is generated.

The manufacture of such an arrangement is very simple; the moving part exists from a guide rod made of antimagnetic material, on which the axial direction magnetized permanent magnet disks alternating with iron disks  are brought. These iron disks also serve to reinforce the river and cause flow enhancement in the air gap.

There is also the possibility of inserting the coils into the grooves in a ring shape, so that the coils surround the movable part in a ring. Thereby, the same phases connected.

According to a further embodiment of the invention, the anchor has at least two permanent magnets, whose north and south poles alternate radially outwards and are directed inwards. Here, too, the anchor can have a guide rod sen, on which the permanent magnets are lined up in disk form. In the radial The permanent magnets are magnetized at such a distance from one another orders that a desired magnetic induction curve, e.g. B. a sinusoidal Course along the axis is achieved.

If the permanent magnets are plastic-bonded and have a low flux density have, they can be used especially for switch disconnectors or disconnectors be det.

In the arrangements given above, the iron sections lead with introduced Movement to changes in inductance within the stator coils leading to position ser version can be used.

The invention is particularly simplified in that both the stator as well as the anchor, that is to say the movable part, composed of segments could be. A different one is used to achieve different force densities Number of segments for the moving part mechanically arranged one behind the other net; in the same way, to achieve different travels, that is Drive strokes, a different number of stator segments mechanically behind be arranged to each other. If the segment length is s and the achievable force with a segment for the moving part is designated K1, then the entire Anchors have a length of n × s and the stator of m × s, with n and m below mean different segment numbers; the number of segments in the stator would be greater than that  the one in the anchor. The total travel distance is then (m - n) × s and the force density n × K1.

If the disc-shaped permanent magnets, which are radially magnetized, differ are lined up with disc-shaped iron sections, then they lead egg Sections with initiated movement to changes in inductance within the Stator coils that can be used for position detection.

Further advantageous refinements and improvements of the invention are the see further subclaims.

The arrangement with permanent magnets accordingly works according to the synchronous principle zip, where using the disc-shaped permanent magnets a high force yield and when using plastic-bonded permanent magnets lower flux density an average power yield is achieved.

If the so-called asynchronous principle is used, in which the anchor acts as an anchor rod is designed and serves as a short-circuit cage, the power yield is comparatively low and the so-called rise time longer, so that such a drive construction for Disconnector and / or earth switch drives can be used.

The particular advantage of the configuration according to the invention is that a Uniform fixed part, i.e. a uniform stator for all switching tasks can be used; the adaptation to the respective switching device and the respective Switching task is achieved by suitable design of the moving part.

The fact that a further modularization only includes the individual segments, the number of stator and armature segments determines the achievable force and the ver driveway.

Of course, it is also possible to incorporate the invention specified above put and use when the inside part is the fixed part, whereas the tubular outer part is movable; the inside can  fixed part also carry the coils; however, there is a cheaper solution in that the coils are arranged on the inside of the tubular part.

Using the drawing, in which some embodiments of the invention are shown the invention and further advantageous refinements and improvements gene explained in more detail and described.

Show it:

Fig. 1 is a sectional view through a first embodiment of a drive OF INVENTION to the invention,

Fig. 2 is a perspective view of a fixed part for the drive of FIG. 1,

FIGS. 3 and 4 different types of armatures,

Fig. 5 shows another embodiment of a drive according to the invention,

Fig. 6 shows an embodiment for an anchor, and

Fig. 7 shows another embodiment of the anchor.

The drive 10 shown in Fig. 1 for a circuit breaker 11 shown only schematically has a fixed part 12 in the form of a cylindrical raw res, in which grooves 13 , 14 , 15 and 13 a, 14 a and 15 a are introduced, in which there are coils 16 , 17 and 18 , the coil sections of which are designated 16 a, 16 b, 17 a, 17 b and 18 a, 18 b. In the coil sections 16 a, 17 a and 18 a, the currents flow perpendicular to the plane of the drawing away from the viewer, whereas in the coil sections 16 b, 17 b and 18 b the currents flow perpendicular to the plane of the drawing onto the viewer.

Within the cylindrical tube is a movable part 20 , which has a rod-shaped core 21 made of soft iron, on which two permanent magnets 22 and 23 are arranged, which are at a distance D from one another. Within the area located by the distance D, a soft iron disk 24 is net angeord.

FIG. 3 shows such an embodiment. The two disc-shaped permanent magnets 22 and 23 are located on the rod-shaped core 20 , the two permanent magnets being assigned to one another in such a way that the permanent magnet 22 is oriented with its south pole towards the core 21 and the permanent magnet 23 with its north pole towards the core 21 ( FIG. 1 ). The distance D is chosen so that a suitable distribution of the radial magnetic induction is generated. If the distance D = 0, a rectangular course would be generated; depending on the distance, a sinusoidal curve can be achieved.

The iron disc 24 , the axial thickness of which is small compared to the axial thickness of the permanent magnets, essentially causes a type of asymmetry with which the position positions of the armature 20 can be detected.

In Fig. 1, six grooves are illustrated for a total RECORDING of the coils; Of course, more grooves can be arranged; in the same way, the anchor 20 can carry more than two permanent magnets. This configuration is a three-phase arrangement of the coils, which is preferred because a large number of control components are readily available and known for control purposes.

Fig. 2 shows a perspective view of the fixed member 12 in the form of a cylindrical tube.

If the coils 16 , 17 and 18 are now actuated in a suitable manner, then they generate a traveling field, the closed field lines of which are designated by the reference number 30 ; these field lines run from the fixed part into the permanent magnets, through the core 21 again through the permanent magnets back into the fixed part 12 .

The permanent magnets 22 and 23 can be designed as conventional permanent magnets with a high flux density, then a drive force F (see FIG. 1) can be generated with a fixed part of the same design, which is expedient for circuit breaker drives, in particular SF ₆ switch drives. If the permanent magnets are plastic-bonded and have a lower flux density, then sol drives can be used to drive load switches and disconnectors.

The principle just described uses the so-called synchronous principle. Of course, there is also the option of using the asynchronous principle. For this purpose, e.g. B. an electrically conductive hollow anchor rod 31 is used in the interior of the fixed part, which serves as a short-circuit cage, and induced in the eddy currents, which are opposite to the traveling field. Such drives or Ausge events with low power yield can be used as a disconnector or earthing switch drives.

This ensures that for the purpose of adaptation to the corresponding switching task leave the fixed part and only use the moving parts accordingly got to. This means a great simplification, since only the moving parts are left on the switching task must be adjusted.

FIG. 5 shows another embodiment of the invention. It has a stator 50 , which is of hollow cylindrical design, with grooves 51 , 52 , 53 and 54 , 55 and 56 on the inner surface thereof. . . are introduced. In the grooves 51 to 53 there are coils 57 , 58 and 59 , in which the current flows into the drawing plane in the arrangement shown in FIG. 5.

These coils are annular and are assigned to the individual phases R, S and T, the coil 57 being assigned to the R phase, the coil 58 being assigned to the S phase and the coil 59 being assigned to the T phase.

In the grooves 54 , 55 and 56 are the coils 57 to 59 corresponding coils 60 , 61 and 62 , in which the current flow is selected so that the current flows out of the plane of the drawing, in the illustration chosen in FIG. 5.

Phase R is assigned to coil 60 , phase S to coil 61 and phase T to coil 62 .

The coils 57 and 60 are connected in a corresponding manner so that the current flow is achieved, as shown in FIG. 5; 58 and 61 and 59 and 62 .

The movable part is an armature 65 , which has a non-magnetic guide rod 66 on which disk-shaped or ring-shaped permanent magnets 67 and 68 are arranged, the permanent magnets being axially aligned and the poles of the same name, here the south poles of the two permanent magnets 67 and 68 face each other. The north pole of the permanent magnet 67 is assigned an annular iron disk 69 ; Between the two permanent magnets 67 and 68 there is a further iron disk 70 and an iron disk 71 is also assigned to the north pole of the permanent magnet 68 .

Due to the structural design, the magnetic lines run as shown in FIG. 5: the flux lines 72 generated by the permanent magnet 67 run in the permanent magnet from the south pole to the north pole, from there through the iron disk 69 and through the air gap 73 into the stator and back into the stator to the iron part 70 and again to the south pole of the permanent magnet 67 .

The field lines 74 generated by the permanent magnet 68 run inversely through the permanent magnet 68 . In other words, the field lines 72 run counterclockwise in the position and representation shown and the field lines 74 run counterclockwise.

By suitable control of the coils 57 , 58 and 59 or 60 , 61 and 62 and other coils, a traveling field is generated which drives the armature 65 , that is to say the movable part 65 , in the direction of the arrow F, thereby making it movable Contact piece can be driven.

Fig. 6 shows a perspective view of the armature 65th One can see the rod 66 , which is hollow here, on which the iron disk 71 , the permanent magnet 68 , the iron disk 70 , the permanent magnet 67 and the iron disk 69 are applied.

Figs. 7 shows an alternative embodiment of the anchor; the iron rings 80 , 81 , 82 are designed as pole pieces for the permanent magnets.

One can form segments for the stator, such a segment containing the grooves 51 , 52 and 53 with the corresponding coils 57 , 58 and 59 , and a further segment with the grooves 54 , 55 and 56 and the coils 60 , 61st and 62 ; from this segment arrangement any number of segment parts can be combined in one unit. The stator can also be assembled in the same way; on the anti-magnetic guide rod 66 , the different rings are simply placed in a corresponding manner and in a corresponding number, of which a permanent magnet and an associated iron part each form a unit; only two types of elements or segments would then have to be provided for producing a stator with a plurality of permanent magnets.

Claims (13)

1. Drive for the movable contact piece of an electrical switching device, for. B. a high-voltage circuit breaker, in particular an SF ₆ power switch, a switch disconnector or the like., With a fixed part and a movable part connected to the movable contact piece, characterized in that the fixed part ( 12 ) is a cylindrical tube, at its Inside coils ( 16 , 17 , 18 ) are arranged to generate a magnetic traveling field, is formed, whereas the movable as within the tube ( 12 ) sliding at ker ( 20 , 31 ) is formed, which is driven by the traveling field. 2. Drive according to claim 1, characterized in that the armature at least has a permanent magnet, the north and south poles alternately to the outside eat and face inwards. 3. Drive according to claim 2, characterized in that at two or more Permanent magnets are arranged as ring magnets so that they have the same name Poles face each other. 4. Drive according to claim 3, characterized in that between two Permanent magnet an iron ring is arranged. 5. Drive according to claim 1, characterized in that the armature ( 20 ) we at least has two permanent magnets, the north and south poles of which are alternately directed outwards and inwards. 6. Drive according to one of claims 2 to 5, characterized in that the armature ( 20 ) has a guide rod ( 21 ) on which the permanent magnets ( 22 , 23 ) are lined up in disk form. 7. Drive according to one of the preceding claims, characterized in that the permanent magnets ( 22 , 23 ) are arranged at such a distance from one another that a desired magnetic induction curve, for. B. a sinusoidal curve, ent long axis is achieved. 8. Drive according to one of the preceding claims, characterized in that plastic-bonded permanent magnets of low flux density are provided. 9. Drive according to one of the preceding claims, characterized in that in the region between the permanent magnets ( 22 , 23 ) a disc ( 24 ) made of soft magnetic iron is used, which is used for determining the position. 10. Drive according to one of the preceding claims, characterized in that the inside of the tube ( 12 ) grooves ( 13 , 14 ...) are introduced, in which the coils ( 16 , 17 , 18 ) are inserted. 11. Drive according to claim 10, characterized in that three coils ( 16 , 17 , 18 ) are provided. 12. Drive according to one of claims 1, 9 and 10, characterized in that the armature is designed as a tubular armature rod ( 31 ) and serves as a short-circuit box fig. 13. Drive according to one of the preceding claims, characterized in that the tubular part ( 12 ) is the movable part and the armature ( 20 , 31 ) is the fixed part.