MAGNETKERN SOWIE DROSSEL BZW. TRANSFORMATOR MIT EINEM SOLCHEN MAGNETKERN

Magnetic core and inductor or transformer with such a magnetic core

description

The invention relates to a magnetic core for a three-phase choke or a three-phase transformer according to the preamble of claim 1. Furthermore, the invention relates to a three-phase choke or a three-phase

Transformer with such a magnetic core. A magnetic core according to the

Preamble of claim 1 is known for example from DE 10 2012 207 557 AI.

The prior art magnetic core comprises three magnetic leg, which are each adapted for receiving a first, second and third electric winding. The first, second and third electric winding is in each case associated with a first, second and third electrical phase. To compensate for asymmetries in the three-phase system, the three magnetic leg are arranged in a star-shaped or triangular shape to each other. This should be advantageous over the previously popular series arrangement of the legs.

The three legs of the known throttle are connected to one another by a yoke which is formed star-shaped. Specifically, the yoke to a center, from which three magnetic connection legs extend in a star shape outwards. In this way, the three legs are star-shaped coupled together.

The star-shaped design of the yoke has several disadvantages. On the one hand for mounting the yoke on the legs of a precise alignment of the

Connecting leg of the yoke before connection of the yoke with the

magnetic legs required. On the other hand the coils of the inductor are on their longitudinal axial ends free largely because the connecting leg overlap only a small area of ​​the coils. Finally, the star-shaped design of the yoke affects the steadiness of the throttle. This is especially true if more identical reactors are to be stacked. This in turn requires a previous alignment of the orientation of the star-shaped yokes, in order to avoid tilting of the patch on a first throttle second throttle.

The object of the present invention is to provide a magnetic core which is easy to assemble, has an improved mechanical stability and / or provides good protection for the windings of a choke or of a transformer. It is another object of the present invention to provide a choke or a transformer with such a magnetic core.

According to the invention this object is achieved with respect to the magnetic core by the subject matter of claim 1 and in the H inblick the choke or the transformer by the subject matter of patent claim 14.

Thus, the invention is based on the idea of ​​a magnetic core for a

three-phase choke or a three-phase transformer having three

indicate winding limbs to receive electrical windings, wherein the coil legs are disposed substantially parallel to each other in a triangular shape. The winding legs are joined by an annular or convex polygon shaped yoke, which rests on the winding legs.

The arrangement of the winding leg in a triangular shape is achieved that asymmetries which occur for example in magnetic legs arranged in a row are avoided. The winding legs are arranged substantially parallel to each other, wherein the winding leg, in particular its longitudinal ends, span a triangular basic shape. In other words, the three winding legs form a cross-section of the

Magnet core, the corners of a triangle.

The ring-shaped or convex polygon shaped yoke facilitates the manufacture of the magnetic core. The relief is advantageously applied primarily in connecting the yoke with the winding legs.

When using a ring-shaped yoke, an alignment of the yoke with respect to the winding legs is not necessary. Rather, the annular yoke can be placed in any orientation on the winding leg and thus connect them. The ring-shaped or convex polygon shaped yoke also increases the stability of the magnetic core. This is especially true when multiple magnetic cores

be stacked. When stacking of magnetic cores having an annular yoke, there is a comparatively large surface contact between the stacked yoke. This increases the tilting stability.

Even when the convex polygon shape of the yoke, an alignment of multiple magnetic cores is not needed to each other to avoid tipping. This is because the polygon shape, a twisted arrangement of opposite or of stacked yokes can be dispensed with. Because of the polygonal shape are sufficiently large area shares above the other, so that tilting of the

is magnetic cores avoided. This makes it easier to install several magnetic cores in a housing.

Furthermore is achieved with the annular convex or polygonal yoke that a relatively larger portion of the coil is covered in the longitudinal axial direction by the yoke. To this extent, the yoke forms a protection for the windings of a choke, which is wound around the winding leg, from damage. Because the yoke forms a longitudinal axial barrier, so that a relatively larger portion of the winding is not readily accessible.

In the context of the present application is considered to be convex polygonal a component which is formed at least on a circumferential polygonal outer surface, wherein all interior angles of the polygonal shape are smaller than 180 °. As regularly polygornförmig a polygonal at least on one outer circumferential side member, the same side lengths and the same interior angle applies having. The

Polygon shape can be seen not only at an outer side in general. Rather, the yoke may also form a through opening, which may also be polygonal. In this case, the polygonal shape on an outer side of the yoke of the polygonal shape on the inside, that is, the polygonal shape of the

Through opening vary. For example, the yoke may total, that is, the outside looking be formed hexagonal and triangular

limit through opening.

Preferably, the yoke rests on the longitudinal ends of the winding legs. It is not excluded that an air gap is provided between the yoke and the longitudinal ends. It is essential in any case that a magnetic flux is maintained between the yoke and the winding legs.

In a preferred embodiment of the invention, the three yoke

Transverse connecting leg, on each transverse connecting leg connects two immediately adjacent winding limb. The

Cross-connection legs may be arcuate, particularly circular arc-shaped, or at least partially rectilinear. Preferably, the arcuate cross-connecting legs are curved such that all three transverse connecting arm together forming the annular yoke. at

rectilinear cross connecting legs is advantageously provided, that in each case two transverse connecting leg intersect in the region of a winding leg. In particular, two transverse connecting leg intersect respectively at the longitudinal ends of the coil leg or on an arcuate line on which all winding legs are arranged. In general, it can be provided that in an area between the three winding legs no

Crossing point of the cross-connecting leg is provided.

The transverse connecting leg may extend along a circumferential line, which is predetermined by the triangular arrangement of the winding legs. In the area of ​​the inner surface of triangular shape, which is determined by the winding leg, preferably is no connection between the cross-connection legs.

The direct coupling of two adjacent coil legs in each case by a transverse connecting leg also changes the magnetic flux within the

Magnetic core. This can have a positive effect on the function of a

affect three-phase AC reactor or a Dreiphasenwechselstrom- transformer. In particular, is achieved by the proposed inventions geometric design of the yoke that the

not meet magnet currents in a center of the yoke, but extending along the outer line between the winding legs. This affects the operation of the choke or transformer.

Concretely, it can be provided in the inventive magnetic core that in each case a first transverse connecting leg comprises first and second

Winding leg, a second cross-connecting leg second and third winding leg, and a third cross-connection legs connect the third and first winding legs together. Preferably, each cross-connection leg is connected to two winding legs. The individual cross-connection legs may only with two winding legs and, if necessary. Two transverse connecting legs be connected.

The magnetic core has a generally magnetically conductive properties. Insofar as the magnetic core is a passive component. The magnetic core forms no active magnet.

The magnetic core may form a plurality of magnetic circuits. The magnetic flux within the magnetic core is generated by induction. Specifically, the first and the second winding legs may partially form a first magnetic circuit. A second magnetic circuit may the second and third winding leg, and a third magnetic circuit may comprise the third and first winding leg. In all magnetic circuits a magnetic field can be performed, wherein the magnetic circuits in the

Have a substantially uniform flow length. Further, it is preferably provided that the magnetic circuits form the same magnetic resistance. This can be achieved by a single geometric structure and by the use of a single material of the magnetic core.

Concretely, it can be provided in the invention that the yoke, in particular the connecting limb forming a closed mold element. The closed mold member can have one, preferably centrally arranged, through-opening. Since the center of the yoke substantially no magnetically conductive material is needed to produce an adequate magnetic flux within a choke or a transformer is saved by the through hole material, which leads to a cost reduction. Further supports the

Through opening in a weight reduction of the magnetic core. Finally, the through opening so that overheating of a choke or of a transformer is avoided is also used for ventilation of the magnetic core or an inductor or a transformer.

The yoke may be generally formed in one piece or in several parts. The

integral production of the yoke promotes the homogeneity of the yoke or

total of the magnetic core. The multi-part design of the yoke can lead to cost saving, since standardized magnetic core components can be used. These are merely assemble and glue, for example.

the winding legs can each be formed in one or more parts also. Good results provide particular multi-part construction of the winding legs and / or the yoke. A plurality of air gaps between the individual elements of the yoke or the coil legs may also be provided. This "multi-gap" construction reduces the inductive losses and thus improves the magnetic flux within the magnetic core.

In particular, the yoke and / or the winding legs can be constituted by a pressed powder composite material. With help of a

Powder composite material which is pressed into the desired shape, a one-piece version of the yoke can be easily produced in particular. Alternatively, the powder composite material can also used for making

Individual components are used.

The powder composite material preferably comprises iron, nickel, silicon,

Aluminum and / or molybdenum. In concrete terms, it can be provided that the

, Forms powder composite material which is used to form the magnetic core is an alloy of nickel, iron and molybdenum or an alloy of iron and nickel, or an alloy of iron, silicon and aluminum or iron silicon alloy or another iron alloy. It is also possible to use for the magnetic core a ferrite material, an amorphous material and / or a nanocrystalline material.

The above-mentioned materials or material compositions have been shown to be particularly suitable for the production of a magnetic core. In particular, the magnetic properties of the magnetic core can be improved by the use of these materials.

In a particularly preferred embodiment of the invention, the yoke is formed triangular or hexagon-shaped. The triangular shape provides high compactness, since it merely connects the longitudinal ends of the winding legs together. In the hexagon-shaped embodiment of the yoke sharp edges are avoided, and the stackability of the magnetic core is promoted. Further, the hexagon shaped yoke covers a greater proportion of the windings of the coil legs in the longitudinal axial direction of the magnetic core. The

Hexagon shape of the yoke, thus contributing to the protection of the windings of a choke or of a transformer.

In a further preferred variant of the invention, the

Winding leg a circular or a rectangular cross-sectional shape. In other words, the winding legs may be a circular cylinder or cuboid-shaped. The circular cylindrical design of the

is winding legs because of the comparatively lower cost materials and tools effort. The use of a rectangular cross-section for the winding legs on the other hand improves the thermal properties of a choke or of a transformer. For the wrapping of the

Rectangular cross-section winding leg requires an increase in the distance between two turns or windings around the winding leg. This is in turn against the cooling of the windings as the windings can be as good flows through air.

The yoke may be glued to the winding limbs, especially the longitudinal ends of the winding legs. For bonding preferably, an adhesive is used which is resistant to high temperatures. The adhesive has a cushioning property, the vibration between the yoke and the

Winding leg cushion. The bonding itself is easy to

accomplish, thus facilitating the assembly of the magnetic core. This applies in particular to magnetic cores, which are constructed of magnetic sheet metal layers.

In a further preferred embodiment of the invention, a Ableitschenkel is arranged centrally between the three winding arms, which is connected to the yoke. The Ableitschenkel preferably extends parallel to the three winding legs. The Ableitschenkel for example, can cause high-frequency alternating magnetic fields and derive so unbalanced components or process.

Is an ancillary aspect of the invention relates to a three-phase choke or a three-phase transformer having a magnetic core as described above. The three-phase choke or the three-phase transformer also have at least one electrical winding, which is the one

Winding arm winds. Preferably, three electrical windings are provided, wherein in each case an electrical winding is associated with a winding leg of the magnetic core. Each electrical winding

preferably a phase of the three-phase alternating current assigned.

In a preferred embodiment of the choke according to the invention or of the transformer according to the invention, can be provided that the winding is formed by a flat wire, in particular a flat copper wire. The use of a flat wire is particularly suitable for low frequencies of the alternating current. In addition, the flat wire is characterized by a high mechanical stability. Finally, the use of a flat-wire leads to an overall compact structure of the reactor or of the

Transformer. In particular in the longitudinal axial length of the choke or the transformer, a reduction of the size can be achieved.

Instead of a flat wire, a round wire can be provided. In addition, as a material for the copper foil windings may be provided to use (Cu foil), H F strand or a combination of flat wire or round wire.

For example, an H F-strand can be combined with a flat wire.

The invention is explained in more detail below using an exemplary embodiment with reference to the accompanying diagrammatic drawings. in which:

FIG. 1 is a side view of a choke according to the invention or of a transformer according to the invention according to a preferred embodiment;

Fig. 2 is a plan view of the choke or transformer according to FIG. 1; and

Fig. 3 is a plan view of an alternative throttle or an alternative transformer according to a preferred embodiment. In Fig. 1 is a three-phase reactor or a three-phase AC choke is shown in a side view. The inductor comprises a magnetic core 10 with three winding legs 11, 12, 13. The three winding legs 11, 12, 13 are arranged in parallel or substantially extend parallel to a longitudinal axis of the throttle. At their longitudinal ends 18 are the

Winding legs 11, 12, 13 each connected to a yoke fourteenth The yoke 14 couples the three winding legs 11, 12, 13 magnetically to each other. Here, the yoke 14 with the winding legs 11, 12 be glued,. 13

In general, the winding leg 11, 12, 13 and the yoke 14 may be made from a powder composite material. The overall magnetic core is formed so far as a powder core. The use of a dust core material has the advantage that 10 micro air gaps form in the manufacture of the magnetic core within the magnetic core 10, which are advantageous for the magnetic permeability. Generally, it is advantageous for a uniform magnetic flux or uniform magnetic resistance, when the yoke 14 and the winding leg 11, 12, 13 are formed of the same material.

In an embodiment not shown here it may be provided that a fourth coil leg as Ableitschenkel centrally between the three

is winding legs 11, 12 arranged. 13 The fourth winding leg may have a ferrite core and be capable of leading a magnetic field that can adjust for asymmetries in the three-phase system.

In particular, the fourth Ableitschenkel may be less than the three

its winding legs 11, 12, 13 formed and asymmetrical

lead harmonics. In the fourth Ableitschenkel thereby high-frequency alternating magnetic fields set, resulting in an overall

Improving the symmetry of a three phase choke leads. The same applies to a three-phase transformer, which only differs from the three-phase choke that additional windings on the winding legs 11, 12, 13 are applied.

As shown in Fig. 1 will also be appreciated have the yoke 14 and the

Winding legs 11, 12, 13 have substantially the same thickness. An improvement of the magnetic flux is also achieved while reducing the cost of materials. The three winding legs 11, 12, 13 comprise a first winding leg 11, a second winding leg 12, and a third winding leg 13. The first winding leg 11 carries a first winding 21. The second

Winding leg 12 carries a second winding 22. The third

Winding leg 13 supports a third winding 23. The windings 21, 22, 23 may be identically formed. Preferably, the windings 21, 22, 23 formed by a copper wire, in particular a copper wire, are.

It is particularly advantageous, a flat wire or a flattened

to use copper wire. Thus, the size of the reactor can be reduced as a whole on an enlarged conductor cross-section and correspondingly high currents, which can thereby be performed. Specifically, the height of the windings 21, 22, 23 can be reduced in this manner, while still providing high currents can be passed.

The individual windings 21, 22, 23 each have two coil terminals 20, which serve for electrical connection of the windings 21, 22, 23rd Preferred is when each of the windings 21, 22, 23 different phases of a three-phase system is associated. Thus, the first winding 21 of a first electrical phase LI, the second winding 22 of a second electrical phase L2 and the third coil 23 may be associated with a third electrical phase L3.

In Figures 2 and 3 show two different embodiments of a throttle are shown, which differ from each other by the geometrical shape of the yoke fourteenth The side view of FIG. 1 is true for both

Embodiments according to figures 2 and 3. FIG.

In Fig. 2 it can be seen that the yoke 14 is annular. Of the

Magnetic core 10 so far comprises an annular yoke 14. The annular yoke 14 has a through opening 19 which is circular. The width of the annular yoke 14 corresponds substantially to the diameter of the winding legs 11,12, 13. The yoke 14 thus is fully supported on the winding legs 11, 12, 13, and in particular its longitudinal ends 18, on.

Specifically, the yoke 14 includes three transverse connecting leg 15, 16, 17, which are respectively formed a circular arc. A first transverse connecting leg 15 connects thereby the first and second winding leg 11, 12 to each other. A second cross-connecting leg 16 connects the second winding leg 12 with the third winding leg 13. The third winding leg 13 and the first winding legs 11 are connected by a third

Transverse connecting leg 17 of the yoke 14 magnetically connected.

As also can be clearly seen in Fig. 2, the yoke 14 and the end faces of the windings 21, 22,23 comparatively large overlapping areas have.

Insofar 14 covers the yoke of a relatively large proportion of the windings 21, 22, 23, and has in the longitudinal axial direction of a protection against damage. In addition, the yoke 14 extends up to the outer edge of the throttle as a whole and thus serves also in the radial direction relative to a central longitudinal axis of the throttle as a stop.

In Fig. 3, an alternative design of the yoke 14 is shown, wherein the yoke forms a polygon shape. Concretely, the throttle 3, the illustrated Fig. Is provided with a

triangular yoke 14 is provided, which has a triangular through hole 19th The triangular yoke 14 also has three transverse connecting leg

15, 16, 17, respectively connecting the first, second and third winding leg 11, 12, 13 with each other. The cross-connecting leg 15 run,

16, 17 in a straight line between two adjacent coil legs 11, 12,. 13 A junction or coupling of the transverse connecting leg 15, 16, 17 is in each case at the longitudinal ends 18 of the winding leg 11, 12,. 13

Also in Fig. 3 it can be seen that the triangular configuration of the yoke 14 to a relatively large overlap of yoke surface and end surface of the

Windings 21, 22, 23 performs. In that regard, even the yoke 14 according to Fig. 3 increased protection against damage to the windings 21, 22, 23. The transverse connecting leg 15, 16, 17 preferably have a width that the

Diameter of the winding leg 11, 12, 13 corresponds. This enables a good magnetic flux and further reduces the cost of materials for the magnetic core 10th

In Figures 2 and 3, the winding leg 11, 12, 13 are each as

Around the core legs formed. However, it is also possible that

Winding legs 11, 12, equipped with a rectangular cross-sectional geometry. 13 The width of the yoke 14, in particular the transverse connecting leg 15, 16, 17 is then adjusted accordingly. As in the two embodiments can be seen in accordance with Figures 2 and 3, the ring-shaped or convex polygon-shaped yoke 14 provides an improved footprint for the reactor. In particular, the chosen geometry facilitates stacking a plurality of magnetic cores 10 or from reactors or transformers which are equipped with the magnetic core 10 degrees. It is also apparent that builds compact as a whole by the triangular arrangement of the winding leg 11, 12, 13, the throttle. At the same time, by appropriate

Abstandsmaßgaben between the individual winding legs 11, 12, 13 an improved cooling of a reactor or a transformer can be achieved. Also contributes to the through-hole 19 in the yoke 14th A further contribution to cooling of the choke or the transformer does the nature of the winding 21, 22, 23. Preferably, the windings 21, 22, 23 are formed by a flat wire, which is also improved with the appropriate winding pitch cooling. The choke or the transformer is thus a total of

powerful.

The triangular-shaped yoke 14 preferably forms an isosceles, more preferably an equilateral triangle. This makes a particularly compact

Construction possible. Moreover, the stackability of the magnetic core 10 is improved. In the equilateral triangular design of the yoke 14 have the transverse connecting leg 15, 16, 17 to one another in each case an angle of 60 °.

LIST OF REFERENCE NUMBERS

10 magnetic core

11, first winding leg

12, second winding leg

13, third winding leg

14 yoke

15 first cross-connecting leg

16 second transverse connecting leg

17 third cross-connecting leg

18 longitudinal end

19 through opening

20 Winding connection

21 first winding second winding third winding