EP2495742A1 - High-voltage resistant electricity-compensated interference suppression choke - Google Patents

Abstract

The inductor (3) has closed core (4) which are wound with coils (5,6). The coils with commutative electric conductors (a,b) form a filter circuit. The coils are wound over the same portion (7) of the periphery of the core.

Description

The invention relates to a high-current resistant, current-compensated radio interference suppression choke with a self-contained core of a soft magnetic material, with at least two wound around the core coils and with the coils forming, guided in a filter circuit electrical conductors.

Such high-current, current-compensated radio interference suppression chokes are required at currents starting at one hundred amps and are known in practice, for example in diesel hybrid drives. The self-contained core can be designed annular and, if necessary, have an air gap.

From practice a high-current radio interference suppression choke has become known, in which the core is divided into two separate sections. On each of the sections a single coil is arranged. The coils thus extend over less than half the circumference of the core. A disadvantage of the known radio interference suppression choke, however, is that the structure of the suppression choke requires sufficient space for sufficient damping. The described arrangement of the coils is asymmetrical and leads to a magnetic saturation of the core, especially at high currents. An enlargement of the core leads to a high space requirement and thus to high material costs.

The invention is based on the problem of further developing a radio interference suppression choke of the type mentioned at the beginning in such a way that it has a high damping and a particularly small footprint even at high current intensities.

This problem is inventively solved in that the coils are wound over the same portion of the circumference of the core.

As a result of this design, the circumference of the core for the arrangement of the coils can be largely utilized at first. Thus, the core can have particularly small dimensions. The small dimensions lead to low production costs. The windings of the coils can be arranged uniformly distributed over the entire circumference of the core. The symmetry of the windings avoids partial saturation of the core at high currents. Thanks to the invention, a high impedance can be achieved via the frequency in DC applications, and thus an attenuation in the so-called common mode.

The RFI choke invention is particularly compact, when the portion of the core over which both coils are wound, more than half of the total circumference of the core corresponds. This design also leads to particularly low production costs of Funkfeststördrossel invention.

A particularly even distribution of the turns of the coils of the RFI choke according to the invention can be achieved easily if the portion of the core, over which both coils are wound, corresponds to almost the total length of the core. As a result of this design, the circumference of the core is used as far as possible to accommodate the coils.

The radio interference suppression choke invention is particularly simple in construction, when the electrical conductors of different coils are wound in parallel. With this design, the two electrical conductors before the winding can be structurally combined and wrap around the core. This also leads to a further reduction of the manufacturing costs of the radio interference suppression choke according to the invention.

Accurate positioning of the electrical conductors of different coils to each other can be easily ensured according to another advantageous embodiment of the invention, when the electrical conductors of different coils are twisted together and when the twisted conductors are wound around the core.

A particularly compact construction of the radio interference suppression choke according to the invention can be achieved simply if the electrical conductors are wound in different positions around the core. As a result of this configuration, a multiple of the turns of the conductors can be arranged on the core in comparison to a single-layer winding, depending on the number of layers.

Provided damping characteristics of Funkfeststrossrossel invention can be easily adjusted when the coils are composed of several, parallel or series-connected partial coils. The interconnection of the partial coils allows many possibilities. For example, the conductors of different partial coils can be wound on different layers. Alternatively, the conductors of partial coils of different coils can be wound in parallel on one layer and the other partial coils of the different coils on a different layer.

Heat is often generated during operation of the radio interference suppression choke, which must be dissipated. You could cool the radio interference suppression choke in a stream of air. A particularly high cooling capacity can be achieved according to another advantageous embodiment of the invention, when the electrical conductors are formed as a waveguide. By this design, a cooling medium, such as cooling water or air, can promote through the waveguide and thus carry away the heat.

The electrical conductors are reliably held in their position according to another advantageous embodiment of the invention, when the electrical conductors are solid. By this design, the electrical conductors have a high intrinsic stability.

The electrical conductors are particularly flexible according to another advantageous embodiment of the invention, when the electrical conductors are designed multi-core.

Fig. 1

eine erfindungsgemäße, in einer Filterschaltung montierte Funkentstördrossel,

Fig. 2a

zwei elektrische Leiter der Funkentstördrossel aus Figur 1,

Fig. 2b

einen Abschnitt eines Kerns der Funkentstördrossel aus Figur 1, um den die elektrischen Leiter gewickelt sind, in gestreckter Darstellung,

Fig. 3

zwei verdrillte elektrische Leiter für die Funkentstördrossel,

Fig. 4

eine weitere Ausführungsform der Funkentstördrossel,

Fig. 5

einen Abschnitt eines Kerns der Funkentstördrossel aus Figur 4, um den elektrische Leiter gewickelt sind, in gestreckter Darstellung,

Fig. 6

einen Abschnitt eines Kerns einer Funkentstördrossel mit einer Verschaltung mehrerer Lagen von elektrischen Leitern,

Fig. 7

eine gegenüber der Anordnung nach Figur 6 alternative Verschaltung mehrerer Lagen von elektrischen Leitern,

Fig. 8

eine graphische Darstellung des Verlaufs der Nenninduktivität über die Stromstärke der erfindungsgemäßen Funkentstördrossel gegenüber einem Stand der Technik,

Fig. 9

eine graphische Darstellung des Verlaufs der Streuinduktivität über die Stromstärke der erfindungsgemäßen Funkentstördrossel gegenüber einem Stand der Technik.

The invention allows numerous embodiments. To further clarify its basic principle, one of them is shown in the drawing and will be described below. This shows in

Fig. 1

a radio interference choke according to the invention, mounted in a filter circuit,

Fig. 2a

two electrical conductors of the radio interference suppression choke off FIG. 1 .

Fig. 2b

a section of a core of the radio interference choke off FIG. 1 around which the electrical conductors are wound, in stretched form,

Fig. 3

two twisted electrical conductors for the radio interference choke,

Fig. 4

a further embodiment of the radio interference choke,

Fig. 5

a section of a core of the radio interference choke off FIG. 4 to the electrical conductor are wound, in stretched form,

Fig. 6

a section of a core of a radio interference choke with an interconnection of several layers of electrical conductors,

Fig. 7

one opposite the arrangement according to FIG. 6 alternative interconnection of several layers of electrical conductors,

Fig. 8

4 is a graphical representation of the course of the nominal inductance over the current intensity of the radio interference suppression choke according to the invention compared with a prior art;

Fig. 9

a graphical representation of the course of the leakage inductance on the current strength of the RFI choke according to the invention over a prior art.

FIG. 1 shows a switched between a Störsenke 1 and a source of interference 2 high-current, current-compensated Funkeststsstrossel 3. The radio interference suppression choke 3 has an annular core 4 to which two electrical conductors a, b of two coils 5, 6 are wound. The electrical conductors a, b lead from the interference sink 1 to the interference source 2. A section 7, around which the conductors a, b are wound, corresponds to almost the entire length of the core 4.

The core 4 is shown in the illustrated embodiment without an air gap. Of course, the core 4 may also have an air gap. Furthermore, the core 4 can also be designed differently from the illustrated annular design rectangular or the like.

FIG. 2a shows the electrical conductors a, b, the radio interference suppression choke 3 off FIG. 1 , It can be seen that these are guided parallel next to each other. FIG. 2b illustrates in a plan view of a stretched representation of the portion 7, around which the conductors are wound a, b, the parallel winding of the conductors a, b.

FIG. 3 shows an alternative arrangement of electrical conductors a, b for winding the coils 5, 6 of the radio interference suppression choke 3 FIG. 1 , It can be seen here that the conductors a, b are twisted. These twisted conductors a, b can be wrapped around the core 4 of the radio interference suppression choke 3 FIG. 1 wrap.

FIG. 4 shows a high-current resistant, current-compensated radio interference suppression choke 8 with arranged on different layers electrical conductors a, b. The conductors a, b are different for different coils 9, 10 Layers and thus wound around a core 11 at different distances. The conductors a, b are as in the embodiment of FIG. 1 over a over almost the entire length of the core extending portion 12 is wound. The spacing of the layers is identified by the reference numeral 13.

FIG. 5 shows the core 11 of the radio interference suppression choke 8 FIG. 4 in an extended view of section 12 over which electrical conductors a, b are wound. It can be seen here that the conductor a of the first coil 9 is wound directly onto the core 11 and the conductor b of the second coil 10 is wound around the first coil 9. Thus, the diameter of the conductor a of the first coil 9 in conjunction with an insulation, not shown, of the conductor a, b determines the distance 13 of the layers of the coils 9, 10th

FIG. 6 shows a multi-layer interconnection of several, parallel-connected partial coils 14-17 of coils 18, 19 in a stretched representation of a portion of a core 20 of another embodiment of a radio interference choke 21. The individual conductors a - d of the partial coils 14-17 are each on one layer wrapped the core 20. To illustrate the winding, the individual conductors are marked on each turn of the coils.

FIG. 7 shows a further embodiment of a radio interference suppression choke 22 with a multi-layer interconnection of a plurality of parallel-connected sub-coils 23-26 of coils 27, 28 in a stretched representation of a portion of a core 29. In contrast to the embodiment according to FIG FIG. 6 are the individual conductors a - d wound over different layers relative to the core 29 and interconnected.

FIG. 8 shows the course of the nominal inductance on the current strength of the radio interference suppression chokes 3, 8, 21, 22 from the FIGS. 1 to 7 to a prior art RF choke in which the core is divided into two sections and a single coil is disposed on each of the sections. Furthermore, in FIG. 9 the course of the leakage inductance on the current strength of the radio interference suppression choke 3, 8, 21, 22 from the FIGS. 1 to 7 compared with a prior art shown.

The curves of the radio interference suppression choke 3, 8, 21, 22 from the FIGS. 1 to 7 are in the FIGS. 8 and 9 with LnUmf and the course of the nominal inductance of the suppression choke according to the prior art is marked with LnSek. In FIG. 8 It can be seen that the nominal inductance in the prior art RFI choke drops abruptly at a current above 400 amperes.

In general, B-fields induced in a current-compensated RFI choke are compensated for in the core. A large part of the corresponding H field of the windings enters into the polarization of the core material. A small part of the H-field closes over the stray portion of the magnetic circuit. In connection with the asymmetrical winding structure in the radio interference suppression choke according to the prior art, the core material is polarized asymmetrically. At low currents or large-volume cores, the asymmetries are not important. However, these asymmetries lead to partially very different polarizations of the core material and thus to local saturations of the core material. This effect becomes more pronounced the higher permeable the core material used. The geometry of the magnetic Circle is not decisive, but the way of coupling the H-field of the winding into the core material. Particularly at high currents above 100 amperes, the asymmetries lead to partial saturation of the core and thus to the fact that the attenuation of the current-compensated RFI choke is impaired. This effect also occurs more strongly the higher the permeability of the magnetic circuit. However, especially with current-compensated RF suppression chokes, highly permeable materials are used in order to achieve the required impedance with low numbers of turns and thus with low copper losses.

The in the FIGS. 1 to 7 described winding structure of the radio interference suppression chokes 3, 8, 21, 22 is characterized in that the windings are evenly and thus scattered low over the circumference of the core 4, 11, 20, 29 distributed. The more the windings remain symmetrical, the more the partial saturation of the core 4, 11, 20, 29 at high currents can be avoided. In this case, the insulation requirements of the electrical conductors a - d in the winding structure are to be observed.

The principles of the invention are explained in more detail below. The effect of the high-current-compensated RFI suppression choke (HSKD) is based on the high sensitivity (inductance L _h ) of the soft-magnetic circuit to small differential currents Δi. The maximum size of the still to be damped differential currents .DELTA.i _gr is determined by $$\mathrm{\Delta }{i}_{\mathit{gr}}=\frac{B_{\mathit{sätt}}*l_{\mathit{Fri.}}}{{\mathrm{<figure-callout\; id="0"\; label="\mu "\; filenames="imgf0004.png"\; state="\{\{state\}\}">\mu </figure-callout>}}_0{\mu }_r*w}\mathrm{and}{L}_H={\mathrm{<figure-callout\; id="0"\; label="\mu "\; filenames="imgf0004.png"\; state="\{\{state\}\}">\mu </figure-callout>}}_0{\mu }_r*{\mathrm{<figure-callout\; id="2"\; label="w"\; filenames="imgf0001.png,imgf0004.png"\; state="\{\{state\}\}">w</figure-callout>}}^2*\frac{A_k}{l_{\mathit{Fe}}}$$

$$I_{\mathit{zul}}=\frac{{\mathit{B}}_{\mathit{sätt}}=A_k*w}{L_{\sigma }}$$

For high-current applications I _v ≥ 100 A), the core of the SKD is driven into saturation by the leakage flux L _σ and thus limits the current level I _zul . $$L_{\sigma }={\mathrm{<figure-callout\; id="2"\; label="w"\; filenames="imgf0001.png,imgf0004.png"\; state="\{\{state\}\}">w</figure-callout>}}^2*{\mathrm{G}}_{\sigma }{\mathrm{G}}_{\sigma }=\frac{{\phi }_{\mathit{\sigma gr}}}{I_{\mathit{zul}}*w}{\mathrm{B}}_{\mathrm{sätt}}=\frac{{\phi }_{\mathit{\sigma gr}}}{A_k}$$

$$I_{\mathit{zul}}=\frac{{\mathit{B}}_{\mathit{sätt}}=A_k*w}{L_{\sigma }}$$

A reduction in the winding _{leakage inductance} increases the permissible limit current I _zul . $$\frac{I_{\mathit{zul}}}{\mathrm{\Delta }{i}_{\mathit{gr}}}=\frac{L_H}{L_{\sigma }}$$

A high damping of the differential currents with simultaneously high permissible currents can only be achieved by a small winding leakage inductance.

Claims (10)

High current resistant, current-compensated radio interference suppression choke (3, 8, 21, 22) with at least two coils (5, 6, 9, 10, 18, 19, 27, 28) wound around a closed core (4, 11, 20, 29) and with the coils (5, 6, 9, 10, 18, 19, 27, 28) forming, in a filter circuit guided electrical conductors (a - d), characterized in that the coils (5, 6, 9, 10, 18, 19, 27, 28) are wound over the same portion (7, 12) of the circumference of the core (4, 11, 20, 29). Radio interference suppression choke according to Claim 1, characterized in that the section (7, 12) of the core (4, 11, 20, 29), over which both coils (5, 6, 9, 10, 18, 19, 27, 28) wound are more than half of the total circumference of the core (4, 11, 20, 29). Radio interference suppression choke according to Claim 1 or 2, characterized in that the section (7, 12) of the core (4, 11, 20, 29) over which both coils (5, 6, 9, 10, 18, 19, 27, 28 ), nearly equal to the total length of the core (4, 11, 20, 29). Radio suppression choke according to one of claims 1 - 3, characterized in that the electrical conductors (a - d) of different coils (5, 6, 18, 19, 27, 28) are wound in parallel. Radio interference suppression choke according to one of claims 1 to 3, characterized in that the electrical conductors (a, b) of different coils (9, 10) are twisted together and that the twisted conductors (a, b) are wound around the core (4). Radio interference suppression choke according to one of claims 1 to 5, characterized in that the electrical conductors (a-d) are wound in different positions around the core (20, 29). Radio interference suppression choke according to one of Claims 1 to 6, characterized in that the coils (18, 19, 27, 28) are composed of a plurality of partial coils (14-17, 23-26) connected in parallel or in series. Radio suppression choke according to one of claims 1 - 7, characterized in that the electrical conductors (a - d) are formed as waveguides. Radio interference suppression choke according to one of Claims 1 to 8, characterized in that the electrical conductors (a-d) are solid. Radio interference suppression choke according to one of Claims 1 to 9, characterized in that the electrical conductors (a-d) are of multi-core design.

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