INDUCTOR FOR HIGH FREQUENCY AND HIGH POWER APPLICATIONS

Abstract

The present invention relates to an inductor (10) for high frequency and high power applications. The inductor (10) comprises at least one wire conductor (20), and a coil zone (30). Windings of the at least one wire conductor comprises the at least one wire conductor being wound around the coil zone to form a substantially torus shape centred around an axis extending in an axial direction of the torus shape. At an outer extent of the coil zone, outer windings of the at least one wire conductor are substantially at a first radial distance from the axis. At an inner extent of the coil zone, inner windings of the at least one wire conductor are substantially at a second radial distance from the axis and substantially at a third radial distance from the axis respectively. When an inner winding of the at least one conductor is at the second radial distance the next inner winding of the at least one conductor is at the third radial distance.

Claims

1. An inductor for high frequency and high power applications in X-ray generation, comprising: at least one wire conductor forming a plurality of windings that include inner windings and outer windings; a coil zone; wherein the windings are wound around the coil zone to form substantially a torus centered around an axis extending in an axial direction of the torus; wherein at an outer side of the coil zone the outer windings are substantially at a first radial distance from the axis; wherein at an inner side of the coil zone the inner windings are substantially at a second radial distance from the axis and substantially at a third radial distance from the axis, such that when one inner winding is at the second radial distance an adjacent inner winding is at the third radial distance; wherein the coil zone comprises an air gap, and wherein at least one winding is taken through the air gap.

2. The inductor according to claim 1, wherein at the inner side of the coil zone the windings are formed as pairs of windings, wherein a radial line from the axis that extends through a first winding of a pair of windings substantially extends through a second winding of the pair of windings.

3. The inductor according to claim 1, wherein the first radial distance is substantially twice an average of the second and third radial distances.

4. The inductor according to claim 1, wherein a structure, positioned within the air gap, has at least one support that is configured such that the at least one winding that is taken through the air gap is supported by the at least one support.

5. The inductor according to claim 1, wherein the at least one conductor comprises a first wire and a second wire, and wherein the windings are formed from the first wire and the second wire.

6. The inductor according to claim 5, wherein the windings are formed as pairs of windings, and wherein a first pair of windings comprises the first wire at the second radial distance and the second wire at the third radial distance, and a second pair of windings adjacent to the first pair of windings comprises the first wire at the third radial distance and the second wire at the second radial distance.

7. The inductor according to claim 5, wherein the winding of the first wire is taken through the air gap, and the winding of the second wire is taken through the air gap.

8. The inductor according to claim 1, wherein connection terminals for the at least one conductor are positioned adjacent to one another.

9. The inductor according to claim 1, wherein the at least one conductor comprises Litz wire.

10. The inductor according to claim 1, wherein the inductor is arranged in a high power generator for use in X-ray generation.

11. An apparatus for generating X-rays, comprising: an X-ray source; and a power supply comprising a high power generator that includes an inductor for high frequency and high power applications in X-ray generation, the inductor comprising: at least one wire conductor forming a plurality of windings that include inner windings and outer windings; a coil zone; wherein the windings are wound around the coil zone to form substantially a torus centered around an axis extending in an axial direction of the torus; wherein at an outer side of the coil zone the outer windings are substantially at a first radial distance from the axis; wherein at an inner side of the coil zone the inner windings are substantially at a second radial distance from the axis and substantially at a third radial distance from the axis, such that when one inner winding is at the second radial distance an adjacent inner winding is at the third radial distance; wherein the coil zone comprises an air gap, and wherein at least one winding is taken through the air gap.

12-14. (canceled)

15. A method for generating X-rays, comprising: providing an X-ray source; and providing a power supply comprising a high power generator that includes an inductor for high frequency and high power applications in X-ray generation, the inductor comprising: at least one wire conductor forming a plurality of windings that include inner windings and outer windings; a coil zone; wherein the windings are wound around the coil zone to form substantially a torus centered around an axis extending in an axial direction of the torus; wherein at an outer side of the coil zone the outer windings are substantially at a first radial distance from the axis; wherein at an inner side of the coil zone the inner windings are substantially at a second radial distance from the axis and substantially at a third radial distance from the axis, such that when one inner winding is at the second radial distance an adjacent inner winding is at the third radial distance; wherein the coil zone comprises an air gap, and wherein at least one winding is taken through the air gap.

16. A non-transitory computer-readable medium having one or more executable instructions, which, when executed by a processor, cause the processor to perform a method for generating X-rays, the method comprising: providing an X-ray source; and providing a power supply comprising a high power generator that includes an inductor for high frequency and high power applications in X-ray generation, the inductor comprising: at least one wire conductor forming a plurality of windings that include inner windings and outer windings; a coil zone; wherein the windings are wound around the coil zone to form substantially a torus centered around an axis extending in an axial direction of the torus; wherein at an outer side of the coil zone the outer windings are substantially at a first radial distance from the axis; wherein at an inner side of the coil zone the inner windings are substantially at a second radial distance from the axis and substantially at a third radial distance from the axis, such that when one inner winding is at the second radial distance an adjacent inner winding is at the third radial distance; wherein the coil zone comprises an air gap, and wherein at least one winding is taken through the air gap.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Exemplary embodiments will be described in the following with reference to the following drawings:

[0060] FIG. 1 shows a schematic example of an inductor in the left hand drawing where 2 wires are in parallel, twisted for 180 per winding, and a cut through section of the inductor in the right hand drawings;

[0061] FIG. 2 shows a schematic example of a first winding of an inductor;

[0062] FIG. 3 shows a schematic example of a winding of an inductor;

[0063] FIG. 4 shows a schematic example of a coil former in dissembled form in the top drawing and in assembled form in the bottom drawing;

[0064] FIG. 5 shows a schematic example of an apparatus for generating X-rays; and

[0065] FIG. 6 shows an example of a method for generating X-rays.

DETAILED DESCRIPTION OF EMBODIMENTS

[0066] FIG. 1 shows a schematic example of an inductor 10 in the left hand drawing and a cut through section of the inductor shown in the right hand drawing. A compensation winding 50, that can be formed from windings 52 and 54 of a first wire conductor 22 and a second wire conductor 24 of at least one wire conductor 20, is shown within an air gap. However, the double, and indeed triple, winding scheme described here can be used around cores other than air cores, such as magnetic cores, in which case a compensation winding 50 may not be used. Therefore, the windings can be considered to be around a coil zone 30, rather than necessarily around an air gap. Also, rather than using at least one wire conductor 20 in the form of two wires 22 and 24 (or indeed three wires), a single wire can be used to form the double winding described below. Also, it is to be noted that the inductor shown in FIG. 1 is represented schematically, such that the compensation winding 50 is not shown as being formed from the windings around the corethis is presented in FIG. 1 for simplicitly of representation. FIG. 2 shows how one wire 22 of the at least one wire conductor can be wound around an air core, with a winding 52 being taken back through the air core. In FIG. 2, again for simplicity the second wire conductor 24 is not shown, however as shown in FIG. 1 it would also be wound around the air core such that two windings would be on top of each other on the inner side of the core, but adjacent to one another on the outer side of the core. Also, rather than having two wires, the single wire 22 could be wound in a double winding configuration.

[0067] Referring to FIG. 1 in more detail, an inductor 10 for high frequency and high power applications is shown. The inductor 10 comprises at least one wire conductor 20, and a coil zone 30. Windings of the at least one wire conductor 20 comprises the at least one wire conductor 20 being wound around the coil zone 30 to form a substantially torus shape centred around an axis extending in an axial direction of the torus shape. Thus the axis extends down through the centre of the windings shown in FIG. 1, and referring to FIG. 3 the axis extends out of the page at the position from which radii r, a, and b extend. With continued reference to FIG. 1 at an outer extent of the coil zone 30, outer windings of the at least one wire conductor 20 are substantially at a first radial distance from the axis. At an inner extent of the coil zone 30, inner windings of the at least one wire conductor 20 are substantially at a second radial distance from the axis and substantially at a third radial distance from the axis respectively. When an inner winding of the at least one conductor 20 is at the second radial distance the next inner winding of the at least one conductor is at the third radial distance. Thus referring to FIG. 3, which shows a simplified inductor that for ease of visualization has not shown the above described double winding, the outer windings are at a first radius b, and inner windings rather than being the single windings shown in FIG. 3, are actually in the double windings shown in FIG. 1. Thus, the inner radius a, in the inductor 10 is actually two radii of windings.

[0068] In an example, the windings of the at least one wire at the first radial distance are exactly adjacent to one another, or in other words touching. In other words, the windings at the outer side of the core (or coil zone) are butted up against each other.

[0069] In an example, the windings of the at least one wire at the third radial distance are exactly adjacent to one another, or in other words touching. In other words, the windings at the inner side of the coil zone are butted up against each other.

[0070] In an example, at an inner extent of the coil zone, windings of the at least one wire conductor are substantially at the second radial distance from the axis and substantially at the third radial distance from the axis respectively, and substantially at a fourth radial distance from the axis. In other words, a triple winding scheme is used, where instead of using a single turn around a coil zone three turns are used. To put this another way, on the inner side of the toroid the three turns are on top of each other, whilst on the outer side of the toroid the turns are adjacent to one another.

[0071] In an example, the coil zone comprises an air gap.

[0072] By having an air core, rather than a magnetic core, at high power levels required for example for an X-ray generator, high losses at high frequencies are mitigated and the demands associated with thermal management are reduced. Inductors of any inductance value are then realisable, which are compatible with switching technologies based on wide band gap semiconductors such as SiC and GaN, which can operate at switching frequencies above 100 kHz and up to 1 MHz and at currents of several hundred Amps.

[0073] According to an example, at the inner extent of the coil zone 30, windings of the at least one wire conductor 20 are formed as pairs of windings 40. A radial line from the axis that extends through a first winding 40a of a pair of windings also substantially extends through a second winding 40a of the pair of windings.

[0074] In an example, at the inner extent of the coil zone, windings of the at least one wire conductor are formed as a triplet of windings. A radial line from the axis that extends through a first one of the triplet of windings also substantially extends through a second one of the triplet of windings, and also extends through a third one of the triplet of windings.

[0075] In an example, the outer radius is approximately N times the inner radius, where N is the number layers on windings on the inner radius. Thus inductors with N=2 and N=3 and higher numbers are possible.

[0076] According to an example, the first radial distance is substantially twice the average of the second and third radial distances.

[0077] In an example, the first radial distance is substantially three times the average of the second and third and fourth radial distances. Thus, again the wires on the inner side of the coil zone can be touching one another as can the wires on the outer side of the coil zone. According to an example, the coil zone 30 comprises an air gap, and windings of the at least one wire conductor 20 comprises at least one winding 50 of the at least one wire conductor being taken back through the air gap.

[0078] In an example, the return winding is placed coaxially with the coil geometry within the coil's centre plane.

[0079] In an example, the at least one winding of the at least one wire conductor being taken back through the air gap is at a radius from the axis such that resulting stray fields are minimized. The specific radius can be determined through simulation and/or manual adaptation.

[0080] According to an example, a former is positioned within the air gap 30. The former has at least one support. The at least one support is configured such that the at least one winding 50 of the at least one wire conductor 20 that is taken back through the air gap is supported by the at least one support. An example of a former is shown in FIG. 4.

[0081] In an example, a ring structure 60 is positioned within the air gap 30. The ring structure has at least one groove. The at least one groove is configured such that the at least one winding 50 of the at least one wire conductor 20 that is taken back through the air gap sits in the at least one groove. An example of a ring structure is shown in FIG. 4.

[0082] In this manner, the compensation winding(s) can be accurately positioned and maintained in position.

[0083] In an example, the ring structure is made from thermoplastic. According to an example, the at least one conductor 20 comprises a first wire conductor 22 and a second wire conductor 24. The windings are formed from the first wire conductor and the second wire conductor.

[0084] In an example, the at least one conductor comprises a first wire conductor and a second wire conductor and a third wire conductor. The windings are formed from the first wire conductor and the second wire conductor and the third wire conductor. In other words, instead of using a single wire with three turns, three wires are used to accomplish the double winding.

[0085] According to an example, windings of the at least one wire conductor 20 are formed as pairs of windings 40. A first pair of windings 42 comprises the first wire conductor 22 at the second radial distance and the second wire conductor 24 at the third radial distance. A pair of windings 44 adjacent to the first pair of windings comprises the first wire conductor 22 at the third radial distance and the second wire conductor 24 at the second radial distance.

[0086] According to an example, the coil zone comprises an air gap. A winding 52 of the first wire conductor 22 is taken back through the air gap 30, and a winding 54 of the second wire conductor 24 is taken back through the air gap.

[0087] In an example, a winding of a third wire conductor is taken back through the air core.

[0088] According to an example, connection terminals for the at least one conductor are positioned adjacent to one another.

[0089] In an example, the at least one conductor can be any normal type of wire, such as a copper wire.

[0090] In an example, the at least one conductor can be formed from a bundle of individual wires.

[0091] According to an example, the at least one conductor 20 comprises Litz wire.

[0092] In an example, the inductor is configured to operate at frequencies up to 100 kHz. In an example, the inductor is configured to operate at frequencies up to 1 MHz. In an example, the inductor is configured to operate at currents up to 100 Amps. In an example, the inductor is configured to operate at currents up to 1000 Amps at 150 kHz using only air cooling with natural convection.

[0093] FIG. 5 shows an apparatus 200 for generating X-rays. The apparatus 200 comprises a high power generator 100. The high power generator comprises an inductor 10 for high frequency and high power applications according as described with respect to FIGS. 1-3. The high power generator thus has applicability in high power systems such as X-ray generators, but also for example in automotive applications. When an air core is utilized, the core will not saturate even in high power applications. Because saturation issues do not exist the coil offers excellent linearity. With an air core there are no core losses. Also, since the air core has no losses and no saturation there is no temperature dependent drift of core properties. Thus, an inductor (e.g. having an air core), which has high frequency and high power and low noise applicability, can be used to effectively generate high power.

[0094] With continued reference to FIG. 5, the apparatus 200 for generating X-rays comprises an X-ray source 210, and a power supply 220, comprising a high power generator 100 as described above. The power supply 220 is configured to produce a voltage. The X-ray source 210 comprises a cathode 212 and an anode 214. The cathode 212 is positioned relative to the anode 214, and the cathode 212 and anode 214 are operable such that electrons emitted from the cathode 212 interact with the anode 214 with energies corresponding to the voltage. The electrons interact with the anode 214 to generate X-rays.

[0095] FIG. 6 shows a method 300 for generating X-rays in its basic steps. The method 300 comprises: [0096] in a producing step 310, also referred to as step a), producing with a power supply 220 a voltage, wherein production of the voltage comprises utilising a high power generator 100; [0097] in a positioning step 320, also referred to as step b), positioning a cathode 212 of an X-ray source 210 relative to an anode 214 of the X-ray source 210; [0098] in an emitting step 330, also referred to as step c), emitting electrons from the cathode 212; [0099] in an interacting step 340, also referred to as step d), interacting electrons emitted from the cathode 212 with the anode 214 with energies corresponding to the voltage; [0100] in a generating step 350, also referred to as step e), generating X-rays from the anode 214, wherein the electrons interact with the anode 214 to generate the X-rays.

[0101] In another exemplary embodiment, a computer program or computer program element is provided that is characterized by being configured to execute the method steps of the method according to one of the preceding embodiments, an appropriate system.

[0102] The computer program element might therefore be stored on a computer unit, which might also be part of an embodiment. This computing unit may be configured to perform or induce performing of the steps of the method described above. Moreover, it may be configured to operate the components of the above described apparatus. The computing unit can be configured to operate automatically and/or to execute the orders of a user. A computer program may be loaded into a working memory of a data processor. The data processor may thus be equipped to carry out the method according to one of the preceding embodiments.

[0103] This exemplary embodiment of the invention covers both, a computer program that right from the beginning uses the invention and computer program that by means of an update turns an existing program into a program that uses invention.

[0104] Further on, the computer program element might be able to provide all necessary steps to fulfill the procedure of an exemplary embodiment of the method as described above.

[0105] According to a further exemplary embodiment of the present invention, a computer readable medium, such as a CD-ROM, is presented wherein the computer readable medium has a computer program element stored on it which computer program element is described by the preceding section.

[0106] A computer program may be stored and/or distributed on a suitable medium, such as an optical storage medium or a solid state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the internet or other wired or wireless telecommunication systems.

[0107] However, the computer program may also be presented over a network like the World Wide Web and can be downloaded into the working memory of a data processor from such a network. According to a further exemplary embodiment of the present invention, a medium for making a computer program element available for downloading is provided, which computer program element is arranged to perform a method according to one of the previously described embodiments of the invention.

[0108] It has to be noted that embodiments of the invention are described with reference to different subject matters. In particular, some embodiments are described with reference to method type claims whereas other embodiments are described with reference to the device type claims. However, a person skilled in the art will gather from the above and the following description that, unless otherwise notified, in addition to any combination of features belonging to one type of subject matter also any combination between features relating to different subject matters is considered to be disclosed with this application. However, all features can be combined providing synergetic effects that are more than the simple summation of the features.

[0109] While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. The invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing a claimed invention, from a study of the drawings, the disclosure, and the dependent claims.

[0110] In the claims, the word comprising does not exclude other elements or steps, and the indefinite article a or an does not exclude a plurality. A single processor or other unit may fulfill the functions of several items re-cited in the claims. The mere fact that certain measures are re-cited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope