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Dokumentenidentifikation EP1519392 31.08.2006
EP-Veröffentlichungsnummer 0001519392
Titel Drosselspulenanordnung
Anmelder ABB Oy, Helsinki, FI
Erfinder Miettinen, Erkki, 00170 Helsinki, FI
Vertreter derzeit kein Vertreter bestellt
DE-Aktenzeichen 602004001559
Vertragsstaaten AT, BE, BG, CH, CY, CZ, DE, DK, EE, ES, FI, FR, GB, GR, HU, IE, IT, LI, LU, MC, NL, PL, PT, RO, SE, SI, SK, TR
Sprache des Dokument EN
EP-Anmeldetag 07.09.2004
EP-Aktenzeichen 041043019
EP-Offenlegungsdatum 30.03.2005
EP date of grant 19.07.2006
Veröffentlichungstag im Patentblatt 31.08.2006
IPC-Hauptklasse H01F 37/00(2006.01)A, F, I, 20051017, B, H, EP
IPC-Nebenklasse H01F 27/38(2006.01)A, L, I, 20051017, B, H, EP   

Beschreibung[en]
BACKGROUND OF THE INVENTION

The invention relates to inductor arrangements comprising an input inductor coupled to the input side of an electrical apparatus and an output inductor coupled to the output side of the apparatus.

Input and output inductors are used to reduce interference that an electrical apparatus causes to the input and output side networks. Input and output inductors are used for instance in frequency converter configurations. Examples of known inductor assemblies are described in publications US 2002/125854 A1, PATENT ABSTRACTS OF JAPAN vol. 1996, no. 02, 29 February 1996 (1996-02-29) -& JP 07 263262 A (SONY CORP), 13 October 1995 (1995-10-13), DE 19933811 A and EP-A-0012629.

In frequency converters, rectification is typically implemented by means of a six-pulse diode bridge, which is known to use line current only at the surroundings of the peak voltage of a sequence, thus causing extensive current pulses that stress the network. In order to reduce the amplitude of these current pulses it is known in the art to use series inductors, i.e. input inductors, placed in the feeding phases.

Power inversion and pulse-width modulation used to control the output voltage level of the fundamental wave cause extremely rapidly ascending and descending edges, a kind of surge waves, to the output voltage. These surge waves may create two types of problems in the motor to be fed: high turn voltages of the winding including the risk of discharge and bearing currents. In order to attenuate each of the mentioned phenomena it is known in the art to employ phase-specific series inductors, i.e. output inductors, to be placed at the beginning of a motor cable at the output side of the frequency converter that allow smoothing the voltage edges observable in the terminals of the motor.

An input inductor is generally a three-columned and two-windowed three-phase inductor assembled of columns and yokes composed of armature sheets and copper or aluminium windings. The magnetic path is provided with one or more air gaps that prevent the magnetic core from being saturated. Such a component intended for a network frequency is typically the largest and heaviest part of the entire converter.

The output inductor that smoothes the surge waves observable in the terminals of the motor could electrically be most optimal when it would only affect with frequency components of such a magnitude that only the edges of the surge voltages were smoothed.

The structure of an output inductor according to the prior art is similar to the input inductor. However, such an output inductor also attenuates a component of base frequency, whereby the terminal voltage of the motor is reduced. Such an inductor is also so massive that it cannot be placed into the specific frequency converter as an optional component, instead it is separately mounted.

Output inductor structures are also known which are effective only in high frequency components. What are used are for instance rings made of a material provided with an extremely high specific permeability that positioned around output busbars attenuate the voltage transients. A drawback with these components is that they are very expensive. Consequently they are generally used only as a "common mode" inductor, which is common for all phases, whereby the effect is restricted merely to prevent bearing currents. Another problem with such rings is the relatively large size thereof.

Another structure in use, which is only effective in large frequency components, comprises an inductor bar provided with an open magnetic path placed in each output phase, the structure of such an inductor bar resembles a winding around a pile of armature sheets. The problems associated with this structure include high costs and a fairly extensive need for space.

BRIEF DESCRIPTION OF THE INVENTION

It is an object of the invention to provide an inductor arrangement comprising input and output inductors for a frequency converter or a corresponding electrical apparatus so as to solve the problems mentioned above. The object of the invention is achieved with an inductor arrangement, characterized in what is stated in independent claim 1. The preferred embodiments of the inductor arrangement are disclosed in the dependent claims.

The invention is based on the idea that a core of an input inductor is also utilized in the structure of an output inductor. In the inductor arrangement according to the invention, the output inductor is provided by placing a certain portion of a conductor in each phase of the output adjacent to the core of the output inductor so that at least a part of the magnetic flux formed around the output conductor may penetrate into the core. In the inductor arrangement according to the invention the input and output inductor are in a sense combined.

The advantages of the inductor arrangement according to the invention in comparison with the prior art solutions are a less significant need for space and weight and more advantageous manufacturing costs.

BRIEF DESCRIPTION OF THE INVENTION

In the following the invention will be explained in greater detail by means of the preferred embodiments with reference to the accompanying drawings, in which:

  • Figure 1 shows a side view of a prior art input conductor seen obliquely from the top; and
  • Figure 2 shows an inductor arrangement according to an embodiment of the invention seen from the end of the inductor structure.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 shows a typical three-phase input inductor of a frequency converter, in which the routes along which magnetic fluxes 5 travel and close are also indicated. A core is composed of thin armature sheets in such a manner that the magnetic flux 5 formed around winding turns 3 of the input current of the frequency converter travels along the armature sheet everywhere except in air gaps 6 created on purpose. The magnetic flux 5 is most dense in the corners of the windows and most sparse in the outer corners and back parts of yokes 7 and 8.

Figure 2 shows an inductor arrangement according to an embodiment of the invention seen from the end of the inductor structure. The inductor arrangement in Figure 2 is formed of the input inductor of Figure 1 by placing a predetermined length of insulated current conductors 4 of the output of the frequency converter adjacent to the yoke 7 of the input inductor, and by adding an additional yoke 9 made of armature sheet adjacent to the upper yoke 7 so that each conductor 4 remains between the upper yoke 7 and the additional yoke 9.

In the structure shown in Figure 2, the additional yoke 9 is made of a similar armature sheet as the core, and the armature sheets of the additional yoke 9 are placed in parallel with the armature sheets of the core.

In the arrangement shown in Figure 2, the conductors 4 of the output of the frequency converter are placed along the back surface of the upper yoke 7 so that the conductors 4 are substantially parallel with the main direction of travel of the magnetic flux caused by the input current of the frequency converter and passing through the upper yoke 7 adjacent to the conductors. Then, the magnetic flux formed around each conductor by impact of the output current of the frequency converter penetrates into the upper yoke 7 in such a manner that the travel route thereof is substantially perpendicular in relation to the main direction of travel of the magnetic flux caused by the input current of the frequency converter, in which case the effect of the magnetic flux of the output inductor 2 on the magnetic flux of the input inductor is practically non-existent.

In the inductor arrangement illustrated in Figure 2, the additional yoke 9 is provided with grooves 11 for the conductors 4. In the arrangement of Figure 2 the grooves 11 are almost as deep as the conductors 4 so that the distance between the additional yoke 9 and the upper yoke 7 equals the size of the air gap 6. The magnetic flux 5 of each conductor 4 is thus closed through the yoke 7, the additional yoke 9 and two air gaps 6.

In the inductor arrangement according to a preferred embodiment of the invention the grooves 11 of the additional yoke 9 are formed to be as deep as the diameter of the conductor 4, whereby the magnetic flux formed by the current moving in the conductor 4 does not pass through a single actual air gap 6, but through several small air gaps formed of the surface insulator in the armature sheets. The division of an air gap into several parts along the route of the magnetic flux is preferable in view of the saturation and loss of the core and the additional yoke 9. If the small air gaps formed of the surface insulator of the armature sheets do not provide a sufficiently large air gap for the magnetic path, then an "actual" air gap 6 can be formed between the additional yoke 9 and the upper yoke 7 in accordance with Figure 2.

The inductor arrangement according to the invention can also be implemented also without the additional yoke 9 placed adjacent to the core, whereby the magnetic flux of each conductor 4 is closed mainly through the air. Thus the inductance of the output inductor 2 is substantially smaller than when the structure illustrated in Figure 2 is used.

The additional yoke 9 is therefore used for increasing the inductance of the output inductor 2. Shaping the additional yoke 9 appropriately enables to dimension the inductance of the output inductor as desired. The more armature sheets on the magnetic path, the greater the inductance.

In the solution shown in Figure 2 the additional yoke 9 is provided with three grooves 11, in other words one groove 11 for each phase. Each groove 11 is of the same length as the additional yoke 9. Each groove 11 is provided with one conductor 4 of the output of the frequency converter. Each conductor 4 thus proceeds alongside the core a distance that substantially equals the size of the upper yoke 7.

The distance that each conductor 4 of the output of the frequency converter moves alongside the core may be shorter or longer than in the solution shown in Figure 2. Placing the conductors 4 over a longer distance adjacent to the core allows increasing the inductance of the output inductor 2, and vice versa.

The same groove 11 may be provided with several portions of the same conductor 4. The additional yoke 9 may also comprise more than one groove 11 for one phase, in which case each groove 11 is provided with one or more portions of the same conductor 4.

The inductor arrangement according to the invention may comprise more than one additional yokes. In addition to an additional yoke 9 placed adjacent to the upper yoke 7, another additional yoke may be provided that is placed adjacent to the lower yoke 8. The additional yoke placed adjacent to the lower yoke 8 may be similar to the additional yoke 9 placed adjacent to the upper yoke 7. It is obvious that all additional yokes are placed adjacent to the conductors 4 of the output of the frequency converter. If an additional yoke is thus placed adjacent to the lower yoke 8, then a portion of the conductors 4 is placed between the lower yoke 8 and the additional yoke.

The grooves 11, in which the conductors 4 of the output side are placed, can be formed in the inductor arrangement according to the invention in the additional yoke or in the yoke of the core of the input inductor. It is also possible to provide an inductor arrangement, in which both the additional yoke and the yoke of the input inductor comprise grooves 11 ranged to receive the conductors 4.

The inductor arrangement in which the grooves of the conductors 4 are placed in the yoke of the input inductor can be implemented without the additional yoke 9 or with the additional yoke 9.

The inductor arrangement according to the invention is applicable to be used with such electrical apparatuses that provide interference of the above-mentioned type typical for the frequency converters to the input and output inductors thereof. The inductor arrangement according to the invention can be implemented as a single or multiple phase inductor arrangement.

It has been noted in the above specification that armature sheet can be used for manufacturing the core and the additional yoke 9. Here, armature sheet refers to a thin sheet made of steel provided with an insulated surface. The armature sheet is employed in magnetic circuits to reduce eddy-current losses. Especially when transformers are concerned the same thin sheet provided with an insulated surface is referred to as the transformer sheet.

It is apparent for those skilled in the art that the basic idea of the invention can be implemented in various ways. The invention and the embodiments thereof are therefore not restricted to the above examples but may vary within the scope of the claims.


Anspruch[de]
Induktoranordnung, umfassend einen zum Koppeln an die Eingangsseite einer elektrischen Vorrichtung angepassten Eingangsinduktor und einen zum Koppeln an die Ausgangsseite der elektrischen Vorrichtung angepassten Ausgangsinduktor (2), wobei der Eingangsinduktor einen Joche (7, 8) und Stützen (1) aufweisenden Kern und mehrere Wicklungsschleifen (3) für jede um den Kern gebildete Phase umfasst, dadurch gekennzeichnet, dass der Ausgangsinduktor (2) für jede Phase einen Leiter (4) aufweist, der angepasst ist, an den Ausgang der elektrischen Vorrichtung gekoppelt zu werden und von dem eine vorbestimmte Länge derart neben dem Kern des Eingangsinduktors angeordnet ist, dass während der Verwendung ein durch einen Ausgangsstrom der elektrischen Vorrichtung um den Leiter (4) induzierter magnetischer Fluss in einen Teil des Kerns des Eingangsinduktors auf derartige Weise eindringt, dass die Bewegungsrichtung des magnetischen Flusses im Wesentlichen rechtwinklig in Bezug auf die Hauptbewegungsrichtung eines magnetischen Flusses ist, der durch den Eingangsstrom der elektrischen Vorrichtung in diesem Teil des Kerns induziert wird. Induktoranordnung wie in Anspruch 1 beansprucht, dadurch gekennzeichnet, dass der Kern des Eingangsinduktors mindestens zwei Joche (7, 8) und mindestens zwei Stützen (1) derart umfasst, dass die Wicklungsschleifen (3) des Eingangsinduktors um eine Stütze (1) herum gebildet werden und der Teil des Kerns, in den der durch den Ausgangsstrom induzierte magnetische Fluss eindringt, ein Joch (7) ist. Induktoranordnung wie in Anspruch 1 oder 2 beansprucht, dadurch gekennzeichnet, dass sie mindestens ein neben einem Joch (7) des Kerns des Eingangsinduktors derart angeordnetes zusätzliches Joch (9) umfasst, dass sich die vorbestimmte Länge der neben dem Kern angeordneten Leiter (4) sich zwischen dem zusätzlichen Joch (9) und dem Joch (7) befindet. Induktoranordnung wie in Anspruch 3 beansprucht, dadurch gekennzeichnet, dass das zusätzliche Joch (9) mit einer Nute (11) für jeden Leiter (4) versehen ist, um den Leiter aufzunehmen. Induktoranordnung wie in Anspruch 3 oder 4 beansprucht, dadurch gekennzeichnet, dass der Kern und das zusätzliche Joch (9) aus Blechblättern gebildet sind und dass die Blechblätter des Kerns und des zusätzlichen Jochs (9) parallel zueinander angeordnet sind. Induktoranordnung wie in einem der Ansprüche 3 bis 5 beansprucht, dadurch gekennzeichnet, dass eine Luftlücke (6) zwischen dem zusätzlichen Joch (9) und dem Joch (7) des Kerns des Eingangsinduktors bereitgestellt ist. Induktoranordnung wie in Anspruch 1 beansprucht, dadurch gekennzeichnet, dass ein Joch (7, 8) des Kerns des Eingangsinduktors mit einer Nute (11) für jeden Leiter (4) versehen wird, der nahe bei dem Kern angeordnet ist, um den Leiter aufzunehmen.
Anspruch[en]
An inductor arrangement comprising an input inductor adapted to be coupled to the input side of an electrical apparatus and an output inductor (2) adapted to be coupled to the output side of the electrical apparatus, the input inductor comprising a core having yokes (7, 8) and columns (1), and several winding turns (3) for each phase formed around the core, characterized in that the output inductor (2) includes for each Phase a conductor (4), which is adapted to be coupled to the output of the electrical apparatus and a predetermined length of which is placed adjacent to the core of the input inductor such that during use a magnetic flux induced around the conductor (4) by an output current of the electrical apparatus penetrates into a part of the core of the input inductor in such a manner that the travel route of the magnetic flux is substantially perpendicular in relation to the main direction of travel of a magnetic flux induced by the input current of the electrical apparatus in said part of the core. An inductor arrangement as claimed in claim characterized in that the core of the input inductor comprises at least two yokes (7, 8) and at least two columns (1) such that the winding turns 3 of the input inductor are formed around a column (7) and the part of the core into which the magnetic flux induced by the output current penetrates is a yoke (7). An inductor arrangement as claimed in claim 1 or 2, characterized in that it comprises at least one additional yoke (9) placed adjacent to a yoke (7) of the core of the input inductor in such a man- I ner that the predetermined length of the conductors (4) placed adjacent to the core is between the additional yoke (9) and the yoke (7). An inductor arrangement as claimed in claim 23, characterized in that the additional yoke (9) is provided with a groove (11) for each conductor (4) in order to receive said conductor. An inductor arrangement as claimed in claim 3 or 4, characterized in that the core and the additional yoke (9) are formed of armature sheets and that the armature sheets of the core and the additional yoke (9) are placed parallel to each other. An inductor arrangement as claimed in any one of claims 3 to 5, characterized in that an air gap (6) is provided between the additional yoke (9) and the yoke (7) of the core of the input inductor. An inductor arrangement as claimed in claim 1, character-ized in that a yoke (7, 8) of the core of the input inductor is provided with a groove (11) for each conductor (4) placed adjacent to the core in order to receive the conductor.
Anspruch[fr]
Dispositif de bobine d'inductance comprenant une bobine d'inductance d'entrée adapté pour être couplé à l'entrée d'un dispositif électrique et une bobine d'inductance de sortie (2) adapté pour être couplé à la sortie du dispositif électrique, la bobine d'inductance d'entrée comprenant un noyau ayant des culasses (7, 8) et des colonnes (1) et plusieurs spires d'enroulement (3) pour chaque phase formées autour du noyau caractérisé en ce que la bobine d'inductance de sortie (2) comprend pour chaque phase un conducteur (4), qui est adapté pour être couplé à la sortie du dispositif électrique, et une longueur prédéterminée qui est adjacente au noyau de la bobine d'inductance d'entrée de telle sorte que durant l'utilisation un flux magnétique induit autour du conducteur (4) par un courant de sortie du dispositif électrique pénètre dans une partie du noyau de la bobine d'inductance d'entrée de façon que l'itinéraire de cheminement du flux magnétique soit essentiellement perpendiculaire à la direction principale du cheminement d'un flux magnétique induit par le courant d'entrée du dispositif électrique dans ladite partie du noyau. Dispositif de bobine d'inductance selon la revendication 1, caractérisé en ce que le noyau de la bobine d'inductance d'entrée comprend au moins deux culasses (7, 8) et au moins deux colonnes (1) de telle sorte que les spires d'enroulement (3) de la bobine d'inductance d'entrée soient formées autour d'une colonne (1) et de telle sorte que la partie du noyau dans lequel pénètre le flux magnétique induit par le courant de sortie est une culasse (7), Dispositif de bobine d'inductance selon la revendication 1 ou 2, caractérisé en ce qu'il comprend au moins une culasse supplémentaire (9) placée à côté d'une culasse (7) du noyau de la bobine d'inductance d'entrée de façon que la longueur prédéterminée des conducteurs (4) placés à côté du noyau soit entre la culasse supplémentaire (9) et la culasse (7). Dispositif de bobine d'inductance selon la revendication 3, caractérisé en ce que la culasse supplémentaire (9) comprend une encoche (11) pour chaque conducteur (4) afin de recevoir ledit conducteur. Dispositif de bobine d'inductance selon l'une des revendications 2, 3 ou 4, caractérisé en ce que le noyau et la culasse supplémentaire (9) sont formés par des feuillards et que les feuillards du noyau et de la culasse supplémentaire (9) sont placés parallèlement les uns par rapport aux autres. Dispositif de bobine d'inductance selon l'une quelconque des revendications 3 à 5, caractérisé en ce qu'un entrefer (6) est prévu entre la culasse supplémentaire (9) et la culasse (7) du noyau de la bobine d'inductance d'entrée. Dispositif de bobine d'inductance selon la revendication 1, caractérisé en ce qu'une culasse (7, 8) du noyau de la bobine d'inductance d'entrée comprend une encoche (11) pour chaque conducteur (4) placé à côté du noyau afin de recevoir le conducteur.






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