JP2013197275A - Exciter of rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the field winding of a synchronous motor including a rotary transformer which can divide a flow of eddy current going around the inside of segment bases 13c, 15c.SOLUTION: A stationary side core and a rotary side core are constituted, respectively, by combining a plurality of segments 13A, 15A, divided equally in the circumferential direction, annularly. At least in the segment bases 13c, 15c of each segment 13A, 15A, thus divided, a laminate metal piece 21 of soft magnetic body is embedded. According to the arrangement, a large eddy current in the circumferential direction can be divided because both cores 13, 15 are divided in the circumferential direction, and since a laminate metal piece 21 is embedded in the segment bases 13c, 15c, a flow of eddy current going around the inside of the segment bases 13c, 15c can also be divided. Since the eddy currents generated in both cores can be suppressed, eddy current loss can be reduced.

Description

  The present invention relates to a rotating electrical machine for home appliances, industrial use, and moving body, and more particularly to an exciting device for a rotating electrical machine suitable as a generator motor for an automobile having a rotor provided with a field winding.

In recent years, small and high-performance brushless motors using rare earth magnets such as neodymium are the mainstream of electric motors in recent years, but there is an urgent need to avoid the risk of securing resources due to the uneven distribution of rare earth magnets.
On the other hand, a winding field motor having a field winding in a rotor is known, but in order to cope with a brushless structure, it is necessary to transmit excitation power to be supplied to the field winding in a non-contact manner.
On the other hand, Patent Document 1 describes an excitation device using a rotary transformer. This excitation device can transmit excitation power in a non-contact manner from the primary side to the secondary side of the rotary transformer to supply power to the field windings of the rotor.

JP 2010-166787 A

However, in the conventional rotary transformer, as shown in FIG. 10, a large eddy current indicated by the illustrated arrow is generated in the circumferential direction of the transformer core 100, and eddy current loss becomes a problem. In particular, when the excitation frequency is increased in order to reduce the size of the device, there is a problem that an increase in eddy current loss becomes remarkable and a decrease in transmission efficiency becomes remarkable.
According to the results of research conducted by the present inventor to overcome the above problems, it is clarified that generation of eddy current can be reduced by dividing the transformer core 100 into a plurality of segments 110 in the circumferential direction as shown in FIG. It was done.

However, by dividing the transformer core 100 into a plurality of segments 110, there is a clear problem that a small eddy current flow (shown by arrows in the figure) that circulates inside the cross section of the segment 110 is newly generated as shown in FIG. Became.
The present invention has been made on the basis of the above circumstances, and its purpose is to provide a rotating transformer equipped with a rotating transformer that can reduce the flow of eddy current generated in a segment formed by dividing the transformer core in the circumferential direction. An object is to provide an electric excitation device.

  The present invention according to claim 1 is an exciter that is used in a rotating electrical machine having a field winding on a rotor that rotates integrally with a rotating shaft, and that supplies excitation power to the field winding. It has a set of coil units configured by winding a coil around an annular core made of a soft magnetic material, and this set of coil units is arranged to face each other with a gap, and a set of coil units Among them, one coil unit is arranged on the fixed side and the other coil unit is arranged on the rotation side, and the rotary transformer is arranged, and the core used for one coil unit is used for the fixed side core and the other coil unit. When the core to be rotated is referred to as a rotation-side core, the fixed-side core and the rotation-side core are each divided into a plurality of segments in the circumferential direction, and each segment has an eddy current circulating around the inside of the segment. Wherein the soft magnetic material dividing the record is embedded.

In the rotary transformer of the present invention, the fixed side core and the rotary side core are each divided in the circumferential direction, so that a large eddy current flowing in the circumferential direction of both cores can be divided. In addition, since the soft magnetic material is embedded in at least the segment base portion of each divided segment, the flow of eddy current circulating around the segment base portion can also be divided. Thereby, since the eddy current which generate | occur | produces in a fixed side core and a rotation side core can be suppressed, an eddy current loss can be reduced.
Note that the soft magnetic material is a metal piece obtained by forming a soft magnetic metal material into a plate shape (for example, a laminated iron piece formed by laminating electromagnetic steel plates or an amorphous metal piece formed by overlapping amorphous metal foils into a plate shape. By embedding in the direction perpendicular to or parallel to the segment base, only the flow of eddy currents circulating around both cores can be suppressed without obstructing the flow of the main magnetic flux of the rotary transformer.

It is a perspective view of the segment which embeds a lamination metal piece. It is a perspective view of a fixed side core and a rotation side core. It is a schematic block diagram of a synchronous motor and a rotation transformer. It is a circuit diagram of a synchronous motor and an excitation device. It is the figure which showed the effect (reduction of eddy current loss) of this invention with the bar graph. (Example 2) which is a perspective view of the segment which embed | buried the laminated metal piece. (Example 2) which is a perspective view of the segment which embed | buried the laminated metal piece. (Example 2) which is a perspective view of the segment which embed | buried the laminated metal piece. (Example 3) which is a perspective view of the segment which embed | buried the laminated metal piece. It is a perspective view of the transformer core which shows the eddy current which generate | occur | produces in the circumference direction. It is a perspective view which shows the transcore of a division structure. It is a perspective view of the segment which shows the flow of eddy current.

  The best mode for carrying out the present invention will be described in detail with reference to the following examples.

Example 1
In the first embodiment, an example in which the excitation device of the present invention is applied to a winding field type synchronous motor will be described. As shown in FIG. 3, the synchronous motor 1 includes a stator 4 in which an armature winding 3 is wound around a stator core 2, and a rotor 7 in which a field winding 6 is wound around a rotor core 5. It is supported by the motor rotating shaft 8 and is configured to be rotatable integrally with the motor rotating shaft 8.
The stator 4 is fixed to a motor housing (not shown).
The stator core 2 is configured by laminating a plurality of annular electromagnetic steel plates obtained by punching a plurality of slots at equal intervals in the circumferential direction on the radially inner peripheral side. As shown in FIG. 4, the armature winding 3 has three-phase (U-phase, V-phase, W-phase) phase windings that are star-connected, and each end Uo, Vo of this phase winding. , Wo are connected to the inverter 9.

The inverter 9 is a well-known power conversion device, converts DC power extracted from the battery B into AC power, and supplies the AC power to the armature winding 3. The winding specifications of the armature winding 3 may be either well-known concentrated winding or distributed winding.
As shown in FIG. 3, the rotor 7 is disposed opposite to the stator 4 with a predetermined gap on the inner diameter side. The rotor core 5 is formed by laminating a plurality of annular electromagnetic steel plates in which a plurality of slots are punched at equal intervals in the circumferential direction on the outer peripheral side in the radial direction, and is fixed to the outer periphery of the motor rotating shaft 8 by serration fitting or the like. . The field winding 6 is wound around the rotor core 5 according to the same winding specifications as the rotor structure described in Patent Document 1, for example, and a field current (DC) is supplied from the excitation device 10 (see FIG. 4). By forming an electromagnet, the magnetic poles of the rotor 7 are excited.

Next, the excitation device 10 of the present invention will be described.
As shown in FIG. 4, the exciter 10 includes a rotary transformer 11 that can transmit power from the primary side to the secondary side in a non-contact manner, and AC power transmitted to the secondary side is converted to DC power to convert the rotor 7 And a forward converter 12 that supplies the field winding 6.
As shown in FIG. 3, the rotary transformer 11 is composed of a fixed unit US and a rotary unit UR that are opposed to each other with a predetermined gap in the axial direction (left-right direction in the drawing). Are arranged concentrically with the motor rotating shaft 8.

As shown in FIG. 2, the fixed-side unit US includes a fixed-side core 13 having an annular coil space CS and a primary coil 14 accommodated in the coil space CS of the fixed-side core 13. The core 13 is fixed to the motor housing with a bolt or the like. In order to avoid contact with the motor rotation shaft 8 on the inner diameter side of the fixed core 13, a gap is secured between the fixed core 13 and the motor rotation shaft 8.
As shown in FIG. 2, the rotation-side unit UR includes a rotation-side core 15 having an annular coil space CS and a secondary coil 16 accommodated in the coil space CS of the rotation-side core 15. The side core 15 is fixed to the axial end surface of the rotor core 5 with bolts or the like. On the inner diameter side of the rotation-side core 15, a gap is secured between the rotation-side core 15 and the motor rotation shaft 8 in order to suppress the exchange of magnetic flux with the motor rotation shaft 8.

The primary coil 14 is concentrically wound around the coil space CS of the fixed core 13 and is fixed by impregnating an adhesive or the like. An alternating current is supplied to the primary coil 14 from a power source (not shown).
The secondary coil 16 is wound concentrically around the coil space CS of the rotary core 15 and is fixed by impregnating with an adhesive or the like. As shown in FIG. 4, the secondary coil 16 is connected to the field winding 6 of the rotor 7 via the forward converter 12, and an alternating current is induced in the secondary coil 16 by feeding the primary coil 14. Then, it is converted from alternating current to direct current by the forward converter 12 and is fed to the field winding 6.
For example, as shown in FIG. 4, the forward conversion device 12 includes a bridge-type full-wave rectifier circuit in which four rectifier elements (diodes 12a) are connected in a bridge shape. The forward conversion device 12 can also be configured by combining a rectifier circuit and a smoothing circuit.

  As shown in FIG. 2, the fixed side core 13 and the rotary side core 15 are each configured by combining a plurality of segments 13 </ b> A and 15 </ b> A that are equally divided in the circumferential direction (8 divisions in FIG. 2) in an annular shape. Insulating members 17 and 18 are sandwiched between adjacent segments 13A and 15A. That is, the segments 13A and 15A adjacent in the circumferential direction are electrically insulated by the insulating members 17 and 18, respectively. Further, the outer circumferences of the fixed side core 13 and the rotation side core 15 are all the segments 13A, 15A and insulating members 17 combined in an annular shape by the reinforcing members 19, 20 having higher electrical resistivity than the segments 13A, 15A, respectively. , 18 are held. The reinforcing members 19 and 20 are, for example, a fiber material or a reinforcing tape, and can be fixed by impregnating an adhesive.

The segments 13A and 15A of the cores 13 and 15 have a fan-shaped planar shape facing each other with a gap in the axial direction, and as shown in FIG. 1, arc-shaped inner peripheral walls provided on the inner peripheral side of the fan-shaped Segment base portions 13c and 15c formed between the portions 13a and 15a, the arc-shaped outer peripheral wall portions 13b and 15b provided on the outer peripheral side of the sector, and the inner peripheral wall portions 13a and 15a and the outer peripheral wall portions 13b and 15b. For example, it is manufactured by compression molding soft magnetic powder.
In addition, the inner peripheral ring part, the outer peripheral ring part, and the base part of both the cores 13 and 15 described in claim 2 of the present application are in a state in which a plurality of divided segments 13A and 15A are combined in an annular shape. The inner peripheral wall portions 13a and 15a of the segments 13A and 15A, the outer peripheral wall portions 13b and 15b, and the segment base portions 13c and 15c are respectively formed in an annular shape.

  In addition, a soft magnetic material that divides the flow of eddy current (see FIG. 12) that circulates inside the segment base portions 13c and 15c is embedded in the segment base portions 13c and 15c of the segments 13A and 15A. This soft magnetic body is, for example, a rectangular laminated metal piece 21 in which electromagnetic steel plates are laminated. As shown in FIG. 1, a plurality of the laminated metal pieces 21 are arranged at a predetermined interval in the circumferential direction of the segment base portions 13 c and 15 c (in the illustrated arc direction), and the longitudinal direction of the laminated metal pieces 21 is The inner peripheral wall portions 13a and 15a and the outer peripheral wall portions 13b and 15b of the segments 13A and 15A are embedded in a vertical direction orthogonal to the plane of the segment base portions 13c and 15c, in the radial direction facing each other. Moreover, the laminated metal piece 21 can also be embedded in a state of penetrating the segment base portions 13c and 15c in the plate thickness direction (vertical direction in the drawing).

(Operation and Effect of Example 1)
Since the rotary transformer 11 described in the first embodiment is configured by dividing the fixed core 13 and the rotary core 15 in the circumferential direction, the large eddy current in the circumferential direction shown in FIG. 10 can be divided. In particular, since the segments 13A adjacent to each other in the circumferential direction and the segments 15A are electrically insulated via the insulating members 17 and 18 respectively, eddy currents generated in the circumferential direction of both the cores 13 and 15 are further reduced. Can be divided reliably. Thereby, as compared with a conventional rotary transformer in which both cores 13 and 15 are not divided, eddy current loss can be greatly reduced (about 1/8) as shown in FIG.

  Furthermore, in Example 1, since the laminated metal piece 21 which is a soft magnetic body is embed | buried under the segment base part 13c, 15c of each segment 13A, 15A which divided | segmented both the cores 13 and 15, segment base part 13c, 15c The flow of the eddy current circulating around the inside (see FIG. 12) can be divided by the laminated metal piece 21. In this case, even if compared with a rotary transformer in which both cores 13 and 15 are simply divided into a plurality of segments 13A and 15A, that is, a rotary transformer in which no soft magnetic material is embedded in the segments 13A and 15A, it is shown in FIG. Thus, the effect which can further reduce an eddy current loss is acquired.

As a means for electrically insulating the segments 13A adjacent to each other in the circumferential direction and the segments 15A, the insulating members 17 and 18 described in the first embodiment are inserted between the two segments 13A and between the two segments 15A. Instead of this, it is also possible to employ a configuration in which gaps are provided between two adjacent segments 13A and between segments 15A.
In the rotary transformer 11 described in the first embodiment, since both the cores 13 and 15 are equally divided in the circumferential direction, all the segments 13A of the fixed side core 13 and all the segments 15A of the rotary side core 15 are Each can have the same shape. For this reason, cost reduction can be achieved by mass-producing the segments 13A and 15A of the same standard.

Further, by making the shape of the segments 13A, 15A of both the cores 13, 15 into a fan shape, the accommodation efficiency when the fixed side core 13 and the rotation side core 15 are configured by combining the plurality of divided segments 13A, 15A is improved. It is economical because it is the best.
Furthermore, since the outer periphery of the cores 13 and 15 divided into the plurality of segments 13A and 15A is held by the reinforcing members 19 and 20 having high electrical resistivity, respectively, both anti-centrifugal strength and eddy current reduction are achieved. ing.
In addition, since an air gap is secured between the rotation side core 15 and the motor rotation shaft 8, eddy current can be prevented from being induced to the iron motor rotation shaft 8. Instead of providing a gap on the inner peripheral side of the rotation side core 15, a configuration in which a nonmagnetic portion is disposed between the rotation side core 15 and the motor rotation shaft 8 may be adopted.

(Example 2)
As shown in FIG. 6, the second embodiment is an example in which a plurality of laminated metal pieces 21 are embedded radially from the inner diameter side to the outer diameter side of the segment base portions 13c and 15c. Same as 1.
Also in this configuration, the flow of eddy currents circulating around the segment base portions 13c and 15c can be divided by the laminated metal piece 21 embedded in the segment base portions 13c and 15c, so that the same effect as the first embodiment can be obtained. Can do.
In the example shown in FIG. 1 of the first embodiment and FIG. 6 of the second embodiment, the laminated metal piece 21 is embedded only in the segment base portions 13c and 15c. For example, as shown in FIG. 7 and FIG. Similarly, the laminated metal piece 21 can be embedded not only in the segment base portions 13c and 15c but also in the inner peripheral wall portion 13a and the outer peripheral wall portion 13b of the segments 13A and 15A.

(Example 3)
As shown in FIG. 9, the third embodiment is an example in which a plurality of laminated metal pieces 21 are embedded in parallel to the planes of the segment base portions 13 c and 15 c, and the other configuration is the same as the first embodiment.
In the above configuration, since the eddy current flowing in the thickness direction of the segment base portions 13c and 15c can be divided by the laminated metal piece 21, eddy current loss can be reduced as in the first embodiment.

(Modification)
In Example 1, although the laminated metal piece 21 which laminated | stacked the electromagnetic steel plate was described as an example of the soft magnetic body embed | buried in the segments 13A and 15A, as another example, for example, an amorphous metal foil was piled and shape | molded in plate shape. It is also possible to use amorphous metal pieces.
In the first embodiment, the number of divisions of the fixed side core 13 and the rotation side core 15 is described as the same number (8 divisions in FIG. 2), but the number of divisions of both the cores 13 and 15 may be different.
In Example 1, although the example which applied the excitation apparatus 10 of this invention to the synchronous motor 1 was described, it is also applicable to a synchronous generator.
In addition, the rotary transformer 11 described in the first embodiment has a configuration in which the fixed side unit US and the rotary side unit UR are opposed to each other with a gap in the axial direction, but the fixed side unit US and the rotary side unit UR May be configured to have a gap in the radial direction and to face each other.

1 Synchronous motor (rotary electric machine)
6 Field winding 7 Rotor 8 Motor rotating shaft (Rotating shaft)
10 Excitation Device 11 Rotating Transformer 12 Forward Conversion Device (Field Winding)
13 Fixed core (annular core)
13A Segment of fixed side core 13c Segment base 14 Primary coil 15 Rotation side core (annular core)
15A Rotation-side core segment 15c Segment base 16 Secondary coil 21 Laminated metal piece (soft magnetic material)
US fixed unit (one coil unit)
UR Rotation side unit (the other coil unit)

Claims (12)

An excitation device (1) used for a rotating electrical machine (1) having a field winding (6) on a rotor (7) that rotates integrally with a rotating shaft (8), and supplying excitation power to the field winding (6). 10)
The excitation device (10)
It has a set of coil units (US, UR) formed by winding coils (14, 16) around an annular core (13, 15) made of soft magnetic material, and this set of coil units (US , UR) are opposed to each other with a gap, and one coil unit (US) of the set of coil units (US, UR) is disposed on the fixed side, and the other coil unit (UR). Comprises a rotary transformer (11) arranged on the rotation side,
When the core used for the one coil unit (US) is called a fixed core (13), and the core used for the other coil unit (UR) is called a rotating core (15), the fixed side The core (13) and the rotating core (15) are each divided into a plurality of segments (13A, 15A) in the circumferential direction, and the segments (13A, 15A) include the segments (13A, 15A). And a soft magnetic body (21) that divides the flow of the eddy current that circulates in the interior of the rotating electrical machine. In the rotating electrical machine excitation device (10) according to claim 1,
The fixed core (13) and the rotary core (15) each form an annular coil space (CS) that accommodates the coils (14, 16), and an inner periphery of the coil space (CS). An inner ring portion that covers the outer peripheral side of the coil space (CS), an inner ring portion that covers the outer space side of the coil space (CS), An annular base that closes the gap,
The inner ring portion, the outer ring portion, and the segments (13A, 15A) corresponding to the base portion are divided into inner wall portions (13a, 15a), outer wall portions (13b, 15b), and , When called the segment base (13c, 15c),
An excitation apparatus for a rotating electrical machine, wherein the soft magnetic body (21) is embedded in at least the segment base (13c, 15c) of the segment (13A, 15A). In the excitation device (10) for a rotating electrical machine according to claim 2,
The soft magnetic body (21) is a metal piece (21) obtained by forming a soft magnetic metal material into a plate shape,
At least one of the metal pieces (21) is arranged along the radial direction of the segment (13A, 15A) and embedded in a vertical direction orthogonal to the plane of the segment base (13c, 15c). An exciting device for a rotating electric machine characterized by the above. In the excitation device (10) for a rotating electrical machine according to claim 3,
In the segment (13A, 15A), a plurality of the metal pieces (21) are embedded at a predetermined interval in at least the segment base (13c, 15c), and the plurality of metal pieces (21) are: An exciter for a rotating electrical machine, wherein the segment bases (13c, 15c) are arranged radially from an inner diameter side toward an outer diameter side. In the excitation device (10) for a rotating electrical machine according to claim 3 or 4,
The exciter for a rotating electrical machine, wherein the metal piece (21) is embedded through the segment base (13c, 15c) in the thickness direction. In the excitation device (10) for a rotating electrical machine according to claim 2,
The soft magnetic body is a metal piece (21) obtained by forming a soft magnetic metal material into a plate shape,
An excitation device for a rotating electrical machine, wherein at least one of the metal pieces (21) is embedded in parallel to a plane of the segment base (13c, 15c). In any one rotating electrical machine excitation device (10) according to claims 2-6,
The metal piece (21) is a laminated iron piece formed by laminating electromagnetic steel plates, or an amorphous metal piece formed into a plate shape by superposing amorphous metal foils, and an exciting device for a rotating electrical machine . In any 1 exciter (10) of a rotary electric machine described in Claims 1-7,
The segment (13A, 15A) is formed by compressing and molding magnetic powder. In any 1 exciter (10) of a rotary electric machine described in Claims 1-8,
The rotating machine core exciter according to claim 1, wherein the stationary core (13) and the rotating core (15) have the segments (13A, 15A) divided into a sector shape. In any 1 exciter (10) of a rotary electric machine described in Claims 1-9,
An exciter for a rotating electrical machine, wherein the stationary core (13) and the rotating core (15) are electrically insulated from each other in the circumferentially adjacent segments (13A, 15A). In any 1 exciter (10) of a rotary electric machine described in Claims 1-10,
The rotating-side core (15) is disposed concentrically with the rotating shaft (8), and has a nonmagnetic portion between the rotating shaft (8) and the exciting device for a rotating electrical machine. In any one rotating electrical machine excitation device (10) according to claims 1 to 11,
In the rotary transformer (11), the outer periphery of the fixed side core (13) and the rotary side core (15) is held by a reinforcing member (19, 20) having a higher electrical resistivity than both the cores (13, 15). An exciting device for a rotating electrical machine.

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