WO2011036723A1

WO2011036723A1 - Synchronous generator

Info

Publication number: WO2011036723A1
Application number: PCT/JP2009/004866
Authority: WO
Inventors: 多久征吾
Original assignee: 東芝三菱電機産業システム株式会社
Priority date: 2009-09-25
Filing date: 2009-09-25
Publication date: 2011-03-31
Also published as: JPWO2011036723A1; CN102577050A

Abstract

A synchronous generator is provided with a rotor (10) in which a plurality of projecting magnetic pole portions (12) projecting from the outer circumferential surface are arranged at intervals from one another in the circumferential direction, and which consists of a magnetic material, and a stator (20) covering the rotor (10) from the outside. The stator (20) comprises a stator iron core (22) in which a plurality of fixed projecting portions (24) which project from the inner circumferential surface toward the inside and are capable of facing each of the projecting magnetic pole portions (12) are arranged at intervals from one another in the circumferential direction and a static magnetic field is formed, and armature winding wires (26) which are formed by winding a coil around each of the fixed projecting portions (24) in the radial direction. The circumferential central portion of an outer end surface (14) of each of the projecting magnetic pole portions (12) projects radially outward than circumferential both ends thereof.

Description

Synchronous generator

The present invention relates to a synchronous generator having a field winding on a stator.

Many conventional generators for large wind turbines use a permanent magnet type synchronous generator. In a permanent magnet type synchronous generator, a rotor is generally provided with a permanent magnet, and a stator has an armature winding. A static magnetic field is formed by this permanent magnet.

Such a permanent magnet type synchronous generator uses a lot of expensive neodymium permanent magnets, and is therefore expensive. In place of such a high-cost permanent magnet type synchronous generator, there is one that uses a synchronous generator that excites a static magnetic field in the stator. For example, such a synchronous generator as disclosed in Patent Document 1 is known.

JP 2008-48584 A

Some stators of a synchronous generator that excites a static magnetic field have a protruding portion that protrudes radially inward on the inner peripheral surface of a ring-shaped member. The projecting portion is provided with a field winding for exciting a static magnetic field and an armature winding for generating an electromotive force. On the other hand, the rotor side often has a magnetic pole protruding in the radial direction on the outer peripheral surface of a ring made of a magnetic material.

When the rotor rotates, cogging torque may occur when the protrusions of the stator and the magnetic poles of the rotor intersect each other. When the value of the cogging torque is increased, vibration such as noise is generated. This vibration is a factor that reduces power generation efficiency and the like.

The present invention has been made to solve the above-described problems, and an object of the present invention is to reduce cogging torque generated when a synchronous generator that excites a static magnetic field generates power.

In order to achieve the above object, a synchronous generator according to the present invention includes a plurality of projecting magnetic pole portions formed so as to project radially outward from an outer peripheral surface and are arranged at intervals in the circumferential direction. An inner ring member made of a body, the inner ring-shaped member being configured to rotate about an axis, and covering the rotor from the radially outer side and projecting radially inward from the inner peripheral surface. A stator core having an outer ring-shaped member in which a plurality of fixed protrusions that can face each of the protruding magnetic pole parts are arranged at intervals in the circumferential direction; An armature winding formed by winding a coil around each portion in the radial direction; and a stator that covers the stator from the outside in the radial direction and fixes the stator. With housing In the synchronous generator having the above, the center part in the circumferential direction of the end face part facing outward in the radial direction of each protruding magnetic pole part is formed to protrude radially outward from both ends in the circumferential direction. And

In addition, the synchronous generator according to the present invention includes an inner ring made of a magnetic material in which a plurality of protruding magnetic pole portions formed so as to protrude radially outward from the outer peripheral surface are arranged at intervals in the circumferential direction. A rotor configured to rotate around its axis, and the inner ring-shaped member covering the rotor from the radially outer side and projecting from the inner peripheral surface toward the radially inner side to project each of the projecting magnetic poles A plurality of fixed protrusions that can be opposed to each of the respective parts, and a stator core having a static magnetic field formed by outer ring members arranged in the circumferential direction at intervals, and each of the fixed protrusions in a radial direction A stator having an armature winding formed by winding a coil around the housing, and a housing configured to cover the stator from the outside in a radial direction and fix the stator. Synchronous power generation In the circumferential direction central portion of the end surface portion facing the radially inner side of each of the fixed protrusion, that it is formed so as to protrude radially inward from circumferential ends, characterized by.

According to the present invention, it is possible to reduce the cogging torque generated when the synchronous generator that excites the static magnetic field generates power.

FIG. 3 is a schematic front view showing a part of the stator and the rotor of the synchronous generator according to the first embodiment of the present invention linearly developed in the circumferential direction when viewed from the axial direction. It is a schematic perspective view which shows the state which expand | deployed the stator of the synchronous generator of FIG. 1, a rotor, etc. to the rotating shaft direction, (a) is a rotor, (b) is a stator, (c) is a housing, (D) has shown the state which the synchronous generator was assembled. FIG. 3 is a schematic perspective view showing a set of armature windings and field windings formed on a stator iron core formed on the stator of FIG. 2. It is a schematic perspective view which shows a part of rotor of FIG. It is a front view which shows the example which generates a three-phase electromotive force with the synchronous generator of FIG. It is a schematic perspective view which shows a part of conventional rotor. It is a graph which shows the relationship between time and armature voltage when a rotor is rotating when the rotor of FIG. 5 is used. It is a graph which shows the relationship between time and armature voltage when a rotor is rotating when the rotor of FIG. 6 is used. FIG. 6 is a schematic front view showing a part of a stator and a rotor of a synchronous generator according to a second embodiment of the present invention as seen from the axial direction and linearly developed in the circumferential direction. FIG. 10 is a schematic front view showing a part of a stator and a rotor of a synchronous generator according to a third embodiment of the present invention as seen from the axial direction and linearly developed in the circumferential direction. It is a schematic perspective view which shows the synchronous generator which concerns on the 4th Embodiment of this invention.

Hereinafter, embodiments of a synchronous generator according to the present invention will be described with reference to the drawings.

[First Embodiment]
A first embodiment according to the present invention will be described with reference to FIGS. FIG. 1 is a schematic front view showing a part of the stator 20 and the rotor 10 of the synchronous generator according to the present embodiment as seen in the axial direction and linearly developed in the circumferential direction. FIG. 2 is a schematic perspective view showing a state where the stator 20 and the rotor 10 of the synchronous generator of FIG. 1 are developed in the direction of the rotation axis. FIG. 3 is a schematic perspective view showing a state in which the stator 20 and the rotor 10 of the synchronous generator of FIG. 1 are developed in the direction of the rotation axis, where (a) is the rotor 10 and (b) is the stator. 20, (c) shows the housing 30, and (d) shows a state where the synchronous generator is assembled. FIG. 4 is a schematic perspective view showing a part of the rotor 10 of FIG. FIG. 5 is a front view showing an example of generating a three-phase electromotive force in the synchronous generator of FIG.

FIG. 6 is a schematic perspective view showing a part of the conventional rotor 10. FIG. 7 is a graph showing the relationship between the time when the rotor 10 is rotating and the armature voltage when the rotor 10 of FIG. 5 is used. FIG. 8 is a graph showing the relationship between the time when the rotor 10 is rotating and the armature voltage when the rotor 10 of FIG. 6 is used.

First, the configuration of the synchronous generator of this embodiment will be described.

As shown in FIG. 2, the synchronous generator according to the present embodiment includes a rotor 10 having a ring-shaped rotor core 16 that can rotate around a horizontal axis 70, and a stator that covers the rotor 10 from the outside in the radial direction. And a housing 30 for covering the stator 20 from the outside in the radial direction and fixing the stator 20.

The rotor core 16 is a ring-shaped member made of a magnetic material such as a silicon steel plate and configured to be rotatable around a horizontal axis. A plurality of protruding magnetic pole portions 12 are formed on the outer peripheral surface of the rotor core 16 so as to protrude outward in the radial direction. These protruding magnetic pole portions 12 are arranged at intervals in the circumferential direction. The intervals between the protruding magnetic pole portions 12 are configured to be equal intervals. The protruding magnetic pole portion 12 will be described later.

Also, a rotating shaft (not shown) that rotates around a horizontal axis is arranged inside the rotor 10. The rotor 10 is fixed to the rotating shaft and rotates together with the rotating shaft.

The stator 20 has a stator core 22, an armature winding 26 disposed on the stator core 22, and a field winding 25 disposed in the vicinity of the armature winding 26.

The stator core 22 is a ring-shaped member made of a magnetic material such as a silicon steel plate, and is configured to cover the rotor 10 from the outside in the radial direction. A plurality of fixed projecting portions 24 projecting inward in the radial direction are formed on the inner peripheral surface of the stator core 22. These fixed projecting portions 24 are arranged at intervals in the circumferential direction, and can be opposed to the projecting magnetic pole portions 12 of the rotor 10. Here, the central angle formed by each of the adjacent fixed protruding portions 24 and the shaft 70 is configured to be equal to the central angle formed by each of the adjacent protruding magnetic pole portions 12 and the shaft 70.

The stator core 22 is configured to be divided for each fixed protrusion 24. That is, the stator core 22 includes a plurality of members including the fixed protrusions 24 shown in FIG. 3 arranged in the circumferential direction to form one ring.

Each of these fixed protrusions 24 is provided with a field winding 25 formed by winding a coil around the protrusion direction (radial direction). A static magnetic field is formed in the stator 20 by passing a direct current through the field winding 25. In the present embodiment, a static magnetic field is formed such that the direction of the magnetic flux becomes the arrow A shown in FIG.

Also, the fixed protrusion 24 is provided with an armature winding 26 on the inner side in the radial direction than the field winding 25. As with the field winding 25, the armature winding 26 is formed by winding a coil around the radial direction. The armature winding 26 is configured to generate an electromotive force or the like.

The inner front end surface 29 facing the radially inner side of each of the fixed projecting portions 24 is disposed so as to maintain a predetermined distance in the radial direction from the outer front end surface 14 facing the radially outer side of each projecting magnetic pole portion 12. ing.

Although not shown in detail, the stator 20 is fixed by the housing 30 as described above.

The outer front end face 14 of each protruding magnetic pole portion 12 of the rotor 10 is formed such that the central portion in the circumferential direction protrudes radially outward from both ends in the circumferential direction. As shown in FIGS. 1 and 4, the outer front end surface 14 of the present embodiment is formed with a partial cylindrical surface in which the center in the circumferential direction protrudes in the radial direction from both ends in the circumferential direction. The center of curvature of the partial cylindrical surface is configured to be radially outside the rotation center of the rotor 10, that is, the shaft 70.

Subsequently, a configuration in which the three-phase electromotive force is generated by the rotor 10 and the stator 20 configured as described above will be described.

As shown in FIG. 5, ten fixed protrusions 24 arranged adjacent to each other in the circumferential direction constitute one fixed protrusion 24 group. In this example, it has three fixed protrusion parts 24 group, ie, the 1st fixed protrusion part group 41, the 2nd fixed protrusion part group 42, and the 3rd fixed protrusion part group 43.

The first to third fixed projecting

portion groups

41, 42, 43 are arranged at intervals in the circumferential direction. The first to third fixed protruding

portion groups

41, 42, and 43 are arranged so that the circumferential interval is larger than the interval between the adjacent fixed protruding portions 24. The first to third

fixed protrusion groups

41, 42, and 43 each generate a one-phase electromotive force, and the first to third

fixed protrusion groups

41, 42, and 43 generate a three-phase electromotive force.

Next, the operation of this embodiment will be described.

When the rotor 10 rotates, that is, when the rotor 10 moves in the direction of the arrow R shown in FIG. 1, the outer tip surfaces 14 of the projecting magnetic pole portions 12 correspond to the inner tip surfaces 29 of the fixed projecting portions 24, respectively. Move while crossing each other.

Here, an example will be described in which the outer front end surface 14 of one protruding magnetic pole portion 12 moves so as to intersect each fixed protruding portion 24 in the radial direction. In this case, the protruding magnetic pole portion 12 moves in the direction of arrow R in FIG. 1 and intersects with each fixed protruding portion 24 in the direction of arrow R.

First, the vicinity of the end of the outer front end surface 14 on the rotation direction (direction indicated by the arrow R in FIG. 1) overlaps one end of the inner front end surface 29 in the radial direction. At this time, the circumferential center portion of the outer tip surface 14 does not overlap the inner tip surface 29 in the radial direction.

From this state, when the outer front end surface 14 moves in the rotation direction, the circumferential central portion of the outer front end surface 14 substantially overlaps the inner front end surface 29 in the radial direction. At this time, the outer front end surface 14 and the inner front end surface 29 face each other. Furthermore, when the rotor 10 rotates and the outer front end surface 14 moves in the rotational direction, the vicinity of the end opposite to the rotation direction of the outer front end surface 14 overlaps the inner front end surface 29 in the circumferential center portion.

After this, the outer front end face 14 moves to positions where the circumferential positions differ from each other with respect to the inner front end face 29. That is, the protruding magnetic pole portion 12 is in a state between the adjacent fixed protruding portions 24. After this, it moves so that it may approach the fixed protrusion part 24 which overlaps with a radial direction next.

The armature voltage changes according to the distance between the outer front end surface 14 and the inner front end surface 29. In the case of the protruding magnetic pole portion 12 having a partial cylindrical surface according to the present embodiment, the armature voltage changes as shown in FIG. The armature voltage is maximized when the outer tip surface 14 of the projecting magnetic pole portion 12 overlaps the inner tip surface 29 of the fixed projecting portion 24 in the radial direction. When the armature voltage is minimized, the armature voltage is minimized. This corresponds to the case where the portion 12 is between the adjacent fixed protrusions 24.

Here, a case where the outer front end surface 14 of the protruding magnetic pole portion 12 of the rotor 10 is flat will be described as a comparative example of the present embodiment.

As shown in FIG. 6, when the outer front end surface 14 is a flat surface, the armature voltage changes as shown in FIG. In this case, when the circumferential end of the outer tip surface 14 begins to overlap the inner tip surface 29, the distance between the outer tip surface 14 and the inner tip surface 29 decreases rapidly. For this reason, the waveform of the armature voltage has a steep slope near zero.

On the other hand, in the present embodiment, as shown in FIG. 5, the outer end surface 14 and the inner front end surface 29 are formed because the end in the circumferential direction is radially inward of the center in the circumferential direction of the outer end surface 14. When they start to overlap each other, it is possible to suppress the mutual distance from being rapidly reduced as compared with the comparative example.

For this reason, the waveform shown in FIG. 7 has a gentler slope near the armature voltage of zero than the waveform shown in FIG. 8, and FIG. 7 (the present embodiment) has a higher slope than the example of FIG. The waveform is close to a sine wave.

Thus, the cogging torque of the synchronous generator can be suppressed by suppressing the rapid change in the armature voltage.

As can be seen from the above description, according to the present embodiment, the outer tip surface 14 of the projecting magnetic pole portion 12 of the rotor 10 is a partial cylindrical surface, so that the waveform of the armature voltage becomes close to a sine wave. As a result, the cogging torque of the synchronous generator can be suppressed.

[Second Embodiment]
A second embodiment of the synchronous generator according to the present invention will be described with reference to FIG. FIG. 9 shows the stator 20 and the rotor 10 of the synchronous generator according to this embodiment, and a part of the stator 20 and the rotor 10 of the synchronous generator according to this embodiment is linear in the circumferential direction when viewed from the axial direction. It is a typical front view developed and shown in FIG. In addition, this embodiment is a modification of 1st Embodiment, Comprising: The same code | symbol is attached | subjected to the same part as 1st Embodiment, or a similar part, and duplication description is abbreviate | omitted.

In this embodiment, a partially convex cylindrical surface is formed on the inner front end surface 29 of the fixed protrusion 24 formed on the stator 20 as in the first embodiment. The outer front end surface 14 is formed with a substantially flat surface.

According to this embodiment, the cogging torque can be reduced as in the first embodiment.

[Third Embodiment]
A third embodiment of the synchronous generator according to the present invention will be described with reference to FIG. FIG. 10 shows the stator 20 and the rotor 10 of the synchronous generator according to the present embodiment, and a part of the stator 20 and the rotor 10 of the synchronous generator according to the present embodiment is linear in the circumferential direction when viewed from the axial direction. It is a typical front view developed and shown in FIG. In addition, this embodiment is a modification of 1st Embodiment, Comprising: The same code | symbol is attached | subjected to the same part as 1st Embodiment, or a similar part, and duplication description is abbreviate | omitted.

This embodiment is a combination of the features of the first embodiment and the features of the second embodiment. That is, a partially convex cylindrical surface is formed on each of the outer front end surface 14 and the inner front end surface 29.

As a result, the cogging torque can be reduced as in the first and second embodiments.

[Fourth Embodiment]
A fourth embodiment of the synchronous generator according to the present invention will be described with reference to FIG. FIG. 11 shows the stator 20 and the rotor 10 of the synchronous generator according to this embodiment, and a part of the stator 20 and the rotor 10 of the synchronous generator according to this embodiment is linear in the circumferential direction when viewed from the axial direction. It is a typical front view developed and shown in FIG. In addition, this embodiment is a modification of 1st Embodiment, Comprising: The same code | symbol is attached | subjected to the same part as 1st Embodiment, or a similar part, and duplication description is abbreviate | omitted.

In this embodiment, the combination of the stator 20 and the rotor 10 shown in FIG. 2 described in the first embodiment is arranged in three layers in the axial direction, and the first generator layer 51 and the second generator layer 52 are arranged. And the synchronous generator which has the 3rd generator layer 53 is comprised. Each layer is configured to generate an electromotive force corresponding to one phase and to generate a three-phase electromotive force in the first to third generator layers 51, 52, and 53.

This makes it easier to obtain a larger electromotive force in addition to the effects of the first embodiment.

[Other Embodiments]
The description of the above embodiment is an example for explaining the present invention, and does not limit the invention described in the claims. Moreover, each part structure of this invention is not restricted to the said embodiment, A various deformation | transformation is possible within the technical scope as described in a claim.

For example, the features of the fourth embodiment may be combined with the features of the second embodiment or the features of the third embodiment.

Moreover, although the static magnetic field is formed by providing the field winding 25 in the stator 20, it is not limited to this. For example, if it is a comparatively small thing, it is also possible to arrange | position a permanent magnet.

In the above embodiment, the outer tip surface 14 and the inner tip surface 29 are partial cylindrical surfaces, but are not limited thereto. For example, the circumferential ends may be chamfered.

DESCRIPTION OF SYMBOLS 10 ... Rotor, 12 ... Protruding magnetic pole part, 14 ... Outer front end surface, 16 ... Rotor iron core, 20 ... Stator, 22 ... Stator iron core, 24 ... Fixed protrusion part, 25 ... Field winding, 26 ... Electric machine Sub winding, 29 ... inner front end surface, 30 ... housing, 41 ... first fixed protruding portion group, 42 ... second fixed protruding portion group, 43 ... third fixed protruding portion group, 51 ... first generator layer, 52 ... 2nd generator layer, 53 ... 3rd generator layer

Claims

A plurality of protruding magnetic pole portions formed so as to protrude radially outward from the outer peripheral surface have an inner ring member made of a magnetic material arranged at intervals in the circumferential direction. A rotor configured to rotate about an axis;
An outer ring in which a plurality of fixed protrusions that cover the rotor from the outer side in the radial direction and protrude from the inner peripheral surface toward the inner side in the radial direction so as to face each of the protruding magnetic pole parts are arranged at intervals in the circumferential direction. A stator core comprising a stator member formed with a static magnetic field and an armature winding formed by winding a coil around each of the fixed protrusions in the radial direction;
A housing configured to cover the stator from outside in the radial direction and fix the stator;
In a synchronous generator having
The center part in the circumferential direction of the end face part facing the radially outer side of each protruding magnetic pole part is formed so as to protrude radially outward from both ends in the circumferential direction,
Synchronous generator characterized by
Each end face part of each projecting magnetic pole part is a partial cylindrical surface formed so that the central part in the circumferential direction protrudes from both ends in the circumferential direction, and the center of curvature of the partial cylindrical surface is more radius than the rotation center of the rotor. Configured to be on the outside,
The synchronous generator according to claim 1.
2. The synchronous generator according to claim 1, wherein both end surfaces of the projecting magnetic pole portions are chamfered at both ends in a circumferential direction.
The rotor has a plurality of the inner ring-shaped members stacked in the axial direction,
The stator has a plurality of outer ring-shaped members that are paired with the inner ring-shaped members and can face the projecting magnetic pole portions;
The synchronous generator as described in any one of Claim 1 thru | or 3 characterized by these.
One fixed protrusion group is formed by the plurality of fixed protrusions adjacent in the circumferential direction,
Three fixed protrusions are arranged on the inner peripheral surface of the outer ring member at intervals in the circumferential direction, and the intervals between the fixed protrusions adjacent to each other in the circumferential direction are determined by the fixed protrusions. It is formed to be larger than the circumferential interval between the adjacent fixed protrusions in the group,
Each of the three groups of fixed protrusions is configured to generate a one-phase electromotive force and to generate a three-phase electromotive force in the three groups;
The synchronous generator according to any one of claims 1 to 4, wherein
Three ring member pairs formed by a pair of the inner ring member and the outer ring member facing each other in the radial direction are stacked in the axial direction to form a set of ring members.
Each ring member pair is configured to generate a one-phase electromotive force and to generate a three-phase electromotive force in a set of ring member groups,
The synchronous generator according to any one of claims 1 to 4, wherein
The center part in the circumferential direction of the end face part facing inward in the radial direction of the fixed protruding part is formed so as to protrude inward in the radial direction from both sides of the circumferential end part,
The synchronous generator according to any one of claims 1 to 6, wherein:
A plurality of protruding magnetic pole portions formed so as to protrude radially outward from the outer peripheral surface have an inner ring member made of a magnetic material arranged at intervals in the circumferential direction. A rotor configured to rotate about an axis;
An outer ring in which a plurality of fixed protrusions that cover the rotor from the outer side in the radial direction and protrude from the inner peripheral surface toward the inner side in the radial direction so as to face each of the protruding magnetic pole parts are arranged at intervals in the circumferential direction. A stator core comprising a stator member formed with a static magnetic field and an armature winding formed by winding a coil around each of the fixed protrusions in the radial direction;
A housing configured to cover the stator from outside in the radial direction and fix the stator;
In a synchronous generator having
The center portion in the circumferential direction of the end surface portion facing the radially inner side of each of the fixed protruding portions is formed so as to protrude radially inward from both ends in the circumferential direction,
Synchronous generator characterized by
9. The synchronization according to claim 1, wherein a field winding is formed on each of the fixed protrusions on the radially inner side of the armature winding. 10. Generator.