CN116155002A - Double-fed wind generator rotor connecting wire structure, wound rotor and its generator - Google Patents

Abstract

The invention belongs to the technical field of wind power generators, and relates to a doubly-fed wind power generator rotor connection wire structure, a wound rotor and a generator thereof. The wound rotor, through the improvement of the rotor connecting wire fixing frame, rotor zero ring, reinforcing support frame, and rotor connecting wire arc bending structure, forms a wound rotor with an integrated rotor connecting wire structure. After installation The wound rotor has higher reliability and better mechanical performance for life testing under severe working conditions; at the same time, by improving the compact structure of the rear rotor fan, the shaft of the rotor fan to the rotor core and rotor winding The vertical distance is shortened, thereby improving the space utilization rate inside the generator, and at the same time, it also has a certain improvement effect on the temperature rise performance of the generator rotor.

Description

Double-fed wind generator rotor connecting wire structure, wound rotor and its generator

technical field

The invention belongs to the technical field of wind power generators, and relates to a wound generator rotor, in particular to a doubly-fed wind power generator rotor connecting wire structure, a wound rotor and a generator thereof.

Background technique

As the power level of wind turbines and the cost pressure of the wind power industry continue to increase, the space in the cabin of wind turbines can be described as "every inch of land" to improve the reliability of the generator, improve the utilization of the internal space of the generator, and reduce the cost of wind power generation. Cost is a technical problem that must be solved. Therefore, how to make full use of the space in the limited space of the nacelle and the generator while improving the reliability of the generator and its components has become the key to the design of the wind turbine.

At present, the fixed structure of the connecting wire and the zero ring of the mainstream wound rotor at home and abroad is shown in Figure 3. The rotor core 10, the rotor winding support 2 and the rotor connecting wire fixing frame 3 are fixed by means of an interference fit connection with the rotating shaft 11 through their respective inner circles; 9 or the rotor zero ring 13 are connected, and the rotor connecting wire 5 is bound and fixed with the rotor connecting wire fixing frame 3 (the cross-section has a groove for binding and positioning, but it is not a closed structure) through an insulating binding tape 6; the rotor zero ring 13 is fixed on the surface of the rotating shaft 11 through the insulating binding tape 6 of the outer ring; the rotor connection wire 5 and the rotor lead-out wire 9 are important components for the two-way energy flow between the converter and the rotor winding 4, and their reliability design is directly related to the wind power. The running stability of the generator set.

However, the existing wound rotor still has the following deficiencies: first, the function of the rotor connecting wire fixing frame is single, and the reliability of this fixing structure under severe working conditions is at risk; second, the 90° bend of the rotor connecting wire The R angle is usually implemented in accordance with the national standard, and there is a risk of stress concentration under severe working conditions; third, the reliability of the fixed structure of the rotor zero ring is at risk under severe working conditions; fourth, the rotor connection line, rotor zero ring, The structural integrity of the rotor winding support is not good; fifth, the axial space between the rotor connection line and the fan (or between the end cover and the end cover if there is no fan) is not fully utilized.

Contents of the invention

The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art, and provide a doubly-fed wind power generator rotor connecting wire structure, a wound rotor and a generator thereof. The wound rotor provides a more reliable fixed structure for the rotor connection line and the rotor zero ring, and at the same time reduces the overall axial space occupancy of the rotor (including the fan), and improves the rotor structure of the doubly-fed wind turbine. Reliability under harsh conditions.

To achieve the above object, the present invention provides the following technical solutions:

In the first aspect, the present invention provides a doubly-fed wind power generator rotor connection wire structure, which includes an integrally formed rotor connection wire body, the rotor connection wire body includes a first connecting portion connected to the rotor winding, and the first Below the first connecting part, there are sequentially distributed a twisted connecting part, a second connecting part connected to the end face of the rotor winding support, and an arc-shaped connecting part for reducing the stress at the bending part of the rotor connecting wire body. The horizontal third connection part is connected; the connection between the second connection part and the arc-shaped connection part forms a first transitional arc, and the connection between the arc-shaped connection part and the horizontal third connection part A second transitional arc is formed, and a third transitional arc is formed between the first transitional arc and the second transitional arc.

Further, the degrees of the central angles corresponding to the first transitional arc and the second transitional arc are both between 135° and 180°.

Further, the respective arc radii of the first transitional arc, the second transitional arc and the third transitional arc are all between X and 2X, where X is the thickness of the main body of the connecting wire of the rotor.

Further, the central angle of the third transition arc is 90°.

In the second aspect, the present invention provides a wound rotor, including a rotating shaft, a rotor core, a rotor winding, a rotor winding support, a rotor connection wire, a rotor zero ring, a rotor lead wire, and a rotor connection wire fixing frame; wherein, the The rotor connection line adopts the structure of the rotor connection line described in part or all above;

The rotor winding is embedded in the rotor core, and protrudes from the end face of the rotor core along the axial direction of the rotating shaft, and the protruding part is supported by the rotor winding bracket, and the protruding part is connected with the rotor zero ring and the rotor lead wire through the rotor connecting wire;

The section of the rotor connecting wire fixing frame is "D" shape, its vertical side is connected with the rotor winding support, and the arc side is bound and fixed with the rotor connecting wire by insulating binding tape;

A rotor zero-ring limiting ring is sleeved on the rotating shaft, and the rotor zero-ring is axially embedded in the gap between the rotor zero-ring limiting ring and the rotating shaft, and the gap is filled with insulating blocks;

A rotor fan is also installed on the rotating shaft, and the rotor fan is located on the right side of the rotor lead-out line; the inner circle of the rotor fan is provided with a gap for avoiding the rotor connection line and the fixed structure on the surface of the rotating shaft.

Further, three of the rotor connection lines are connected to the rotor zero ring, and the other three are connected to the rotor lead-out lines, and the axial lead-out directions of the two are opposite.

Further, the rotor zero ring limit ring adopts a full circle or a full circle groove, or adopts a circle or a circle formed by segmented arcs. Specifically, the rotor zero-ring limiting ring may be a circular ring additionally installed on the rotor winding support, or may be a groove processed by the rotor winding support.

Further, the rotor connecting wire fixing frame is welded and fixed on the end surface of the rotor winding support, and the rotor connecting wire fixing frame is made of round steel or flat steel.

Further, the fixed frame of the rotor connecting wire is also provided with a special-shaped reinforcing support frame, which is used to enhance the rigidity of the fixing frame of the rotor connecting wire, so that during the operation of the generator, when the rotor connecting wire is subjected to the same centrifugal force, a stronger Small deformation or displacement.

Furthermore, in order to realize the overall lightweight design of the rotor winding support, finite element simulation software was used to analyze and reduce the weight of the traditional "right-angled triangle-like" reinforcing support frame, and remove the part with less force, and finally formed A special-shaped reinforced support structure similar to an oblique "I"-shaped structure, and the weight of the special-shaped reinforced support structure is reduced by 50% compared with that before lightening, but the supporting strength can fully meet the needs of supporting strength.

In a third aspect, the present invention also provides a wind power generator, comprising the wound rotor described in part or all above. Since the axial distance from the rotor fan to the rotor core and the rotor winding is shortened in the wind generator, the temperature rise performance of the generator rotor is also improved to a certain extent while improving the utilization rate of the inner space of the generator.

Compared with the prior art, the technical solution provided by the present invention includes the following beneficial effects: by improving the structure of the rotor connecting line fixing frame, the rotor zero ring, the reinforcing support frame, and the arc bending structure of the rotor connecting line, an integrated rotor is formed. The wound rotor with connecting wire structure is tested for life under severe working conditions after installation. The wound rotor has higher reliability and better mechanical performance.

As far as the wind generator is concerned, due to the improved compact structure of the rotor fan, the axial distance from the rotor fan to the rotor core and rotor winding is shortened, thereby improving the space utilization ratio inside the generator, and improving the generator rotor The temperature rise performance also has a certain improvement effect.

Description of drawings

The accompanying drawings are incorporated in and constitute a part of this specification, and together with the description, serve to explain the principles of the invention.

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, In other words, other drawings can also be obtained from these drawings without paying creative labor.

Fig. 1 is a schematic diagram of the existing rotor connection line structure;

Fig. 2 is a schematic diagram of the structure of the rotor connecting wire provided by the present invention;

Fig. 3 is a structural diagram of an existing wound rotor;

Fig. 4 is a structural diagram of a wound rotor provided by the present invention;

Fig. 5 is a structural diagram of the rotor winding support provided by the present invention;

Fig. 6 is a schematic diagram of the structure of the special-shaped reinforcing support frame before and after lightening provided by the present invention;

Fig. 7 is a structural diagram of the rotor fan provided by the present invention.

Among them: 1. Rotor winding; 2. Rotor winding support; 3. Rotor connecting wire fixing frame; 4. Special-shaped reinforcing support frame; 5. Rotor connecting wire; 6. Insulation binding tape; 8. Rotor fan; 9. Rotor lead wire; 10. Rotor core; 11. Rotating shaft; 12. Rotor zero ring limit ring; 13. Rotor zero ring; 14. First connection part; 15. Torsion connection part; 16. The second connecting part; 17, the arc-shaped connecting part; 18, the third connecting part; 19, the notch.

Detailed ways

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numerals in different drawings refer to the same or similar elements unless otherwise indicated. The implementations described in the following exemplary examples do not represent all implementations consistent with the present invention. Rather, they are merely examples of structures consistent with aspects of the invention as recited in the appended claims.

In order to enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

Example 1

As shown in FIG. 2 , this embodiment provides a doubly-fed wind turbine rotor connecting wire structure, which includes an integrally formed rotor connecting wire body, and the rotor connecting wire body includes a first connecting portion connected to the rotor winding 1 14. Below the first connecting part 14, the torsional connecting part 15, the second connecting part 16 connected to the end surface of the rotor winding support 2, and the arc-shaped connecting part used to reduce the stress at the bend of the rotor connecting wire body are distributed in sequence. 17. The arc-shaped connecting portion 17 is in contact with the horizontal third connecting portion 18; the connection between the second connecting portion 16 and the arc-shaped connecting portion 17 forms a first transition arc, and the arc-shaped The connection between the connecting portion 17 and the horizontal third connecting portion 18 forms a second transitional arc, and a third transitional arc is formed between the first transitional arc and the second transitional arc.

Further, the reason why the twisted connecting portion 15 is twisted is to better match the connection between the rotor connecting wire body and the rotor winding 1 and the rotor lead-out wire 9 . Specifically, if the “twisted” twist is not performed, and the main body of the rotor connecting wire is directly bent down in the direction of connecting with the end of the rotor winding 1, the thickness of the bent part must be much greater than its width; The radial direction and the axial direction take up more space. On the other hand, if the above cross-section (the cross-section without twisting) is bent, the welding area of the rotor connection wire body and the rotor lead-out wire 9 will also be reduced. Insulation is also more difficult to do. And if in order to ensure the welding area and the insulation process, the cross-section of the rotor lead wire 9 is also erected, it will take up more space inside the shaft hole, and also reduce the insulation reliability.

Further, the degrees of the central angle α corresponding to the first transitional arc and the central angle β corresponding to the second transitional arc are both between 135° and 180°. Wherein, the degree of the central angle α depends on the distance from the left side of the rotor connecting line body to the rotor support on the core side, and the degree of the central angle β depends on the distance from the bottom of the rotor connecting line body to the rotating shaft 11 .

Further, the respective arc radii of the first transitional arc, the second transitional arc and the third transitional arc are all between X and 2X, where X is the thickness of the main body of the connecting wire of the rotor.

Preferably, the arc radii corresponding to the first transition arc, the second transition arc, and the third transition arc are all 1.5X, and X is the thickness of the rotor connecting wire body.

Further, the central angle of the third transition arc is 90°.

Specifically, the body of the rotor connection line optimizes the large arc structure at the bend, changing from the original one-time bend to the three-fold bend structure of "reverse bend-large arc bend-forward bend". Under the premise of not occupying additional space, the stress concentration at the bend of the rotor connection line 5 is avoided to the greatest extent, its force performance in the generator rotor is improved, and the overall reliability of it and the rotor is improved.

The rotor connecting line structure, through the three-fold bending design of "reverse bending-big arc bending-forward bending", can make the length of the rotor connecting line bend 7 under the condition of the same bending radius The longer the length, the longer the length of the rotor connection line bending part 7, the relatively smaller strain will be generated under the same stress. Comparing the arc length of bending in the existing structure (Fig. 1) and the arc length of bending in the structure of the present invention (Fig. 2), the ratio of the arc length of the two is 23.5/38. There is strain at the bend of the structure, and the strain at the bend at the bend 7 of the rotor connection line in the present invention is reduced.

Example 2

On the basis of Embodiment 1, this embodiment provides a wound rotor, as shown in FIG. 4 , including a rotating shaft 11, a rotor core 10, a rotor winding 1, a rotor winding support 2, a rotor connecting wire 5, and a rotor zero ring 13. . The rotor lead wire 9 and the rotor connecting wire fixing frame 3; the rotor connecting wire 5 adopts the rotor connecting wire structure as described above;

The rotor winding 1 is embedded in the rotor core 10, and protrudes from the end face of the rotor core 10 along the axial direction of the rotating shaft 11, and the protruding part is supported by the rotor winding support 2, and the protruding part is connected to the rotor zero through the rotor connecting wire 5. The ring 13 and the rotor lead wire 9 are connected; the rotor winding support 2 is connected with the rotating shaft 11 by an interference fit through its inner circle, and the rotor connection line fixing frame 3 and its special-shaped compensation support frame 4 are all part of the rotor winding support 2 ;

The cross-section of the rotor connecting wire fixing frame 3 is "D" shape, its vertical side is connected with the rotor winding support 2, and the arc side (near the rotor connecting wire side) is vertically connected with the rotor connecting wire 5 through the insulating binding tape 6. Partial binding and fixing; Among them, the arc part is conducive to the binding and fixing of the insulating binding tape 6. Due to the closed section of the "D" structure, the insulating binding tape 6 is prevented from being separated from the rotor connecting line 5 when the rotor connecting line 5 is subjected to strong centrifugal force. Rack 3 risks;

The rotor zero ring limiting ring 12 is sleeved on the rotating shaft 11, and the rotor zero ring 13 is embedded in the gap between the rotor zero ring limiting ring 12 and the rotating shaft 11 along the axial direction, and the gap is filled with insulating blocks ;

A rotor fan 8 is also installed on the rotating shaft 11, and the rotor fan 8 is located on the right side of the rotor lead-out line 9; the inner circle of the rotor fan 8 is provided with a gap for avoiding the fixed structure of the rotor connecting line 5 and the surface of the rotating shaft 11 19 (see Figure 7).

Further, three of the rotor connection wires 5 are connected to the rotor zero ring 13, and the other three are connected to the rotor lead-out wire 9, and the axial lead-out directions of the two are opposite.

Further, the rotor zero-ring limiting ring 12 adopts a full circle or a full circle groove, or adopts a circle or a circle formed by segmented arcs.

Specifically, in the existing rotor structure, the rotor zero ring 13 and the rotor lead-out wire 9 are led out in the same direction relative to the rotor connecting wire 5, specifically: three rotor connecting wires 5 are connected to the rotor zero ring 13, The rotor zero ring 13 is close to the rotor connection line 5 in the axial direction, and the other three rotor connection lines 5 are connected to the rotor lead-out lines 9 , and their connection positions are located outside the rotor zero ring 13 in the axial direction. However, in the rotor structure provided by the invention, the direction of the rotor zero ring 13 and the rotor lead-out wire 9 relative to the rotor connecting wire 5 is opposite; specifically: the rotor zero ring 13 is axially embedded in the rotor zero-ring limit ring 12 (or the rotor zero-ring limiting slot) and the shaft 11, the gap between the rotor zero-ring 13 and the rotor zero-ring limiting ring 12 (or the rotor zero-ring limiting slot) and the rotor connection line 5 is filled by an insulating block The fixed structure of the rotor zero ring 13 after vacuum pressure impregnation and drying can obtain higher reliability and operation stability than the existing wire-wound rotor zero ring fixed structure. Even if the rotor zero ring 13 is deformed by centrifugal force under extreme working conditions, under the restriction of the rotor zero ring limit ring 12 (or the rotor zero ring limit groove), the deformation of the rotor zero ring 13 will be very limited, so as not to Cracks or even failures such as breakage occur.

Further, a special-shaped reinforcing support frame 4 is also arranged in the rotor connection wire fixing frame 3 .

Specifically, in order to improve the rotor connection wire fixing frame 3 after the rotor connection wire 5 is bound and fastened and dipped and solidified, the rotor winding 1 (coil) and the rotor connection wire 5 are subjected to strong centrifugal force when the rotor rotates at high speed and the speed changes rapidly. The mechanical performance (including its rigidity) under the action prevents it from being repeatedly pulled and deformed by the rotor connecting wire 5, which can better fix the rotor connecting wire 5 and ensure that the rotor connecting wire 5 will not be deformed or broken due to changes in centrifugal force . For this reason, a special-shaped reinforcing support frame 4 is provided on the outside or inside of the rotor connection wire fixing frame 3 to avoid deformation or even fracture failure when subjected to strong centrifugal force and circumferential force.

Optionally, as shown in FIGS. 5-6 , the basic shape of the section of the special-shaped reinforcing support frame 4 is approximately a right triangle, which can be arranged inside or outside the closed section (with a certain depth) of the rotor connecting line fixing frame 3 . Its structural feature is that the two right-angled sides are respectively connected with the rotor winding support 2 and the rotor connecting wire fixing frame 3, and its thickness is similar to that of the rotor connecting wire fixing frame 3. Due to the stability of the triangle, this structural design can effectively fix the rotor connecting wire Frame 3 is reinforced to better cope with centrifugal force and circumferential force.

Preferably, in order to realize the lightweight design requirements of the rotor winding support 2, the relevant research and development personnel of the present invention use finite element simulation software to analyze the force situation of the special-shaped reinforcing support frame 4, reduce the weight, and use the smaller force Partially removed, the final structure obtained is a slanted "I"-shaped special-shaped reinforcement support frame 4, and the weight of the special-shaped reinforcement support frame 4 is 50% lighter than before lightweighting, but the support The strength can fully meet the needs of supporting strength.

Further, the material of the rotor connecting wire fixing frame 3 includes but not limited to metal materials, and its manufacturing methods include but not limited to welding, cutting, casting and 3D printing. Preferably, the rotor connecting wire fixing frame 3 is made of round steel or flat steel, and is welded and fixed on the end face of the rotor winding support 2 after bending, which has the advantages of simple manufacture, low cost, and good manufacturability.

Further, as shown in FIG. 7 , in order to realize that the right-angled part of the inner circle of the rotor fan 8 close to the rotor connection line 5 and the rotor lead-out line 9 avoids the space extending from the shaft hole where the rotor lead-out line 9 is located, the rotor fan 8 The inner circle is provided with a notch 19 for avoiding the fixing structure of the rotor connecting wire 5 and the surface of the rotating shaft 11 . The above design makes full use of the internal space of the generator without reducing the reliability of the rotor fan 8. The avoidance of the rotor fan 8 can be done in a full circle, or only in the part affected by the three rotor lead-out lines 9 avoid.

In addition, the present embodiment also provides a wind power generator, especially a doubly-fed wind power generator, including the wound rotor described in part or all above.

After installation, the life test of a double-fed wind turbine (equipped with the above-mentioned wound rotor structure) under severe working conditions shows that the wound rotor has higher reliability and better mechanical properties; at the same time, through the improvement The compact structure of the rear rotor fan 8 shortens the axial distance from the rotor fan 8 to the rotor core 10 and the rotor winding 1, thereby improving the space utilization rate inside the generator and at the same time, having a certain effect on the temperature rise of the generator rotor improvement effect.

The above descriptions are only specific embodiments of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention.

It should be understood that the present invention is not limited to what has been described above, and various modifications and changes can be made without departing from the scope thereof. The scope of the invention is limited only by the appended claims.

Claims (10)

1. A doubly-fed wind power generator rotor connecting wire structure, characterized in that it includes an integrally formed rotor connecting wire body, and the rotor connecting wire body includes a first connecting portion (14) connected to the rotor winding (1) , below the first connecting part (14), there are sequentially distributed the torsion connecting part (15), the second connecting part (16) connected to the end surface of the rotor winding support (2) and the bending part for weakening the rotor connecting wire body The arc-shaped connecting portion (17) of stress, the arc-shaped connecting portion (17) is connected with the third horizontal connecting portion (18); the second connecting portion (16) is connected with the arc-shaped connecting portion The junction of (17) forms the first transitional arc, and the junction of the arc-shaped connecting portion (17) and the horizontal third connecting portion (18) forms the second transitional arc, and the first transitional circle Between the arc and the second transition arc is a third transition arc. 2. The doubly-fed wind turbine rotor connecting line structure according to claim 1, characterized in that the degrees of the central angles corresponding to the first transitional arc and the second transitional arc are all between 135° and 180° ° between. 3. The rotor connection line structure of a doubly-fed wind power generator according to claim 1, wherein the respective arc radii of the first transitional arc, the second transitional arc, and the third transitional arc are between Between X and 2X, where X is the thickness of the main body of the rotor connecting wire. 4 . The doubly-fed wind turbine rotor connection line structure according to claim 1 , wherein the central angle of the third transitional arc is 90°. 5. A wound rotor, comprising a rotating shaft (11), a rotor core (10), a rotor winding (1), a rotor winding support (2), a rotor connecting wire (5), a rotor zero ring (13), and a rotor lead out wire (9) and rotor connecting wire fixing frame (3); it is characterized in that, the rotor connecting wire (5) adopts the rotor connecting wire structure as described in any one of claims 1-4; The rotor winding (1) is embedded in the rotor core (10), and protrudes from the end face of the rotor core (10) along the axial direction of the rotating shaft (11), and the protruding part is supported by the rotor winding bracket (2). Part of it is connected with the rotor zero ring (13) and the rotor lead wire (9) through the rotor connecting wire (5); The section of the rotor connecting wire fixing frame (3) is "D" shape, its vertical side is connected with the rotor winding support (2), and the arc-shaped side is bound and fixed with the rotor connecting wire (5) by an insulating binding band (6) ; The rotor zero ring limiting ring (12) is sleeved on the rotating shaft (11), and the rotor zero ring (13) is embedded in the gap between the rotor zero ring limiting ring (12) and the rotating shaft (11) in the axial direction Inside, the gap is filled with insulating blocks; A rotor fan (8) is also installed on the rotating shaft (11), and the rotor fan (8) is located on the right side of the rotor lead-out line (9); The gap (19) of the fixed structure on the surface of the wire (5) and the rotating shaft (11). 6. The wound rotor according to claim 5, characterized in that three of the rotor connection lines (5) are connected to the rotor zero ring (13), and the other three are connected to the rotor lead-out line (9) , and the axial extraction directions of the two are opposite. 7. The wound rotor according to claim 5, characterized in that, the rotor zero-ring limit ring (12) adopts a full circle or a full circle groove, or a circle formed by segmented arcs or round groove. 8. The wound rotor according to claim 5, characterized in that, the rotor connecting wire fixing frame (3) is welded and fixed on the end surface of the rotor winding support (2). 9. The wound rotor according to claim 5, characterized in that, a special-shaped reinforcing support frame (4) is also arranged in the rotor connection wire fixing frame (3). 10. A wind power generator, characterized by comprising the wound rotor according to any one of claims 5-9.

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