Rotor ventilation structure of axial flow cooling system of permanent magnet direct-driven wind driven generator

Abstract

The invention provides a rotor ventilation structure of an axial flow cooling system of a permanent magnet direct-driven wind driven generator, which is characterized in that ventilation holes and ventilation heat dissipation paths which are axially through are arranged on one side of a box body, eddy current loss is reduced, effective heat dissipation is performed on a permanent magnet, and the heat dissipation rate of the ventilation system is improved. The perforated radiating fins and the axial grooves are additionally arranged on the box body, so that the rotating effect of the generator can be fully utilized, the contact area is increased, gas is fully contacted with the box body, the ventilation and radiating efficiency is improved, and the temperature of the permanent magnet is effectively reduced. In addition, the axial hollow holes arranged on one side of the box body and the radiating fins arranged outside the box body can independently act and improve the radiating performance, and can also be arranged on the box body at the same time, so that the eddy current loss is reduced while the radiating area is increased.

Description

Technical Field

[0001] The invention relates to the technical field of generators, and in particular to a rotor ventilation structure of an axial flow cooling system of a permanent magnet direct-drive wind generator. Background Art

[0002] As the capacity of permanent magnet direct-drive wind turbines continues to increase, the electromagnetic load and thermal load are also increasing. The generator generates a large amount of heat, which requires a suitable ventilation and cooling system to take away the heat to avoid excessive temperature of the generator structure, causing serious accidents such as overheating and burning of the generator.

[0003] At present, there are many cooling systems for permanent magnet direct-drive wind turbines. If you are more concerned about the temperature of the permanent magnets in the rotor of the generator and need to effectively suppress the temperature rise of the permanent magnets, you can choose the cooling structure of the outer rotor; generally speaking, in order to fully dissipate the heat of the motor, the generator stator will adopt a radially symmetrical wind path structure, and some will also be combined with an axial cooling structure. The principle of the stator radially symmetrical cooling structure is that this structure uses the rotation effect of the rotor to introduce cooling air into the rotor rotating body, and throws the wind out from one end and enters the generator rotor bracket, and enters the outer cavity area of ​​the bracket through the ventilation holes on the inner and outer cavities of the rotor bracket. Subsequently, the cooling air enters the stator end area of ​​the generator air inlet area from the outer cavity area of ​​the bracket, and is divided into two paths here, one directly enters the generator axial ventilation duct; the other cools the stator end winding and enters the generator axial ventilation duct through the gap between the stator end windings of the generator.

[0004] Although the radially symmetrical cooling structure of the stator is currently widely used and has a certain cooling and heat dissipation effect, from the perspective of wind path analysis, the wind turbine using this cooling structure has serious uneven hot and cold cores at the ends of the rotor and stator, which can easily cause excessive local thermal stress and thermal deformation of the magnetic steel box. In addition, due to the high cost of large wind turbines, once a certain thermal failure occurs and causes the wind farm to shut down, it will cause huge losses. Therefore, improving the ventilation structure of the rotor system and improving the heat dissipation capacity of the wind turbine cooling system are crucial to the continuous development of wind power equipment and the continuous development of offshore wind energy. Summary of the invention

[0005] The object of the present invention is to provide a permanent magnet direct-drive wind generator axial flow cooling system rotor ventilation structure, a permanent magnet direct-drive wind generator rotor and a permanent magnet direct-drive wind generator, which improve the heat dissipation effect of the magnetic steel box and the rotor core component, extend the insulation life, and ensure the safe operation of the motor, so as to solve at least one technical problem existing in the above-mentioned background technology.

[0006] In order to achieve the above object, the present invention adopts the following technical scheme.

[0007] A rotor ventilation structure of an axial flow cooling system of a permanent magnet direct-drive wind turbine generator comprises a box body; the box body is tightly fitted on the rotor of the generator; the box body has a permanent magnet; the box body also has a ventilation hole, the ventilation hole starts from the hot end of the box body, extends along the axial direction of the box body, and the ventilation hole is located above the permanent magnet.

[0008] Preferably, the top of the box body has one or more groups of open-hole heat dissipation fins; each group of open-hole heat dissipation fins includes a plurality of fins arranged radially and spaced apart along the box body, each of the fins is extended axially along the box body, and each of the fins also has one or more rectangular through holes.

[0009] Preferably, the top of the box body has one or more groove groups; each groove group includes a plurality of concave grooves spaced apart along the radial direction of the box body, and each of the concave grooves extends along the axial direction of the box body.

[0010] Preferably, the box body is a two-section structure, comprising a hot end side portion and a cold end side portion which are spaced apart along the axial direction of the rotor of the generator, and the ventilation hole is located at the hot end side portion and passes through the hot end side portion.

[0011] Preferably, the top of the hot end side has one or more groups of open-hole heat dissipation fins; each group of the open-hole heat dissipation fins includes a plurality of fins radially arranged at intervals along the hot end side, each of the fins is axially extended along the hot end side, and each of the fins also has one or more rectangular through holes.

[0012] Preferably, the top of the hot end side has one or more groove groups; each groove group includes a plurality of concave grooves radially spaced apart along the hot end side, and each of the concave grooves is axially extended along the hot end side.

[0013] Preferably, the box body is a magnetic steel box; and the ventilation holes are rectangular slots.

[0014] In a second aspect, the present invention provides a rotor of an axial flow cooling system of a permanent magnet direct-drive wind turbine generator, comprising a plurality of the above-mentioned rotor ventilation structures disposed on the rotor, wherein the plurality of rotor ventilation structures are arranged at intervals along the circumference of the rotor.

[0015] In a third aspect, the present invention provides a permanent magnet direct-drive wind turbine having the above-mentioned rotor.

[0016] It can be seen from the technical solutions provided by the above-mentioned embodiments of the present invention that the present invention provides a rotor ventilation structure of an axial cooling system of a permanent magnet direct-drive wind turbine, wherein the rotor ventilation structure proposes to open a ventilation hole that penetrates along the axial direction on one side of the box body, a ventilation and heat dissipation path, and at the same time reduce eddy current loss, effectively dissipate heat for the permanent magnet, and improve the heat dissipation rate of the ventilation system. The addition of perforated heat dissipation fins and axial grooves on the box body can make full use of the rotation of the generator, increase the contact area, allow the gas to fully contact the box body, improve the ventilation and heat dissipation efficiency, and effectively reduce the temperature of the permanent magnet. In addition, the axial hollow holes set on one side of the box body and the heat sink set on the outside can act alone to improve the heat dissipation performance, and can also be set on the box body at the same time to increase the heat dissipation area while reducing eddy current loss.

[0017] Additional aspects and advantages of the present invention will be given in part in the following description, which will become obvious from the following description, or may be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0019] Figure 1 A three-dimensional structural diagram, a cross-sectional diagram and a partial cutaway diagram of a rotor ventilation structure of an axial flow cooling system of a permanent magnet direct-drive wind turbine generator with axial ventilation holes provided by the present invention.

[0020] Figure 2 A three-dimensional structural diagram and a cross-sectional diagram of a rotor ventilation structure of an axial flow cooling system of a permanent magnet direct-drive wind turbine generator with segmented axial ventilation holes provided by the present invention.

[0021] Figure 3 A three-dimensional structural diagram and a cross-sectional diagram of a rotor ventilation structure of an axial flow cooling system of a permanent magnet direct-drive wind turbine generator with open-hole heat dissipation fins provided by the present invention.

[0022] Figure 4 A three-dimensional structural diagram and a cross-sectional diagram of a rotor ventilation structure of an axial flow cooling system of a permanent magnet direct-drive wind turbine generator with axial concave grooves provided by the present invention.

[0023] In the figure:

[0024] 1. Box body 11. Hot end side 12. Cold end side 13. Air outlet slot 2. Ventilation hole 3. Heat dissipation fin 4. Concave slot 5. Rotor 6. Permanent magnet. DETAILED DESCRIPTION

[0025] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be interpreted as limiting the present invention.

[0026] It will be understood by those skilled in the art that, unless expressly stated, the singular forms "one", "said", and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present invention refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It should be understood that when we refer to an element as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be intermediate elements. In addition, the "connection" or "coupling" used herein may include wireless connection or coupling. The term "and / or" used herein includes any unit and all combinations of one or more associated listed items.

[0027] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those generally understood by those skilled in the art in the art to which the present invention belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as herein.

[0028] To facilitate understanding of the embodiments of the present invention, several specific embodiments will be further explained below with reference to the accompanying drawings, and each embodiment does not constitute a limitation on the embodiments of the present invention.

[0029] See also Figures 1 to 4 The present invention provides a rotor ventilation structure of an axial flow cooling system of a permanent magnet direct-drive wind turbine generator, comprising a box body. The box body is tightly fitted on the rotor of the generator. In some preferred embodiments, the box body adopts a magnetic steel box. The permanent magnet is accommodated in the box body. The box body also has a ventilation hole, which starts from the hot end of the box body and is arranged along the axial direction of the box body, and the ventilation hole is located above the permanent magnet.

[0030] The rotor ventilation structure provided by the present invention increases the ventilation and heat dissipation path, while reducing eddy current loss, effectively dissipating the heat of the permanent magnet, and improving the heat dissipation rate of the ventilation system.

[0031] In the preferred embodiment provided by the present invention, in order to further improve the ventilation and heat dissipation effect, the top of the box body is provided with one or more groups of open-hole heat dissipating fins; each group of open-hole heat dissipating fins includes a plurality of fins arranged at intervals along the radial direction of the box body, each fin is extended along the axial direction of the box body, and each fin also has one or more rectangular through holes, so as to increase the heat dissipation area of ​​the box body surface and improve the heat dissipation coefficient while ensuring that the gas resistance is not greatly affected.

[0032] In some other embodiments, the top of the box body has one or more groove groups; each groove group includes a plurality of concave grooves arranged at intervals along the radial direction of the box body, and each concave groove is extended along the axial direction of the box body.

[0033] In the above embodiment, the ventilation hole is integrally provided through the box body, that is, the air inlet and the air outlet of the ventilation hole are respectively located at the axial ends of the box body.

[0034] In some other preferred embodiments, the box body is a two-section structure, including a hot end side portion and a cold end side portion arranged at intervals along the axial direction of the rotor of the generator, the ventilation hole is located at the hot end side portion and penetrates the hot end side portion, and the interval between the hot end side portion and the cold end side portion is configured as an air outlet slot.

[0035] In these embodiments, the perforated heat dissipating fins and the groove group are both located at the hot end side, and the specific arrangement is as follows:

[0036] The top of the hot end side has one or more groups of open hole heat dissipation fins; each group of open hole heat dissipation fins includes multiple fins arranged radially and spaced along the hot end side, each fin is arranged along the axial direction of the hot end side, and each fin also has one or more rectangular through holes. When the open hole heat dissipation fins are a group, the length of each fin is equal to the length of the hot end side. When the hot end side has multiple groups, the multiple groups of open hole heat dissipation fins are arranged in sequence and spaced along the axial direction of the hot end side.

[0037] In other embodiments, the top of the hot end side has one or more groove groups; each groove group includes a plurality of concave grooves arranged radially and spaced apart along the hot end side, and each concave groove is arranged axially through the hot end side. Figure 4 As shown, two groups of groove groups are arranged on the top of the hot end side, and the two groups of groove groups are arranged with spacing from each other along the radial direction of the hot end side, and the spacing between the two groups of groove groups is greater than the spacing of the concave grooves in each group of groove groups.

[0038] The rotor ventilation structure provided above can reduce eddy current loss, increase air flow, enlarge contact area and reduce permanent magnet temperature while reducing material usage and reducing costs.

[0039] In a second aspect, the present invention provides a rotor of an axial flow cooling system of a permanent magnet direct-drive wind turbine generator, comprising a plurality of the above-mentioned rotor ventilation structures disposed on the rotor, wherein the plurality of rotor ventilation structures are spaced apart along the circumference of the rotor.

[0040] In a third aspect, the present invention also provides a permanent magnet direct-drive wind turbine generator having the above-mentioned rotor.

[0041] In summary, the present invention provides a rotor ventilation structure of an axial cooling system of a permanent magnet direct-drive wind turbine, wherein the rotor ventilation structure proposes to open a ventilation hole that penetrates along the axial direction on one side of the box body, a ventilation and heat dissipation path, and reduce eddy current loss at the same time, effectively dissipate heat for the permanent magnet, and improve the heat dissipation rate of the ventilation system. The addition of perforated heat dissipation fins and axial grooves on the box body can make full use of the rotation of the generator, increase the contact area, allow the gas to fully contact the box body, improve the ventilation and heat dissipation efficiency, and effectively reduce the temperature of the permanent magnet. In addition, the axial hollow holes set on one side of the box body and the heat sink set on the outside can act alone and improve the heat dissipation performance, or they can be set on the box body at the same time to increase the heat dissipation area while reducing eddy current loss.

[0042] Those skilled in the art can understand that the accompanying drawings are only schematic diagrams of an embodiment, and the modules or processes in the accompanying drawings are not necessarily required to implement the present invention.

[0043] It can be known from the description of the above implementation methods that those skilled in the art can clearly understand that the present invention can be implemented by means of software plus a necessary general hardware platform. Based on such an understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which can be stored in a storage medium such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in the various embodiments of the present invention or certain parts of the embodiments.

[0044] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device or system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. The device and system embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0045] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A rotor ventilation structure of an axial flow cooling system of a permanent magnet direct-drive wind turbine generator, characterized in that: It comprises a box body; the box body is tightly fitted on the rotor of the generator; the box body has a permanent magnet; the box body also has a ventilation hole, the ventilation hole starts from the hot end of the box body, extends along the axial direction of the box body, and the ventilation hole is located above the permanent magnet.

2. The rotor ventilation structure according to claim 1, characterized in that: The top of the box body is provided with one or more groups of open-hole heat dissipation fins; each group of open-hole heat dissipation fins includes a plurality of fins arranged at intervals along the radial direction of the box body, each of the fins is extended along the axial direction of the box body, and each of the fins also has one or more rectangular through holes.

3. The rotor ventilation structure according to claim 1, characterized in that: The top of the box body is provided with one or more groove groups; each groove group includes a plurality of concave grooves arranged at intervals along the radial direction of the box body, and each of the concave grooves is extended along the axial direction of the box body.

4. The rotor ventilation structure according to claim 1, characterized in that: The box body is a two-section structure, comprising a hot end side portion and a cold end side portion which are spaced apart along the axial direction of the rotor of the generator, and the ventilation hole is located at the hot end side portion and passes through the hot end side portion.

5. The rotor ventilation structure according to claim 4, characterized in that: The top of the hot end side has one or more groups of open hole heat dissipation fins; each group of open hole heat dissipation fins includes multiple fins radially arranged along the hot end side, each fin is axially extended along the hot end side, and each fin also has one or more rectangular through holes.

6. The rotor ventilation structure according to claim 4, characterized in that: The top of the hot end side portion is provided with one or more groove groups; each groove group includes a plurality of concave grooves arranged at intervals along the radial direction of the hot end side portion, and each of the concave grooves is extended axially along the hot end side portion.

7. The rotor ventilation structure according to any one of claims 1 to 6, characterized in that: The box body is a magnetic steel box; the ventilation holes are rectangular slots.

8. The rotor of the axial flow cooling system of a permanent magnet direct-drive wind turbine generator is characterized in that: The invention comprises a plurality of rotor ventilation structures as claimed in any one of claims 1 to 7 which are arranged on the rotor, and the plurality of rotor ventilation structures are arranged at intervals along the circumferential direction of the rotor.

9. A permanent magnet direct-drive wind turbine generator, characterized in that: A rotor as claimed in claim 8 is provided.

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