Stator base for reducing temperature difference of stators of high-altitude long-iron-core permanent magnet wind power motor

Abstract

The invention discloses a stator base for reducing the temperature difference of a high-altitude long-iron-core permanent magnet wind power motor stator, and relates to the technical field of permanent magnet direct-drive wind power motors, a cavity is defined by a first annular plate, a third annular plate, a fourth annular plate and a fifth annular plate, the cavity is divided into a left cavity and a right cavity by a second annular plate, and a plurality of axial rib plates are arranged in the cavity at intervals; the cavity is divided into a plurality of axial cavities by the axial rib plates, the axial cavities are evenly distributed along the circumference of the stator base, the second annular plate is provided with a ventilation hole channel which enables the left axial cavity and the right axial cavity to be communicated to form a longer axial cavity in the axial direction, the adjacent longer axial cavities in the axial direction are an air inlet cavity and an air outlet cavity respectively, the air inlet cavity is communicated with an external air inlet space, and the air outlet cavity is communicated with an external air outlet space. And the air outlet cavity is communicated with the external air outlet space, so that the difference of the air volume of the ventilating duct of the stator iron core can be reduced, each iron core section and a stator coil at each iron core section can be cooled by more sufficient air, and the cooling effect is improved.

Description

Technical Field

[0001] The invention relates to the technical field of permanent magnet direct-drive wind turbine motors, and in particular to a stator base for reducing the temperature difference of a stator of a long-core permanent magnet wind turbine motor at high altitude. Background Art

[0002] The speed of low-speed permanent magnet wind turbine motor is low, only about 10r / min, and the pressure generated by the rotating parts is only a few Pa, which cannot drive the air to flow inside the motor to remove the loss of motor operation. Generally, a special fan is used as the main pressure source for air flow. For large-capacity permanent magnet low-speed wind turbine motors, the iron core is longer, and the iron core radial ventilation method is adopted. After the cooling air passes through the stator, it enters the air gap and diffuses to both ends of the iron core. Finally, it passes through the stator winding end and the ventilation duct. The iron core is longer, and the ventilation path for the part that directly cools the stator is long. In addition, due to structural limitations, it is generally impossible to evenly arrange the fan around the base. As a result, due to the uneven circumferential temperature distribution of the stator coil and the iron core, the circumferential temperature difference can reach 30K-40K, which makes it difficult to further increase the electromagnetic load and affects the economic efficiency of the motor.

[0003] For example, in the Chinese patent, the authorization announcement number is CN110429747B, the authorization announcement date is November 20, 2020, and the name is a method for reducing the circumferential temperature difference between the motor coil and the core. In this method, cooling air enters the large cavity from the air inlet duct below. The cooling air enters the air gap from the large cavity and cools the end of the stator core at the same time. The cooling air enters the air gap for turbulence and enters the stator ventilation groove for heat exchange. However, the stator core is relatively long. During the journey of the cooling air flowing from the air gap at one end of the stator to the other end, the temperature of the cooling air is affected by the heat dissipated by the stator core, stator coil, and rotor magnetic steel. Therefore, the longer the stroke, the higher the temperature of the cooling air flowing to the stator ventilation groove, resulting in uneven cooling of each section of the stator core and low cooling efficiency; the cooling air enters the air inlet cavity from the large cavity. Due to the small radial size of the air inlet cavity, the wind resistance is large, and less cooling air enters. On the one hand, the direct contact time with the stator core is short, the time for heat exchange is short, and the heat exchange efficiency is low. On the other hand, when the cooling air flows from one end of the air inlet cavity to the other end, it is affected by the heat dissipated by the stator core and the stator coil, and the cooling air temperature gradually rises, resulting in uneven cooling of each section of the stator core and low cooling efficiency.

[0004] Especially for large-capacity permanent magnet low-speed wind turbines at high altitudes, cooling is more difficult due to the low air density, further limiting the increase in the electromagnetic load of the motor. Summary of the invention

[0005] In order to solve the deficiencies of the above-mentioned prior art, the present invention constructs a cooling passage for a wind turbine motor through a stator base that reduces the temperature difference of the stator of a long-core permanent magnet wind turbine motor at high altitudes, cools the stator core and the stator coil, and each section of the stator core and the stator coil at each section of the stator core obtain more sufficient cooling air, thereby improving the cooling effect, reducing the stator temperature difference, and improving the cooling air utilization efficiency, thereby adapting to the unfavorable conditions of lower air density in high altitude areas.

[0006] The present invention is achieved through the following technical solutions: A stator base for reducing the temperature difference of a stator of a long iron core permanent magnet wind power motor at high altitude, characterized in that: it comprises a central flange connected to a fixed shaft, a second ring plate is fixed on the central flange, a first ring plate is arranged on one side of the second ring plate, a third ring plate is arranged on the other side of the second ring plate, a fourth ring plate is arranged between the first ring plate and the second ring plate, one end of the fourth ring plate is connected to the first ring plate, and the other end is connected to the second ring plate; a fifth ring plate and a sixth ring plate are arranged in sequence between the second ring plate and the third ring plate, and the fifth ring plate and the sixth ring plate are respectively connected to the second ring plate and the third ring plate Connection; a cavity is surrounded by a first ring plate, a third ring plate, a fourth ring plate and a fifth ring plate, the second ring plate divides the cavity into two left and right chambers, a plurality of axial ribs are arranged at intervals in the chamber, the axial ribs divide the chamber into a plurality of axial cavities, the axial cavities are evenly distributed along the circumference of the stator base, a ventilation duct is arranged on the second ring plate to connect the left and right axial cavities to form an axially longer axial cavity, the adjacent axially longer axial cavities are respectively an air inlet cavity and an air outlet cavity, the air inlet cavity is connected to the external air inlet space, and the air outlet cavity is connected to the external air outlet space.

[0007] Furthermore, the first ring plate is provided with first ventilation channels at intervals along the circumference for connecting the air outlet cavity to the external air outlet space; the third ring plate is provided with second ventilation channels at intervals along the circumference for connecting the air inlet cavity to the external air inlet space.

[0008] Furthermore, the number of the first ventilation channels arranged on the first ring plate is the same as the number of the second ventilation channels arranged on the third ring plate.

[0009] Further, the projections of the first ventilation holes and the second ventilation holes on the circumference are alternate.

[0010] Furthermore, the radial dimensions of the air inlet cavity and the air outlet cavity are not less than 100 mm, which reduces wind friction loss at the air cavity position and ensures ventilation air volume.

[0011] Furthermore, the axial lengths of the air inlet cavity and the air outlet cavity are equal to the total length of the stator core and are set to be more than 1500 mm.

[0012] Furthermore, the outer circle of the outer end surface of the third ring plate serves as an installation space for the copper ring at the end of the wind turbine generator.

[0013] Furthermore, it also includes a seventh ring plate, an eighth ring plate and an outlet box body; the seventh ring plate is vertically connected to the third ring plate, the eighth ring plate is connected to the seventh ring plate, and the outlet box body is arranged below the seventh ring plate to form a wind turbine stator lead-out device structure.

[0014] Furthermore, annular grooves are processed on the inner end surface and the outer circumference of the outer end surface of the eighth ring plate for installing a sealing structure in the subsequent assembly of the wind turbine.

[0015] Furthermore, the first ring plate, the second ring plate, the third ring plate, the fourth ring plate, the fifth ring plate, the sixth ring plate, the seventh ring plate and the eighth ring plate are welded by carbon steel plates.

[0016] The working principle of the present invention is as follows: A stator base for reducing the temperature difference of the stator of a long-core permanent magnet wind turbine at high altitude is installed on the back of the inner diameter side of the stator core in the wind turbine, and cooling air cools the non-driving end and the copper ring of the stator coil in the external air inlet space, and at the same time, the cooling air enters the air inlet cavity through the second ventilation hole on the third ring plate, and the cooling air then flows to the air gap through the radial ventilation holes distributed on the corresponding circumference of the air inlet cavity, and the cooling air flows from the air gap to the air outlet cavity through the radial ventilation holes distributed on the corresponding circumference of the air outlet cavity, and flows to the external air outlet space through the first ventilation hole to cool the driving end of the stator coil; through the action of the corresponding air inlet cavity and the air outlet cavity at the back of the inner diameter of the stator core, the wind speed passing through the corresponding radial ventilation hole is evenly distributed in the axial direction, and the difference in the air volume of the radial ventilation hole is reduced, so that each section of the stator core and the stator coil at each section of the stator core can obtain sufficient and uniform cooling air, thereby improving the cooling effect.

[0017] The beneficial effects of the present invention are as follows: 1. Compared with the method in which cooling air enters from the air gap and then cools through the radial ventilation duct, the difference in air volume of the radial ventilation duct of the stator core can be reduced, so that each core segment and the stator coil at each core segment can obtain more sufficient air cooling, thereby improving the cooling effect.

[0018] 2. The air inlet cavity and the air outlet cavity of the machine base of the present invention are distributed in a circle, which provides favorable conditions for the uniform distribution of subsequent air inlets and outlets, makes the cooling air more uniform on the circle, and helps to ensure the ventilation and cooling effect.

[0019] 3. The outer circle of the outer end surface of the third ring plate can be used as the installation space for the copper ring at the end of the wind turbine generator. When ventilation cooling is performed, the copper ring can be directly cooled.

[0020] 4. Annular grooves are processed on the inner end face and the outer circle of the outer end face of the eighth ring plate for installing the sealing structure in the subsequent assembly of the wind turbine. The sealing structure completes the sealing of the dynamic and static separation of the rotor and the stator. The cooling air will not be lost from the dynamic and static separation, ensuring the utilization rate of the cooling air, and there is more sufficient cooling air to directly cool the non-driving end of the stator coil. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Longitudinal section of stator frame; Figure 2 AA cross-section of stator frame; Figure 3 Cross-section of stator frame BB; Figure 4 Cross-section of stator frame CC; Figure 5 Schematic diagram of the stator frame.

[0022] Figure markings: 1-center flange, 2-second ventilation channel, 3-ventilation channel, 4-first ventilation channel, 5-seventh ring plate, 6-eighth ring plate, 7-outlet box body, 8-sixth ring plate, 9-first ring plate, 10-second ring plate, 11-third ring plate, 12-axial rib plate, 13-fourth ring plate, 14-fifth ring plate, 15-external air outlet space, 16-external air inlet space, 17-air inlet cavity, 18-air outlet cavity. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example 1

[0024] like Figure 1-Figure 5As shown, a stator base for reducing the temperature difference of a stator of a long-core permanent magnet wind turbine at high altitude comprises a center flange 1 connected to a stator shaft, a second ring plate 10 is fixed on the center flange 1, a first ring plate 9 is arranged on one side of the second ring plate 10, a third ring plate 11 is arranged on the other side of the second ring plate 10, a fourth ring plate 13 is arranged between the first ring plate 9 and the second ring plate 10, one end of the fourth ring plate 13 is connected to the first ring plate 9, and the other end is connected to the second ring plate 10; a fifth ring plate 14 and a sixth ring plate 8 are arranged in sequence from top to bottom between the second ring plate 10 and the third ring plate 11, and the fifth ring plate 14 and the sixth ring plate 8 are respectively connected to the second ring plate 10 and the third ring plate 11. 11 is connected; a cavity is surrounded by a first ring plate 9, a third ring plate 11, a fourth ring plate 13 and a fifth ring plate 14, the second ring plate 10 divides the cavity into two left and right chambers, a plurality of axial ribs 12 are arranged at intervals in the chamber, the axial ribs 12 divide the chamber into a plurality of axial cavities, and the axial cavities are evenly distributed along the circumference of the stator base, a ventilation duct 3 is arranged on the second ring plate 10 to connect the left and right axial cavities to form an axially longer axial cavity, and adjacent axially longer axial cavities are respectively an air inlet cavity 17 and an air outlet cavity 18, the air inlet cavity 17 is connected to the external air inlet space 16, and the air outlet cavity 18 is connected to the external air outlet space 15.

[0025] Furthermore, the first ring plate 9 is provided with first ventilation channels 4 at intervals along the circumference for connecting the air outlet cavity 18 to the external air outlet space 15 ; the third ring plate 11 is provided with second ventilation channels 2 at intervals along the circumference for connecting the air inlet cavity 17 to the external air inlet space 16 .

[0026] Furthermore, the number of the first ventilation channels 4 provided on the first ring plate 9 is the same as the number of the second ventilation channels 2 provided on the third ring plate 11 .

[0027] Furthermore, the projections of the first ventilation holes 4 and the second ventilation holes 2 on the circumference are alternate.

[0028] In this embodiment, the first ventilation duct 4 and the second ventilation duct 2 are arranged at intervals along the circumference on the first ring plate 9 and the third ring plate 11, respectively, so that half of the axial cavity connected in the axial direction is the air inlet cavity 17, and the other half is the air outlet cavity 18. The air outlet cavity 18 is connected to the external air outlet space 15 through the first ventilation duct 4, and the air inlet cavity 17 is connected to the external air inlet space 16 through the second ventilation duct 2. Since the air inlet cavity 17 is distributed on the circumference, after the cooling air enters the air inlet cavity 17, the air volume is evenly distributed on the circumference, and uneven air volume distribution will not be caused, resulting in uneven cooling. Example 2

[0029] This embodiment further elaborates and supplements the implementation mode of the present invention on the basis of Embodiment 1.

[0030] The axial lengths of the air inlet cavity 17 and the air outlet cavity 18 are equal to the total length of the stator core and are set to be more than 1500 mm.

[0031] The outer circle of the outer end surface of the third ring plate 11 serves as the installation space for the copper ring at the end of the wind turbine. The stator frame constructs a cooling passage for the wind turbine, which ensures sufficient cooling of the copper ring at the end.

[0032] It also includes a seventh ring plate 5, an eighth ring plate 6 and an outlet box body 7; the seventh ring plate 5 is vertically connected to the third ring plate 11, the eighth ring plate 6 is connected to the seventh ring plate 5, and the outlet box body 7 is arranged below the seventh ring plate 5 to form a wind turbine stator lead-out device structure.

[0033] Annular grooves are processed on the inner end surface and the outer circumference of the outer end surface of the eighth ring plate 6 for installing the sealing structure in the subsequent assembly of the wind turbine.

[0034] The first ring plate 9 , the second ring plate 10 , the third ring plate 11 , the fourth ring plate 13 , the fifth ring plate 14 , the sixth ring plate 8 , the seventh ring plate 5 , and the eighth ring plate 6 are welded by using carbon steel plates. Example 3

[0035] This embodiment further elaborates and supplements the implementation mode of the present invention on the basis of Embodiment 1 or Embodiment 2.

[0036] After a stator frame for reducing the temperature difference of a high-altitude long-core permanent magnet wind turbine stator is assembled with a wind turbine, cooling air cools the non-driving end and the copper ring of the stator coil in the external air inlet space 16. At the same time, the cooling air enters the air inlet cavity 17 from the second ventilation duct 2, flows to the radial ventilation ducts distributed on the circumference of the stator core corresponding to the air inlet cavity 17, then flows to the air gap, and flows from the air gap to the air outlet cavity 18 corresponding to the radial ventilation ducts distributed on the circumference of the stator core, enters the air outlet cavity 18, and flows from the first ventilation duct 4 to the external air outlet space 15 to cool the stator coil. The driving end of the coil is cooled; the circulating cooling air takes away the heat generated in the middle of the stator coil, the heat generated by the stator core and the heat generated by the rotor magnet, and the radial dimensions of the air inlet cavity 17 and the air outlet cavity 18 are large, and the wind resistance is reduced when the cooling air enters the air inlet cavity 17, and the cooling air entering the air inlet cavity 17 will increase, so that the contact area between the cooling air and the stator is large enough, the heat exchange is sufficient and the effect is high, so that each section of the stator core and the stator coil at each section of the stator core can obtain more sufficient cooling air, thereby improving the cooling effect and having a significant temperature reduction effect.

[0037] In this embodiment, the radial dimensions of the air inlet cavity 17 and the air outlet cavity 18 are not less than 100 mm, which reduces wind resistance and ensures ventilation air volume.

[0038] The present invention improves the cooling effect, reduces the stator temperature difference, and improves the utilization efficiency of cooling air, thereby adapting to the unfavorable conditions of lower air density in high-altitude areas. The present invention has a simple structure and is easy to implement.

[0039] Even if the air outlet pipe in the prior art with the authorization announcement number CN110429747B and the authorization announcement date of November 20, 2020, and the name of a method for reducing the circumferential temperature difference between a motor coil and an iron core, is used as the air inlet, the air enters from the air outlet pipe, the cooling air enters the air outlet cavity, flows to the stator ventilation groove corresponding to the air outlet cavity, and is released from the stator after the air is discharged from the air gap. In this process, due to the small radial size of the air outlet cavity and the large wind resistance, less cooling air enters the air outlet cavity, which will cause the cooling air to contact the stator iron core. The area is reduced, and the heat exchange efficiency is low; when the cooling air flows from one end of the air outlet cavity to the other end of the air outlet cavity, the temperature of the cooling air gradually increases due to the heat dissipated by the stator core and the stator coil, and the cooling air with a higher temperature flows to the stator ventilation groove, resulting in uneven cooling of each section of the stator core and low cooling efficiency; the cooling air flows from the stator ventilation groove to the air gap, and then flows from the air gap to the two ends of the stator and is released from the stator. Since the cooling air has exchanged heat with the stator core, it flows from the air gap to the two ends of the stator for cooling, and the cooling effect is low. Compared with the present invention, it is also difficult to achieve the cooling effect of the present invention by using the air outlet pipe in the prior art as the air inlet.

Claims

1. A stator frame for reducing the temperature difference of a long-core permanent magnet wind turbine stator at high altitude, characterized in that: The invention comprises a central flange (1) connected to a fixed shaft, a second ring plate (10) being fixed to the central flange (1), a first ring plate (9) being arranged on one side of the second ring plate (10), a third ring plate (11) being arranged on the other side of the second ring plate (10), a fourth ring plate (13) being arranged between the first ring plate (9) and the second ring plate (10), one end of the fourth ring plate (13) being connected to the first ring plate (9), and the other end being connected to the second ring plate (10); a fifth ring plate (14) and a sixth ring plate (8) being arranged in sequence between the second ring plate (10) and the third ring plate (11), the fifth ring plate (14) and the sixth ring plate (8) being connected to the second ring plate (10) and the third ring plate (11) respectively; and the first ring plate (13) and the second ring plate (10) being arranged on the first ring plate (9). The plate (9), the third ring plate (11), the fourth ring plate (13) and the fifth ring plate (14) form a cavity, the second ring plate (10) divides the cavity into two left and right chambers, a plurality of axial rib plates (12) are arranged at intervals in the chamber, the axial rib plates (12) divide the chamber into a plurality of axial cavities, the axial cavities are evenly distributed along the circumference of the stator base, the second ring plate (10) is provided with a ventilation duct (3) to connect the two left and right axial cavities to form an axially longer axial cavity, the adjacent axially longer axial cavities are respectively an air inlet cavity (17) and an air outlet cavity (18), the air inlet cavity (17) is connected to an external air inlet space (16), and the air outlet cavity (18) is connected to an external air outlet space (15).

2. A stator base for reducing the temperature difference of a high-altitude long-core permanent magnet wind turbine stator as claimed in claim 1, characterized in that: The first ring plate (9) is provided with first ventilation channels (4) at intervals along the circumference for connecting the air outlet cavity (18) to an external air outlet space (15); and the third ring plate (11) is provided with second ventilation channels (2) at intervals along the circumference for connecting the air inlet cavity (17) to an external air inlet space (16).

3. A stator base for reducing the temperature difference of a high-altitude long-core permanent magnet wind turbine stator as claimed in claim 2, characterized in that: The number of the first ventilation channels (4) provided on the first ring plate (9) is the same as the number of the second ventilation channels (2) provided on the third ring plate (11).

4. A stator base for reducing the temperature difference of a stator of a long-core permanent magnet wind turbine at high altitude as claimed in claim 2 or 3, characterized in that: The projections of the first ventilation holes (4) and the second ventilation holes (2) on the circumference are alternating.

5. A stator base for reducing the temperature difference of a stator of a long-core permanent magnet wind turbine at high altitude as claimed in claim 2 or 3, characterized in that: The radial dimensions of the air inlet cavity (17) and the air outlet cavity (18) are not less than 100 millimeters.

6. A stator base for reducing the temperature difference of a stator of a long-core permanent magnet wind turbine at high altitude as claimed in claim 2 or 3, characterized in that: The axial lengths of the air inlet cavity (17) and the air outlet cavity (18) are equal to the total length of the stator core.

7. A stator base for reducing the temperature difference of a stator of a long-core permanent magnet wind turbine at high altitude as claimed in claim 2, characterized in that: The outer circumference of the outer end surface of the third ring plate (11) serves as a mounting space for the copper ring at the end of the wind turbine generator.

8. A stator base for reducing the temperature difference of a stator of a long-core permanent magnet wind turbine at high altitude as claimed in claim 7, characterized in that: It also comprises a seventh ring plate (5), an eighth ring plate (6) and an outlet box body (7); the seventh ring plate (5) is vertically connected to the third ring plate (11), the eighth ring plate (6) is connected to the seventh ring plate (5), and the outlet box body (7) is arranged below the seventh ring plate (5), forming a wind turbine stator lead-out device structure.

9. A stator base for reducing the temperature difference of a stator of a long-core permanent magnet wind turbine at high altitude as claimed in claim 8, characterized in that: The inner end surface and the outer end surface of the eighth ring plate (6) are both machined with annular grooves at their outer circumference for installing a sealing structure in the subsequent assembly of the wind turbine.

10. A stator base for reducing the temperature difference of a stator of a long-core permanent magnet wind turbine at high altitude according to claim 8 or 9, characterized in that: The first ring plate (9), the second ring plate (10), the third ring plate (11), the fourth ring plate (13), the fifth ring plate (14), the sixth ring plate (8), the seventh ring plate (5), and the eighth ring plate (6) are welded using carbon steel plates.

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