Zoned cooling method for stator of high-altitude long-core wind turbine generator

Abstract

The present invention relates to the technical field of ventilation and cooling of permanent magnet direct-drive wind turbine generators. Disclosed is a zoned cooling method for a stator of a high-altitude long-core wind turbine generator. Among cooling air paths in the present invention, one path of air cools the part of a stator close to a non-drive end, another path of air cools the part of the stator close to a drive end, and a third path of air cools the middle portion of the stator by means of circumferential flow in an air gap. Each segment of stator core and a stator coil located at each segment of stator core receive sufficient and uniform cooling air, thereby improving a cooling effect, reducing the temperature difference of the stator, and improving the utilization efficiency of the cooling air.

Description

A method for zoned cooling of the stator of a high-altitude long-core wind turbine. Technical Field

[0001] This invention relates to the field of ventilation and cooling technology for permanent magnet direct-drive wind turbines, specifically to a method for stator partitioning cooling of a high-altitude long-core wind turbine, applicable to high-altitude, large-capacity, low-speed permanent magnet wind turbines. Background Technology

[0002] Low-speed permanent magnet wind turbines operate at low speeds, only around 10 r / min. The pressure generated by the rotating parts is only a few Pascals, insufficient to drive airflow within the motor to remove operating losses. A dedicated fan is typically used as the primary pressure source for airflow. However, for larger-capacity low-speed permanent magnet wind turbines with longer cores, radial ventilation is employed. Cooling air passes through the stator, enters the air gap, diffuses to both ends of the core, and finally passes through the stator winding ends and ventilation ducts. Due to the longer core, the ventilation path for directly cooling the stator is long. Furthermore, structural limitations prevent the fans from being evenly distributed around the frame, resulting in uneven temperature distribution around the stator coils and core, with circumferential temperature differences reaching 30K-40K. This makes it difficult to further increase the electromagnetic load, impacting the motor's economic efficiency.

[0003] For example, in a Chinese patent, authorization announcement number CN110429747B, authorization announcement date November 20, 2020, entitled "A Method for Reducing the Circumferential Temperature Difference Between Motor Coils and Core," cooling air enters the large cavity from the lower air inlet duct. Simultaneously, the cooling air enters the air gap from the large cavity, cooling the ends of the stator core. The cooling air enters the air gap and undergoes turbulence before entering the stator ventilation grooves for heat exchange. However, because the stator core is relatively long, the temperature of the cooling air gradually increases during its journey from one end of the stator air gap to the other end due to the heat generated by the stator core, stator coils, and rotor magnets. As the temperature of the air gradually increases, the cooling effect on the stator ends is not significant. Because the longer the stroke, the higher the temperature of the cooling air flowing into the stator ventilation groove, the uneven cooling of each section of the stator core results in low cooling efficiency. The cooling air enters the air inlet cavity from the large cavity. Due to the small radial dimension of the air inlet cavity, the air resistance is large, and less cooling air enters. On the one hand, this results in a short direct contact time with the stator core, a short time for heat exchange, and low heat exchange efficiency. On the other hand, as the cooling air flows from one end of the air inlet cavity to the other end, it is affected by the heat generated by the stator core and stator coils, and the temperature of the cooling air gradually increases, resulting in uneven cooling of each section of the stator core and low cooling efficiency.

[0004] Especially for high-altitude, large-capacity, low-speed permanent magnet wind turbines, the low air density makes cooling more difficult, further limiting the increase of the motor's electromagnetic load. Summary of the Invention

[0005] To address the shortcomings of the existing technology, this invention provides a method for stator partitioning cooling of high-altitude long iron core wind turbines, applicable to high-altitude large-capacity permanent magnet low-speed wind turbines.

[0006] This invention is achieved through the following calculation scheme:

[0007] A method for partitioned cooling of the stator of a high-altitude long iron core wind turbine is characterized in that: after the cooling air enters the first pressure equalization chamber from the first ventilation duct, it is dispersed in the circumferential direction and flows to the radial ventilation ducts distributed on the circumference of the stator iron core corresponding to the first pressure equalization chamber to the air gap, and then enters the fourth space to cool the non-driving end of the stator coil. At the same time, the cooling air flows from the fourth space to the fifth space.

[0008] After the cooling air enters the third equalizing chamber from the second ventilation duct, it also disperses in the circumferential direction and flows to the radial ventilation ducts distributed on the circumference of the stator core in the third equalizing chamber to the air gap, and then enters the sixth space to cool the driving end of the stator coil. At the same time, the cooling air enters the third space from the sixth space and then flows to the fifth space.

[0009] After entering the second equalizing chamber through the third ventilation duct, the cooling air disperses circumferentially into the air inlet chamber, flows to the radial ventilation channels distributed on the circumference of the stator core corresponding to the air inlet chamber, and then flows through the air gap to the radial ventilation channels distributed on the circumference of the first and second air outlet chambers, entering the first and second air outlet chambers. The cooling air in the first air outlet chamber enters the first space, the second space, and the fifth space. The cooling air in the second air outlet chamber flows to the second space and the fifth space. At this point, the three airflows converge in the fifth space and are discharged through the air outlet duct installed in the fifth space.

[0010] A cavity is formed between the stator core and the stator frame. A third ring plate is installed on the stator frame, dividing the cavity into left and right chambers. Multiple axial stiffeners are spaced apart within the cavity, dividing it into multiple axial chambers. These axial chambers are evenly distributed along the circumference of the stator frame. Some of these axial chambers are air inlets, and some are air outlets, arranged adjacent to each other and evenly distributed along the circumference. Ventilation channels are formed on the third ring plate of the air inlet chamber, making it an axially longer air inlet chamber. The air outlet chamber is divided into a first air outlet chamber and a second air outlet chamber by the third ring plate. A fourth space is provided at the non-driving end of the stator coil, and a fifth space is provided below and connected to the fourth space. A first equalizing chamber and a second equalizing chamber are provided between the fifth space and the axial chambers. The equalizing chamber is connected to the air inlet chamber. A third equalizing chamber is arranged adjacent to the drive end of the stator coil in the axial cavity. A first ventilation duct, a second ventilation duct, and a third ventilation duct are installed in the fifth space. The air outlet of the first ventilation duct is located in the first equalizing chamber and is connected to the first equalizing chamber. The air outlet of the second ventilation duct passes through the air inlet chamber and is located in the third equalizing chamber and is connected to the third equalizing chamber. The air outlet of the third ventilation duct is located in the second equalizing chamber and is connected to the second equalizing chamber. A first space and a second space are arranged below the cavity. The first air outlet chamber is connected to the first space, and the second air outlet chamber is connected to the second space. The first space is connected to the second space, and the second space is connected to the fifth space. A sixth space and a third space are installed below the first space and the second space. The sixth space is connected to the third space, and the third space is connected to the fifth space.

[0011] Furthermore, the stator frame includes a first ring plate, a second ring plate, a third ring plate, a fourth ring plate, and a fifth ring plate, and several axial stiffeners arranged sequentially on the back side of the inner diameter of the stator core. A sixth ring plate is arranged between the second and third ring plates, with one end connected to the second ring plate and the other end connected to the third ring plate. A seventh ring plate is arranged between the third and fifth ring plates, with one end connected to the third ring plate and the other end connected to the fifth ring plate. The bottom end of the fourth ring plate is connected to the seventh ring plate. The second, sixth, seventh, and fourth ring plates form a cavity, and the third ring plate divides the cavity into left and right chambers. One chamber is formed by the second, third, and sixth annular plates, and the other chamber is formed by the third, seventh, and fourth annular plates. An inclined conical annular plate connects the first and third annular plates, and the end of the second annular plate is connected to the conical annular plate. The first, second, and conical annular plates form a third pressure equalization chamber. A tenth annular plate is provided between the fourth and fifth annular plates. One end of the tenth annular plate is connected to the fourth annular plate, and the other end is connected to the fifth annular plate. The tenth annular plate is located above the seventh annular plate. The fourth, fifth, seventh, and tenth annular plates form a first and a second pressure equalization chamber through which cooling air passes.

[0012] Furthermore, the fourth ring plate of the second equalizing chamber is provided with first ventilation holes at circumferential intervals to connect the air inlet chamber and the second equalizing chamber; the sixth ring plate is provided with second ventilation holes at circumferential intervals, and the second ventilation holes are only distributed on the sixth ring plate corresponding to the first air outlet chamber, for connecting the first space; the seventh ring plate is provided with third ventilation holes at circumferential intervals, and the third ventilation holes are only distributed on the seventh ring plate corresponding to the second air outlet chamber, for connecting the second space; the second ventilation holes and the third ventilation holes are in the same position on the circumference.

[0013] Furthermore, the sixth ring plate is located above the conical ring plate. The third ring plate, the sixth ring plate, and the conical ring plate form a first space. An eighth ring plate is set below the seventh ring plate. One end of the eighth ring plate is connected to the third ring plate, and the other end is connected to the fifth ring plate. The third ring plate, the fifth ring plate, the seventh ring plate, and the eighth ring plate form a second space. A fourth ventilation hole is set along the circumference of the third ring plate located in the first space and the second space to connect the first space with the second space. A ninth ring plate is set below the eighth ring plate. One end of the ninth ring plate is connected to the third ring plate, and the other end is connected to the fifth ring plate. The third ring plate, the fifth ring plate, the eighth ring plate, and the ninth ring plate form a third space.

[0014] Furthermore, the stator core is set inside the rotor cylinder, and rotor magnets are set between the rotor cylinder and the stator core. Ventilation channel steel is set between two adjacent stator core sections, and the two stator core sections and the ventilation channel steel form radially separated radial ventilation channels. The tensioning screw passes through multiple stator core sections, and both ends of the tensioning screw are fixed with stator end pressure plates. An air gap is set between the rotor magnets and the stator core.

[0015] Furthermore, the rotor cylinder is connected to the rotor non-drive end ring plate, the rotor non-drive end ring plate is equipped with a sealing structure M, and an eleventh ring plate is set between the rotor non-drive end ring plate and the fifth ring plate. One end of the eleventh ring plate is connected to the fifth ring plate, and the other end is connected to the rotor non-drive end ring plate. The eleventh ring plate, the fifth ring plate, the stator end pressure plate, the rotor non-drive end ring plate, and the rotor cylinder form a fourth space; the rotor non-drive end ring plate is connected to one end of the twelfth ring plate; a thirteenth ring plate is set below the eleventh ring plate, one end of the thirteenth ring plate is connected to the fifth ring plate, and the other end is connected to the other end of the twelfth ring plate. The fifth space is formed by the rotor non-drive end ring plate, the eleventh ring plate, the twelfth ring plate, the thirteenth ring plate and the fifth ring plate; the eleventh ring plate is evenly provided with fifth ventilation holes along the circumference to connect the fourth space with the fifth space; the first ring plate, the conical ring plate, the third ring plate and the rotor cylinder form the sixth space; the third ring plate located in the sixth space and the third space is provided with sixth ventilation holes to connect the sixth space with the third space; the fifth ring plate located in the second space, the third space and the fifth space is provided with seventh ventilation holes along the circumference, so that the second space and the third space are both connected to the fifth space.

[0016] Furthermore, the fifth and twelfth ring plates have multiple eighth ventilation holes on their circumferences for multiple first ventilation ducts to pass through. One end of the first ventilation duct is located inside the first equalizing chamber, and the other end is located outside the fifth space. The second, third, fourth, fifth, and twelfth ring plates have multiple ninth ventilation holes on their circumferences for multiple second ventilation ducts to pass through. One end of the second ventilation duct is located inside the third equalizing chamber, and the other end is located outside the fifth space. The fifth and twelfth ring plates have multiple tenth ventilation holes on their circumferences for multiple third ventilation ducts to pass through. One end of the third ventilation duct is located inside the second equalizing chamber, and the other end is located outside the fifth space. Multiple air outlet ducts are installed along the circumference of the twelfth ring plate.

[0017] Furthermore, the first ventilation duct, the second ventilation duct, and the third ventilation duct are combined into a set of air inlet ducts. The air inlet ducts and air outlet ducts are evenly distributed along the circumference, with a quantity of 6-8, and a blower is installed at the air inlet duct.

[0018] Furthermore, the radial dimensions of the air inlet cavity, the first air outlet cavity, and the second air outlet cavity are not less than 100 mm.

[0019] Furthermore, the radial dimension of the first equalizing chamber is not less than 150 mm; the radial dimension of the second equalizing chamber is not less than 100 mm; and the radial dimension of the third equalizing chamber is not less than 200 mm.

[0020] Furthermore, the air gap value is 4-5 mm.

[0021] Furthermore, the axial height of the radial ventilation duct is 3-4 mm.

[0022] Furthermore, the total axial length of the stator core is over 1500 mm, and the axial length of each stator core segment is 20-30 mm, which are evenly distributed axially.

[0023] Furthermore, the sealing structure M includes a rotor non-drive end ring plate, a sealing mounting ring plate, a pressure block, a C-type seal, and a sealing ring plate. The sealing mounting ring plate, pressure block, C-type seal, and sealing ring plate are installed on the rotor non-drive end ring plate. Grooves for installing C-type seals are machined on both ends of the inner diameter side of the rotor non-drive end ring plate, and the C-type seals are fixed by means of the pressure block. The lips of the C-type seals all face the inner diameter side, and they are squeezed and cooperated with the sealing ring plate installed on the sealing mounting ring plate to complete the sealing at the separation of the motor dynamic and static parts.

[0024] Furthermore, the number of the fourth ventilation holes is the same as that of the second or third ventilation holes, and their positions on the circumference are the same as those of the second and third ventilation holes.

[0025] The beneficial effects of this invention are as follows:

[0026] 1. By using radial ventilation cooling in the straight section near the end of the stator and the end of the stator, and tangential air gap cooling in the middle of the stator, the temperature gradient distribution of the stator along the axial direction is improved and the temperature difference of the stator is reduced.

[0027] 2. In this invention, after the cooling air enters the first equalizing chamber through the first ventilation duct, it spreads out on the circumference and flows to the radial ventilation channels distributed on the circumference of the stator core corresponding to the first equalizing chamber, to the air gap, and then enters the fourth space to cool the non-driving end of the stator coil. On the one hand, the cooling air cools the straight section of the stator near the non-driving end; on the other hand, the cooling air has a short travel distance to the non-driving end of the stator coil, which can fully cool the non-driving end of the stator coil and improve the efficiency of the cooling air.

[0028] 3. In this invention, the second cooling air enters the third equalizing chamber through the second ventilation duct and then disperses circumferentially, flowing into the air gap through the radial ventilation channels distributed on the circumference of the stator core corresponding to the third equalizing chamber, before entering the sixth space to cool the driving end of the stator coil. Because the second ventilation duct passes through the air inlet chamber and benefits from the cooling air within it, coupled with the isolation provided by the second ventilation duct, the cooling air flowing from the second ventilation duct to the third equalizing chamber is less affected by the heat radiating from the stator core. Therefore, sufficient cooling of the straight section of the stator near the driving end is ensured, as well as sufficient cooling of the driving end of the stator coil, thus improving the efficiency of the cooling air.

[0029] 4. In the first aspect of the present invention, the radial dimensions of the air inlet cavity, the first air outlet cavity, and the second air outlet cavity are large, which can reduce wind resistance and ensure that there is sufficient cooling air in the air inlet cavity to cool the stator core. After the cooling air exchanges heat with the stator core, it can ensure that the hot air flows smoothly out of the first air outlet cavity and the second air outlet cavity. In the second aspect, the large radial dimension of the air inlet cavity reduces wind resistance and allows for a sufficient amount of cooling air to enter. The cooling air flows from the corresponding air inlet cavity to the radial ventilation channel and the air gap, and then flows to the air outlet cavity through the radial ventilation channel. This results in a sufficiently large contact area between the cooling air and the stator core in the middle part of the stator, leading to a high heat exchange effect. As a result, each segment of the stator core and the stator coil located in each segment of the stator core receive more sufficient cooling air, improving the cooling effect and significantly reducing the axial temperature difference.

[0030] 5. In this invention, each stator core segment is 20% shorter than the stator core of a conventional large-capacity permanent magnet low-speed wind turbine. Since the stator core and coil are cooled by radial ventilation, the shorter the distance between the radial ventilation channels, the greater the heat dissipation area of ​​the stator core and stator coil, thus improving the cooling effect.

[0031] 6. In this invention, the axial height of the radial ventilation channel is 3-4 mm, which is more than 10% smaller than that of the prior art. The reduction in the height of the radial ventilation channel can increase the number of radial ventilation channels without significantly increasing the total length of the core, thereby increasing the heat dissipation surface area and improving the cooling effect.

[0032] 7. In this invention, the first ventilation duct, the second ventilation duct, and the third ventilation duct are combined into a set of air inlet ducts. The air inlet ducts and the air outlet ducts are evenly distributed along the circumference, with a quantity of 6-8. A blower is installed at the air inlet duct, which helps to make the cooling air flow more evenly on the circumference, reduce the circumferential air temperature difference, and ensure the ventilation and cooling effect.

[0033] In summary, the cooling air path of the present invention improves the cooling effect and reduces the stator temperature difference. Compared with the prior art, the wind resistance is reduced by more than 30%, the axial temperature difference is reduced by more than 20%, and the circumferential temperature difference is reduced by 20 to 25%, which improves the utilization rate of cooling air, thereby enabling the wind turbine to adapt to the unfavorable conditions of lower air density in high-altitude areas. Attached Figure Description

[0034] Figure 1. Longitudinal section view of wind turbine;

[0035] Figure 2. Non-drive end view of the wind turbine;

[0036] Figure 3. Cross section view of wind turbine AA;

[0037] Figure 4. Cross section view of wind turbine motor BB;

[0038] Figure 5. Cross section view of the wind turbine (CC section);

[0039] Figure 6. Cross section view of the wind turbine generator (DD);

[0040] Figure 7. Layout diagram of the cavity;

[0041] Figure 8. Partial view of sealing structure M;

[0042] Reference numerals: 1-Rotor cylinder, 2-Rotor magnet, 3-Rotor non-drive end ring plate, 4-Fifth space, 5-Eleventh ring plate, 6-Sealing mounting ring plate, 7-Stator coil, 8-Stator core, 9-First ring plate, 10-Third ring plate, 11-Fifth ring plate, 12-Firming plate, 13-Second ring plate, 14-Sixth ring plate, 15-Fourth ring plate, 16-Seventh ring plate, 17-Conical ring plate, 18-Eighth ring plate, 19-Ninth ring plate, 20-Tenth ring plate, 21-First ventilation duct, 22-Second ventilation duct, 23-Third ventilation duct, 24-First equalizing chamber, 25-Second equalizing chamber, 26-Third equalizing chamber Cavity, 27-Inlet cavity, 28-First outlet cavity, 29-First space, 30-Second space, 31-Third space, 32-Fourth space, 33-Sixth space, 34-Outlet duct, 35-Twelfth ring plate, 36-Thirteenth ring plate, 37-First ventilation hole, 38-Fourth ventilation hole, 39-Seventh ventilation hole, 40-Sixth ventilation hole, 41-Air gap, 42-Radial ventilation duct, 43-Ventilation channel steel, 44-Stator end pressure plate, 45-Tightening screw, 46-Second ventilation hole, 47-Third ventilation hole, 48-Sealing ring plate, 49-Blower, 50-Pressure block, 51-C-type seal, 52-Second outlet cavity. Embodiments of the present invention

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Solid lines and dashed arrows are used in the drawings to distinguish between cold and hot airflows. In the cross-sectional views, ⊕ and ⊙ are used to indicate the vertical inflow and outflow directions of the airflow. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] Example 1

[0045] A method for partitioned cooling of the stator of a high-altitude long-core wind turbine motor: After the cooling air enters the first equalizing chamber 24 from the first ventilation duct 21, it is dispersed in the circumferential direction and flows to the radial ventilation duct 42 distributed on the circumference of the stator core 8 in the first equalizing chamber 24 to the air gap 41, and then enters the fourth space 32 to cool the non-driving end of the stator coil 7. At the same time, the cooling air flows from the fourth space 32 to the fifth space 4.

[0046] After the cooling air enters the third equalizing chamber 26 from the second ventilation duct 22, it also disperses in the circumferential direction and flows to the radial ventilation duct 42 distributed on the circumference of the stator core 8 in the third equalizing chamber 26 to the air gap 41, and then enters the sixth space 33 to cool the driving end of the stator coil 7. At the same time, the cooling air enters the third space 31 from the sixth space 33 and then flows to the fifth space 4.

[0047] After entering the second equalizing chamber 25 from the third ventilation duct 23, the cooling air disperses in the circumferential direction and enters the air inlet chamber 27. It flows to the radial ventilation channels 42 distributed on the circumference of the stator core 8 corresponding to the air inlet chamber 27 and to the air gap 41. Through the air gap 41, it flows to the radial ventilation channels 42 distributed on the circumference of the first air outlet chamber 28 and the second air outlet chamber 52, and enters the first air outlet chamber 28 and the second air outlet chamber 52. The cooling air in the first air outlet chamber 28 enters the first space 29, the second space 30, and the fifth space 4. The cooling air in the second air outlet chamber 52 flows to the second space 30 and the fifth space 4. At this point, the three airflows converge in the fifth space 4 and are discharged through the air outlet duct 34 installed on the fifth space 4.

[0048] A cavity is formed between the stator core 8 and the stator frame. A third ring plate 10 is installed on the stator frame, dividing the cavity into left and right chambers. Multiple axial stiffeners 12 are spaced apart within the cavity, dividing it into multiple axial cavities. These axial cavities are evenly distributed along the circumference of the stator frame. Part of each axial cavity is an air inlet cavity 27, and part is an air outlet cavity. The air inlet cavity 27 and the air outlet cavity are adjacent to each other and evenly distributed along the circumference. The third ring plate 10 of the air inlet cavity 27... Ventilation channels are provided on the ring plate 10, making the air inlet cavity 27 longer in the axial direction; the air outlet cavity is divided into a first air outlet cavity 28 and a second air outlet cavity 52 by the third ring plate 10; a fourth space 32 is provided at the non-driving end of the stator coil 7, and a fifth space 4 is provided below the fourth space 32 and communicates with the fourth space 32; a first pressure equalization cavity 24 and a second pressure equalization cavity 25 are provided between the fifth space 4 and the axial cavity, and the second pressure equalization cavity 25 communicates with the air inlet cavity 27. A third equalizing cavity 26 is arranged adjacent to the drive end of the stator coil 7 in the axial cavity. A first ventilation duct 21, a second ventilation duct 22, and a third ventilation duct 23 are installed in the fifth space 4. The air outlet of the first ventilation duct 21 is located in the first equalizing cavity 24 and is connected to the first equalizing cavity 24. The air outlet of the second ventilation duct 22 passes through the air inlet cavity 27 and is located in the third equalizing cavity 26 and is connected to the third equalizing cavity 26. The air outlet of the third ventilation duct 23 is located in the second equalizing cavity 25 and is connected to the second equalizing cavity 25. A first space 29 and a second space 30 are arranged below the cavity. A first air outlet cavity 28 is connected to the first space 29, and a second air outlet cavity 52 is connected to the second space 30. The first space 29 and the second space 30 are connected, and the second space 30 is connected to the fifth space 4. A sixth space 33 and a third space 31 are installed below the first space 29 and the second space 30. The sixth space 33 is connected to the third space 31, and the third space 31 is connected to the fifth space 4.

[0049] In implementation, as shown in Figure 1, the cooling air is divided into three paths. One path of cooling air enters the first equalizing chamber 24 from the first ventilation duct 21, then spreads out on the circumference and flows to the radial ventilation channels 42 distributed on the circumference of the stator core 8 corresponding to the first equalizing chamber 24, to the air gap 41, and then enters the fourth space 32 to cool the non-driving end of the stator coil 7. On the one hand, the cooling air cools the straight section of the stator near the non-driving end; on the other hand, the cooling air has a short travel distance to the non-driving end of the stator coil 7, and can contact the non-driving end of the stator coil 7 more quickly, thus fully cooling the non-driving end of the stator coil 7 and improving the efficiency of the cooling air.

[0050] The second cooling air enters the third equalizing chamber 26 from the second ventilation duct 22, and then disperses circumferentially, flowing to the radial ventilation channels 42 distributed on the circumference of the stator core 8 in the third equalizing chamber 26, and then into the sixth space 33 to cool the driving end of the stator coil 7. Since the second ventilation duct 22 passes through the air inlet chamber 27, and is protected by the cooling air in the air inlet chamber 27, and with the isolation provided by the second ventilation duct 22, the cooling air in the second ventilation duct 22 is less affected by the heat radiated from the stator core 8 during its journey to the third equalizing chamber. Therefore, it can ensure sufficient cooling of the straight section of the stator near the driving end, and also ensure sufficient cooling of the driving end of the stator coil, thus improving the efficiency of the cooling air.

[0051] The third cooling air enters the second equalizing chamber 25 from the third ventilation duct 23, then disperses circumferentially into the air inlet chamber 27. It flows through the radial ventilation channels 42 distributed on the circumference of the stator core 8 corresponding to the air inlet chamber 27, to the air gap 41. Through the air gap 41, it flows through the radial ventilation channels 42 distributed on the circumference of the first air outlet chamber 28 and the second air outlet chamber 52, entering the first air outlet chamber 28 and the second air outlet chamber 52. Firstly, the large radial dimensions of the air inlet chamber 27, the first air outlet chamber 28, and the second air outlet chamber 52 reduce wind resistance, ensuring sufficient cooling air in the air inlet chamber 27 to cool the stator core 8. After heat exchange with the stator core 8, the cooling air ensures smooth flow of hot air out of the first air outlet chamber 28 and the second air outlet chamber 52. Secondly, the large radial dimension of the air inlet chamber 27 reduces wind resistance, allowing for a sufficient amount of cooling air to enter. The airflow in the air inlet 27 flows to the radial ventilation channel 42 and the air gap 41, and then to the corresponding air outlet 27 through the radial ventilation channel. This ensures that the contact area between the cooling air and the stator core in the middle part of the stator is large enough, the contact time is long enough, the heat exchange time is long enough, the heat exchange efficiency is high, and the axial temperature difference cooling effect is significant. Thirdly, when the cooling air flows from one end of the air inlet 27 to the other end, it will be affected by the heat dissipated by the stator core 8 and the stator coil 7, which will cause the temperature of the cooling air to rise. However, since the cooling air entering the air inlet 27 is sufficient, the difference in air volume in the radial ventilation channel 42 is reduced, which makes the contact time between the cooling air and the stator core 8 long, the heat exchange time long enough, and the heat exchange efficiency high. This allows each section of the stator core 8 and the stator coil 7 located at each section of the stator core 8 to receive more sufficient cooling air, improving the cooling effect and significantly reducing the temperature.

[0052] This invention provides cooling for the stator core 8, and is particularly suitable for high-altitude, large-capacity, low-speed permanent magnet wind turbines, where cooling is more difficult due to the low air density.

[0053] Even if the exhaust duct in the prior art (authorization announcement number CN110429747B, authorization announcement date November 20, 2020, titled "A Method for Reducing the Circumferential Temperature Difference between Motor Coils and Cores") is used as the air inlet, air enters from the exhaust duct, cooling air enters the exhaust cavity, flows to the stator ventilation groove corresponding to the exhaust cavity, and exits from the air gap 41 before being released from the stator. During this process, due to the small radial dimension of the exhaust cavity and high air resistance, less cooling air enters the exhaust cavity, resulting in a short direct contact time between the stator core 8 and heat exchange. The cooling time is short, resulting in low heat exchange efficiency. When cooling air flows from one end of the air outlet to the other, its temperature gradually increases due to the heat generated by the stator core 8 and stator coils 7. The hotter cooling air flows towards the stator ventilation groove, causing uneven cooling of each section of the stator core 8 and low cooling efficiency. The cooling air flows from the stator ventilation groove to the air gap 41, and from the air gap 41 to both ends of the stator before being released from the stator. Since the cooling air has already exchanged heat with the stator core 8 before flowing from the air gap 41 to both ends of the stator for further cooling, the cooling effect is low. Compared with the present invention, existing technologies struggle to achieve the cooling effect described in this invention.

[0054] Example 2

[0055] This embodiment further elaborates and supplements the implementation of the present invention based on Embodiment 1.

[0056] As shown in Figures 1-7, the stator base includes a first ring plate 9, a second ring plate 13, a third ring plate 10, a fourth ring plate 15, and a fifth ring plate 11 arranged sequentially on the inner diameter side back of the stator core 8, along with several axial stiffeners 12. A sixth ring plate 14 is arranged between the second ring plate 13 and the third ring plate 10, with one end connected to the second ring plate 13 and the other end connected to the third ring plate 10. A seventh ring plate 16 is arranged between the third ring plate 10 and the fifth ring plate 11, with one end connected to the third ring plate 10 and the other end connected to the fifth ring plate 11. The bottom end of the fourth ring plate 15 is connected to the seventh ring plate 16. The second ring plate 13, the sixth ring plate 14, the seventh ring plate 16, and the fourth ring plate 15 form a cavity, with the third ring plate 10 dividing the cavity into left and right chambers. One chamber is formed by the second ring plate 13, the third ring plate 10, and the sixth ring plate 14, and another chamber is formed by the third ring plate 10, the seventh ring plate 16, and the fourth ring plate 15; an inclined conical ring plate 17 is connected between the first ring plate 9 and the third ring plate 10, and the end of the second ring plate 13 is connected to the conical ring plate 17. The first ring plate 9, the second ring plate 13, and the conical ring plate 17 form a third pressure equalization chamber 26; a tenth ring plate 20 is provided between the fourth ring plate 15 and the fifth ring plate 11. One end of the tenth ring plate 20 is connected to the fourth ring plate 15, and the other end is connected to the fifth ring plate 11. The tenth ring plate 20 is located above the seventh ring plate 16; the fourth ring plate 15, the fifth ring plate 11, the seventh ring plate 16, and the tenth ring plate 20 form a first pressure equalization chamber 24 and a second pressure equalization chamber 25 through which cooling air passes.

[0057] The fourth ring plate 15, which forms the second equalizing chamber 25, is provided with first ventilation holes 37 at intervals along its circumference, so that the air inlet chamber 27 is connected to the second equalizing chamber 25; the sixth ring plate 14 is provided with second ventilation holes 46 at intervals along its circumference, and the second ventilation holes 46 are only distributed on the sixth ring plate 14 corresponding to the first air outlet chamber 28, for connecting the first space 29; the seventh ring plate 16 is provided with third ventilation holes 47 at intervals along its circumference, and the third ventilation holes 47 are only distributed on the seventh ring plate 16 corresponding to the second air outlet chamber 52, for connecting the second space 30; the second ventilation holes 46 and the third ventilation holes 47 are in the same position on the circumference.

[0058] The sixth ring plate 14 is located above the conical ring plate 17. The third ring plate 10, the sixth ring plate 14, and the conical ring plate 17 form a first space 29. An eighth ring plate 18 is set below the seventh ring plate 16. One end of the eighth ring plate 18 is connected to the third ring plate 10, and the other end is connected to the fifth ring plate 11. The third ring plate 10, the fifth ring plate 11, the seventh ring plate 16, and the eighth ring plate 18 form a second space 30. A fourth ventilation hole 38 is set along the circumference of the third ring plate 10 located in the first space 29 and the second space 30 for the first space 29 to connect to the second space 30. A ninth ring plate 19 is set below the eighth ring plate 18. One end of the ninth ring plate 19 is connected to the third ring plate 10, and the other end is connected to the fifth ring plate 11. The third ring plate 10, the fifth ring plate 11, the eighth ring plate 18, and the ninth ring plate 19 form a third space 31.

[0059] Example 3

[0060] This embodiment further elaborates and supplements the implementation of the present invention based on Embodiment 1 or Embodiment 2.

[0061] The stator core 8 is installed inside the rotor cylinder 1. The rotor magnet 2 is installed between the rotor cylinder 1 and the stator core 8. The ventilation channel steel 43 is installed between two adjacent stator core sections 8. The two stator core sections 8 and the ventilation channel steel 43 form a radially separated radial ventilation channel 42. The tensioning screw 45 passes through multiple stator core sections 8. Both ends of the tensioning screw 45 are fixed by the stator end pressure plate 44. An air gap 41 is provided between the rotor magnet 2 and the stator core 8.

[0062] The rotor cylinder 1 is connected to the rotor non-drive end ring plate 3. The rotor non-drive end ring plate 3 is equipped with a sealing structure M. An eleventh ring plate 5 is set between the rotor non-drive end ring plate 3 and the fifth ring plate 11. One end of the eleventh ring plate 5 is connected to the fifth ring plate 11, and the other end is connected to the rotor non-drive end ring plate 3. The eleventh ring plate 5, the fifth ring plate 11, the stator end pressure plate 44, the rotor non-drive end ring plate 3, and the rotor cylinder 1 form a fourth space 32. The rotor non-drive end ring plate 3 is connected to one end of the twelfth ring plate 35. A thirteenth ring plate 36 is set below the eleventh ring plate 5. One end of the thirteenth ring plate 36 is connected to the fifth ring plate 11, and the other end is connected to the other end of the twelfth ring plate 35. 3. The eleventh ring plate 5, the twelfth ring plate 35, the thirteenth ring plate 36 and the fifth ring plate 11 form the fifth space 4; the eleventh ring plate 5 is evenly provided with fifth ventilation holes along the circumference for the fourth space 32 to connect with the fifth space 4; the first ring plate 9, the conical ring plate 17, the third ring plate 10 and the rotor cylinder 1 form the sixth space 33; the third ring plate 10 located in the sixth space 33 and the third space 31 is provided with sixth ventilation holes 40 for the sixth space 33 to connect with the third space 31; the fifth ring plate 11 located in the second space 30, the third space 31 and the fifth space 4 is provided with seventh ventilation holes 39 along the circumference, so that the second space 30 and the third space 31 are both connected to the fifth space 4.

[0063] The fifth ring plate 11 and the twelfth ring plate 35 have multiple eighth ventilation holes on their circumferences for multiple first ventilation ducts 21 to pass through. One end of the first ventilation duct 21 is located inside the first equalizing chamber 24, and the other end is located outside the fifth space 4. The second ring plate 13, the third ring plate 10, the fourth ring plate 15, the fifth ring plate 11, and the twelfth ring plate 35 have multiple ninth ventilation holes on their circumferences for multiple second ventilation ducts 22 to pass through. One end of the second ventilation duct 22 is located inside the third equalizing chamber 26, and the other end is located outside the fifth space 4. The fifth ring plate 11 and the twelfth ring plate 35 have multiple tenth ventilation holes on their circumferences for multiple third ventilation ducts 23 to pass through. One end of the third ventilation duct 23 is located inside the second equalizing chamber 25, and the other end is located outside the fifth space 4. Multiple air outlet ducts 34 are installed along the circumference of the twelfth ring plate 35.

[0064] Example 4

[0065] This embodiment further elaborates and supplements the implementation of the present invention based on Embodiment 1, Embodiment 2 or Embodiment 3.

[0066] The first ventilation duct 21, the second ventilation duct 22, and the third ventilation duct 23 are combined into a set of air inlet ducts. The air inlet ducts and air outlet ducts 34 are evenly distributed along the circumference, with a quantity of 6-8. A blower 49 is installed at the air inlet duct to facilitate more uniform flow of cooling air around the circumference, which helps to ensure the ventilation and cooling effect, reduce the circumferential air temperature difference, and ensure the ventilation and cooling effect.

[0067] The radial dimensions of the air inlet cavity 27, the first air outlet cavity 28, and the second air outlet cavity 52 are not less than 100 mm. Firstly, the large radial dimensions of the air inlet cavity 27, the first air outlet cavity 28, and the second air outlet cavity 52 reduce air resistance, ensuring sufficient cooling air in the air inlet cavity 27 to cool the stator core 8. After heat exchange with the stator core 8, the hot air can flow smoothly out of the first air outlet cavity 28 and the second air outlet cavity 52. ​​Secondly, the large radial dimension of the air inlet cavity 27 reduces air resistance, allowing for a sufficient amount of cooling air to enter. The cooling air flows from the corresponding air inlet cavity 27 to the radial ventilation channel 42 and the air gap 41, and then through the radial ventilation channel to the corresponding air outlet cavity. This ensures a sufficiently large contact area between the cooling air and the stator core in the middle part of the stator, and a sufficient contact time. The first aspect is that the cooling air has a long contact time with the stator core 8 and the stator coil 7, resulting in a long heat exchange time, high heat exchange efficiency, and significant axial temperature difference cooling effect. The second aspect is that when the cooling air flows from one end of the air inlet cavity 27 to the other end, it will be affected by the heat dissipated by the stator core 8 and the stator coil 7, which will cause the temperature of the cooling air to rise. However, since the cooling air entering the air inlet cavity 27 is sufficient, the difference in air volume of the radial ventilation channel 42 is reduced, which makes the contact time between the cooling air and the stator core 8 longer, the heat exchange time longer, and the heat exchange effect higher. This allows each section of the stator core 8 and the stator coil 7 located at each section of the stator core 8 to receive more sufficient cooling air, improving the cooling effect and significantly reducing the temperature.

[0068] The radial dimension of the first equalizing chamber 24 is not less than 150 mm; the radial dimension of the second equalizing chamber 25 is not less than 100 mm; and the radial dimension of the third equalizing chamber 26 is not less than 200 mm.

[0069] The air gap value is 4-5 mm. This ensures sufficient space for cooling air to flow.

[0070] The axial height of the radial ventilation channel 42 is 3-4 mm. This axial height is more than 10% smaller than that of the prior art. The reduction in the height of the radial ventilation channel 42 allows for an increase in the number of radial ventilation channels 42 without significantly increasing the overall length of the core, thereby increasing the heat dissipation surface area and improving the cooling effect.

[0071] The total axial length of the stator core 8 is over 1500 mm, and the axial length of each segment of the stator core 8 is 20-30 mm, evenly distributed axially. Compared with the prior art, each segment of the stator core 8 in this invention is 20% shorter than the stator core 8 of a conventional large-capacity permanent magnet low-speed wind turbine. Since the stator core 8 and the stator coil 7 are radially ventilated and cooled, the shorter the distance between the radial ventilation channels 42, the greater the heat dissipation area of ​​the stator core 8 and the stator coil 7, thus improving the cooling effect.

[0072] The sealing structure M includes a rotor non-drive end ring plate 3, a sealing mounting ring plate 6, a pressure block 50, a C-type seal 51, and a sealing ring plate 48. The sealing mounting ring plate 6, the pressure block 50, the C-type seal 51, and the sealing ring plate 48 are installed on the rotor non-drive end ring plate 3. Grooves for installing the C-type seal 51 are machined on both ends of the inner diameter side of the rotor non-drive end ring plate 3, and the C-type seal 51 is fixed by means of the pressure block 50. The lips of the C-type seal 51 all face the inner diameter side, and are pressed and fitted with the sealing ring plate 48 installed on the sealing mounting ring plate 6 to complete the sealing at the motor dynamic and static separation point.

[0073] The number of fourth ventilation holes 38 is the same as that of the second ventilation holes 46 or the third ventilation holes 47, and their positions on the circumference are the same as those of the second ventilation holes 46 and the third ventilation holes 47.

Claims

1. A method for zoned cooling of the stator of a high-altitude long-core wind turbine, characterized in that: After the cooling air enters the first equalizing chamber (24) from the first ventilation duct (21), it disperses in the circumferential direction and flows to the radial ventilation duct (42) distributed on the circumference of the stator core (8) corresponding to the first equalizing chamber (24) to the air gap (41), and then enters the fourth space (32) to cool the non-driving end of the stator coil (7). At the same time, the cooling air flows from the fourth space (32) to the fifth space (4). After the cooling air enters the third equalizing chamber (26) from the second ventilation duct (22), it also disperses in the circumferential direction and flows to the radial ventilation duct (42) distributed on the circumference of the stator core (8) in the third equalizing chamber (26) to the air gap (41), and then enters the sixth space (33) to cool the driving end of the stator coil (7). At the same time, the cooling air enters the third space (31) from the sixth space (33) and then flows to the fifth space (4). After the cooling air enters the second equalizing chamber (25) from the third ventilation duct (23), it disperses in the circumferential direction and enters the air inlet chamber (27). It flows to the radial ventilation channel (42) distributed on the circumference of the stator core (8) corresponding to the air inlet chamber (27) and to the air gap (41). It flows through the air gap (41) to the radial ventilation channel (42) distributed on the circumference of the first air outlet chamber (28) and the second air outlet chamber (52). It enters the first air outlet chamber (28) and the second air outlet chamber (52). The cooling air in the first air outlet chamber (28) enters the first space (29), the second space (30), and the fifth space (4). The cooling air in the second air outlet chamber (52) flows to the second space (30) and the fifth space (4). At this point, the three air flows into the fifth space (4) and is discharged through the air outlet duct (34) installed on the fifth space (4). A cavity is formed between the stator core (8) and the stator frame. A third ring plate (10) is installed on the stator frame, which divides the cavity into two chambers, left and right. Multiple axial stiffeners (12) are spaced apart in the chamber, dividing the chamber into multiple axial cavities. The axial cavities are evenly distributed along the circumference of the stator frame. Part of the multiple axial cavities is an air inlet cavity (27), and part is an air outlet cavity. The air inlet cavity (27) and the air outlet cavity are arranged adjacent to each other and evenly distributed along the circumference. Ventilation holes are provided on the third ring plate (10) of the air inlet cavity (27). The air inlet cavity (27) is formed into an axially longer air inlet cavity (27); the air outlet cavity is divided into a first air outlet cavity (28) and a second air outlet cavity (52) by a third ring plate (10); a fourth space (32) is provided at the non-driving end of the stator coil (7), and a fifth space (4) is provided below the fourth space (32) and communicates with the fourth space (32); a first equalizing cavity (24) and a second equalizing cavity (25) are provided between the fifth space (4) and the axial cavity, the second equalizing cavity (25) communicates with the air inlet cavity (27), and the axial cavity is close to the stator coil ( 7) A third equalizing chamber (26) is arranged adjacent to the driving end. A first ventilation duct (21), a second ventilation duct (22), and a third ventilation duct (23) are installed in the fifth space (4). The air outlet of the first ventilation duct (21) is placed in the first equalizing chamber (24) and communicates with the first equalizing chamber (24). The air outlet of the second ventilation duct (22) passes through the air inlet chamber (27) and is placed in the third equalizing chamber (26) and communicates with the third equalizing chamber (26). The air outlet of the third ventilation duct (23) is placed in the second equalizing chamber (25) and communicates with the second equalizing chamber. (25) Connecting; A first space (29) and a second space (30) are set below the cavity. The first air outlet cavity (28) connects to the first space (29), and the second air outlet cavity (52) connects to the second space (30). The first space (29) and the second space (30) are connected, and the second space (30) connects to the fifth space (4). A sixth space (33) and a third space (31) are installed below the first space (29) and the second space (30). The sixth space (33) connects to the third space (31), and the third space (31) connects to the fifth space (4).

2. The method for partitioned cooling of the stator of a high-altitude long-core wind turbine as described in claim 1, characterized in that: The stator base includes a first ring plate (9), a second ring plate (13), a third ring plate (10), a fourth ring plate (15), and a fifth ring plate (11) arranged sequentially on the back of the inner diameter side of the stator core (8), and several axial stiffeners (12). A sixth ring plate (14) is arranged between the second ring plate (13) and the third ring plate (10). One end of the sixth ring plate (14) is connected to the second ring plate (13), and the other end is connected to the third ring plate (10). A seventh ring plate (16) is set between the second ring plate (13) and the fifth ring plate (11). One end of the seventh ring plate (16) is connected to the third ring plate (10), and the other end is connected to the fifth ring plate (11). The bottom end of the fourth ring plate (15) is connected to the seventh ring plate (16). The cavity is formed by the second ring plate (13), the sixth ring plate (14), the seventh ring plate (16), and the fourth ring plate (15). The third ring plate (10) divides the cavity into two chambers, one of which is formed by the second ring plate (13), the sixth ring plate (14), the seventh ring plate (16), and the fourth ring plate (15). The first ring plate (9), the second ring plate (13), the third ring plate (10), and the sixth ring plate (14) form a third pressure equalization chamber (26). The second ring plate (13) is connected to the third ring plate (10) by an inclined conical ring plate (17). The end of the second ring plate (13) is connected to the conical ring plate (17). The first ring plate (9), the second ring plate (13), and the conical ring plate (17) form the third pressure equalization chamber (26). A tenth ring plate (20) is provided between the fourth ring plate (15) and the fifth ring plate (11). One end of the tenth ring plate (20) is connected to the fourth ring plate (15), and the other end is connected to the fifth ring plate (11). The tenth ring plate (20) is located above the seventh ring plate (16). The fourth ring plate (15), the fifth ring plate (11), the seventh ring plate (16), and the tenth ring plate (20) form the first equalizing chamber (24) and the second equalizing chamber (25) through which the cooling air passes.

3. The method for partitioned cooling of the stator of a high-altitude long-core wind turbine as described in claim 2, characterized in that: The fourth ring plate (15) of the second equalizing chamber (25) is provided with first ventilation holes (37) at circumferential intervals so that the air inlet chamber (27) is connected to the second equalizing chamber (25); the sixth ring plate (14) is provided with second ventilation holes (46) at circumferential intervals, and the second ventilation holes (46) are only distributed on the sixth ring plate (14) corresponding to the first air outlet chamber (28), for connecting the first space (29); the seventh ring plate (16) is provided with third ventilation holes (47) at circumferential intervals, and the third ventilation holes (47) are only distributed on the seventh ring plate (16) corresponding to the second air outlet chamber (52), for connecting the second space (30); the second ventilation holes (46) and the third ventilation holes (47) are in the same position on the circumference.

4. The method for partitioned cooling of the stator of a high-altitude long-core wind turbine as described in claim 3, characterized in that: The sixth ring plate (14) is located above the conical ring plate (17). The third ring plate (10), the sixth ring plate (14), and the conical ring plate (17) form a first space (29). An eighth ring plate (18) is set below the seventh ring plate (16). One end of the eighth ring plate (18) is connected to the third ring plate (10), and the other end is connected to the fifth ring plate (11). The third ring plate (10), the fifth ring plate (11), the seventh ring plate (16), and the eighth ring plate (18) form a second space (30). A fourth ventilation hole (38) is provided along the circumference of the third ring plate (10) in the first space (29) and the second space (30) for connecting the first space (29) to the second space (30); a ninth ring plate (19) is provided below the eighth ring plate (18), one end of the ninth ring plate (19) is connected to the third ring plate (10), and the other end is connected to the fifth ring plate (11). The third ring plate (10), the fifth ring plate (11), the eighth ring plate (18) and the ninth ring plate (19) form the third space (31).

5. A method for partitioned cooling of the stator of a high-altitude long-core wind turbine as described in any one of claims 1-4, characterized in that: The stator core (8) is set inside the rotor cylinder (1). The rotor magnet (2) is set between the rotor cylinder (1) and the stator core (8). The ventilation channel steel (43) is set between two adjacent stator core sections (8). The two stator core sections (8) and the ventilation channel steel (43) form a radially separated radial ventilation channel (42). The tensioning screw (45) passes through multiple stator core sections (8). Both ends of the tensioning screw (45) are fixed with stator end pressure plates (44). An air gap (41) is set between the rotor magnet (2) and the stator core (8).

6. The method for partitioned cooling of the stator of a high-altitude long-core wind turbine as described in claim 5, characterized in that: The rotor cylinder (1) is connected to the rotor non-drive end ring plate (3). The rotor non-drive end ring plate (3) is equipped with a sealing structure M. An eleventh ring plate (5) is set between the rotor non-drive end ring plate (3) and the fifth ring plate (11). One end of the eleventh ring plate (5) is connected to the fifth ring plate (11), and the other end is connected to the rotor non-drive end ring plate (3). The eleventh ring plate (5), the fifth ring plate (11), the stator end pressure plate (44), the rotor non-drive end ring plate (3), and the rotor cylinder (1) form a fourth space (32). The rotor non-drive end ring plate (3) is connected to one end of the twelfth ring plate (35). A thirteenth ring plate (36) is set below the eleventh ring plate (5). One end of the thirteenth ring plate (36) is connected to the fifth ring plate (11), and the other end is connected to the other end of the twelfth ring plate (35). The rotor non-drive end ring plate (3) and the thirteenth ring plate (35) are connected to each other. The first ring plate (5), the twelfth ring plate (35), the thirteenth ring plate (36) and the fifth ring plate (11) form the fifth space (4); the eleventh ring plate (5) is evenly provided with the fifth ventilation hole along the circumference for the fourth space (32) to connect with the fifth space (4); the first ring plate (9), the conical ring plate (17), the third ring plate (10) and the rotor cylinder (1) form the sixth space (33); the third ring plate (10) located in the sixth space (33) and the third space (31) is provided with the sixth ventilation hole (40) for the sixth space (33) to connect with the third space (31); the fifth ring plate (11) located in the second space (30), the third space (31) and the fifth space (4) is provided with the seventh ventilation hole (39) along the circumference, so that the second space (30) and the third space (31) are both connected with the fifth space (4).

7. The method for partitioned cooling of the stator of a high-altitude long-core wind turbine as described in claim 6, characterized in that: The fifth ring plate (11) and the twelfth ring plate (35) have multiple eighth ventilation holes on their circumferences for multiple first ventilation ducts (21) to pass through. One end of the first ventilation duct (21) is located inside the first equalizing chamber (24), and the other end is located outside the fifth space (4). The second ring plate (13), the third ring plate (10), the fourth ring plate (15), the fifth ring plate (11), and the twelfth ring plate (35) have multiple ninth ventilation holes on their circumferences for multiple second ventilation ducts. 22) Passing through, one end of the second ventilation duct (22) is located inside the third equalizing chamber (26), and the other end is located outside the fifth space (4); the fifth ring plate (11) and the twelfth ring plate (35) have multiple tenth ventilation holes on the circumference for multiple third ventilation ducts (23) to pass through, one end of the third ventilation duct (23) is located inside the second equalizing chamber (25), and the other end is located outside the fifth space (4); multiple air outlet ducts (34) are installed on the twelfth ring plate (35) along the circumference.

8. The method for partitioned cooling of the stator of a high-altitude long-core wind turbine as described in claim 7, characterized in that: The first ventilation duct (21), the second ventilation duct (22) and the third ventilation duct (23) are combined into a set of air inlet ducts. The air inlet ducts and the air outlet ducts (34) are evenly distributed along the circumference, with a quantity of 6-8, and a blower (49) is installed at the air inlet duct.

9. A method for partitioned cooling of the stator of a high-altitude long-core wind turbine as described in any one of claims 1-4, characterized in that: The radial dimensions of the air inlet cavity (27), the first air outlet cavity (28), and the second air outlet cavity (52) are not less than 100 mm.

10. A method for partitioned cooling of the stator of a high-altitude long-core wind turbine as described in any one of claims 1-4, characterized in that: The first equalizing chamber (24) has a radial dimension of not less than 150 mm; the second equalizing chamber (25) has a radial dimension of not less than 100 mm; and the third equalizing chamber (26) has a radial dimension of not less than 200 mm.

11. A method for partitioned cooling of the stator of a high-altitude long-core wind turbine as described in claim 5, characterized in that: The air gap (41) value is 4-5 mm.

12. The method for partitioned cooling of the stator of a high-altitude long-core wind turbine as described in claim 5, characterized in that: The radial ventilation duct (42) has an axial height of 3-4 mm.

13. A method for partitioned cooling of the stator of a high-altitude long-core wind turbine as described in claim 5, characterized in that: The total axial length of the stator core (8) is more than 1500 mm, and the axial length of each stator core (8) segment is 20-30 mm, and they are evenly distributed in the axial direction.

14. The method for partitioned cooling of the stator of a high-altitude long-core wind turbine as described in claim 6, characterized in that: The sealing structure M includes a rotor non-drive end ring plate (3), a sealing mounting ring plate (6), a pressure block (50), a C-type seal (51), and a sealing ring plate (48). The rotor non-drive end ring plate (3) is equipped with the sealing mounting ring plate (6), the pressure block (50), the C-type seal (51), and the sealing ring plate (48). Grooves for installing the C-type seal (51) are machined on both ends of the inner diameter side of the rotor non-drive end ring plate (3), and the C-type seal (51) is fixed by means of the pressure block (50). The lips of the C-type seal (51) face the inner diameter side and are squeezed and cooperated with the sealing ring plate (48) installed on the sealing mounting ring plate (6) to complete the sealing at the motor dynamic and static separation point.

15. A method for partitioned cooling of the stator of a high-altitude long-core wind turbine as described in claim 4, characterized in that: The number of the fourth ventilation holes (38) is the same as that of the second ventilation holes (46) or the third ventilation holes (47), and the positions of the second ventilation holes (46) and the third ventilation holes (47) on the circumference are the same.

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