Split-tooth permanent magnet vernier motor and wind turbine generator including the same

Abstract

The present invention discloses a split-tooth permanent magnet vernier motor and a wind turbine generator including the same. The split-tooth permanent magnet vernier motor includes an inner stator and an outer rotor, an air gap is provided between the inner stator and the outer rotor, the inner stator includes a plurality of stator cores and armature windings arranged in pairs, the stator core includes stator armature teeth and stator modulation teeth, the armature winding is arranged around the corresponding stator armature teeth, the stator armature teeth are split into pairs of stator modulation teeth along their radial direction toward one side of the outer rotor, a first modulation slot is formed between the pairs of stator modulation teeth, and the first modulation slot is chamfered at the edge position of its slot bottom. This arrangement is not only beneficial to the manufacturing process of the motor, but also can widen the magnetic circuit at the chamfer position, thereby making the magnetic density distribution of the stator core at this position relatively sparse, alleviating the saturation degree of the stator core, and at the same time can also use the first modulation slot to reduce the overall weight of the motor, which helps to reduce the heat dissipation difficulty of the motor.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and in particular to a split-tooth permanent magnet vernier motor and a wind turbine generator comprising the same. Background Art

[0002] The permanent magnet vernier motor is a motor based on the principle of magnetic field modulation. It can modulate the rotor permanent magnet with a lower speed into the stator air gap magnetic field with a higher speed, thereby achieving the effect of "self-increasing speed" and realizing better output torque density and higher transmission reliability. In many low-speed direct drive applications, such as electric vehicle drive, wind power generation drive and other fields, unlike general permanent magnet synchronous motors, the permanent magnet vernier motor can omit mechanical transmission devices such as gearboxes and gearboxes, and is directly driven, which has a larger application scenario.

[0003] Conventional permanent magnet vernier motors have a large number of rotor pole pairs, nearly equal to the number of stator teeth, while the stator has a relatively small number of pole pairs. The stator's high number of teeth and low number of poles results in excessively long end-winding spans when using integer-slot distributed windings. This increases losses, reduces efficiency, and increases winding weight and cost. A split-tooth permanent magnet vernier motor utilizes the small teeth on the stator pole shoes as modulation poles, reducing the number of armature winding slots and addressing the large end-winding span issue with concentrated windings.

[0004] Most of the concentrated winding split-tooth permanent magnet vernier motors are unilateral motors. The majority of the pole-pair magnetic fields are modulated by the split-tooth modulation magnet blocks to produce a rotating low-pole-pair magnetic field and couple with the armature winding. However, the modulation effect will also produce a large number of unused harmonic magnetic fields. The rich harmonic magnetic fields all form a closed magnetic circuit through the stator armature teeth and the stator yoke, so that the stator armature teeth and the stator yoke are designed to be wider to avoid core saturation. Especially in high-power (above megawatt) applications, the armature magnetic field is strong and the harmonic distortion is more serious, which aggravates the core saturation. The stator armature teeth and the stator yoke have to be designed to be wider, and the weight of the motor is further increased. In addition, the wider stator armature teeth and stator yoke also compress the effective space of the stator slots, reducing the electrical load of the motor. If the electrical load is kept unchanged, the copper loss of the motor will undoubtedly increase, the efficiency will decrease and the heat dissipation difficulty of the motor will be increased. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the defects of the prior art split-tooth permanent magnet vernier motor in that its weight and heat dissipation difficulty are increased in order to avoid core saturation, and to provide a split-tooth permanent magnet vernier motor and a wind turbine generator comprising the same.

[0006] The present invention solves the above technical problems through the following technical solutions:

[0007] A split-tooth permanent magnet vernier motor includes an inner stator and an outer rotor, with an air gap provided between the inner stator and the outer rotor, and is characterized in that:

[0008] The inner stator includes a plurality of stator cores and armature windings arranged in pairs. The stator cores include stator armature teeth and stator modulation teeth. The armature windings are arranged around the corresponding stator armature teeth. The stator armature teeth are split into pairs of stator modulation teeth along their radial direction toward the side of the outer rotor. A first modulation slot is formed between the pairs of stator modulation teeth, and the first modulation slot is chamfered at the bottom edge of the slot.

[0009] In the split-tooth permanent magnet vernier motor, the armature winding of the inner stator is arranged around the corresponding stator armature teeth. When powered, the current in the armature winding generates a corresponding magnetic field that interacts with the magnetic field of the outer rotor during rotation, thereby generating torque to drive the motor to rotate. In this process, the stator armature teeth are used to split pairs of stator modulation teeth toward the outer rotor side as modulation poles, reducing the number of slots in the armature winding and solving the problem of large end winding span. At the same time, a first modulation slot can be formed between the pairs of stator modulation teeth, and a chamfer is provided at the bottom edge of the first modulation slot, which is not only conducive to process manufacturing, but also can widen the magnetic circuit at this position, thereby making the magnetic density distribution of the stator core at this position relatively sparse, alleviating the saturation degree of the stator core, avoiding the stator armature teeth being designed with a wider size, thereby increasing the overall weight of the motor, and the first modulation slot can also be used to reduce the overall weight of the motor, which helps to reduce the difficulty of heat dissipation of the motor.

[0010] Furthermore, armature slots are provided between the stator armature teeth of adjacent stator cores, and the armature windings are arranged around the corresponding stator armature teeth in the armature slots;

[0011] In the circumferential direction of the stator core, the width of the stator modulated tooth is d1, and the minimum distance between the chamfer and the adjacent armature slot is d2; wherein d1 < d2 < 1.2d1;

[0012] And / or, in the radial direction of the stator core, the extension dimension of the stator modulation tooth is S1, and the depth dimension of the first modulation slot is S2; wherein, 0.48S1<S2<0.56S1.

[0013] In this solution, the armature winding is specifically arranged in the armature slot and surrounds the corresponding stator armature tooth. By setting the minimum distance between the chamfer provided in the first modulation slot and the adjacent armature slot to a certain proportion of the width of the stator modulation tooth, the chamfer is used to widen the magnetic circuit of the first modulation slot at the edge of its slot bottom, so that the magnetic circuit corresponding to the stator armature tooth can be evenly transitioned to the stator modulation tooth. While reducing the overall weight of the motor, the magnetic flux density distribution of the stator core is avoided from varying too much, thereby alleviating the saturation of the stator core as much as possible. At the same time, in the radial direction of the stator core, the depth dimension of the first modulation slot is set to a certain proportion of the extension dimension of the stator modulation tooth, so as to avoid the depth of the first modulation slot being too deep, resulting in the distance between its slot bottom and the corresponding armature slot being too small, thereby making the magnetic flux density distribution of the stator core at this position relatively dense.

[0014] Furthermore, in adjacent stator cores, a second modulation slot is provided between adjacent stator modulation teeth, the position of the second modulation slot corresponds to the armature slot between the same stator modulation teeth, and the second modulation slot is connected to the corresponding armature slot.

[0015] In this solution, by opening a second modulation slot at a position corresponding to the armature slot on the stator core and connecting the second modulation slot to the armature slot at the corresponding position, it is more convenient to surround the armature winding around the periphery of the stator armature teeth. At the same time, the second modulation slot can also be used to further reduce the overall weight of the motor and help reduce the difficulty of heat dissipation of the motor.

[0016] Furthermore, the pairs of stator modulation teeth split from the stator armature teeth are symmetrically arranged around the central axis of the same stator armature tooth.

[0017] In this solution, the stator modulation teeth split from the stator armature teeth are symmetrically distributed with respect to the central axis of the stator armature teeth, so that the magnetic flux density distribution of the stator core is more uniform and symmetrical, which is more conducive to the stability of the motor operation.

[0018] Furthermore, the central angle corresponding to the stator core is θ1, the central angle corresponding to the span between the paired stator modulation teeth is θ2, the outer edge surfaces of the stator modulation teeth facing the outer rotor are all arc surfaces, and the central angle corresponding to the arc surfaces is θ3; wherein, 0.75θ1<θ2<0.82θ1, 0.45θ2<2θ3<0.55θ2.

[0019] In this solution, the central angle corresponding to the span between paired stator modulated teeth is set to a certain proportion of the central angle corresponding to the stator core, so as to avoid the spacing between adjacent stator modulated teeth in adjacent stator cores being too large or too small, so as to reduce the overall weight of the motor as much as possible and improve the overall heat dissipation performance of the motor without damaging the original performance of the motor; at the same time, the central angle corresponding to the outer edge surface of each stator modulated tooth is set to a certain proportion of the central angle corresponding to the span between paired stator modulated teeth, so as to avoid the outer edge surface of each stator modulated tooth having a relatively small size, thereby narrowing the magnetic circuit at its outer edge surface position, making the magnetic density distribution at this location relatively dense, which in turn aggravates the saturation degree of the stator core.

[0020] Furthermore, a tooth weight reduction groove is formed on the stator armature tooth at an end portion close to the outer rotor, and the tooth weight reduction groove is connected to the first modulation groove formed on the same stator armature tooth.

[0021] In this solution, by further opening a tooth weight-reducing slot on the stator armature tooth and connecting the tooth weight-reducing slot with the first modulation slot on the same stator armature tooth, the amount of stator core used can be further reduced, thereby further reducing the overall weight of the motor and reducing the difficulty of heat dissipation of the motor.

[0022] Furthermore, the tooth weight-reducing groove and the corresponding first modulation groove cooperate with each other to form a "T"-shaped groove, the "T"-shaped groove is a symmetrical structure, and the symmetry axis of the "T"-shaped groove coincides with the central axis of the stator armature tooth.

[0023] In this solution, since the magnetic flux distribution of the stator armature teeth at their symmetrical center axis positions is relatively sparse, the positions of the tooth weight-reducing slots are adjusted so that the "T"-shaped slots formed by the tooth weight-reducing slots and the corresponding first modulation slots can be symmetrically arranged with respect to the center axis of the stator armature teeth. This allows the overall weight of the motor to be reduced by utilizing the tooth weight-reducing slots while minimizing the impact on the magnetic flux distribution in the stator armature teeth.

[0024] Furthermore, the stator core also includes a stator yoke, which is arranged on the side of the stator armature tooth away from the outer rotor along its radial direction, and a yoke weight-reducing groove is provided on the inner side wall of the stator yoke away from the stator armature tooth corresponding to the tooth weight-reducing groove.

[0025] In this scheme, a complete stator core is formed by combining a stator yoke with stator armature teeth and stator modulation teeth. Adjacent stator armature teeth are connected through the stator yoke to ensure that the magnetic lines of force in adjacent stator armature teeth can be transmitted through the stator yoke. In this case, the stator yoke is away from the inner wall of the stator armature teeth at the position corresponding to the tooth weight-reducing groove, and the magnetic density distribution is relatively sparse. Therefore, the stator yoke is provided with a yoke weight-reducing groove at the corresponding position. Similarly, while the yoke weight-reducing groove is used to reduce the overall weight of the motor, the influence on the magnetic density distribution in the stator yoke is avoided as much as possible.

[0026] Furthermore, the cross-section of the yoke weight-reducing groove is semicircular, and the center of the semicircle is located at the intersection of the central axis of the stator armature tooth and the arc where the inner side wall of the stator iron yoke is located;

[0027] And / or, the minimum distance between the bottom of the tooth weight-reducing groove and the corresponding yoke weight-reducing groove is d3, and the depth dimension of the tooth weight-reducing groove is S3, wherein 0.75d3<S3<0.85d3.

[0028] In this solution, the cross-section of the yoke weight-reducing groove is set to a semicircular shape, and the center point of the semicircle is set at the intersection of the central axis of the stator armature tooth and the arc of the inner wall of the stator iron yoke, so that the setting of the yoke weight-reducing groove is more regular, so as to avoid the uneven setting position causing the structure of the stator core to become more complicated and causing too much influence on the magnetic flux distribution in the stator core; in addition, the depth size of the tooth weight-reducing groove is set to a certain proportion of the minimum distance between the bottom of the tooth weight-reducing groove and the corresponding yoke weight-reducing groove, so as to avoid the depth of the tooth weight-reducing groove being too deep, or the minimum distance between the tooth weight-reducing groove and the corresponding yoke weight-reducing groove being too small, which structurally affects the stability of the motor operation and also has a greater impact on the magnetic flux distribution on the stator armature teeth, thereby reducing the efficiency of the motor.

[0029] Furthermore, armature slots are provided between the stator armature teeth of adjacent stator cores, and the armature windings are arranged around the corresponding stator armature teeth in the armature slots;

[0030] In the circumferential direction of the stator core, the width of the stator armature tooth minus the width of the tooth weight-reducing slot is d4, and the minimum distance between the yoke weight-reducing slot and the bottom of the adjacent armature slot is d5; wherein 0.45d4<d5<0.6d4.

[0031] In this solution, the armature winding is specifically arranged in the armature slot on the corresponding stator armature tooth. By setting the minimum distance between the yoke weight-reducing slot and the bottom of the armature slot at the adjacent position to a specific ratio of the width dimension of the stator armature tooth minus the width dimension of the tooth weight-reducing slot, the minimum distance between the yoke weight-reducing slot and the bottom of the armature slot at the adjacent position is prevented from being too small, thereby preventing the magnetic circuit at this location from being too narrow, and further preventing the magnetic density distribution from being too tight.

[0032] Furthermore, the outer rotor includes a rotor core and a plurality of permanent magnets, wherein the plurality of permanent magnets are fixed on the rotor core along the circumferential direction of the rotor core, and form a rotor pole pair number P. r , the number of pole pairs formed by the armature winding is P s , the number of the stator modulation teeth is N s ; Among them, N s =P r +P s .

[0033] A wind turbine generator set is characterized in that it comprises the split-tooth permanent magnet vernier motor as described above.

[0034] In this solution, through this setting, the split-tooth permanent magnet vernier motor as described above is used in the wind turbine generator set to avoid core saturation of the split-tooth permanent magnet vernier motor in the wind turbine generator set, and avoid the problems of excessive weight and difficulty in heat dissipation.

[0035] The positive progress effect of the present invention is:

[0036] In this split-tooth permanent magnet vernier motor, the armature winding of the inner stator is arranged around the corresponding stator armature teeth. When energized, the current in the armature winding generates a corresponding magnetic field that interacts with the magnetic field of the outer rotor during rotation, thereby generating torque to drive the motor to rotate. In this process, the stator armature teeth are used to split pairs of stator modulation teeth toward the outer rotor side as modulation poles, reducing the number of slots in the armature winding and solving the problem of large end winding span. At the same time, a first modulation slot can be formed between the pairs of stator modulation teeth, and a chamfer is provided at the bottom edge of the first modulation slot, which is not only beneficial to the manufacturing process, but also can widen the magnetic circuit at this position, thereby making the magnetic density distribution of the stator core at this position relatively sparse, alleviating the saturation degree of the stator core, avoiding the stator armature teeth being designed with a wider size, thereby increasing the overall weight of the motor, and the first modulation slot can also be used to reduce the overall weight of the motor, which helps to reduce the difficulty of heat dissipation of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is an overall cross-sectional schematic diagram of a split-tooth permanent magnet vernier motor according to an embodiment of the present invention;

[0038] Figure 2 A schematic cross-sectional view of a unit motor in a split-tooth permanent magnet vernier motor according to an embodiment of the present invention;

[0039] Figure 3 It is a partial cross-sectional schematic diagram of an inner stator in a unit motor in one embodiment of the present invention.

[0040] Description of reference numerals:

[0041] Split tooth permanent magnet vernier motor 1

[0042] Unit motor 10

[0043] Stator armature teeth 211

[0044] Tooth weight reduction groove 2111

[0045] Armature slot 2112

[0046] Stator modulation tooth 212

[0047] First modulation tank 2121

[0048] Second modulation tank 2122

[0049] Chamfer 2123

[0050] Stator yoke 213

[0051] Yoke weight reduction groove 2131

[0052] Armature winding 22

[0053] Outer rotor 30

[0054] Rotor core 31

[0055] Permanent magnet 32 DETAILED DESCRIPTION

[0056] The following describes in detail embodiments of the present invention, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0057] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "circumferential", "radial", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0058] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0059] The present invention discloses a split-tooth permanent magnet vernier motor 1, such as Figure 1 As shown, the split-tooth permanent magnet vernier motor 1 includes a plurality of unit motors 10 , and the structures of these unit motors 10 are the same. These unit motors 10 are arranged in a circumferential array to form the entire split-tooth permanent magnet vernier motor 1 .

[0060] like Figure 2 As shown, each unit motor 10 includes an inner stator and an outer rotor 30 arranged from the inside out, with an air gap provided between the inner stator and the outer rotor 30. Each outer rotor 30 includes a rotor core 31 and a plurality of permanent magnets 32. The plurality of permanent magnets 32 are evenly fixed on the rotor core 31 along the circumferential direction of the rotor core 31, forming a rotor pole pair number P. r The structure of the permanent magnet 32 ​​can be surface-mounted, internal, spoke-type, Halbach array, or alternating pole. The permanent magnet 32 ​​can be made of permanent magnet materials such as neodymium iron boron and samarium cobalt. Each inner stator includes several pairs of stator cores and armature windings 22. The stator cores further include stator armature teeth 211, stator modulating teeth 212, and stator iron yokes 213. The armature windings 22 are arranged around the corresponding stator armature teeth 211. The number of pole pairs formed by the armature windings 22 is P. s , and the number of stator modulation teeth 212 is N s ; Rotor pole pair number P r The number of pole pairs formed by the armature winding 22 is P s and the number N of stator modulation teeth 212 s The relationship between them satisfies: N s =Pr +P s .

[0061] like Figure 2 and Figure 3 As shown, the stator armature teeth 211 are split into pairs of stator modulation teeth 212 along the radial direction toward the outer rotor 30 side, and a first modulation slot 2121 is formed between the pairs of stator modulation teeth 212. The first modulation slot 2121 is provided with a chamfer 2123 at the bottom edge of the slot. Figure 2 and Figure 3 As shown, a pair of stator modulation teeth 212 are formed on the outer surface of the stator armature tooth 211, and the space between the two stator modulation teeth 212 is used to form a first modulation slot 2121. Therefore, the first modulation slot 2121 is a groove structure with a certain depth, and the edge position of the bottom of the slot is the connecting corner position of the stator modulation tooth 212 and the corresponding stator armature tooth 211. A chamfer 2123 is provided at this position. It can be understood that the chamfer 2123 includes a straight inclined chamfer 2123, an arc chamfer 2123 or other types of chamfers 2123. The setting of the chamfer 2123 can increase the width dimension of the above-mentioned corner position to widen the magnetic circuit at the corner position. The straight inclined chamfer 2123 used in this embodiment has an inclination angle α and an oblique angle distance d. r However, in other alternative embodiments, the chamfer 2123 may be another type of chamfer 2123 .

[0062] Through the above-mentioned arrangement, when the split-tooth permanent magnet vernier motor 1 is energized, the current in the armature winding 22 generates a corresponding magnetic field that interacts with the magnetic field of the outer rotor 30 during rotation, thereby generating torque to cause the motor to rotate. In this process, the stator armature teeth 211 are used to split pairs of stator modulation teeth 212 toward one side of the outer rotor 30 as modulation poles, thereby reducing the number of slots in the armature winding 22 and solving the problem of large end winding span. At the same time, a first modulation slot 2121 can be formed between the pairs of stator modulation teeth 212, and a chamfer 2123 is provided at the bottom edge of the first modulation slot 2121, which is not only beneficial to the manufacturing process, but also can widen the magnetic circuit at this position, thereby making the magnetic density distribution of the stator core at this position relatively sparse, alleviating the saturation degree of the stator core, avoiding the stator armature teeth 211 being designed with a wider size, thereby increasing the overall weight of the motor, and can also use the first modulation slot 2121 to reduce the overall weight of the motor, which helps to reduce the difficulty of heat dissipation of the motor.

[0063] like Figure 2 and Figure 3As shown, the inner stator has armature slots 2112 between the stator armature teeth 211 of adjacent stator cores. The armature winding 22 is specifically arranged in the armature slots 2112 around the corresponding stator armature teeth 211. In addition, along the circumferential direction of the stator core, the width of the stator modulated tooth 212 is d1, and the minimum distance between the chamfer 2123 and the adjacent armature slot 2112 is d2; wherein d1<d2<1.2d1. By setting the minimum distance between the chamfer 2123 provided in the first modulation slot 2121 and the adjacent armature slot 2112 to a certain proportion of the width of the stator modulation tooth 212, the chamfer 2123 is used to widen the magnetic circuit of the first modulation slot 2121 at the edge of its slot bottom, so that the magnetic circuit corresponding to the stator armature tooth 211 can be evenly transitioned to the stator modulation tooth 212. While reducing the overall weight of the motor, the magnetic flux density distribution of the stator core is avoided from varying too much, thereby alleviating the saturation of the stator core as much as possible.

[0064] In addition, in the radial direction of the stator core, the extension dimension of the stator modulation tooth 212 is S1, the depth dimension of the first modulation slot 2121 is S2, and the outer edge line of each modulation tooth close to the rotor side is an arc, and the corresponding radius of the arc is the stator outer diameter R so , and the bottom radius of each armature slot 2112 is R sbo , the top radius of each armature slot 2112 is R sto , where S1 = R so -R sto , 0.48S1<S2<0.56S1. By setting the depth of the first modulation slot 2121 to a certain ratio of the extended dimension of the stator modulation tooth 212, the depth of the first modulation slot 2121 is prevented from being too deep, resulting in the distance between its slot bottom and the corresponding armature slot 2112 being too small. As a result, the magnetic flux density distribution at this position of the stator core is relatively dense.

[0065] like Figure 2 and Figure 3 As shown, in adjacent stator cores, second modulation slots 2122 are provided between adjacent stator modulation teeth 212. The positions of the second modulation slots 2122 correspond to the armature teeth between the same stator modulation teeth 212, and the second modulation slots 2122 are connected to the corresponding armature slots 2112. By providing the second modulation slots 2122 at positions corresponding to the armature slots 2112 on the stator core and connecting the second modulation slots 2122 to the corresponding armature slots 2112, it is more convenient to surround the armature winding 22 around the periphery of the stator armature teeth 211. The second modulation slots 2122 can also be used to further reduce the overall weight of the motor and help reduce the difficulty of heat dissipation.

[0066] Furthermore, in each stator core, the paired stator modulating teeth 212 split from the stator armature teeth 211 are symmetrically arranged about the central axis of the same stator armature tooth 211, thereby achieving a more uniform and symmetrical magnetic flux distribution within the stator core, which is more conducive to stable motor operation. However, in alternative embodiments, the paired stator modulating teeth 212 split from the stator armature teeth 211 in each stator core may not be symmetrically arranged about the central axis of the same stator armature tooth 211, as long as the first modulation slot 2121 is formed between the paired stator modulating teeth 212.

[0067] like Figure 2 and Figure 3 As shown, the central angle corresponding to the stator core is θ1, the central angle corresponding to the span between the paired stator modulation teeth 212 is θ2, and the outer edge surface of the stator modulation teeth 212 facing the outer rotor 30 is an arc surface, and the central angle corresponding to the arc surface is θ3; wherein, 0.75θ1<θ2<0.82θ1, 0.45θ2<2θ3<0.55θ2. By setting the central angle corresponding to the span between the paired stator modulating teeth 212 to a certain proportion of the central angle corresponding to the stator core, the spacing between adjacent stator modulating teeth 212 in adjacent stator cores is prevented from being too large or too small, thereby reducing the overall weight of the motor as much as possible and improving the overall heat dissipation performance of the motor without damaging the original performance of the motor. At the same time, the central angle corresponding to the outer edge surface of each stator modulating tooth 212 is set to a certain proportion of the central angle corresponding to the span between the paired stator modulating teeth 212, thereby preventing the outer edge surface of each stator modulating tooth 212 from having a relatively small size, thereby narrowing the magnetic circuit at its outer edge surface position, making the magnetic flux density distribution at that location more dense, and in turn aggravating the saturation degree of the stator core.

[0068] like Figure 2 and Figure 3 As shown, a tooth weight-reducing slot 2111 is formed on the stator armature tooth 211 in the stator core at the end portion near the outer rotor 30. The tooth weight-reducing slot 2111 is connected to a first modulation slot 2121 formed on the same stator armature tooth 211. This arrangement further reduces the amount of stator core required, thereby further reducing the overall weight of the motor and reducing the difficulty of heat dissipation. Furthermore, because the magnetic flux distribution of the stator armature tooth 211 at its symmetrical center axis is relatively sparse, the position of the tooth weight-reducing slot 2111 is adjusted so that it communicates with the corresponding first modulation slot 2121 to form a "T"-shaped slot. This "T"-shaped slot is symmetrical, and the symmetry axis of the "T"-shaped slot coincides with the center axis of the stator armature tooth 211. This arrangement minimizes the impact of the magnetic flux distribution in the stator armature tooth 211 while utilizing the tooth weight-reducing slot 2111 to reduce the overall weight of the motor.

[0069] However, in other alternative embodiments, the "T"-shaped slot formed by the tooth weight-reducing slot 2111 and the corresponding first modulation slot 2121 is not necessarily required to be a symmetrical structure. Even if it is a symmetrical structure, its symmetry axis is not necessarily required to coincide with the central axis of the stator armature tooth 211.

[0070] As described above, the stator core of the inner stator also includes a stator yoke 213, which is arranged on the side of the stator armature teeth 211 away from the outer rotor 30 in its radial direction, so as to form a complete stator core by combining the stator yoke 213 with the stator armature teeth 211 and the stator modulation teeth 212. Adjacent stator armature teeth 211 are connected through the stator yoke 213 to ensure that the magnetic lines of force in adjacent stator armature teeth 211 can be transmitted through the stator yoke 213. Since the inner side wall of the stator yoke 213 away from the stator armature teeth 211 is at a position corresponding to the tooth weight reduction groove 2111, the magnetic density distribution is relatively sparse. Therefore, in this application, in combination with Figure 2 and Figure 3 As shown, a yoke weight-reducing groove 2131 is provided on the inner side wall of the stator yoke 213 away from the stator armature teeth 211, corresponding to the tooth weight-reducing groove 2111. While utilizing the yoke weight-reducing groove 2131 to reduce the overall weight of the motor, the magnetic flux distribution in the stator yoke 213 is avoided as much as possible.

[0071] Specifically, the cross-sectional shape of the yoke weight-reducing groove 2131 is semicircular, and the center of the semicircle is located at the intersection of the central axis of the corresponding stator armature tooth 211 and the arc of the inner side wall of the stator iron yoke 213. Through this arrangement, the arrangement of the yoke weight-reducing groove 2131 is made more regular, so as to avoid the uneven arrangement positions thereof causing the structure of the stator core to become more complicated and causing excessive impact on the magnetic flux distribution in the stator core. However, in other alternative embodiments, the cross-sectional shape of the yoke weight-reducing groove 2131 can also adopt other shapes, such as a semi-polygon or a rectangle, etc.

[0072] At the same time, the minimum distance between the bottom of the tooth weight-reducing groove 2111 and the corresponding yoke weight-reducing groove 2131 is d3, and the depth dimension of the tooth weight-reducing groove 2111 is S3, where 0.75d3 < S3 < 0.85d3. By setting the depth dimension of the tooth weight-reducing groove 2111 to a certain ratio of the minimum distance between the bottom of the tooth weight-reducing groove 2111 and the corresponding yoke weight-reducing groove 2131, the depth of the tooth weight-reducing groove 2111 is prevented from being too deep or the minimum distance between the tooth weight-reducing groove 2111 and the corresponding yoke weight-reducing groove 2131 being too small, which would structurally affect the stability of the motor operation and significantly affect the magnetic flux distribution on the stator armature teeth 211, thereby reducing the motor efficiency.

[0073] In the circumferential direction of the stator core, the width of the tooth weight-reducing slot 2111 is d6, the width of the stator armature tooth 211 minus the width of the tooth weight-reducing slot 2111 is d4, and the minimum distance between the yoke weight-reducing slot 2131 and the bottom of the adjacent armature slot 2112 is d5; where 0.45d4 < d5 < 0.6d4. This arrangement prevents the minimum distance between the yoke weight-reducing slot 2131 and the bottom of the adjacent armature slot 2112 from being too small, thereby preventing the magnetic circuit at that location from being too narrow, and thus preventing the magnetic flux density distribution from being too dense.

[0074] This embodiment also involves a wind turbine generator set, which includes the split-tooth permanent magnet vernier motor 1 as described above, so as to avoid the core saturation of the split-tooth permanent magnet vernier motor 1 in the wind turbine generator set, and avoid the problems of excessive weight and difficulty in heat dissipation.

[0075] A preferred specific implementation is provided below to further describe the split-tooth permanent magnet vernier motor 1 in the above embodiment.

[0076] A split-tooth permanent magnet vernier motor 1, such as Figure 1 As shown, the whole machine includes nine unit motors 10 with identical structures arranged uniformly along the circumference. Each unit motor 10 includes an inner stator and an outer rotor 30 arranged from the inside to the outside, with an air gap provided between the inner stator and the outer rotor 30. Each unit motor 10 includes nine armature slots 2112, nine first modulation slots 2121 and nine second modulation slots 2122. The number of stator modulation teeth 212 is N. s = 18, the number of rotor pole pairs of the unit motor 10 is Pr = 14, and the number of stator armature pole pairs formed by the armature winding 22 is Ps = 4. The number of rotor pole pairs, the number of stator armature pole pairs and the number of modulation teeth of the unit motor 10 satisfy: Ps + Pr = Ns.

[0077] like Figure 2 and Figure 3 As shown, the stator in the unit motor 10 includes a stator core and an armature winding 22. The stator core is made of laminated silicon steel sheets. The stator core includes stator armature teeth 211, stator modulation teeth 212 and a stator iron yoke 213. The stator armature teeth 211 are provided with tooth weight-reducing slots 2111 and armature slots 2112. The stator modulation teeth 212 are provided with first modulation slots 2121 and second modulation slots 2122. The stator iron yoke 213 is provided with a yoke weight-reducing slot 2131.

[0078] The inner edge of the stator yoke 213 is bounded by the arc of the stator inner diameter (Rsi = 2945 mm) and the edge of the yoke weight-reducing slot 2131. The yoke weight-reducing slot 2131 is located on the stator yoke 213, close to the stator inner diameter. Nine semicircular yoke weight-reducing slots 2131 are evenly spaced along the circumference. Specifically, the center of the yoke weight-reducing slot 2131 is located at the intersection of the geometric axis of the stator armature tooth 211 and the arc of the stator yoke 213 inner diameter. The semicircular radius of the corresponding cross-section of the yoke weight-reducing slot 2131 is R = 40 mm. The minimum distance between the yoke weight-reducing slot 2131 and the bottom of the corresponding armature slot 2112 is d3 = 78.7 mm. The width of the stator armature tooth 211 minus the width of the tooth weight-reducing slot 2111 is d4 = 139.8 mm.

[0079] like Figure 2 and Figure 3 As shown, the outer side of the stator yoke 213 is an arc structure, and the stator teeth extending radially outward from the stator yoke 213 form nine stator armature teeth 211. The central angle of the span of the stator armature teeth 211 is θ4 = 3.067°, and the central angle corresponding to the entire stator core is θ1 = 4.444°; wherein θ4 / θ1 = 0.69.

[0080] The space between adjacent stator armature teeth 211 of the stator core is the armature slot 2112. The armature winding 22 is placed in the armature slot 2112 to form an armature magnetic field with a pole pair number of 4. The bottom radius of the armature slot 2112 is R sbo =3025mm, the top radius of the armature slot 2112 is R sto =3125mm, groove depth is R sbo -R sto =100mm.

[0081] The stator armature tooth 211 is split into two stator modulating teeth 212 along the radial direction toward the rotor side. The outer edge line of each stator modulating tooth 212 close to the rotor side is an arc with a radius of the stator outer diameter R. so =3181mm, the corresponding central angle is θ3 = 0.895°, the span between the two modulation teeth near the outer edge of the slot corresponds to a central angle of θ2 = 3.51°, and θ2 / θ1 = 0.79, 2θ3 / θ2 = 0.51. Furthermore, the width of the first modulation slot 2121 between the two stator modulation teeth 212 corresponds to a central angle of θ3-2θ4 = 1.72°, the slot depth is S2 = 31mm, and the extended dimension of the stator modulation tooth 212 in the radial direction of the stator core is S1, where S1 = R so -R sto , S2=0.55S1.

[0082] The bottom corner of the first modulation slot 2121 on the stator armature tooth 211 is chamfered 2123. The angle of chamfer 2123 is α = 45°, and the bevel distance is dr = 17 mm. This chamfering 2123 not only facilitates manufacturing but also increases the thickness of the iron core at the junction of the stator modulation tooth 212 and the stator armature tooth 211, thereby reducing the iron core saturation at this location. Furthermore, the minimum distance between the bottom chamfer 2123 of the first modulation slot 2121 on the stator armature tooth 211 and the top of the adjacent armature slot 2112 is d2 = 31 mm, where d2 is 1.107 times the width d1 of the stator modulation tooth 212.

[0083] A rectangular tooth-weight reduction slot 2111 with a width d6 of 38 mm and a height S3 of 71.4 mm is located at the end of the stator armature tooth 211 near the outer rotor 30. This slot 2111 connects to the first modulation slot 2121 between two stator modulation teeth 212 on the same stator armature tooth 211, forming a single T-shaped slot. This T-shaped slot coincides with the geometric axes of both the stator armature tooth 211 and the yoke-weight reduction slot 2131 below it. The width d6 of the tooth-weight reduction slot 2111 is 0.398 times the width of the first modulation slot 2121. The minimum distance d3 from the bottom of the tooth-weight reduction slot 2111 to the corresponding yoke-weight reduction slot 2131 is 90 mm, and S3 / d3 is 0.793.

[0084] After adopting the above-mentioned structure and size design, the core saturation at the connection between the stator modulating teeth 212 and the stator armature teeth 211 is reduced, which helps to improve the electromagnetic power. Although the stator core uses less core due to the setting of the weight-reducing slots, the core saturation at the slotted position is increased, but because the magnetic lines of force at the original slotted position are relatively sparse and the magnetic density is lower than the saturation magnetic density, the increase in magnetic density at other positions caused by the slotting is not large. Moreover, since the core usage is reduced after the slotting, the increase in the loss in the stator core due to weight reduction is small. Overall, the weight of the stator core is reduced from 43.5 tons to 38.4 tons, a weight reduction of 11.7%, while the increase in core loss due to weight reduction is only 1.7kW. In addition, due to the reduction in core saturation at the connection between the stator modulating teeth 212 and the stator armature teeth 211, its electromagnetic power and grid-connected power are increased by 2.2% and 2.6% respectively, and the motor efficiency is increased by 0.2%.

[0085] Although specific embodiments of the present invention have been described above, those skilled in the art will appreciate that these are merely illustrative and that the scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, and such changes and modifications are intended to fall within the scope of the present invention.

Claims

1. A wind turbine generator comprising a split-tooth permanent magnet vernier motor, wherein the split-tooth permanent magnet vernier motor comprises an inner stator and an outer rotor, an air gap being provided between the inner stator and the outer rotor, and characterized in that: The inner stator includes a plurality of stator cores and armature windings arranged in pairs. The stator cores include stator armature teeth and stator modulation teeth. The armature windings are arranged around the corresponding stator armature teeth. The stator armature teeth are split into pairs of stator modulation teeth along their radial direction toward the outer rotor side. First modulation slots are formed between the pairs of stator modulation teeth. The first modulation slots are chamfered at the bottom edges of the slots. The outer rotor includes a rotor core and a plurality of permanent magnets, wherein the plurality of permanent magnets are fixed on the rotor core along the circumferential direction of the rotor core and form a rotor pole pair number P. r , the number of pole pairs formed by the armature winding is P s , the number of the stator modulation teeth is N s ; Among them, N s =P r +P s ; An armature slot is provided between the stator armature teeth of adjacent stator cores, and the armature winding is arranged around the corresponding stator armature teeth in the armature slot; In the circumferential direction of the stator core, the width of the stator modulation tooth is d1, and the minimum distance between the chamfer and the adjacent armature slot is d2; wherein d1<d2<1.2d1.

2. The wind turbine according to claim 1, wherein: In the radial direction of the stator core, the extension dimension of the stator modulation tooth is S1, and the depth dimension of the first modulation slot is S2; wherein, 0.48S1<S2<0.56S1.

3. The wind turbine according to claim 1 or 2, characterized in that: In adjacent stator cores, second modulation slots are provided between adjacent stator modulation teeth. Positions of the second modulation slots correspond to the armature slots between the same stator modulation teeth, and the second modulation slots are connected to the corresponding armature slots.

4. The wind turbine according to claim 1, wherein: The pairs of stator modulation teeth split from the stator armature teeth are symmetrically arranged around the central axis of the same stator armature tooth.

5. The wind turbine according to claim 4, wherein: The central angle corresponding to the stator core is θ1, the central angle corresponding to the span between the paired stator modulation teeth is θ2, the outer edge surfaces of the stator modulation teeth facing the outer rotor are all arc surfaces, and the central angle corresponding to the arc surfaces is θ3; among them, 0.75θ1<θ2<0.82θ1, 0.45θ2<2θ3<0.55θ2.

6. The wind turbine according to any one of claims 1 to 5, characterized in that: A tooth weight reduction groove is further provided on the stator armature tooth at an end portion on one side close to the outer rotor. The tooth weight reduction groove is communicated with the first modulation groove formed on the same stator armature tooth.

7. The wind turbine according to claim 6, wherein: The tooth weight reduction groove and the corresponding first modulation groove cooperate with each other to form a "T"-shaped groove. The "T"-shaped groove is a symmetrical structure, and the symmetry axis of the "T"-shaped groove coincides with the central axis of the stator armature tooth.

8. The wind turbine according to claim 6, wherein: The split-tooth permanent magnet vernier motor is formed by a plurality of unit motors of the same structure arranged in a circumferential array. The unit motor includes the inner stator and the outer rotor. The stator core also includes a stator yoke. The stator yoke is arranged on the side of the stator armature teeth away from the outer rotor along its radial direction, and a yoke weight-reducing groove is provided on the inner side wall of the stator yoke away from the stator armature teeth corresponding to the tooth weight-reducing groove.

9. The wind turbine according to claim 8, wherein: The cross-section of the yoke weight reduction groove is semicircular, and the center of the semicircle is located at the intersection of the central axis of the stator armature tooth and the arc of the inner side wall of the stator iron yoke; And / or, the minimum distance between the bottom of the tooth weight-reducing groove and the corresponding yoke weight-reducing groove is d3, and the depth dimension of the tooth weight-reducing groove is S3, wherein 0.75d3<S3<0.85d3.

10. The wind turbine according to claim 8, wherein: An armature slot is provided between the stator armature teeth of adjacent stator cores, and the armature winding is arranged around the corresponding stator armature teeth in the armature slot; In the circumferential direction of the stator core, the width of the stator armature tooth minus the width of the tooth weight-reducing slot is d4, and the minimum distance between the yoke weight-reducing slot and the bottom of the adjacent armature slot is d5; wherein 0.45d4<d5<0.6d4.

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