Tooth splicing type high-voltage and high-speed motor stator and design method

Abstract

The invention discloses a tooth splicing type high-voltage and high-speed motor stator and a design method, the tooth splicing type high-voltage and high-speed motor stator comprises a stator yoke and stator teeth, the stator teeth are uniformly distributed along the inner circumference of the stator yoke, and a stator slot for installing a winding is formed between adjacent stator teeth; the stator teeth are of an axisymmetric structure, the side edge of each stator tooth comprises a first contour molded line, a second contour molded line, a third contour molded line and a fourth contour molded line which are sequentially arranged in the radial direction of the stator, and the first contour molded lines of the adjacent stator teeth form winding installation areas. According to the invention, the stator teeth are designed to be detachable through the splicing structure, the line insertion of the formed winding can be smoothly carried out in the winding installation area formed by the first contour molded line, the groove width of the customized teeth can be ensured, and the stator teeth can be conveniently inserted in the winding installation area formed by the first contour molded line. The cogging torque is reduced, and the rotor eddy current loss of the motor is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of high-speed motors, and in particular to a spliced-gear high-voltage high-speed motor stator and a design method thereof. Background Art

[0002] With the country's vigorous promotion of energy conservation and emission reduction, high-speed motors are increasingly widely used in aerospace, industrial and agricultural production, and various fields of daily life due to their many significant advantages such as small size, light weight, less consumables, and high power density. For example, the current more mature magnetic levitation high-speed motor, with its advanced suspension technology, greatly reduces friction loss during operation and improves the efficiency and stability of the motor; the air suspension high-speed motor uses the support of gas to achieve low noise and low vibration under high-speed operation.

[0003] However, the current high-speed motors generally use 380V power supply due to their relatively small power. However, with the increasing demand for motor power in various fields, 380V power supply can no longer meet the actual needs of motors. In this context, the development of high-voltage and high-speed motors is imminent. The research and development of high-voltage and high-speed motors can not only meet the growing power demand, but also further improve the efficiency and performance of motors, providing a more powerful power source to promote the development of various industries.

[0004] For high-speed motors, the speed is relatively high. Due to the limitation of the rotor material strength, the outer diameter of the rotor should not be too large to ensure that the linear speed of the rotor is within a certain range. At the same time, under the premise of ensuring the air gap length, the inner diameter of the stator is usually smaller. When the number of stator slots is constant, when the inner diameter of the stator is smaller, the stator tooth pitch is also smaller. At this time, in order to ensure the mechanical strength of the stator teeth at the slot, the stator slot width is also smaller. In ordinary high-speed motors, the winding is usually a low-voltage loose-embedded winding, and a smaller slot width can also meet the wire embedding requirements. For high-voltage motors, the withstand voltage level of this loose-embedded winding is relatively low and cannot withstand high voltage. Therefore, in conventional high-voltage motors, formed windings are used. This type of winding is pre-formed and has specific requirements for the slot width. The purpose is to be able to meet the wire embedding operation of the formed winding.

[0005] Therefore, in the field of high-voltage and high-speed motors, due to the limitation of the inner diameter of the stator, the width of the stator slot is small, so the wire embedding of the formed winding has also become a difficulty. Moreover, the closer the winding is placed to the slot, the greater the AC loss of the winding. In addition, the frequency of high-speed motors is high, and the formed winding uses flat copper wire with a large wire diameter and close to the slot, which will greatly increase the AC loss of the copper wire, and then significantly increase the heat generated by the motor, making it difficult to meet the heat dissipation requirements. This series of problems makes the application of conventional formed windings in high-speed motors face many challenges. Summary of the invention

[0006] Technical purpose: In view of the above-mentioned deficiencies of the existing high-speed motor stators, the present invention discloses a spliced-gear high-voltage high-speed motor stator and a design method.

[0007] Technical solution: To achieve the above technical objectives, the present invention adopts the following technical solution:

[0008] A spliced-tooth high-voltage and high-speed motor stator comprises a stator yoke and stator teeth, wherein the stator teeth are evenly distributed along the inner circumference of the stator yoke, and stator slots for installing windings are formed between adjacent stator teeth; the stator teeth are of an axisymmetric structure, and the side edges of the stator teeth comprise a first contour line, a second contour line, a third contour line and a fourth contour line which are sequentially arranged along the radial direction of the stator, the first contour lines of adjacent stator teeth form a winding installation area, the second contour line is inclined toward the inner side of the corresponding winding installation area to form a tapered ventilation area with a gradually decreasing width, the third contour line performs a transition between the second contour line and the fourth contour line, and the stator teeth form a notch through the fourth contour line; along the length direction of the stator teeth, a splicing structure is adopted at the junction of the first contour line and the second contour line.

[0009] Preferably, the splicing structure of the present invention separates the stator teeth into outer stator teeth and inner stator teeth, and the mating surfaces of the outer stator teeth and the inner stator teeth are connected via dovetail grooves and corresponding clamping blocks.

[0010] Preferably, the outer stator teeth of the present invention are integrally formed with the stator yoke.

[0011] Preferably, the first contour line of the present invention and the center line of the corresponding positioning groove are arranged parallel to each other to form a rectangular winding installation area.

[0012] Preferably, in the present invention, the second contour line of the same stator tooth and the symmetry center line of the corresponding stator tooth are arranged parallel to each other.

[0013] The present invention discloses a design method based on the above-mentioned spliced ​​gear type high-voltage high-speed motor stator, comprising the steps of:

[0014] S01. Determine the slot width of the stator slot according to the proportion of the rotor eddy current loss and the winding AC loss of the motor;

[0015] S02, calculating the stator tooth width and the stator yoke height according to the electromagnetic parameters of the motor stator;

[0016] S03. Calculate the geometric parameters of the stator according to the geometric shape formed by the side profile of the stator teeth to determine the final stator parameters.

[0017] Preferably, in step S02 of the present invention, the process of calculating the stator tooth width and the stator yoke height includes:

[0018] S021. Assume that the air gap flux within one tooth pitch of the stator enters the stator teeth completely; calculate the stator tooth width Where t1 is the pitch of the inner stator teeth, D i1 is the inner diameter of the stator; Z1 is the number of slots; B δ is the maximum value of air gap magnetic density; B t1 is the stator tooth flux density, which is designed near the knee point according to the magnetization curve of the silicon steel sheet; K Fe is the core stacking coefficient;

[0019] S022. After passing through the stator teeth, the magnetic flux of each pole enters the stator yoke in two ways. The magnetic flux of the yoke is half of the magnetic flux of each pole, and the calculated height of the outer stator yoke is obtained: τ is the pole distance, p is the number of pole pairs; α′ p To calculate the polar arc coefficient; B j1 is the magnetic flux density of the outer stator yoke.

[0020] Preferably, in step S03 of the present invention, when calculating based on the geometric shape formed by the side profile of the stator teeth, the width of the corresponding area along the circumferential direction of the stator is equivalent to the length of the arc with the center of the stator as the center for calculation.

[0021] Beneficial effects: The spliced-gear high-voltage high-speed motor stator and design method disclosed in the present invention have the following beneficial effects:

[0022] 1. The present invention designs the stator teeth to be detachable through a splicing structure, and can smoothly embed the wire of the formed winding in the winding installation area formed by the first contour line. At the same time, the slot width of the stator teeth can be guaranteed, the tooth slot torque can be reduced, and the rotor eddy current loss of the motor can be reduced.

[0023] 2. The present invention forms a conical ventilation area through the second contour line, and the formed winding can be far away from the stator slot, which is beneficial to reducing the AC loss of the motor winding and improving the efficiency of the motor. At the same time, a ventilation duct is reserved to increase the ventilation area, which is beneficial to the cooling and heat dissipation of the motor.

[0024] 3. The first contour line of the present invention is arranged parallel to the center line of the stator slot to form a winding installation area, which is conducive to the placement of the formed winding and increases the slot fill rate of the motor.

[0025] 4. The second contour line of the present invention is arranged parallel to the symmetric center line of the stator teeth, forming a conical ventilation area while making the width of the inner stator teeth uniform, thereby ensuring the overall structural strength of the stator teeth. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

[0027] Figure 1 This is the overall structure diagram of the stator of the present invention;

[0028] Figure 2 This is a schematic diagram of the stator tooth structure of the present invention; Figure 3 This is a schematic diagram of stator parameter marking of the present invention;

[0029] Among them, 1-stator yoke, 2-stator teeth, 3-stator slots, 4-first contour line, 5-second contour line, 6-third contour line, 7-fourth contour line, 8-winding installation area, 9-conical ventilation area, 10-outer stator teeth, 11-inner stator teeth, 12-dovetail slots. DETAILED DESCRIPTION

[0030] Reference will now be made in detail to embodiments of the present disclosure, one or more examples of which are set forth herein below. Each embodiment and example is provided by way of explanation of the apparatus, composition and materials of the present disclosure, rather than limitation. On the contrary, the following description provides a convenient illustration of an exemplary embodiment for implementing the present disclosure. In fact, it will be clear to those skilled in the art that various modifications and variations may be made in the teachings of the present disclosure without departing from the scope or spirit of the present disclosure.

[0031] like Figure 1 and Figure 2 As shown, the present invention discloses a spliced-tooth high-voltage and high-speed motor stator, comprising a stator yoke 1 and stator teeth 2, wherein the stator teeth 2 are evenly distributed along the inner circumference of the stator yoke 1, and stator slots 3 for installing windings are formed between adjacent stator teeth 2; the stator teeth 2 are of an axisymmetric structure, and the side edges of the stator teeth 2 include a first contour line 4, a second contour line 5, a third contour line 6 and a fourth contour line 7 sequentially arranged along the radial direction of the stator, the first contour lines 4 of adjacent stator teeth 2 form a winding installation area 8, the second contour line 5 is inclined toward the inner side of the corresponding winding installation area 8 to form a tapered ventilation area 9 with a gradually decreasing width, the third contour line 6 performs a transition between the second contour line 5 and the fourth contour line 7, and the stator teeth 2 form a notch through the fourth contour line 7; along the length direction of the stator teeth 2, a splicing structure is adopted at the junction of the first contour line 4 and the second contour line 5.

[0032] The present invention divides the stator teeth 2 into outer stator teeth 10 and inner stator teeth 11 through a splicing structure. The mating surfaces of the outer stator teeth 10 and the inner stator teeth 11 are connected through the dovetail grooves 12 and corresponding blocks. When the formed winding is installed, the formed winding is away from the notch, which is beneficial to reducing the AC loss of the motor winding and improving the efficiency of the motor; it is not affected by the notch size, reduces the difficulty of installation, and can reduce the notch width to reduce the tooth slot torque and reduce the rotor eddy current loss of the motor.

[0033] In order to ensure the mechanical strength of the stator teeth, the outer stator teeth 10 of the present invention are integrally formed with the stator yoke 1; the first contour line 4 and the center line of the corresponding positioning slot 3 are arranged parallel to each other to form a rectangular winding installation area 8, which is conducive to the installation of the molded winding and can improve the slot fill rate; the second contour line 5 of the same stator tooth 2 and the corresponding stator tooth 2 The symmetrical center line is arranged parallel to each other, which can not only form a stator slot 3 that meets the requirements, but also ensure that the structural strength of the radial parts of the inner stator tooth 10 is consistent, thereby improving the bearing capacity.

[0034] The present invention discloses a design method based on the above-mentioned spliced ​​gear type high-voltage high-speed motor stator, comprising the steps of:

[0035] S01. Determine the slot width of the stator slot according to the proportion of the rotor eddy current loss and the winding AC loss of the motor;

[0036] There are two main aspects that affect the rotor eddy current loss: on the one hand, the slot width affects the amplitude of the stator current spatial harmonics; on the other hand, the stator slot width affects the air gap permeability, resulting in a depression in the air gap magnetic flux density spatial distribution, causing the magnetic field of each part of the rotor to change, causing eddy current loss. As the slot width increases, the magnetic flux density fluctuations of each part of the rotor increase, so the eddy current loss also increases.

[0037] The eddy current loss of the conductor in the slot is proportional to the square of the magnetic flux density, and the magnetic flux density in the motor slot is closely related to the slot size, so the AC loss of the motor winding is also closely related to the slot size. Specifically, the AC loss of the winding will decrease as the slot width increases.

[0038] In the slot width B s0 The determination of needs to comprehensively consider the proportion of rotor eddy current loss and winding AC loss.

[0039] S02, calculating the stator tooth width and the stator yoke height according to the electromagnetic parameters of the motor stator;

[0040] In step S02 of the present invention, the process of calculating the stator tooth width and the stator yoke height includes:

[0041] S021. Assume that the air gap flux within one stator tooth pitch all enters the stator teeth; calculate the stator tooth width b t1 = Where t1 is the pitch of the inner stator teeth, D i1 is the inner diameter of the stator; Z1 is the number of slots; B δ is the maximum value of air gap magnetic density; B t1 is the stator tooth flux density, which is designed near the knee point according to the magnetization curve of the silicon steel sheet; K Fe is the stator core stacking coefficient;

[0042] S022. After passing through the stator teeth, the magnetic flux of each pole enters the stator yoke in two ways. The magnetic flux of the yoke is half of the magnetic flux of each pole, and the calculated height of the outer stator yoke is obtained: τ is the pole distance, p is the number of pole pairs; α′ p To calculate the polar arc coefficient; B j1 is the magnetic flux density of the outer stator yoke. In order to reduce the iron loss of the yoke, the design time is B j1 Generally slightly lower than B t1 .

[0043] S03. Calculate the geometric parameters of the stator according to the geometric shape formed by the side profile of the stator teeth to determine the final stator parameters.

[0044] In step S03 of the present invention, when calculating based on the geometric shape formed by the side profile of the stator teeth, the width of the corresponding area along the circumferential direction of the stator is equivalent to the length of the arc with the center of the stator as the center. When divided according to the circumference, the width dimension is approximately consistent with the length of the arc at the corresponding position, which can reduce the amount of calculation and reduce the difficulty of stator design.

[0045] When calculating the geometric shape, establish the relationship between the size parameters of each area:

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052] In an embodiment of the present invention, Figure 2As shown, the winding installation area 8 is a rectangular structure with a length of a and a width of b. The relationship between the conductor cross-sectional area S and the slot fill factor f is: S = abf. The diameter of the stator yoke is D1. The widths of the two ends of the outer stator teeth are b. max , b min The length of the second contour line of the inner stator tooth 11 is H s2 , the length of the fourth contour line 7 is H s0 , can be selected according to the mechanical strength requirements to be borne to avoid deformation; the third contour line 6 is a transition between the second contour line 5 and the fourth contour line 7. To ensure structural strength, the inclination angle β is generally 30°; D i1 is the inner diameter of the stator; Z1 is the number of stator slots; H s1 B is the radial length corresponding to the third profile; s1 is the width of the smaller end of the conical ventilation area. According to the combined equations, the corresponding unknown parameters can be calculated: a, b, H s1 、b min , B s1 , H s2 、b max .

[0053] The calculated stator structure needs to be verified for electromagnetic performance. For electromagnetic performance that does not meet the predetermined requirements, the magnetic flux density of the stator teeth and stator yoke, as well as the slot depth and slot width of the stator slots, need to be adjusted based on the verification results and substituted into the calculation again. The design calculation model of the present invention can quickly design the stator structure and ensure that the electromagnetic performance meets the design requirements.

Claims

1. A spliced ​​gear type high voltage high speed motor stator, characterized in that: The invention comprises a stator yoke (1) and stator teeth (2), wherein the stator teeth (2) are evenly distributed along the inner circumference of the stator yoke (1), and stator slots (3) for installing windings are formed between adjacent stator teeth (2); the stator teeth (2) are of an axisymmetric structure, and the side edges of the stator teeth (2) comprise a first contour line (4), a second contour line (5), a third contour line (6) and a fourth contour line (7) which are sequentially arranged along the radial direction of the stator, and the first contour lines of adjacent stator teeth (2) are arranged in a uniform manner. The first contour line (4) forms a winding installation area (8), the second contour line (5) is inclined toward the inner side of the corresponding winding installation area (8) to form a tapered ventilation area (9) with a gradually decreasing width, the third contour line (6) performs a transition between the second contour line (5) and the fourth contour line (7), and the stator tooth (2) forms a notch through the fourth contour line (7); and a splicing structure is adopted at the junction of the first contour line (4) and the second contour line (5) along the length direction of the stator tooth (2).

2. The gear-type high-voltage and high-speed motor stator according to claim 1, characterized in that: The splicing structure separates the stator teeth (2) into outer stator teeth (10) and inner stator teeth (11); the mating surfaces of the outer stator teeth (10) and the inner stator teeth (11) are connected via dovetail grooves (12) and corresponding clamping blocks.

3. The spliced ​​gear type high voltage and high speed motor stator according to claim 2, characterized in that: The outer stator teeth (10) are integrally formed with the stator yoke (1).

4. The spliced ​​gear type high voltage and high speed motor stator according to claim 2, characterized in that: The first contour line (4) and the center line of the corresponding positioning groove (3) are arranged parallel to each other to form a rectangular winding installation area (8).

5. A spliced-gear high-voltage and high-speed motor stator according to claim 2 or 4, characterized in that: The second contour line (5) of the same stator tooth (2) and the symmetry center line of the corresponding stator tooth (2) are arranged parallel to each other.

6. The design method of the spliced ​​gear type high voltage and high speed motor stator according to any one of claim 15, characterized in that: Includes steps: S01. Determine the slot width of the stator slot according to the proportion of the rotor eddy current loss and the winding AC loss of the motor; S02, calculating the stator tooth width and the stator yoke height according to the electromagnetic parameters of the motor stator; S03. Calculate the geometric parameters of the stator according to the geometric shape formed by the side profile of the stator teeth to determine the stator parameters.

7. The design method of the spliced ​​gear type high voltage and high speed motor stator according to claim 6, characterized in that: In step In S02, the process of calculating the stator tooth width and the stator yoke height includes: S021. Assume that the air gap flux within one tooth pitch of the stator enters the stator teeth completely; calculate the stator tooth width Where t1 is the pitch of the inner stator teeth, D i1 is the inner diameter of the stator; Z1 is the number of slots; B δ is the maximum value of air gap magnetic flux density; B t1 is the stator tooth flux density, which is designed near the knee point according to the magnetization curve of the silicon steel sheet; K Fe is the core stacking coefficient; S022. After passing through the stator teeth, the magnetic flux of each pole enters the stator yoke in two ways. The magnetic flux of the yoke is half of the magnetic flux of each pole, and the calculated height of the outer stator yoke is obtained: τ is the pole distance, p is the number of pole pairs; α′ p To calculate the polar arc coefficient; B j1 is the magnetic flux density of the outer stator yoke.

8. The design method of the spliced ​​gear type high voltage and high speed motor stator according to claim 6, characterized in that: In step S03, when calculating based on the geometric shape formed by the side profile of the stator teeth, the width of the corresponding area along the circumferential direction of the stator is equivalent to the length of the arc with the center of the stator as the center for calculation.

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