A method for designing optimal air gap magnetic permeability of a permanent magnet vernier motor and a motor

Abstract

The present invention discloses a method for designing the optimal air gap permeability of a permanent magnet vernier motor, which relates to the technical field of permanent magnet motors. First, the stator teeth are evenly divided to define the torque. T The maximum torque is solved by particle swarm optimization based on the functional relationship between the stator tooth height, stator slot bottom, stator slot top, and stator slot depth at each point. T The present invention also discloses a motor designed using this method, comprising: a motor shaft and a rotor and a stator sequentially sleeved on the outside, wherein the stator teeth, the lower bottom of the stator slot, the upper bottom of the stator slot, and the depth of the stator slot are obtained by this method. Finally, stator equivalent teeth are used instead of stator optimized teeth to effectively improve the design efficiency of this method. The optimal air gap magnetic permeability structure breaks the constraints of the simple tooth structure of traditional motors and can modulate a larger working magnetic field amplitude, so that the motor has a stronger output torque.

Description

Technical Field

[0001] The present invention relates to the technical field of permanent magnet motors, and in particular to a method for designing an optimal air gap permeability of a permanent magnet vernier motor and a motor. Background Art

[0002] As the core power source for industrial manufacturing applications such as compressors, machine tool drives, and material handling, electric motors play a vital role in the performance of industrial equipment. With the continuous advancement of industrial technology, higher requirements are being placed on motor performance, such as torque density, torque ripple, and energy conversion efficiency.

[0003] Torque density has always been a key goal in motor development, crucial for reducing motor size and manufacturing costs. The design of the air gap permeance of a permanent magnet vernier motor directly determines the motor's torque performance. However, traditional air gap permeance design methods rely solely on empirical guidance, making it difficult to further improve torque density. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a permanent magnet vernier motor optimal air gap magnetic permeability design method and motor. The present invention improves the torque density of the motor without increasing any material cost of the motor, so that the motor has a stronger torque output capability.

[0005] The present invention adopts the following technical solutions to solve the above technical problems:

[0006] A method for designing an optimal air gap permeability of a permanent magnet vernier motor according to the present invention comprises the following steps:

[0007] Divide the stator teeth of the motor evenly, define the height of the i-th dividing point on the stator tooth as hi, m is the degree of freedom of the stator tooth, m≥i≥1;

[0008] Define the width of the lower bottom of the stator slot as so, the width of the upper bottom of the stator slot as so1, and the depth of the stator slot as hs;

[0009] With so, so1, hs, and h1, h2, ..., hm as input, a seeking algorithm is adopted and the maximum value of the motor torque T is output to optimize and find the optimal hi, so, so1 and hs, thereby determining the optimal air gap magnetic permeability structure.

[0010] As a further optimization scheme of the method for designing the optimal air gap magnetic permeability of a permanent magnet vernier motor described in the present invention, the stator teeth are divided into m+1 equal parts.

[0011] As a further optimization scheme of the optimal air gap magnetic permeance design method of a permanent magnet vernier motor described in the present invention, reducing the degree of freedom m of the motor stator teeth can improve the air gap magnetic field modulation capability of the magnetic permeance structure without affecting T.

[0012] As a further optimization scheme of the method for designing the optimal air gap magnetic permeability of a permanent magnet vernier motor described in the present invention, the structure of the stator teeth is a structure combining a triangle and a trapezoid.

[0013] As a further optimization scheme for the optimal air gap permeance design method of a permanent magnet vernier motor described in the present invention, a particle swarm optimization algorithm is sought.

[0014] A permanent magnet vernier motor comprises a stator and a rotor, wherein the stator comprises a stator yoke, stator slots and stator teeth, and the rotor comprises permanent magnets, a rotor yoke and a rotating shaft. The permanent magnet vernier motor is designed using the above method, wherein the rotor and the stator are sequentially sleeved on the outer side of the rotating shaft, the outer surface of the permanent magnet is attached to the outer side of the rotor yoke, an air gap is provided between the stator and the rotor, the stator is provided with stator slots along the circumferential direction, and stator teeth are formed between adjacent stator slots. The permanent magnets are magnetized radially, and all permanent magnets are magnetized in the same manner.

[0015] As an optimization method for a permanent magnet vernier motor described in the present invention, both the stator and the rotor are made of ferromagnetic materials.

[0016] A permanent magnet vernier motor is designed using the above method, and the teeth and slots of the motor are arranged in a circular array.

[0017] Compared with the prior art, the present invention adopts the above technical solution and has the following technical effects:

[0018] The present invention breaks the constraints of the simple tooth structure of traditional motors and can design an optimal air gap magnetic permeability structure without increasing any material cost of the motor, thereby ultimately improving the torque output capacity of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the process of the optimal air gap magnetic permeability design method of the present invention.

[0020] Figure 2 This is the overall structure of the permanent magnet vernier motor designed by the present invention.

[0021] Figure 3 The stator tooth structure of the permanent magnet vernier motor designed by the present invention; (a) is before optimization, and (b) is after optimization.

[0022] Figure 4 The stator structure of the permanent magnet vernier motor designed by the present invention.

[0023] Figure 5 The permanent magnet structure of the permanent magnet vernier motor designed by the present invention.

[0024] Figure 6 The permanent magnet vernier motor rotor structure designed by the present invention.

[0025] Figure 7a The present invention is directed to the optimization of the teeth of the permanent magnet vernier motor designed by the present invention.

[0026] Figure 7b This is the equivalent tooth of the permanent magnet vernier motor designed by the present invention.

[0027] Figure 7c This is a comparison chart of the torque performance of the optimized teeth and equivalent teeth of the permanent magnet vernier motor designed by the present invention.

[0028] The reference numerals in the figure are: 1 for stator, 2 for stator yoke, 3 for stator slot, 4 for stator tooth, 5 for lower bottom of stator slot, 6 for upper bottom of stator slot, 7 for depth of stator slot, 8 for air gap, 9 for permanent magnet, 10 for rotor, 11 for rotor yoke, 12 for rotating shaft, 13 for stator optimized tooth, and 14 for stator equivalent tooth. DETAILED DESCRIPTION

[0029] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] Figure 1 The figure below is a flow chart of the optimal air gap permeability design method of the present invention. The method is described in detail below. First, the stator teeth 4 are evenly divided and the height of each stator tooth section is defined. Second, the stator slot bottom 5, stator slot top 6, and stator slot depth 7 are defined. Finally, the functional relationship between torque T and the stator teeth 4, stator slot bottom 5, stator slot top 6, and stator slot depth 7 is defined. The maximum value of torque T is solved, and the parameters of the motor stator teeth 4, stator slot bottom 5, stator slot top 6, and stator slot depth 7 for the maximum torque T are output to determine the optimal air gap permeability structure.

[0031] Figure 2 The overall structure of a permanent magnet vernier motor designed using the optimal air gap permeability design method in this patented invention includes a stator yoke 2, stator slots 3, stator teeth 4, surface-mounted permanent magnets 9, a rotor yoke 11, and a rotating shaft 12. The motor's air gap is located between the stator 1 and the rotor 10.

[0032] A permanent magnet vernier motor is designed using the above-mentioned method for determining the optimal air gap magnetic permeability structure. The permanent magnet vernier motor includes a stator and a rotor. The stator 1 includes a stator yoke 2, stator slots 3 and stator teeth 4. The rotor 10 includes permanent magnets 9, a rotor yoke 11 and a rotating shaft 12. The rotor 10 and the stator 1 are sequentially sleeved on the outer side of the rotating shaft 12. The outer surface of the permanent magnet 9 is attached to the outer side of the rotor yoke 11. An air gap 8 is provided between the stator and the rotor. The stator is provided with stator slots in the circumferential direction. Stator teeth are formed between adjacent stator slots. The permanent magnets 9 are magnetized radially, and all permanent magnets are magnetized in the same manner.

[0033] Figure 3 (a) Figure 3 Figure (b) shows the structures of the stator tooth 4, stator slot 3, stator slot bottom 5, stator slot top 6, and stator slot depth 7 before and after optimization. The stator tooth 4 is evenly divided and the particle swarm algorithm is used to find the optimal combination of hm, so, so1, and hs parameters, using the height of each tooth point hi, the width of the stator slot bottom 5 so, the width of the stator slot top 6 so1, and the stator slot depth 7hs as inputs. The optimization is performed with maximum torque as the optimization goal.

[0034] Figure 4 The stator 1 structure after optimization for the designed permanent magnet vernier motor is shown. The above stator optimization method is for optimizing one tooth slot, and the other tooth slots are obtained from the optimized tooth slot array. All tooth slots are arranged in a circular array.

[0035] Figure 5 The permanent magnet 9 structure of the designed permanent magnet vernier motor adopts radial magnetization, and all permanent magnets are magnetized in the same way.

[0036] Figure 6 The designed permanent magnet vernier motor rotor 10 structure includes a motor permanent magnet 9, a rotor yoke 11, and a rotating shaft 12. The permanent magnet 9 is attached to the outside of the rotor yoke 11, and the rotor 10 and the stator 1 are sequentially sleeved on the outside of the motor rotating shaft 12.

[0037] Figure 7a The permanent magnet vernier motor designed by the present invention has optimized teeth. Figure 7b The equivalent gear of the permanent magnet vernier motor designed by the present invention is Figure 7c The torque performance comparison chart of the optimized teeth and equivalent teeth of the permanent magnet vernier motor designed for the present invention is shown. In order to reduce the number of optimization input parameters and improve the optimization efficiency, without affecting the torque, the present invention adopts a stator equivalent tooth 14 structure, which equates the original stator optimized tooth 13 to a combination of a triangular structure and a trapezoidal structure, where θ1 and θ2 are the polar angles of the bottom endpoints of the equivalent trapezoid, and θ3 is the polar angle of the vertex of the equivalent triangle. This equivalent method can reduce the number of tooth optimization parameters m to 6. When m is large, the stator equivalent tooth 14 can greatly improve the optimization efficiency. Finally, a comparison of the torque performance of motors using two tooth structures is given. It can be seen from the figure that the torque performance of the stator equivalent tooth 14 structure is basically the same as that of the stator optimized tooth 13 structure.

[0038] Stator teeth 4 of stator 1 are designed using the optimal air-gap permeance design method. This breaks the constraints of the simple tooth structure of traditional motors by dividing the stator teeth into four equal parts, creating more degrees of freedom (m) for the stator teeth and allowing adjustment of the tooth heights (h1, h2, …, hm) of each part. The stator teeth have an optimal degree of freedom of m, and the stator teeth are divided into m+1 equal parts. Increasing m improves the permeance structure's ability to modulate the air-gap magnetic field. Reducing the optimal degree of freedom m for the stator teeth 4 improves the optimization efficiency of the optimal air-gap permeance method without compromising torque T.

[0039] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a technician familiar with this technical field within the technical scope disclosed by the present invention should be covered by the scope of protection of the present invention.

Claims

1. A method for designing the optimal air gap permeance of a permanent magnet vernier motor, characterized in that: The following steps are involved: Divide the stator tooth root of the motor evenly and define the first i The height of the split point is hi , m is the degree of freedom of the stator teeth, m ≥ i ≥1; The said i Height of the split point hi is the distance from the stator tooth root to the stator slot; The width of the bottom of the stator slot is defined as so , the width of the upper bottom of the stator slot is so1 , the depth of the stator slot is hs ; by so 、 so1 、 hs ,as well as h1 、 h2 、…、 hm As input, a seeking algorithm is used to take the motor torque T The maximum value is output, and optimization is performed to find the best hi 、 so 、 so1 and hs , thereby determining the optimal air gap magnetic permeability structure; The stator tooth root is divided into m +1 copy; The structure of the stator teeth is a combination of a triangle and a trapezoid, wherein the triangle is located above the trapezoid.

2. The method for designing the optimal air gap permeance of a permanent magnet vernier motor according to claim 1, characterized in that: Without affecting T Under the premise of reducing the degree of freedom of the motor stator teeth m It can improve the air gap magnetic field modulation capability of the magnetic permeability structure.

3. The method for designing the optimal air gap permeance of a permanent magnet vernier motor according to claim 1, characterized in that: The search algorithm is particle swarm optimization algorithm.

4. A permanent magnet vernier motor, comprising a stator and a rotor, wherein the stator comprises a stator yoke, stator slots and stator teeth, and the rotor comprises a permanent magnet, a rotor yoke and a rotating shaft, characterized in that: A permanent magnet vernier motor is designed using the method described in any one of claims 1 to 3, wherein a rotor and a stator are sequentially sleeved on the outside of a rotating shaft, the outer surface of the permanent magnet is attached to the outer side of a rotor yoke, an air gap is provided between the stator and the rotor, the stator is provided with stator slots along the circumferential direction, and stator teeth are formed between adjacent stator slots, the permanent magnets are radially magnetized, and all permanent magnets are magnetized in the same manner.

5. A permanent magnet vernier motor according to claim 4, characterized in that: Both the stator and the rotor are made of ferromagnetic materials.

6. A permanent magnet vernier motor, characterized in that: The motor is designed using the method described in any one of claims 1 to 3, wherein the teeth and slots of the motor are arranged in a circular array.

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