Stress design method and system for v-shaped built-in high-speed permanent magnet rotor magnetic isolation bridge

Abstract

The application discloses a V-shaped built-in high-speed permanent magnet rotor magnetic isolation bridge equal stress design method and system, the method comprises the following steps: S100: obtaining centrifugal force acting on the magnetic isolation bridge, establishing stress balance equation, deformation coordination condition and material physical equation of the magnetic isolation bridge, and jointly solving the load borne by the magnetic isolation bridge; S200: calculating the maximum stress borne by the magnetic isolation bridge according to the load bearing form of the magnetic isolation bridge, and obtaining constraint relationship satisfied by size parameters of the magnetic isolation bridge under the condition that the maximum stresses of the central magnetic isolation bridge and the two side magnetic isolation bridges are equal; S300: adjusting the size parameters of the central magnetic isolation bridge so as to make the stress close to the maximum allowable stress according to the constraint relationship satisfied by the size parameters of the magnetic isolation bridge, and selecting a size parameter combination with the smallest possible thickness and the largest possible width of the central magnetic isolation bridge under the premise of meeting the strength requirement and not affecting the service life of a punching die, so that the equal stress design of the high-speed V-shaped built-in permanent magnet rotor magnetic isolation bridge is realized.

Description

Technical Field

[0001] This invention belongs to the field of permanent magnet synchronous motor technology, and more specifically, relates to a stress design method and system for a V-shaped built-in high-speed permanent magnet rotor with magnetic isolation bridge. Background Technology

[0002] Built-in high-speed permanent magnet motors have attracted widespread attention in electric drive systems for new energy vehicles due to their advantages such as high power density, high efficiency, and wide power rating range. However, under high-speed operation, the enormous centrifugal force acting on the small magnetic isolation bridge of the permanent magnet rotor can easily cause structural damage to the bridge. Increasing the thickness of the magnetic isolation bridge can improve its mechanical strength, but it will lead to increased rotor leakage flux and reduced electromagnetic performance of the motor. Therefore, the size of the magnetic isolation bridge should be as small as possible while meeting mechanical strength requirements. Thus, the dimensional design of the built-in permanent magnet rotor magnetic isolation bridge is crucial to the electromagnetic performance and mechanical strength of the motor.

[0003] However, the rotor structure design of a V-type built-in high-speed permanent magnet motor is a technical challenge that urgently needs to be addressed, requiring a comprehensive consideration of the balance between the motor's electromagnetic and mechanical characteristics. A typical V-type built-in high-speed permanent magnet motor rotor structure includes a central magnetic isolation bridge (referred to as the central magnetic isolation bridge) and two side magnetic isolation bridges (referred to as the side bridges). When the rotor operates at high speed, the centrifugal force generated by the permanent magnets and pole shoes acts entirely on the magnetic isolation bridges. Since the size of the magnetic isolation bridges is usually small, the maximum stress in the rotor structure occurs at the magnetic isolation bridge location. For example, patent document CN 111783246 A discloses a method for calculating the maximum stress of a V-type built-in permanent magnet synchronous motor. By analyzing the stress state of the magnetic isolation bridge and calculating the magnitude of the force on the magnetic isolation bridge, the average stress on the magnetic isolation bridge is calculated. The maximum stress on the magnetic isolation bridge is then calculated by multiplying the average stress by the stress concentration factor. This method can be written as a MATLAB script, and during motor design, only the relevant parameters of the motor are needed to quickly calculate the maximum stress on the rotor.

[0004] However, the three magnetic isolation bridge dimensions (thickness and width) of the existing V-type permanent magnet rotor structure are mainly selected based on experience or by calculation using finite element software, which has the following shortcomings: (1) It is impossible to reduce the thickness of the magnetic isolation bridge as much as possible while meeting the structural strength requirements of the permanent magnet rotor, thereby enhancing the magnetic isolation effect of the magnetic isolation bridge and improving the electromagnetic performance of the motor. (2) The maximum stress of the central magnetic isolation bridge and the two side bridges are generally not equal, and there may even be a large difference in their maximum stress values, making it difficult to achieve full utilization of the rotor core material. Summary of the Invention

[0005] To address the aforementioned deficiencies or improvement needs of existing technologies, this invention provides a V-shaped built-in high-speed permanent magnet rotor magnetic isolation bridge equal stress design method and system. The method involves dividing the pole shoe region between the central magnetic isolation bridge and the two side magnetic isolation bridges, obtaining the centrifugal force acting on the magnetic isolation bridge and the permanent magnet, establishing the force balance equation of the magnetic isolation bridge, determining the deformation compatibility conditions and material physics equations, and jointly solving for the load on the magnetic isolation bridge. Based on the loading form of the magnetic isolation bridge, the maximum stress it experiences is calculated. Under the condition that the maximum stress of the central and side magnetic isolation bridges is equal, the constraint relationship satisfied by the dimensional parameters of the magnetic isolation bridge is obtained, thereby realizing the equal stress design of the high-speed V-shaped built-in permanent magnet rotor magnetic isolation bridge.

[0006] To achieve the above objectives, according to one aspect of the present invention, a method for designing an equal-stress V-shaped built-in high-speed permanent magnet rotor magnetic isolation bridge is provided, comprising the following steps:

[0007] S100: Obtain the centrifugal force acting on the magnetic isolation bridge, establish the force balance equation, deformation compatibility condition and material physics equation of the magnetic isolation bridge, and jointly solve the load on the magnetic isolation bridge.

[0008] S200: Calculate the maximum stress on the magnetic bridge according to the loading mode, and obtain the constraint relationship that the dimensional parameters of the magnetic bridge satisfy under the condition that the maximum stress of the central magnetic bridge and the two side magnetic bridges are equal.

[0009] S300: Based on the constraint relationship satisfied by the dimensional parameters of the magnetic isolation bridge, perform equal stress calculation on the V-shaped built-in high-speed permanent magnet rotor magnetic isolation bridge, adjust the dimensional parameters of the central magnetic isolation bridge to make its stress close to the maximum allowable stress, and select a combination of dimensional parameters with the smallest possible thickness and the largest possible width of the central magnetic isolation bridge under the premise of meeting the strength requirements and not affecting the service life of the stamping die, thereby realizing the equal stress design of the high-speed permanent magnet rotor magnetic isolation bridge.

[0010] Further, step S100 includes:

[0011] S101: Divide the pole shoe region between the central magnetic isolation bridge and the two side magnetic isolation bridges, and obtain the centrifugal force acting on the magnetic isolation bridge and the permanent magnet.

[0012] S102: Establish the force balance equation of the magnetic isolation bridge, determine the deformation compatibility conditions and material physics equations, and jointly solve the load on the magnetic isolation bridge.

[0013] Further, step S101 includes: dividing the structure into three regions symmetrical about the rotor circumference: annular G1, bow-shaped G2, and trapezoidal G3, based on the characteristics of the V-shaped built-in high-speed permanent magnet rotor magnetic isolation bridge structure.

[0014] First permanent magnet H1, second permanent magnet H2;

[0015] Based on the geometric characteristics of the region, the equivalent centroid y of the rotor structure is obtained. G :

[0016]

[0017] Where k = 1, 2, 3, A k These represent the areas of the corresponding regions.

[0018] Further, step S100 includes: obtaining the equivalent centroid y of the permanent magnet based on the geometric characteristics of the region. H :

[0019]

[0020] Where: R i α is the radius within the annular region; α is the central angle corresponding to the rotor pole shoe region; hm is the thickness of the permanent magnet; θ is the V-angle formed by the width direction of the two permanent magnets; bm is the width of the permanent magnet; c is the length from one end of the permanent magnet to the end of its slot.

[0021] Further, step S100 includes: determining the centrifugal force acting on the permanent magnet based on the obtained equivalent centrifugal center of the rotor structure and the equivalent centrifugal center of the permanent magnet.

[0022]

[0023] In the formula, ρ G and ρ H The densities of the pole shoes and permanent magnets are respectively, L a ω is the axial length of the rotor, and ω is the angular velocity of the rotor.

[0024] Further, step S100 includes: establishing the force balance equation between the central magnetic isolation bridge and the two side magnetic isolation bridges, that is, the force F on the central bridge. a and the forces F on both sides of the bridge b The sum of these forces balances the centrifugal force acting on the permanent magnet.

[0025]

[0026] Further, step S100 includes: obtaining the deformations of the central magnetic isolation bridge and the two side magnetic isolation bridges based on the forces acting on the central magnetic isolation bridge and the forces acting on the two side magnetic isolation bridges, and establishing the deformation ω of the central magnetic isolation bridge. a and the deformation of the bridge on both sides ω b Geometric compatibility conditions must be met:

[0027]

[0028] Further, step S100 includes: obtaining the analytical relationship between the forces on the central magnetic bridge and the forces on the two side magnetic bridges and the structural dimensional parameters based on the force balance equation and geometric compatibility conditions between the central magnetic bridge and the two side magnetic bridges.

[0029]

[0030] Where a2 is the thickness of the magnetic isolation bridges on both sides, b2 is the width of the magnetic isolation bridges on both sides, and b1 is the width of the central magnetic isolation bridge.

[0031] Further, step S200 includes:

[0032] S401: Calculate the maximum allowable stress of the material based on the ultimate strength and safety factor of the rotor lamination material, obtain the maximum operating speed of the permanent magnet rotor and the initial size parameters of the rotor magnetic bridge from the motor electromagnetic design scheme;

[0033] S402: Calculate the stress of the central magnetic isolation bridge and the bridges on both sides based on the initial design parameters;

[0034] S403: Adjust the size parameters of the central magnetic bridge to make its stress close to the maximum allowable stress, and select a combination of size parameters with the smallest possible thickness and the largest possible width of the central magnetic bridge, while meeting the strength requirements and not affecting the service life of the stamping die.

[0035] S404: Select appropriate width values ​​for both sides of the bridge and calculate the corresponding thickness values ​​for both sides of the bridge.

[0036] S405: Calculate the maximum deformation of the magnetic bridge and ensure that its value does not exceed 10% of the air gap length.

[0037] According to another aspect of the present invention, a V-shaped built-in high-speed permanent magnet rotor magnetic isolation bridge equal stress design system is provided, comprising:

[0038] The magnetic bridge load calculation module is used to obtain the centrifugal force acting on the magnetic bridge, establish the force balance equation, deformation compatibility condition and material physics equation of the magnetic bridge, and jointly solve the load on the magnetic bridge.

[0039] The constraint relationship solving module is used to calculate the maximum stress on the magnetic bridge based on its loading form, and to obtain the constraint relationship satisfied by the dimensional parameters of the magnetic bridge under the condition that the maximum stress of the central magnetic bridge and the two side magnetic bridges is equal.

[0040] The magnetic bridge structure design module is used to perform equal stress calculations on the V-shaped built-in high-speed permanent magnet rotor magnetic bridge based on the constraint relationship satisfied by the dimensional parameters of the magnetic bridge. It adjusts the dimensional parameters of the central magnetic bridge so that its stress is close to the maximum allowable stress. Under the premise of meeting the strength requirements and not affecting the service life of the stamping die, it selects the combination of dimensional parameters with the smallest possible thickness and the largest possible width of the central magnetic bridge, thereby realizing the equal stress design of the high-speed V-shaped built-in permanent magnet rotor magnetic bridge.

[0041] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects:

[0042] 1. The method of the present invention divides the pole shoe region between the central magnetic isolation bridge and the two side magnetic isolation bridges, obtains the centrifugal force acting on the magnetic isolation bridge and the permanent magnet, establishes the force balance equation of the magnetic isolation bridge, determines the deformation compatibility conditions and material physics equations, and jointly solves the load on the magnetic isolation bridge; calculates the maximum stress on the magnetic isolation bridge according to the loading form of the magnetic isolation bridge, and obtains the constraint relationship satisfied by the dimensional parameters of the magnetic isolation bridge under the condition that the maximum stress of the central magnetic isolation bridge and the two side magnetic isolation bridges are equal.

[0043] 2. In the method of this invention, the thickness of the two side bridges in the equal stress design scheme is reduced from 1.5mm to 1.1mm, a reduction of 26.67%, and the thickness of the central magnetic isolation bridge is reduced from 2.84mm to 2.12mm, a reduction of 25.35%. While meeting the rotor strength requirements, the significant reduction in the size of the magnetic isolation bridge can effectively reduce the rotor's leakage flux coefficient and improve the electromagnetic performance of the motor.

[0044] 3. The method of the present invention greatly simplifies the calculation of the structural strength of the rotor magnetic bridge and the design of the corresponding geometric parameters by dividing the pole shoe region between the central magnetic bridge and the two side magnetic bridges and establishing a stress-strain relationship model between the central magnetic bridge and the two side magnetic bridges. Furthermore, the method of the present invention has a high degree of consistency with the equal stress method and the finite element simulation analysis method, which verifies the effectiveness and reliability of the present invention.

[0045] 4. The method of this invention finds that under the stress design constraint of the magnetic isolation bridge, the thickness of the two side bridges is directly proportional to the square of the width of the two side bridges, and inversely proportional to the cosine of the width of the central magnetic isolation bridge and the half angle of the pole shoe. Therefore, under the condition that the mechanical strength of the central magnetic isolation bridge should be satisfied first, the dimensional parameters of the central magnetic isolation bridge should be adjusted so that its stress is close to the maximum allowable stress. Under the premise of meeting the strength requirements and not affecting the service life of the stamping die, the combination of dimensional parameters of the central magnetic isolation bridge with the smallest possible thickness and the largest possible width should be selected to effectively improve the magnetic isolation effect.

[0046] 5. The system of the present invention divides the pole shoe region between the central magnetic isolation bridge and the two side magnetic isolation bridges using a centrifugal force calculation module, and obtains the centrifugal force acting on the magnetic isolation bridge and the permanent magnet; establishes the force balance equation of the magnetic isolation bridge based on the load calculation module, determines the deformation compatibility conditions and material physics equations, and jointly solves the load on the magnetic isolation bridge; calculates the maximum stress on the magnetic isolation bridge according to the loading form of the magnetic isolation bridge using a parameter constraint module, obtains the constraint relationship satisfied by the dimensional parameters of the magnetic isolation bridge under the condition that the maximum stress of the central magnetic isolation bridge and the two side magnetic isolation bridges are equal, selects appropriate width values ​​of the two side bridges, and calculates the corresponding thickness values ​​of the two side bridges; calculates the maximum deformation of the magnetic isolation bridge, and realizes the equal stress design of the magnetic isolation bridge of the high-speed V-shaped built-in permanent magnet rotor. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the stress design method for the V-shaped built-in high-speed permanent magnet rotor magnetic isolation bridge according to an embodiment of the present invention;

[0048] Figure 2 This is the stress design process for the V-shaped built-in permanent magnet rotor magnetic isolation bridge in an embodiment of the present invention;

[0049] Figure 3 This is a schematic diagram of the V-shaped built-in permanent magnet rotor structure according to an embodiment of the present invention;

[0050] Figure 4 This is a definition and partition diagram of the V-type built-in rotor structure in an embodiment of the present invention;

[0051] Figure 5 This is a schematic diagram of the force analysis of the permanent magnet and pole shoe region in an embodiment of the present invention;

[0052] Figure 6 This is an example of the variation trend of magnetic bridge stress with the thickness of the central magnetic bridge in an embodiment of the present invention. Figure 6 Designed for unequal stress in magnetic bridges. Figure 6 Stress design of magnetic bridge, etc.

[0053] Figure 7 This is a stress distribution cloud diagram of a permanent magnet rotor calculated by the finite element method under the constant stress design of an embodiment of the present invention;

[0054] Figure 8 This is a schematic diagram of the V-shaped built-in high-speed permanent magnet rotor magnetic isolation bridge equal stress design system according to an embodiment of the present invention;

[0055] Figure 9 This is a schematic diagram of the electronic terminal structure according to an embodiment of the present invention. Detailed Implementation

[0056] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0057] like Figure 5 As shown, when the rotor rotates at high speed, the enormous centrifugal force generated by the permanent magnets and pole shoes is mainly borne by the side bridges and the central magnetic isolation bridge. For ease of analysis, only the high-speed centrifugal force is considered in the design process, ignoring the effects of other factors on the rotor; the force analysis of the rotor during steady-state operation is performed, neglecting the influence of instantaneous disturbance forces; it is assumed that the deformation of the central magnetic isolation bridge is tensile deformation, and the deformation of the side magnetic isolation bridges is bending deformation. First, the centrifugal force acting on the magnetic isolation bridge is calculated based on the equivalent center of mass principle, and the force balance equation, deformation compatibility condition, and material physics equation of the magnetic isolation bridge are written, and the load on the magnetic isolation bridge is solved jointly; then, the maximum stress on the magnetic isolation bridge is calculated according to the loading form of the magnetic isolation bridge, and under the premise that the maximum stress of the central magnetic isolation bridge and the side bridges are equal, the constraint relationship that the dimensional parameters of the magnetic isolation bridge should satisfy is derived; finally, the specific steps of the equal stress design of the magnetic isolation bridge of the V-shaped built-in high-speed permanent magnet rotor are given, thereby realizing the equal stress design of the magnetic isolation bridge of the high-speed V-shaped built-in permanent magnet rotor.

[0058] Example 1:

[0059] like Figure 4 As shown, for ease of analysis, only high-speed centrifugal force is considered in the design process, ignoring the effects of other factors on the rotor; the force analysis of the rotor during steady-state operation is performed, neglecting the influence of instantaneous disturbance forces; it is assumed that the deformation of the central magnetic bridge is tensile deformation, and the deformation of the magnetic bridges on both sides is bending deformation. Figure 1 As shown in the embodiment of the present invention, a method for designing a V-shaped built-in high-speed permanent magnet rotor with an equal stress isolation bridge is provided, which includes:

[0060] Step 1: Divide the pole shoe region between the central magnetic isolation bridge and the two side magnetic isolation bridges, and obtain the centrifugal force acting on the magnetic isolation bridges and the permanent magnet. For example... Figure 2 and Figure 3 As shown, the V-shaped built-in rotor structure consists of pole shoes and permanent magnets. The area between the symmetrical permanent magnets forms a central magnetic isolation bridge, while the sides of the permanent magnets form two magnetic isolation bridges. Specifically, the pole shoe region is divided as follows: Figure 3The diagram shows three regions: annular (G1), arc-shaped (G2), and trapezoidal (G3). The diagram also includes a first permanent magnet (H1) and a second permanent magnet (H2). The central magnetic isolation bridge has a thickness of a1 and a width of b1; the two side magnetic isolation bridges have a thickness of a2 and a width of b2; the permanent magnet has a width of bm and a thickness of hm; the distance from one end of the permanent magnet to the end of its slot is c; the slot width is lc; the central angle corresponding to the rotor pole shoe region is α; the V-angle θ formed by the width directions of the two permanent magnets is θ; the rotor outer radius is R0; and the radius within the annular region is R. i For a planar figure composed of N regions, the formula for calculating its centroid is:

[0061]

[0062] Where: k = 1, 2, ..., N, A k These are the areas of the corresponding regions:

[0063] Because the rotor structure is symmetrical about the y-axis, its equivalent centroid lies on the y-axis, that is:

[0064]

[0065]

[0066]

[0067] Similarly, the equivalent center of mass of a permanent magnet can be expressed as:

[0068]

[0069] Based on the obtained equivalent centroid of the rotor structure and the equivalent centroid of the permanent magnet, the centrifugal force generated by the permanent magnet and the pole shoe region is determined as follows:

[0070]

[0071] In the formula, ρ G and ρ H The densities of the pole shoes and permanent magnets are respectively, L a ω is the axial length of the rotor, and ω is the angular velocity of the rotor.

[0072] Step 2: Establish the force balance equation of the magnetic isolation bridge, determine the deformation compatibility conditions and material physics equations, and jointly solve the load on the magnetic isolation bridge.

[0073] according to Figure 5 The force balance relationship in the middle bridge, the force F a and the forces F on both sides of the bridge b satisfy:

[0074]

[0075] The deformations of the central and side magnetic bridges are obtained based on the forces acting on the central and side magnetic bridges. The deformation ω of the central magnetic bridge is calculated. a and the deformation of the bridge on both sides ω b Geometric compatibility conditions must be met:

[0076]

[0077] Based on the force balance equations and geometric compatibility conditions between the central magnetic isolation bridge and the two side magnetic isolation bridges, the analytical relationship between the forces on the central magnetic isolation bridge and the forces on the two side magnetic isolation bridges and the structural dimensional parameters is obtained:

[0078]

[0079] In the formula, A a and I b Let be the cross-sectional area of ​​the central magnetic isolation bridge and the moments of inertia of the two side bridges, respectively, and E be the elastic modulus of the magnetic isolation bridge material. Solving equations (7) to (9) simultaneously yields:

[0080]

[0081] Step 3: Calculate the maximum stress on the magnetic bridge based on its loading condition. Under the condition that the maximum stresses of the central and side magnetic bridges are equal, obtain the constraint relationships satisfied by the dimensional parameters of the magnetic bridge. Based on the forces on the central and side magnetic bridges, solve for the stress σ of the central magnetic bridge. a and the stress σ on both sides of the bridge b They are respectively:

[0082]

[0083] Based on the assumptions, σ a σ is the average tensile stress of the central magnetic bridge. b Let σ be the maximum bending stress on both sides of the bridge. Assume the stress σ of the central magnetic barrier bridge is... a and the stress σ on both sides of the bridge b Equal, that is:

[0084]

[0085] Based on the condition of equal stress, that is, the stress of the central magnetic bridge is equal to the stress of the magnetic bridges on both sides, the constraint relationship satisfied by the size parameters of the magnetic bridge can be obtained analytically. Substituting equation (10) into equation (12) yields:

[0086]

[0087] It is evident that, under the constraint of equal stress design for the magnetic bridge, the thickness of the two side bridges is directly proportional to the square of their widths and inversely proportional to the cosine of the width of the central magnetic bridge and the half-angle of the pole shoe. The thickness of the two side bridges is independent of the thickness of the central magnetic bridge, providing more options for selecting the magnetic bridge dimensions in equal stress design. Furthermore, it is necessary to ensure that the ratio of the maximum deformation of the magnetic bridge to the nominal air gap length of the motor is no greater than 10%, i.e.:

[0088]

[0089] In the formula, ω max =max{ω a ω b}

[0090] Step 4: Based on the constraint relationship satisfied by the dimensional parameters of the magnetic isolation bridge obtained in Step 3, perform equal stress calculation on the V-shaped built-in high-speed permanent magnet rotor magnetic isolation bridge, adjust the dimensional parameters of the central magnetic isolation bridge to make its stress close to the maximum allowable stress, and select the combination of dimensional parameters with the smallest possible thickness and the largest possible width of the central magnetic isolation bridge while meeting the strength requirements and not affecting the service life of the stamping die, so as to realize the equal stress design of the high-speed V-shaped built-in permanent magnet rotor magnetic isolation bridge.

[0091] Specifically, such as Figure 2 As shown in the embodiment of the present invention, an equal stress design method for a high-speed permanent magnet rotor magnetic isolation bridge includes the following steps:

[0092] (1) Calculate the maximum allowable stress of the material based on the ultimate strength and safety factor of the rotor lamination material, obtain the maximum operating speed of the permanent magnet rotor and the initial size parameters of the rotor magnetic bridge from the motor electromagnetic design scheme;

[0093] (2) Calculate the stress of the central magnetic isolation bridge and the bridges on both sides according to the initial design parameters and formula (11);

[0094] (3) As the main bearing structure for the centrifugal force generated by the rotor pole shoes and permanent magnets, the mechanical strength of the central magnetic isolation bridge should be given priority. The size parameters of the central magnetic isolation bridge should be adjusted to make its stress close to the maximum allowable stress. Under the premise of meeting the strength requirements and not affecting the service life of the stamping die, the size parameter combination of the central magnetic isolation bridge with the smallest possible thickness and the largest possible width should be selected to effectively improve the magnetic isolation effect.

[0095] (4) Select appropriate width values ​​for both sides of the bridge and calculate the corresponding thickness values ​​for both sides of the bridge according to formula (13);

[0096] (5) Calculate the maximum deformation of the magnetic bridge and ensure that its value does not exceed 10% of the air gap length.

[0097] The method of this invention divides the pole shoe region between the central magnetic isolation bridge and the two side magnetic isolation bridges, obtains the centrifugal force acting on the magnetic isolation bridge and the permanent magnet, establishes the force balance equation of the magnetic isolation bridge, determines the deformation compatibility conditions and material physics equations, and jointly solves the load on the magnetic isolation bridge; calculates the maximum stress on the magnetic isolation bridge according to the loading form of the magnetic isolation bridge, and obtains the constraint relationship satisfied by the dimensional parameters of the magnetic isolation bridge under the condition that the maximum stress of the central magnetic isolation bridge and the two side magnetic isolation bridges are equal.

[0098] Example 2:

[0099] In one embodiment of the present invention, the design of a V-shaped high-speed permanent magnet rotor structure with a peak speed of 25000 r / min is described. When the width of the two side bridges b2 = 3 mm, the thickness of the two side bridges a2 = 1.5 mm, and the width of the central magnetic isolation bridge b1 = 6 mm, the stress variation curves of the central magnetic isolation bridge and the two side bridges with the thickness of the central magnetic isolation bridge are as follows: Figure 6 As shown; using the equal stress design method for the magnetic isolation bridge proposed in this invention, with other parameters remaining constant, the curve of the change in magnetic isolation bridge stress with the thickness of the central magnetic isolation bridge is as follows. Figure 6 As shown, the bridge thickness a2 calculated using the equal stress design method is 1.1 mm. When the ultimate strength of the rotor core is 500 MPa, to ensure the integrity of the rotor structure, [the following is required:] Figure 6 It can be seen that the thickness of the central magnetic isolation bridge is at least a1 = 2.84 mm; however, by adopting the equal stress design method for the magnetic isolation bridge, the thickness of the central magnetic isolation bridge can be reduced to a1 = 2.12 mm. Compared with the first scheme, the thickness of the two side bridges in the equal stress design scheme is reduced from 1.5 mm to 1.1 mm, a reduction of 26.67%, and the thickness of the central magnetic isolation bridge is reduced from 2.84 mm to 2.12 mm, a reduction of 25.35%. Under the premise of meeting the rotor strength requirements, the significant reduction in the size of the magnetic isolation bridge can effectively reduce the rotor's leakage flux coefficient and improve the electromagnetic performance of the motor.

[0100] Example 3:

[0101] To verify the effectiveness of the equal stress design method, with other parameters remaining constant, when the thickness of the central magnetic isolation bridge a1 = 2.12 mm and the thickness of the two side bridges a2 = 1.1 mm, the stress distribution cloud diagram of the permanent magnet rotor calculated using finite element software is shown below. Figure 7 As shown, at an operating speed of 25000 r / min, without considering stress concentration effects, the average stress of the central magnetic bridge is approximately 516 MPa, and the maximum stress of the two side bridges is approximately 508 MPa. The errors compared to the 500 MPa predicted by the equal stress design method are 3.2% and 1.6%, respectively, indicating that the equal stress design method is effective. The design method of this invention, while considering the structural strength of the high-speed permanent magnet motor, makes maximum use of the rotor core material to minimize the size of the magnetic bridge and improve the electromagnetic performance of the motor.

[0102] Example 4:

[0103] The V-shaped built-in high-speed permanent magnet rotor magnetic isolation bridge equal stress design system provided in the embodiments of this application will be described below. The V-shaped built-in high-speed permanent magnet rotor magnetic isolation bridge equal stress design system described below can be referred to in correspondence with the V-shaped built-in high-speed permanent magnet rotor magnetic isolation bridge equal stress design method described above.

[0104] Please refer to Figure 8 , Figure 8 This is a schematic diagram of a V-shaped built-in high-speed permanent magnet rotor magnetic isolation bridge equal stress design system provided in an embodiment of this application. In this embodiment, the system includes:

[0105] The centrifugal force calculation module is used to divide the pole shoe region between the central magnetic isolation bridge and the two side magnetic isolation bridges, and to obtain the centrifugal force acting on the magnetic isolation bridge and the permanent magnet.

[0106] The load calculation module is used to establish the force balance equation of the magnetic isolation bridge, determine the deformation compatibility conditions and material physics equations, and jointly solve the load on the magnetic isolation bridge.

[0107] The parameter constraint module is used to calculate the maximum stress on the magnetic bridge based on its loading mode, and to obtain the constraint relationship that the dimensional parameters of the magnetic bridge satisfy under the condition that the maximum stress of the central magnetic bridge and the two side magnetic bridges are equal.

[0108] This application also provides a server, please refer to... Figure 9 , Figure 9 This application provides a schematic diagram of the structure of a terminal, which may include:

[0109] Memory, used to store computer programs;

[0110] The processor, when executing computer programs, can implement the steps of stress design methods such as any of the above-mentioned V-shaped built-in high-speed permanent magnet rotor magnetic isolation bridge.

[0111] like Figure 9 The diagram shows the structural composition of a terminal. The terminal device may include: a processor 10, a memory 11, a communication interface 12, and a communication bus 13. The processor 10, memory 11, and communication interface 12 all communicate with each other through the communication bus 13.

[0112] In this embodiment, the processor 10 may be a central processing unit (CPU), an application-specific integrated circuit, a digital signal processor, a field-programmable gate array, or other programmable logic devices.

[0113] The processor 10 can call the program stored in the memory 11. Specifically, the processor 10 can execute the operations in the embodiment of the abnormal IP identification method.

[0114] The memory 11 is used to store one or more programs. The programs may include program code, which includes computer operation instructions. In this embodiment, the memory 11 stores at least a program for implementing the following functions:

[0115] The centrifugal force calculation module is used to divide the pole shoe region between the central magnetic isolation bridge and the two side magnetic isolation bridges, and obtain the centrifugal force acting on the magnetic isolation bridge and the permanent magnet.

[0116] The force balance equation of the magnetic isolation bridge is established based on the load calculation module, the deformation compatibility conditions and material physics equations are determined, and the load on the magnetic isolation bridge is solved jointly.

[0117] The parameter constraint module calculates the maximum stress on the magnetic bridge based on its loading form, and obtains the constraint relationship that the dimensional parameters of the magnetic bridge satisfy under the condition that the maximum stress of the central magnetic bridge and the two side magnetic bridges are equal.

[0118] In one possible implementation, the memory 11 may include a program storage area and a data storage area, wherein the program storage area may store the operating system and applications required for at least one function; and the data storage area may store data created during use.

[0119] In addition, memory 11 may include high-speed random access memory, and may also include non-volatile memory, such as at least one disk storage device or other volatile solid-state storage device.

[0120] Communication interface 12 can be an interface for the communication module, used to connect with other devices or systems.

[0121] Of course, it should be noted that the structure shown does not constitute a limitation on the server in the embodiments of this application. In actual applications, the server may include more or fewer components than shown, or combine certain components.

[0122] This application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, can implement the steps of any of the above-described farmland planting and irrigation management methods.

[0123] The computer-readable storage medium may include various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0124] For a description of the computer-readable storage medium provided in this application, please refer to the above method embodiments; further details will not be repeated here.

[0125] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0126] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0127] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0128] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for designing a V-shaped built-in high-speed permanent magnet rotor with an equal stress isolation bridge, characterized in that, Includes the following steps: S100: Obtain the centrifugal force acting on the magnetic isolation bridge, establish the force balance equation, deformation compatibility condition and material physics equation of the magnetic isolation bridge, and jointly solve the load on the magnetic isolation bridge. S200: Calculate the maximum stress on the magnetic bridge according to the loading mode, and obtain the constraint relationship that the dimensional parameters of the magnetic bridge satisfy under the condition that the maximum stress of the central magnetic bridge and the two side magnetic bridges are equal. S300: Based on the constraint relationship satisfied by the dimensional parameters of the magnetic isolation bridge, perform equal stress calculation on the V-shaped built-in high-speed permanent magnet rotor magnetic isolation bridge, adjust the dimensional parameters of the central magnetic isolation bridge to make its stress close to the maximum allowable stress, and select the dimensional parameter combination of the central magnetic isolation bridge with the smallest possible thickness and the largest possible width, under the premise of meeting the strength requirements and not affecting the service life of the stamping die, so as to realize the equal stress design of the high-speed V-shaped built-in permanent magnet rotor magnetic isolation bridge; Step S200 includes: S401: Calculate the maximum allowable stress of the material based on the ultimate strength and safety factor of the rotor lamination material, obtain the maximum operating speed of the permanent magnet rotor and the initial size parameters of the rotor magnetic bridge from the motor electromagnetic design scheme; S402: Calculate the stress of the central magnetic isolation bridge and the bridges on both sides based on the initial design parameters; S403: Adjust the size parameters of the central magnetic bridge to make its stress close to the maximum allowable stress, and select a combination of size parameters with the smallest possible thickness and the largest possible width of the central magnetic bridge, while meeting the strength requirements and not affecting the service life of the stamping die. S404: Select appropriate width values ​​for both sides of the bridge and calculate the corresponding thickness values ​​for both sides of the bridge. S405: Calculate the maximum deformation of the magnetic bridge and ensure that its value does not exceed 10% of the air gap length.

2. The stress design method for a V-shaped built-in high-speed permanent magnet rotor magnetic isolation bridge according to claim 1, characterized in that, Step S100 includes: S101: Divide the pole shoe region between the central magnetic isolation bridge and the two side magnetic isolation bridges, and obtain the centrifugal force acting on the magnetic isolation bridge and the permanent magnet. S102: Establish the force balance equation of the magnetic isolation bridge, determine the deformation compatibility conditions and material physics equations, and jointly solve the load on the magnetic isolation bridge.

3. The V-shaped built-in high-speed permanent magnet rotor magnetic isolation bridge equal stress design method according to claim 2, characterized in that, Step S101 includes: based on the structural characteristics of the V-shaped built-in high-speed permanent magnet rotor magnetic bridge, dividing it into annular sections symmetrical about the rotor circumference. bow shape and trapezoid Three areas; First permanent magnet Second permanent magnet ; Based on the geometric characteristics of the region, the equivalent centroid of the rotor structure is obtained: ， Where k = 1, 2, 3, These represent the areas of the corresponding regions.

4. The V-shaped built-in high-speed permanent magnet rotor magnetic isolation bridge equal stress design method according to claim 3, characterized in that, Step S100 includes: obtaining the equivalent centroid of the permanent magnet based on the geometric characteristics of the region. ， in: The radius of the annular region; This is the central angle corresponding to the rotor pole shoe region; The thickness of the permanent magnet; The V-angle formed by the width of the two permanent magnets; The width of the permanent magnet; It is the length from one end of the permanent magnet to the end of its slot.

5. The V-shaped built-in high-speed permanent magnet rotor magnetic isolation bridge equal stress design method according to claim 4, characterized in that, Step S100 includes: determining the centrifugal force acting on the permanent magnet based on the obtained equivalent centrifugal center of the rotor structure and the equivalent centrifugal center of the permanent magnet. ， In the formula, and These are the densities of the pole shoes and the permanent magnets, respectively. The axial length of the rotor. ω is the rotor angular velocity.

6. A method for designing an equal-stress V-shaped built-in high-speed permanent magnet rotor magnetic isolation bridge according to any one of claims 1-5, characterized in that, Step S100 includes: establishing the force balance equation between the central magnetic isolation bridge and the two side magnetic isolation bridges, that is, the force on the central bridge. and the stress on both sides of the bridge The sum of these forces balances the centrifugal force acting on the permanent magnet. 。 7. The V-shaped built-in high-speed permanent magnet rotor magnetic isolation bridge equal stress design method according to claim 6, characterized in that, Step S100 includes: obtaining the deformations of the central magnetic isolation bridge and the two side magnetic isolation bridges based on the forces acting on the central magnetic isolation bridge and the forces acting on the two side magnetic isolation bridges, and establishing the deformation of the central magnetic isolation bridge. and deformation of the bridge on both sides Geometric compatibility conditions must be met: 。 8. The V-shaped built-in high-speed permanent magnet rotor magnetic isolation bridge equal stress design method according to claim 7, characterized in that, Step S100 includes: obtaining the analytical relationship between the forces on the central magnetic bridge and the forces on the two side magnetic bridges and the structural dimensional parameters based on the force balance equations and geometric compatibility conditions between the central magnetic bridge and the two side magnetic bridges. ， in, The thickness of the magnetic bridges on both sides. The width of the magnetic bridges on both sides; This represents the width of the central magnetic bridge.

9. A V-shaped built-in high-speed permanent magnet rotor magnetic isolation bridge equal stress design system, characterized in that, include: The magnetic bridge load calculation module is used to obtain the centrifugal force acting on the magnetic bridge, establish the force balance equation, deformation compatibility condition and material physics equation of the magnetic bridge, and jointly solve the load on the magnetic bridge. The constraint relationship solving module is used to calculate the maximum stress on the magnetic bridge according to the loading form of the magnetic bridge, and to obtain the constraint relationship satisfied by the dimensional parameters of the magnetic bridge under the condition that the maximum stress of the central magnetic bridge and the two side magnetic bridges is equal. The magnetic bridge structure design module is used to perform equal stress calculations on the V-shaped built-in high-speed permanent magnet rotor magnetic bridge based on the constraint relationship satisfied by the dimensional parameters of the magnetic bridge. It adjusts the dimensional parameters of the central magnetic bridge to make its stress close to the maximum allowable stress. Under the premise of meeting the strength requirements and not affecting the service life of the stamping die, it selects the combination of dimensional parameters with the smallest possible thickness and the largest possible width of the central magnetic bridge, thereby realizing the equal stress design of the high-speed V-shaped built-in permanent magnet rotor magnetic bridge. The following steps are performed in the constraint relationship solving module: S401: Calculate the maximum allowable stress of the material based on the ultimate strength and safety factor of the rotor lamination material, obtain the maximum operating speed of the permanent magnet rotor and the initial size parameters of the rotor magnetic bridge from the motor electromagnetic design scheme; S402: Calculate the stress of the central magnetic isolation bridge and the bridges on both sides based on the initial design parameters; S403: Adjust the size parameters of the central magnetic bridge to make its stress close to the maximum allowable stress, and select a combination of size parameters with the smallest possible thickness and the largest possible width of the central magnetic bridge, while meeting the strength requirements and not affecting the service life of the stamping die. S404: Select appropriate width values ​​for both sides of the bridge and calculate the corresponding thickness values ​​for both sides of the bridge. S405: Calculate the maximum deformation of the magnetic bridge and ensure that its value does not exceed 10% of the air gap length.

Images