Switched reluctance motor rotor structure for improving torque performance and optimization method thereof

Abstract

The invention discloses a switched reluctance motor rotor structure for improving torque performance and an optimization method thereof, and belongs to the technical field of switched reluctance motors. The rotor structure comprises a rotor iron core formed by pressing amorphous alloy steel sheets and is provided with a plurality of rotor teeth, the outer sides of the rotor teeth are provided with unique tooth structures obtained through topological optimization, and the center of the rotor iron core is provided with a circular hole for installing a rotating shaft; through a topological optimization method, the outer side structure of the rotor teeth is optimized by taking the maximum average torque as a target and taking the vibration displacement and the elastic strain energy of the stator and rotor cores as constraint conditions without increasing the torque pulsation at the same time; according to the structure, the output torque and the operation efficiency of the motor are remarkably improved, torque pulsation and vibration are effectively suppressed, the mechanical strength of the rotor core is ensured, and the torque performance of the motor is comprehensively improved; according to the optimization method, the heat dissipation performance is also considered, air flow is promoted by reasonably designing a tooth part structure, the running temperature of the motor is reduced, and the service life is prolonged; the unique rotor design enhances the electromagnetic compatibility and reduces the electromagnetic interference.

Description

Technical Field

[0001] The present invention relates to the technical field of switched reluctance motors, and in particular to a switched reluctance motor rotor structure for improving torque performance and an optimization method thereof. Background Art

[0002] Energy, as the core of modern society, is an important driving force for global industrialization and urbanization. However, while the traditional fossil energy system has brought economic prosperity, it has also caused serious environmental problems, such as water and soil pollution, intensified global climate change, and damage to the ecosystem. Therefore, developing new energy electric vehicles and reducing dependence on oil and automobile exhaust emissions have become a global consensus and important response measures.

[0003] Switched reluctance motor (SRM) has shown great application potential in the field of new energy electric vehicles due to its low cost, simple and solid structure, high efficiency and energy saving, wide speed regulation range, high reliability and durability. However, despite the many advantages of switched reluctance motor, its low operating efficiency and extremely high torque pulsation and vibration noise limit its further promotion and application.

[0004] In order to improve the torque performance of the switched reluctance motor, increase motor efficiency and reduce torque pulsation, current research mainly focuses on the motor's structural design, drive and control strategies. These studies are committed to improving the output torque and reducing torque pulsation by optimizing the motor structure, improving the drive method or control algorithm. However, the torque pulsation mechanism of the switched reluctance motor is complex, and the torque performance is affected by many factors, so some existing optimization schemes have not fully achieved the expected results.

[0005] For example, CN101667758A discloses a switched reluctance motor rotor structure, which is a switched reluctance motor rotor structure made of stacked silicon steel sheets, has no windings and no permanent magnets, and the rotor pole type is a multi-air-gap salient pole structure for reducing vibration and noise, and the rotor end salient pole is a multi-air-gap step type; this structure improves the torque pulsation and vibration noise of the motor to a certain extent, but its effect on improving the output torque of the motor is limited.

[0006] For another example, CN102347675A discloses a switched reluctance motor rotor structure, in which axially through-connecting holes are provided on both sides of the rotor teeth, a connecting conductor is embedded in the connecting hole, two ends of the connecting conductor are respectively connected to copper rings at two ends of the motor, and a damping winding is formed through the copper rings to generate a reverse magnetic field to weaken the degree of inductance change on the main magnetic flux, thereby reducing torque pulsation, harmonic loss, and electromagnetic noise. However, the axially through-connecting holes provided in this scheme will reduce the mechanical strength of the motor rotor core, and the processing operation is complicated, which is not conducive to large-scale production and application.

[0007] In summary, although the existing technology has improved the torque performance and vibration noise of the switched reluctance motor to a certain extent, it often has problems such as limited improvement effect, affecting other motor performance or complex processing. Therefore, how to effectively suppress the torque pulsation of the switched reluctance motor and the vibration displacement of the stator and rotor core while improving the motor output torque and maintaining the mechanical strength of the rotor core has become a technical problem that needs to be solved urgently.

[0008] It is in this context that the present invention proposes a new switched reluctance motor rotor structure and an optimization method for improving torque performance, aiming to achieve an all-round improvement in the motor torque performance by optimizing the external structure of the rotor teeth while maintaining the normal operation and mechanical strength of the motor. Summary of the invention

[0009] The technical problem to be solved by the present invention is to provide a switched reluctance motor rotor structure and an optimization method thereof for improving torque performance, so as to solve the technical problems of insufficient torque performance, large torque pulsation and high vibration noise existing in the operation of the existing switched reluctance motor.

[0010] In order to solve the above technical problems, the technical solution adopted by the present invention is: a switched reluctance motor rotor structure with improved torque performance, comprising a rotor core, wherein the rotor core is provided with a plurality of rotor teeth, each rotor tooth is provided with a unique tooth structure on the outer side, and a circular hole is opened in the center of the rotor core for installing an external rotating shaft.

[0011] In a preferred solution, the rotor core is assembled with an external stator core of a suitable size to achieve an improvement in torque performance.

[0012] In a preferred solution, the rotor core is formed by pressing amorphous alloy steel sheets.

[0013] In a preferred solution, the unique tooth structure arranged on the outer side of the rotor teeth is obtained after topological optimization.

[0014] A method for optimizing a switched reluctance motor rotor structure for improving torque performance adopts a switched reluctance motor rotor structure for improving torque performance as described in any one of the above items. The method adopts a topology optimization method, takes maximizing the average torque of the switched reluctance motor as the optimization target during topology optimization, takes not increasing the torque pulsation of the switched reluctance motor, the vibration displacement of the stator and rotor cores, and the elastic strain energy of the rotor core as the constraint conditions during topology optimization, and adopts the global convergence moving asymptote method to solve the problem based on the solid isotropic material penalty model SIMP.

[0015] In a preferred embodiment, the specific steps of the optimization method are: Step 1: Select the area to be optimized; Step 2: Establish a topology optimization mathematical model for the area selected in step 1; Step 3: Construct the objective function and constraints of topology optimization; Step 4: Use the global convergence moving asymptote method to calculate the optimal solution that meets the topology optimization objective function and constraints.

[0016] In the preferred solution, the specific steps of step 1 for selecting the area to be optimized are: Step 1.1: In the simulation model of the normally operating switched reluctance motor, the flux density changes of the motor stator and rotor cores are observed. It is found that the flux density of the rotor teeth near the stator and rotor air gap is large and the magnetic circuit is relatively concentrated. According to the operating principle of the switched reluctance motor, the optimization area is selected as the outer side of the rotor teeth, and the topology optimization method is used to obtain a unique tooth structure in this area; Step 1.2: During topology optimization, only one quarter of the switched reluctance motor rotor core is selected as the optimization area and topology optimization is performed. Then, after symmetry, the rotor core consisting of all rotor teeth with a unique tooth structure can be obtained.

[0017] In the preferred solution, the method and steps for establishing the topology optimization mathematical model of the area selected in step 1 in step 2 are as follows: based on the SIMP model, the design variables are introduced , the relative magnetic permeability of the core material in the optimized area and Young's modulus Use the design variables to represent continuous functions and set the penalty factor Penalize the intermediate density units to reduce the number of intermediate density units in the topology optimization results, thereby obtaining a shape structure that is easy to process, and then optimize the relative permeability of the regional material. and Young's modulus Respectively expressed as: (1) In the formula, The relative magnetic permeability of the amorphous alloy steel sheet pressed into the rotor core of the switched reluctance motor is is the Young's modulus of the same amorphous alloy steel sheet, is the Young’s modulus of air in the air gap region of the switched reluctance motor.

[0018] In the preferred solution, the specific steps of step 3 to construct the objective function and constraint conditions of topology optimization are: Step 3.1: To achieve the optimization goal of maximizing the average torque of the switched reluctance motor, the objective function is set to the average torque of the switched reluctance motor during operation, and the motor torque at each rotor positionT θ It is expressed as: (2) In the formula, is the radius of the air gap, is the motor shaft length, is the integrated radian, and They are respectively the magnetic induction intensity The radial and tangential components of Then, the average torque of the switched reluctance motor during operation is It can be expressed as: (3) In the formula, N is the total number of rotor positions; Step 3.2: In order to ensure that the motor torque pulsation and core vibration will not be aggravated while the average torque of the motor is increased, the constraint condition is set to that the motor torque pulsation and the stator and rotor core vibration displacement will not increase at each iteration of the topology optimization. The motor torque pulsation coefficient at each iteration of the topology optimization is It is expressed as: (4) In the formula, is the maximum torque value, is the minimum torque value, is the average torque value; The stator and rotor cores of the switched reluctance motor are considered to be made of linear elastic materials, and the damping effect of the core is ignored. During the calculation process, the electromagnetic force and magnetostrictive force that cause the motor vibration are coupled to the elastic mechanics formula, and the vibration displacement of the stator and rotor core of the motor at each iteration of the topology optimization is calculated. It is expressed as: (5) In the formula, is the mass matrix, is the stiffness matrix, is the electromagnetic force, is the magnetostrictive force, For time; In addition, in order to ensure the mechanical strength of the motor rotor core after optimization, elastic strain energy constraints are added to the constraints, limiting the elastic strain energy caused by electromagnetic force and magnetostrictive force to be less than the initial value. It is expressed as: (6) In the formula, is the total load in the mechanical field, expressed as , for The transposed matrix of Step 3.3: Based on the topology optimization objective function and constraint-related physical quantity calculation formulas in step 3.1 and step 3.2, the topology optimization objective function for improving the motor torque performance is And three constraints , , Respectively expressed as: (7) Where: For the The motor torque ripple coefficient at the optimization iteration, is the initial motor torque ripple coefficient, For the The vibration displacement of the motor stator and rotor core at the optimization iteration, is the initial motor stator and rotor core vibration displacement, For the The elastic strain energy of the motor rotor core at the iteration, is the initial elastic strain energy of the motor rotor core.

[0019] In the preferred solution, the step 4 uses the global convergence moving asymptote method to calculate the optimal solution that satisfies the topology optimization objective function and constraints. Compared with the traditional moving asymptote method, the global convergence moving asymptote method updates the design variables according to the positive and negative sensitivity values ​​and has stronger global convergence.

[0020] The invention provides a switched reluctance motor rotor structure and an optimization method thereof for improving torque performance, which have the following beneficial effects: 1. The invention proposes a switched reluctance motor rotor structure for improving torque performance, which is pressed from an amorphous alloy steel sheet. The amorphous alloy is prepared by rapid solidification technology, and has no crystal structure or structural defects that hinder the movement of magnetic domain walls. The strip is extremely thin (20 to 30 μm), which significantly reduces the eddy current and hysteresis losses of the motor core, greatly improving the working efficiency of the motor. 2. The switch reluctance motor rotor structure for improving torque performance proposed in the present invention can effectively improve the motor output torque and operating efficiency while ensuring the mechanical strength of the rotor core, and can effectively suppress the torque pulsation of the switch reluctance motor and the vibration displacement of the stator and rotor core. Therefore, the motor rotor structure proposed in the present invention can achieve an all-round improvement in the motor torque performance without affecting the normal operation of the motor; 3. The present invention proposes a method for optimizing the rotor structure of a switched reluctance motor for improving torque performance. The unique tooth structure arranged on the outer side of the rotor teeth is obtained by a topological optimization method, and finally the optimal distribution of materials with excellent performance can be achieved. As a quantitative design method, topological optimization has become a major engineering technology means for modern engineering innovation design. The optimization method proposed by the present invention is conducive to the processing and manufacturing of the rotor core structure, and is widely used in the fields of new energy electric vehicles and industrial control. 4. The optimization method of the present invention also takes heat dissipation into consideration. By rationally designing the tooth structure, air flow is promoted, the motor operating temperature is reduced, and the service life is extended. At the same time, the unique rotor design enhances electromagnetic compatibility and reduces electromagnetic interference, providing reliable protection for the application of motors in the field of precision control. 5. The present invention adopts the global convergence moving asymptote method to calculate the optimal solution that meets the topology optimization objective function and constraint conditions. Compared with the traditional moving asymptote method, this method effectively avoids the problem that the traditional method is prone to fall into the local optimum, significantly improves the optimization efficiency and accuracy, and significantly improves the torque performance of the motor rotor structure, meeting the stringent requirements of high-performance motor design; 6. The present invention designs a unique tooth structure on the outer side of the rotor teeth, which is obtained through topological optimization. Through the unique tooth structure and optimized rotor structure, the output torque and operating efficiency of the switched reluctance motor are significantly improved while ensuring the mechanical strength of the rotor core; 7. The present invention effectively suppresses the torque pulsation of the motor and the vibration displacement of the stator and rotor cores while ensuring the improvement of the torque performance, thereby improving the stability and comfort of the motor; 8. The application of the amorphous alloy material of the present invention enhances the mechanical strength of the rotor core, making the motor more reliable during operation; 9. Through simulation and experimental verification, the technical solution of the present invention has shown significant advantages in improving torque performance and reducing torque pulsation and vibration noise; 10. The technical solution of the present invention has broad application prospects in the fields of new energy electric vehicles, etc., and provides strong support for promoting technological progress and product upgrades in related fields; 11. The present invention also realizes real-time monitoring and adaptive adjustment of the motor operation status by integrating intelligent control algorithms, further improving the intelligence level and overall performance of the motor system, and injecting new vitality into the development of intelligent manufacturing and green travel. 12. The intelligent features of the present invention not only simplify the operation and maintenance process, but also significantly reduce energy consumption and promote efficient use of resources; its innovative design leads the new trend of motor technology and provides key technical support for the transformation and upgrading of related industries. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be further described below in conjunction with the accompanying drawings and implementation examples: Figure 1 Schematic diagram of the rotor structure of the switched reluctance motor of the present invention; Figure 2 Schematic diagram of the rotor structure of a traditional switched reluctance motor; Figure 3 This is a flow chart of the optimization method of the rotor structure of the switched reluctance motor of the present invention; Figure 4 Design variables for optimization areas before topology optimization ρ Distribution map of Figure 5 Design variables for the optimized region after topology optimization of the present invention ρ Distribution map of Figure 6 This is the magnetic flux density distribution diagram of the stator and rotor of the traditional switched reluctance motor at t=4ms; Figure 7 The magnetic flux density distribution diagram of the stator and rotor of the switched reluctance motor of the present invention at the time t=4ms; Figure 8 A torque performance comparison diagram of the switched reluctance motor model of the present invention and the traditional switched reluctance motor model; Fig. 9 A comparison diagram of the vibration displacement of the stator and rotor cores of the switched reluctance motor model of the present invention and the traditional switched reluctance motor model; In the figure: rotor core 1, rotor teeth 2, rotor teeth 2, outer side 3, tooth structure 4, circular hole 5, stator core 6. DETAILED DESCRIPTION

[0022] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments: Example 1 like Figure 1 and 2 As shown, a switched reluctance motor rotor structure for improving torque performance includes a rotor core 1, wherein the rotor core 1 is provided with a plurality of rotor teeth 2, and the outer side 3 of each rotor tooth 2 is provided with a unique tooth structure 4, and a circular hole 5 is opened in the center of the rotor core 1 for installing an external shaft.

[0023] In this embodiment, the rotor core 1 is assembled with an external stator core 6 of a suitable size to achieve an improvement in torque performance.

[0024] Furthermore, the rotor core 1 is formed by pressing amorphous alloy steel sheets.

[0025] Furthermore, the unique tooth structure 4 disposed on the outer side 3 of the rotor tooth 2 is obtained after topological optimization.

[0026] Example 2 In another preferred embodiment, based on the above embodiment 1, Figure 3 As shown, a method for optimizing the rotor structure of a switched reluctance motor with improved torque performance adopts a switched reluctance motor rotor structure with improved torque performance as described in any one of the above items. The method adopts a topology optimization method, takes maximizing the average torque of the switched reluctance motor as the optimization goal during topology optimization, takes not increasing the torque pulsation of the switched reluctance motor, the vibration displacement of the stator and rotor cores, and the elastic strain energy of the rotor core as the constraint conditions during topology optimization, and adopts the global convergence moving asymptote method to solve based on the Solid Isotropic Material with Penalization model (SIMP).

[0027] In this embodiment, the specific steps of the optimization method are: Step 1: Select the area to be optimized; Step 2: Establish a topology optimization mathematical model for the area selected in step 1; Step 3: Construct the objective function and constraints of topology optimization; Step 4: Use the global convergence moving asymptote method to calculate the optimal solution that meets the topology optimization objective function and constraints.

[0028] Furthermore, the specific steps of step 1 for selecting the area to be optimized are: Step 1.1: In the simulation model of the normally operating switched reluctance motor, the flux density changes of the motor stator and rotor cores are observed. It is found that the flux density of the rotor teeth near the stator and rotor air gap is large and the magnetic circuit is relatively concentrated. According to the operating principle of the switched reluctance motor, the optimization area is selected as the outer side 3 of the rotor tooth 2, and the topology optimization method is used to obtain a unique tooth structure 4 for this area; Step 1.2: During topology optimization, only one quarter of the switched reluctance motor rotor core 1 is selected as the optimization area and topology optimization is performed. Then, through symmetry, the rotor core 1 consisting of all rotor teeth 2 including the unique tooth structure 4 can be obtained.

[0029] Furthermore, the method and steps for establishing the topology optimization mathematical model of the area selected in step 1 in step 2 are as follows: based on the SIMP model, the design variables are introduced. , the relative magnetic permeability of the core material in the optimized area and Young's modulus Use the design variables to represent continuous functions and set the penalty factor Penalize the intermediate density units to reduce the number of intermediate density units in the topology optimization results, thereby obtaining a shape structure that is easy to process, and then optimize the relative permeability of the regional material. and Young's modulus Respectively expressed as: (1) In the formula, The relative magnetic permeability of the amorphous alloy steel sheet pressed into the rotor core 1 of the switched reluctance motor is is the Young's modulus of the same amorphous alloy steel sheet, is the Young’s modulus of air in the air gap region of the switched reluctance motor.

[0030] Furthermore, the specific steps of step 3 to construct the objective function and constraint conditions of topology optimization are: Step 3.1: To achieve the optimization goal of maximizing the average torque of the switched reluctance motor, the objective function is set to the average torque of the switched reluctance motor during operation, and the motor torque at each rotor position T θ It is expressed as: (2) In the formula, is the radius of the air gap, is the motor shaft length, is the integrated radian, and They are respectively the magnetic induction intensity The radial and tangential components of Then, the average torque of the switched reluctance motor during operation is It can be expressed as: (3) In the formula, N is the total number of rotor positions; Step 3.2: In order to ensure that the motor torque pulsation and core vibration will not be aggravated while the average torque of the motor is increased, the constraint condition is set to that the motor torque pulsation and the stator and rotor core vibration displacement will not increase at each iteration of the topology optimization. The motor torque pulsation coefficient at each iteration of the topology optimization is It is expressed as: (4) In the formula, is the maximum torque value, is the minimum torque value, is the average torque value; The stator and rotor cores of the switched reluctance motor are considered to be made of linear elastic materials, and the damping effect of the core is ignored. During the calculation process, the electromagnetic force and magnetostrictive force that cause the motor vibration are coupled to the elastic mechanics formula, and the vibration displacement of the stator and rotor core of the motor at each iteration of the topology optimization is calculated. It is expressed as: (5) In the formula, is the mass matrix, is the stiffness matrix, is the electromagnetic force, is the magnetostrictive force, For time; In addition, in order to ensure the mechanical strength of the motor rotor core after optimization, elastic strain energy constraints are added to the constraints, limiting the elastic strain energy caused by electromagnetic force and magnetostrictive force to be less than the initial value. It is expressed as: (6) In the formula, is the total load in the mechanical field, expressed as , for The transposed matrix of Step 3.3: Based on the topology optimization objective function and constraint-related physical quantity calculation formulas in step 3.1 and step 3.2, the topology optimization objective function for improving the motor torque performance is And three constraints , , Respectively expressed as: (7) Where: For the The motor torque ripple coefficient at the optimization iteration, is the initial motor torque ripple coefficient, For the The vibration displacement of the motor stator and rotor core at the optimization iteration, is the initial motor stator and rotor core vibration displacement, For the The elastic strain energy of the motor rotor core at the iteration, is the initial elastic strain energy of the motor rotor core.

[0031] Furthermore, the step 4 uses a global convergent moving asymptote method to calculate the optimal solution that satisfies the topology optimization objective function and constraint conditions. Compared with the traditional moving asymptote method, the global convergent moving asymptote method updates the design variables according to the positive and negative sensitivity values ​​and has stronger global convergence.

[0032] Example 3 In another preferred embodiment, the specific implementation steps of a switched reluctance motor rotor structure and an optimization method thereof for improving torque performance are as follows: Firstly, the rotor structure of the switched reluctance motor involved in the present invention is composed of a rotor core 1, which is pressed from an amorphous alloy steel sheet. Due to the characteristics of the amorphous alloy steel sheet prepared by rapid solidification technology, there is no crystal structure and structural defects that hinder the movement of magnetic domain walls, and the strip is extremely thin (about 20 to 30 μm), which significantly reduces the eddy current and hysteresis losses of the motor core, thereby improving the working efficiency of the motor.

[0033] A plurality of rotor teeth 2 are arranged on the rotor core 1, and the outer side 3 of each rotor tooth 2 obtains a unique tooth structure 4 through a topological optimization method; this unique tooth structure 4 is intended to optimize the magnetic flux path and improve the torque performance of the motor; in addition, a circular hole 5 is opened in the center of the rotor core 1 for installing an external shaft to realize the rotational motion of the motor.

[0034] During the optimization process, the specific methods and steps are as follows: Step 1: Select the optimization area In the simulation model of the normally operating switched reluctance motor, the change in magnetic flux density of the motor stator and rotor core is observed. Through simulation analysis, it is found that the magnetic flux density of the rotor teeth near the air gap between the motor stator and rotor is large, and the magnetic circuit is relatively concentrated. According to the operating principle of the switched reluctance motor, the magnetic flux density and magnetic circuit distribution on the rotor teeth have a significant impact on the motor torque performance. Therefore, the outer side 3 of the rotor tooth 2 is selected as the optimization area, and the topology optimization method is used to optimize this area to obtain a unique tooth structure 4.

[0035] In order to reduce the calculation time and considering that the rotor teeth 2 of the switched reluctance motor have the same structure, in this embodiment, only one quarter of the rotor core 1 is selected as the optimization area for topological optimization. After the optimization is completed, the complete rotor core 1 including all the unique tooth structures 4 can be obtained through symmetric processing.

[0036] Step 2: Establish a mathematical model for topology optimization Based on the Solid Isotropic Material Penalty Model (SIMP), design variables are introduced , the relative magnetic permeability of the core material in the optimized area and Young's modulus Use the design variables to represent continuous functions; at the same time, set the penalty factor Penalize the intermediate density units to reduce the number of intermediate density units in the topology optimization results, thereby obtaining a shape structure that is easy to process, and then optimize the relative permeability of the regional material. and Young's modulus It is expressed as the functional relationship shown in formula (1).

[0037] Step 3: Construct the objective function and constraints of topology optimization The objective function is set as the average torque when the switched reluctance motor is running , and its calculation formula is shown in formula (3). In order to ensure that the motor torque pulsation and core vibration will not be aggravated while improving the average torque of the motor, the constraint condition is set to the motor torque pulsation coefficient at each iteration of the topology optimization. and the vibration displacement of the stator and rotor core The torque ripple coefficient does not exceed the initial value. and vibration displacement The calculation formulas of are shown in Equation (4) and Equation (5) respectively. In addition, elastic strain energy constraints are added to ensure that the elastic strain energy caused by electromagnetic force and magnetostrictive force is Smaller than the initial value to maintain the mechanical strength of the motor rotor core.

[0038] Step 4: Find the optimal solution The global convergence moving asymptote method is used to calculate the optimal solution that meets the topology optimization objective function and constraints. Compared with the traditional moving asymptote method, this method has stronger global convergence and can more accurately find the design variables that meet the optimization objectives. distributed.

[0039] Through the above optimization steps, a switched reluctance motor rotor core 1 with a unique tooth structure 4 is finally obtained. This structure can significantly improve the torque performance of the motor while suppressing torque pulsation and vibration noise.

[0040] Example 4 On the basis of the above-mentioned embodiments 1, 2, and 3, in order to further verify the effectiveness of the present invention, the switched reluctance motor rotor structure of embodiments 1 and 3 and the optimization method described in embodiments 2 and 3 are used to simulate the optimized switched reluctance motor and the traditional switched reluctance motor respectively. The simulation basis and principle of the overall structure of the switched reluctance motor are as follows: The magnetic field area of ​​the stator and rotor core of the switched reluctance motor satisfies the differential equation: (8) In the formula, is the conductivity, is the vacuum permeability, is the current density, is the relative magnetic permeability of the material; is the vector magnetic potential, existing in the entire magnetic field area and satisfying: (9) In the formula, is the magnetic induction intensity, For Get the curl; The stator and rotor cores of the switched reluctance motor are considered to be made of linear elastic materials. Ignoring the damping effect, the vibration process can be described by the dynamic equation of the elastic body: (5) In the electromagnetic simulation software, two-dimensional models of the switched reluctance motor of the present invention and the traditional switched reluctance motor are respectively established, and simulation analysis is performed, such as Figure 1 and Figure 2 The simulation results are shown in Figure 6 and Figure 7 Compare the magnetic flux density of the stator and rotor models of the two switched reluctance motors at t=4ms, as shown in Figure 6 and Figure 7 As shown in the figure, it can be seen that the maximum magnetic flux density of the switched reluctance motor before and after optimization is 1.31T, and the magnetic flux density distribution of the switched reluctance motor before and after optimization remains almost unchanged, which shows that the rotor structure of the switched reluctance motor proposed in the present invention has almost no effect on the normal operation of the motor; then combined with Figure 8 As shown in the figure, the torque performance of the switched reluctance motor model of the present invention is compared with that of the traditional switched reluctance motor model. It can be seen that the average torque of the switched reluctance motor proposed by the present invention is increased by 11%, and the torque ripple coefficient is reduced from the original 73% to 60%. This shows that the present invention effectively suppresses the motor torque ripple while improving the motor output torque, thereby significantly improving the torque performance of the motor; finally, combined with Fig. 9 As shown, by comparing the vibration displacement of the motor stator and rotor cores of the switched reluctance motor model of the present invention with that of the traditional switched reluctance motor model, it can be seen that the vibration displacement of the motor stator and rotor cores corresponding to the switched reluctance motor rotor structure proposed in the present invention is reduced, further proving that the present invention has better vibration reduction and noise reduction effects while improving the torque performance.

[0041] In a preferred embodiment, the rotor core 1 is assembled with an external stator core 6 of suitable size to achieve improved torque performance. The above configuration improves the universality of the switched reluctance motor rotor structure with improved torque performance, which contributes to its wide application in new energy electric vehicles and industrial control fields.

[0042] In the preferred scheme, the rotor core 1 is pressed from amorphous alloy steel sheets; the above settings effectively improve the energy efficiency ratio of the motor and reduce energy loss; at the same time, the high magnetic permeability and low hysteresis loss characteristics of the amorphous alloy steel sheets enable the rotor core 1 to maintain a stable magnetic field environment even at high speeds, ensuring the smooth operation of the motor; further reducing the eddy current and hysteresis losses of the rotor core of the switched reluctance motor, and improving the operating efficiency of the switched reluctance motor.

[0043] In the preferred scheme, the unique tooth structure 4 arranged on the outer side 3 of the rotor tooth 2 is obtained after topological optimization; the above arrangement not only effectively improves the dynamic performance of the rotor and reduces vibration and noise, but also obtains the optimal structure of the switched reluctance motor rotor with improved torque performance through topological optimization, and finally achieves the optimal distribution of materials with excellent performance, thereby maximizing the torque performance of the switched reluctance motor.

[0044] In summary, the invention provides a switched reluctance motor rotor structure with improved torque performance and an optimization method thereof, which solves the technical problems of insufficient torque performance, large torque pulsation, high vibration and noise in the operation of the existing switched reluctance motor. While improving the motor output torque and maintaining the mechanical strength of the rotor core, the switched reluctance motor torque pulsation and the vibration displacement of the stator and rotor core can be effectively suppressed, and the motor torque performance can be improved in an all-round way. In addition, the switched reluctance motor rotor structure provided by the invention is conducive to processing and manufacturing, and is conducive to its wide application in the fields of new energy electric vehicles and industrial control. The invention designs a unique tooth on the outer side of the rotor teeth. The structure is obtained through topological optimization, aiming to improve the torque performance and operating efficiency of the motor. Compared with the traditional switched reluctance motor, this unique tooth structure shows significant superiority and innovation in reducing the concentration of magnetic flux density and improving the torque output; the rotor core is pressed from amorphous alloy steel sheets. Amorphous alloys have the characteristics of no crystal structure, high resistivity, low hysteresis loss, etc., which can significantly reduce the eddy current and hysteresis loss of the motor and improve the overall efficiency of the motor. The application of this material in the field of switched reluctance motor is novel; in the optimization process, not only the maximization of the average torque of the switched reluctance motor is taken as the optimization goal, but also the torque pulsation, stator and rotor iron are taken into consideration. The core vibration displacement and elastic strain energy of the rotor core are considered as constraints; this optimization strategy that comprehensively considers multiple performance indicators makes the optimization result more comprehensive and practical; when solving the topology optimization problem, the global convergence moving asymptote method is adopted. Compared with the traditional method, this method has stronger global convergence and can improve the calculation efficiency while ensuring the calculation accuracy. The innovative application of this solution method provides a more effective way to optimize the rotor structure of the switched reluctance motor; the present invention adopts a unique rotor tooth structure design, the application of amorphous alloy materials and an optimization strategy that comprehensively considers multiple performance indicators. This scheme improves the torque performance of the switched reluctance motor and reduces Significant effects have been achieved in reducing torque pulsation and vibration noise, and improving motor efficiency. This comprehensive performance improvement reflects the outstanding achievements of the solution in technological innovation. In addition, the solution also has good process feasibility and cost-effectiveness. Although the introduction of amorphous alloy materials has a slightly higher initial cost, in the long run, its high-efficiency characteristics can greatly reduce energy consumption, achieve energy conservation and emission reduction, and open up a new path for the development of green motor technology. In the future, with the continuous advancement of materials science and optimization algorithms, the solution will be further optimized, which will promote the widespread application of switched reluctance motors in new energy vehicles, industrial automation and other fields, and lead motor technology to develop in a more efficient and environmentally friendly direction.

Claims

1. A switched reluctance motor rotor structure for improving torque performance, comprising a rotor core (1), characterized in that: The rotor core (1) is provided with a plurality of rotor teeth (2), the outer side (3) of each rotor tooth (2) is provided with a unique tooth structure (4), and a circular hole (5) is provided at the center of the rotor core (1) for mounting an external rotating shaft.

2. The switched reluctance motor rotor structure for improving torque performance according to claim 1, characterized in that: The rotor core (1) is assembled and used with an external stator core (6) of suitable size to achieve improved torque performance.

3. The switched reluctance motor rotor structure for improving torque performance according to claim 2, characterized in that: The rotor core (1) is formed by pressing amorphous alloy steel sheets.

4. The switched reluctance motor rotor structure for improving torque performance according to claim 3, characterized in that: The unique tooth structure (4) arranged on the outer side (3) of the rotor tooth (2) is obtained after topological optimization.

5. A method for optimizing the rotor structure of a switched reluctance motor for improving torque performance, characterized in that: A switched reluctance motor rotor structure with improved torque performance as described in any one of claims 1 to 4 is adopted, and the method is to adopt a topology optimization method, to maximize the average torque of the switched reluctance motor as the optimization goal during topology optimization, to not increase the torque pulsation of the switched reluctance motor, the vibration displacement of the stator and rotor cores, and the elastic strain energy of the rotor core as the constraint conditions during topology optimization, and to adopt a global convergence moving asymptote method based on the solid isotropic material penalty model SIMP for solving the problem.

6. The method for optimizing the rotor structure of a switched reluctance motor for improving torque performance according to claim 5, characterized in that: The specific steps of the optimization method are: Step 1: Select the area to be optimized; Step 2: Establish a topology optimization mathematical model for the area selected in step 1; Step 3: Construct the objective function and constraints of topology optimization; Step 4: Use the global convergence moving asymptote method to calculate the optimal solution that meets the topology optimization objective function and constraints.

7. The method for optimizing the rotor structure of a switched reluctance motor for improving torque performance according to claim 6, characterized in that: The specific steps of step 1 for selecting the area to be optimized are: Step 1.1: In the simulation model of the normally operating switched reluctance motor, the flux density changes of the motor stator and rotor cores are observed. It is found that the flux density of the rotor teeth near the stator and rotor air gap is relatively large and the magnetic circuit is relatively concentrated. According to the operating principle of the switched reluctance motor, the optimization area is selected as the outer side (3) of the rotor teeth (2), and the topology optimization method is used to obtain a unique tooth structure (4) in this area. Step 1.2: During topology optimization, only one quarter of the switched reluctance motor rotor core (1) is selected as the optimization area and topology optimization is performed. Then, after symmetry, the rotor core (1) consisting of all rotor teeth (2) including the unique tooth structure (4) can be obtained.

8. The method for optimizing the rotor structure of a switched reluctance motor for improving torque performance according to claim 6, characterized in that: The method and steps for establishing the topology optimization mathematical model of the area selected in step 1 in step 2 are as follows: based on the SIMP model, the design variables are introduced. , the relative magnetic permeability of the core material in the optimized area and Young's modulus Use the design variables to represent continuous functions and set the penalty factor Penalize the intermediate density units to reduce the number of intermediate density units in the topology optimization results, thereby obtaining a shape structure that is easy to process, and then optimize the relative permeability of the regional material. and Young's modulus Respectively expressed as: （1） In the formula, The relative magnetic permeability of the amorphous alloy steel sheet pressed into the rotor core (1) of the switched reluctance motor is is the Young's modulus of the same amorphous alloy steel sheet, is the Young’s modulus of air in the air gap region of the switched reluctance motor.

9. The method for optimizing the rotor structure of a switched reluctance motor for improving torque performance according to claim 6, characterized in that: The specific steps of step 3 to construct the objective function and constraints of topology optimization are: Step 3.1: To achieve the optimization goal of maximizing the average torque of the switched reluctance motor, the objective function is set to the average torque of the switched reluctance motor during operation, and the motor torque at each rotor position T θ It is expressed as: （2） In the formula, is the radius of the air gap, is the motor shaft length, is the integrated radian, and They are respectively the magnetic induction intensity The radial and tangential components of Then, the average torque of the switched reluctance motor during operation is It can be expressed as: （3） In the formula, N is the total number of rotor positions; Step 3.2: In order to ensure that the motor torque pulsation and core vibration will not be aggravated while the average torque of the motor is increased, the constraint condition is set to that the motor torque pulsation and the stator and rotor core vibration displacement will not increase at each iteration of the topology optimization. The motor torque pulsation coefficient at each iteration of the topology optimization is It is expressed as: （4） In the formula, is the maximum torque value, is the minimum torque value, is the average torque value; The stator and rotor cores of the switched reluctance motor are considered to be made of linear elastic materials, and the damping effect of the core is ignored. During the calculation process, the electromagnetic force and magnetostrictive force that cause the motor vibration are coupled to the elastic mechanics formula, and the vibration displacement of the stator and rotor core of the motor at each iteration of the topology optimization is calculated. It is expressed as: （5） In the formula, is the mass matrix, is the stiffness matrix, is the electromagnetic force, is the magnetostrictive force, For time; In addition, in order to ensure the mechanical strength of the motor rotor core after optimization, elastic strain energy constraints are added to the constraints, limiting the elastic strain energy caused by electromagnetic force and magnetostrictive force to be less than the initial value. It is expressed as: （6） In the formula, is the total load in the mechanical field, expressed as , for The transposed matrix of Step 3.3: Based on the topology optimization objective function and constraint-related physical quantity calculation formulas in step 3.1 and step 3.2, the topology optimization objective function for improving the motor torque performance is And three constraints , , Respectively expressed as: （7） Where: For the The motor torque ripple coefficient at the optimization iteration, is the initial motor torque ripple coefficient, For the The vibration displacement of the motor stator and rotor core at the optimization iteration, is the initial motor stator and rotor core vibration displacement, For the The elastic strain energy of the motor rotor core at the iteration, is the initial elastic strain energy of the motor rotor core.

10. The method for optimizing the rotor structure of a switched reluctance motor for improving torque performance according to claim 6, characterized in that: The step 4 uses the global convergence moving asymptote method to calculate the optimal solution that meets the topology optimization objective function and constraint conditions. Compared with the traditional moving asymptote method, the global convergence moving asymptote method updates the design variables according to the positive and negative sensitivity values ​​and has stronger global convergence.

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