Built-in permanent magnet synchronous motor no-load magnetic field acquisition method, system and device and medium
By dividing the built-in permanent magnet synchronous motor structure into subdomains and using the separation variable method to calculate vector magnetic positions, the problem of difficult to quickly and accurately calculate the no-load magnetic field in the existing technology is solved, and efficient magnetic field calculation and motor optimization design are achieved .
Patent Information
- Application Number
- CN202411482708.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-23
- Publication Date
- 2025-02-18
AI Technical Summary
The prior art is difficult to quickly and accurately calculate the no-load magnetic field of the built-in permanent magnet synchronous motor. Especially in the case of complex structures, the finite element method takes a long time to calculate and is difficult to combine with intelligent analysis methods, and the analytical method is difficult to calculate in complex structures.
By dividing the built-in motor structure into subdomains, including stator slots, air gaps, magnetic isolation bridges and rotor slots, the general solution expression of vector magnetic positions in each subdomain is obtained by separating variables, and the boundary conditions of adjacent subdomains are established, and the calculation is carried out. The vector magnetic bits in each subdomain are finally calculated.
It realizes the fast and accurate calculation of the no-load magnetic field of a built-in permanent magnet synchronous motor, shortens the calculation time, greatly improves efficiency compared with finite element simulation, and can be combined with optimization algorithms, suitable for the rapid optimization design of motors.
Smart Images
Figure CN119475690A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a method, system, device and medium for acquiring a no-load magnetic field of a built-in permanent magnet synchronous motor, and belongs to the technical field of magnetic field analysis of permanent magnet synchronous motors. Background Art
[0002] Permanent magnet synchronous motors have the advantages of high performance, high power density, and high controllability. They are widely used in many fields such as industrial production, rail transportation, and electric vehicles. Permanent magnet synchronous motors with high performance, low torsional vibration, and low noise are becoming more and more popular. At present, the research on permanent magnet synchronous motors mainly focuses on motor structure optimization, electromagnetic vibration analysis, shaft voltage suppression, and multi-physics field simulation. The basis for the above research is to establish an effective motor magnetic field calculation method to achieve fast and accurate calculation of the motor magnetic field.
[0003] At present, analytical methods and finite element methods are often used to calculate the magnetic field of the motor. The finite element method has high calculation accuracy and can take into account the influence of many factors such as complex motor structure, core saturation, and permanent magnet demagnetization. However, this method requires dense segmentation of the motor simulation model, which is time-consuming and difficult to combine with advanced intelligent analysis methods, limiting the scope of application of this method. Existing analytical methods mainly include magnetomotive force-permeability method, conformal transformation method, subdomain method, etc. The analytical method has a fast calculation speed and can perform in-depth analysis of the motor mechanism. With the emergence of various optimized analytical methods, the calculation accuracy of the analytical method has been greatly improved, and the scope of application has become wider. However, the structure of the built-in permanent magnet synchronous motor is relatively complex, and there are many difficulties in using analytical methods to calculate the magnetic field of this type of motor. Summary of the invention
[0004] The purpose of the present invention is to provide a method, system, device and medium for obtaining the no-load magnetic field of a built-in permanent magnet synchronous motor. This technology is suitable for the rapid and accurate calculation of the no-load magnetic field of a V-type built-in permanent magnet synchronous motor, and provides technical support for subsequent research on motor multi-physical field simulation, motor structure optimization, electromagnetic vibration reduction, etc.
[0005] In order to achieve the above object, the present invention is implemented through the following technical solutions: A method for acquiring no-load magnetic field of a built-in permanent magnet synchronous motor comprises the following steps: Divide the internal motor structure into subdomains, including stator slots, stator slot openings, air gaps, magnetic isolation bridges, and rotor slots; Combining the structural parameters of each subdomain, the general expression of the vector magnetic potential in each subdomain is obtained by using the separation of variables method. Establishing boundary conditions of adjacent subdomains, and calculating the vector magnetic potential in each subdomain according to the boundary conditions; Based on the vector magnetic potential in each subdomain, the no-load magnetic field of the motor is calculated.
[0006] Preferably, the general solution expression of the vector magnetic potential in the rotor slot subdomain is as follows: , in, , Indicates The vector magnetic potential in the rotor slot subdomain is and are the radial and tangential positions, respectively, is the vacuum permeability, and Respectively i The radial and tangential components of the magnetization intensity of the permanent magnet in each rotor slot are taken as the values corresponding to the center position of the rotor slot subdomain. , , , is the coefficient to be determined, Indicates The radius of the rotor slot bottom, Indicates The radius of the rotor slot top, Indicates The rotor slot width angle, Indicates The rotor slot center position angle.
[0007] Preferably, the vector magnetic potential in the two magnetic isolation bridges between the rotor slot and the outer surface of the rotor and The general solution expressions are: , , in, , is the width angle of the magnetic isolation bridge, , , , , , , , are all undetermined coefficients, and are the top radius and bottom radius of the magnetic isolation bridge, respectively. express The corresponding magnetic isolation bridge center position angle; The vector magnetic potential in the magnetic bridge between the rotor slots The general solution expression is as follows: , in, , is the width angle of the magnetic isolation bridge, , , is the coefficient to be determined, and They are respectively the top radius and bottom radius of the above-mentioned magnetic isolation bridge.
[0008] Preferably, the vector magnetic potential in each subdomain is calculated according to the boundary conditions, specifically in the following manner: Establish boundary conditions for all subdomains; The general solution expression of the vector magnetic potential in each subdomain is solved together with the boundary conditions to obtain the relationship satisfied by the unknown coefficients of the general solution expression of the vector magnetic potential. The matrix equation form of the relationship is as follows: , in, is the coefficient matrix derived based on the boundary conditions, is the constant matrix derived based on the boundary conditions; The specific values of the unknown coefficients are obtained according to the relationship, and are substituted into the general expression of the vector magnetic potential in the corresponding subdomain to obtain the final expression of the vector magnetic potential in each subdomain.
[0009] Preferably, the rotor slot boundary conditions are as follows: , , , in, For the The tangential component of the magnetic field strength in the rotor slot sub-domain, .
[0010] A no-load magnetic field acquisition system for a built-in permanent magnet synchronous motor, comprising: The subdomain division module is configured to: divide the interior permanent magnet synchronous motor structure into subdomains and determine the structural parameters of each subdomain; The boundary condition calculation module is configured to: derive boundary conditions between adjacent subdomains according to structural parameters of each subdomain; The magnetic potential calculation module is configured to: derive a general solution expression of the vector magnetic potential in each subdomain, and on this basis calculate the vector magnetic potential of the subdomain in combination with boundary conditions; The magnetic field calculation module is configured to calculate the no-load magnetic field of the motor based on the vector magnetic potential in each sub-domain.
[0011] A device for acquiring a no-load magnetic field of a built-in permanent magnet synchronous motor comprises a processor and a memory storing program instructions. The processor is configured to execute a method for acquiring a no-load magnetic field of a built-in permanent magnet synchronous motor when running the program instructions.
[0012] A computer-readable storage medium stores a computer program, which implements the method when executed by a processor.
[0013] The advantages of the present invention are as follows: the present invention provides a method for calculating the no-load magnetic field of a built-in permanent magnet synchronous motor, by which the no-load magnetic field of the motor can be quickly and accurately calculated, greatly shortening the calculation time compared with finite element simulation; at the same time, the method can be combined with advanced optimization algorithms to make it suitable for the rapid optimization design of the motor. The present invention facilitates the calculation of the motor magnetic field and electromagnetic parameters, and provides an effective means for the electromagnetic design of the permanent magnet synchronous motor. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.
[0015] Figure 1 Schematic diagram of the method flow chart.
[0016] Figure 2 It is a schematic diagram of each sub-domain of the motor; Figure 3 Schematic diagram of rotor subdomain division. DETAILED DESCRIPTION
[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0018] Example 1 like Figure 1 As shown, a method for obtaining a no-load magnetic field of a built-in permanent magnet synchronous motor comprises the following steps: S1: Divide the built-in motor structure into subdomains, including stator slots, stator slot openings, air gaps, magnetic isolation bridges, and rotor slots.
[0019] S2: Combining the structural parameters of each subdomain, the separation of variables method is used to obtain the general solution expression of the vector magnetic potential in each subdomain.
[0020] S3: Establish boundary conditions of adjacent subdomains, and calculate the vector magnetic potential in each subdomain based on the boundary conditions.
[0021] S4: Calculate the no-load magnetic field of the motor based on the vector magnetic potential in each subdomain.
[0022] As a refinement of the above embodiment, step S1 reasonably divides the motor structure into several sub-domains and transforms them into radial sector or circular ring structures.
[0023] According to the periodicity of the motor magnetic field, a motor model under one pole is taken for analysis. Figure 2 The sub-domains include stator slots, stator slot openings, air gaps, magnetic isolation bridges and rotor slots. According to the stator structure of the motor, the stator slots and stator slot openings are directly simplified into radial sector structures; the air gap is a circular ring structure.
[0024] The magnetic permeability of permanent magnets is approximately the same as that of air, and the air region in the rotor slot can be regarded as a permanent magnet with zero magnetic field strength. Figure 3 As shown, the permanent magnet and air regions in the rotor slots are divided into H The top radius of the previous sector is the same as the bottom radius of the next sector, and the midpoint of each sector side is located on the hypotenuse of the rotor slot. The structure of each sector is determined by 4 parameters, including the bottom radius , Top Radius , center position angle and width angle Based on the principle of subdomain division and combined with the rotor slot structural parameters, the values of the above four parameters can be determined.
[0025] Combined with the motor rotor saturation area, the magnetic isolation bridge is equivalent to three radial sector structures, two of which are located between the rotor slot and the rotor outer surface, and one is located between two rotor slots. So far, the sub-domain division of the motor magnetic field solution area has been completed.
[0026] As a refinement of the above embodiment, the general solution expression of the vector magnetic potential in the rotor slot (permanent magnet) subdomain in step S2 is as follows: , in, , Indicates The vector magnetic potential in the rotor slot subdomain is and are the radial and tangential positions, respectively, is the vacuum permeability, and Respectively i The radial and tangential components of the magnetization intensity of the permanent magnet in each rotor slot are taken as the values corresponding to the center position of the rotor slot subdomain. , , , is the coefficient to be determined, Indicates The radius of the rotor slot bottom, Indicates The radius of the rotor slot top, Indicates The rotor slot width angle, Indicates The rotor slot center position angle.
[0027] Specifically, the general solution expression process of the vector magnetic potential in the rotor slot subdomain is as follows: The permanent magnet is linearly demagnetized and the influence of eddy current is ignored. i The vector magnetic potential of the rotor slot sub-domain A zi Satisfies the following equation: , The separation of variables method is used to solve the general expression of the vector magnetic potential in the permanent magnet subdomain.
[0028] As a refinement of the above embodiment, the magnetic isolation bridge includes two magnetic isolation bridges located between the rotor slots and the outer surface of the rotor and a magnetic isolation bridge located between the rotor slots.
[0029] The vector magnetic potential in the two magnetic isolation bridges between the rotor slot and the outer surface of the rotor and The general solution expressions are: , , in, , is the width angle of the magnetic isolation bridge, , , , , , , , are all undetermined coefficients, and are the top radius and bottom radius of the magnetic isolation bridge, respectively. express The corresponding center position angle of the magnetic isolation bridge.
[0030] The vector magnetic potential in the magnetic bridge between the rotor slots The general solution expression is as follows: , in, , is the width angle of the magnetic isolation bridge, , , is the coefficient to be determined, and They are respectively the top radius and bottom radius of the above-mentioned magnetic isolation bridge.
[0031] Specifically, the general solution expression process of the two magnetic isolation bridges between the rotor slots and the outer surface of the rotor and the vector magnetic potential in the magnetic isolation bridge between the rotor slots is as follows: The vector magnetic potential in the magnetic isolation bridge subdomain satisfies the following equation: , The separation of variables method is used to solve the general expression of the vector magnetic potential in the two magnetic isolation bridges between the rotor slots and the rotor outer surface.
[0032] The vector magnetic potential in the air gap, stator slot, and stator slot subdomains satisfies the following equations: , In the formula, , is the motor speed. Similarly, the general expression of the vector magnetic potential in each of the above subdomains can be obtained by using the separation of variables method, which has been given in existing literature and will not be introduced here.
[0033] As a refinement of the above embodiment, the step S3 calculates the vector magnetic potential in each subdomain according to the boundary conditions, and the specific method is as follows: Establish boundary conditions for all subdomains; The general solution expression of the vector magnetic potential in each subdomain is solved together with the boundary conditions to obtain the relationship satisfied by the unknown coefficients of the general solution expression of the vector magnetic potential. The matrix equation form of the relationship is as follows: , in, is the coefficient matrix derived based on the boundary conditions, is the constant matrix derived based on the boundary conditions; The specific values of the unknown coefficients are obtained according to the relationship, and are substituted into the general expression of the vector magnetic potential in the corresponding subdomain to obtain the final expression of the vector magnetic potential in each subdomain.
[0034] As a refinement of the above embodiment, the rotor slot boundary conditions are as follows: At the interface between the two subdomains, the tangential component of the magnetic field intensity is continuous, based on which the following boundary condition can be obtained: (1) in, For the The tangential component of the magnetic field strength in a permanent magnet subdomain.
[0035] In addition, the vector magnetic potential is continuous at the interface between the two subdomains, from which we can obtain: (2) The above formula is only It is valid within the interval and cannot constitute a complete boundary condition. Therefore, the supplementary boundary condition is derived in combination with the equivalent transformation.
[0036] Referring to the first boundary condition, it can be deduced that: , From the above formula, we can get: Here, ,and .
[0037] On this basis, combining the above formula with the general solution expression of the vector magnetic potential in the rotor slot subdomain, it can be derived that: (3) in, , Indicates The radius of the rotor slot top, Indicates The vector magnetic potential in the rotor slot subdomain is , , , Indicates The coefficients of the rotor slot subdomains are unknown. Indicates The tangential component of the magnetization intensity of a rotor slot sub-domain.
[0038] Equations (1), (2), and (3) together constitute another complete boundary condition. So far, two complete boundary conditions between adjacent permanent magnet subdomains have been derived. The boundary conditions between the remaining subdomains can be derived on this basis or have been given in existing studies, so they will not be elaborated in detail here.
[0039] Example 2 A no-load magnetic field acquisition system for a built-in permanent magnet synchronous motor, comprising: The subdomain division module is configured to: divide the interior permanent magnet synchronous motor structure into subdomains and determine the structural parameters of each subdomain; The boundary condition calculation module is configured to: derive boundary conditions between adjacent subdomains according to structural parameters of each subdomain; The magnetic potential calculation module is configured to: derive a general solution expression of the vector magnetic potential in each subdomain, and on this basis calculate the vector magnetic potential of the subdomain in combination with boundary conditions; The magnetic field calculation module is configured to calculate the no-load magnetic field of the motor based on the vector magnetic potential in each sub-domain.
[0040] Example 3 The embodiment of the present disclosure also provides a device for acquiring a no-load magnetic field of a built-in permanent magnet synchronous motor, including a processor and a memory. Optionally, the device may also include a communication interface and a bus. The processor, the communication interface, and the memory may communicate with each other through the bus. The communication interface may be used for information transmission. The processor may call the logic instructions in the memory to execute the no-load magnetic field acquisition method of the built-in permanent magnet synchronous motor of the above embodiment.
[0041] In addition, the logic instructions in the above-mentioned memory can be implemented in the form of software functional units and can be stored in a computer-readable storage medium when sold or used as an independent product.
[0042] The memory, as a computer-readable storage medium, can be used to store software programs and computer executable programs, such as program instructions / modules corresponding to the method in the embodiment of the present disclosure. The processor executes the function application and data processing by running the program instructions / modules stored in the memory, that is, the no-load magnetic field acquisition method of the built-in permanent magnet synchronous motor in the above embodiment is realized.
[0043] The memory may include a program storage area and a data storage area, wherein the program storage area may store an operating system and an application required for at least one function; the data storage area may store data created according to the use of the terminal device, etc. In addition, the memory may include a high-speed random access memory and may also include a non-volatile memory.
[0044] An embodiment of the present disclosure provides a computer-readable storage medium storing computer-executable instructions, wherein the computer-executable instructions are configured to execute the above-mentioned method for acquiring the no-load magnetic field of the built-in permanent magnet synchronous motor.
[0045] The computer-readable storage medium mentioned above may be a transient computer-readable storage medium or a non-transitory computer-readable storage medium.
[0046] The technical solution of the embodiment of the present disclosure can be embodied in the form of a software product, which is stored in a storage medium and includes one or more instructions for enabling a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in the embodiment of the present disclosure. The aforementioned storage medium may be a non-transient storage medium, including: a USB flash drive, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a disk or an optical disk, and other media that can store program codes, or a transient storage medium.
[0047] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. A method for obtaining no-load magnetic field of a built-in permanent magnet synchronous motor, characterized in that: The steps include: Divide the internal motor structure into subdomains, including stator slots, stator slot openings, air gaps, magnetic isolation bridges, and rotor slots; Combining the structural parameters of each subdomain, the general expression of the vector magnetic potential in each subdomain is obtained by using the separation of variables method. Establishing boundary conditions of adjacent subdomains, and calculating the vector magnetic potential in each subdomain according to the boundary conditions; Based on the vector magnetic potential in each subdomain, the no-load magnetic field of the motor is calculated.
2. The method for obtaining no-load magnetic field of an interior permanent magnet synchronous motor according to claim 1, characterized in that: The general expression of the vector magnetic potential in the rotor slot subdomain is as follows: ， in, , Indicates The vector magnetic potential in the rotor slot subdomain is and are the radial and tangential positions, respectively, is the vacuum permeability, and Respectively i The radial and tangential components of the magnetization intensity of the permanent magnet in each rotor slot are taken as the values corresponding to the center position of the rotor slot subdomain. , , , is the coefficient to be determined, Indicates The radius of the rotor slot bottom, Indicates The radius of the rotor slot top, Indicates The rotor slot width angle, Indicates The rotor slot center position angle.
3. The method for obtaining no-load magnetic field of a built-in permanent magnet synchronous motor according to claim 1, characterized in that: The vector magnetic potential in the two magnetic isolation bridges between the rotor slots and the outer surface of the rotor and The general solution expressions are: ， ， in, , is the width angle of the magnetic isolation bridge, , , , , , , , are all undetermined coefficients, and are the top radius and bottom radius of the magnetic isolation bridge, respectively. express The corresponding magnetic isolation bridge center position angle; The vector magnetic potential in the magnetic bridge between the rotor slots The general solution expression is as follows: ， in, , is the width angle of the magnetic isolation bridge, , , is the coefficient to be determined, and They are respectively the top radius and bottom radius of the above-mentioned magnetic isolation bridge.
4. The method for acquiring no-load magnetic field of an interior permanent magnet synchronous motor according to claim 1, characterized in that: The vector magnetic potential in each subdomain is calculated based on the boundary conditions. The specific method is as follows: Establish boundary conditions for all subdomains; The general solution expression of the vector magnetic potential in each subdomain is solved together with the boundary conditions to obtain the relationship satisfied by the unknown coefficients of the general solution expression of the vector magnetic potential. The matrix equation form of the relationship is as follows: ， in, is the coefficient matrix derived based on the boundary conditions, is the constant matrix derived based on the boundary conditions; The specific values of the unknown coefficients are obtained according to the relationship, and are substituted into the general expression of the vector magnetic potential in the corresponding subdomain to obtain the final expression of the vector magnetic potential in each subdomain.
5. The method for acquiring no-load magnetic field of an interior permanent magnet synchronous motor according to claim 4, characterized in that: The rotor slot boundary conditions are as follows: ， ， ， in, For the The tangential component of the magnetic field strength in the rotor slot sub-domain, .
6. A no-load magnetic field acquisition system for a built-in permanent magnet synchronous motor for executing the method described in any one of claims 1 to 5, characterized in that: include: The subdomain division module is configured to: divide the interior permanent magnet synchronous motor structure into subdomains and determine the structural parameters of each subdomain; The boundary condition calculation module is configured to: derive boundary conditions between adjacent subdomains according to structural parameters of each subdomain; The magnetic potential calculation module is configured to: derive a general solution expression of the vector magnetic potential in each subdomain, and on this basis calculate the vector magnetic potential of the subdomain in combination with boundary conditions; The magnetic field calculation module is configured to calculate the no-load magnetic field of the motor based on the vector magnetic potential in each sub-domain.
7. A device for acquiring no-load magnetic field of a built-in permanent magnet synchronous motor, comprising a processor and a memory storing program instructions, characterized in that: The processor is configured to execute the no-load magnetic field acquisition method of the built-in permanent magnet synchronous motor as described in any one of claims 1-5 when running the program instructions.
8. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the program is executed by a processor, the method described in any one of claims 1 to 5 is implemented.