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CN-121984258-A - Axial flux permanent magnet synchronous reluctance motor rotor based on modularized harmonic cancellation

CN121984258ACN 121984258 ACN121984258 ACN 121984258ACN-121984258-A

Abstract

The invention discloses an axial flux permanent magnet synchronous reluctance motor rotor based on modularized harmonic cancellation, which is designed into a three-in-one structure, gradient magnetic barriers and computable dislocation phase, wherein a rotor assembly is formed by splicing N fan-shaped rotor modules along the circumference, adjacent modules are provided with optimal dislocation angles calculated by a harmonic cancellation principle, so that the sum of target harmonic magnetic field vectors generated by each module is zero, U-shaped magnetic barrier arrays with monotonically gradient change geometric parameters and embedded permanent magnet groups are arranged in the fan-shaped rotor modules, and the permanent magnet synchronous reluctance motor rotor is capable of canceling main electromagnetic harmonics from the source, decoupling magnetism gathering and resistance increasing functions, improving the mechanical robustness and electromagnetic performance of the motor, converting the whole processing into standardized module assembly, reducing the manufacturing cost and maintenance difficulty, flexibly adapting to different motor pole numbers and being suitable for high-end application scenes such as new energy automobiles, industrial driving, aerospace and the like.

Inventors

  • Request for anonymity

Assignees

  • 宁波小为智能科技有限公司

Dates

Publication Date
20260505
Application Date
20260228

Claims (10)

  1. 1. The axial flux permanent magnet synchronous reluctance motor rotor based on modularized harmonic cancellation is applied to an axial flux permanent magnet synchronous reluctance motor and is characterized by comprising a stator assembly and rotor assemblies which are opposite to the stator assembly in terms of air gap maintenance, wherein the stator assembly comprises a motor stator and an armature winding, the motor rotor assembly comprises a segmented dislocated magnetic barrier rotor, a permanent magnet group embedded in the segmented dislocated magnetic barrier rotor and a non-magnetic high-strength protection device integrated on the rotor, the segmented dislocated magnetic barrier rotor consists of N fan-shaped rotor modules spliced in the circumferential direction, N is an integer greater than or equal to 2, each fan-shaped rotor module is mechanically independent, an optimal dislocation angle theta calculated according to a harmonic cancellation principle is arranged between every two adjacent fan-shaped rotor modules, so that the sum of harmonic magnetic field vectors of the same target space generated by the N fan-shaped rotor modules is zero, M U-shaped magnetic barriers are arranged inside each fan-shaped rotor module, M is greater than or equal to 2, key geometric parameters of the U-shaped magnetic barriers are changed in a monotonic gradient along the circumferential direction, the permanent magnet group is embedded in the U-shaped magnetic barriers, the fan-shaped magnetic barriers are bonded with each fan-shaped rotor module through axial tension bars, and the sealing joint strength is realized, and the sealing joint strength between the fan-shaped rotor modules and the sealing strength is high.
  2. 2. The axial flux permanent magnet synchronous reluctance motor rotor based on modularized harmonic cancellation according to claim 1, wherein N is preferably 4 and corresponds to a 90-degree sector rotor module, M is preferably 3, and the key geometric parameters of the U-shaped magnetic barrier comprise a notch width W and a notch depth H.
  3. 3. The rotor of the modular harmonic cancellation-based axial flux permanent magnet synchronous reluctance motor according to claim 1, wherein the optimal dislocation angle θ is a mechanical angle, and the design principle is that a target harmonic phase difference of K×P generated by adjacent fan-shaped rotor modules is 360 °/N, K is a positive integer, P is the number of poles of the motor, and the vector sum after superposition of N segmented harmonic magnetic fields is 0.
  4. 4. The modularized harmonic cancellation-based axial flux permanent magnet synchronous reluctance motor rotor is characterized in that high-precision mechanical positioning features are arranged on two side end faces of the fan-shaped rotor module, the positioning features are salient pole connecting faces and concave pole connecting faces which are meshed with each other, accurate alignment of the modules in the radial direction and the circumferential direction is achieved, and accurate achievement of a dislocation angle theta and uniformity of an air gap are guaranteed.
  5. 5. The axial flux permanent magnet synchronous reluctance motor rotor based on modularized harmonic cancellation according to claim 1, wherein the fan-shaped rotor module is formed by riveting or laser welding after high-grade unoriented silicon steel sheets are laminated, or is integrally formed by adopting soft magnetic composite material SMC powder metallurgy.
  6. 6. The modularized harmonic cancellation-based axial flux permanent magnet synchronous reluctance motor rotor is characterized in that the protection device is a non-magnetic high-strength stainless steel sheath, the sheath is made of 304 stainless steel and is 0.8-1.2mm in thickness, the flat disc-shaped structure of the sheath, which is attached to the rotor, is sleeved on the outermost layer of the rotor and does not contact with an air gap between a stator and a rotor, the inner side of the sheath and the outer circular surface of a fan-shaped rotor module are fixed through high-temperature-resistant epoxy resin in an adhesive mode, and the high-temperature-resistant epoxy resin and the adhesive filled between the modules are of the same type.
  7. 7. The axial flux permanent magnet synchronous reluctance motor rotor based on modularized harmonic cancellation according to claim 1, wherein the adhesive is epoxy resin, preferably low-viscosity high-heat-conductivity epoxy resin, and the epoxy resin is filled and then subjected to vacuum defoaming and heat curing treatment, so that an integral body with the functions of structural strength, heat insulation and magnetism isolation is formed after curing.
  8. 8. The axial flux permanent magnet synchronous reluctance motor rotor based on modularized harmonic cancellation according to claim 1, wherein the permanent magnet group is a fan-shaped neodymium iron boron permanent magnet, preferably with the brand of N52SH, and the U-shaped magnetic barrier is embedded in a tangential magnetizing mode.
  9. 9. The axial flux permanent magnet synchronous reluctance motor rotor based on modularized harmonic cancellation according to claim 1, wherein an accurate radial uniform air gap is maintained between the end faces of the rotor assembly and the stator assembly, the air gap ranges from 0.3mm to 1.0mm, and the optimal value of the radial uniform air gap is 0.5mm +/-0.05 mm.
  10. 10. The axial flux permanent magnet synchronous reluctance motor rotor based on modularized harmonic cancellation according to any one of claims 1-9, wherein the structural design of the fan-shaped rotor module can flexibly adapt to different motor pole numbers, and harmonic cancellation of the corresponding pole number motor is achieved by adjusting the number N of the fan-shaped rotor modules and the optimal dislocation angle θ.

Description

Axial flux permanent magnet synchronous reluctance motor rotor based on modularized harmonic cancellation Technical Field The invention relates to the technical field of motors and electric transmission, in particular to an axial flux permanent magnet synchronous reluctance motor rotor based on modularized harmonic cancellation, which is suitable for motor application scenes requiring high efficiency, high fault tolerance and high torque density, such as new energy automobiles, industrial driving, aerospace, precision machinery and the like. Background The axial flux permanent magnet synchronous reluctance motor becomes the key development direction of the next generation of high-performance motors due to the advantages of compact axial size, high torque density, outstanding efficiency and the like, and has wide application prospect in the field of high-end power driving. However, the industrial application of the motor is still subject to the following technical bottlenecks which are not cooperatively solved for a long time: 1. Inherent electromagnetic vibration and noise problems This type of motor has both permanent magnet torque and reluctance torque components, the reluctance torque depends on the salient pole effect introduced by the rotor magnetic barrier, the periodicity of the magnetic barrier structure interacts with the stator tooth slot, and abundant space harmonics are excited in the air gap field, wherein the lower harmonics are the root cause of the periodic torque pulsation (including the tooth slot torque and the load torque pulsation). The significant torque ripple can cause unstable motor operation, cause noise and mechanical vibration, and seriously affect riding comfort and system service life in high-order applications such as electric automobiles. 2. Design contradiction between electromagnetic performance and mechanical strength In pursuit of high saliency and reluctance torque duty cycle, existing rotor designs tend to employ complex and fragile rotor flux-barrier topologies such as multi-layer, thin-walled "V" or "U" shaped composite structures. When the motor rotates at high speed, the structure can bear huge centrifugal stress, weak areas such as a magnetic bridge are extremely easy to generate plastic deformation and even fracture, and the reliability risk is caused, and if the magnetic bridge is thickened to improve the mechanical strength, the magnetic barrier effect is weakened, so that the electromagnetic performance of the motor is reduced, and the two are difficult to be compatible. 3. The manufacturing process is complex and the cost is high The traditional axial flux permanent magnet synchronous reluctance motor rotor is of an integral structure, and the inside of the rotor is complex special-shaped magnetic barrier grooves, particularly grooves with large depth and narrow width, so that extremely high requirements are provided for the precision of a stamping die of a silicon steel sheet, the lamination alignment process and the subsequent permanent magnet embedding process, and the production yield is low and the manufacturing cost is high. In addition, once the integral rotor is partially damaged, the integral rotor often needs to be replaced integrally, and the subsequent maintenance cost is high. At present, most of the existing improvement measures are single-dimension optimization, such as improving the waveform of an air gap magnetic field by optimizing the shape of a single magnetic barrier, or integrally forming a complex three-dimensional magnetic circuit by adopting a soft magnetic composite material (SMC), but the latter brings new problems of material cost and magnetic property stability. None of these solutions systematically solve the multiple contradictions between torque ripple, electromagnetic performance and mechanical strength, manufacturing process, so an innovative rotor design is needed that can fundamentally synergistically optimize the electromagnetic performance, mechanical reliability and manufacturing manufacturability of the motor. Disclosure of Invention The invention aims to overcome the technical defects of the existing axial flux permanent magnet synchronous reluctance motor rotor, provides an axial flux permanent magnet synchronous reluctance motor rotor based on modularized harmonic cancellation, and solves the problems of lower torque pulsation and electromagnetic noise by canceling main electromagnetic harmonic from the source through a systematic solution of three in one of structural modularization, gradient magnetic barrier and computability dislocation, simultaneously breaks down complex integral manufacture into precise machining and assembly of standardized units through modularized design, greatly reduces manufacturing cost and maintenance difficulty while improving mechanical reliability of the motor, and enables the rotor structure to flexibly adapt to different motor pole numbers and performance requirements, and cooperative