A high permanent magnet assisted synchronous reluctance motor rotor structure

Abstract

The application discloses a high permanent magnet auxiliary synchronous reluctance motor rotor structure, which comprises rotor punching sheets and a plurality of magnetic barrier groups arranged in the circumferential direction on the rotor punching sheets. d Each magnetic barrier group is composed of n layers of magnetic barriers arranged in the radial direction from the shaft center of the rotor punching sheet, and n cuboid ferrite permanent magnets are arranged in the direction of the shaft in the magnetic barriers. The application optimizes the rotor structure from the aspects of the size of the magnetic barrier, the number of the magnetic barrier layers, the magnetic conductive layer distribution of the rotor area, the size of the magnetic aid block, the thickness of the magnetic isolation bridge and the like, so as to improve the torque output and reduce the torque fluctuation, thereby improving the power density of the ferrite permanent magnet auxiliary synchronous reluctance motor and reducing the torque ripple.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of permanent magnet auxiliary synchronous reluctance motors, and particularly relates to a rotor structure of a high permanent magnet auxiliary synchronous reluctance motor. BACKGROUND

[0002] As a substitute for rare earth permanent magnet motors, ferrite auxiliary synchronous reluctance motors have wide application prospects in the field of marine motors. They are valued for protecting rare earth resources, reducing costs, and having the advantages of low price, environmental protection, high efficiency and reliability. However, ferrite auxiliary synchronous reluctance motors have some challenges in torque ripple, and some improvement measures need to be taken to solve the problem.

[0003] Ferrite auxiliary synchronous reluctance motors have the respective characteristics of synchronous reluctance motors and permanent magnet motors. They have the advantages of low cost, simple manufacturing process and high torque density, but also have the disadvantage of large torque ripple. Therefore, the suppression of torque ripple of ferrite auxiliary synchronous reluctance motors has always been a difficult problem for engineering and technical personnel.

[0004] At present, the suppression of torque ripple of ferrite auxiliary synchronous reluctance motors at home and abroad mainly suppresses torque ripple by adjusting the opening angle of the magnetic barrier end, changing the arrangement and shape of the ferrite, and selecting appropriate winding forms. However, the above optimization has not yet formed a systematic design theory.

[0005] In summary, ferrite auxiliary synchronous reluctance motors, as a new type of marine motor, have advantages in saving rare earth resources and reducing costs. However, the problem of torque ripple still needs to be solved, and the torque ripple needs to be suppressed by adjusting the opening angle of the magnetic barrier end, changing the arrangement and shape of the ferrite, and selecting appropriate winding forms. Further research and optimization can improve the performance and stability of the motor.

[0006] The conventional permanent magnet motor rotor structure has defects, and it is an urgent problem to propose a new rotor and magnetic pole structure that takes into account the advantages of simple structure and superior performance. SUMMARY

[0007] The application aims to solve the problems of low power density, large vibration, and rare earth permanent magnet scarcity in the prior art synchronous reluctance motor, and proposes a rotor structure of a ferrite permanent magnet auxiliary synchronous reluctance motor.

[0008] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention to solve the technical problem is: a high permanent magnet assisted synchronous reluctance motor rotor structure is located inside the stator, and the stator is composed of a stator core, a stator slot and a winding arranged in the stator slot; it includes a rotor punching and a plurality of magnetic barrier groups circumferentially arranged on the rotor punching, each magnetic barrier group is composed of n layers of magnetic barriers arranged radially from the axis of the rotor punching, and a rotor is established on the rotor. d 、 q Axis coordinate system, where d The positive direction of the axis is the direction of the rotor magnetic field from the N pole to the S pole. q Axis and d The angle between the axes is 36°. d Axis and q In the n-layer air magnetic barrier in each pole region of the axis, along d n (n<6) rectangular parallelepiped ferrite permanent magnets are respectively arranged in the direction of the axis.

[0009] In the high permanent magnet assisted synchronous reluctance motor rotor structure, the outer permanent magnets in each layer of magnetic barriers have equal thicknesses but unequal lengths.

[0010] In the high permanent magnet assisted synchronous reluctance motor rotor structure, the magnetic bridges of each layer of magnetic barriers are equal.

[0011] The high permanent magnet assisted synchronous reluctance motor rotor structure, each magnetic barrier group is composed of L 1 ~ L 3 It consists of three layers of magnetic barriers.

[0012] The high permanent magnet assisted synchronous reluctance motor rotor structure has a ferrite permanent magnet length along the magnetic barrier. L 1 Decreasing outwards, L 1 The ferrite permanent magnets in the layer magnetic barrier are composed of outer permanent magnets located on two radial lines and one or more inner permanent magnets perpendicular to the angle bisector of the two radial lines.

[0013] The high permanent magnet assisted synchronous reluctance motor rotor structure L 1 、 L 2 The ferrite permanent magnet in the magnetic barrier layer is composed of an inner permanent magnet and two outer permanent magnets connected end to end; L 3 The ferrite permanent magnets in the layer magnetic barrier are composed of two inner permanent magnets and two outer permanent magnets connected end to end.

[0014] The beneficial effects of the present invention are as follows: the present invention improves the magnetic barrier structure of the rotor punching sheet so that it can be better embedded in the ferrite permanent magnet material, thereby increasing the magnetic resistance effect; at the same time, the magnetic barrier size is optimized so that it adapts to the magnetic field distribution and improves the magnetic energy conversion efficiency; a suitable magnetic bridge structure is also designed to reduce magnetic field leakage and improve magnetic field concentration; through these improvements, the present invention can increase the output torque of the rotor and reduce torque pulsation, thereby improving the performance of the ferrite permanent magnet assisted synchronous reluctance motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the rotor punching of the present invention;

[0016] Figure 2 Schematic diagram of the structure of magnetic barriers and permanent magnets in rotor laminations;

[0017] Figure 3 is the torque output diagram of the permanent magnet synchronous motor;

[0018] Figure 4 This is the torque output diagram of the ferrite permanent magnet assisted synchronous reluctance motor. DETAILED DESCRIPTION

[0019] The present invention will be described in further detail below with reference to the accompanying drawings.

[0020] Reference Figure 1 、 Figure 2 As shown, the present invention discloses a high permanent magnet / high cost performance ferrite permanent magnet assisted synchronous reluctance motor rotor structure, which is located inside the stator. The stator is composed of a stator core, a stator slot and a winding arranged in the stator slot; it includes a rotor punching and a magnetic barrier group circumferentially arranged on the rotor punching, each magnetic barrier group is composed of n layers of magnetic barriers arranged radially from the axis of the rotor punching, and a rotor is established on the rotor of the 10-pole ferrite permanent magnet assisted synchronous reluctance motor. d 、 q Axis coordinate system, where d The positive direction of the axis is the direction of the rotor magnetic field from the N pole to the S pole. q Axis and d The angle between the axes is 36°. d Axis and q In the n (n<6) layers of air magnetic barriers in each pole region of the axis, along d N rectangular parallelepiped ferrite permanent magnets are respectively arranged in the direction of the axis. The magnetic bridges of the magnetic barriers in each layer are equal. The outer permanent magnets in each layer of the magnetic barriers have equal thicknesses and unequal lengths.

[0021] Specifically, each magnetic barrier group consists of L 1 ~ L 3It consists of three layers of magnetic barriers. The first layer of magnetic barriers from the center of the shaft to the stator is L 1 Layer, the outer side is L 2 、 L 3 Layer magnetic barrier, where L 1 The ferrite permanent magnets in the magnetic barrier layer are composed of outer permanent magnets located on two radial lines and one or more inner permanent magnets perpendicular to the angle bisector of the two radial lines. L 2 、 L 3 The outer permanent magnet and inner permanent magnet in the magnetic barrier are respectively L 1 The outer permanent magnets and the inner permanent magnets in the magnetic barrier are parallel. d 1 、 d 2 They are L 1 Layer and L 2 The thickness of the auxiliary permanent magnet block, where the inner permanent magnet block and the outer permanent magnet block provide permanent magnet torque T em for d Axis and q The magnetic barrier of the shaft provides reluctance torque T rm The length of the ferrite permanent magnet in the magnetic barrier is L 1 The lengths of the rectangular ferrite permanent magnets on the rotor area decrease gradually toward the outside.

[0022] Further, the L 1 、 L 2 The ferrite permanent magnet in the magnetic barrier layer is composed of an inner permanent magnet and two outer permanent magnets connected end to end; L 3 The ferrite permanent magnets in the layer magnetic barrier are composed of two inner permanent magnets and two outer permanent magnets connected end to end.

[0023] from Figure 3 、 Figure 4 It can be seen that for comparable output torque, the ferrite permanent magnet-assisted synchronous reluctance motor is more cost-effective and offers a higher torque performance / price ratio. The table below compares the cost differences between the two motors. The table shows that the cost difference between the two motors is primarily due to the magnets. The magnet cost of the new motor is only 1 / 10 of that of the original motor, representing a significant cost reduction.

[0024] .

[0025] The application optimizes the rotor structure by combining the features of the permanent magnet motor and the synchronous reluctance motor, mainly improves the magnetic barrier structure, the magnetic barrier size, the magnetic bridge structure and the like, changes the magnetic potential direction, improves the output torque and reduces the torque ripple, thereby improving the output torque of the ferrite permanent magnet auxiliary synchronous reluctance motor and the performance-price ratio of the motor.

[0026] The application can replace the permanent magnet synchronous motor with the same performance by using the ferrite permanent magnet auxiliary synchronous reluctance motor with lower cost, can greatly reduce the production cost of the motor, and has higher torque performance-price ratio than the permanent magnet motor, thereby being capable of overcoming the shortcomings of the existing synchronous reluctance motor and improving the performance-price ratio of the motor.

[0027] The above examples only exemplarily illustrate the principles and effects of the application and part of the applied examples, and for the ordinary skilled in the art, without departing from the concept of the application, a number of modifications and improvements can be made, which all belong to the protection scope of the application.

Claims

1. A high permanent magnet assisted synchronous reluctance machine rotor structure, characterized by: It includes rotor punchings and multiple magnetic barrier groups arranged circumferentially on the rotor punchings. Each magnetic barrier group consists of n layers of magnetic barriers arranged radially from the axis of the rotor punchings, establishing a synchronous d 、 q Axis coordinate system, where d The positive direction of the axis is the direction of the rotor magnetic field from the N pole to the S pole. q Axis and d The angle between the axes is 36°. d Axis and q In the n-layer magnetic barrier in each pole region of the axis, along d There are n rectangular ferrite permanent magnets arranged in the direction of the axis, n < 6, the magnetic bridges of each layer of magnetic barriers are equal, and each magnetic barrier group consists of L 1 ~ L 3 The magnetic barrier is composed of three layers, and the length of the ferrite permanent magnet in the magnetic barrier is along L 1 Decreasing outwards, L 1 The ferrite permanent magnets in the magnetic barrier layer are composed of outer permanent magnets located on two radial lines and one or more inner permanent magnets perpendicular to the angle bisector of the two radial lines. L 1 、 L 2 The ferrite permanent magnet in the magnetic barrier layer is composed of an inner permanent magnet and two outer permanent magnets connected end to end; L 3 The ferrite permanent magnets in the layer magnetic barrier are composed of two inner permanent magnets and two outer permanent magnets connected end to end.

2. A high permanent magnet assisted synchronous reluctance machine rotor structure according to claim 1, characterized in that, The thickness of the outer permanent magnets in each layer of magnetic barriers is equal, and the lengths are not equal.

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