High-performance modular permanent magnet hub motor

Abstract

The invention discloses a high-performance modular permanent magnet hub motor, and belongs to the technical field of permanent magnet motors. The motor comprises a plurality of stator modules and a consequent pole permanent magnet rotor, wherein the stator modules are uniformly arranged along the circumference to form a stator; the consequent pole permanent magnet rotor is formed by alternately arranging permanent magnets and salient pole iron cores; the stator module consists of a stator yoke part and stator teeth; a plurality of phases of armature windings are wound on the stator teeth; the small teeth at the ends of every two stator modules form a fault-tolerant tooth, and no winding is arranged on the fault-tolerant tooth. The problem of counter electromotive force even harmonics of a traditional modular consequent pole motor can be solved, even harmonic counter electromotive force is effectively eliminated, torque pulsation of the motor is restrained, and the output torque performance of the motor is improved; the fault-tolerant teeth can realize physical isolation between the stator modules, so that the operation reliability of the motor is improved; the fault-tolerant teeth reduce the effective air gap of the motor, and the torque density of the motor can be improved.

Description

Technical Field

[0001] This invention relates to the field of permanent magnet motor technology, and in particular to a high-performance modular permanent magnet hub motor. Background Technology

[0002] Permanent magnet motors, due to the use of rare-earth permanent magnet materials, possess advantages such as high torque density, high power density, and high efficiency, making them particularly suitable for transmission systems in new energy vehicles and wind power generation. Direct-drive hub motors, by eliminating the intermediate mechanical transmission system, are widely used in automotive distributed drive systems. In external rotor permanent magnet synchronous motors, the permanent magnets are typically placed on the external rotor; the permanent magnets are attached to the entire inner circle of the external rotor, resulting in a large amount of permanent magnets and back EMF even-order harmonic problems caused by the alternating pole permanent magnet rotor. Summary of the Invention

[0003] Purpose of the invention: The purpose of this invention is to provide a high-performance modular permanent magnet hub motor, which improves the utilization rate of permanent magnets, eliminates even harmonics of armature winding back EMF, and improves the output torque performance of the motor; at the same time, by adding auxiliary teeth in the large slots, physical isolation of the stator module is achieved, and the use of auxiliary teeth reduces the effective air gap of the motor, thereby improving the torque density of the motor.

[0004] Technical Solution: A high-performance modular permanent magnet hub motor, comprising several stator modules and alternating pole permanent magnet rotors, wherein each stator module is uniformly arranged along the circumference to form the stator; the alternating pole permanent magnet rotor is composed of alternating permanent magnets and salient pole iron cores; each stator module consists of a stator yoke and stator teeth, with several phase armature windings wound on the stator teeth; small teeth at the ends of every two stator modules form a fault-tolerant tooth, which has no windings; an independent air gap is formed between the alternating pole permanent magnet rotor and the stator modules; and there is a spacing between each stator module. , This represents the pole pitch of the motor.

[0005] Furthermore, the winding direction and sequence of the three-phase windings on each stator module are different.

[0006] Furthermore, the small tooth span between each stator module is By changing the winding sequence and direction of the windings on the stator module, the even harmonics of the back EMF in the armature windings that are in phase on two adjacent stator modules are ensured to cancel each other.

[0007] Furthermore, the small teeth at the ends of the stator modules ensure physical isolation between the modules.

[0008] Furthermore, the stator and rotor are made of silicon steel sheets axially stacked.

[0009] Furthermore, all permanent magnets are magnetized in the same direction, pointing towards the outside of the rotor or the stator.

[0010] Furthermore, using N S =2P±1 unit motor pole slot matching, N S denoted by , where is the number of slots in the unit motor, and P is the number of pole pairs in the unit motor.

[0011] Furthermore, the small teeth at the ends of the stator module adopt a structure with or without tooth tips.

[0012] Compared with the prior art, the significant advantages of this invention are as follows: 1. The stator of the present invention adopts modular production, which can be pre-wound on the stator module and then assembled, which facilitates motor processing, transportation and assembly; the small teeth at the end of the stator module can realize physical isolation between the modules, improve the reliability of motor operation; and reduce the risk of armature winding friction damage on the end teeth of the motor during transportation after winding. 2. The rotor of this invention adopts an alternating pole permanent magnet rotor, which can improve the utilization rate of permanent magnets, save permanent magnet materials and reduce motor costs; at the same time, it increases the inductance of the motor and effectively suppresses the short-circuit current of the motor. 3. The spacing between each stator module unit in this invention By changing the winding sequence and direction of the windings on the traditional stator module unit, the back EMF even harmonics in the armature windings of two adjacent stator module units that are in phase are canceled, thereby improving the output torque characteristics of the motor. 4. In this invention, auxiliary isolation teeth are added to the large slots formed between each stator module. The auxiliary teeth can reduce the effective air gap of the motor and increase the torque and power density of the motor. Attached Figure Description

[0013] Figure 1 These are traditional motor cross-sectional diagrams and winding connection diagrams; Figure 2 These are the motor cross-sectional view and winding connection diagram from Example 1; Figure 3 This is the stator labeling diagram of the modular motor in Example 1; Figure 4 This is a cross-sectional view of the auxiliary isolation teeth in the large slots between the modular stators of the motor in Example 1; Figure 5 These are the motor cross-sectional view and winding connection diagram in Example 2; Figure 6 The diagram shows the output electromagnetic torque waveforms of the traditional alternating pole motor and the two schemes in Example 1. Detailed Implementation

[0014] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0015] like Figure 1 As shown, a conventional motor includes an alternating pole permanent magnet rotor 1, alternating pole permanent magnets 2 on the rotor, an armature winding 4, a stator module 5, and an air gap 3 between the stator and the rotor.

[0016] Example 1 like Figure 2 As shown, this invention discloses a high-performance modular permanent magnet hub motor, comprising several stator modules 8 and alternating pole permanent magnet rotors. The alternating pole permanent magnet rotor has the same rotor structure as a traditional modular alternating pole permanent magnet motor; it consists of alternating permanent magnets 7 and salient pole iron cores 6; all permanent magnets are magnetized in the same direction, i.e., pointing towards the outside of the rotor or the stator side. Each stator module 8 consists of a stator yoke and stator teeth, with several phase armature windings 9 wound on the stator teeth; small teeth at the ends of every two stator modules form a fault-tolerant tooth 10. An independent air gap 11 is formed between the alternating pole permanent magnet rotor and the stator modules. The winding direction and sequence of the three-phase windings on each stator module are different. The spacing between each stator module unit is... , The pole pitch of the motor is N; the motor structure can adopt N S =2P±1 unit motor pole slot matching, N S Here, P represents the number of slots in the unit motor and P represents the number of pole pairs in the unit motor. This motor structure can solve the problem of even-order harmonics of back EMF in traditional modular alternating pole motors, effectively eliminating even-order harmonics of back EMF and effectively suppressing torque ripple. The fault-tolerant teeth 10 enable physical isolation between the various stator modules, improving the reliability of motor operation; the fault-tolerant teeth reduce the effective air gap of the motor, which can increase the torque density of the motor.

[0017] In this embodiment, the winding connection method of the motor is exactly the same as that of a traditional motor. The following describes the connection method in conjunction with... Figure 3 Detailed explanation: On stator module 8, three teeth are wound with A+, B+, and C+ windings in a counter-clockwise direction; on stator module 12, three teeth are wound with C-, B-, and A- windings in a counter-clockwise direction; the winding method for the remaining four stator modules (13, 14, 15, and 16) is as follows. Figure 2 The document provides specific markings, and the method for winding the motor coils is entirely based on the motor's back EMF star diagram.

[0018] Figure 4A structural diagram of the auxiliary isolation tooth (i.e., fault-tolerant tooth 10) is given. It is placed between adjacent stator modules, and the span of the auxiliary isolation tooth is... The electromagnetic performance of the motor can be optimized by optimizing the width of the auxiliary isolation teeth (17). In order to ensure that the slot areas on both sides of the large teeth on the stator module are equal, the width of the auxiliary isolation teeth cannot exceed [the specified value]. The polar distance width.

[0019] Example 2 As an alternative to Example 1, Figure 5 The following diagrams are provided for the cross-sectional view and winding connection of the modular permanent magnet hub motor with auxiliary isolation teeth without tooth tips in Embodiment 2. The armature winding connection method on the stator module teeth and the alternating pole permanent magnet rotor in Embodiment 2 are the same as in Embodiment 1. The difference lies in the small teeth at the end of the stator module, which have a tooth tip-less structure. This facilitates winding in the slots at the end of the stator module, making machine winding easier and improving production efficiency. Because the structure of Embodiment 2 is advantageous for machine winding of the motor, it is suitable for mass production. In this embodiment, the width of the auxiliary teeth is equal to... The polar distance width.

[0020] Figure 6 The output electromagnetic torque waveforms of two schemes, a traditional alternating pole motor and Example 1, are shown in the diagram. Figure 5 It can be seen that the average electromagnetic torque of the traditional motor is 6.02 Nm, while the average torque of the motor with auxiliary teeth is 6.51 Nm, representing an increase of 8.14% in average electromagnetic torque. The motor structure proposed in this invention can increase the output electromagnetic torque, which is beneficial for improving the motor's torque and power density.

[0021] The above embodiments are only for illustrating the technical concept of the present invention and should not be used to limit the scope of protection of the present invention. For example, the permanent magnets placed on the alternating pole rotor can have various structures (such as the Halbach structure with magnetic focusing effect). The present invention is illustrated using a three-phase motor as an example. The present invention patent can be extended to modular stator permanent magnet motors with M-phase pole slots. Any modifications made to the technical solution based on the technical concept proposed in the present invention fall within the scope of protection of the present invention.

Claims

1. A high-performance modular permanent magnet hub motor, characterized in that, It consists of several stator modules (8) and alternating pole permanent magnet rotors. Each stator module (8) is evenly arranged along the circumference to form a stator. The alternating pole permanent magnet rotor is composed of permanent magnets (7) and salient pole iron cores (6) arranged alternately. Each stator module consists of a stator yoke and stator teeth, with several phase armature windings (9) wound on the stator teeth. Small teeth at the ends of every two stator modules form a fault-tolerant tooth (10), which has no windings. An independent air gap (11) is formed between the alternating pole permanent magnet rotor and the stator module. The interval between each stator module is [missing information]. , The pole pitch of the motor.

2. The high-performance modular permanent magnet hub motor according to claim 1, characterized in that, The winding direction and sequence of the three-phase windings on each stator module are different.

3. The high-performance modular permanent magnet hub motor according to claim 1, characterized in that, The small tooth span between each stator module is By changing the winding sequence and direction of the windings on the stator module, the even harmonics of the back EMF in the armature windings that are in phase on two adjacent stator modules are ensured to cancel each other.

4. The high-performance modular permanent magnet hub motor according to claim 1, characterized in that, The small teeth at the ends of the stator modules ensure physical isolation between the modules.

5. The high-performance modular permanent magnet hub motor according to any one of claims 1-4, characterized in that, The stator and rotor are made of silicon steel sheets axially stacked.

6. The high-performance modular permanent magnet hub motor according to any one of claims 1-4, characterized in that, All permanent magnets are magnetized in the same direction, pointing towards the outside of the rotor or the stator.

7. The high-performance modular permanent magnet hub motor according to any one of claims 1-4, characterized in that, use N S =2 P ±1 unit motor pole slot matching N S The number of slots in a unit motor. P This represents the number of pole pairs of a unit motor.

8. The high-performance modular permanent magnet hub motor according to any one of claims 1-4, characterized in that, The small teeth at the end of the stator module have a toothed or toothless structure.

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