Dual-stator hybrid excitation flux reversal motor based on DC bias

Abstract

The present invention provides a dual-stator hybrid excitation flux reversal motor based on DC bias, comprising an outer stator, an inner stator, and a rotor interposed between the inner and outer stators. The outer stator comprises an outer stator core, the inner circumference of which is uniformly distributed with multiple outer stator yokes, and an outer stator DC bias armature winding wound on the outer stator yokes. Each outer stator yoke extends a single outer stator tooth, and the outer stator teeth extend laterally from the outer stator pole shoes. The inner stator comprises an inner stator core, the outer circumference of which is provided with multiple inner stator yokes, and an inner stator armature winding wound on the inner stator yokes. Two inner stator teeth are provided at the extended end of the inner stator yoke, and an inner tooth slot is formed between the two inner stator teeth extending from the same inner stator yoke extended end. The inner stator permanent magnet is accommodated in the inner tooth slot. The rotor comprises multiple rotor core blocks. The present invention can achieve highly flexible magnetization and flux weakening control for the dual-stator flux reversal motor without separately providing a DC excitation winding.

Description

Technical Field

[0001] The present invention relates to the technical field of motor equipment control, and in particular to a dual-stator hybrid excitation flux reversal motor based on DC bias. Background Art

[0002] The main motors currently used are induction motors, wound-pole synchronous motors, and permanent magnet synchronous motors. Non-permanent magnet motors offer economic advantages but are lacking in performance. Hybrid excitation specialty motors, with their unique structure, offer outstanding performance and are the future direction of development. Summary of the Invention

[0003] The object of the present invention is to provide a dual-stator hybrid excitation flux reversal motor based on DC bias that can better meet the requirements of a low-speed, high-torque direct drive system.

[0004] To achieve the above object, the present invention provides a dual-stator hybrid excitation flux reversal motor based on DC bias, comprising:

[0005] An outer stator, comprising an outer stator core, the inner circumference of the outer stator core being uniformly distributed with a plurality of radially extending outer stator yokes, the outer stator DC bias armature winding being wound on the outer stator yokes, each outer stator yoke extending from a single outer stator tooth, the outer stator tooth extending laterally from an outer stator pole shoe;

[0006] an inner stator disposed within the outer stator, the inner stator comprising an inner stator core, a plurality of radially extending inner stator yokes disposed on the outer circumference of the inner stator core, an inner stator armature winding wound on the inner stator yoke, two inner stator teeth disposed at an extended end of the inner stator yoke, an inner tooth slot formed between two inner stator teeth extending from the same extended end of the inner stator yoke, and inner stator permanent magnets disposed within the inner tooth slots;

[0007] The rotor is sandwiched between the inner stator and the outer stator, and includes a plurality of rotor core blocks uniformly distributed along the circumferential direction.

[0008] In the dual-stator hybrid excitation flux reversal motor based on DC bias as described above, the slot fill rates of the outer stator DC bias armature winding and the inner stator armature winding are less than or equal to 60%.

[0009] In the dual-stator hybrid excitation flux reversal motor based on DC bias as described above, the air gap length between the outer stator and the rotor is equal to the air gap length between the rotor and the inner stator.

[0010] In the DC bias-based dual-stator hybrid excitation flux reversal motor as described above, the outer stator DC bias armature winding and the inner stator armature winding are both double-layer concentrated windings.

[0011] As described above, the dual-stator hybrid excitation flux reversal motor based on DC bias, wherein the DC bias is to pass AC and DC currents into the outer stator DC bias armature winding, the AC and DC current effective value ratio is variable, and the direction of the AC and DC currents is variable.

[0012] In the DC bias-based dual-stator hybrid excitation flux reversal motor as described above, the current density of the outer stator DC bias armature winding and the inner stator armature winding are equal.

[0013] In the dual-stator hybrid excitation flux reversal motor based on DC bias as described above, the radians of the outer stator teeth are equal, and the radians of the inner stator teeth are equal.

[0014] In the dual-stator hybrid excitation flux reversal motor based on DC bias as described above, the outer stator core, the inner stator core and the rotor core block are all formed by laminating silicon steel sheets.

[0015] As described above, the dual-stator hybrid excitation flux reversal motor based on DC bias, wherein the number of AC pole pairs of the outer stator DC bias armature winding is equal to the number of pole pairs of the inner stator armature winding; the number of DC pole pairs of the outer stator DC bias armature winding is equal to the number of pole pairs of the inner stator permanent magnet.

[0016] As described above, the DC bias-based dual-stator hybrid excitation flux reversal motor, wherein the relationship between the number of AC pole pairs of the outer stator DC bias armature winding, the number of poles of the rotor, and the number of pole pairs of the inner stator permanent magnet satisfies the vernier modulation calculation model.

[0017] In the dual-stator hybrid excitation flux reversal motor based on DC bias as described above, the vernier modulation calculation model is:

[0018] The vernier modulation calculation model is:

[0019] N r =kp PM ±p s

[0020] Among them, N r is the number of rotor poles, p PM is the number of pole pairs of the permanent magnet, p s is the number of pole pairs of the armature, k is an odd number, k = 1, 3, 5, ...

[0021] Compared with the prior art, the advantages of the present invention are as follows:

[0022] The DC bias-based dual-stator hybrid excitation flux reversal motor of the present invention combines a dual-stator topology with a vernier magnetic gear effect. The inner stator teeth and the rotor work together to regulate harmonics, ensuring high efficiency and high torque output of the motor.

[0023] In the dual-stator hybrid excitation flux reversal motor based on DC bias of the present invention, a combined AC and DC current is passed through the DC bias armature winding of the outer stator, which can realize the magnetization and weakening control of the motor without additionally setting up a pure DC excitation winding, greatly increasing the flexibility and weakening speed expansion capability of the motor; the curvature of the outer stator pole shoe is large, which increases the magnetic conductivity area of ​​the outer stator and increases the DC bias excitation effect; the inner stator maintains the AC armature winding, reducing the complexity of the motor; generally speaking, the dual-stator hybrid excitation flux reversal motor based on DC bias of the present invention realizes the hybrid excitation magnetic regulation function while maintaining torque output. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The following drawings are intended only to illustrate and explain the present invention, and are not intended to limit the scope of the present invention.

[0025] Figure 1 Schematic diagram of the structure of the dual-stator hybrid excitation flux reversal motor based on DC bias of the present invention;

[0026] Figure 2 This is the flux distribution diagram of the dual-stator hybrid excitation flux reversal motor based on DC bias;

[0027] Figure 3 The AC and DC input directions of the external stator DC bias armature windings (12 coils are labeled A1 to A4, B1 to B4, and C1 to C4) are marked;

[0028] Figure 4a The three-phase back electromotive force waveform diagram of the inner armature windings A, B, and C of the dual-stator hybrid excitation flux reversal motor of the present invention without DC bias; Figure 4b The figure is a waveform diagram of six groups of back electromotive force of three phases A, B and C of the outer armature winding of the dual-stator hybrid excitation flux reversal motor of the present invention without DC bias;

[0029] Figure 5 It is the electromagnetic torque waveform.

[0030] Description of Figure Numbers:

[0031] 1. External stator; 11. External stator core; 12. External stator yoke; 13. External yoke slot; 14. External stator DC bias armature winding; 15. External stator teeth; 16. External stator pole shoes;

[0032] 2. Inner stator; 21. Inner stator core; 22. Inner stator yoke; 23. Inner stator slots; 24. Inner stator armature winding; 25. Inner stator teeth; 26. Inner tooth slots; 27. Inner stator permanent magnets;

[0033] 3. Rotor; 31. Rotor core block. DETAILED DESCRIPTION

[0034] To provide a clearer understanding of the technical solutions, objectives, and effects of the present invention, specific embodiments of the present invention are now described with reference to the accompanying drawings. The use of the adjective or adverbial modifiers "inside" and "outside" is intended solely to facilitate relative reference between multiple groups of terms and does not describe any specific directional restrictions on the modified terms. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0035] like Figure 1 As shown, the present invention provides a dual-stator hybrid excitation flux reversal motor based on DC bias, which includes an outer stator 1, an inner stator 2 and a rotor 3, wherein:

[0036] An outer stator includes an outer stator core 11. The outer stator core 11 is annular. A plurality of radially extending outer stator yokes 12 are evenly distributed on the inner circumference of the outer stator core 11. That is, the plurality of outer stator yokes 12 are evenly spaced along the circumference of the outer stator core 11. An outer yoke slot 13 is formed between two adjacent outer stator yokes 12. Preferably, the outer yoke slot 13 is a semi-closed slot. An outer stator DC bias armature winding 14 is wound around the outer stator yoke 12 and can be accommodated in the outer yoke slot 13. A single outer stator tooth 15 extends from each outer stator yoke 12, and an outer stator pole shoe 16 extends laterally from each outer stator tooth 15.

[0037] The inner stator 2 is arranged inside the outer stator 1. The inner stator 2 includes an inner stator core 21. The inner stator core 21 is annular. The outer circumferential surface of the inner stator core 21 is provided with a plurality of inner stator yokes 22 corresponding to the outer stator yokes 12. That is, the plurality of inner stator yokes 22 are arranged at equal intervals along the circumference of the inner stator core 21, and the plurality of outer stator yokes 12 are arranged one-to-one with the plurality of inner stator yokes 22. An inner stator slot 23 is formed between two adjacent inner stator yokes 22. Preferably, the inner stator slot 23 is a semi-closed slot. An inner stator armature winding 24 is wound around the stator yoke 22. The inner stator armature winding 24 can be accommodated in the inner stator slots 23. Two inner stator teeth 25 are provided at the extended end of each inner stator yoke 22. An inner tooth slot 26 is formed between the two inner stator teeth 25 from the extended end of the same inner stator yoke 22. Preferably, the inner tooth slot 26 is an open slot, and the inner stator permanent magnet 27 is accommodated in the inner tooth slot 26. Furthermore, the inner stator permanent magnet 27 is radially magnetized, and the magnetization directions of adjacent inner stator permanent magnets 27 are opposite.

[0038] The rotor 3 is sandwiched between the inner stator 2 and the outer stator 1, and there are air gaps between the rotor 3 and the outer stator 1 as well as between the rotor 3 and the inner stator 2. Figure 3 As shown, the rotor 3 includes a plurality of rotor core blocks 31 uniformly distributed along the circumferential direction;

[0039] The dual-stator hybrid excitation flux reversal motor based on DC bias of the present invention combines the dual-stator structure with the vernier magnetic gear effect. The inner stator teeth and the rotor jointly play a harmonic regulation role, ensuring the high efficiency and high torque output of the motor.

[0040] In the dual-stator hybrid excitation flux reversal motor based on DC bias of the present invention, a combined AC and DC current is passed through the outer stator DC bias armature winding 14, which can realize the magnetization and weakening control of the motor without adding an additional DC excitation winding, greatly increasing the flexibility and weakening speed expansion capability of the motor; the curvature of the outer stator pole shoe 16 is large, which increases the magnetic conductive area of ​​the outer stator 1 and increases the DC bias excitation effect; the inner stator 2 maintains the AC armature winding to reduce the complexity of the motor; generally speaking, the dual-stator hybrid excitation flux reversal motor based on DC bias of the present invention realizes the hybrid excitation magnetic regulation function while maintaining torque output.

[0041] Furthermore, the slot fill rate of the outer stator DC bias armature winding 14 and the inner stator armature winding 24 is less than or equal to 60%, so as to ensure that the outer stator DC bias armature winding 14 and the inner stator armature winding 24 can be as far away from the edge of the air gap as possible when winding, so as to prevent AC losses such as skin effect and proximity effect.

[0042] Furthermore, the air gap length between the outer stator 1 and the rotor 3 and the air gap length between the rotor 3 and the inner stator 2 are equal. Preferably, the air gap length between the outer stator 1 and the rotor 3 and the air gap length between the rotor 3 and the inner stator 2 are both 0.6 mm.

[0043] Furthermore, both the outer stator DC bias armature winding 14 and the inner stator armature winding 24 are double-layer concentrated windings to reduce end windings, thereby lowering losses and winding difficulty.

[0044] Furthermore, the effective value ratio of the AC and DC currents of the outer stator DC bias armature winding 14 is variable, and the direction of the DC current passed through the outer stator DC bias armature winding 14 is variable to achieve different degrees of magnetization and magnetic weakening, greatly improving the flexibility of the motor; the current density of the outer stator DC bias armature winding 14 and the inner stator armature winding 24 are equal.

[0045] Furthermore, the outer stator core 11, the inner stator core 21 and the rotor core block 31 are all formed by laminating silicon steel sheets, and the inner stator permanent magnet 27 is made of neodymium iron boron material to facilitate the operation of the dual-stator hybrid excitation flux reversal motor based on DC bias.

[0046] Furthermore, the widths of the outer stator yokes 12 are equal, and the curvatures of the inner stator teeth 25 are equal, which facilitates processing and manufacturing.

[0047] Further, if Figure 3 As shown, each phase of the outer stator DC bias armature winding 14 is divided into two parts connected in series to achieve DC bias magnetization and flux weakening operation.

[0048] In one embodiment of the present invention, the number of AC pole pairs of the outer stator DC bias armature winding 14 is equal to the number of pole pairs of the inner stator armature winding 24; the number of DC pole pairs of the outer stator DC bias armature winding 14 is equal to the number of pole pairs of the inner stator permanent magnet 27; such a pole pair number setting enables the inner and outer stators to comply with the same magnetic field modulation pole pair number combination, reducing the design difficulty of the motor.

[0049] Furthermore, the relationship between the number of AC pole pairs of the outer stator DC bias armature winding 14 , the number of poles of the rotor 3 , and the number of pole pairs of the inner stator permanent magnet 27 satisfies the vernier modulation calculation model.

[0050] Furthermore, the vernier modulation calculation model is:

[0051] N r =kp PM ±p s

[0052] Among them, N r is the number of poles of rotor 3, p PM is the number of pole pairs of the inner stator permanent magnet 27 and the number of DC pole pairs of the outer stator DC bias armature winding 14, p s is the number of AC pole pairs of the outer stator DC bias armature winding 14 and the inner stator armature winding 24, k is an odd number, k = 1, 3, 5, ...

[0053] According to relevant application and performance requirements, the number of poles of the rotor 3 is 22, the number of pole pairs of the inner stator permanent magnet 27 and the number of DC pole pairs of the outer stator DC bias armature winding 14 are 6, the number of AC pole pairs of the outer stator DC bias armature winding 14 and the inner stator armature winding 24 is 4, and k is 3.

[0054] further, Figure 2 This is the flux distribution diagram of the dual-stator hybrid excitation flux reversal motor based on DC bias of the present invention, as shown in FIG. Figure 2As shown, it can be seen from the magnetic flux distribution that the number of AC pole pairs of the outer stator DC bias armature winding 14 and the inner stator armature winding 24 is 4, and the number of poles of the rotor 3 is 22. The magnetic field of the outer stator DC bias armature winding 14 with a low pole pair number and the inner stator armature winding 24 is modulated by the magnetic tuning ring structure of the rotor core block 31 of the proposed dual-stator hybrid excitation flux reversal motor based on DC bias, so as to obtain a harmonic magnetic field component that matches the magnetic field of the high pole pair number inner stator permanent magnet 27 and the DC excitation magnetic field of the outer stator DC bias armature winding 14, thereby forming an electromagnetic torque waveform; by making the AC / DC effective value ratio of the outer stator DC bias armature winding 14 variable and the direction of the DC current passed into the outer stator DC bias armature winding 14 variable, different degrees of magnetization and magnetic weakening can be achieved, thereby greatly improving the flexibility of the motor.

[0055] further, Figure 3 The AC and DC current directions of the external stator DC bias armature winding 14 (the three-phase 12 coils are marked as A1 to A4, B1 to B4, and C1 to C4) are marked. Figure 3 It can be seen that due to the different number of AC and DC pole pairs, in order to achieve DC bias modulation, the four coils in each phase are divided into two groups and connected in series. For phase A, windings A1 and A3 are connected in series as phase A group I, and A2 and A4 are connected in series as phase A group II. For phase B, windings B1 and B3 are connected in series as phase B group I, and B2 and B4 are connected in series as phase B group II. For phase C, windings C1 and C3 are connected in series as phase C group I, and C2 and C4 are connected in series as phase C group II.

[0056] further, Figure 4a The figure is a waveform diagram of the back electromotive force of the three windings A, B, and C of the inner armature winding of the dual-stator hybrid excitation flux reversal motor of the present invention without DC bias; Figure 4b The waveform diagram of the six back electromotive force waveforms of the outer armature windings A, B, and C of the dual-stator hybrid excitation flux reversal motor of the present invention without DC bias is formed by the rotor 3 rotating at a speed of 200 r / min, and the outer stator DC bias armature winding 14 and the inner stator armature winding 24 inducing three-phase symmetrical back electromotive force in the rotating magnetic field. For specific winding numbers, please refer to Figure 3 As described above, the distribution characteristics of the three-phase back electromotive force of the outer stator DC bias armature winding 14 and the inner stator armature winding 24 can be reflected in the state without DC bias. Figure 4a and Figure 4b As shown, the three-phase symmetry of the internal and external back EMF waveforms, the total back EMF effective value of each phase is 77V and 141V, and the performance meets the requirements of related applications.

[0057] further, Figure 5This is the electromagnetic torque waveform of the dual-stator hybrid excitation flux reversal motor based on DC bias of the present invention. The current density of the outer stator DC bias armature winding 14 and the inner stator armature winding 24 are equal. When the total current density is 6A / mm 2 In case of Figure 5 The figure shows that a DC current of 2A / mm is passed through the A1 coil of the external stator DC bias armature winding 14. 2 , -2A / mm 2 The output torque waveform under the condition of Figure 5 It can be seen that when the DC current is 2A / mm 2 Becomes -2A / mm 2 When the torque is reduced by 23%, the motor's significant magnetic adjustment capability is demonstrated, making its performance meet the requirements of related applications.

[0058] Specifically, the electromagnetic torque waveform is formed as follows: three-phase sinusoidal AC current is supplied to the outer stator DC-biased armature winding 14 and the inner stator armature winding 24. The rotating magnetic field drives the rotor 3 to rotate at a speed of 200 r / min. The magnetic field of the low-pole-pair-number outer stator DC-biased armature winding 14 and the inner stator armature winding 24 is modulated by the proposed DC-biased dual-stator hybrid excitation flux reversal motor's rotor core block 31 magnetic tuning ring structure. This modulates the magnetic field of the low-pole-pair-number outer stator DC-biased armature winding 14 and the inner stator armature winding 24, generating a harmonic magnetic field component that matches the magnetic field of the high-pole-pair-number inner stator permanent magnet 27 and the DC excitation magnetic field of the outer stator DC-biased armature winding 14, thereby forming the electromagnetic torque waveform.

[0059] In summary, the dual-stator hybrid excitation flux reversal motor based on DC bias of the present invention combines the dual-stator structure with the vernier magnetic gear effect. The inner stator teeth and the rotor jointly play a harmonic regulation role, ensuring the high efficiency and high torque output of the motor.

[0060] In the dual-stator hybrid excitation flux reversal motor based on DC bias of the present invention, a combined AC and DC current is passed through the DC bias armature winding of the outer stator, which can realize the magnetization and weakening magnetic field control of the motor without adding a pure DC excitation winding, greatly increasing the flexibility and weak magnetic field speed expansion capability of the motor; the curvature of the outer stator pole shoe is large, which increases the magnetic conductive area of ​​the outer stator and increases the DC bias excitation effect; the inner stator maintains the AC armature winding, reducing the complexity of the motor; generally speaking, the dual-stator hybrid excitation flux reversal motor based on DC bias of the present invention realizes the hybrid excitation magnetic regulation function while maintaining torque output.

[0061] The above description is only an illustrative embodiment of the present invention and is not intended to limit the scope of the present invention. Any equivalent changes and modifications made by any person skilled in the art without departing from the concept and principle of the present invention should fall within the scope of protection of the present invention. It should also be noted that the various components of the present invention are not limited to the above-mentioned overall application. The various technical features described in the specification of the present invention can be selected one by one or multiple features can be used in combination according to actual needs. Therefore, the present invention naturally covers other combinations and specific applications related to the invention point of this case.

Claims

1. A dual-stator hybrid excitation flux reversal motor based on DC bias, characterized in that: The dual-stator hybrid excitation flux reversal motor based on DC bias includes: An outer stator, comprising an outer stator core, the inner circumference of the outer stator core being uniformly distributed with a plurality of radially extending outer stator yokes, the outer stator DC bias armature winding being wound on the outer stator yokes, each outer stator yoke extending from a single outer stator tooth, the outer stator tooth extending laterally from an outer stator pole shoe; an inner stator disposed within the outer stator, the inner stator comprising an inner stator core, a plurality of radially extending inner stator yokes disposed on the outer circumference of the inner stator core, an inner stator armature winding wound on the inner stator yoke, two inner stator teeth disposed at an extended end of the inner stator yoke, an inner tooth slot formed between two inner stator teeth extending from the same extended end of the inner stator yoke, and inner stator permanent magnets disposed within the inner tooth slots; a rotor, which is sandwiched between the inner stator and the outer stator, and includes a plurality of rotor core blocks uniformly distributed along the circumferential direction; The DC bias is to pass AC and DC currents into the outer stator DC bias armature winding, the AC and DC current effective value ratio is variable, and the direction of the AC and DC currents is variable; The number of AC pole pairs of the outer stator DC bias armature winding is equal to the number of pole pairs of the inner stator armature winding; the number of DC pole pairs of the outer stator DC bias armature winding is equal to the number of pole pairs of the inner stator permanent magnet; The relationship between the number of AC pole pairs of the outer stator DC bias armature winding, the number of poles of the rotor, and the number of pole pairs of the inner stator permanent magnets satisfies a vernier modulation calculation model; The vernier modulation calculation model is: N r =kp PM ±p s Among them, N r is the number of rotor poles, p PM is the number of pole pairs of the permanent magnet, p s is the number of pole pairs of the armature, k is an odd number, k = 1, 3, 5, …….

2. The dual-stator hybrid excitation flux reversal motor based on DC bias according to claim 1, characterized in that: The slot fill rates of the outer stator DC bias armature winding and the inner stator armature winding are less than or equal to 60%.

3. The dual-stator hybrid excitation flux reversal motor based on DC bias according to claim 1, characterized in that: The length of an air gap between the outer stator and the rotor is equal to the length of an air gap between the rotor and the inner stator.

4. The dual-stator hybrid excitation flux reversal motor based on DC bias according to claim 1, characterized in that: The outer stator DC bias armature winding and the inner stator armature winding are both double-layer concentrated windings.

5. The dual-stator hybrid excitation flux reversal motor based on DC bias according to claim 1, characterized in that: The current density of the outer stator DC bias armature winding is equal to that of the inner stator armature winding.

6. The dual-stator hybrid excitation flux reversal motor based on DC bias according to claim 1, characterized in that: The radians of the outer stator teeth are equal, and the radians of the inner stator teeth are equal.

7. The dual-stator hybrid excitation flux reversal motor based on DC bias according to claim 1, characterized in that: The outer stator core, the inner stator core and the rotor core block are all formed by laminating silicon steel sheets.

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