A high-torque-density double-winding permanent magnet motor based on magnetic gear effect

Abstract

The application discloses a high-torque-density double-winding permanent magnet motor based on a magnetic gear effect and relates to the technical field of motors.The application comprises a stator core, a fundamental wave winding, a harmonic wave winding, a modulation unit and a permanent magnet rotor; a half-closed slot is formed in the inner surface of the stator core, two sets of windings which are not coupled and have different pole pairs are placed in the slot, one set of the windings is the fundamental wave winding, and the other set of the windings is the harmonic wave winding; the modulation unit is composed of non-magnetic blocks and magnetic blocks which are alternately arranged along a circumference, is connected with the inner surface of the stator core, and only an air gap exists between the modulation unit and the permanent magnet rotor; the permanent magnet rotor is a magnetic gathering type permanent magnet rotor and comprises a tangential excitation permanent magnet and a magnetic separation slot structure. The two sets of windings can efficiently utilize the harmonic magnetic field and the fundamental wave magnetic field, the independent modulation unit is adopted to realize the optimal modulation ratio of the motor, the single air gap structure is beneficial to improving the working magnetic density of the motor, and the torque density of the motor driving system is effectively increased.

Description

A high torque density dual-winding permanent magnet motor based on magnetic gear effect Technical Field

[0001] This invention relates to the field of motor technology, specifically to a high torque density dual-winding permanent magnet motor based on the magnetic gear effect. Background Technology

[0002] Permanent magnet motors, with their advantages of high power density, high efficiency, and good controllability, have been widely used in industrial fields such as new energy vehicles, ship propulsion, and aerospace, placing higher demands on motor torque density. Traditional permanent magnet motors mainly achieve high torque density by increasing the electrical or magnetic load. Simply increasing the armature current to increase the electrical load can lead to demagnetization and magnetization, ultimately affecting the static characteristics of the motor. Increasing the magnetic load usually involves increasing the volume of the permanent magnet or adopting a concentrated magnet rotor structure, but this also has disadvantages such as low utilization of the permanent magnet and high torque ripple. In recent years, vernier permanent magnet motors and magnetic gear composite permanent magnet motors based on the magnetic gear effect have gradually emerged. These motors combine magnetic gears with traditional permanent magnet motors, using magnetic field speed increase to improve the motor's torque output capability. However, the increased torque density of vernier permanent magnet motors based on the magnetic gear effect has led to a lower power factor, requiring increased converter capacity, which in turn increases the cost and size of the motor system. Furthermore, these solutions only utilize a single harmonic magnetic field and part of the fundamental magnetic field to do work, neglecting part of the fundamental and other harmonic magnetic fields. Therefore, this invention proposes a high torque density dual-winding permanent magnet motor based on the magnetic gear effect. Summary of the Invention

[0003] The purpose of this invention is to provide a high torque density dual-winding permanent magnet motor based on the magnetic gear effect, which overcomes the shortcomings of traditional permanent magnet motors that cannot utilize harmonics and conventional magnetic gear effect permanent magnet motors that cannot simultaneously and efficiently utilize harmonics and fundamental waves to do work, thereby improving the torque density of the permanent magnet motor drive system.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a high torque density dual-winding permanent magnet motor based on the magnetic gear effect, comprising:

[0005] The stator core has a semi-closed slot on its inner surface. A fundamental wave winding and a harmonic winding are installed in the semi-closed slot. The fundamental wave winding and the harmonic winding are not coupled to each other and have different numbers of pole pairs.

[0006] A modulation unit is installed on the inner surface of the stator core. The modulation unit includes non-magnetic blocks and magnetic blocks, and the non-magnetic blocks and magnetic blocks are arranged alternately along the circumference.

[0007] A permanent magnet rotor is rotatably connected inside the stator core. A tangentially excitable permanent magnet is installed on the permanent magnet rotor. A magnetic isolation groove is opened on the side wall of the permanent magnet rotor, and the magnetic isolation groove is located at the end of the tangentially excitable permanent magnet near the center of the permanent magnet rotor.

[0008] Furthermore, both the fundamental winding and the harmonic winding are connected in a star configuration. The armature magnetic field generated by the fundamental winding is coupled with the fundamental excitation magnetic field generated by the permanent magnet rotor to generate a fundamental torque component. The turn-chain difference of the harmonic winding modulates the harmonic magnetic field to generate a harmonic torque component.

[0009] Furthermore, the fundamental winding and the harmonic winding have the same phase current angular frequency but opposite phase sequence, and both are driven by the same four-quadrant converter.

[0010] Furthermore, there is no air gap between the modulation unit and the stator core; the air gap exists only between the modulation unit and the permanent magnet rotor.

[0011] Furthermore, the number of pole pairs P of the fundamental winding, the number of pole pairs Q of the harmonic winding, and the number of poles N of the magnetic block are... s The following conditions must be met:

[0012] N s = (1+2n)Q or N s = (1+3n)Q

[0013] N s =P+Q

[0014] In the formula, n = 1, 2, 3, ...

[0015] Furthermore, the armature magnetic fields generated by the fundamental and harmonic windings interact with the excitation magnetic field generated by the permanent magnet rotor to produce electromagnetic torque, which is the fundamental torque component T. f With harmonic torque component T h Total electromagnetic torque T r satisfy:

[0016]

[0017] Where e i (t) and e j (t) represent the opposite electromotive forces of the fundamental and harmonic windings, respectively, i i (t) and i j (t) represents the phase currents of the fundamental and harmonic windings, i = A / B / C, j = U / V / W, and ω. r It represents the angular speed of the permanent magnet rotor.

[0018] Furthermore, the angular speed ω of the permanent magnet rotor r ω, armature magnetic field speed of fundamental winding fHarmonic winding armature magnetic field angular speed ω h The fundamental winding has P pole pairs, and the modulation unit has N magnetic blocks with N poles. s The fundamental winding current frequency f s Harmonic winding current frequency f h satisfy:

[0019]

[0020] f s =f h .

[0021] Furthermore, the tangentially excitable permanent magnet possesses the magnetic focusing effect of a traditional spoke-type permanent magnet rotor, and the bottom of the tangentially excitable permanent magnet and the magnetic isolation groove have a unilateral magnetic shielding effect.

[0022] Furthermore, the permanent magnet rotor type is one of the following: spoke rotor, embedded rotor, alternating pole rotor, V-type rotor, built-in V-type rotor, U-type rotor, Halbach type rotor, and a hybrid rotor of spoke and embedded types.

[0023] This invention has at least the following beneficial effects:

[0024] (1) Since the existing permanent magnet motor technology cannot effectively utilize the air gap harmonic magnetic field, resulting in the insufficient space for torque density improvement, the present invention places two sets of windings with different pole pairs on the same stator, and efficiently utilizes the fundamental and harmonic magnetic fields of the permanent magnet motor to do work. This overcomes the defects of traditional permanent magnet motors that cannot utilize harmonics and conventional permanent magnet motors based on magnetic gear effect that cannot simultaneously and efficiently utilize harmonics and fundamental waves to do work, and effectively improves the torque density of the permanent magnet motor drive system.

[0025] (2) In view of the problem of high magnetic circuit reluctance and low torque output capability in the existing permanent magnet motor technology based on magnetic gear effect, the present invention adds an independent modulation unit structure between the stator and the rotor to form a magnetic gear torque increase effect. The magnetic conductive block and non-magnetic conductive block of the modulation unit are embedded in the inner side of the stator after being combined, eliminating the air gap between the stator and the magnetic adjustment ring, forming a single air gap permanent magnet motor structure based on magnetic gear effect, reducing structural complexity and process cost, reducing magnetic flux path reluctance, and increasing air gap magnetic density.

[0026] (3) In view of the problem that the existing permanent magnet motor technology uses two sets of drivers for the dual windings, resulting in large size and high cost of the motor drive system, the present invention has two independent windings with different pole pairs in the stator, which do not have direct coupling. They are driven centrally by the same four-quadrant converter, which improves the torque density of the motor drive system. In addition, the permanent magnet rotor is a magnetically concentrated structure with alternating tangential and radial excitation, which is conducive to increasing the magnetic load of the motor, reducing end leakage flux, improving air gap magnetic flux density, improving the utilization rate of rotor permanent magnet material, and increasing the mechanical strength of permanent magnet rotor and system reliability.

[0027] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0028] Figure 1 is a schematic diagram of the overall structure of the present invention;

[0029] Figure 2 is a schematic diagram of the effect of the fundamental winding and permanent magnet rotor constituting a conventional permanent magnet synchronous motor in this invention.

[0030] Figure 3 is a schematic diagram of the magnetic gear composite motor effect formed by the harmonic winding, modulation unit and permanent magnet rotor in this invention.

[0031] Figure 4 is a structural diagram of the modulation unit in this invention;

[0032] Figure 5 is a schematic diagram of the permanent magnet rotor structure in this invention;

[0033] Figure 6 is a schematic diagram of the drive system topology of the corresponding motor in the overall structure of Figure 1;

[0034] Figure 7 is a schematic diagram of the series-parallel connection of the fundamental and harmonic windings of the corresponding motor in the overall structure of Figure 1.

[0035] Figure 8(a) is a schematic diagram of the parallel connection of the motor windings corresponding to Figure 1;

[0036] Figure 8(b) is a schematic diagram of the series connection of the motor windings corresponding to Figure 1;

[0037] Figure 9 shows the relationship between the fundamental winding, harmonic winding, and air gap magnetic field;

[0038] Figure 10 shows the electromagnetic torque of the corresponding motor and the electromagnetic torque of a conventional permanent magnet synchronous motor in the overall structure of Figure 1 under rated conditions.

[0039] Figure 11 shows the induced electromotive force of the fundamental and harmonic windings of the motor in the overall structure of Figure 1.

[0040] Figure 12 shows the self-inductance and mutual inductance of the fundamental and harmonic windings of the motor in the overall structure of Figure 1.

[0041] Figure label:

[0042] 1. Stator core; 2. Fundamental winding; 3. Harmonic winding; 4. Modulation unit; 5. Permanent magnet rotor; 6. Tangential excitation permanent magnet; 7. Magnetic isolation slot; 8. Magnetic guide block; 9. Non-magnetic guide block; 10. Converter. Detailed Implementation

[0043] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0044] As shown in Figure 1, the present invention provides a high torque density dual-winding permanent magnet motor based on magnetic gear effect, including a stator core 1, a semi-closed slot 11 on the inner surface of the stator core 1, a fundamental wave winding 2 and a harmonic winding 3 installed in the semi-closed slot 11, the fundamental wave winding 2 and the harmonic winding 3 are not coupled to each other and have different numbers of pole pairs.

[0045] The modulation unit 4 is installed on the inner surface of the stator core 1. The modulation unit 4 includes a non-magnetic block 98 and a magnetic block 8, and the non-magnetic block 98 and the magnetic block 8 are arranged alternately along the circumference.

[0046] The permanent magnet rotor 5 is rotatably connected inside the stator core 1. A tangentially excitable permanent magnet 6 is installed on the permanent magnet rotor 5. A magnetic isolation groove 7 is opened on the side wall of the permanent magnet rotor 5, and the magnetic isolation groove 7 is located at the end of the tangentially excitable permanent magnet 6 near the center of the permanent magnet rotor 5.

[0047] As shown in Figure 2, the fundamental winding 2 and the permanent magnet rotor 5 form a conventional permanent magnet synchronous motor effect. Figure 3 shows that the harmonic winding 3, the modulation unit 4, and the permanent magnet rotor 5 form a magnetic gear composite motor effect.

[0048] As shown in Figure 4, the modulation unit 4 consists of non-magnetic blocks 98 and magnetic blocks 8 arranged alternately along the circumference, which changes the air gap magnetic permeability and reconstructs the air gap magnetic field. The structure of the magnetic block 8 is related to the modulation effect of the air gap magnetic field, and the number of poles of the magnetic block 8 is N. s Furthermore, the polar arc coefficient is set to 0.4-0.6. Preferably, in the scheme adopted by the present invention, the polar arc coefficient of the magnetic block 8 is designed to be 0.42, and the radial thickness of the magnetic block 8 is 4mm.

[0049] As shown in Figure 5, the permanent magnet rotor 5 is a magnetizing rotor structure, including a tangentially excitation permanent magnet 6 and a magnetic isolation slot 7. In actual use, depending on the arrangement and magnetization method of the permanent magnets, the magnetizing rotor type of the permanent magnet rotor 5 can be one of the following: a spoke rotor, an embedded rotor, an alternating pole rotor, a V-type rotor, an internal V-type rotor, a U-type rotor, a Halbach-type rotor, or a hybrid rotor of spoke and embedded types. For the technical solution in this application, the permanent magnet rotor 5 is set to a spoke rotor type.

[0050] As shown in Figure 6, the fundamental winding 2 and the harmonic winding 3 have the same phase current angular frequency but opposite phase sequence, and are driven by the same four-quadrant converter 10.

[0051] As shown in Figure 7, the fundamental winding 2 and harmonic winding 3 are connected in series and parallel, with both windings sharing a common input terminal. This helps reduce costs, simplify the control strategy, and lower the DC bus voltage. Figures 8(a) and 8(b) show the parallel and series connections of the motor windings corresponding to Figure 1, respectively. In the parallel connection, the two windings have independent input terminals and independent neutral points. Although this can lower the bus voltage, each winding must be equipped with an independent converter to accurately calculate the phase current for motor control, which inevitably increases costs. In the series connection, the two windings share the same input terminal and have only one neutral point. A single frequency converter can be used to control the motor, which helps reduce costs and simplify the control strategy, but increases the bus voltage.

[0052] The excitation magnetic field generated by the permanent magnet rotor 5, after being modulated by the modulation unit 4, mainly produces a rotating magnetic field with fundamental component, modulation harmonic component, and differential modulation harmonic component in the stator side air gap, and the radial component B of the magnetic induction intensity. ri It can be represented as:

[0053]

[0054] In the formula, a r The radial component amplitude of the air gap magnetic flux density provided for the unmodulated permanent magnet rotor 5, where c0 and c1 are modulation coefficients, θ is the mechanical angle of the circumferential position, and ω r For a permanent magnet rotor, the angular velocity is 5, θ r0 Let θ be the initial angle of the rotor. m0 The initial angle of the excitation magnetomotive force is given by P, where P is the number of pole pairs of the fundamental magnetic field (rotor rotating magnetic field) and (N... s +P r ) is the number of pole pairs of the modulated harmonic magnetic field, (N s -P r The number of pole pairs of the modulated harmonic magnetic field.

[0055] The radial component B of magnetic induction intensityri The coefficients of the time variable t in the expression show that the angular frequencies of the fundamental magnetic field, the modulated harmonic magnetic field, and the differential modulated harmonic magnetic field are equal. The rotation direction of the fundamental magnetic field is the same as that of the modulated harmonic magnetic field and opposite to that of the differential modulated harmonic magnetic field.

[0056] The stator core 1 has two independent windings: a fundamental winding 2 with 14 pole pairs (P=14) and a harmonic winding 3 with 1 pole pair (Q=1), and a magnetic block 8 with N poles. s =15, satisfying N s = (1+2n)Q or N s = (1+3n)Q, N s =P+Q, where n=1,2,3…; The armature magnetic fields generated by the fundamental winding 2 and the harmonic winding 3 interact with the excitation magnetic field generated by the permanent magnet rotor 5 to produce electromagnetic torque, which are the fundamental torque components T. f With harmonic torque component T h Total electromagnetic torque T r satisfy:

[0057]

[0058] Where e i (t) and e j (t) represents the back electromotive force of the fundamental winding 2 and the harmonic winding 3, respectively. i (t) and i j (t) represents the phase currents of the fundamental winding 2 and the harmonic winding 3, respectively, i = A / B / C, j = U / V / W, ω r The rotational speed is 5 degrees for the permanent magnet rotor.

[0059] It should be noted that the 5-degree rotational speed ω of the permanent magnet rotor r 2. Armature magnetic field angular speed ω of fundamental winding 2 f Harmonic winding 3 armature magnetic field angular speed ω h The fundamental winding has 2 pole pairs (P), and the modulation unit has 4 magnetic blocks with 8 poles (N). s The fundamental winding 2 current frequency f s Harmonic winding 3 current frequency f h satisfy:

[0060]

[0061] f s =f h

[0062] Figure 9 shows a schematic diagram of the relationship between the stator winding and the air gap magnetic field. If a single pair of very short-pitch windings is used, neither a single pair of pole magnetic fields nor a 14-pitch magnetic field is fully utilized. When the number of pole pairs in the fundamental winding 2 is P = 2na and the number of pole pairs in the harmonic winding 3 is Q = a, n = 1, 2, 3…, the flux linkage generated by coupling the magnetic field of the harmonic winding 3 within one pole pitch of the fundamental winding 2 is zero, and the flux linkage generated by coupling the magnetic field of the fundamental winding 2 within one pole pitch of the harmonic winding 3 is also zero. There is no direct coupling between the two sets of windings, satisfying…

[0063]

[0064] Where ψ f (t) and ψ h (t) represent the flux linkages of the fundamental winding 2 and the harmonic winding 3, respectively. g L is the air gap radius. a For motor stacking thickness, B f and B h The air gap magnetic flux density (N) generated by the fundamental winding 2 and the harmonic winding 3 are respectively. f and N h These are the winding functions of the fundamental winding 2 and the harmonic winding 3, respectively.

[0065] When Q = a and P = 3a, the electromotive force generated by the magnetic field of harmonic winding 3 within one pole pitch of fundamental winding 2 is not zero. The flux linkage of fundamental winding 2 caused by the harmonic magnetic field of the windings can be expressed as:

[0066]

[0067] Where N a For the fundamental winding with 2 turns, ω h The rotational speed of the harmonic winding 3 is equivalent to introducing a third harmonic into the fundamental winding 2. If the fundamental winding 2 is connected in a star configuration, the third harmonic can be eliminated. Therefore, the selection of the number of pole pairs for the two windings can satisfy the following conditions.

[0068]

[0069] As shown in Figure 10, under the same volume, air gap surrounding volume, permanent magnet volume and electrical load conditions, the electromagnetic torque of the high torque density dual-winding permanent magnet motor based on magnetic gear effect provided by the present invention is compared with the electromagnetic torque of a conventional permanent magnet synchronous motor; Figure 11 is the induced electromotive force of the fundamental winding 2 and harmonic winding 3 of the motor corresponding to Figure 1; Figure 12 is the self-inductance and mutual inductance of the fundamental winding 2 and harmonic winding 3 of the motor corresponding to Figure 1.

[0070] It should be noted that the tangentially excitable permanent magnet 6 in the permanent magnet rotor 5 has the magnetic focusing effect of the traditional spoke-type permanent magnet rotor 5, and the bottom of the tangentially excitable permanent magnet 6 and the magnetic isolation groove 7 have a unilateral magnetic shielding effect, which can reduce the leakage flux at the radial end of the spoke-type permanent magnet.

[0071] In summary, by setting the fundamental winding 2 and the harmonic winding 3, this application can efficiently utilize the harmonic magnetic field and the fundamental magnetic field, adopt an independent modulation unit 4 to achieve the optimal modulation ratio of the motor, and the single air gap structure is conducive to improving the working magnetic flux density of the motor, effectively increasing the torque density of the motor drive system.

[0072] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0073] For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances. When an element is referred to as being "assembled on," "mounted on," "fixed to," or "set on" another element, it may be directly on the other element or there may be an intermediate element present. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible embodiments.

[0074] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

[0075] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

Claims

1. A high torque density dual-winding permanent magnet motor based on the magnetic gear effect, characterized in that, include: Stator core (1), the inner surface of the stator core (1) has a semi-closed slot, and the fundamental wave winding (2) and harmonic winding (3) are installed in the slot. The fundamental wave winding (2) and harmonic winding (3) are not coupled to each other and have different numbers of pole pairs. A modulation unit (4) is installed on the inner surface of the stator core (1). The modulation unit (4) includes a non-magnetic block (9) and a magnetic block (8), which are arranged alternately along the circumference. A permanent magnet rotor (5) is rotatably connected inside the stator core (1). A tangential excitation permanent magnet (6) is installed on the permanent magnet rotor (5). A magnetic isolation groove (7) is opened on the side wall of the permanent magnet rotor (5), and the magnetic isolation groove (7) is located at one end of the tangential excitation permanent magnet (6) near the center of the permanent magnet rotor (5). The armature magnetic fields generated by the fundamental winding (2) and the harmonic winding (3) interact with the excitation magnetic field generated by the permanent magnet rotor (5) to generate electromagnetic torque, which are the fundamental torque components T. f With harmonic torque component T h Total electromagnetic torque T r satisfy: Where e i (t) and e j (t) represents the opposite electromotive force of the fundamental winding (2) and the harmonic winding (3), respectively. i (t) and i j (t) represents the phase currents of the fundamental winding (2) and the harmonic winding (3), respectively, i=A / B / C, j=U / V / W, ω r The angular speed of the permanent magnet rotor (5) is angular speed.

2. The high torque density dual-winding permanent magnet motor based on magnetic gear effect according to claim 1, characterized in that: The fundamental winding (2) and the harmonic winding (3) are both connected in a star configuration. The armature magnetic field generated by the fundamental winding (2) is coupled with the fundamental excitation magnetic field generated by the permanent magnet rotor (5) to generate a fundamental torque component. The harmonic winding (3) links the differential modulation harmonic magnetic field generated by the permanent magnet rotor (5) to generate a harmonic torque component.

3. The high torque density dual-winding permanent magnet motor based on magnetic gear effect according to claim 2, characterized in that: The fundamental winding (2) and the harmonic winding (3) have the same phase current angular frequency and opposite phase sequence, and are driven by the same four-quadrant converter (10).

4. A high torque density dual-winding permanent magnet motor based on magnetic gear effect according to claim 1, characterized in that: There is no air gap between the modulation unit (4) and the stator core (1), and there is only an air gap between it and the permanent magnet rotor (5).

5. A high torque density dual-winding permanent magnet motor based on magnetic gear effect according to claim 3, characterized in that: The fundamental winding (2) has a pole pair number P, the harmonic winding (3) has a pole pair number Q, and the magnetic block (8) has a pole number N. s The following conditions must be met: N s = (1+2n)Q or N s =(1+3n)QN s =P+Q, where n=1,2,3….

6. A high torque density dual-winding permanent magnet motor based on magnetic gear effect according to any one of claims 5, characterized in that: The permanent magnet rotor (5) has an angular rotational speed ω r 1. Fundamental winding (2) Armature magnetic field angular speed ω f Harmonic winding (3) Armature magnetic field angular speed ω h The fundamental winding (2) has a pole pair count P, and the modulation unit (4) has a magnetic block (8) with a pole count of N. s , Fundamental winding (2) Current frequency f s Harmonic winding (3) current frequency f h satisfy: 。 7. A high torque density dual-winding permanent magnet motor based on magnetic gear effect according to claim 1, characterized in that: The tangentially excitable permanent magnet (6) has the magnetic focusing effect of the spoke-type permanent magnet rotor (5), and the bottom of the tangentially excitable permanent magnet (6) and the magnetic isolation groove (7) have a unilateral magnetic shielding effect.

8. A high torque density dual-winding permanent magnet motor based on magnetic gear effect according to claim 1, characterized in that: The permanent magnet rotor (5) is an embedded rotor of the magnetizing rotor type.

Images