Axial winding complementary type hybrid excitation high-speed magnetic flux reversing motor

Abstract

The invention discloses an axial winding complementary type hybrid excitation high-speed magnetic flux reverse motor, and belongs to the technical field of power generation, power transformation or power distribution. The motor comprises a six-slot stator iron core, a four-tooth rotor iron core, a set of annular winding serving as an excitation winding and a set of concentrated winding serving as an armature winding, permanent magnet groups are attached to the inner surface of the tooth part of the stator core, two groups of axial permanent magnets are opposite in polarity, and two groups of circumferential permanent magnets are opposite in polarity; and the rotor iron core is formed by laminating a plurality of rotor iron core sections which have a mechanical angle of 45 degrees in the axial direction. The motor has the magnetic field adjusting capacity and has the advantages of being small in flux linkage, counter electromotive force sine, cogging torque and torque fluctuation, extra rising voltage caused by strong armature reaction during high-speed operation can be reduced through flux weakening, torque during low-speed operation can be improved through flux increasing, and due to the fact that the number of poles is small, loss is small during high-speed and high-frequency operation, and the motor is high in reliability. Compared with other magnetic flux reverse motors, the magnetic flux reverse motor is more suitable for high-speed operation.

Description

Technical Field

[0001] This invention relates to high-speed motor technology, and in particular discloses a high-speed flux reverse motor with complementary axial windings and hybrid excitation, belonging to the technical field of power generation, power transformation or power distribution. Background Technology

[0002] The flux-reversing motor is a type of stator permanent magnet motor. Its permanent magnets and windings are all located on the stator side, making it easy to arrange a cooling system for heat dissipation. The rotor has neither permanent magnets nor windings; it is made of stacked silicon steel sheets, resulting in a robust structure suitable for high-speed operation.

[0003] To achieve high-speed and high-efficiency operation of the motor, the fundamental frequency needs to be reduced, making a low pole pair scheme the preferred option. The minimum rotor pole number for a three-phase flux-reversing motor is 4, which can be adapted to 3 and 6 stator slots. However, a 3-slot 4-pole flux-reversing motor faces severe unbalanced magnetic pull, resulting in significant vibration and noise at high speeds, making it difficult to apply. A 6-slot 4-pole flux-reversing motor, on the other hand, does not have unbalanced magnetic pull. However, Xiaofen Zhu, in his 2019 article "Stator-Slot / Rotor-Pole Pair Combinations of Flux-Reversal Permanent MagnetMachine" published in the IEEE Industrial Electronics journal, argued that the severe asymmetric back EMF harmonics present in a conventional 6-slot 4-pole motor restricts its operation. Other researchers, in their 2021 paper "Low Harmonic Design and Electromagnetic Performance Analysis of Flux-Reversing Permanent Magnet Motor," also reached similar conclusions, concluding that a conventional 6-slot 4-pole flux-reversing motor is unusable.

[0004] In addition, low-slot motors face the challenge of strong armature reaction during high-speed operation under load, which causes a significant increase in terminal voltage. This limits the increase in motor speed and restricts further improvement in motor power density. Furthermore, it reduces the motor's power factor and increases the controller capacity.

[0005] In summary, the present invention aims to propose an axial winding complementary hybrid excitation high-speed flux reverse motor to overcome the defects of existing conventional high-speed flux reverse motor topologies, such as asymmetrical back electromotive force, large cogging torque / torque fluctuations, and power density limitation due to a significant increase in load operating voltage caused by strong armature reaction. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a high-speed flux reverse motor with complementary axial winding hybrid excitation. On the one hand, the invention aims to overcome the problems of magnetic flux asymmetry, back electromotive force asymmetry, large number of even harmonics, and large cogging torque / torque fluctuations that exist in this type of motor during high-speed operation. On the other hand, by adopting a hybrid excitation method, the magnetic field can be adjusted, which can overcome the problem of excessive high-end voltage limiting the speed / power density increase due to strong armature reaction during high-speed operation.

[0007] To achieve the above-mentioned objectives, the present invention employs the following technical solution:

[0008] Axial winding complementary hybrid excitation high-speed flux reverse motor includes: a 6-slot stator core, a 4-tooth rotor core, an armature winding, and an excitation winding. The armature winding is a concentrated winding evenly distributed around the circumference of the 6-slot stator core. The excitation winding is an annular winding formed on the outside of the stator core teeth and located between two adjacent stator core teeth. The 4-tooth rotor core is a segmented rotor core structure with axial mechanical angles differing by 45° and equal axial total length. Permanent magnet groups are attached to the inner surface of the stator core teeth. Any two axially adjacent permanent magnet groups have opposite polarities, and any two circumferentially adjacent permanent magnet groups have opposite polarities.

[0009] As a further optimization scheme for the axial winding complementary hybrid excitation high-speed flux reverse motor, one set of armature windings is a concentrated winding that is wound around the outside of the teeth of two adjacent stator cores and then evenly distributed along the circumference.

[0010] As a further optimization scheme for a hybrid excitation high-speed flux reverse motor with complementary axial windings, one armature winding is a concentrated annular winding that is wound axially on the yoke of the stator core and then evenly distributed along the circumference.

[0011] As a further optimization scheme for the axial winding complementary hybrid excitation high-speed flux reverse motor, the tooth tips and tooth roots on the outer side of each stator tooth are respectively provided with stator tooth excitation winding slots and stator yoke excitation winding slots for mounting the excitation windings.

[0012] As a further optimization of the axial winding complementary hybrid excitation high-speed flux reverse motor, the 6-slot stator core includes at least two segmented stator cores. Each segmented stator core is equipped with a set of armature windings and a set of excitation windings. The armature windings of each segmented stator core are connected in series, and the excitation windings of each segmented stator core are connected in series or in parallel.

[0013] As a further optimization of the axial winding complementary hybrid excitation high-speed flux reverse motor, the stator core teeth have slot insulation.

[0014] As a further optimization of the axial winding complementary hybrid excitation high-speed flux reverse motor, the segmented rotor core structure is fixed to the shaft by interference fit.

[0015] As a further optimization of the axial winding complementary hybrid excitation high-speed flux reverse motor, the segmented rotor core structure is made of silicon steel sheets or iron-cobalt-vanadium soft magnetic alloy laminations, with each layer of laminations positioned and fixed by adhesive bonding or riveting.

[0016] As a further optimization of the axial winding complementary hybrid excitation high-speed flux reverse motor, the permanent magnet assembly is magnetized by radial magnetization or parallel magnetization.

[0017] As a further optimization scheme for a hybrid excitation high-speed flux reverse motor with complementary axial windings, the direction of the DC current supplied to the excitation winding is adjusted to control the magnetization or weakening of the magnetization.

[0018] The present invention, by adopting the above technical solution, has the following beneficial effects:

[0019] (1) This invention improves the structure of a conventional 6-slot 4-pole flux reverse motor by combining the stator permanent magnet mounting and magnetization method with the segmented stacked axial deflection rotor. It utilizes the axial complementarity of the armature winding to compensate for the phase difference of the flux linkage / back EMF generated in the armature winding in the axial direction, significantly improves the sinusoidality of the flux linkage and back EMF, and reduces the main frequency of motor operation while realizing the high-speed operation of the 6-slot 4-pole flux reverse motor.

[0020] (2) By rationally arranging the excitation winding and armature winding on the stator side and by optimizing the winding method of the excitation winding and armature winding, the present invention overcomes the defects of limited number of turns and poor magnetic adjustment effect caused by the conventional excitation winding winding method of the existing hybrid excitation flux reverse motor. It realizes the magnetic adjustment of the constant permanent magnet magnetic field of the motor, which can further broaden the speed range of the motor under the voltage level limit and realize the power density improvement of the motor. Attached Figure Description

[0021] Figure 1(a) is a three-dimensional structural diagram of the axial winding complementary hybrid excitation high-speed flux reverse motor provided in Embodiment 1 of the present invention; Figure 1(b) is a structural diagram of the slotted stator side excitation winding of the axial winding complementary hybrid excitation high-speed flux reverse motor provided in Embodiment 1 of the present invention.

[0022] Figure 2 This is an exploded view of the axial shaft winding complementary hybrid excitation high-speed flux reverse motor provided in Embodiment 1 of the present invention.

[0023] Figure 3 This is a three-dimensional structural diagram of the axial winding complementary hybrid excitation high-speed flux reverse motor provided in Embodiment 2 of the present invention.

[0024] Figure 4 This is an exploded view of the axial winding complementary hybrid excitation high-speed flux reverse motor provided in Embodiment 2 of the present invention.

[0025] Figure 5 This is a three-dimensional structural diagram of the axial winding complementary hybrid excitation high-speed flux reverse motor provided in Embodiment 3 of the present invention.

[0026] Figure 6 The figure shows a comparison of the simulation results of the single-phase flux linkage waveform of the invented motor and the single-phase flux linkage waveform of a conventional reverse flux motor.

[0027] Figure 7 The figure shows a comparison of the simulation results of the single-phase back electromotive force waveform of the invented motor and the single-phase back electromotive force waveform of a conventional magnetic flux reverse motor.

[0028] Figure 8 The figure shows a comparison of the simulation results of the cogging torque waveform of the invented motor with that of a conventional magnetic flux reverse motor.

[0029] Figure 9 The figure shows a comparison of the simulation results of the torque fluctuation waveform of the invented motor with that of a conventional magnetic flux reverse motor.

[0030] Figure 10 The simulation results of the back electromotive force waveform of the invented motor under different excitation currents are shown in the figure.

[0031] The following are the labels in the diagram: 1. Stator core, 2. Armature winding, 3. Excitation winding, 4. Permanent magnet, 5. Rotor core, 6. Shaft, 1-1. Segmented stator core A section, 1-2. Segmented stator core B section, 1-101. Stator core yoke, 1-102. Stator core teeth section, 1-103. Slotted excitation winding in stator yoke section, 1-104. Slotted excitation winding in stator teeth section, 3-1. A set of excitation windings, 3-2. B set of excitation windings, 4-101. First group of N-pole permanent magnets, 4-102. First group of S-pole permanent magnets, 4-103. Second group of S-pole permanent magnets, 4-104. Second group of N-pole permanent magnets, 5-1. Segmented rotor core A section, 5-2. Segmented rotor core B section. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0034] Example 1

[0035] The axial winding complementary hybrid excitation high-speed flux reverse motor proposed in this embodiment is shown in Figure 1(a), Figure 1(b) and... Figure 2 As shown, it mainly includes: stator core 1, armature winding 2, excitation winding 3, permanent magnet 4, rotor core 5, shaft 6, a set of armature winding 2 and a set of excitation winding 3, with 6 stator slots and 4 rotor teeth.

[0036] The stator core 1 consists of six stator core components evenly distributed along the circumference. Each stator core component includes a stator yoke 1-101 and two stator teeth 1-102, which together form a stator slot. As shown in Figure 1(b), stator tooth excitation winding slots 1-104 and 1-103 for mounting the excitation winding 3 are respectively opened on the tooth tip and tooth root of each stator tooth 1-102. Two sets of permanent magnets are attached to the inner surface of each stator tooth 1-102. Any two adjacent sets of permanent magnets... The magnetization directions of the magnets are opposite. The first group of N-pole permanent magnets 4-101 and the first group of S-pole permanent magnets 4-102 form a permanent magnet group with opposite axial polarities. The second group of S-pole permanent magnets 4-103 and the second group of N-pole permanent magnets 4-104 form a permanent magnet group with opposite axial polarities. The first group of N-pole permanent magnets 4-101 and the second group of S-pole permanent magnets 4-103 form a permanent magnet group with opposite circumferential polarities. The first group of S-pole permanent magnets 4-102 and the second group of N-pole permanent magnets 4-104 form a permanent magnet group with opposite circumferential polarities. The permanent magnets are magnetized radially or in parallel.

[0037] One set of armature windings 2 is a concentrated winding structure, with the coils of each armature winding 2 wound on two adjacent stator core teeth, and all armature windings distributed on the same circumference. One set of excitation windings 3 is a ring winding structure, with each excitation winding wound tangentially in the radial direction on slots 1-103 of the stator yoke excitation winding and slots 1-104 of the stator tooth excitation winding, forming a ring winding located between two adjacent stator core teeth. The stator core teeth 1-102 have slot insulation for electrically isolating the excitation windings from the stator core. Slot insulation includes, but is not limited to, slot insulating paper, insulating coating, and insulating support.

[0038] The rotor core 5 is divided into two sections: section A (5-1) and section B (5-2). These sections are constructed from laminated silicon steel sheets or iron-cobalt-vanadium soft magnetic alloy laminations. Each lamination layer can be positioned and fixed by adhesive bonding or riveting. The two sections have an axial mechanical angle difference of 45° and equal total axial length. Sections A (5-1) and B (5-2) have internal circular holes for mounting the shaft, which is then fixed to the shaft 6 using an interference fit. The rotor teeth can be integrally potted, wound with carbon fiber or glass fiber, or fitted with alloy sheaths to form a cylindrical shape to reduce windage losses during high-speed operation.

[0039] Example 2

[0040] In this embodiment, the provided axial winding complementary hybrid excitation high-speed flux reversing motor is as follows: Figure 3 and Figure 4 As shown, its stator core 1 adopts a segmented structure. Segmented stator core A 1-1 and segmented stator core B 1-2 share the same armature winding 2. Segmented stator core A 1-1 and segmented stator core B 1-2 are wound with excitation winding A 3-1 and excitation winding B 3-2 respectively. Excitation winding A 3-1 and excitation winding B 3-2 are connected in series or parallel. Direct currents in opposite directions are applied to excitation winding A 3-1 and excitation winding B 3-2, and the direction of the direct current is adjusted according to the need for magnetization or magnetization weakening. Each stator tooth 1-102 has a set of permanent magnets mounted on its inner surface, with the magnetization directions of any two adjacent sets of permanent magnets opposite. Correspondingly, the rotor core also adopts a two-segmented structure, namely segmented rotor core A 5-1 and segmented rotor core B 5-2.

[0041] Example 3

[0042] In this embodiment, as follows: Figure 5 The axial winding complementary hybrid excitation high-speed flux reverse motor shown has one set of armature windings 2 as a concentrated ring winding structure. The stator core yoke 1-101 is transferred to the stator slot, and each armature winding 2 is uniformly wound axially on the stator core yoke 1-101 to form a ring winding. The armature windings are evenly arranged circumferentially to form a concentrated ring winding.

[0043] In one embodiment of the present invention, the stator core and rotor core can be segmented into a multi-segment structure. The segmented rotor cores are axially 45° apart by mechanical angle. Each segmented stator core has a set of armature windings connected in series. Each segmented stator core has a set of excitation windings connected in series and parallel to adapt to different voltage platforms and voltage adjustment and switching under different operating conditions.

[0044] In one embodiment of the present invention, the stator core 1 and the rotor core 5 are arranged as shown in Figures 1 to 5. Figure 5 The inner rotor structure shown can also be modified by moving the rotor core 5 to the outside of the stator core 1 to form an outer rotor structure.

[0045] Figure 6 A comparison of the simulation results of the three-phase flux linkage waveform of the invented motor with that of a conventional reverse flux motor shows that the flux linkage of the invented motor has a distinct sinusoidal characteristic. Its total harmonic distortion rate is reduced from 39% in the conventional reverse flux motor to 1.8%, making it easy to observe and control. It can transform an unusable motor structure into a usable one.

[0046] Figure 7 A comparison of the simulation results of the back EMF waveforms of the invented motor and those of a conventional flux-switched motor shows that, through the structural modification of this invention, the back EMF is improved from an unbalanced state to a balanced state in the conventional flux-switched motor, and the back EMF waveform tends to be sinusoidal. Its total harmonic distortion rate is reduced from 48.3% in the conventional flux-switched motor to 3.7%, thereby greatly improving the motor's controllability and addressing the serious loss problem.

[0047] Figure 8 A comparison of the simulation results of the cogging torque waveform of the invented motor with that of a conventional magnetic flux reverse motor shows that, after the structural modification of the present invention, the peak-to-peak value of the motor cogging torque is reduced from 15.8 Nm in the conventional motor to 0.28 Nm.

[0048] Figure 9 A comparison of the simulation results of the torque fluctuation waveform of the invented motor with that of a conventional magnetic flux reverse motor shows that, after the structural modification of the present invention, the average value of the motor torque is increased from 15.2 Nm to 15.4 Nm of the conventional motor, and the torque fluctuation is reduced from 222% to 14.3% of the conventional motor.

[0049] Figure 10 The simulation results of the back electromotive force waveform of the invented motor under different excitation currents show that the back electromotive force can be adjusted by 180% and -209% when the magnetizing ampere-turns are 200At and -200At, respectively, which can meet the needs of magnetizing under different operating conditions.

[0050] The above description is only a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. Any equivalent modifications or changes made by those skilled in the art based on the content disclosed in the present invention should be included in the scope of protection set forth in the claims.

Claims

1. An axial winding complementary hybrid excitation high-speed flux reverse motor, characterized in that, include: The stator core consists of a 6-slot stator core, a 4-tooth rotor core, an armature winding, and an excitation winding. The armature winding is a concentrated winding evenly distributed around the circumference of the 6-slot stator core. The excitation winding is an annular winding formed on the outside of the stator core teeth and located between two adjacent stator core teeth. The 4-tooth rotor core is a segmented rotor core structure with axial mechanical angles differing by 45° and equal total axial length. Permanent magnet groups are attached to the inner surface of the stator core teeth. Any two axially adjacent permanent magnet groups have opposite polarities, and any two circumferentially adjacent permanent magnet groups have opposite polarities.

2. The axial winding complementary hybrid excitation high-speed flux reversing motor according to claim 1, characterized in that, The armature winding is a concentrated winding that is wound around the outside of the teeth of two adjacent stator cores and then evenly distributed along the circumference.

3. The axial winding complementary hybrid excitation high-speed flux reversing motor according to claim 1, characterized in that, The armature winding is a concentrated ring winding that is wound axially on the yoke of the stator core and then evenly distributed around the circumference.

4. The axial winding complementary hybrid excitation high-speed flux reverse motor according to any one of claims 1 to 3, characterized in that, Each stator tooth has a slot for mounting the excitation winding at its tip and root.

5. The axial winding complementary hybrid excitation high-speed flux reversing motor according to claim 4, characterized in that, The 6-slot stator core includes at least two segmented stator cores. Each segmented stator core is equipped with a set of armature windings and a set of excitation windings. The armature windings of each segmented stator core are connected in series, and the excitation windings of each segmented stator core are connected in series or in parallel.

6. The axial winding complementary hybrid excitation high-speed flux reversing motor according to claim 4, characterized in that, The stator core teeth have slot insulation.

7. The axial winding complementary hybrid excitation high-speed flux reversing motor according to claim 4, characterized in that, The segmented rotor core structure is fixed to the shaft by an interference fit.

8. The axial winding complementary hybrid excitation high-speed flux reversing motor according to claim 4, characterized in that, The segmented rotor core structure is made of silicon steel sheets or iron-cobalt-vanadium soft magnetic alloy laminations, with each layer of laminations positioned and fixed by adhesive bonding or riveting.

9. The axial winding complementary hybrid excitation high-speed flux reversing motor according to claim 4, characterized in that, The permanent magnet assembly is magnetized using either radial magnetization or parallel magnetization.

10. The axial winding complementary hybrid excitation high-speed flux reversing motor according to claim 4, characterized in that, The direction of the DC current supplied to the excitation winding is adjusted to control the magnetization or weakening of the magnetization.

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