High reluctance torque utilization positive saliency enhanced hybrid magnet pole permanent magnet machine
By introducing a flux-regulated rotor pole unit with adjustable air gap characteristics and an inductor-regulated rotor pole unit with high saliency ratio characteristics into a hybrid permanent magnet motor, the problem of insufficient low-speed torque output of a leakage flux controllable permanent magnet motor is solved, achieving efficient full-speed range operation and improved torque output capability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- NANTONG UNIV
- Filing Date
- 2026-03-10
- Publication Date
- 2026-05-12
AI Technical Summary
Existing leakage flux controllable permanent magnet motors have insufficient torque output capability under low-speed conditions, which limits their application in practical electric vehicles.
A hybrid permanent magnet motor with high reluctance torque utilization and positive salient pole enhancement is designed. It adopts a flux-regulated rotor pole unit with adjustable air gap and an inductor-regulated rotor pole unit with high salient pole ratio to form a hybrid pole motor rotor structure. Through the synergistic effect of the flux regulation and inductor regulation units, the reluctance torque utilization rate at low speed is improved, and wide speed regulation operation is achieved at high speed.
It significantly improves the utilization rate of reluctance torque at low speeds, overcomes the problems of reduced inductance difference and insufficient torque output caused by quadrature axis magnetic circuit saturation in traditional leakage flux controllable permanent magnet motors under heavy loads, and optimizes torque output capability and running stability across the entire speed range.
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Figure CN121813790B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of electric motors, and particularly relates to a positive salient pole enhanced hybrid permanent magnet motor with high reluctance torque utilization. Background Technology
[0002] Leakage flux controllable permanent magnet motors are a new type of permanent magnet motor. By adjusting the quadrature-axis current, the magnitude of the quadrature-axis magnetic flux can be changed, thereby altering the saturation level of the leakage flux bridge and achieving leakage flux characteristics of low leakage flux at low speeds and high leakage flux at high speeds. Compared to traditional permanent magnet motors, leakage flux controllable permanent magnet motors increase the inter-pole leakage flux of the permanent magnets at high speeds, objectively reducing the effective air gap flux of the direct axis, thus enabling a wide speed range. At low speeds, typically accompanied by high load output, leakage flux controllable permanent magnet motors increase the quadrature-axis current to saturate the magnetic bridge, thereby weakening the leakage flux and objectively increasing the effective air gap flux of the direct axis, ensuring the motor's torque output capability at low speeds. The main advantage of this motor is that it passively adjusts the leakage flux through armature current, avoiding complex mechanical structural designs and eliminating the need for additional excitation windings, resulting in high motor reliability.
[0003] In 2015, T. Kato, an expert at Nissan's Electric Vehicle Systems Laboratory in Japan, clarified the operating principle of this type of motor based on the concept of "variable leakage flux," theoretically analyzed the conditions for achieving "variable leakage flux," and designed a 54-slot, 6-pole permanent magnet motor with controllable leakage flux by reasonably setting the position of the leakage flux bridge and the magnitude of the permanent magnet magnetomotive force. Comparing this motor with traditional permanent magnet motors, he demonstrated that this type of motor has a significant advantage in iron loss distribution in the high-speed region. Zhu Xiaoyong's team at Jiangsu University conducted a series of studies on "controllable leakage flux," designing several permanent magnet motors with controllable leakage flux. Based on the inductance change characteristics caused by the quadrature-axis current of the controllable leakage flux permanent magnet motor, they proposed the concept of "variable salient pole," which can achieve anti-salient pole at low speeds by applying a positive direct-axis current to utilize positive reluctance torque, and achieve positive salient pole at high speeds. This effectively improves the torque output capability in the weak magnetic region and reduces the risk of irreversible demagnetization in traditional permanent magnet motors.
[0004] In all existing leakage flux controllable permanent magnet motors, the leakage flux and the main permanent magnet flux share the same flux loop. When the leakage flux bridge is saturated by the armature magnetic field, the main permanent magnet flux still needs to pass through the saturated leakage flux bridge to enter the air gap and stator windings. This leads to a decrease in the utilization rate of the permanent magnet and insufficient torque output capability at low speeds, which is a major reason limiting the application of this type of motor in practical electric vehicles. How to improve the torque output in the low-speed range of this type of leakage flux controllable motor has become one of the urgent problems to be solved. Summary of the Invention
[0005] The purpose of this invention is to at least partially solve the above-mentioned technical problems, and to provide a high reluctance torque utilization rate positive salient pole enhanced hybrid permanent magnet motor. This high reluctance torque utilization rate positive salient pole enhanced hybrid permanent magnet motor can improve the reluctance torque utilization rate under low-speed conditions and has a high salient pole ratio.
[0006] This invention provides a high reluctance torque utilization rate positive salient pole enhanced hybrid permanent magnet motor, comprising a stator structure and a hybrid pole rotor, wherein the stator structure is sleeved on the outer periphery of the hybrid pole rotor; the hybrid pole rotor includes a rotor core and m flux-adjustable rotor pole units and m inductance-adjustable rotor pole units alternately arranged on the rotor core, where m is an integer greater than 1; each flux-adjustable rotor pole unit includes a cross-axis magnetic barrier structure and two identical flux-adjustable poles symmetrically arranged on both sides of the cross-axis magnetic barrier structure; wherein the cross-axis magnetic barrier structure includes a first sector-shaped leakage magnetic barrier arranged radially from the inside to the outside and a discontinuous sector-shaped magnetic barrier composed of two second leakage magnetic barriers; the center of symmetry of the first sector-shaped leakage magnetic barrier and the discontinuous sector-shaped magnetic barrier is... The line coincides with the cross axis of the flux-adjusting rotor magnetic pole unit; the flux-adjusting magnetic pole includes a first permanent magnet and a third permanent magnet arranged in a V-shape with their openings facing the air gap. The angle bisector of the angle between the first permanent magnet and the third permanent magnet is the direct axis of the flux-adjusting rotor magnetic pole unit in which they are located. The first permanent magnet and the third permanent magnet have a first end magnetic barrier at one end away from the air gap, and the other end of the third permanent magnet has a second end magnetic barrier. The inductance-adjusting rotor magnetic pole unit includes two inductance-adjusting magnetic poles with identical structures symmetrically arranged on both sides of its cross axis. The inductance-adjusting magnetic pole includes t parallel magnetic pole layers. Each magnetic pole layer consists of a second permanent magnet and connecting magnetic barriers located at both ends of it. The radial centerline of the second permanent magnet is located on the direct axis of the inductance-adjusting rotor magnetic pole unit, and t is an integer greater than or equal to 1.
[0007] In some embodiments, the angle bisector of the cross axis of two adjacent flux-adjustable rotor pole units coincides with the cross axis of the inductance-adjustable rotor pole unit located between them.
[0008] In some embodiments, the quadrature axes of both the flux-adjustable rotor pole unit and the inductance-adjustable rotor pole unit are aligned with the stator winding at i d =0 control, the direction of the quadrature-axis magnetic field generated by the quadrature-axis current is consistent with that of the flux-adjustable rotor pole unit and the inductance-adjustable rotor pole unit. The direction of the direct axis is consistent with that of the direct axis magnetic field generated by only the direct axis current passing through the stator winding.
[0009] In some embodiments, all permanent magnets are cuboids, magnetized along the thickness direction, and the permanent magnets in each flux-adjusting pole or inductance-adjusting pole are magnetized in the same direction, while the permanent magnets in adjacent flux-adjusting poles or inductance-adjusting poles are magnetized in opposite directions.
[0010] In some embodiments, the angle between the first permanent magnet and the third permanent magnet in the flux-adjusting magnetic poles is α. pm Satisfying 120° < α pm <160°.
[0011] In some embodiments, in the inductance-adjustable magnetic poles, the core region between two adjacent magnetic pole layers forms a connecting magnetic bridge, and the radial width of each connecting magnetic bridge remains consistent.
[0012] In some embodiments, m=2.
[0013] In some embodiments, t=3.
[0014] In some embodiments, the stator structure includes n stator teeth, where n = 2km and k is an integer greater than 0.
[0015] In some embodiments, the mechanical angle between the quadrature axis of the flux-adjusting rotor pole unit and the direct axis of the adjacent inductance-adjusting rotor pole unit is α. b α b ±α a +135° / m; where α a α is the mechanical offset angle of the inductor-adjustable rotor pole unit. a ∈[-3°,3°].
[0016] The high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor according to embodiments of the present invention has at least one of the following advantages:
[0017] 1. This invention forms a hybrid magnetic pole motor rotor structure by setting up a flux-adjustable rotor magnetic pole unit with adjustable air gap characteristics and an inductance-adjustable rotor magnetic pole unit with high saliency ratio characteristics. Under low-speed, high-load conditions, the inductance-adjustable unit plays a core role: its three-layer magnetic barrier structure, combined with the magnetic bridge path, ensures that when the direct-axis current increases, the direct-axis magnetic flux flows through a high-resistivity circuit, and the direct-axis inductance decreases accordingly; while the quadrature-axis magnetic circuit has no permanent magnets or magnetic barriers, resulting in lower magnetic resistance and essentially unchanged quadrature-axis inductance, thus reducing the difference between the direct and quadrature-axis inductance (L). q -L dThe salient pole ratio (L) increases with increasing load. Simultaneously, the flux regulation unit ensures the main flux effectively participates in torque output. The two work synergistically to significantly improve the reluctance torque utilization rate at low speeds, overcoming the shortcomings of traditional leakage flux controllable permanent magnet motors under heavy loads, which suffer from reduced inductance difference and insufficient torque output due to quadrature axis magnetic circuit saturation. At high speeds, the flux regulation unit achieves wide-range speed regulation by adjusting the permanent magnet air gap flux, eliminating the need for negative direct axis demagnetizing current injection; the inductance regulation unit maintains the advantage of the quadrature and direct axis inductance difference, further optimizing torque output capability. These two components complement each other, jointly achieving efficient motor operation across the entire speed range and multiple operating conditions, significantly improving the saliency ratio (L) of traditional leakage flux controllable permanent magnet motors. q / L d ).
[0018] 2. The invention decouples the flux adjustment unit from the inductance adjustment unit by setting an independent inductance adjustment unit bypass, thereby avoiding the coupling between the main magnetic circuit of the inductance adjustment unit and the magnetic circuit of the flux adjustment unit. This solves the drawback of reduced utilization of permanent magnets caused by magnetic circuit coupling in traditional leakage flux controllable permanent magnet motors, and improves the motor torque output capability per unit volume.
[0019] 3. The magnetic flux adjustment unit and the inductance adjustment unit of this invention are independent of each other. By shifting the magnetic poles, the symmetrical distribution relationship of the two rotor units is changed, which can realize the adjustment of the magnetic permeability distribution of the motor rotor and the number of unit cycles, further improving the output torque characteristics of the motor, reducing the torque pulsation of the motor, and improving the running stability of this type of motor. Attached Figure Description
[0020] These and / or other aspects and advantages of the present invention will become apparent and readily understood from the following description of preferred embodiments taken in conjunction with the accompanying drawings, in which:
[0021] Figure 1 This is a schematic diagram of a high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor according to an embodiment of the present invention;
[0022] Figure 2 for Figure 1 The diagram shows the structure of the stator in a high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor.
[0023] Figure 3 for Figure 1 The diagram shows the structure of the hybrid pole rotor in a high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor.
[0024] Figure 4 for Figure 1 The diagram shows the magnetization direction of all permanent magnets in the flux-regulated rotor pole unit and the inductance-regulated rotor pole unit of the high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor.
[0025] Figure 5 for Figure 1 The diagram shows the no-load magnetic field distribution of a high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor.
[0026] Figure 6 for Figure 1 The diagram shows the magnetic field distribution of a high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor under rated load.
[0027] Figure 7 for Figure 1 The curves showing the variation of permanent magnet air gap flux as a function of quadrature axis current in a high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor are shown.
[0028] Figure 8 for Figure 1 The curves showing the torque versus current angle of a high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor under different currents are shown.
[0029] Figure 9 for Figure 1 The image shows the load torque waveforms before and after pole offset of a high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor.
[0030] Figure 10 for Figure 1 The diagram shows a prototype of a high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor.
[0031] Figure 11 for Figure 10 The diagram shows the back EMF waveform obtained from the prototype test and its THD comparison with the simulated waveform. Detailed Implementation
[0032] The technical solution of the present invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. In this specification, the same or similar reference numerals indicate the same or similar components. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the overall inventive concept of the present invention and should not be construed as a limitation thereof.
[0033] See Figure 1This paper illustrates the structure of a high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor according to an embodiment of the present invention. The hybrid permanent magnet motor includes a stator structure 1 and a hybrid pole rotor 2. The stator structure 1 is sleeved on the outer periphery of the hybrid pole rotor 2, and an air gap 3 is provided between the radially inner side of the stator structure 1 and the radially outer side of the hybrid pole rotor 2. The hybrid pole rotor 2 includes a rotor core and m flux-adjustable rotor pole units and m inductance-adjustable rotor pole units alternately arranged on the rotor core, where m is an integer greater than 1. The symmetry center line of two adjacent flux-adjustable rotor pole units coincides with the cross-axis of the inductance-adjustable rotor pole unit. The cross-axis directions of both the flux-adjustable rotor pole units and the inductance-adjustable rotor pole units are aligned with the stator winding at the i-th axis. d The quadrature-axis magnetic field generated by the quadrature-axis current flowing under =0 control is in the same direction; the direct axis directions of both the flux-adjustable rotor pole unit and the inductance-adjustable rotor pole unit are in the same direction as the direct axis magnetic field generated by only flowing a direct axis current through the stator winding. The direct axis direction of the inductance-adjustable rotor pole unit is obtained by rotating its quadrature-axis direction about the axis of rotation by a mechanical angle of 45° / m. For example, Figure 1 The high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor shown has two flux-regulated rotor pole units and two inductance-regulated rotor pole units. The direct axis direction of the inductance-regulated rotor pole unit is obtained by rotating its quadrature axis direction around the rotation axis by a mechanical angle of 22.5°.
[0034] Figure 2 for Figure 1 The diagram shows the stator structure of a high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor.
[0035] See Figure 2 The stator structure 1 includes stator teeth 1-2, stator yoke 1-1, and armature winding 1-3, wherein the armature winding 1-3 is wound on the stator teeth 1-2; the number of stator teeth 1-2 is n, where n is an integer multiple of 3 and greater than 0; the armature winding 1-3 adopts a double-layer distributed winding method.
[0036] Figure 3 for Figure 1 The diagram shows the structure of the hybrid pole rotor in a high reluctance torque utilization positive salient pole enhanced hybrid pole permanent magnet motor. The hybrid pole rotor 2 includes two rotor pole units: flux regulation and inductance regulation.
[0037] See Figure 3The flux-regulating rotor pole unit includes a cross-axis magnetic barrier structure and two identical flux-regulating poles symmetrically arranged on both sides of the cross-axis magnetic barrier structure. The cross-axis magnetic barrier structure includes a first sector-shaped leakage magnetic barrier 2-3 arranged radially from the inside out, and a discontinuous sector-shaped magnetic barrier formed by second leakage magnetic barriers 2-1 and 2-2. Magnetic bridge paths are provided between the second leakage magnetic barriers 2-1 and 2-2, between the second leakage magnetic barriers 2-1 and the air gap 3, between the second leakage magnetic barriers 2-2 and the air gap 3, and between the second leakage magnetic barriers 2-1, 2-2, and the first sector-shaped leakage magnetic barrier 2-3. The symmetrical center lines of the first sector-shaped leakage magnetic barrier 2-3 and the discontinuous sector-shaped magnetic barriers coincide with the cross-axis of the flux-regulating rotor pole unit; the bisector of the cross-axis angle of two adjacent flux-regulating rotor pole units coincides with the cross-axis of the inductor-regulating rotor pole unit located between the two flux-regulating rotor pole units.
[0038] See Figure 3 One flux-regulating pole in the flux-regulating rotor pole unit is designated as the first flux-regulating pole. The first flux-regulating pole includes a first permanent magnet 2-7 and a third permanent magnet 2-8 arranged in a V-shape with their openings facing the air gap. The angle bisector formed by the first permanent magnet 2-7 and the third permanent magnet 2-8 is the direct axis of the flux-regulating rotor pole unit in which they reside, and the included angle between the first permanent magnet 2-7 and the third permanent magnet 2-8 is α. pm Satisfying 120° < α pm <160°. The first permanent magnet 2-7 and the third permanent magnet 2-8 each have a first end magnetic barrier 2-9 at the end furthest from the air gap, and the other end of the third permanent magnet 2-8 has a second end magnetic barrier 2-6. The adjacent flux-adjusting magnetic pole is designated as the second flux-adjusting magnetic pole, with the first and third permanent magnets labeled 2-10 and 2-11 respectively.
[0039] See Figure 3 The inductor-adjustable rotor magnetic pole unit includes two structurally identical inductor-adjustable magnetic poles symmetrically arranged on both sides of its cross axis. Each inductor-adjustable magnetic pole includes three parallel magnetic pole layers. One of the inductor-adjustable magnetic poles is designated as the first inductor-adjustable magnetic pole. In the first inductor-adjustable magnetic pole, each magnetic pole layer consists of a second permanent magnet 2-4 and connecting magnetic barriers 2-5 located at both ends. The radial centerline of the second permanent magnet 2-4 is located on the direct axis of the inductor-adjustable rotor magnetic pole unit. The connecting magnetic barriers 2-5 are symmetrically distributed about the corresponding direct axis centerline of the second permanent magnet 2-4. The other adjacent inductor-adjustable magnetic pole is designated as the second inductor-adjustable magnetic pole. The second permanent magnets in each magnetic pole layer of the second inductor-adjustable magnetic pole are labeled as 2-12. In each inductor-adjustable magnetic pole, the core region between two adjacent magnetic pole layers forms a connecting magnetic bridge, and the radial width of each connecting magnetic bridge remains consistent.
[0040] See Figure 3 The angle between the quadrature axis of the flux-regulating rotor pole unit and the direct axis of the adjacent inductance-regulating rotor pole unit is defined as α. b When the rotor's magnetic poles are symmetrically distributed, α b= 135° / m; when the inductor-adjusted rotor magnetic pole unit mechanically deviates by ±α a When α is at an angle b ±α a +135° / m; α a The mechanical offset angle satisfies α a ∈[-3°,3°], selecting an appropriate mechanical offset angle can achieve the increase of torque output and the suppression of torque pulsation.
[0041] Figure 1 In the high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor shown, all permanent magnets are cuboids and magnetized along the thickness direction. The permanent magnets in each flux-adjustable pole or inductance-adjustable pole are magnetized in the same direction, while the permanent magnets in adjacent flux-adjustable poles or inductance-adjustable poles are magnetized in opposite directions.
[0042] For example, Figure 4 It shows Figure 1 The magnetization direction of all permanent magnets in the flux-regulated rotor pole unit and the inductance-regulated rotor pole unit of the high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor shown.
[0043] See Figure 4 In the first flux-adjusting magnetic pole, the magnetization direction of the first permanent magnet 2-7 is the same as that of the third permanent magnet 2-8. In the second flux-adjusting magnetic pole, the magnetization direction of the first permanent magnet 2-10 is the same as that of the third permanent magnet 2-11, but opposite to that of the first permanent magnet 2-7. The first inductance-adjusting magnetic pole is adjacent to the second flux-adjusting magnetic pole. In the first inductance-adjusting magnetic pole, the magnetization direction of the second permanent magnet 2-4 in each electromagnetic layer is the same, opposite to that of the second permanent magnet 2-12 in the second inductance-adjusting magnetic pole, and opposite to that of the third permanent magnet 2-11 in the second flux-adjusting magnetic pole.
[0044] In this invention, the magnetization direction is determined by whether it points towards the air gap. If the magnetization direction of both permanent magnets points towards the air gap, they are considered to have the same magnetization direction. If the magnetization direction of one permanent magnet points towards the air gap and the magnetization direction of the other permanent magnet points towards the inner ring of the rotor core (the side away from the air gap), they are considered to have opposite magnetization directions.
[0045] In some embodiments of the present invention, the number n of stator teeth 1-2 and the number m of flux-adjustable rotor pole units and inductance-adjustable rotor pole units satisfy: n=2km, k is an integer greater than 0.
[0046] By changing the magnitude of the armature current flowing through the armature winding 1-3, the leakage flux of the rotor pole unit can be adjusted online, thereby regulating the effective permanent magnet air gap flux of the motor. Specifically, when no current flows through the stator winding 1-3, most of the permanent magnet flux generated by the first permanent magnet 2-10 forms a closed loop through the magnetic bridge path without passing through the air gap. At this time, the effective magnetic flux of the motor comes from the second permanent magnet 2-4 in the inductance-adjusting pole and the third permanent magnet 2-11 adjacent to the inductance-adjusting pole. The effective permanent magnet air gap flux of the motor is relatively small, which is beneficial for reducing the back EMF at high speeds. When a rated current of 7A flows through the stator winding 1-3, most of the permanent magnet flux generated by the first permanent magnet 2-10 passes through the air gap to form effective flux. At this time, the effective magnetic flux of the motor comes from all permanent magnets. The effective air gap flux of the motor increases, which is beneficial for improving the output torque of the motor at low speeds.
[0047] By altering the saturation level of the connecting magnetic bridge in the inductance-adjustable rotor pole unit, the motor inductance can be adjusted. Furthermore, by changing the number of pole layers (t) in the inductance-adjustable rotor pole unit, the motor's direct and quadrature axis inductance parameters can be designed, thereby improving the reluctance torque utilization rate.
[0048] The electromagnetic field simulation software ANSYS Maxwell was used to simulate the embodiments of the present invention. Figure 1 A simulation was performed on the high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor shown. The stator outer diameter was set to 166mm, the stator inner diameter to 102mm, the air gap to 0.6mm, the motor shaft length to 60mm, n=48, m=2, and the armature winding (1-3) rated armature current to 7A. α pm =120°, α a =-1.8° result as follows Figure 5-9 As shown.
[0049] Figure 5 for Figure 1 The figure shows the simulated no-load flux distribution waveform of a high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor when no current is applied to the stator winding. Figure 5 As can be seen from this, most of the permanent magnet flux generated by the first permanent magnet near the cross-axis leakage magnetic structure passes through the magnetic bridge path to form a closed loop without passing through the air gap. At this time, the effective magnetic flux of the motor comes from other permanent magnets. The effective air gap magnetic flux of the permanent magnet of the motor is small, which is beneficial to reduce the back EMF under high-speed operation.
[0050] Figure 6 for Figure 1 The figure shows the simulated load flux distribution waveform of a high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor when a rated current of 7A is applied to the stator winding. Figure 6As can be seen from this, most of the permanent magnet flux generated by the first permanent magnet near the cross-axis leakage magnetic structure passes through the air gap to form effective flux. At this time, the effective flux of the motor comes from all the permanent magnets. The effective air gap flux of the motor increases, which is beneficial to improving the output torque of the motor at low speed.
[0051] Figure 7 This is a graph showing the change in permanent magnet air gap flux of a high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor as a function of armature current flowing through the stator winding. Figure 7 As can be seen, when the armature current flowing through the stator winding increases, the permanent magnet air gap flux linkage of the motor increases accordingly, verifying the variable flux characteristics of the motor's flux adjustment unit.
[0052] Figure 8 This is a graph showing the change of electromagnetic torque with current angle when different currents are applied to the stator winding in a high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor. Figure 8 As can be seen, when the current angle is 30 degrees, the torque value is the highest, and the reluctance torque is relatively large, about 3.1 Nm, accounting for 27.4% of the total torque. At this time, the reluctance torque utilization rate of the motor is relatively high.
[0053] Figure 9 A comparison of the output torque of a high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor before and after pole offset (mechanical offset angle α). a (for -1.8°) Figure 9 As can be seen, when the rotor poles are not offset, the motor's output torque is 10.99 Nm with a torque ripple of 9.24%. After the offset, the motor's output torque is 11.28 Nm with a torque ripple of 7.89%. It is evident that the motor's torque output is improved and the torque ripple is reduced after the offset.
[0054] Figure 10 This is a schematic diagram of a prototype of a high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor. Figure 11 for Figure 10 The back EMF waveform obtained from the prototype test and its THD comparison with the simulated waveform are shown in the figure. It can be seen that the simulation and test results are basically consistent, which verifies the effectiveness of the motor design.
[0055] The high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor according to embodiments of the present invention has at least one of the following advantages:
[0056] 1. This invention forms a hybrid magnetic pole motor rotor structure by setting up a flux-adjustable rotor magnetic pole unit with adjustable air gap characteristics and an inductance-adjustable rotor magnetic pole unit with high saliency ratio characteristics. Under low-speed, high-load conditions, the inductance-adjustable unit plays a core role: its three-layer magnetic barrier structure, combined with the magnetic bridge path, ensures that when the direct-axis current increases, the direct-axis magnetic flux flows through a high-resistivity circuit, and the direct-axis inductance decreases accordingly; while the quadrature-axis magnetic circuit has no permanent magnets or magnetic barriers, resulting in lower magnetic resistance and essentially unchanged quadrature-axis inductance, thus reducing the difference between the direct and quadrature-axis inductance (L). q -L d The salient pole ratio (L) increases with increasing load. Simultaneously, the flux regulation unit ensures the main flux effectively participates in torque output. The two work synergistically to significantly improve the reluctance torque utilization rate at low speeds, overcoming the shortcomings of traditional leakage flux controllable motors under heavy loads, such as decreased inductance difference and insufficient torque output due to quadrature axis magnetic circuit saturation. At high speeds, the flux regulation unit achieves wide-range speed regulation by adjusting the permanent magnet air gap flux, eliminating the need for negative direct axis demagnetizing current injection; the inductance regulation unit maintains the advantage of the quadrature and direct axis inductance difference, further optimizing torque output capability. These two components complement each other, jointly achieving efficient motor operation across the entire speed range and multiple operating conditions, significantly improving the saliency ratio (L) of traditional leakage flux controllable permanent magnet motors. q / L d ).
[0057] 2. By setting an independent inductor adjustment unit bypass, the present invention decouples the flux adjustment unit from the inductor adjustment unit, avoids the coupling between the main magnetic circuit of the inductor adjustment unit and the magnetic circuit of the flux adjustment unit, solves the drawback of the reduced utilization rate of permanent magnets caused by the magnetic circuit coupling of traditional leakage flux controllable permanent magnet motors, and improves the motor torque output capability per unit volume.
[0058] 3. The magnetic flux adjustment unit and the inductance adjustment unit of this invention are independent of each other. By shifting the magnetic poles, the symmetrical distribution relationship of the two rotor units is changed, which can realize the adjustment of the magnetic permeability distribution of the motor rotor and the number of unit cycles, further improving the output torque characteristics of the motor, reducing the torque pulsation of the motor, and improving the running stability of this type of motor.
[0059] While some embodiments of the present general inventive concept have been shown and described, those skilled in the art will understand that changes may be made to these embodiments without departing from the principles and spirit of the present general inventive concept, the scope of which is defined by the claims and their equivalents.
Claims
1. A high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor, comprising a stator structure and a hybrid pole rotor, wherein the stator structure is sleeved on the outer periphery of the hybrid pole rotor; the hybrid pole rotor comprises a rotor core and m flux-adjustable rotor pole units and m inductance-adjustable rotor pole units alternately arranged on the rotor core, wherein m is an integer greater than 1; The flux-adjusting rotor pole unit includes a quadrature-axis magnetic barrier structure and two identical flux-adjusting magnetic poles symmetrically arranged on both sides of the quadrature-axis magnetic barrier structure; wherein... The cross-axis magnetic barrier structure includes a first sector-shaped leakage magnetic barrier and a discontinuous sector-shaped magnetic barrier composed of two second leakage magnetic barriers arranged radially from the inside to the outside; the symmetrical center lines of the first sector-shaped leakage magnetic barrier and the discontinuous sector-shaped magnetic barrier coincide with the cross-axis of the magnetic flux regulating rotor magnetic pole unit; the magnetic flux regulating magnetic pole includes a first permanent magnet and a third permanent magnet arranged in a V-shape with their openings facing the air gap, the angle bisector of the angle between the first permanent magnet and the third permanent magnet is the direct axis of the magnetic flux regulating rotor magnetic pole unit in which they are located, a first end magnetic barrier is provided at one end of the first permanent magnet and the third permanent magnet away from the air gap, and a second end magnetic barrier is provided at the other end of the third permanent magnet; The inductance-adjustable rotor magnetic pole unit includes two identical inductance-adjustable magnetic poles symmetrically arranged on both sides of its cross axis; the inductance-adjustable magnetic pole includes t parallel magnetic pole layers, each magnetic pole layer consisting of a second permanent magnet and connecting magnetic barriers located at its two ends, the radial centerline of the second permanent magnet being located on the direct axis of the inductance-adjustable rotor magnetic pole unit, and t being an integer greater than or equal to 1.
2. The high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor according to claim 1, characterized in that, The angle bisector of the intersection axis of two adjacent flux-adjustable rotor pole units coincides with the intersection axis of the inductance-adjustable rotor pole unit located between them.
3. The high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor according to claim 1, characterized in that, The cross-axis directions of both the flux-adjustable rotor pole unit and the inductance-adjustable rotor pole unit are at the same point as the stator winding. d The quadrature-axis magnetic field generated by the quadrature-axis current flowing under =0 control is in the same direction; The direct axis direction of both the flux-adjustable rotor pole unit and the inductance-adjustable rotor pole unit is consistent with the direction of the direct axis magnetic field generated by only passing a direct axis current through the stator winding.
4. The high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor according to claim 1, characterized in that, All permanent magnets are cuboids, magnetized along their thickness. The permanent magnets in each flux-adjustable or inductance-adjustable pole are magnetized in the same direction, while the permanent magnets in adjacent flux-adjustable or inductance-adjustable poles are magnetized in opposite directions.
5. The high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor according to claim 1, characterized in that, The angle between the first permanent magnet and the third permanent magnet in the flux-adjusting magnetic pole is α. pm Satisfying 120° < α pm <160°.
6. The high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor according to claim 1, characterized in that, In the inductor-adjustable magnetic pole, the iron core region between two adjacent magnetic pole layers forms a connecting magnetic bridge, and the radial width of each connecting magnetic bridge remains consistent.
7. The high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor according to claim 1, characterized in that, m=2。 8. The high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor according to claim 1, characterized in that, t=3。 9. The high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor according to claim 1, characterized in that, The stator structure includes n stator teeth, where n = 2km and k is an integer greater than 0.
10. The high reluctance torque utilization positive salient pole enhanced hybrid permanent magnet motor according to claim 1, characterized in that, The mechanical angle between the quadrature axis of the flux-adjusting rotor pole unit and the direct axis of the adjacent inductance-adjusting rotor pole unit is α. b α b ±α a +135° / m; where α a α is the mechanical offset angle of the inductor-adjustable rotor pole unit. a ∈[-3°,3°].