Motor rotor and self-starting synchronous reluctance motor

Abstract

The application provides a motor rotor and a self-starting synchronous reluctance motor. The motor rotor comprises a rotor core (1), the rotor core (1) is provided with filling grooves, slot grooves (2) and air grooves (8), the filling grooves comprise independent filling grooves (4) and non-independent filling grooves (3), the non-independent filling grooves (3) are arranged on both sides of the slot grooves (2), the air grooves (8) are arranged on the side of the filling grooves away from the q axis and between the filling grooves and the outer circle of the rotor, and the air grooves (8) are arranged in the same layer as the filling grooves corresponding to the air grooves (8). According to the motor rotor, the aluminum consumption caused by the harmonics of the self-starting synchronous reluctance motor can be reduced, and the efficiency of the motor is further improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric machines, in particular to an electric machine rotor and a self-starting synchronous reluctance machine. BACKGROUND

[0002] The self-starting synchronous reluctance machine combines the advantages of the asynchronous machine on the basis of the synchronous reluctance machine, and realizes self-starting through the asynchronous torque generated by the rotor bar, without the need to use a frequency converter for driving. Compared with the asynchronous machine, the electric machine can realize constant-speed operation, the rotor loss is low, and the efficiency is improved during synchronous operation; compared with the asynchronous-starting permanent-magnet synchronous machine, the electric machine does not use permanent-magnet materials, has low cost, and does not have the problem of permanent-magnet demagnetization. However, due to the multi-layer magnetic barrier layer structure of the self-starting synchronous reluctance machine, the electric machine has the problem of large aluminum consumption. SUMMARY

[0003] Therefore, the technical problem to be solved by the present application is to provide an electric machine rotor and a self-starting synchronous reluctance machine, which can reduce the aluminum consumption caused by harmonics of the self-starting synchronous reluctance machine, and further improve the efficiency of the electric machine.

[0004] In order to solve the above problems, the present application provides an electric machine rotor, which comprises a rotor core, and the rotor core is provided with filling grooves, slit grooves and air grooves. The filling grooves comprise independent filling grooves and non-independent filling grooves, the non-independent filling grooves are arranged on both sides of the slit grooves, the air grooves are arranged on the side of the filling grooves away from the q-axis and between the filling grooves and the outer circle of the rotor, and the air grooves and the filling grooves corresponding to the air grooves are arranged in the same layer.

[0005] Preferably, the minimum distance between the inner wall of the air groove close to the outer circle of the rotor and the inner wall close to the filling groove in the same layer is L, and L≥20*σ / q, wherein σ is the width of the air gap between the stator and the rotor, and q is the number of slots per pole per phase of the stator of the electric machine.

[0006] Preferably, the width h of the air groove in the q-axis direction satisfies 0.8h1≤h≤1.4h1, and h1 is the width of the filling groove in the same layer and closest to the air groove in the q-axis direction.

[0007] Preferably, a magnetic isolation bridge is formed between the air groove and the filling groove in the same layer and closest to the air groove, the width of the magnetic isolation bridge is L1, and 0.5σ≤L1≤2σ, wherein σ is the width of the air gap between the stator and the rotor.

[0008] Preferably, the total area of the filling grooves accounts for 30% to 70% of the sum of the areas of the filling grooves, the air grooves and the slit grooves.

[0009] Preferably, the total area of the filling grooves accounts for 35% to 50% of the sum of the areas of the filling grooves, the air grooves and the slit grooves.

[0010] Preferably, air slots are arranged between the independent filling slots and the outer circle of the rotor, and the included angle between the outer edge of the air slots at both ends of the independent filling slots and the center line of the rotor core in the cross section perpendicular to the central axis of the rotor core is a1, 20°≤a1≤60°.

[0011] Preferably, the width of the non-independent filling slot along the q-axis direction is h1, the maximum width of the slot gap along the q-axis direction arranged in the same layer as the non-independent filling slot is h2, and 0.8h2≤h1≤1.4h2.

[0012] Preferably, 0.9h2≤h1≤1.1h2.

[0013] Preferably, the minimum width of the magnetic flux channel between the two adjacent non-independent filling slots is d1, and the minimum width of the magnetic flux channel between the two slot gaps corresponding to the two non-independent filling slots is d2, d1≥d2.

[0014] Preferably, the slot gap includes an arc segment and / or a straight line segment, when the slot gap includes an arc segment, the arc of the arc segment gradually increases along the direction from the rotor shaft hole to the outer circle of the rotor, and the outer circle arc of the slot gap in the same layer is greater than the inner circle arc.

[0015] Preferably, the slot gap includes an arc segment or a straight line segment, and the width of the slot gap in the q-axis direction increases along the direction from both sides of the q-axis; and / or, the slot gap includes an arc segment and a straight line segment, the straight line segment is arranged at both ends of the arc segment, and the width of the arc segment in the q-axis direction increases along the direction from both sides of the q-axis.

[0016] Preferably, the width of the q-axis independent filling slot along the q-axis direction is m1, the width of the slot gap along the q-axis direction is m2, and the width of the rotor core from the rotor shaft hole to the outer circle of the rotor is m3, (m1+∑m2) / m3=0.3-0.5.

[0017] Preferably, under the same pole, the non-independent filling slot, the air slot and the slot gap in the same layer form a magnetic barrier layer, the air slot and the q-axis independent filling slot in the same layer form a magnetic barrier layer, each magnetic barrier layer is arranged symmetrically about the q-axis, and the magnetic barrier layers are arranged in at least two layers along the radial direction.

[0018] Preferably, the non-independent filling slot and the slot gap in each magnetic barrier layer are separated by a magnetic isolation bridge, and the width L2 of the magnetic isolation bridge satisfies 0.6σ≤L2≤2σ, where σ is the width of the air gap between the stator and the rotor.

[0019] Preferably, 0.8σ≤L2≤1.2σ.

[0020] Preferably, the minimum distance between adjacent magnetic barrier layers is L4, the minimum width of the magnetic barrier layer with smaller width in the q-axis direction in the adjacent magnetic barrier layers is L3, and L4≥1.5L3.

[0021] Preferably, the minimum distance between the magnetic barrier layer and the outer circle of the rotor is L5, 0≤L5≤2.5σ, and σ is the width of the air gap between the stator and the rotor.

[0022] Preferably, the filling slots are at least partially filled with a conductive and non-magnetic material, and the short circuit is achieved by end rings at both ends of the rotor core to form a squirrel cage.

[0023] Preferably, the rotor shaft hole of the rotor core is circular, elliptical or polygonal.

[0024] According to another aspect of the present application, a self-starting synchronous reluctance motor is provided, comprising a motor rotor as described above.

[0025] The motor rotor provided by the present application comprises a rotor core, and filling slots, slit slots and air slots are formed in the rotor core. The filling slots comprise independent filling slots and non-independent filling slots, the non-independent filling slots are arranged on both sides of the slit slots, the air slots are arranged on the side of the filling slots away from the q-axis and between the filling slots and the outer circle of the rotor, and the air slots are arranged in the same layer as the filling slots corresponding to the air slots. On the basis of the rotor magnetic barrier layer composed of the non-independent filling slots and the slit slots or the rotor magnetic barrier layer composed of the independent filling slots, the air slots are arranged, the relative positions between the air slots and the filling slots are adjusted to ensure the flow of magnetic flux between the magnetic barrier layers and reduce the leakage magnetic flux between the air slots and the filling slots. At the same time, the loss of magnetic lines of force when entering the stator from the rotor is reduced, the aluminum consumption caused by harmonics is reduced, and the efficiency of the motor is improved. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 A structural schematic diagram of a motor rotor of an embodiment of the present application;

[0027] Figure 2 A structural schematic diagram of a motor rotor of an embodiment of the present application;

[0028] Figure 3 A comparison diagram of harmonic loss of a motor of an embodiment of the present application and a motor of related art;

[0029] Figure 4 A comparison diagram of efficiency of a motor of an embodiment of the present application and a motor of related art.

[0030] The reference signs are as follows:

[0031] 1, rotor core; 2, slit slot; 3, non-independent filling slot; 4, independent filling slot; 5, magnetic isolation bridge; 6, rotor shaft hole; 7, magnetic flux channel; 8, air slot. DETAILED DESCRIPTION

[0032] For reference Figures 1 to 4As shown, according to the embodiment of the present application, the motor rotor comprises a rotor core 1, the rotor core 1 is provided with filling slots, slotting slots 2 and air slots 8, the filling slots comprise independent filling slots 4 and non-independent filling slots 3, the non-independent filling slots 3 are arranged on both sides of the slotting slots 2, the air slots 8 are arranged on the side of the filling slots away from the q-axis and between the filling slots and the outer circle of the rotor, and the air slots 8 and the filling slots corresponding to the air slots 8 are arranged in the same layer.

[0033] The motor rotor sets the air slots 8 on the basis of the rotor magnetic barrier layer composed of the non-independent filling slots 3 and the slotting slots 2 or the rotor magnetic barrier layer composed of the independent filling slots 4, adjusts the relative position between the air slots 8 and the filling slots, ensures the magnetic flux flow between the magnetic barrier layers, reduces the magnetic leakage between the air slots 8 and the filling slots, reduces the loss of the magnetic lines of force from the rotor into the stator, reduces the aluminum consumption caused by the harmonics, and improves the motor efficiency.

[0034] The air slots 8 are located on the side of the filling slots close to the outer circle of the rotor and are arranged in the same layer as the filling slots along the outer circle of the rotor core 1. This arrangement makes the filling slots away from the air gap formed between the stator and the rotor, reduces the influence of the air gap magnetic field harmonics on the filling slots, thereby reducing the aluminum consumption and improving the motor efficiency.

[0035] In the embodiment, the independent filling slots 4 are the filling slots not in the same layer as the slotting slots 2, and the non-independent filling slots 3 are the filling slots in the same layer as the slotting slots 2.

[0036] In one embodiment, the independent filling slots 4 in the same layer can be arranged in multiple blocks or in a whole block.

[0037] In one embodiment, the minimum distance between the inner wall of the air slot 8 close to the outer circle of the rotor and the inner wall close to the filling slot in the same layer is L, and L≥20*σ / q, where σ is the width of the air gap between the stator and the rotor, and q is the number of slots per phase per pole of the motor stator. The purpose of this arrangement is to reduce the loss of the magnetic lines of force from the rotor into the stator, reduce the aluminum consumption caused by the harmonics, and improve the motor efficiency.

[0038] In one embodiment, the width h of the air slot 8 in the q-axis direction satisfies 0.8h1≤h≤1.4h1, and h1 is the width of the filling slot in the same layer and closest to the air slot 8 in the q-axis direction. This arrangement is to ensure that there is a suitable width between adjacent air slots 8 to avoid magnetic field saturation, affect the magnetic flux flow between the magnetic barrier layers, cause the motor output to decrease and the motor efficiency to decrease.

[0039] In one embodiment, the air slot 8 and the filling slot form a magnetic isolation bridge 5, the width of the magnetic isolation bridge 5 is L1, 0.5σ≤L1≤2σ, where σ is the width of the air gap between the stator and the rotor. By limiting the width of the magnetic isolation bridge 5 to be L1 and the width of the air gap between the stator and the rotor, the purpose is to ensure the mechanical strength of the rotor structure, reduce the magnetic leakage between the air slot 8 and the filling slot, and improve the efficiency of the motor.

[0040] In one embodiment, the total area of the filling slot accounts for 30% to 70% of the sum of the areas of the filling slot, the air slot 8 and the slit slot 2.

[0041] Preferably, the total area of the filling slot accounts for 35% to 50% of the sum of the areas of the filling slot, the air slot 8 and the slit slot 2, so as to ensure a certain proportion of the filling slot area, so that the motor can have a certain load starting capability.

[0042] In one embodiment, the air slot 8 is arranged between the independent filling slot 4 and the outer circle of the rotor, and in the cross section perpendicular to the central axis of the rotor core 1, the included angle between the outer edge of the air slot 8 at both ends of the independent filling slot 4 and the center line of the rotor core 1 is α1, 20°≤α1≤60°. In this way, the combined structure formed by the independent filling slot 4 and the air slot 8 can not only be used as a magnetic barrier layer to increase the reluctance torque of the motor, but also be used as a starting squirrel cage to improve the starting performance of the motor.

[0043] In one embodiment, the width of the non-independent filling slot 3 along the q-axis direction is h1, the maximum width of the slit slot 2 arranged in the same layer as the non-independent filling slot 3 along the q-axis direction is h2, and 0.8h2≤h1≤1.4h2. Preferably, 0.9h2≤h1≤1.2h2. In this way, the magnetic conduction channel 7 between the slit slots 2 will not be overloaded, which will reduce the output of the motor and the efficiency of the motor, thereby effectively ensuring the working performance of the motor.

[0044] In one embodiment, the minimum width of the magnetic conduction channel 7 between the two adjacent non-independent filling slots 3 is d1, and the minimum width of the magnetic conduction channel 7 between the two slit slots 2 corresponding to the two non-independent filling slots 3 is d2, d1≥d2. The purpose of this limitation is to ensure that there is enough width between the filling slots to avoid magnetic field saturation and affect the magnetic flux flow between the magnetic barrier layers.

[0045] In one embodiment, the slit slot 2 includes an arc segment or a straight line segment, when the slit slot 2 includes an arc segment, the arc of the arc segment gradually increases along the direction from the rotor shaft hole 6 to the outer circle of the rotor, and the outer circle arc of the slit slot 2 in the same layer is larger than the inner circle arc.

[0046] In one embodiment, the slit groove 2 of the same layer comprises an arc segment or a straight line segment, and the width of the slit groove 2 in the q-axis direction increases along the direction from the q-axis to both sides.

[0047] In one embodiment, the slit groove 2 of the same layer comprises an arc segment and a straight line segment, and the straight line segment is arranged at both ends of the arc segment, and the width of the arc segment in the q-axis direction increases along the direction from the q-axis to both sides. The straight line segment located on both sides of the arc segment is arranged parallel to the d-axis, and the straight line segment can be constant width, or the width of the straight line segment increases along the direction away from the shaft hole, or part of the width of the straight line segment increases along the direction away from the shaft hole and part of the width of the straight line segment is constant.

[0048] The above structure can increase the utilization rate of the rotor space, reasonably arrange the slit groove 2, increase the rotor saliency ratio, and improve the motor reluctance torque.

[0049] In one embodiment, the width of the independent filling groove 4 along the q-axis direction is m1, the width of the slit groove 2 along the q-axis direction is m2, and the width of the rotor core 1 from the rotor shaft hole 6 to the rotor outer circle is m3,

[0050] (m1+∑m2) / m3=0.3~0.5, so as to select a reasonable magnetic barrier ratio, ensure sufficient magnetic barrier width, and ensure reasonable magnetic flux channel, increase the saliency ratio of the motor, and prevent the magnetic circuit from being oversaturated.

[0051] In one embodiment, under the same pole, the non-independent filling groove 3, the air groove 8 and the slit groove 2 of the same layer form a layer of magnetic barrier layer, the air groove 8 and the independent filling groove 4 of the same layer form a layer of magnetic barrier layer, and each layer of magnetic barrier layer is symmetrically arranged about the q-axis. The magnetic barrier layer is arranged in at least two layers along the radial direction.

[0052] In one embodiment, the non-independent filling groove 3 and the slit groove 2 in each layer of magnetic barrier layer are separated by the magnetic isolation bridge 5, and the width L2 of the magnetic isolation bridge 5 satisfies 0.6σ≤L2≤2σ, and σ is the width of the air gap between the stator and the rotor. Preferably, 0.8σ≤L2≤1.2σ. Such arrangement can ensure the mechanical strength of the rotor structure and reduce the magnetic leakage between the filling groove and the slit groove 2.

[0053] In one embodiment, the minimum distance between adjacent magnetic barrier layers is L4, and the minimum width of the magnetic barrier layer with smaller width in the q-axis direction of the adjacent magnetic barrier layer is L3, and L4≥1.5L3. Such arrangement can reduce the difficulty of rotor processing and ensure the uniformity and unsaturation of the rotor flux density distribution.

[0054] In one embodiment, the minimum distance between the magnetic barrier layer and the outer circle of the rotor is L5, 0≤L5≤2.5σ, and σ is the width of the air gap between the stator and the rotor. By limiting the minimum distance L5 between the magnetic barrier layer and the outer circle of the rotor, the motor leakage can be reduced and the motor efficiency can be improved under the condition of ensuring the mechanical strength of the rotor.

[0055] In one embodiment, the slots are at least partially filled with electrically conductive and magnetically non-conductive material, and the short circuit is achieved through the end rings at both ends of the rotor core 1 to form a squirrel cage. In this embodiment, the slots of the independent filled slots 4 and the non-independent filled slots 3 are both filled with electrically conductive and magnetically non-conductive material, preferably aluminum or aluminum alloy, and the filled slots are self-short-circuited through the end rings at both ends of the rotor to form a squirrel cage structure. The end ring material is the same as the filled material in the filled slots. The self-short-circuited squirrel cage structure provides asynchronous torque during the starting stage of the motor to achieve self-starting of the motor; and the multi-layer magnetic barrier layer structure provides reluctance torque for the motor to achieve synchronous operation of the motor.

[0056] In one embodiment, the rotor shaft hole 6 of the rotor core 1 is circular, elliptical or polygonal. Preferably, the rotor shaft hole 6 of the rotor core 1 is elliptical, and the long axis of the elliptical shape coincides with the d-axis and the short axis coincides with the q-axis, so as to release more rotor space and enable the motor rotor to form stronger starting performance.

[0057] For reference Figure 3 and 4 As shown in Figs. 1 to 5, by comparing the aluminum consumption and the motor efficiency of the motor of the embodiment of the present application with those of the related art, it can be found that the motor of the embodiment of the present application can effectively reduce the aluminum consumption caused by the harmonics of the self-starting synchronous reluctance motor and improve the motor efficiency.

[0058] According to the embodiment of the present application, the self-starting synchronous reluctance motor comprises the motor rotor as described above.

[0059] It is easy for those skilled in the art to understand that the above-mentioned advantageous modes can be freely combined and superimposed without conflict.

[0060] The above is only a preferred embodiment of the present application, and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application. The above is only a preferred embodiment of the present application, and it should be pointed out that those skilled in the art can make several improvements and modifications without departing from the technical principles of the present application, and these improvements and modifications shall be regarded as the protection scope of the present application.

Claims

1. A motor rotor, characterized in that: The invention comprises a rotor core (1), wherein the rotor core (1) is provided with a filling slot, a slit slot (2) and an air slot (8), wherein the filling slot comprises an independent filling slot (4) and a non-independent filling slot (3), wherein the non-independent filling slot (3) is arranged on both sides of the slit slot (2), and the air slot (8) is arranged on a side of the filling slot away from the q-axis and located between the filling slot and the outer circle of the rotor, and the air slot (8) is arranged on the same layer as the filling slot corresponding to the air slot (8).

2. The motor rotor according to claim 1, characterized in that: The minimum distance between the inner wall of the air slot (8) close to the outer circle of the rotor and the inner wall close to the filling slot on the same layer is L, L≥20*σ / q, where σ is the width of the air gap between the stator and the rotor, and q is the number of slots per pole and per phase of the motor stator.

3. The motor rotor according to claim 1, characterized in that: The width h of the air slot (8) along the q-axis direction satisfies 0.8h1≤h≤1.4h1, where h1 is the width of the filling slot in the same layer as the air slot (8) and closest to it along the q-axis direction.

4. The motor rotor according to claim 1, characterized in that: A magnetic isolation bridge (5) is formed between the air slot (8) and the filling slot at the same layer and closest to the air slot (8), and the width of the magnetic isolation bridge (5) is L1, 0.5σ≤L1≤2σ, where σ is the width of the air gap between the stator and the rotor.

5. The motor rotor according to claim 1, characterized in that: The total area of ​​the filling slot accounts for 30% to 70% of the total area of ​​the filling slot, the air slot (8) and the slit slot (2).

6. The motor rotor according to claim 5, characterized in that: The total area of ​​the filling slot accounts for 35% to 50% of the total area of ​​the filling slot, the air slot (8) and the slit slot (2).

7. The motor rotor according to claim 1, characterized in that: The air slot (8) is arranged between the independent filling slot (4) and the outer circle of the rotor. In a cross section perpendicular to the central axis of the rotor core (1), the angle between the outer edges of the air slot (8) at both ends of the independent filling slot (4) and the center line of the rotor core (1) is α1, and 20°≤α1≤60°.

8. The motor rotor according to claim 1, characterized in that: The width of the non-independent filling groove (3) along the q-axis direction is h1, and the maximum width of the slit groove (2) arranged in the same layer as the non-independent filling groove (3) along the q-axis direction is h2, and 0.8h2≤h1≤1.4h2.

9. The motor rotor according to claim 8, characterized in that: 0.9h2≤h1≤1.1h2.

10. The motor rotor according to claim 1, characterized in that: The minimum width of the magnetic conductive channel (7) between two adjacent non-independent filling slots (3) is d1, and the minimum width of the magnetic conductive channel (7) between two slit slots (2) corresponding to the two non-independent filling slots (3) is d2, and d1≥d2.

11. The motor rotor according to claim 1, characterized in that: The slit slot (2) includes an arc segment and / or a straight line segment. When the slit slot (2) includes an arc segment, the curvature of the arc segment gradually increases along the direction from the rotor shaft hole (6) to the outer circle of the rotor, and the outer circle curvature of the slit slot (2) on the same layer is greater than the inner circle curvature.

12. The motor rotor according to claim 1, characterized in that: The slit groove (2) comprises an arc segment or a straight line segment, and the width of the slit groove (2) in the q-axis direction increases along the direction from the q-axis to both sides; and / or the slit groove (2) comprises an arc segment and a straight line segment, and the straight line segments are arranged at both ends of the arc segment, and the width of the arc segment in the q-axis direction increases along the direction from the q-axis to both sides.

13. The motor rotor according to claim 1, characterized in that The width of the q-axis independent filling slot (4) along the q-axis direction is m1, the width of the slit slot (2) along the q-axis direction is m2, the width of the rotor core (1) from the rotor shaft hole (6) to the rotor outer circle is m3, (m1+∑m2) / m3=0.3~0.

5.

14. The motor rotor according to claim 1, characterized in that Under the same pole, the non-independent filling slots (3), the air slots (8) and the slit slots (2) in the same layer form a magnetic barrier layer, and the air slots (8) and the q-axis independent filling slots (4) in the same layer form a magnetic barrier layer. The magnetic barrier layers are arranged symmetrically about the q-axis, and at least two layers of the magnetic barrier layers are arranged radially.

15. The motor rotor according to claim 14, characterized in that: The non-independent filling slots (3) and the slit slots (2) in each magnetic barrier layer are separated by a magnetic isolation bridge (5), and the width L2 of the magnetic isolation bridge (5) satisfies 0.6σ≤L2≤2σ, where σ is the width of the air gap between the stator and the rotor.

16. The motor rotor according to claim 15, characterized in that: 0.8σ≤L2≤1.2σ.

17. The motor rotor according to claim 14, characterized in that: The minimum distance between adjacent magnetic barrier layers is L4, and the minimum width of the magnetic barrier layer with a smaller width among the adjacent magnetic barrier layers in the q-axis direction is L3, where L4≥1.5L3.

18. The motor rotor according to claim 14, characterized in that: The minimum distance between the magnetic barrier layer and the outer circle of the rotor is L5, 0≤L5≤2.5σ, and σ is the width of the air gap between the stator and the rotor.

19. The motor rotor according to claim 1, characterized in that: At least part of the filling slots is filled with conductive but non-magnetic material, and short circuit is achieved through end rings at both ends of the rotor core (1) to form a squirrel cage.

20. The motor rotor according to claim 1, characterized in that The rotor shaft hole (6) of the rotor core (1) is circular, elliptical or polygonal.

21. A self-starting synchronous reluctance motor, comprising a motor rotor, characterized in that: The motor rotor is the motor rotor according to any one of claims 1 to 20.

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