A synchronous reluctance motor rotor structure and synchronous reluctance motor

Abstract

The present invention discloses a synchronous reluctance motor rotor structure and a synchronous reluctance motor. The rotor structure includes a rotating shaft and a rotor core mounted on the rotating shaft. The rotor core is provided with a plurality of circumferentially distributed air magnetic barrier groups, which protrude radially inward from the rotor core. Each air magnetic barrier group includes a plurality of air magnetic barrier layers arranged along the q-axis, with a magnetic conductive layer formed between adjacent air magnetic barrier layers. The cross-section of each air magnetic barrier layer along the rotor radial direction is considered to be enclosed by two long boundary lines and two short boundary lines, the two long boundary lines being the inner and outer long boundary lines, and both satisfying a circular curve parametric equation. The two endpoints of the long boundary line of the air magnetic barrier layer and the two short boundary lines also satisfy other parametric equations. In the same air magnetic barrier group, the long boundary lines of different magnetic barrier layers have different centers, forming an eccentric circular magnetic barrier. The eccentric circular magnetic barrier combined with the asymmetric design helps to improve the output torque of the synchronous reluctance motor and reduce torque pulsation.

Description

Technical Field

[0001] The present invention belongs to the technical field of synchronous reluctance motors, and in particular relates to a synchronous reluctance motor rotor structure and a synchronous reluctance motor. Background Art

[0002] Amid calls for energy conservation and emission reduction, synchronous reluctance motors (SRMs) have garnered widespread attention due to their simple structure, wide speed range, and low cost. Compared to permanent magnet synchronous motors, SRMs lack permanent magnets, eliminating the risk of demagnetization at high temperatures. Compared to induction motors, SRMs eliminate the need for rotor cage bars and field windings, reducing rotor losses and manufacturing costs. However, SRMs also have drawbacks, such as high torque ripple and low output torque, which have hindered their widespread application.

[0003] Synchronous reluctance motors (SRMs) generate reluctance torque based on the principle of minimum reluctance. The magnitude of this reluctance torque is related to the d- and q-axis inductances. A larger difference between the d- and q-axis inductances increases the SRM's reluctance torque; a smaller difference between the d- and q-axis inductances decreases the SRM's reluctance torque. The shape of the SRM's magnetic barrier affects the difference between the d- and q-axis inductances. To improve this difference, the SRM's magnetic barrier shape must be optimized.

[0004] The large torque pulsation of the synchronous reluctance motor is mainly related to the existence of spatial harmonics in the synchronous reluctance motor, and the spatial harmonics are mainly caused by unreasonable design of the stator and rotor geometric structures and stator current distortion. Generally, the stator structure and winding distribution of the synchronous reluctance motor are the same as those of the three-phase asynchronous motor with the same capacity. Therefore, the large torque pulsation of the synchronous reluctance motor is mainly due to unreasonable design of the rotor geometric structure.

[0005] Currently, the problems of large torque pulsation and low output torque of synchronous reluctance motors are mainly solved by optimizing the rotor structure. To this end, the present application proposes a synchronous reluctance motor rotor structure and a synchronous reluctance motor. Summary of the Invention

[0006] In view of the deficiencies in the prior art, the present invention aims to solve the technical problem of providing a synchronous reluctance motor rotor structure and a synchronous reluctance motor.

[0007] The technical solutions adopted by the present invention to solve the technical problems are as follows:

[0008] A synchronous reluctance motor rotor structure comprises a rotating shaft and a rotor core mounted on the rotating shaft; a plurality of circumferentially distributed air magnetic barrier groups are provided on the rotor core, the air magnetic barrier groups protrude radially inwardly of the rotor core, each air magnetic barrier group comprises a plurality of air magnetic barrier layers arranged along the q-axis, and a magnetic conductive layer is formed between adjacent air magnetic barrier layers; the structure is characterized in that a cross section of each air magnetic barrier layer along the radial direction of the rotor is considered to be enclosed by two long boundary lines and two short boundary lines, the two long boundary lines being inner and outer long boundary lines, respectively, and both satisfying the circular curve parameter equations of equations (1) to (6);

[0009]

[0010]

[0011] P B P D 2 +O′P D 2 =r′ 2 (3)

[0012] P A P D +O′P D =r′ (4)

[0013]

[0014]

[0015] Among them, P A is the intersection of the line connecting the centers O and O′ and the circle with O′ as the center, P B 、P C is the intersection of the circles centered at O ​​and O′, P D P B With P C The midpoint of the connecting line, r is the radius of the circle with O as the center, and r' is the radius of the circle with O' as the center;

[0016] The two endpoints P of the long boundary line of the air magnetic barrier layer B 、P C And any point of the two short boundary lines satisfies the parametric equation of formula (7);

[0017]

[0018] Where (x, y) is the position coordinate of the point, and δ is the angle between the perpendicular line from the point to the rotor center axis and the d-axis.

[0019] Each long boundary line of the air magnetic barrier corresponds to a circle center O'; the magnetic barrier opening angle θ, the magnetic barrier layer center thickness h and the magnetic barrier end width w are determined according to the position of O', r and r'.

[0020] Furthermore, each air magnetic barrier group includes three air magnetic barriers; in the same air magnetic barrier group, eccentric circular air magnetic barriers formed when the centers are not equal are used; the distances between the centers O′ corresponding to the long boundary lines of adjacent air magnetic barrier groups and the coordinate origin O are equal; the angle parameters corresponding to the centers O′ of the long boundary lines in the same air magnetic barrier group are equal; in the four air magnetic barrier groups, the magnetic barrier opening angle θ, the central thickness h of the magnetic barrier layer, and the width w of the magnetic barrier end of the corresponding magnetic barrier layer are equal, and the centers O′ of the long boundary lines of the two air magnetic barrier groups on the upper left and lower right sides are maintained on the q axis, and the centers O′ of the long boundary lines of the two air magnetic barrier groups on the upper right and lower left sides are offset about the q axis The ratio of the center thickness of the first and second air magnetic barrier layers is 0.5-4, and the ratio of the center thickness of the second and third air magnetic barrier layers is 0.5-3; the ratio of the opening angle of the first and second air magnetic barrier layers is 1.1-1.5, and the ratio of the opening angle of the second and third air magnetic barrier layers is 1.1-2; the ratio of the end width of the first and second air magnetic barrier layers is 0.5-2, and the ratio of the end width of the second and third air magnetic barrier layers is 0.5-2; the offset angle of the air magnetic barrier group is 0. It is -3°~3°.

[0021] Furthermore, when the ratio of the center thickness of the first and second air magnetic barrier layers is 2.61, the ratio of the center thickness of the second and third air magnetic barrier layers is 0.91; the ratio of the opening angle of the first and second air magnetic barrier layers is 1.31, the ratio of the opening angle of the second and third air magnetic barrier layers is 1.73; the ratio of the end width of the first and second air magnetic barrier layers is 1.05, the ratio of the end width of the second and third air magnetic barrier layers is 0.95; the offset angle of the air magnetic barrier group is When the angle is -2.45°, the rotor structure improves the output torque of the synchronous reluctance motor and reduces torque ripple.

[0022] The present invention further provides a synchronous reluctance motor, characterized in that the synchronous reluctance motor comprises the rotor structure described in any one of claims 1 to 3.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The long boundary line of the air magnetic barrier layer of the rotor structure is composed of circular arc lines, wherein each circular arc corresponds to a circle center, and can form concentric circular air magnetic barriers and eccentric circular air magnetic barriers. Compared with the rotor structure with concentric circular air magnetic barriers, the rotor structure of the present invention has an increased degree of freedom, and the center thickness of the air magnetic barrier layer, the magnetic barrier opening angle, and the magnetic barrier end width can be adjusted individually by changing the center position and radius of the circle. By changing the angle between the circle center corresponding to the long boundary line and the q-axis, an asymmetric rotor structure can be formed, which can further reduce the torque pulsation of the synchronous reluctance motor. Compared with the rotor structure with concentric circular air magnetic barriers, the rotor structure of the present invention helps to improve the output torque of the synchronous reluctance motor and reduce torque pulsation. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the rotor structure of the present invention;

[0026] Figure 2 Schematic diagram for forming rotor air magnetic barrier boundary;

[0027] Figure 3 This is a schematic diagram of the rotor air magnetic barrier offset;

[0028] Figure 4 is a torque curve diagram of the synchronous reluctance motor of the present invention;

[0029] Figure 5 This is a torque harmonic analysis diagram of the synchronous reluctance motor of the present invention;

[0030] In the figure, 1-first air magnetic barrier layer; 2-second air magnetic barrier layer; 3-third air magnetic barrier layer; 4-first magnetic conductive layer; 5-second magnetic conductive layer; 6-rib; 7-rotating shaft; 8-rotor core. DETAILED DESCRIPTION

[0031] The technical solution of the present invention is clearly and completely described below with reference to the accompanying drawings, but the scope of protection of the present application is not limited thereto.

[0032] like Figure 1 As shown, the present invention provides a synchronous reluctance motor rotor structure, including a rotating shaft 7 and a rotor core 8 mounted on the rotating shaft 7; the rotor core 8 is provided with a plurality of circumferentially distributed air magnetic barrier groups, the air magnetic barrier groups protruding radially inwardly of the rotor core, each air magnetic barrier group including a plurality of air magnetic barrier layers arranged along the q-axis (the q-axis refers to the centerline of the air magnetic barrier group itself), and a magnetic conductive layer is formed between adjacent air magnetic barrier layers; in this embodiment, each air magnetic barrier group is provided with three air magnetic barrier layers, and the air magnetic barrier groups are, from the inside to the outside, a first air magnetic barrier layer 1, a first magnetic conductive layer 4, a second air magnetic barrier layer 2, a second magnetic conductive layer 5, and a third air magnetic barrier layer 3; the portion between the end of each air magnetic barrier layer and the edge of the rotor core 8 is a rib 6, and the rib width in this embodiment is 1 mm.

[0033] like Figure 2 As shown, the cross section of each air magnetic barrier layer along the rotor radial direction is considered to be composed of two long boundary lines and two short boundary coils. The two long boundary lines are the inner and outer long boundary lines respectively, and both satisfy the circular curve parameter equations of formulas (1) to (6);

[0034]

[0035]

[0036] P B P D 2 +O′P D 2 =r′ 2 (3)

[0037] P A P D +O′P D =r′ (4)

[0038]

[0039]

[0040] Among them, P A is the intersection of OO′ and the circle with O′ as the center, P B 、P C is the intersection of the circles with O and O′ as the centers, P D P B With P C The midpoint of the connecting line, r is the radius of the circle with O as the center, and r' is the radius of the circle with O' as the center;

[0041] The two endpoints P of the long boundary line of the air magnetic barrier layer B 、P C And any point of the two short boundary lines satisfies the parametric equation of formula (7);

[0042]

[0043] Where (x, y) is the position coordinate of the point, and δ is the angle between the perpendicular line from the point to the rotor center axis and the d-axis.

[0044] like Figure 3As shown, each long boundary line of the air magnetic barrier corresponds to a circle center O′. When the circle centers are at the same position, a concentric air magnetic barrier is formed, and when the circle centers are unequal, an eccentric air magnetic barrier is formed. The barrier opening angle θ, the barrier layer center thickness h, and the barrier end width w are determined according to the position of O′, r, and r′. In the same air magnetic barrier group, if the circle center O′ corresponding to any long boundary line is not located on the q-axis, a rotor structure asymmetric about the q-axis is formed. In adjacent air magnetic barrier groups, if the circle center O′ corresponding to any long boundary line is at an unequal angle with the d-axis, a rotor structure asymmetric about the d-axis is formed.

[0045] Each air barrier group includes three air barriers; the rotor structure is asymmetric about the d-axis and q-axis; in the same air barrier group, eccentric circular air barriers are formed when the centers are not equal; the distances between the centers O' corresponding to the long boundary lines of adjacent air barrier groups and the coordinate origin O are equal; the angle parameters corresponding to the centers O' of the long boundary lines in the same air barrier group are equal: in the four air barrier groups, the barrier angle θ, the center thickness h of the barrier layer, and the width w of the barrier end are equal; the centers O' of the long boundary lines of the two air barrier groups on the left are maintained on the q-axis, while the centers O' of the long boundary lines of the two air barrier groups on the right are offset about the q-axis. The two air magnetic barrier groups on the right are symmetrical about the d axis; the ratio of the center thickness of the first and second air magnetic barrier layers is 0.5-4, and the ratio of the center thickness of the second and third air magnetic barrier layers is 0.5-3; the ratio of the opening angle of the first and second air magnetic barrier layers is 1.1-1.5, and the ratio of the opening angle of the second and third air magnetic barrier layers is 1.1-2; the ratio of the end width of the first and second air magnetic barrier layers is 0.5-2, and the ratio of the end width of the second and third air magnetic barrier layers is 0.5-2; the offset angle of the air magnetic barrier group is 0. It is -3°~3°.

[0046] Example

[0047] The main parameters of the synchronous reluctance motor of this embodiment are shown in Table 1.

[0048] Table 1 Main parameters of the motor

[0049]

[0050] When the ratio of the center thickness of the first and second air magnetic barrier layers is 2.61, the ratio of the center thickness of the second and third air magnetic barrier layers is 0.91; the ratio of the opening angle of the first and second air magnetic barrier layers is 1.31, the ratio of the opening angle of the second and third air magnetic barrier layers is 1.73; the ratio of the end width of the first and second air magnetic barrier layers is 1.05, the ratio of the end width of the second and third air magnetic barrier layers is 0.95; the offset angle of the air magnetic barrier group When the angle is -2.45°, the rotor structure improves the output torque of the synchronous reluctance motor and reduces torque ripple.

[0051] Figure 4 This is a torque comparison diagram of the synchronous reluctance motor of the present invention and the synchronous reluctance motor with concentric air barriers after optimization using a multi-objective algorithm; the average torque of the synchronous reluctance motor of the present invention is 71.32, and the torque ripple is 4.75%; the average torque of the synchronous reluctance motor with concentric air barriers is 71.72, and the torque ripple is 8.17%; compared with the synchronous reluctance motor with concentric air barriers, the torque ripple of the synchronous reluctance motor of the present invention is reduced by 41.86% without substantially losing output torque.

[0052] Figure 5 This is a torque harmonic analysis diagram of the synchronous reluctance motor of the present invention and the synchronous reluctance motor with concentric air barriers after optimization using a multi-objective algorithm; the 6th to 42nd high-order harmonics of the synchronous reluctance motor of the present invention are reduced by 25.31%, 67.26%, 24.43%, 71.70%, 43.06% and 87.44% respectively compared with the synchronous reluctance motor with concentric air barriers.

[0053] In summary, the simulation results show that the synchronous reluctance motor of the present invention has higher output torque and lower torque ripple than the synchronous reluctance motor with concentric air barriers.

[0054] Any matters not described in the present invention are applicable to the prior art.

Claims

1. A synchronous reluctance motor rotor structure comprising a rotating shaft and a rotor core mounted on the rotating shaft; the rotor core is provided with a plurality of circumferentially distributed air magnetic barrier groups, the air magnetic barrier groups protruding radially inwardly from the rotor core; each air magnetic barrier group comprises a plurality of air magnetic barrier layers arranged along the q-axis, with magnetic conductive layers formed between adjacent air magnetic barrier layers; and characterized in that: The cross section of each air magnetic barrier layer along the rotor radial direction is considered to be enclosed by two long boundary lines and two short boundary lines; the two long boundary lines are the inner and outer long boundary lines respectively, and both satisfy the circular curve parameter equations of formulas (1) to (6); P B P D 2 +O′P D 2 =r′ 2 (3) P A P D +O'P D =r′ (4) Among them, P A is the intersection of OO′ and the circle with O′ as the center, P B 、P C is the intersection of the circles with O and O′ as the centers, P D P B With P C The midpoint of the connecting line, r is the radius of the circle with O as the center, and r' is the radius of the circle with O' as the center; The two endpoints P of the long boundary line of the air magnetic barrier layer B 、P C And any point of the two short boundary lines satisfies the parametric equation of formula (7); Where (x, y) is the position coordinate of the point, and δ is the angle between the perpendicular line from the point to the rotor center axis and the d-axis; Each long boundary line of the air magnetic barrier corresponds to a circle center O'; the magnetic barrier opening angle θ, the magnetic barrier layer center thickness h and the magnetic barrier end width w are determined according to the position of O', r and r'.

2. The synchronous reluctance motor rotor structure according to claim 1, characterized in that: Each air barrier group includes three air barriers; the distances between the centers O' of the long boundary lines of adjacent air barrier groups and the coordinate origin O are equal; the angle parameters corresponding to the centers O' of the long boundary lines in the same air barrier group are equal; in the four air barrier groups, the barrier angle θ, the center thickness h of the barrier layer, and the width w of the barrier end are equal; the centers O' of the long boundary lines of the two air barrier groups on the upper left and lower right sides are maintained on the q axis, and the centers O' of the long boundary lines of the two air barrier groups on the lower left and upper right sides are offset about the q axis.

3. The synchronous reluctance motor rotor structure according to claim 2, characterized in that: The ratio of the center thickness of the first and second air magnetic barrier layers is 0.5-4, and the ratio of the center thickness of the second and third air magnetic barrier layers is 0.5-3; the ratio of the opening angle of the first and second air magnetic barrier layers is 1.1-1.5, and the ratio of the opening angle of the second and third air magnetic barrier layers is 1.1-2; the ratio of the end width of the first and second air magnetic barrier layers is 0.5-2, and the ratio of the end width of the second and third air magnetic barrier layers is 0.5-2; the offset angle of the air magnetic barrier group is 0. It is -3°~3°.

4. The synchronous reluctance motor rotor structure according to claim 3, characterized in that: When the ratio of the center thickness of the first and second air magnetic barrier layers is 2.61, the ratio of the center thickness of the second and third air magnetic barrier layers is 0.91; the ratio of the opening angle of the first and second air magnetic barrier layers is 1.31, the ratio of the opening angle of the second and third air magnetic barrier layers is 1.73; the ratio of the end width of the first and second air magnetic barrier layers is 1.05, the ratio of the end width of the second and third air magnetic barrier layers is 0.95; the offset angle of the air magnetic barrier group When the angle is -2.45°, the rotor structure improves the output torque of the synchronous reluctance motor and reduces torque ripple.

5. A synchronous reluctance motor, characterized in that: The motor comprises the rotor structure according to any one of claims 1 to 4.

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