An oriented silicon steel sheet rotor core and a synchronous reluctance motor

Abstract

The present invention discloses an oriented silicon steel sheet rotor core and a synchronous reluctance motor. The rotor core is assembled by a plurality of oriented silicon steel sheet components with the same structure. The rolling direction of the oriented silicon steel sheets inside each component is parallel to the d-axis of the rotor core, giving full play to the strong magnetic conductivity advantage of the oriented silicon steel sheets in the rolling direction, reducing the d-axis magnetic resistance and increasing the inductance, further improving the saliency ratio and pole ratio of the synchronous reluctance motor, and enhancing the torque density and power factor of the motor, providing a beneficial exploration for the research of synchronous reluctance motors. In addition, the synchronous reluctance motor of the present invention is convenient for production and processing. For a rotor core with a complex magnetic barrier shape and a large number of magnetic barrier layers, it is only necessary to press the oriented silicon steel sheets into a plurality of oriented silicon steel sheet components with the same structure and then assemble them after pressing, avoiding the problem that it is difficult to manufacture an integral rotor core.

Description

Technical Field

[0001] The present invention belongs to the technical field of synchronous reluctance motors, and particularly relates to an oriented silicon steel sheet rotor core and a synchronous reluctance motor. Background Art

[0002] In recent years, due to the gradually decreasing reserves and rising prices of high-performance rare earth permanent magnet materials, the demand for motors with higher performance and lower cost is growing rapidly, and it has become increasingly important to study electromagnetic devices such as reluctance motors with less rare earth permanent magnet materials. Among them, the synchronous reluctance motor can operate without relying on permanent magnet excitation, but follows the principle of minimum reluctance and generates reluctance torque by using the difference in inductance between the d-axis and the q-axis. Due to its advantages of low price, simple processing, reliable structure, and wide speed regulation range, it is widely used in fields such as compressors, household appliances, electric vehicles, and agricultural production.

[0003] The synchronous reluctance motor utilizes the principle of minimum reluctance to generate reluctance torque, which is proportional to the difference in inductance between the d-axis and q-axis (hereinafter referred to as the saliency ratio). The d-axis is the low-reluctance direction, and the q-axis is the high-reluctance direction, with a 90-degree electrical angle difference between them. The rotor core of a traditional synchronous reluctance motor is made of non-oriented silicon steel sheets. Multiple magnetic barriers are punched out on the rotor core, and the saliency ratio has a certain limit. Therefore, it is difficult to increase the reluctance torque further after it reaches a certain value, and there will be a problem that the output torque is difficult to increase further when the load increases. Therefore, how to improve the torque performance of synchronous reluctance motors has become a hot research issue. In existing research, some design methods have been proposed to increase the reluctance torque of synchronous reluctance motors. For the transverse laminated rotor, the magnetic barrier occupancy, the number of magnetic barrier layers, and the shape of the magnetic barrier are optimized and analyzed to change the rotor structure of the motor. For the axial laminated rotor, the number of axial magnetic barriers is increased. These methods mainly improve the saliency ratio of the motor from aspects such as magnetic barrier occupancy, magnetic barrier structure, and topology optimization. When saturation occurs inside the motor, it is difficult to increase the reluctance torque further. The permanent magnet assisted synchronous reluctance motor adds a permanent magnet structure to the magnetic barrier of the synchronous reluctance motor rotor, generating a permanent magnet torque that increases the motor output torque. However, the saliency ratio does not increase significantly, and the motor cost is high. There is a risk of demagnetization of the permanent magnet, reducing the operating stability of the motor. In the design of modern synchronous reluctance motors, the use of high-quality anisotropic magnetic materials can achieve higher efficiency, torque density, and compactness. For example, if the rotor core of the motor uses cold-rolled grain-oriented silicon steel sheet material (Taghavi, S. and P. Pillay, A Novel Grain-Oriented Lamination Rotor Core Assembly for a Synchronous Reluctance Traction Motor With a Reduced Torque Ripple Algorithm. IEEE Transactions on Industry Applications, 2016. 52(0): p. 3729-3738.), the saliency ratio can be increased, and the torque density of the motor can be improved. However, the rolling direction of the grain-oriented silicon steel sheet of this structure is strictly perpendicular to the q-axis of the rotor core. Through the analysis of the magnetic flux path of the motor, this structure fails to fully utilize the advantage of the high magnetic permeability of the grain-oriented silicon steel sheet in the rolling direction. Summary of the Invention

[0004] The object of the present invention is to provide an oriented silicon steel sheet rotor core and a synchronous reluctance motor, so as to solve the technical problems existing in the above-mentioned background technology, apply the oriented silicon steel sheet material to improve the magnetic permeability of the d-axis magnetic field of the synchronous reluctance motor, and improve the output torque; in order to solve the problem of difficult production and manufacturing faced by the traditional integrated rotor core when the magnetic barrier shape is complex and the number of magnetic barrier layers is large, the motor rotor core of this method is assembled by a plurality of oriented silicon steel sheet components with the same structure, which is convenient for large-scale processing and manufacturing, and the rolling direction of each oriented silicon steel sheet component is parallel to the d-axis of the rotor core. By using the characteristics of good magnetic permeability and high magnetic conductivity in the rolling direction of the oriented silicon steel sheet, the saliency ratio of the synchronous reluctance motor is effectively increased, and thus its output torque is improved.

[0005] To achieve the above object, the present invention adopts the following technical solution: An oriented silicon steel sheet rotor core, characterized in that the rotor core is a hollow cylinder structure assembled and bonded by an even number of oriented silicon steel sheet components not less than 2 with the same structure and the same rolling direction, and the through hole at the center of the cylinder structure is the installation hole for the motor shaft; each oriented silicon steel sheet component is formed by stacking and fastening a plurality of identical oriented silicon steel sheets along the axial direction of the motor shaft, and adjacent two oriented silicon steel sheets are fixed together by bonding, and the rolling direction of each oriented silicon steel sheet is the same;

[0006] The rolling direction of the oriented silicon steel sheet is consistent with the d-axis direction of the rotor core, that is, the low magnetic resistance direction at its set position; and two sets of magnetic barrier structures are symmetrically arranged on both sides of the oriented silicon steel sheet; the sizes of the magnetic barriers in each set of magnetic barrier structures decrease from inside to outside in sequence, and the periphery of each magnetic barrier is enclosed by the outer periphery of the oriented silicon steel sheet; each magnetic barrier includes an outer slot parallel to the d-axis direction and an inner slot perpendicular to the q-axis direction, the top of the outer slot is an arc segment, the two side edges of the outer slot are parallel to the d-axis direction, and the bottom of the outer slot is connected to the top of the inner slot; the two side edges of the inner slot are perpendicular to the q-axis direction, and the bottom of the inner slot is parallel to the q-axis direction; the tops of all the outer slots of the magnetic barriers on a plurality of oriented silicon steel sheets located in the same radial plane of the rotor core are located on the same circumference, and the central axis of this circumference coincides with the central axis of the rotor core; the closest edge lines of two adjacent oriented silicon steel sheets among a plurality of oriented silicon steel sheets located in the same radial plane are parallel to the q-axis direction, and there is a certain distance between the bottom of the inner slot on the oriented silicon steel sheet and its closest edge line to enhance the mechanical strength of the motor; the inside of the magnetic barrier is empty or filled with non-magnetic materials.

[0007] Furthermore, the present invention provides an oriented silicon steel sheet rotor core synchronous reluctance motor, characterized in that the synchronous reluctance motor includes the rotor core as described above, and further includes a stator core, an armature winding, and a motor shaft. The stator core is made of non-oriented silicon steel sheet material, which is axially laminated and fastened in the same state by a plurality of identical annular non-oriented silicon steel sheets with teeth uniformly arranged inside; the armature winding is a three-phase symmetric distributed winding, which is arranged in the slit grooves formed by the teeth and yokes inside the stator core; the axial lengths of the stator core and the rotor core are the same and there is a gap between them, and the width of the gap is between 0.2 mm and 1 mm; during assembly, the axes of the rotor core, the stator core, and the motor shaft coincide.

[0008] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0009] 1. The rotor core of the present invention is assembled by a plurality of oriented silicon steel sheet components with the same structure. The rolling direction of the oriented silicon steel sheets inside each component is parallel to the d-axis of the rotor core, giving full play to the strong magnetic conductivity advantage of the oriented silicon steel sheets in the rolling direction, reducing the d-axis magnetic resistance and increasing the inductance, further improving the saliency ratio and pole ratio of the synchronous reluctance motor, and enhancing the torque density and power factor of the motor, providing a beneficial exploration for the research of synchronous reluctance motors.

[0010] 2. It is convenient for production and processing. For rotor cores with complex magnetic barrier shapes and a large number of magnetic barrier layers, only need to press the oriented silicon steel sheets into a plurality of oriented silicon steel sheet components with the same structure, and then assemble them after pressing, avoiding the problem that it is not easy to manufacture an integrated rotor core. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a schematic structural diagram of an embodiment of an oriented silicon steel sheet rotor core of the present invention;

[0012] Figure 2 is a schematic structural diagram of an oriented silicon steel sheet component of an embodiment of an oriented silicon steel sheet rotor core of the present invention (the arrow in the figure indicates the rolling direction);

[0013] Figure 3 is a schematic structural diagram of an embodiment of an oriented silicon steel sheet rotor core synchronous reluctance motor of the present invention;

[0014] Figure 4 is a schematic structural diagram of a traditional U-shaped synchronous reluctance motor (the rotor core 7 is made of non-oriented silicon steel sheet);

[0015] Figure 5 Shown is the d-axis inductance (L d of SynRMa), q-axis inductance (Lq of SynRM a) and the d-axis inductance (L d of SynRM b), q-axis inductance (L q of SynRM b) as the current density increases;

[0016] Figure 6 The figure shows the comparison diagrams of the saliency ratio of the synchronous reluctance motor in Embodiment 1 (Saliency ratio of SynRM a), power factor (Power factor of SynRM a) and the saliency ratio of the traditional U-shaped synchronous reluctance motor (Saliency ratio of SynRM b), power factor (Power factor of SynRM b) as the current density increases;

[0017] Figure 7 The figure shows the comparison diagram of the torque of the synchronous reluctance motor (SynRM a) in Embodiment 1 and the traditional U-shaped synchronous reluctance motor (SynRM b) under the same external conditions;

[0018] Figure 8 The figure shows the magnetic field line distribution diagram of the synchronous reluctance motor in Embodiment 1 during actual operation;

[0019] Description of the drawings: 1. Stator core; 2. Armature winding; 3. Air gap; 4. Grain-oriented silicon steel sheet; 5. Magnetic barrier; 6. Motor shaft; 7. Rotor core (of the traditional U-shaped synchronous reluctance motor). Detailed implementation manners

[0020] The technical solutions of the present invention will be clearly and completely described below in conjunction with the drawings and specific implementation manners, without limiting the protection scope of this application thereby.

[0021] The present invention provides a grain-oriented silicon steel sheet rotor core, characterized in that the rotor core is a hollow cylindrical structure assembled and bonded by an even number of grain-oriented silicon steel sheet assemblies not less than 2 with the same structure and the same rolling direction, and the through hole at the center of the cylindrical structure is the motor shaft installation hole; each grain-oriented silicon steel sheet assembly is formed by stacking and fastening a plurality of the same grain-oriented silicon steel sheets along the axial direction of the motor shaft, and the adjacent two grain-oriented silicon steel sheets are fixed together by bonding, and the rolling direction of each grain-oriented silicon steel sheet is the same.

[0022] The rolling direction of the grain-oriented silicon steel sheet is consistent with the d-axis direction of the rotor core, which is the low magnetic resistance direction at its set position. And two sets of magnetic barrier structures are symmetrically arranged on both sides of the grain-oriented silicon steel sheet; the sizes of the magnetic barriers in each set of magnetic barrier structures decrease successively from inside to outside (with the side close to the symmetry axis of the grain-oriented silicon steel sheet being the inside), and the periphery of each magnetic barrier is enclosed by the outer periphery of the grain-oriented silicon steel sheet; each magnetic barrier includes an outer groove parallel to the d-axis direction and an inner groove perpendicular to the q-axis direction. The top of the outer groove is an arc segment, the two side edges of the outer groove are parallel to the d-axis direction, and the bottom of the outer groove is connected to the top of the inner groove; the two side edges of the inner groove are perpendicular to the q-axis direction, and the bottom of the inner groove is parallel to the q-axis direction; the tops of all the outer grooves of the magnetic barriers on multiple grain-oriented silicon steel sheets located in the same radial plane of the rotor core are located on the same circumference, and the central axis of this circumference coincides with the central axis of the rotor core; the closest edge lines of two adjacent grain-oriented silicon steel sheets among multiple grain-oriented silicon steel sheets located in the same radial plane are all parallel to the q-axis direction, and there is a certain distance between the bottom of the inner groove on the grain-oriented silicon steel sheet and its closest edge line to improve the mechanical strength of the motor; the inside of the magnetic barrier is empty or filled with non-magnetic materials.

[0023] On the premise that the mechanical strength of the rotor core permits, the number of poles in the rotor (i.e., the number of grain-oriented silicon steel sheet assembly structures), the number of layers, shape, and size of the internal magnetic barriers of the grain-oriented silicon steel sheet can be adjusted as needed.

[0024] Furthermore, the present invention provides a grain-oriented silicon steel sheet rotor core synchronous reluctance motor, which is characterized in that the synchronous reluctance motor includes the rotor core as described above, and also includes a stator core, an armature winding, and a motor shaft. The stator core is made of non-oriented silicon steel sheet material, and is formed by axially laminating and fastening a plurality of identical annular non-oriented silicon steel sheets with teeth uniformly arranged inside in the same state; the armature winding is a three-phase symmetric distributed winding, which is arranged in the slit grooves formed by the teeth and yokes inside the stator core; the axial lengths of the stator core and the rotor core are the same and there is an air gap with a width between 0.2 mm and 1 mm left between them. During assembly, the axis of the rotor core, the axis of the stator core, and the axis of the motor shaft coincide.

[0025] This synchronous reluctance motor is obtained by replacing the rotor core of the traditional U-shaped synchronous reluctance motor with the grain-oriented silicon steel sheet rotor core of the present invention.

[0026] The innovation of the synchronous reluctance motor of the present invention lies in the rotor core structure. The rotor core of the traditional synchronous reluctance motor is laminated by non-oriented silicon steel sheets, and the anti-saturation ability of the motor is poor, so its torque density is limited. The rotor core of the synchronous reluctance motor of the present invention is assembled by a plurality of identical oriented silicon steel sheet assemblies with the rolling direction consistent with the d-axis direction of the rotor core, which is convenient for large-scale processing and manufacturing and can give full play to the unidirectional magnetic conduction advantage of the oriented silicon steel sheet, can minimize the d-axis magnetic resistance, increase the saliency ratio of the motor, and thus can effectively improve the output torque of the motor and reduce the size and weight of the motor under the same working load.

[0027] Embodiment 1

[0028] This embodiment provides an oriented silicon steel sheet rotor core (see Figure 1-2 ), which is characterized in that the rotor core is a hollow cylinder structure assembled and bonded by four identical oriented silicon steel sheet assemblies with the same rolling direction. The through hole at the center of the cylinder structure is the installation hole for the motor shaft; each oriented silicon steel sheet assembly is formed by stacking and fastening a plurality of identical oriented silicon steel sheets 4 along the axial direction of the motor shaft. Adjacent two oriented silicon steel sheets 4 are fixed together by bonding, and the rolling direction of each oriented silicon steel sheet 4 is the same.

[0029] The rolling direction of the oriented silicon steel sheet 4 is consistent with the d-axis direction of the rotor core, that is, the low magnetic resistance direction at its setting position. And two groups of magnetic barrier structures 5 are symmetrically arranged on both sides of the oriented silicon steel sheet; the sizes of the three magnetic barriers in each group of magnetic barrier structures decrease sequentially from inside to outside (taking the side close to the symmetry axis of the oriented silicon steel sheet as the inside). The periphery of each magnetic barrier is enclosed by the outer periphery of the oriented silicon steel sheet; each magnetic barrier includes an outer groove parallel to the d-axis direction and an inner groove perpendicular to the q-axis direction. The top of the outer groove is an arc segment, the two side edges of the outer groove are parallel to the d-axis direction, and the bottom of the outer groove is connected to the top of the inner groove; the two side edges of the inner groove are perpendicular to the q-axis direction, and the bottom of the inner groove is parallel to the q-axis direction; the tops of all the outer grooves of the magnetic barriers on the plurality of oriented silicon steel sheets located in the same radial plane of the rotor core are located on the same circumference, and the central axis of this circumference coincides with the central axis of the rotor core; the closest edge lines of two adjacent oriented silicon steel sheets among the plurality of oriented silicon steel sheets located in the same radial plane are parallel to the q-axis direction, and the distance between the bottom of the inner groove on the oriented silicon steel sheet and its closest edge line is 0.3 mm to improve the mechanical strength of the motor; the inside of the magnetic barrier is empty or filled with non-magnetic materials.

[0030] Furthermore, the present invention provides an oriented silicon steel sheet rotor core synchronous reluctance motor (see Figure 3), characterized in that the synchronous reluctance motor includes the rotor core as described above, and further includes a stator core 1, an armature winding 2, and a motor shaft 6. The stator core 1 is made of non-oriented silicon steel sheet material, which is formed by axially laminating and fastening a plurality of identical annular non-oriented silicon steel sheets with teeth uniformly arranged inside in the same state; the armature winding 2 is a three-phase symmetrical distributed winding, which is arranged in the slit grooves formed by the teeth and yoke inside the stator core 1; the axial lengths of the stator core 1 and the rotor core are the same and there is an air gap 3 between them, and the width of the air gap 3 is 0.5 mm. During assembly, the axes of the rotor core, the stator core 1, and the motor shaft 6 coincide. The rotor core is sleeved and fixedly installed on the motor shaft 6, and the stator core 1 is fixed on the motor base through installation fittings.

[0031] The parameters of the synchronous reluctance motor in this embodiment are shown in Table 1.

[0032] Table 1 Structural parameters of the synchronous reluctance motor

[0033]

[0034] The synchronous reluctance motor in this embodiment is subjected to simulation modeling, and the transient field modeling and simulation analysis of the synchronous reluctance motor with this oriented silicon steel sheet assembly are carried out using the electromagnetic field finite element module Maxwell 2D. The motor model is as Figure 3 (SynRMa) shown.

[0035] As Figure 1 shown, the motor rotor core in this embodiment is a cylindrical structure assembled by four identical oriented silicon steel sheet assemblies. The arrow direction in the figure represents the rolling direction of the oriented silicon steel sheet assembly, and its direction is consistent with the d-axis direction of the rotor core, that is, the low magnetic resistance direction. As Figure 2 shown, each oriented silicon steel sheet assembly is formed by axially laminating and fastening a plurality of identical oriented silicon steel sheets in the same state. Two groups of magnetic barrier structures are symmetrically arranged on both sides of each layer of oriented silicon steel sheet. The magnetic barriers are empty or filled with non-magnetic conductive materials. The arrow direction in the figure is the rolling direction of the oriented silicon steel sheet. Placing them in this way can effectively increase the d-axis inductance and reduce the q-axis inductance, so that the saliency ratio of the motor is significantly improved, thereby increasing the motor output torque.

[0036] Figure 4 is a traditional U-shaped synchronous reluctance motor (SynRMb). The stator core structure and the armature winding are the same as those in the synchronous reluctance motor of this embodiment. The rotor structure includes a rotor core 7. A magnetic barrier structure 5 is provided on the rotor core 7. The rotor core 7 is laminated from non-oriented silicon steel sheets. Each magnetic barrier structure 5 of the non-oriented silicon steel sheet contains three layers of magnetic barriers, and the shape of the magnetic barrier is approximately U-shaped.

[0037] Figure 5 The d-axis inductance (L d of SynRMa), q-axis inductance (L q of SynRMa) of the synchronous reluctance motor in this embodiment and the d-axis inductance (L d of SynRMb), q-axis inductance (L q of SynRMb) of the traditional U-shaped synchronous reluctance motor are shown in the comparative schematic diagram of the change with current density. It can be seen that the d-axis inductance (L d ) of the two motors decreases rapidly with the increase of current density, and the decreasing amplitude is first fast and then slow. Because when the current density is 4 A / mm 2 , the silicon steel sheet inside the motor is near the knee point of its B-H curve. As the current density increases, the rotor magnetic bridge will become saturated, resulting in a large increase in magnetic resistance. Therefore, L d decreases rapidly. When the current density continues to increase, the silicon steel sheet in the motor has reached severe saturation, and the increase in its magnetic resistance is small. Therefore, L d decreases slowly; the q-axis inductance (L q ) decreases less with the increase of current density because the quadrature-axis magnetic resistance is the magnetic resistance of non-magnetic conductive materials, and its value is large and not sensitive to current changes. It can be clearly seen from the comparison in the figure that the motor in this example shows a higher d-axis inductance and a lower q-axis inductance at the same operating point. This is because when the current density is large, the grain-oriented silicon steel sheet has strong anti-saturation ability, and the magnetic force lines can still flow smoothly through the grain-oriented silicon steel sheet, which makes its d-axis magnetic resistance smaller, that is, the d-axis inductance is higher. Therefore, the use of grain-oriented silicon steel sheet material in the rotor core improves the saliency ratio of the motor, increases the output torque, and reduces the motor size under the same operating load.

[0038] Figure 6 The comparative schematic diagram of the saliency ratio (Saliency ratio of SynRMa), power factor (Power factor of SynRMa) of the synchronous reluctance motor in this embodiment and the saliency ratio (Saliency ratio of SynRMb), power factor (Power factor of SynRMb) of the traditional U-shaped synchronous reluctance motor with the change of current density is shown. The saliency ratio is defined as the ratio of L d and L q . It can be seen from the figure that the saliency ratio of the motor in this example is higher. This is because the motor in this example uses grain-oriented silicon steel sheet material, making L d larger and the changing trend of the saliency ratio with the increase of current density is roughly the same as that of L d . Since the power factor is positively correlated with the saliency ratio, the motor in this embodiment has a higher power factor.

[0039] Figure 7The figure shows a comparison schematic diagram of the output torque of the synchronous reluctance motor (SynRMa) of this embodiment and a traditional U-shaped synchronous reluctance motor (SynRMb) under the same applied conditions. It can be clearly seen from the figure that the synchronous reluctance motor of this embodiment has a higher output torque than the traditional U-shaped synchronous reluctance motor. This is because the use of grain-oriented silicon steel material effectively increases the d-axis inductance and improves the saliency ratio of the motor, thereby increasing the motor output torque, which proves the feasibility of the technical solution of the present invention.

[0040] Figure 8 The figure shows the magnetic field line distribution diagram of the synchronous reluctance motor of this embodiment during actual operation. It can be clearly seen from the figure that there are more magnetic field lines in the d-axis direction of the rotor core of the motor. This is because the rolling direction of the grain-oriented silicon steel sheet is parallel to the d-axis of the rotor core, making the magnetic resistance in the d-axis direction very small. According to the principle of minimum magnetic resistance, more magnetic field lines can easily pass through.

[0041] The rotor core of the present invention is assembled by a plurality of grain-oriented silicon steel sheet assemblies with the same structure and the rolling direction consistent with the d-axis of the rotor core. By utilizing the characteristics of high magnetic permeability and strong magnetic conduction ability in the rolling direction of the grain-oriented silicon steel sheet, the saliency ratio and saliency pole rate of the motor are effectively improved, thereby enhancing the torque density and power factor of the motor and improving the electromagnetic performance of the motor.

[0042] Although the present invention has been described in conjunction with its specific embodiments, it should be understood that the invention can be further modified. This application intends to cover any variations, uses, or changes to the present invention in general, including those different from the disclosed content herein in the known or customary practices within the technical field to which the present invention pertains, as well as those that can be applied to the basic features proposed above.

[0043] Since the present invention can be implemented in several forms without departing from the spirit of the basic features of the present invention, it should be understood that unless specifically stated, the above-described embodiments are not intended to limit the present invention, but should be broadly understood within the spirit and scope of the present invention defined in the appended claims. The described embodiments should be considered explanatory in all respects and not restrictive.

[0044] Matters not described in the present invention are applicable to the prior art.

Claims

1. An oriented silicon steel sheet rotor core, characterized in that, The rotor core is a hollow cylinder structure assembled and bonded by an even number of grain-oriented silicon steel sheet assemblies not less than 2 with the same structure and the same rolling direction. The through hole at the center of the cylinder structure is the installation hole for the motor shaft. Each grain-oriented silicon steel sheet assembly is formed by stacking and pressing a plurality of identical grain-oriented silicon steel sheets along the axial direction of the motor shaft and fastening them. Adjacent two grain-oriented silicon steel sheets are fixed together by bonding, and the rolling direction of each grain-oriented silicon steel sheet is the same. The rolling direction of the grain-oriented silicon steel sheet is consistent with the d-axis direction of the rotor core, that is, the low magnetic resistance direction at its set position. And two sets of magnetic barrier structures are symmetrically arranged on both sides of the grain-oriented silicon steel sheet. The sizes of the magnetic barriers in each set of magnetic barrier structures decrease sequentially from inside to outside, and the periphery of each magnetic barrier is enclosed by the outer periphery of the grain-oriented silicon steel sheet. Each magnetic barrier includes an external slot parallel to the d-axis direction and an internal slot perpendicular to the q-axis direction. The top of the external slot is an arc segment, the two side edges of the external slot are parallel to the d-axis direction, and the bottom of the external slot is connected to the top of the internal slot. The two side edges of the internal slot are perpendicular to the q-axis direction, and the bottom of the internal slot is parallel to the q-axis direction. The tops of all the external slots of the magnetic barriers on the grain-oriented silicon steel sheets located in the same radial plane of the rotor core are located on the same circumference, and the central axis of this circumference coincides with the central axis of the rotor core. The closest edge lines of two adjacent grain-oriented silicon steel sheets located in the same radial plane are all parallel to the q-axis direction, and the bottom of the internal slot on the grain-oriented silicon steel sheet has a certain distance from the closest edge line to improve the mechanical strength of the motor. The inside of the magnetic barrier is empty or filled with non-magnetic materials.

2. The grain-oriented silicon steel sheet rotor core according to claim 1, wherein, The rotor core is assembled and bonded by four grain-oriented silicon steel sheet assemblies with the same structure and the same rolling direction.

3. The grain-oriented silicon steel sheet rotor core according to claim 1, wherein Each set of magnetic barrier structures on the grain-oriented silicon steel sheet contains three magnetic barriers.

4. A grain-oriented silicon steel sheet rotor core according to claim 1, wherein The distance between the bottom of the internal slot on the grain-oriented silicon steel sheet and the closest edge line is 0.3 mm.

5. A synchronous reluctance motor with an oriented silicon steel sheet rotor core, characterized in that The synchronous reluctance motor includes the rotor core as described in any one of claims 1-4, and also includes a stator core, an armature winding, and a motor shaft. The stator core is made of non-oriented silicon steel sheet material, and is formed by axially stacking and pressing a number of identical annular non-oriented silicon steel sheets with uniformly arranged teeth inside in the same state. The armature winding is a three-phase symmetric distributed winding, which is arranged in the slit slots formed by the teeth and the yoke inside the stator core. The axial lengths of the stator core and the rotor core are the same and there is a gap of one circle between them. The width of the gap is between 0.2 mm and 1 mm. During assembly, the axis of the rotor core, the axis of the stator core and the axis of the motor shaft coincide. This synchronous reluctance motor is obtained by replacing the rotor core of the traditional U-shaped synchronous reluctance motor with the grain-oriented silicon steel sheet rotor core as described in any one of claims 1-4.

6. A salient pole synchronous reluctance motor with an oriented silicon steel sheet rotor core according to claim 5, characterized in that, The width of the gap is 0.5 mm.

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