A kind of anti salient pole permanent magnet synchronous motor decoupling magnetic magnetic circuit and armature main magnetic circuit

Abstract

The application discloses a demagnetization magnetic circuit and armature main magnetic circuit decoupling anti salient pole permanent magnet synchronous motor, and relates to the technical field of motor research and development. A first magnetic barrier is located on a q axis, an arc-shaped magnetic barrier is designed on the edge of a rotor core, a second magnetic barrier is located on a d axis, a strip-shaped magnetic barrier is designed on the inside of the rotor core close to the edge, a third magnetic barrier is symmetrically arranged on both sides of the d axis by two magnetic isolation magnetic barriers, is designed on the inside of the rotor core close to the main shaft, a direct axis bypass magnetic bridge is arranged at the first magnetic barrier, a permanent magnet one is symmetrically arranged on both sides of the d axis in a V shape, the inside end is connected with the two magnetic isolation magnetic barriers, the outside end is provided with a permanent magnet two in the axial direction, a permanent magnet three is vertically arranged on both sides of the d axis in a character string shape and is embedded in the inside of the rotor core at the bottom end of the second magnetic barrier. By decoupling the demagnetization magnetic circuit and the armature main magnetic circuit, the armature reaction demagnetization magnetic circuit reluctance is reduced, when the motor is in the speed expansion state, the demagnetization magnetic field path is changed to reduce the demagnetization risk of the permanent magnet, and safe and reliable operation in the full speed range is realized.

Description

Technical Field

[0001] This invention relates to the field of motor research and development technology, specifically to an anti-salient pole permanent magnet synchronous motor that decouples the excitation magnetic circuit and the armature main magnetic circuit. Background Technology

[0002] Compared to traditional asynchronous motors, DC motors, switched reluctance motors, and electrically excited synchronous motors, permanent magnet synchronous motors (PMSMs) offer advantages such as simple structure, reliable operation, high power density, and high efficiency. Therefore, PMSMs have broad application prospects in electric drive systems, CNC machine tool spindle systems, and flywheel energy storage systems.

[0003] In conventional permanent magnet synchronous motors, the permanent magnets are located in the direct-axis magnetic circuit, resulting in a lower direct-axis inductance than the quadrature-axis inductance. When the motor needs to operate at high speeds, a field weakening method, which increases the direct-axis demagnetizing current, is used to increase the motor speed. As the field weakening current increases, the quadrature-axis current decreases, thereby reducing the permanent magnet torque and lowering the motor efficiency.

[0004] The direct-axis inductance of an anti-salient-pole permanent magnet synchronous motor is greater than its quadrature-axis inductance. Throughout the full speed range, the direct-axis current transitions from magnetizing to demagnetizing current, resulting in a wide current angle adjustment range, making it more suitable for applications with a wide constant power speed range. However, like traditional permanent magnet synchronous motors, anti-salient-pole permanent magnet synchronous motors face the risk of irreversible demagnetization of the permanent magnets during deep magnet weakening, which can lead to reduced motor performance and even shorten the motor's lifespan. Summary of the Invention

[0005] To address the shortcomings of the prior art, this invention provides an anti-salient pole permanent magnet synchronous motor that decouples the excitation magnetic circuit and the armature main magnetic circuit. By decoupling the excitation magnetic circuit and the armature main magnetic circuit, it reduces the magnetic resistance of the armature reaction demagnetizing magnetic circuit. When the motor is used for field weakening and speed expansion, it reduces the risk of permanent magnet demagnetization by changing the path of the demagnetizing magnetic field, thus achieving safe and reliable operation across the entire speed range.

[0006] In order to achieve the above object, the present application adopts the following technical scheme: a demagnetization magnetic circuit and an armature main magnetic circuit decoupling transverse salient pole permanent magnet synchronous motor, comprising a stator and a rotor, the stator comprises a stator core and a stator winding, the inner wall of the stator core is uniformly provided with a plurality of stator slots in the circumferential direction, the stator winding is wound and arranged in the plurality of stator slots, the rotor comprises a rotor core and a permanent magnet group, the rotor core is coaxially assembled in the stator core and an air gap is left between the two, the permanent magnet group is installed inside the rotor core, the rotor core is further provided with a transaxial magnetic barrier and a direct axis bypass magnetic bridge, the transaxial magnetic barrier comprises 2p first magnetic barriers, second magnetic barriers and third magnetic barriers, the first magnetic barriers are located at the axis position of the q axis, arc-shaped magnetic barriers are uniformly arranged in the arc-shaped slots corresponding to the edge of the rotor core, the second magnetic barriers are located at the axis position of the d axis, strip-shaped magnetic barriers are uniformly arranged in the rotor core adjacent to the edge position, the third magnetic barriers are composed of two magnetic barriers, the two magnetic barriers are symmetrically arranged on both sides of the d axis and are uniformly arranged in the rotor core adjacent to the main shaft position, the number of the direct axis bypass magnetic bridge is 2p, the direct axis bypass magnetic bridge is arc-shaped and is matched with the corresponding first magnetic barrier, the permanent magnet group comprises 4p permanent magnet one, permanent magnet two and permanent magnet three, two permanent magnet one in each group are symmetrically arranged on both sides of the d axis and are embedded in the middle position of the rotor core, the inner side of each group of two permanent magnet one is connected with the two magnetic barriers of the corresponding third magnetic barrier, the outer side of each group of two permanent magnet one is embedded with permanent magnet two along the axis direction, the cross-sectional area of the permanent magnet two is smaller than that of the permanent magnet one, the permanent magnet three is arranged in a vertical line on both sides of the d axis and is embedded in the corresponding second magnetic barrier bottom end of the rotor core, wherein p is the pole pair number of the motor.

[0007] Further, the number of the stator slots is a multiple of 3.

[0008] Further, the material of the permanent magnet one is ferrite, and the materials of the permanent magnet two and the permanent magnet three are neodymium iron boron.

[0009] Compared with the prior art, the present application has the following beneficial effects: by decoupling the excitation magnetic circuit and the armature main magnetic circuit, the present application reduces the armature reaction magnetic circuit reluctance, thereby realizing the field weakening speed expansion of the permanent magnet synchronous motor, and the unique direct axis bypass magnetic bridge increases the direct axis inductance, so that the motor has a magnetic characteristic, when the motor is low speed and heavy load, the direct axis magnetic current is passed in the armature winding to improve the torque output capacity, when the motor is field weakening speed expansion, the demagnetization magnetic field path can be changed, the risk of permanent magnet demagnetization is reduced, the safe and reliable operation in the full speed range is realized, and the operation performance and service life of the motor are improved. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 is the overall structure schematic diagram of the motor of the present application, which takes an 8-pole 48-slot motor as an example;

[0011] Figure 2 is Figure 1 the structure schematic diagram of the rotor in the present application;

[0012] Figure 3 is the magnetic field path schematic diagram of the motor of the present application after decoupling the main magnetic circuit of the armature and the magnetic circuit of the magnetic coupling.

[0013] In the figure: 1 - stator core; 2 - stator slot; 3 - stator winding; 4 - rotor core; 5 - first magnetic barrier; 6 - second magnetic barrier; 7 - magnetic barrier; 8 - direct axis bypass magnetic bridge; 9 - permanent magnet one; 10 - permanent magnet two; 11 - permanent magnet three. DETAILED DESCRIPTION

[0014] The technical solutions in the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0015] As Figures 1 to 3 shown, a counter salient pole permanent magnet synchronous motor decoupling the main magnetic circuit of the armature and the magnetic circuit of the magnetic coupling includes a stator and a rotor.

[0016] As Figure 1 shown, the stator includes a stator core 1 and a stator winding 3, the inner wall of the stator core 1 is uniformly provided with a plurality of stator slots 2 in the circumferential direction, the number is generally a multiple of 3, the stator winding 3 is wound and arranged in the plurality of stator slots 2, the stator winding 3 is made of enameled wire winding, double-layer distributed winding is adopted, coil elements are embedded and arranged in each stator slot 2 of the stator core 1, when one coil edge of the coil element is embedded in the upper layer of the nth stator slot 2, the other coil edge is embedded in the lower layer of the nth+y stator slot 2, n is an integer representing the corresponding number of the stator slot 2, and y is the pitch.

[0017] As Figure 2As shown, the rotor includes a rotor core 4 and a permanent magnet group, the rotor core 4 is coaxially assembled in the stator core 1 and an air gap is left between them. The permanent magnet group is installed inside the rotor core 4, and the rotor core 4 is also provided with a q-axis magnetic barrier and a d-axis bypass magnetic bridge 8. The q-axis magnetic barrier includes 2p first magnetic barriers 5, 2p second magnetic barriers 6 and 2p third magnetic barriers. The first magnetic barrier 5 is located at the axis position of the q-axis, adopts an arc-shaped magnetic barrier and is uniformly arranged in the arc-shaped slot corresponding to the edge of the rotor core 4. The second magnetic barrier 6 is located at the axis position of the d-axis, adopts a strip-shaped magnetic barrier and is uniformly arranged in the rotor core 4 adjacent to the edge position. The third magnetic barrier is composed of two magnetic barriers 7, which are symmetrically arranged on both sides of the d-axis and are uniformly arranged in the rotor core 4 adjacent to the main shaft position. The number of the d-axis bypass magnetic bridge 8 is 2p, and the d-axis bypass magnetic bridge 8 is arc-shaped and is matched with the corresponding first magnetic barrier 5. The permanent magnet group includes 4p permanent magnets one 9, 4p permanent magnets two 10 and 4p permanent magnets three 11. The two permanent magnets one 9 are symmetrically arranged on both sides of the d-axis and are embedded in the middle position of the rotor core 4, and the two permanent magnets one 9 are connected with the two magnetic barriers 7 of the corresponding third magnetic barrier, and the two permanent magnets one 9 are embedded with the permanent magnets two 10 at the outer side of the axis direction, and the cross-sectional area of the permanent magnets two 10 is smaller than that of the permanent magnets one 9. The two permanent magnets three 11 are vertically arranged on both sides of the d-axis and are embedded in the bottom end of the corresponding second magnetic barrier 6 in the rotor core 4. Wherein p is the pole pair number of the motor.

[0018] As Figures 1 to 2 For example, the 8-pole 48-slot motor in the prior art has 4 pole pairs, and the number of the first magnetic barrier 5, the second magnetic barrier 6 and the third magnetic barrier is 8, wherein the number of the magnetic barrier 7 of the third magnetic barrier is 16, the 8 first magnetic barriers 5 and the 8 third magnetic barriers are alternately and uniformly arranged along the circumference of the rotor core 4, the 8 second magnetic barriers 6 are located at the axis position of the 8 third magnetic barriers, the first magnetic barrier 5 and the second magnetic barrier 6 are close to the outer surface of the rotor core 4, the third magnetic barrier is close to the main shaft of the permanent magnet one 9, each magnetic barrier 7 is connected with a permanent magnet one 9, the material of the permanent magnet one 9 is ferrite, and each permanent magnet one 9 is provided with a permanent magnet two 10 at the outer side of the axis, but the area is smaller than that of the permanent magnet one 9, and there are two permanent magnets three 11 perpendicular to the second magnetic barrier 6 on both sides of the second magnetic barrier 6, and the materials of the permanent magnet two 10 and the permanent magnet three 11 are neodymium iron boron.

[0019] In the permanent magnet synchronous motor, the d-axis bypass magnetic bridge 8 provides a path for the d-axis armature reaction, realizes the decoupling of the excitation magnetic circuit and the armature main magnetic circuit, and combines the advantages of the permanent magnet motor and the synchronous motor. Figure 3As shown in path b, the first magnetic barrier 5 is located on the q-axis, between permanent magnet 9, permanent magnet 10, and the direct-axis bypass magnetic bridge 8. It not only reduces magnetic leakage but also increases quadrature-axis magnetic reluctance. The second magnetic barrier 6 is located at the center of the I-shaped permanent magnet 11, similarly reducing magnetic leakage and increasing quadrature-axis magnetic reluctance. The third magnetic barrier is located at the centerline of the V-shaped permanent magnet 9, comprising two triangular magnetic barriers 7, which reduce magnetic leakage.

[0020] To improve the direct-axis inductance, an arc-shaped direct-axis bypass magnetic bridge 8 is designed in the direct-axis magnetic circuit, which also enhances the mechanical strength of the rotor at high speeds. When the motor is under low-speed heavy load, a direct-axis magnetizing current is passed through the armature winding, improving the torque output capability; when the motor is under field weakening and speed expansion, most of the demagnetizing magnetic field passes directly through... Figure 3 Paths a and b in the circuit protect the permanent magnet 9. Therefore, this invention can reduce the armature reaction demagnetizing reluctance and achieve field weakening speed extension of the permanent magnet synchronous motor by decoupling the excitation magnetic circuit and the armature main magnetic circuit. At the same time, its unique rotor design can change the path of the demagnetizing magnetic field, reduce the demagnetization risk of the ferrite permanent magnet 9, and achieve safe and reliable operation in the entire speed range.

[0021] This invention reduces the impact of armature reaction on the magnetic reluctance of the demagnetizing magnetic circuit by decoupling the excitation magnetic circuit and the armature main magnetic circuit, thereby realizing the field weakening speed extension of the permanent magnet synchronous motor. The setting of the quadrature axis magnetic barrier and the direct axis bypass magnetic bridge 8 makes the direct axis inductance of the motor greater than the quadrature axis inductance, giving it anti-salient pole characteristics. The large direct axis inductance can reduce the required direct axis field weakening current, effectively improve the easy demagnetization characteristics of permanent magnets, and improve the operating efficiency of the motor. Moreover, the large direct axis inductance is conducive to widening the constant power speed regulation range of the motor and increasing the maximum speed of the motor.

[0022] Maintaining a positive direct-axis current during motor operation serves two purposes: firstly, it generates driving reluctance torque; secondly, it expands the adjustment range of the direct-axis current. This increases both the electromagnetic torque of the motor and widens its constant power speed regulation range. In this configuration, the direct-axis current acts as the excitation current. Above the base speed, as the speed increases, the direct-axis current gradually decreases, thus achieving field weakening control similar to that of a DC motor.

[0023] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of the equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0024] Furthermore, it should be understood that although the specification is described in terms of embodiments, not every embodiment includes only one independent technical solution, and the specification is described in this way only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that those skilled in the art can understand.

Claims

1. A kind of anti salient pole permanent magnet synchronous motor of decoupling magnetic magnetic circuit and armature main magnetic circuit, including stator and rotor, the stator includes stator core (1) and stator winding (3), the inner wall of stator core (1) is uniformly provided with multiple stator line slot (2) along the circumference direction, stator winding (3) is wound and arranged in multiple stator line slot (2), the rotor includes rotor core (4) and permanent magnet group, rotor core (4) is coaxially assembled in stator core (1) and the air gap between the two, the permanent magnet group is installed in the inside of rotor core (4), it is characterized by: The rotor core (4) is also provided with a quadrature axis magnetic barrier and a direct axis bypass magnetic bridge (8), the quadrature axis magnetic barrier includes first magnetic barriers (5), second magnetic barriers (6) and third magnetic barriers, each of which is located at the axis position of the q-axis, adopts an arc-shaped magnetic barrier and is uniformly arranged in the arc-shaped slot corresponding to the edge of the rotor core (4) with the opening side outward, each of the second magnetic barriers (6) is located at the axis position of the d-axis, adopts a strip-shaped magnetic barrier and is uniformly arranged along the radial direction at the edge position inside the rotor core (4), each of the third magnetic barriers is composed of two magnetic barriers (7), the two magnetic barriers (7) are symmetrically arranged on both sides of the axis of the d-axis in a triangular shape and are uniformly arranged at the position adjacent to the main shaft inside the rotor core (4), the number of the direct axis bypass magnetic bridges (8) is 2p, the direct axis bypass magnetic bridge (8) is arc-shaped and is arranged at the corresponding first magnetic barrier (5) one by one, the permanent magnet group includes permanent magnets one (9), permanent magnets two (10) and permanent magnets three (11), each of which is 4p, two permanent magnets one (9) in each group are symmetrically arranged on both sides of the axis of the d-axis in a V shape and are embedded and fixed at the middle position inside the rotor core (4), the inner side ends of the two permanent magnets one (9) in each group are respectively connected with the two magnetic barriers (7) of the corresponding third magnetic barrier, the outer side ends of the two permanent magnets one (9) in each group are respectively embedded and fixed with the permanent magnets two (10) along the axis direction, the cross-sectional area of the permanent magnets two (10) is smaller than that of the permanent magnets one (9), the permanent magnets three (11) are arranged in a vertical line on both sides of the axis of the d-axis in a group of two and are embedded and fixed at the bottom end of the corresponding second magnetic barrier (6) inside the rotor core (4), wherein p is the pole pair number of the motor.

2. The inverse salient pole permanent magnet synchronous motor decoupling the magnetic circuit of the magnetic pole and the main magnetic circuit of the armature according to claim 1, characterized in that: The number of the stator wire slots (2) is a multiple of 3.

3. The inverse salient pole permanent magnet synchronous motor decoupling the magnetic circuit of the magnetic pole and the main magnetic circuit of the armature according to claim 1, characterized in that: The material of the permanent magnets one (9) is ferrite, and the materials of the permanent magnets two (10) and the permanent magnets three (11) are neodymium iron boron.

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