Demagnetization Resistance Structure of Bipolar Asynchronous Starting Hybrid Permanent Magnet Synchronous Motor

Abstract

The present invention relates to an anti-demagnetization structure of a two-pole asynchronous starting hybrid permanent magnet synchronous motor, which comprises a stator structure and a rotor structure. The stator structure includes a stator core arranged in a cylindrical ring shape, and stator slots evenly recessed on the inner circumference of the stator core, and the stator slots extend axially along the cylindrical inner wall surface of the stator core; the rotor structure includes a cylindrical rotor core sleeved in the central hole of the stator core, rotor slot punching sheets evenly inserted on the rotor core and protruding on the top and bottom surfaces of the outer circumference of the rotor core, a plurality of magnetic isolation slots opened on the rotor core and respectively connected to the rotor slot punching sheets, and a plurality of crescent-shaped magnet slots arranged on the top and bottom surfaces of the rotor core and along the circumference of the rotor core, and the plurality of magnet slots are arranged inside the rotor slot punching sheets; the air-gap magnetic density waveform of the present invention is more sinusoidal, the distortion rate is lower, the anti-demagnetization ability is better, and the steady-state performance of the motor is better.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and particularly relates to an anti-demagnetization structure for a two-pole asynchronous starting hybrid permanent magnet synchronous motor. Background Art

[0002] Energy conservation and emission reduction is an inescapable topic in today's world, which affects the living environment of mankind and the development of the world economy. As an important industrial field for energy conservation and emission reduction, improving the energy efficiency level of electric motors is of great significance for China's energy conservation, environmental protection, and promoting economic development.

[0003] Traditional asynchronous motors have low power factors and efficiencies because they do not have permanent magnet excitation, resulting in a large waste of electrical energy. For traditional asynchronous starting permanent magnet synchronous motors, the rotor magnet slots are single-layer neodymium iron boron materials with U-shaped or W-shaped grooves. Although the power factor and efficiency of the motor are improved, the cost is increased because the neodymium iron boron material is expensive; and its magnetic performance is strong, the generating braking torque is too large, which is not conducive to starting; and the air-gap magnetic density harmonics are large, which is not conducive to steady-state operation. At the same time, during the starting process of the permanent magnet motor, the magnetic field in the permanent magnet of the motor is mainly composed of two parts, the armature reaction magnetic field and the magnetic field of the permanent magnet itself. The armature reaction magnetic field may be a demagnetizing magnetic field at some positions of the rotor. In this way, due to the large starting current generated during the frequent starting and stopping of the motor, it may cause large-area demagnetization of the permanent magnet in the motor, resulting in a decline in the performance of the motor and even abnormal operation. Summary of the Invention

[0004] The embodiment of the present invention provides an anti-demagnetization structure for a two-pole asynchronous starting hybrid permanent magnet synchronous motor, with a more sinusoidal air-gap magnetic density waveform, lower distortion rate, better anti-demagnetization ability, and better steady-state performance of the motor.

[0005] On the one hand, the embodiment of the present invention provides an anti-demagnetization structure for a two-pole asynchronous starting hybrid permanent magnet synchronous motor, including a stator structure and a rotor structure. The stator structure includes a stator core arranged in a cylindrical ring shape, and stator slots evenly recessed on the inner circumference of the stator core, and the stator slots extend axially along the inner wall surface of the cylindrical stator core; the rotor structure includes a cylindrical rotor core sleeved in the central hole of the stator core, rotor slot punching sheets evenly inserted on the rotor core and protruding on the top and bottom surfaces of the outer circumference of the rotor core, a plurality of magnetic isolation slots opened on the rotor core and respectively connected to the rotor slot punching sheets, and a plurality of crescent-shaped magnet slots arranged on the top and bottom surfaces of the rotor core and along the circumference of the rotor core, and the plurality of magnet slots are arranged inside the rotor slot punching sheets.

[0006] In some embodiments, the plurality of magnet slots are arranged in multiple layers in a ring shape with the center of the rotor core as the center on the rotor core.

[0007] In some embodiments, the outer magnetic steel groove is a bonded neodymium iron boron magnetic steel groove, and the inner magnetic steel groove is a ferrite magnetic steel groove.

[0008] In some embodiments, the distance from the outer circumference of the outer magnetic steel groove to the inner side of the rotor slot punching is 5 mm, the distance from the outer circumference of the inner magnetic steel groove to the inner circumference of the outer magnetic steel groove is 5 mm, the outer circumference radius of the outer magnetic steel groove is 1.3 times the radius of the rotor core, and the outer circumference radius of the inner magnetic steel groove is 1.14 times the outer circumference radius of the outer magnetic steel groove.

[0009] In some embodiments, the rotor slot punchings connected to the magnetic isolation groove and the outer sides of two adjacent rotor slot punchings connected to the magnetic isolation groove are both of an open slot structure, and the open slot structure extends to the outer circumference of the rotor core.

[0010] In some embodiments, the width value of the magnetic isolation groove is 3 / 5 times the length value of the magnetic isolation groove.

[0011] In some embodiments, the length value of the rotor slot punching is 1.5 times the width value of the rotor slot punching; the width value of the open slot structure is 0.8 times the length value of the open slot structure.

[0012] In some embodiments, the stator slot is arranged as a pear-shaped slot, the slot mouth width value of the stator slot is 3.8 mm, the slot mouth length value of the stator slot is 0.8 mm, the slot bottom length value of the stator slot is 13.44 mm, the slot bottom width value of the stator slot is 9.4 mm, the slot shoulder width value of the stator slot is 6.9 mm, and the slot shoulder length value of the stator slot is 0.98 mm.

[0013] In some embodiments, annular rotor end rings are covered on both the top and bottom ends of the rotor slot punching.

[0014] In some embodiments, the rotor slot punching and the rotor end ring are connected by welding.

[0015] The beneficial effects brought by the technical solution provided by the present invention include: For the demagnetization-resistant structure of the two-pole asynchronous starting hybrid permanent magnet synchronous motor provided by the present invention, compared with the waveform of the traditional asynchronous starting permanent magnet synchronous motor, the air-gap magnetic density waveform in this embodiment is more sinusoidal and has a lower distortion rate, indicating that harmonics are effectively suppressed, and the harmonic content in the air-gap magnetic density can be better reduced. Therefore, the steady-state performance of the motor is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0017] Figure 1 Schematic three-dimensional structure diagram of an embodiment of the present invention;

[0018] Figure 2 Schematic three-dimensional structure diagram of the rotor structure of an embodiment of the present invention;

[0019] Figure 3 Waveform comparison diagram of an embodiment of the present invention and a traditional asynchronous starting permanent magnet synchronous motor;

[0020] Figure 4 Schematic plan structure diagram of an embodiment of the present invention;

[0021] Figure 5 Schematic plan annotation diagram of a partial rotor slot punching sheet and a partial magnet slot of an embodiment of the present invention;

[0022] Figure 6 Schematic plan annotation diagram of a magnetic isolation slot and a rotor slot punching sheet of an embodiment of the present invention;

[0023] Figure 7 Schematic plan annotation diagram of a stator slot of an embodiment of the present invention.

[0024] In the figure: 10, stator structure; 100, stator core; 101, stator slot; 20, rotor structure; 200, rotor core; 201, rotor slot punching sheet; 202, magnetic isolation slot; 203, magnet slot; 204, rotor end ring. Detailed implementation manners

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0026] See Figure 1 、 Figure 2As shown in the figure; an embodiment of the present invention provides an anti-demagnetization structure for a two-pole asynchronous starting hybrid permanent magnet synchronous motor, which includes a stator structure 10 and a rotor structure 20. The stator structure 10 includes a stator core 100 arranged in a cylindrical ring shape, and stator slots 101 uniformly recessed on the inner circumference of the stator core 100. The stator slots 101 extend axially along the cylindrical inner wall surface of the stator core 100. The rotor structure 20 includes a cylindrical rotor core 200 sleeved in the central hole of the stator core 100, rotor slot punching sheets 201 uniformly inserted on the rotor core 200 and protruding on the top and bottom surfaces of the outer circumference of the rotor core 200, a plurality of magnetic isolation slots 202 opened on the rotor core 200 and respectively connected to the rotor slot punching sheets 201, and a plurality of crescent-shaped magnet slots 203 arranged on the top and bottom surfaces of the rotor core 200 and along the circumference of the rotor core 200. The plurality of magnet slots 203 are arranged inside the rotor slot punching sheets 201.

[0027] It should be noted that by uniformly inserting the rotor slot punching sheets 201 on the rotor core 200 and protruding on the top and bottom surfaces of the outer circumference of the rotor core 200, and at the same time, the rotor slot punching sheets 201 are selected as resistance bars, it is time-saving and convenient compared with the cast aluminum structure and is safer; at the same time, referring to Figure 3 As shown in the figure, by comparing the waveform (left figure) of the anti-demagnetization structure of the two-pole asynchronous starting hybrid permanent magnet synchronous motor provided by this embodiment with the waveform (right figure) of the traditional asynchronous starting permanent magnet synchronous motor, the air-gap magnetic density waveform of this embodiment is more sinusoidal and has a lower distortion rate, indicating that the harmonics are effectively suppressed, and the harmonic content in the air-gap magnetic density can be better reduced. Therefore, the steady-state performance of the motor is better; at the same time, the magnetic performance of the crescent-shaped magnet slots 203 is better than that of the U-shaped structure and the W-shaped structure.

[0028] Optionally, the plurality of magnet slots 203 are arranged on the rotor core 200 in a multi-layer annular shape centered on the center of the rotor core 200; by adopting the multi-layer crescent-shaped magnet slots 203, it is beneficial to increase the reluctance torque and improve the torque performance of the motor.

[0029] Optionally, the outer-layer magnet slots 203 are set as bonded neodymium iron boron magnet slots, and the inner-layer magnet slots 203 are set as ferrite magnet slots; by adopting the above-mentioned hybrid excitation structure, compared with the pure sintered neodymium iron boron magnet, it can not only reduce the cost of the magnet material, but also improve the anti-demagnetization ability of the motor. At the same time, it can also play a role in enhancing the air-gap magnetic density, reducing the current, improving the power factor and efficiency, and achieving the effect of saving electric energy.

[0030] At the same time, referring to Figure 5As shown, in the embodiment of the present invention, in order to better improve the anti-demagnetization ability of the motor and make the air-gap magnetic density waveform more sinusoidal; the distance D1 between the outer circumference of the outer magnetic steel groove 203 and the inner side of the rotor groove punching sheet 201 is 5 mm, the distance D2 between the outer circumference of the inner magnetic steel groove 203 and the inner circumference of the outer magnetic steel groove 203 is 5 mm, the outer circumference radius R1 of the outer magnetic steel groove 203 is 1.3 times the radius R0 of the rotor core 200, and the outer circumference radius R2 of the inner magnetic steel groove 203 is 1.14 times the outer circumference radius R1 of the outer magnetic steel groove 203.

[0031] See also Figure 4 As shown, in the embodiment of the present invention, the outer sides of the rotor groove punching sheet 201 connected to the magnetic isolation groove 202 and the adjacent two rotor groove punching sheets 201 of the rotor groove punching sheet 201 connected to the magnetic isolation groove 202 are all in an open groove structure, and the open groove structure extends to the outer circumference of the rotor core 200.

[0032] In this embodiment, the number of stator slots 101 is 35 slots, the number of rotor groove punching sheets 21 is 28 slots, and the number of magnetic isolation grooves 202 is 2 slots. By making the outer sides of the rotor groove punching sheet 201 connected to the magnetic isolation groove 202 and the adjacent two rotor groove punching sheets 201 of the rotor groove punching sheet 201 connected to the magnetic isolation groove 202 all in an open groove structure, there are 6 magnetic isolation grooves 202 in the open groove structure and 22 slots in the closed groove structure. Through the above design, the leakage reactance of the rotor structure 20 can be increased, the starting current can be reduced, and the anti-demagnetization ability can be improved at the same time. Therefore, the resistance of the rotor structure 20 can be adjusted accordingly, so that the motor can start smoothly and be efficiently pulled into synchronization.

[0033] See also Figure 6 As shown, in the embodiment of the present invention, in order to better improve the anti-demagnetization ability, the dimensions of the magnetic isolation groove 202 and the rotor groove punching sheet 201 are correspondingly limited; specifically, the width value c of the magnetic isolation groove 202 is 3 / 5 times the length value d of the magnetic isolation groove 202; optionally, the length value f of the rotor groove punching sheet 201 is 1.5 times the width value e of the rotor groove punching sheet 201; the width value b of the open groove structure is 0.8 times the length value a of the open groove structure.

[0034] See also Figure 6As shown, in the embodiment of the present invention, in order to make the design of the stator slot 101 more reasonable and also to adapt to the dimensions of the rotor slot punching sheet 201, the dimensions of the stator slot 101 are correspondingly restricted. Specifically, the stator slot 101 is arranged as a pear-shaped slot. The slot opening width value g of the stator slot 101 is 3.8 mm, the slot opening length value h of the stator slot 101 is 0.8 mm, the slot bottom length value i of the stator slot 101 is 13.44 mm, the slot bottom width value j of the stator slot 101 is 9.4 mm, the slot shoulder width value k of the stator slot 101 is 6.9 mm, and the slot shoulder length value m of the stator slot 101 is 0.98 mm.

[0035] Optionally, annular rotor end rings 204 are provided on both the top and bottom of the rotor slot punching sheet 201; optionally, the rotor slot punching sheet 201 and the rotor end rings 204 are connected by welding; by welding the rotor slot punching sheet 201 and the rotor end rings 204 into one body, the starting cage of the motor can be formed, and it can better generate torque by relying on the induced current in the rotor slot punching sheet 201 during starting, so as to realize the asynchronous starting of the permanent magnet motor.

[0036] The demagnetization-resistant structure of the two-pole asynchronous starting hybrid permanent magnet synchronous motor provided by the present invention is compared with the waveform of the traditional asynchronous starting permanent magnet synchronous motor. The air-gap magnetic density waveform in this embodiment is more sinusoidal and has a lower distortion rate, indicating that harmonics are effectively suppressed, and the harmonic content in the air-gap magnetic density can be better reduced. Therefore, the steady-state performance of the motor is better. At the same time, by adopting the multi-layer crescent-shaped magnet slots 203, it is beneficial to increase the reluctance torque and improve the torque performance of the motor. At the same time, the outer magnet slot 203 is set as an adhesive neodymium iron boron magnet slot, and the inner magnet slot 203 is set as a ferrite magnet slot. Compared with the pure sintered neodymium iron boron magnet, it can not only reduce the cost of the magnet material, but also improve the demagnetization-resistant ability of the motor, and at the same time can play a role in enhancing the air-gap magnetic density, reducing the current, improving the power factor and efficiency, and achieving the effect of saving electric energy. By making the outer sides of the rotor slot punching sheets 201 connected to the magnetic isolation slots 202 and the adjacent two rotor slot punching sheets 201 connected to the magnetic isolation slots 202 both have an open slot structure, and the remaining magnetic isolation slots 202 have a closed slot structure, the leakage reactance of the rotor structure 20 can be increased, the starting current can be reduced, and the demagnetization-resistant ability can be improved at the same time. Therefore, the resistance of the rotor structure 20 can be adjusted accordingly, so that the motor can start smoothly and be efficiently pulled into synchronization.

[0037] Meanwhile, to better improve the anti-demagnetization ability of the motor and make the air-gap magnetic density waveform more sinusoidal; the distance D1 between the outer circumference of the outer magnetic steel groove 203 and the inner side of the rotor slot punching sheet 201 is 5 mm, the distance D2 between the outer circumference of the inner magnetic steel groove 203 and the inner circumference of the outer magnetic steel groove 203 is 5 mm, the outer circumference radius R1 of the outer magnetic steel groove 203 is 1.3 times the radius R0 of the rotor core 200, and the outer circumference radius R2 of the inner magnetic steel groove 203 is 1.14 times the outer circumference radius R1 of the outer magnetic steel groove 203. To better improve the anti-demagnetization ability, the dimensions of the magnetic isolation groove 202 and the rotor slot punching sheet 201 are correspondingly restricted; specifically, the width value c of the magnetic isolation groove 202 is 3 / 5 times the length value d of the magnetic isolation groove 202; optionally, the length value f of the rotor slot punching sheet 201 is 1.5 times the width value e of the rotor slot punching sheet 201; the width value b of the open slot structure is 0.8 times the length value a of the open slot structure. To make the design of the stator slot 101 more reasonable and also to match the dimensions of the rotor slot punching sheet 201, the dimensions of the stator slot 101 are correspondingly restricted. Specifically, the stator slot 101 is arranged as a pear-shaped slot, the slot opening width value g of the stator slot 101 is 3.8 mm, the slot opening length value h of the stator slot 101 is 0.8 mm, the slot bottom length value i of the stator slot 101 is 13.44 mm, the slot bottom width value j of the stator slot 101 is 9.4 mm, the slot shoulder width value k of the stator slot 101 is 6.9 mm, and the slot shoulder length value m of the stator slot 101 is 0.98 mm.

[0038] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by terms such as "one side" and "one end" is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Unless otherwise clearly specified and defined, the terms "set", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] It should be noted that in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", or any other variant thereof, is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0040] The above are only specific embodiments of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An anti-demagnetization structure for a two-pole asynchronous starting hybrid permanent magnet synchronous motor, characterized in that, Comprising: A stator structure (10), including a stator core (100) arranged in a cylindrical ring shape, and stator slots (101) evenly recessed on the inner circumference of the stator core (100), the stator slots (101) extending axially along the cylindrical inner wall surface of the stator core (100); A rotor structure (20), including a cylindrical rotor core (200) sleeved in the central hole of the stator core (100), rotor slot laminations (201) evenly inserted on the rotor core (200) and protruding on the outer circumferential top and bottom surfaces of the rotor core (200), a plurality of magnetic isolation slots (202) opened on the rotor core (200) and respectively connected to the rotor slot laminations (201), and a plurality of crescent-shaped magnet slots (203) arranged on the top and bottom surfaces of the rotor core (200) and along the circumference of the rotor core (200), the plurality of magnet slots (203) being arranged inside the rotor slot laminations (201); The plurality of magnet slots (203) are arranged on the rotor core (200) in a multi-layer annular shape centered on the center of the rotor core (200); The outer circumference of the outer-layer magnet slot (203) is 5 mm away from the inner side of the rotor slot lamination (201), the outer circumference of the inner-layer magnet slot (203) is 5 mm away from the inner circumference of the outer-layer magnet slot (203), the outer circumference radius of the outer-layer magnet slot (203) is 1.3 times the radius of the rotor core (200), and the outer circumference radius of the inner-layer magnet slot (203) is 1.14 times the outer circumference radius of the outer-layer magnet slot (203); The outer sides of the rotor slot laminations (201) connected to the magnetic isolation slots (202) and the adjacent two rotor slot laminations (201) connected to the magnetic isolation slots (202) are both in an open-slot structure, and the open-slot structure extends to the outer circumference of the rotor core (200); The width value of the magnetic isolation slot (202) is 3 / 5 times the length value of the magnetic isolation slot (202); The stator slot (101) is arranged as a pear-shaped slot; 2. The anti-demagnetization structure of the two-pole asynchronous starting hybrid permanent magnet synchronous motor according to claim 1, wherein The outer-layer magnet slot (203) is set as an adhesive neodymium iron boron magnet slot, and the inner-layer magnet slot (203) is set as a ferrite magnet slot; 3. The anti-demagnetization structure of the two-pole asynchronous starting hybrid permanent magnet synchronous motor according to claim 1, characterized in that, The length value of the rotor slot lamination (201) is 1.5 times the width value of the rotor slot lamination (201); The width value of the open-slot structure is 0.8 times the length value of the open-slot structure; 4. The anti-demagnetization structure of the two-pole asynchronous starting hybrid permanent magnet synchronous motor according to claim 1 or 2, characterized in that, The slot mouth width value of the stator slot (101) is 3.8 mm, the slot mouth length value of the stator slot (101) is 0.8 mm, the slot bottom length value of the stator slot (101) is 13.44 mm, the slot bottom width value of the stator slot (101) is 9.4 mm, the slot shoulder width value of the stator slot (101) is 6.9 mm, and the slot shoulder length value of the stator slot (101) is 0.98 mm; 5. The anti-demagnetization structure of the two-pole asynchronous starting hybrid permanent magnet synchronous motor according to claim 1 or 2, characterized in that, Ring-shaped rotor end rings (204) are respectively covered on the top and bottom ends of the rotor slot laminations (201).

6. The anti-demagnetization structure of the two-pole asynchronous starting hybrid permanent magnet synchronous motor according to claim 5, characterized in that, The rotor slot punching sheet (201) is connected to the rotor end ring (204) by welding.

Images