A self-starting synchronous reluctance motor rotor and a self-starting synchronous reluctance motor
By optimizing the design of the rotor core and stator slot in a self-starting synchronous reluctance motor, the problems of torque pulsation and vibration noise are solved, and more efficient magnetic field alternation and motor performance improvement are achieved.
Patent Information
- Application Number
- CN202210092248.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-01-26
- Publication Date
- 2024-12-27
- Estimated Expiration
- 2042-01-26
AI Technical Summary
The existing self-starting synchronous reluctance motor has the problem of large torque pulsation, resulting in high vibration noise.
By designing that the maximum common divisor of the magnetic layer and stator groove of the rotor core is not equal to the number of motor poles or pole pairs, combined with the matching combination of the number of magnetic layers and the number of stator grooves, the width of the magnetic pole arc and stator teeth is limited. Form effective magnetic field alternation to reduce torque pulsation.
It effectively reduces the harmonic vibration amplitude, improves the motor frequency and efficiency, reduces vibration noise, and improves the motor output efficiency.
Smart Images
Figure CN114598058B_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the technical field of motors, and in particular to a self-starting synchronous reluctance motor rotor and a self-starting synchronous reluctance motor. Background Art
[0002] The self-starting synchronous reluctance motor has the characteristics of both asynchronous motor and synchronous reluctance motor, and has the following basic features:
[0003] Air slots are opened in the rotor along the axial direction. The air slots are called magnetic barrier slots. The core part formed between every two layers of magnetic barrier slots is called magnetic conductive channel.
[0004] The magnetic barrier slot is fully or partially filled with conductive non-magnetic material (such as aluminum), which is called a conductive bar;
[0005] There are end rings at both ends of the rotor axially. The material of the end rings is the same as that of the guide bars. The end rings at both ends of the rotor are connected to all or part of the guide bars in the rotor slots to form a short circuit.
[0006] Each pole of the rotor forms two symmetric axes, the D axis and the Q axis. The axis approximately parallel to the magnetic channel is called the D axis, and the axis approximately perpendicular to the magnetic channel is called the Q axis.
[0007] The self-starting synchronous reluctance motor combines the advantages of asynchronous motors, which can be started directly without a frequency converter, have no magnetic steel on the rotor, and have high reliability, as well as the advantages of synchronous reluctance motors, which have stable operation in synchronization, high efficiency, and high power density. In the industrial field, it is a breakthrough in the IE4 energy efficiency of fixed-frequency motors, while also having lower costs.
[0008] Vibration and noise are important indicators of industrial motors. Torque pulsation is an important cause of vibration and noise. How to effectively reduce torque pulsation is a difficult problem that the industry generally pays attention to.
[0009] Since the self-starting synchronous reluctance motor in the prior art has technical problems such as large torque pulsation, resulting in large vibration and noise, the present invention studies and designs a self-starting synchronous reluctance motor rotor and a self-starting synchronous reluctance motor.
[0010] Public Content
[0011] Therefore, the technical problem to be solved by the present disclosure is to overcome the defects of the self-starting synchronous reluctance motor in the prior art, that is, large torque pulsation, resulting in large vibration and noise, thereby providing a self-starting synchronous reluctance motor rotor and a self-starting synchronous reluctance motor.
[0012] In order to solve the above problems, the present disclosure provides a self-starting synchronous reluctance motor rotor, which includes:
[0013] A rotor core, wherein air slots are provided on the rotor core to form a magnetic barrier layer, and the rotor core comprises a D axis and a Q axis; a portion between two adjacent magnetic barrier layers is a magnetic conductive channel layer;
[0014] The greatest common divisor of the number of stator slots and the number of layers of the magnetic barrier layer is not equal to the number of poles or pole pairs, that is, GCD(N S , N B )≠(p, 2p); where N S is the number of stator slots, N B is the number of magnetic barrier layers of the rotor under each pole, and p is the number of pole pairs of the motor rotor.
[0015] In some embodiments, the number of stator slots is an even number, and the number of magnetic barrier layers of the rotor is an odd number; and / or the greatest common divisor of the number of stator slots and the number of magnetic barrier layers is 1, that is, GCD(N S , N B )=1.
[0016] In some embodiments, the magnetic barrier pole arc Rn of the nth magnetic barrier layer parallel to the D axis is the arc length of the midpoint of the arc line of the two layers of magnetic conductive channels adjacent to the upper nth magnetic barrier layer parallel to the D axis on the outer circle of the rotor, and the arc lengths of the magnetic barrier pole arcs of each layer from the position of the D axis to the direction away from the D axis are R1 to R NB ; 1≤n≤NB.
[0017] In some embodiments, the magnetic barrier pole arc R1 of the first magnetic barrier layer is ≤30 mm, the first magnetic barrier layer is the magnetic barrier layer closest to the D axis, and the magnetic barrier pole arcs R1 of the second to the second to last magnetic barrier layers are ≤30 mm. n ≤20mm, the magnetic barrier pole arc R of the outermost magnetic barrier layer NB ≤50mm, where the outermost magnetic barrier layer is the magnetic barrier layer farthest from the D axis.
[0018] In some embodiments, the rotor core is formed by axially stacking rotor laminations.
[0019] In some embodiments, the magnetic barrier layer is divided into multiple layers along the Q axis, and the magnetic barrier layer close to the radial outer circle relative to the rotor axis is a filling groove; the filling groove is filled with conductive but non-magnetic material, namely, conductive bars.
[0020] In some embodiments, the guide bar is a cast aluminum structure and is formed in the filling groove by casting.
[0021] In some embodiments, end rings made of conductive and non-magnetic materials are placed at both axial ends of the rotor core, and all or part of the conductive bars are short-circuited together through the end rings to form a loop.
[0022] The present disclosure also provides a self-starting synchronous reluctance motor, which comprises the self-starting synchronous reluctance motor rotor as described in any of the preceding items.
[0023] In some embodiments, the stator includes stator teeth, a stator slot is provided between two adjacent stator teeth, and the circumferential width of the stator teeth is W. T , and there is W T ≤15mm.
[0024] A self-starting synchronous reluctance motor rotor and a self-starting synchronous reluctance motor provided by the present disclosure have the following beneficial effects:
[0025] 1. The present invention makes the greatest common divisor of the number of stator slots and the number of layers of the magnetic barrier layer not equal to the number of poles or pole pairs, that is, GCD (N S , N B )≠(p, 2p), by setting the greatest common divisor to be unequal to the number of poles or the number of pole pairs, so that the greatest common divisor is reduced, the number of times the rotor overlaps with the stator at the same position during one rotation is lower, and one overlap is a waveform, which effectively increases the frequency and effectively reduces the harmonic vibration amplitude, thereby effectively reducing the torque pulsation and improving the motor efficiency; further, the number of stator slots is an even number, and the number of magnetic barrier layers of the rotor is an odd number; and / or, the greatest common divisor of the number of stator slots and the number of magnetic barrier layers is 1, that is, GCD(N S , N B )=1, which can further reduce the greatest common divisor, thereby further maximizing the frequency, reducing the harmonic amplitude, increasing the fundamental amplitude, reducing the torque ripple, and improving the motor output efficiency;
[0026] 2. The present disclosure also sets the magnetic barrier pole arc R1 of the first magnetic barrier layer to ≤30 mm, and the magnetic barrier pole arc R1 of the second to the second to last magnetic barrier layer to ≤30 mm. n ≤20mm, the magnetic barrier pole arc R of the outermost magnetic barrier layer NB ≤50mm, which can effectively restrict the maximum width of the magnetic barrier layer, ensure a large number of magnetic barrier layers, and help reduce torque pulsation; the present disclosure also sets the circumferential width of the stator teeth to WT, and has W T ≤15mm, which can effectively constrain the maximum width of the stator teeth. The number of stator and rotor magnetic field alternations increases, that is, the frequency becomes higher. As the frequency increases, the amplitude will decrease, thereby reducing pulsation. At the same time, when the outer diameter of the motor is large, ensuring a large number of stator slots is further beneficial to reducing torque pulsation. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Figure 1 A schematic diagram of a magnetic barrier and a magnetic conductive channel of a rotor of a self-starting synchronous reluctance motor disclosed in the present invention;
[0028] Figure 2It is a schematic structural diagram of each magnetic barrier pole arc of the rotor of the self-starting synchronous reluctance motor disclosed in the present invention;
[0029] Figure 3 It is a structural schematic diagram of stator slots and stator teeth of the self-starting synchronous reluctance motor disclosed in the present invention;
[0030] Figure 4 A bar graph comparing the motor disclosed herein and a conventional motor in terms of harmonics and fundamental waves;
[0031] Figure 5 A comparison curve diagram of the load and efficiency of the motor disclosed herein and a conventional motor;
[0032] Figure 6 A comparison curve diagram of torque ripple between the motor disclosed herein and a conventional motor;
[0033] Figure 7 It is a schematic diagram of the structure of the guide bar and the end ring of the present invention.
[0034] The reference numerals are as follows:
[0035] 1. Rotor core; 10. Shaft hole; 2. Magnetic barrier layer; 3. Magnetic channel layer; 4. Conductor bar; 5. End ring; 6. Stator; 61. Stator teeth; 62. Stator slots. DETAILED DESCRIPTION
[0036] like Figure 1-7 As shown, the present disclosure provides a self-starting synchronous reluctance motor rotor, which includes:
[0037] A rotor core 1, wherein air slots are provided on the rotor core 1 to form a magnetic barrier layer 2. According to the shape of the magnetic barrier layer 2, the rotor core 1 includes a D axis and a Q axis. Two adjacent rotor poles are symmetrical about the D axis, and the same pole is symmetrical about the Q axis. The portion between two adjacent layers of the magnetic barrier layer 2 is a magnetic conductive channel layer 3.
[0038] The greatest common divisor of the number of stator slots and the number of layers of the magnetic barrier layer is not equal to the number of poles or pole pairs, that is, GCD(N S , N B )≠(p, 2p); where N S is the number of stator slots, N B is the number of magnetic barrier layers of the rotor under each pole, and p is the number of pole pairs of the motor rotor. A shaft hole 10 is provided on the radial inner periphery of the rotor core.
[0039] The present invention makes the greatest common divisor of the number of stator slots and the number of layers of the magnetic barrier layer not equal to the number of poles or the number of pole pairs, that is, GCD (N S , N B)≠(p, 2p), by setting the greatest common divisor to be unequal to the number of poles or pole pairs, the greatest common divisor is reduced, the rotor rotates one circle and overlaps with the stator at the same position, the overlap is one waveform, the frequency is effectively increased, the amplitude of harmonic vibration is effectively reduced, and thus the torque pulsation is effectively reduced and the motor efficiency is improved. Harmonics are interferences and also consume inputs. Only the fundamental wave is effective. The fundamental wave + harmonics together constitute the input source. The more harmonics, the less fundamental waves, and the lower the efficiency. Harmonics are noise sources. All noise problems can be attributed to harmonics. Reducing the amplitude of harmonics can reduce noise and improve motor efficiency.
[0040] In some embodiments, the number of stator slots is an even number, and the number of magnetic barrier layers of the rotor is an odd number; and / or the greatest common divisor of the number of stator slots and the number of magnetic barrier layers is 1, that is, GCD(N S , N B )=1. Further, the number of stator slots is an even number, and the number of magnetic barrier layers of the rotor is an odd number; and / or, the greatest common divisor of the number of stator slots and the number of magnetic barrier layers is 1, that is, GCD(N S , N B )=1, which can further reduce the greatest common divisor, thereby further maximizing the frequency, reducing the harmonic amplitude, increasing the fundamental amplitude, reducing the torque pulsation, and improving the motor output efficiency.
[0041] 1. The present invention adopts a matching combination of the number of magnetic barrier layers and the number of stator slots of the motor, and the greatest common divisor of the number of magnetic barrier layers and the number of stator slots is not equal to the number of motor poles or pole pairs. Preferably, the greatest common divisor of the number of magnetic barrier layers and the number of stator slots is 1, which can effectively reduce torque pulsation, reduce noise, and improve motor efficiency;
[0042] 2. The magnetic barrier pole arc is the length of the arc drawn by the midpoints of the two layers of magnetic conductive channels adjacent to the magnetic barrier layer on the outer circle of the rotor; the arc length of the magnetic barrier pole arc of each layer and the stator tooth width of the motor rotor disclosed in the present invention meet the constraint conditions, and the arc length of the magnetic barrier pole arc and the stator tooth width of the first layer, the middle layer and the last layer are constrained respectively, which can further reduce torque pulsation and reduce noise.
[0043] The torque pulsation of the motor that meets the constraint relationship between the number of rotor magnetic barrier layers and the number of stator slots and the constraint relationship between the magnetic barrier pole arc and the stator tooth width described in the present invention is significantly reduced.
[0044] In some embodiments, the magnetic barrier pole arc Rn of the nth magnetic barrier layer parallel to the D axis is the arc length of the midpoint of the arc line of two layers of magnetic conductive channels adjacent to the nth magnetic barrier layer parallel to the D axis on the outer circle of the rotor, and the arc lengths of each layer of magnetic barrier pole arc from the position of the D axis to the direction away from the D axis are R1~RNB respectively; 1≤n≤NB.
[0045] 1. Each layer of magnetic barrier starts from the position parallel to the D axis, passes through the Q axis and passes through the inside of the rotor, and ends at the D axis on the other side symmetrical to the starting point;
[0046] 2. The magnetic barrier pole arc is the length of the arc drawn by the two intersection points of the midpoints of the two magnetic conductive channels adjacent to the magnetic barrier and the outer circle of the rotor on the outer circle of the rotor;
[0047] 3. The magnetic barrier layer is defined as 1~NB from the inner circle to the outer circle of the rotor, and the corresponding magnetic barrier pole arc is R1~RNB.
[0048] In some embodiments, the magnetic barrier pole arc R1 of the first magnetic barrier layer is ≤30 mm, the first magnetic barrier layer is the magnetic barrier layer closest to the D axis, and the magnetic barrier pole arcs R1 of the second to the second to last magnetic barrier layers are ≤30 mm. n ≤20mm, the magnetic barrier pole arc R of the outermost magnetic barrier layer NB ≤50mm, where the outermost magnetic barrier layer is the magnetic barrier layer farthest from the D axis.
[0049] The present invention also sets the magnetic barrier pole arc R1 of the first magnetic barrier layer to be less than 30 mm, and the magnetic barrier pole arc R1 of the second to the second to last magnetic barrier layers to be less than 30 mm. n ≤20mm, the magnetic barrier pole arc R of the outermost magnetic barrier layer NB ≤50mm, which can effectively restrict the maximum width of the magnetic barrier layer and ensure a large number of magnetic barrier layers, which is beneficial to reducing torque pulsation.
[0050] Keywords:
[0051] 1. Rotor magnetic barrier: the layers of air slots opened on the rotor;
[0052] 2. Rotor magnetic channel: The part between the air slots of each layer of the rotor is called the magnetic channel layer;
[0053] 3. Magnetic barrier pole arc: The length of the arc drawn by the midpoints of the two layers of magnetic conductive channels adjacent to the magnetic barrier layer on the outer circle of the rotor.
[0054] In some embodiments, the rotor core 1 is formed by axially stacking rotor laminations; the number of groups of the magnetic barrier layers 2 is the number of poles of the motor rotor. There are multiple magnetic barrier layers under each pole, and each pole has a magnetic barrier layer group. The number of times the magnetic barrier layer group is repeated is the number of rotor poles, that is, the number of magnetic barrier layer groups. For example, the attached figure is a 2-pole rotor, including a total of 2 poles above the D axis and below the D axis.
[0055] In some embodiments, the magnetic barrier layer 2 is divided into multiple layers along the Q axis, and the magnetic barrier layer 2 close to the radial outer circle relative to the rotor axis is a filling groove; the filling groove is filled with a conductive but non-magnetic material, namely, a conductive bar 4.
[0056] In some embodiments, the guide bar 4 is a cast aluminum structure and is formed in the filling groove by casting.
[0057] The motor of the present invention can be made of cast aluminum in all magnetic barrier slots or in part of the magnetic barrier slots;
[0058] The motor end ring of the present invention may be in a circular ring or other regular or irregular shapes.
[0059] In some embodiments, end rings 5 made of conductive and non-magnetic materials are placed at both axial ends of the rotor core 1, and all or part of the conductive bars 4 are short-circuited together through the end rings 5 to form a loop.
[0060] The present disclosure also provides a self-starting synchronous reluctance motor, which includes the self-starting synchronous reluctance motor rotor as described in any of the preceding items, and also includes a stator 6.
[0061] In some embodiments, the stator 6 includes stator teeth 61, a stator slot 62 is provided between two adjacent stator teeth 61, and the circumferential width of the stator teeth 61 is W. T , and there is W T ≤15mm. The present disclosure also sets the circumferential width of the stator teeth to WT, and W T ≤15mm, which can effectively constrain the maximum width of the stator teeth. At the same time, when the outer diameter of the motor is large, it ensures a large number of stator slots, which is further beneficial to reducing torque pulsation.
[0062] The motor of the present invention comprises a rotor core 1 formed by axially stacking rotor punchings;
[0063] The rotor core is provided with multiple groups of identical air slots, and the number of air slot groups is the number of rotor poles;
[0064] The air slots are divided into multiple layers along the Q axis, and the air slots on the outer side of the rotor are filled slots;
[0065] Part or all of the air slots are filled with conductive but non-magnetic material, called conductive bars 4;
[0066] End rings 5 made of conductive but non-magnetic material are placed at both ends of the rotor;
[0067] All or part of the conductor bars are short-circuited together through end rings to form a loop;
[0068] The air slots are divided into multiple layers along the Q axis. According to the shape of the air slots, the radial direction parallel to the air slots is called the D axis, and the radial direction perpendicular to the air slots is called the Q axis;
[0069] Each layer of air slots on the rotor is called a magnetic barrier layer 2, and the portion between two adjacent layers of air slots is called a magnetic conductive channel layer 3;
[0070] The number of stator slots is N S , the number of rotor magnetic barriers under each pole is N B .
[0071] The above is only a preferred embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present disclosure shall be included in the protection scope of the present disclosure. The above is only a preferred implementation of the present disclosure. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present disclosure, and these improvements and variations should also be regarded as the protection scope of the present disclosure.
Claims
1. A self-starting synchronous reluctance motor rotor, characterized in that: include: A rotor core (1), wherein air slots are provided on the rotor core (1) to form a magnetic barrier layer (2), and the rotor core (1) comprises a D axis and a Q axis; a portion between two adjacent layers of the magnetic barrier layer (2) is a magnetic conductive channel layer (3); And the greatest common divisor of the number of stator slots and the number of layers of the magnetic barrier layer is not equal to the number of poles or pole pairs, that is, GCD (N s , N B )≠(p,2p); where N S is the number of stator slots, N B is the number of magnetic barrier layers of the rotor under each pole, and p is the number of pole pairs of the motor rotor; The magnetic barrier pole arc R of the nth magnetic barrier layer parallel to the D axis n is the arc length of the midpoint of the arc line of the two layers of magnetic conductive channels adjacent to the nth magnetic barrier layer parallel to the D axis on the outer circle of the rotor, and the arc lengths of the magnetic barrier pole arcs of each layer from the position of the D axis to the direction away from the D axis are R1~R NB ; 1≤n≤N B ; The magnetic barrier pole arc R1 of the first magnetic barrier layer is ≤30mm. The first magnetic barrier layer is the magnetic barrier layer closest to the D axis. The magnetic barrier pole arcs R1 of the second to the second to last magnetic barrier layers are n ≤20mm, the magnetic barrier pole arc R of the outermost magnetic barrier layer NB ≤50mm, where the outermost magnetic barrier layer is the magnetic barrier layer farthest from the D axis.
2. The self-starting synchronous reluctance motor rotor according to claim 1, characterized in that: The number of stator slots is an even number, and the number of magnetic barrier layers of the rotor is an odd number; and / or the greatest common divisor of the number of stator slots and the number of magnetic barrier layers is 1, that is, GCD (N s , N B )=1.
3. The self-starting synchronous reluctance motor rotor according to any one of claims 1-2, characterized in that: The rotor core (1) is formed by axially stacking rotor punchings.
4. The self-starting synchronous reluctance motor rotor according to any one of claims 1-2, characterized in that: The magnetic barrier layer (2) is divided into multiple layers along the Q axis, and the magnetic barrier layer (2) close to the radial outer circle relative to the axis of the rotor is a filling groove; the filling groove is filled with a conductive but non-magnetic material, namely a conductive bar (4).
5. The self-starting synchronous reluctance motor rotor according to claim 4, characterized in that: The guide bar (4) is a cast aluminum structure and is formed in the filling groove by casting.
6. The self-starting synchronous reluctance motor rotor according to claim 4, characterized in that: End rings (5) made of conductive but non-magnetic material are placed at both axial ends of the rotor core (1), and all or part of the conductive bars (4) are short-circuited together through the end rings (5) to form a loop.
7. A self-starting synchronous reluctance motor, characterized in that: The self-starting synchronous reluctance motor comprises a rotor as claimed in any one of claims 1 to 6, and further comprises a stator (6).
8. The self-starting synchronous reluctance motor according to claim 7, characterized in that: The stator (6) comprises stator teeth (61), a stator slot (62) is provided between two adjacent stator teeth (61), and the circumferential width of the stator teeth (61) is W. T , and there is W T ≤15mm.