Stator core, permanent magnet synchronous motor and new energy vehicles

Abstract

The present application provides a stator core, a permanent magnet synchronous motor and a new energy vehicle. The stator core comprises a yoke (1) and a tooth (2), wherein the tooth (2) is located on the inner circumference of the yoke (1), and tooth slots (3) are formed between adjacent tooth portions (2), and the tooth slots (3) are open slots, and the slot width of the tooth slots (3) located on both sides of the q-axis and adjacent to the q-axis is B1, and the slot width of the other tooth slots (3) is B0, and B1<B0. According to the stator core of the present application, the torque pulsation of the permanent magnet synchronous motor can be reduced, so that the NVH performance of the motor is better.

Description

Technical Field

[0001] The present application relates to the technical field of new energy vehicles, and in particular to a stator core, a permanent magnet synchronous motor and a new energy vehicle. Background Art

[0002] As people pay more and more attention to environmental protection and efficient use of energy, the new four modernizations of automobiles have become an industry consensus, and the wave of automobile electrification is becoming more and more surging. As a key link in the energy conversion of new energy vehicles, drive motors have a great impact on new energy vehicles. Permanent magnet synchronous motors are widely used in the field of pure electric or hybrid new energy vehicles because of their advantages such as high torque density, high efficiency, good stability and high reliability.

[0003] With the development of new energy industry technology, the NVH (noise, vibration, and harshness) performance of the drive system has become more important, and the cost pressure of the motor has become greater, so the NVH problem of the motor on the vehicle must be fully considered and solved during motor development. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present application is to provide a stator core, a permanent magnet synchronous motor and a new energy vehicle, which can reduce the torque pulsation of the permanent magnet synchronous motor and make the motor NVH performance better.

[0005] In order to solve the above problems, the present application provides a stator core, including a yoke and a tooth portion, wherein the tooth portion is located on the inner circumference of the yoke, and tooth slots are formed between adjacent tooth portions. The tooth slots are open slots, and the slot width of the tooth slots located on both sides of the q-axis and adjacent to the q-axis is B1, and the slot width of other tooth slots is B0, and B1<B0.

[0006] Preferably, the tooth slots are used to set the winding, the wire diameter of the winding is d, the unit is mm, and B1≥2d.

[0007] Preferably, B1=2d~(2d+0.2)mm.

[0008] Preferably, B1 = 2.0 mm to 2.2 mm.

[0009] Preferably, B1 = 1.9 mm, B0 = 2.5 mm.

[0010] Preferably, the inner diameter of the stator core is Di, B0 / Di=0.0158, B1 / Di=0.012.

[0011] Preferably, the inner diameter of the stator core is Di, the outer diameter is Do, and the split ratio of the stator core is a=Di / Do=0.687.

[0012] Preferably, the slot depth Hs2 of the stator core satisfies Hs2=17 mm to 17.5 mm, wherein the slot depth Hs2 of the stator core is the side length of the slot on both sides of the circumferential direction in the cross section perpendicular to the rotor core.

[0013] Preferably, the tooth width T of the stator core is (0.32-0.34)*Hs2, wherein Hs2 is the tooth slot depth of the stator core.

[0014] Preferably, the circumferential width of the slot bottom of the stator core is Bs2, Bs2 = (0.4-0.42)*Hs2, wherein Hs2 is the slot depth of the stator core.

[0015] According to another aspect of the present application, a permanent magnet synchronous motor is provided, comprising a stator core, wherein the stator core is the stator core described above.

[0016] Preferably, the stator outer diameter Do of the permanent magnet synchronous motor is 230 mm, the stator inner diameter Di=158 mm, and the peak power is 100Kw to 1200Kw.

[0017] According to another aspect of the present application, a new energy vehicle is provided, comprising the above-mentioned stator core or the above-mentioned permanent magnet synchronous motor.

[0018] The stator core provided by the present application includes a yoke and a tooth portion, wherein the tooth portion is located on the inner circumference of the yoke portion, and tooth slots are formed between adjacent tooth portions, and the tooth slots are open slots, and the slot widths of the tooth slots located on both sides of the q-axis and adjacent to the q-axis are B1, and the slot widths of other tooth slots are B0, and B1<B0. The stator core starts with the motor stator size design of the permanent magnet synchronous motor, takes the motor tooth slot torque and torque pulsation as the ultimate optimization goals, optimizes the motor stator size design, and optimizes the tooth slot slot widths on both sides of the q-axis and the tooth slot slot widths at other positions through simulation and combined with production process requirements, to ensure lower motor torque pulsation and better NVH performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic structural diagram of a stator core according to an embodiment of the present application;

[0020] Figure 2 This is a schematic diagram of the size structure of a stator core of an embodiment of the present application;

[0021] Figure 3 This is a diagram of the matching structure of the stator core and the rotor of one embodiment of the present application;

[0022] Figure 4 A schematic diagram of the cogging torque of a permanent magnet synchronous motor of the related art;

[0023] Figure 5A schematic diagram of torque pulsation of a permanent magnet synchronous motor of related technology;

[0024] Figure 6 A schematic diagram of the cogging torque of a permanent magnet synchronous motor using the stator core of an embodiment of the present application;

[0025] Figure 7 Schematic diagram of torque pulsation of a permanent magnet synchronous motor using the stator core of an embodiment of the present application.

[0026] The reference numerals are:

[0027] 1. Yoke; 2. Tooth; 3. Tooth groove. DETAILED DESCRIPTION

[0028] The fundamental cause of torque pulsation in permanent magnet synchronous motors is that the magnetic permeance of the air gap magnetic field trajectory changes, causing the magnetic flux to change, resulting in inconsistent torque at different positions and torque pulsation.

[0029] In order to solve the above problems, refer to Figures 1 to 3 As shown, according to an embodiment of the present application, the stator core includes a yoke portion 1 and a tooth portion 2, wherein the tooth portion 2 is located on the inner circumference of the yoke portion 1, and tooth slots 3 are formed between adjacent tooth portions 2, wherein the tooth slots 3 are open slots, and the slot width of the tooth slots 3 located on both sides of the q-axis and adjacent to the q-axis is B1, and the slot width of the other tooth slots 3 is B0, and B1<B0.

[0030] The stator core starts with the motor stator size design of the permanent magnet synchronous motor, takes the motor cogging torque and torque pulsation as the ultimate optimization goals, optimizes the motor stator size design, and optimizes the cogging slot width on both sides of the q-axis and the cogging slot width at other positions through simulation and combined with production process requirements to ensure lower motor cogging torque and torque pulsation and better NVH performance.

[0031] The tooth slot torque is caused by the change of magnetic permeability, which causes the change of magnetic field energy storage; the rotor q-axis magnetic flux is high, and the corresponding stator tooth magnetic flux is high and the magnetic permeability is small. Since the motor magnetic flux is high in the q-axis direction of the motor, in order to reduce the magnetic flux difference on the entire rotor circumference, it is necessary to optimize the motor magnetic flux distribution, reduce the air gap magnetic field permeability difference, and optimize the motor torque pulsation. In this embodiment, by making the slot width of the adjacent tooth slots 3 on both sides of the q-axis smaller than the slot width of other tooth slots 3, the stator slot width can be reduced, the size of the stator teeth is increased, the tooth permeability related to the stator slot is increased, and the air gap magnetic flux in the q-axis direction of the motor is reduced, so that the air gap magnetic flux distribution on the entire stator core is more uniform, the motor tooth slot torque and torque pulsation are reduced, and the motor NVH performance is optimized.

[0032] In one embodiment, the tooth slots 3 are used to set a winding, the wire diameter of the winding is d, in mm, and B1≥2d.

[0033] In one embodiment, B1=2d~(2d+0.2)mm.

[0034] In one embodiment, B1 = 2.0 mm to 2.2 mm.

[0035] When considering the production process, in order to ensure the production and stator offline efficiency, when the wire diameter used for stator offline is ≥1mm, the slot B1 size can be appropriately enlarged. The ideal design range is 2.0-2.2mm, which can ensure that two wires are offline at the same time, ensuring the motor stator production efficiency, and the motor's slot torque and torque pulsation can also be optimized to a certain extent.

[0036] In one embodiment, B1 = 1.9 mm, B0 = 2.5 mm. In this embodiment, the stator offline efficiency is not considered, only the motor's cogging torque and torque pulsation are considered, so this design can minimize the motor's cogging torque, minimize the torque pulsation, and optimize the NVH.

[0037] In one embodiment, the inner diameter of the stator core is Di, B0 / Di=0.0158, B1 / Di=0.012.

[0038] In this embodiment, the width of each slot of the tooth slot 3 is associated with the inner diameter of the stator core, thereby ensuring that this limitation can be applied to motors of various models and sizes, and improving the applicability of the stator core structure size design.

[0039] In one embodiment, the inner diameter of the stator core is Di, the outer diameter is Do, and the split ratio of the stator core is a=Di / Do=0.687.

[0040] The slot depth Hs2 of the stator core satisfies Hs2=17 mm to 17.5 mm, wherein the slot depth Hs2 of the stator core is the side length of the slots 3 on both sides of the circumference in the cross section perpendicular to the rotor core.

[0041] The tooth width T of the stator core is (0.32-0.34)*Hs2, where Hs2 is the tooth slot depth of the stator core, which can ensure uniform magnetic flux density and permeability of the teeth, small torque pulsation, and avoid magnetic flux saturation.

[0042] During the design process of the stator core of the embodiment of the present application, starting from the stator side, the design is based on the maximum output and the lowest motor material cost, and the stator inner and outer diameter ratio a=0.687 is determined. Then, the motor stator core slot depth size range Hs2=17-17.5mm is determined according to the stator winding lower slot full rate requirement. Then, based on the uniformity of the stator tooth density and the requirement of not exceeding the allowable magnetic density of the material (the magnetic density of the silicon steel sheet used in the stator core of the embodiment of the present application does not exceed 2T); according to the comparison of the finite element analysis results, the stator tooth width T=(5.8±0.2)mm is determined. At this time, the motor tooth magnetic density is evenly distributed, the magnetic permeability consistency is good, and the motor torque pulsation is low.

[0043] In this embodiment, the stator teeth adopt a parallel tooth structure. In a cross section perpendicular to the central axis of the stator core, the length of two parallel sides of the same tooth portion 2 is the tooth slot depth Hs2 of the stator core.

[0044] In this embodiment, the bottom of the tooth slot 3 adopts an arc structure and is connected with the parallel side of the tooth portion 2 to form a line slot structure. At the notch of the stator tooth slot 3, a bevel is used to connect the parallel side and the notch side on the same side to form a closed tooth slot structure.

[0045] In one embodiment, the circumferential width of the slot bottom of the stator core is Bs2, Bs2 = (0.4-0.42) * Hs2, where Hs2 is the slot depth of the stator core. After the stator outer diameter is fixed and the split ratio is determined, the stator tooth yoke size design will have a better range to make the magnetic density values ​​of the teeth and yoke close; this range can be obtained by simulating the size ratio, so that the magnetic density uniformity is better. This limitation can optimize the structure of the stator yoke, thereby effectively solving the problem of uniform magnetic density of the stator yoke. In one embodiment, Bs = 6.8-7.35mm.

[0046] After the stator core is designed in the above manner, the stator slot near the q-axis is reduced, and the magnetic permeability of the magnetic steel at the motor air gap is increased. At this time, the low magnetic permeability at the rotor magnetic bridge can be neutralized, making the magnetic permeability of the entire motor air gap more uniform, thereby achieving the purpose of optimizing the motor torque pulsation.

[0047] See also Figure 4 and Figure 5 As shown, the cogging torque and torque pulsation simulation diagram of the motor when the stator slot size of the motor of the related technology improved based on this application is designed to be 2.5mm, wherein the cogging torque is 3.1156Nm and the torque pulsation is 5.12%.

[0048] See also Figure 6 and Figure 7As shown, a motor adopts the stator core of the embodiment of the present application, adopts stator core tooth slots of unequal width, and simulates the tooth slot torque and torque pulsation diagram when B1=1.9mm and B0=2.5mm. At this time, the motor tooth slot torque is 2.4066Nm and the torque pulsation is 3.6%.

[0049] By comparing the motor of the related art and the motor of the embodiment of the present application, it can be seen that, relative to the motor of the related art, the motor using the stator core of the embodiment of the present application has a 22.7% decrease in cogging torque, a 29.7% decrease in torque pulsation, and a significant improvement in NVH performance.

[0050] In this embodiment, the stator core adopts a parallel teeth structure.

[0051] The motor stator core size design of the embodiment of the present application, that is, the tooth slot depth Hs2 of the motor stator core is 17-17.5mm, the stator tooth width T is (5.8±0.2), and the stator core slots have two sizes of 1.9mm and 2.5mm, of which the slots with a size of 1.9mm are located on both sides of the motor q-axis direction, and the remaining slots of the stator core are 2.5mm in size. At this time, the tooth slot torque of the motor is small and the torque pulsation is low, and only the sizes of the two slots located on both sides of the q-axis are reduced, which does not affect the overall efficiency of the stator during production and offline, and ensures that the motor production efficiency is guaranteed while optimizing the NVH performance.

[0052] According to an embodiment of the present application, the permanent magnet synchronous motor includes a stator core, which is the stator core described above.

[0053] In one embodiment, the stator outer diameter Do of the permanent magnet synchronous motor is 230 mm, the stator inner diameter Di=158 mm, and the peak power is 100Kw to 1200Kw. The motor is particularly suitable for the motor reduction system of 4.5t-6t logistics vehicles.

[0054] According to an embodiment of the present application, a new energy vehicle includes the above-mentioned stator core or the above-mentioned permanent magnet synchronous motor.

[0055] It is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0056] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application. The above are only preferred implementations of the present application. 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 application, and these improvements and variations should also be regarded as the protection scope of the present application.

Claims

1. A stator core, characterized in that: The invention comprises a yoke (1) and a tooth portion (2), wherein the tooth portion (2) is located on the inner circumference of the yoke (1), tooth grooves (3) are formed between adjacent tooth portions (2), and the tooth grooves (3) are open grooves. The groove width of the tooth grooves (3) located on both sides of the q axis and adjacent to the q axis is B1, and the groove width of the other tooth grooves (3) is B0, and B1<B0.

2. The stator core according to claim 1, characterized in that: The tooth slots (3) are used to set a winding, the wire diameter of the winding is d, in units of mm, and B1≥2d.

3. The stator core according to claim 2, characterized in that: B1=2d~(2d+0.2)mm.

4. The stator core according to claim 3, characterized in that: B1 = 2.0 mm ~ 2.2 mm.

5. The stator core according to claim 1, characterized in that: B1=1.9mm, B0=2.5mm.

6. The stator core according to claim 1, characterized in that: The inner diameter of the stator core is Di, B0 / Di=0.0158, B1 / Di=0.

012.

7. The stator core according to any one of claims 1 to 6, characterized in that: The inner diameter of the stator core is Di, the outer diameter is Do, and the split ratio of the stator core is a=Di / Do=0.

687.

8. The stator core according to any one of claims 1 to 6, characterized in that: The tooth slot depth Hs2 of the stator core satisfies Hs2=17mm-17.5mm, wherein the tooth slot depth Hs2 of the stator core is the side length of the tooth slot (3) on both sides of the circumference in the cross section perpendicular to the rotor core.

9. The stator core according to any one of claims 1 to 6, characterized in that: The tooth width T of the stator core is (0.32-0.34)*Hs2, wherein Hs2 is the tooth slot depth of the stator core.

10. The stator core according to any one of claims 1 to 6, characterized in that: The circumferential width of the slot bottom of the stator core is Bs2, Bs2 = (0.4-0.42)*Hs2, where Hs2 is the tooth slot depth of the stator core.

11. A permanent magnet synchronous motor, comprising a stator core, characterized in that: The stator core is the stator core according to any one of claims 1 to 10.

12. The permanent magnet synchronous motor according to claim 11, characterized in that: The stator outer diameter Do of the permanent magnet synchronous motor is 230 mm, the stator inner diameter Di=158 mm, and the peak power is 100Kw to 1200Kw.

13. A new energy vehicle, characterized in that: The invention comprises the stator core according to any one of claims 1 to 10 or the permanent magnet synchronous motor according to claim 11 or 12.

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