Concentric unequal-turn full-slot low-harmonic winding stator

Abstract

The invention discloses a concentric unequal-turn full-slot low-harmonic winding stator, which comprises a stator core and a winding, and is characterized in that the stator core comprises a plurality of phase belts, and each phase belt comprises three stator slots; the windings wound in the three stator slots in one phase belt are wound in a single-double-layer unequal-turn manner, and are periodically distributed on the whole stator core in a surrounding manner by taking one phase belt as a period; the three stator slots in one phase belt comprise two first slot bodies and a second slot body, the second slot body is located between the two first slot bodies, and the slot sizes of the first slot bodies and the second slot body are matched with the single-layer and double-layer unequal-turn winding windings to form a matching structure with high full slot rate. The concentric single-layer and double-layer unequal-turn windings and the stator slots matched with the windings are adopted, so that the magnetic circuit distribution is more uniform while the harmonic amplitude is reduced, the static flux density distribution of the stator is greatly improved, and the motor performance is further improved.

Description

Technical Field

[0001] The invention belongs to the technical field of motors, and in particular relates to a concentric unequal turn-full slot low harmonic winding stator. Background Art

[0002] With the continuous development of the motor industry, the requirements for motor energy efficiency and performance are also gradually increasing. From IE2 motors to the current IE5 motors, under the condition of the same material usage, traditional design ideas have been difficult to meet the existing performance requirements. Through electromagnetic software analysis and optimization of traditional design methods, finding a design solution to reduce motor losses and improve performance is what is needed now.

[0003] Among them, for three-phase asynchronous motors, although the existing three-phase asynchronous motors have the advantages of simple structure, reliable operation, low cost, etc., they mostly adopt relatively simple double-layer concentric winding and unified stator slot design ideas, and there is still corresponding optimization space in the stator winding and stator slot. For this reason, the present invention proposes a concentric unequal turn full slot low harmonic winding stator. Summary of the invention

[0004] The present invention aims at solving the problems in the prior art and proposes the following technical solutions:

[0005] A concentric unequal-turn-full-slot low-harmonic winding stator comprises a stator core and a winding, wherein the stator core comprises a plurality of phase belts, and each phase belt comprises three stator slots;

[0006] The windings wound in the three stator slots in one phase band are wound in a single-layer or double-layer unequal-turn manner, and are periodically wrapped around the entire stator core with one phase band as a period;

[0007] The three stator slots in a phase band include two first slot bodies and one second slot body, and the second slot body is located between the two first slot bodies. The slot sizes of the first slot body and the second slot body are adapted to the single- and double-layer unequal-turn windings to form a matching structure with a high full slot rate.

[0008] As a preferred embodiment of the above technical solution, the number of turns of the windings wound in the three stator slots in one phase band is arranged in a more-less-more manner.

[0009] As a preferred embodiment of the above technical solution, the oblique shoulders of the first trough body and the second trough body both adopt an arc-shaped structure.

[0010] As a preferred embodiment of the above technical solution, the winding adopts a single-layer and double-layer turn form, an insulating partition is provided in the stator slot, and the insulating partition is used to divide the single-layer and double-layer turns of the winding.

[0011] As a preferred embodiment of the above technical solution, the uniformity ratio of the stator tooth magnetic density and the yoke magnetic density is equal, that is, the ratio of the stator tooth area to the yoke area is 1:1.

[0012] A rotor is adapted to the above-mentioned concentric unequal-turn slot-full low-harmonic winding stator. The rotor comprises a rotor body, on which knife-shaped rotor slots are arranged. The knife-shaped rotor slots are overall elongated knife-shaped slots.

[0013] The beneficial effects of the present invention are:

[0014] 1. Compared with the traditional concentric double-layer equal-turn winding, the concentric single-layer and double-layer unequal-turn winding in the present invention can effectively reduce the amplitude and comprehensive strength of each harmonic, and achieve the purpose of optimizing the motor performance by reasonably adjusting the distribution of turns and span. The single-layer and double-layer unequal-turn winding has a significant effect on reducing stray losses, reducing harmonic content, improving starting performance, reducing motor temperature rise, and improving efficiency;

[0015] 2. The present invention further improves the stator slots, dividing them into a first slot body and a second slot body, which is more suitable for single-layer and double-layer unequal-turn concentric windings, so that they have a higher slot fill rate and improve the slot utilization rate; while applying the advantages of single-layer and double-layer unequal-turn concentric windings, it also makes the magnetic circuit distribution more uniform, greatly improves the static magnetic flux distribution of the stator, and further improves the motor performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 What is shown is a slicing diagram of the stator and rotor matching of the concentric unequal turns full slot low harmonic winding of the present invention;

[0017] Figure 2 What is shown is a schematic diagram of the three-dimensional structure of the concentric unequal turn-filled slot low harmonic winding stator of the present invention;

[0018] Figure 3 Shown is a comparison diagram of rotor slots in the rotor of the present invention;

[0019] Figure 4 Shown is a partial view of a stator with concentric equal turns and equal slots windings in Comparative Example 1;

[0020] Figure 5 The figure shows the amplitude and comprehensive strength of each harmonic of the stator with concentric equal turns and equal slot windings in comparative example 1;

[0021] Figure 6 Shown is a partial view of the stator of the concentric unequal turns and equal slots low harmonic winding in Comparative Example 2;

[0022] Figure 7 The figure shows the harmonic amplitude and comprehensive strength of the stator of the concentric unequal turns and equal slots low harmonic winding in comparative example 2;

[0023] Figure 8 The figure shows a partial view of the stator of the concentric unequal turns and full slots low harmonic winding in Example 1;

[0024] Fig. 9 , Fig.10 What is shown is the static magnetic flux distribution diagram of the stator of the concentric unequal turns and full slots low harmonic winding in Example 1.

[0025] In the figure: 10, stator core; 11, stator slot; 111, first slot body; 112, second slot body; 20, winding; 30, rotor body; 31, knife-shaped rotor slot; 32, convex rotor slot. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments.

[0027] like Figure 1 , Figure 2 As shown, a concentric unequal-turn-full-slot low-harmonic winding stator comprises a stator core 10 and a winding 20, wherein the stator core 10 comprises a plurality of phase belts, and each phase belt comprises three stator slots 11;

[0028] The winding 20 wound in three stator slots 11 in one phase band is wound in a single-layer or double-layer unequal-turn manner, and is periodically wrapped around the entire stator core 10 with one phase band as a period;

[0029] The three stator slots 11 in a phase band include two first slot bodies 111 and one second slot body 112, and the second slot body 112 is located between the two first slot bodies 111. The slot sizes of the first slot body 111 and the second slot body 112 are adapted to the single- and double-layer unequal-turn winding 20 to form a matching structure with a high full slot rate.

[0030] The number of turns of the winding 20 wound in the three stator slots 11 in a phase band is arranged in a more-less-more manner. The winding 20 in a phase band of the present invention is arranged in a more-less-more manner to optimize the motor performance, effectively reduce harmonics, and has a significant effect on reducing stray losses, improving starting performance, reducing motor temperature rise, and improving efficiency.

[0031] The oblique shoulders of the first slot body 111 and the second slot body 112 are both arc-shaped structures. The arc-shaped structure not only fits better with the circumferential surface of a single turn of the winding 20, further optimizing the full slot rate of the stator slot 11, but also effectively reduces the wear of the turns during the winding process.

[0032] The winding 20 is in the form of single-layer and double-layer turns. An insulating partition is provided in the stator slot 11 , and the insulating partition is used to separate the single-layer and double-layer turns of the winding 20 .

[0033] The uniformity ratio of the stator tooth magnetic flux density and the yoke magnetic flux density is equal, that is, the ratio of the stator tooth area to the yoke area is 1:1. Experimental verification shows that this ratio is more conducive to the distribution of the stator magnetic circuit.

[0034] like Figure 1 , Figure 3 As shown, a rotor is adapted to the above-mentioned concentric unequal turn slot low harmonic winding stator, and the rotor includes a rotor body 30, and a knife-shaped rotor slot 31 is provided on the rotor body 30. The knife-shaped rotor slot 31 adopts an overall slender knife-shaped slot. Compared with the traditional convex rotor slot 32, the slender knife-shaped rotor slot 31 is more compatible with the stator in the present invention, and the rotor loss can be further reduced, thereby improving the motor efficiency.

[0035] Comparative Example 1

[0036] like Figure 3 As shown, a H160-4-pole motor is used, the number of stator slots is 36, and a concentric equal-turn and equal-slot winding stator is adopted, including a stator core 10 and a winding 20, the stator core 10 includes a plurality of phase belts, and each phase belt includes three stator slots 11;

[0037] The windings 20 wound in three stator slots 11 in one phase band are wound in a double-layer equal-turn manner, and are periodically wrapped around the entire stator core 10 with one phase band as a period;

[0038] The three stator slots 11 in one phase band have the same size and structure and are evenly distributed, and the stator slots 11 and the number of winding turns of the winding 20 match each other.

[0039] like Figure 5 As shown, the amplitudes and comprehensive intensities of the harmonics of the stator of comparative example 1 are obtained by the harmonic calculation software.

[0040] It should be added that: A brief description of the 5th, 7th and 11th harmonic intensity of the comprehensive reaction is:

[0041] Fundamental harmonics usually refer to low-order harmonics. The industry standard uses 5th, 7th, and 11th order data statistics to influence the motor in the following aspects:

[0042] Additional losses and reduced efficiency: Harmonic currents will generate additional losses in the motor stator winding, rotor circuit and core, resulting in a reduction in the overall energy conversion efficiency of the motor. These additional losses include increased copper loss, which will cause local overheating of the motor under severe harmonic loads.

[0043] Increased temperature rise and insulation aging: The additional heat caused by harmonic current will cause the motor temperature to increase. Under long-term operation, it will accelerate the aging process of the motor insulation layer, reduce the insulation strength, and may even break through the insulation layer, causing failures.

[0044] Vibration and noise: Harmonic currents can also cause torque pulsation in the motor, resulting in increased vibration and noise when the motor is running, affecting the smooth operation and working environment of the motor.

[0045] Bearing damage: Harmonic currents have an adverse effect on motor bearings, which may cause pitting, dents, and cracks in the bearings, shortening the service life of the bearings.

[0046] Overall performance degradation: The combined impact of harmonics on the motor will cause the overall performance of the motor to degrade, including unstable output power, reduced operating efficiency, etc. In severe cases, it may affect the normal use of the motor.

[0047] In summary, fundamental harmonics have many effects on motors, mainly concentrated in additional losses, increased temperature rise, insulation aging, vibration noise, and bearing damage. These effects will reduce the operating efficiency and reliability of the motor and shorten the service life of the motor. Therefore, in the design and use of motors, it is necessary to fully consider the impact of harmonics and take corresponding measures to suppress and eliminate harmonics.

[0048] Comparative Example 2

[0049] like Figure 6 As shown, a H160-4-pole motor is used, the number of stator slots is 36, and a concentric unequal turns and equal slots low harmonic winding stator is adopted, including a stator core 10 and a winding 20, the stator core 10 includes a plurality of phase belts, and each phase belt includes three stator slots 11;

[0050] The winding 20 wound in three stator slots 11 in one phase band is wound in a single-layer or double-layer unequal-turn manner, and is periodically wrapped around the entire stator core 10 with one phase band as a period;

[0051] The three stator slots 11 in one phase band have the same size and structure and are evenly distributed.

[0052] like Figure 7 As shown, the amplitudes and comprehensive intensities of the harmonics of the stator of comparative example 2 are obtained by the harmonic calculation software.

[0053] Depend on Figure 5 , Figure 7 From the data comparison, it can be seen that compared with the concentric double-layer equal-turn winding 20, the concentric single-layer and double-layer unequal-turn winding 20 can effectively reduce the amplitude and comprehensive intensity of each harmonic, and achieve the purpose of optimizing the motor performance by reasonably adjusting the distribution of turns and span distribution. The single-layer and double-layer unequal-turn winding has a significant effect on reducing stray losses, reducing harmonic content, improving starting performance, reducing motor temperature rise, and improving efficiency.

[0054] Although the single-layer and double-layer unequal-turn concentric winding 20 has the above advantages, due to the unequal distribution of the number of turns, it still has disadvantages when used in the traditional stator slot structure, such as low slot utilization and poor stator magnetic flux uniformity. In order to solve the above problems from a technical principle, the present invention further improves the stator slot 11.

[0055] Example 1

[0056] like Figure 8 As shown, a H160-4-pole motor is used, the number of stator slots is 36, and a concentric unequal turn full slot low harmonic winding stator is adopted, including a stator core 10 and a winding 20, the stator core 10 includes a plurality of phase belts, and each phase belt includes three stator slots 11;

[0057] The winding 20 wound in three stator slots 11 in one phase band is wound in a single-layer or double-layer unequal-turn manner, and is periodically wrapped around the entire stator core 10 with one phase band as a period;

[0058] The three stator slots 11 in a phase band include two first slot bodies 111 and one second slot body 112, and the second slot body 112 is located between the two first slot bodies 111. The slot sizes of the first slot body 111 and the second slot body 112 are adapted to the single- and double-layer unequal-turn winding 20 to form a matching structure with a high full slot rate.

[0059] Depend on Figure 6 , Figure 8 By comparison, it can be seen that the present invention further improves the stator slot 11 to be more suitable for the single-layer and double-layer unequal-turn concentric winding 20, so that it has a higher slot fill rate and improves the slot utilization rate.

[0060] Depend on Fig. 9 , Fig.10 It can be seen that the further improved stator slot 11 of the present invention, while applying the advantages of the single-layer and double-layer unequal-turn concentric winding 20, also makes the magnetic circuit distribution more uniform, greatly improves the static magnetic flux distribution of the stator, and further improves the motor performance.

[0061] The above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them.

Claims

1. A concentric unequal-turn-full-slot low-harmonic winding stator, comprising a stator core (10) and a winding (20), characterized in that: The stator core (10) comprises a plurality of phase belts, each of the phase belts comprises three stator slots (11); The windings (20) wound in the three stator slots (11) in one phase band are wound in a single-layer or double-layer unequal-turn manner, and are periodically wrapped around the entire stator core (10) with one phase band as a period; The three stator slots (11) in a phase band include two first slot bodies (111) and one second slot body (112), and the second slot body (112) is located between the two first slot bodies (111), and the slot sizes of the first slot body (111) and the second slot body (112) are matched with the single- and double-layer unequal-turn winding winding (20) to form a matching structure with a high slot full rate.

2. The concentric unequal-turn-full-slot low-harmonic winding stator according to claim 1, characterized in that: The number of turns of the winding (20) wound in the three stator slots (11) in one phase band is arranged in a more-less-more manner.

3. The concentric unequal-turn-full-slot low-harmonic winding stator according to claim 1, characterized in that: The oblique shoulders of the first trough body (111) and the second trough body (112) both have an arc-shaped structure.

4. The concentric unequal-turn-full-slot low-harmonic winding stator according to claim 1, characterized in that: The winding (20) is in the form of a single-layer and double-layer winding, and an insulating partition is provided in the stator slot (11), and the insulating partition is used to separate the single-layer and double-layer windings of the winding (20).

5. The concentric unequal-turn-full-slot low-harmonic winding stator according to claim 1, characterized in that: The uniformity ratio of the stator tooth magnetic flux density and the yoke magnetic flux density is equal, that is, the ratio of the stator tooth area to the yoke area is 1:

1.

6. A rotor, characterized in that: The rotor is compatible with the concentric unequal-turn slot-full low-harmonic winding stator described in any one of claims 1 to 5, and the rotor comprises a rotor body (30) on which knife-shaped rotor slots (31) are arranged, and the knife-shaped rotor slots (31) are overall elongated knife-shaped slots.

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