CN118199303A

CN118199303A - Flat wire hairpin stator structure and motor

Info

Publication number: CN118199303A
Application number: CN202410299645.3A
Authority: CN
Inventors: 王超; 崔舜宇
Original assignee: Zhixin Technology Co Ltd
Current assignee: Zhixin Technology Co Ltd
Priority date: 2024-03-15
Filing date: 2024-03-15
Publication date: 2024-06-14

Abstract

The invention discloses a flat wire hairpin stator structure and a motor, and relates to the technical field of motor structures, comprising: the stator comprises a stator core and stator windings, wherein a plurality of stator grooves extending along the axial direction of the stator core are uniformly arranged at intervals in the circumferential direction of the inner side of the stator core; the stator winding comprises a plurality of U-shaped flat wire hairpin conductors, each flat wire hairpin conductor is inserted into two stator grooves, and the plurality of flat wire hairpin conductors are connected along the circumferential direction of the stator core to form a U-phase winding, a V-phase winding and a W-phase winding; each stator slot is internally provided with 2N layers of flat wire hairpin conductors, the flat wire hairpin conductors of the U-phase winding, the V-phase winding and the W-phase winding form two parallel branches in a short-distance single-layer connection mode, and two adjacent layers of flat wire hairpin conductors in the same stator slot are different in phase. The flat wire hairpin conductor of the embodiment of the invention is different in phase with the slot, so that the harmonic content of the motor teeth is reduced, and the NVH performance and efficiency of the motor are improved.

Description

Flat wire hairpin stator structure and motor

Technical Field

The invention relates to the technical field of motor structures, in particular to a flat wire hairpin stator structure and a motor.

Background

With the development of electric vehicle technology, the performance requirements on the vehicle motor are higher and higher, and the bottleneck of the new performance requirements of the current driving motor is difficult to break through by the round wire motor while the high slot fullness rate, the high power density and the high torque density of the motor are continuously pursued. The appearance of a flat wire hairpin (Hair-Pin) motor realizes the performance requirement which cannot be met by a round wire motor. The flat wire hairpin motor has high slot filling rate, high power density, good heat dissipation performance and NVH performance, can greatly reduce the height of the motor winding end, reduce copper consumption of windings, and further improve the efficiency of the driving motor for the vehicle.

The prior published patent CN115313701A discloses a novel 8-layer flat wire hairpin stator winding, wherein the stator winding is a 6-pole whole-distance single-layer distributed winding, and the windings are in phase with slots, so that the turn-to-turn voltage of a motor can be reduced, and the insulativity and the torque capacity of the motor are improved.

However, in the practical application process, the motor adopting the flat wire hairpin stator winding has high tooth harmonic content, poor NVH performance and low efficiency. In addition, the 1 st layer and the 8 th layer of the flat wire hairpin stator winding are connected in a same-layer crossing mode, the height of the end part is difficult to further reduce, and the structure is not compact.

Disclosure of Invention

The embodiment of the invention provides a flat wire hairpin type stator structure and a motor, which are used for solving the problems of high harmonic content of motor teeth, poor NVH performance and low efficiency caused by the fact that flat wire hairpin conductors in stator slots of the conventional flat wire hairpin type stator structure belong to the same phase in the related art.

In a first aspect, there is provided a flat wire hairpin stator structure comprising:

A stator core, wherein a plurality of stator grooves extending along the axial direction of the stator core are uniformly arranged at intervals on the inner side of the stator core;

The stator winding comprises a plurality of U-shaped flat wire hairpin conductors, each flat wire hairpin conductor is inserted into two stator grooves, and the plurality of flat wire hairpin conductors are connected along the circumferential direction of the stator core to form a U-phase winding, a V-phase winding and a W-phase winding; and

Each stator slot is internally provided with 2N layers of flat wire hairpin conductors, the flat wire hairpin conductors of the U-phase winding, the V-phase winding and the W-phase winding form two parallel branches in a short-distance single-layer connection mode, and two adjacent layers of flat wire hairpin conductors in the same stator slot are different in phase.

In some embodiments, each stator slot is provided with 1 st, 2 nd, … nd and 2N layer flat wire hairpin conductors from inside to outside, and each branch of the U-phase winding is formed by connecting 1 st, 2 nd, … th and 2N layer flat wire hairpin conductors; the wire inserting ends 1,2, … and 2N layers of the U-phase winding are formed by inserting flat wire hairpin conductors with a plurality of pitches Y1, Y2 and Y3 into the stator slots, and the welding ends of the U-phase winding are formed by straight-section twisting welding of the flat wire hairpin conductors with the pitch Y0.

In some embodiments, the rule of twisting the straight section of the flat wire hairpin conductor 21 forming the welding end of the U-phase winding is: the flat wire hairpin conductor 21 is twisted clockwise (Y0-1)/2 slots at layers 2N, … and 2 of the corresponding stator slot 11, and twisted counterclockwise (Y0-1)/2 slots at layers 2N-1, … and 1 of the corresponding stator slot 11.

In some embodiments, when N is 3 and the number of stator slots 11 is 54, pitch Y0 is 9, pitch Y1 is 10, pitch Y2 is 11, and pitch Y3 is 12.

In some embodiments, the first leg of the U-phase winding enters from the layer 6 of the 54 th slot, then enters the layer 5 and the layer 11 of the 38 th slot with a pitch y3=12, enters the layer 6 of the 19 th slot with a pitch y0=9, enters the layer 6 of the 29 th slot with a pitch y2=11, enters the layer 5 of the 48 th slot with a pitch y0=9, enters the layer 6 of the 2 nd slot with a pitch y3=12, enters the layer 5 of the 11 th slot with a pitch y0=9, enters the layer 6 of the 20 th slot with a pitch y2=11, enters the layer 5 of the 30 th slot with a pitch y0=9, enters the layer 6 of the 38 th slot with a pitch y1=10, enters the layer 5 of the 47 th slot with a pitch y2=9, enters the layer 6 of the 1 th slot with a pitch y1=10, enters the layer 5 of the layer 6 of the 18 th slot with a pitch y0=9, enters the layer 5 of the 28 th slot with a pitch y2=11, enters the layer 5 of the pitch y0=9, the layer 6 of the 36 th slot with a pitch y2=9 enters the layer 6 of the groove, the pitch y2=11 enters the layer 5 of the 3, and the wire is connected to the layer 4 th slot with a pitch 1=9, and the layer 4, and the wire is connected in the same manner as the layer 54 th slot and the layer 4, and the wire is connected to the layer 4.

In some embodiments, the second branch of the U-phase winding enters from layer 1 of slot 9 and finally exits from layer 6 of slot 9 according to the rule of the first branch.

In some embodiments, the two parallel branches of the V-phase winding and the W-phase winding have the same structural form as the two parallel branches of the U-phase winding.

In some embodiments, the U-phase winding, V-phase winding and W-phase winding are provided with a three-phase power outlet and a neutral wire at the welding end, both of which are led out by the outermost layer and the secondary outer layer of the winding.

In some embodiments, the bus bars of the three-phase power outlet and the neutral line are arranged to be curved in the circumferential direction of the stator core 1.

In a second aspect, a flat wire hairpin motor is provided that includes the flat wire hairpin stator structure described above.

The technical scheme provided by the invention has the beneficial effects that:

The embodiment of the invention provides a flat wire hairpin stator structure and a motor, which comprise a stator core and a stator winding, wherein the stator winding comprises a plurality of U-shaped flat wire hairpin conductors, the plurality of flat wire hairpin conductors are connected along the circumferential direction of a stator slot of the stator core to form a U-phase winding, a V-phase winding and a W-phase winding, the U-phase winding, the V-phase winding and the W-phase winding comprise two parallel branches and adopt a short-distance single-layer connection mode, two adjacent layers of flat wire hairpin conductors in the same stator slot are different in phase, and the flat wire hairpin conductors are different in phase in the same slot, so that the tooth harmonic content of the motor is reduced, and the NVH performance and efficiency of the motor are improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is an isometric view of a flat wire hairpin stator structure according to an embodiment of the invention;

FIG. 2 is another isometric view of a flat wire hairpin stator structure according to an embodiment of the invention;

Fig. 3 is a schematic structural diagram of a single U-shaped flat wire hairpin conductor according to an embodiment of the invention;

FIG. 4 is an enlarged partial cross-sectional view of a portion of a slot of a flat wire hairpin stator structure provided in accordance with an embodiment of the invention;

Fig. 5 is a schematic diagram illustrating a U-phase winding development of a flat wire hairpin stator structure according to an embodiment of the invention;

Fig. 6 is another schematic diagram of U-phase winding development of a flat wire hairpin stator structure according to an embodiment of the invention;

fig. 7 is a schematic structural diagram of a flat wire hairpin stator structure according to an embodiment of the invention after twisting flat wire hairpin conductors with pitches y1=10, y2=11 and y3=12;

fig. 8 is a schematic diagram of a welding structure of two flat wire hairpin conductors with a pitch y0=9 at a welding end in a flat wire hairpin stator structure according to an embodiment of the invention;

Fig. 9 is a schematic connection diagram of three-phase windings of a flat wire hairpin stator structure according to an embodiment of the invention;

In the figure:

1. A stator core; 11. a stator groove;

2. A stator winding; 21. a flat wire hairpin conductor.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

The embodiment of the invention provides a flat wire hairpin stator structure, which can solve the technical problems that flat wire hairpin conductors in stator slots of the conventional flat wire hairpin stator structure belong to the same phase, the tooth harmonic content is high, the NVH performance of a motor is poor, and the efficiency is low.

Referring to fig. 1 and 2, an embodiment of the present invention provides a flat wire hairpin stator structure including: a stator core 1 and a stator winding 2.

A plurality of stator slots 11 extending along the axial direction of the stator core 1 are uniformly arranged at intervals along the circumferential direction of the inner side of the stator core.

The stator winding 2 comprises a plurality of U-shaped flat wire hairpin conductors 21, each flat wire hairpin conductor 21 is inserted into two stator slots 11, and the plurality of flat wire hairpin conductors 21 are connected along the circumferential direction of the stator core 1 to form a U-phase winding, a V-phase winding and a W-phase winding. Fig. 3 is a schematic structural diagram of a U-shaped flat wire hairpin conductor, and a straight section of the flat wire hairpin conductor in fig. 3 is not twisted yet.

Each stator slot 11 is internally provided with 2N layers of flat wire hairpin conductors 21, the flat wire hairpin conductors 21 of the U-phase winding, the V-phase winding and the W-phase winding form two parallel branches in a short-distance single-layer connection mode, and two adjacent layers of flat wire hairpin conductors 21 in the same stator slot 11 are different in phase. Specifically, referring to fig. 4, fig. 4 is an enlarged partial sectional view of a part of the slot of the flat wire hairpin stator structure according to the embodiment of the invention, and as can be seen from fig. 4, two adjacent flat wire hairpin conductors 21 are out of phase in the same stator slot 11.

The flat wire hairpin stator structure comprises a stator core and a stator winding, wherein the stator winding comprises a plurality of U-shaped flat wire hairpin conductors, the plurality of flat wire hairpin conductors are connected along the circumferential direction of a stator slot of the stator core to form a U-phase winding, a V-phase winding and a W-phase winding, each of the U-phase winding, the V-phase winding and the W-phase winding comprises two parallel branches and adopts a short-distance single-layer connection mode, two adjacent layers of flat wire hairpin conductors in the same stator slot are out of phase, the flat wire hairpin conductors are out of phase with the slot, the harmonic content of motor teeth is reduced, and the NVH performance and efficiency of the motor are improved.

As an optional implementation manner, in an embodiment of the present invention, each stator slot 11 is provided with a1 st layer, a2 nd layer, a … nd layer, and a 2N layer of flat wire hairpin conductors 21 in sequence from inside to outside, and each branch of the U-phase winding is formed by connecting the 1 st layer, the 2 nd layer, the … th layer, and the 2N layer of flat wire hairpin conductors 21; the 1 st, 2 nd, … nd and 2N layers of the wire inserting ends of the U-phase winding are formed by inserting a plurality of flat wire hairpin conductors 21 with pitches of Y1, Y2 and Y3 into the stator slots 11, and the welding ends of the U-phase winding are formed by straight-section twisting welding of the flat wire hairpin conductors 21 with pitches of Y0. Fig. 1 is an isometric view of a wire insertion end of a flat wire hairpin stator structure, and fig. 2 is an isometric view of a welded end of a flat wire hairpin stator structure.

Further, the rule of straight-section twisting of the flat wire hairpin conductor 21 forming the welding end of the U-phase winding is: the flat wire hairpin conductor 21 is clockwise twisted (Y0-1)/2 slots at layers 2N, … and 2 corresponding to the stator slot 11, and anticlockwise twisted (Y0-1)/2 slots at layers 2N-1, … and 1 corresponding to the stator slot 11.

When N is 3 and the number of stator slots 11 is 54, the pitch Y0 is 9, the pitch Y1 is 10, the pitch Y2 is 11, and the pitch Y3 is 12.

Referring to fig. 5 and 6, taking N as 3 and the number of stator slots 11 being 54 as an example, the winding structure of the 6-layer hairpin stator structure is further described:

Referring to fig. 5, the first branch of the U-phase winding enters the layer 6 of the groove 54, then enters the layer 11 of the groove 5 at a pitch y3=12 (one flat wire hairpin conductor 21 is inserted from the wire insertion end), enters the layer 6 of the groove 19 at a pitch y0=9 (two flat wire hairpin conductors 21 are twisted at the wire insertion end), enters the layer 5 of the groove 29 at a pitch y2=11 (one flat wire hairpin conductor 21 is inserted from the wire insertion end), enters the layer 6 of the groove 37 at a pitch y0=9 (two flat wire hairpin conductors 21 are twisted at the wire insertion end), enters the layer 5 of the groove 48 at a pitch y3=12, enters the layer 6 of the groove 2 at a pitch y0=9, enters the layer 5 of the groove 11 at a pitch y2=9, enters the layer 6 of the groove 20 at a pitch y0=9, enters the layer 5 of the groove 30 at a pitch y2=9, enters the layer 38 at a pitch y2=10, enters the layer 5 at a pitch y1=10, enters the layer 6 at a pitch 1=9, enters the layer 10 at a pitch 2=9, enters the layer 6 at a pitch 2=10, enters the layer 10 at a pitch 2=10, and enters the layer 10 at a pitch 2=10 and enters the layer 6 at a pitch 2=9, the flat wire hairpin conductors 21 of the 5 th and 6 th layers enter the 4 th layer of the 54 th groove at a pitch of Y0=9, enter the 3 rd and 4 th layers of the connection, the intermediate connection mode is consistent with the 5 th and 6 th layers of the connection mode, finally enter the 2 nd layer of the 54 th groove at a pitch of Y0=9, enter the 1 nd and 2 nd layers of the connection, the intermediate connection mode is consistent with the 3 th and 4 th layers, finally, the first layer is led out from the No. 54 groove 1 layer with the pitch of Y0=9.

Referring to fig. 6, the second branch of the U-phase winding enters from layer 1 of slot 9 and finally is led out from layer 6 of slot 9 according to the rule of the first branch.

In addition, the straight-section twisting rule of the flat wire hairpin conductor 21 forming the welding end of the U-phase winding is: the flat wire hairpin conductor 21 is twisted clockwise by 4 slots at the 6 th, 4 th and 2 nd layers of the corresponding stator slot 11, and is twisted counterclockwise by 4 slots at the 5 th, … th and 1 th layers of the corresponding stator slot 11. Fig. 7 is a schematic diagram of a structure after the flat wire hairpin conductor 21 is twisted with pitches y1=10, y2=11, and y3=12. Fig. 8 is a schematic diagram of a structure in which two flat wire hairpin conductors 21 are twisted at a welding end at a pitch y0=9.

According to the flat wire hairpin stator structure provided by the embodiment of the invention, the welding ends of the flat wire hairpin stator structure are not provided with bridge wires, so that the number of special-shaped wires is reduced, the layout of winding end parts is simplified, the feasibility of a mass production manufacturing process of windings is improved, and the wire insertion is facilitated. The flat wire hairpin conductor has less linear dies, can reduce die opening cost, has the same twisting distance of the welding end, can greatly simplify the production process and improves the production efficiency. In addition, according to the flat wire hairpin stator structure provided by the embodiment of the invention, through pole replacement of the inner layer and the outer layer, the same-layer straddling, back-twisting and the like are avoided, the height of the end part can be further reduced, and the production cost and the wire plugging difficulty of the hairpin wire are reduced.

As an alternative implementation manner, in an embodiment of the present invention, the structural form of the two parallel branches of the V-phase winding and the W-phase winding is the same as the structural form of the two parallel branches of the U-phase winding. The rule of the V-phase winding or the W-phase winding is the same, so that the volume production efficiency of the winding is improved. Fig. 9 is a schematic diagram of the connection of three-phase windings.

In an embodiment of the present invention, the U-phase winding, the V-phase winding, and the W-phase winding are provided with a three-phase power outlet and a neutral wire at the welding end, and the three-phase power outlet and the neutral wire are led out from the outermost layer and the secondary outer layer of the winding. Referring to fig. 1 and 2, the U-phase winding lead-out terminals u1_in (u1_out) and u2_in (u2_out), and similarly, the V-phase winding and W-phase winding lead-out terminals v1_in (v1_out) and v2_in (v2_out), wherein subscripts 1 and 2 respectively correspond to a first branch and a second branch of each phase winding. The u1_out, u2_out, v1_out, v2_out, w1_out, w2_out are connected to a neutral point. Three-phase power lead-out wire U phase: u1_in, u2_in; v phase: v1_in, v2_in; w phase: w1_in, w2_in. The welding end is only provided with a three-phase power lead-out wire and a neutral wire, so that the structural layout of the end special-shaped wire is greatly simplified, and the space size of the end part of the motor winding is reduced.

As an alternative implementation manner, in an embodiment of the invention, the bus bars of the three-phase power lead-out wire and the neutral wire are arranged in a bending manner along the circumferential direction of the stator core (1), so that the automatic production is facilitated.

The embodiment of the invention provides a flat wire hairpin motor, which comprises the flat wire hairpin stator structure. The flat wire hairpin stator structure includes: a stator core 1 and a stator winding 2.

In the description of the present invention, it should be noted that the azimuth or positional relationship indicated by the terms "upper", "lower", etc. are based on the azimuth or positional relationship shown in the drawings, and are merely for convenience of describing the present invention and simplifying the description, and are not indicative or implying that the apparatus or element in question must have a specific azimuth, be constructed and operated in a specific azimuth, and thus should not be construed as limiting the present invention. Unless specifically stated or limited otherwise, the terms "mounted," "connected," and "coupled" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

It should be noted that in the present invention, relational terms such as "first" and "second" and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

The foregoing is only a specific embodiment of the invention to enable those skilled in the art to understand or practice the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features of the invention herein.

Claims

1. A flat wire hairpin stator structure comprising:

a stator core (1) having a plurality of stator slots (11) extending in the axial direction of the stator core at regular intervals in the circumferential direction;

The stator winding (2) comprises a plurality of U-shaped flat wire hairpin conductors (21), each flat wire hairpin conductor (21) is inserted into two stator slots (11), and the plurality of flat wire hairpin conductors (21) are connected along the circumferential direction of the stator core (1) to form a U-phase winding, a V-phase winding and a W-phase winding; and

Each stator slot (11) is internally provided with 2N layers of flat wire hairpin conductors (21), the flat wire hairpin conductors (21) of the U-phase winding, the V-phase winding and the W-phase winding form two parallel branches in a short-distance single-layer connection mode, and two adjacent layers of flat wire hairpin conductors (21) in the same stator slot (11) are different in phase.

2. The flat wire hairpin stator structure of claim 1 wherein:

Each stator slot (11) is provided with a 1 st layer, a2 nd layer, a … nd layer and a 2N layer of flat wire hairpin conductors (21) from inside to outside, and each branch of the U-phase winding is formed by connecting the 1 st layer, the 2 nd layer, the … th layer and the 2N layer of flat wire hairpin conductors (21); the wire inserting ends 1, 2, … and 2N layers of the U-phase winding are formed by inserting flat wire hairpin conductors (21) with a plurality of pitches Y1, Y2 and Y3 into the stator slots (11), and the welding ends of the U-phase winding are formed by straight-section torsion welding of the flat wire hairpin conductors (21) with the pitches Y0.

3. The flat wire hairpin stator structure of claim 2 wherein:

the rule of twisting the straight section of the flat wire hairpin conductor (21) forming the welding end of the U-phase winding is as follows: the flat wire hairpin conductor (21) is clockwise twisted (Y0-1)/2 grooves at the 2N, … and 2 layers of the corresponding stator groove (11), and anticlockwise twisted (Y0-1)/2 grooves at the 2N-1, … and 1 layer of the corresponding stator groove (11).

4. The flat wire hairpin stator structure of claim 3 wherein:

When N is 3 and the number of the stator slots (11) is 54, the pitch Y0 is 9, the pitch Y1 is 10, the pitch Y2 is 11 and the pitch Y3 is 12.

5. The flat wire hairpin stator structure of claim 4 wherein:

The first branch of the U-phase winding enters from the 54 th slot 6 th layer, then enters the 5 th slot 11 th layer with a pitch y3=12, enters the 19 th slot 6 th layer with a pitch y0=9, enters the 29 th slot 5 th layer with a pitch y2=11, enters the 37 th slot 6 th layer with a pitch y0=9, enters the 48 th slot 5 th layer with a pitch y3=12, enters the 2 nd slot 6 th layer with a pitch y2=11, enters the 11 th slot 5 th layer with a pitch y0=9, enters the 20 th slot 6 th layer with a pitch y2=11, enters the 30 th slot 5 th layer with a pitch y0=9, enters the 38 th slot 6 th layer with a pitch y1=10, enters the 47 th slot 5 th layer with a pitch y0=9, enters the 1 th slot 6 th layer with a pitch y1=10, enters the 18 th slot 5 th layer with a pitch y0=9, enters the 28 th slot 5 th layer with a pitch y2=9, enters the 36 th slot 6 th layer with a pitch y2=9, enters the 46 th slot 5 th layer with a pitch y2=9, the flat wire hairpin conductors 21 of the 5 th layer and the 6 th layer enter the 4 th layer of the 54 th groove at a pitch of Y0=9, enter the 3 rd layer and the 4 th layer of the 54 th groove to be connected, the intermediate connection mode is consistent with the 5 th layer and the 6 th layer of the 54 th groove, finally enter the 2 nd layer of the 54 th groove at a pitch of Y0=9 to enter the 1 st layer and the 2 nd layer of the 54 th groove to be connected, the intermediate connection mode is consistent with the 3 th layer and the 4 th layer, and finally be led out from the 1 st layer of the 54 th groove at a pitch of Y0=9.

6. The flat wire hairpin stator structure of claim 5 wherein:

And a second branch of the U-phase winding enters from the layer 1 of the No. 9 slot and finally is led out from the layer 6 of the No. 9 slot according to the rule of the first branch.

7. The flat wire hairpin stator structure of claim 6 wherein:

The structural form of the two parallel branches of the V-phase winding and the W-phase winding is the same as that of the two parallel branches of the U-phase winding.

8. The flat wire hairpin stator structure of claim 6 wherein:

and the U-phase winding, the V-phase winding and the W-phase winding are provided with three-phase power outgoing lines and neutral wires at welding ends, and the three-phase power outgoing lines and the neutral wires are led out from the outermost layer and the secondary outer layer of the winding.

9. The flat wire hairpin stator structure of claim 8 wherein:

the bus bars of the three-phase power outgoing lines and the neutral lines are arranged in a bending mode along the circumferential direction of the stator core (1).

10. A flat wire hairpin motor comprising a flat wire hairpin stator structure of any one of claims 1-9.