CN221842388U - Vehicle, powertrain, flat wire motor and stator thereof - Google Patents

Abstract

The present application discloses a vehicle, a powertrain, a flat wire motor and its stator. The stator includes: a stator core, the inner wall of the stator core is evenly distributed with s stator slots along its circumference, and the stator slots are divided into n slot layers along the radial direction of the stator core; a stator winding, including three-phase windings arranged in a periodic manner in sequence along the circumference of the stator core, each phase winding includes q parallel branches, the q parallel branches are rotationally symmetrical in the circumferential direction, each of the parallel branches includes a plurality of hairpin coils with different pitches, and each of the stator slots is provided with n layers of flat wire conductors of the hairpin coils; wherein s, n, and q are all positive integers. Through the above method, the present application can make the magnetic field distribution of each winding on the stator of the flat wire motor the same, maintain the potential balance, and avoid the generation of branch circulation, which is conducive to improving the operating efficiency of the flat wire motor and avoiding local overheating of the winding.

Description

Vehicle, powertrain, flat wire motor and stator thereof

This application claims priority to a prior patent application with application number 202210873537.3 filed on July 22, 2022 and invention name “A stator assembly, a motor having the same, and an electric vehicle”, which is incorporated herein by reference in its entirety.

Technical Field

The present application relates to the technical field of flat wire motors, and in particular to a vehicle, a power assembly, a flat wire motor and a stator thereof.

Background Art

With the vigorous promotion of new energy vehicles, new energy electric vehicles are becoming more and more popular, and the market demand for the performance of electric vehicle power systems is constantly increasing. The main drive motor is the power output component of the power system and one of the most core components of electric vehicles. The performance index requirements of the main drive motor are also getting higher and higher, such as high power density and torque density, small size and light weight. With the development of flat wire technology, electric vehicle motors are gradually using flat wire windings, which can improve the stator slot full rate and further improve the motor power density, efficiency and thermal conductivity.

Existing flat wire motors mainly use a winding structure of wave winding or stacked winding. By designing the flat wire conductor in the winding structure into multiple layers, the AC resistance of the motor can be effectively reduced. However, as the number of layers of flat wire conductors increases, the wiring method of the winding structure is also different. In the prior art, when the branches of each phase of the stator winding are connected, the twisting direction of the outer end of the coil slot or the twisting slot spacing will be inconsistent, and there are many types of hairpin coils used, resulting in complex manufacturing processes, difficult forming, high production costs, and low processing efficiency. In addition, for the complex structure of the motor winding, potential imbalance is likely to occur between the branches of the same phase, resulting in the formation of circulating currents between the branches, affecting the efficiency and temperature rise of the motor.

Utility Model Content

The present application mainly provides a vehicle, a power assembly, a flat wire motor and a stator thereof, so as to solve the problem that potential imbalance is easy to occur in the flat wire motor, resulting in the formation of circulating current between branches.

In order to solve the above technical problems, a technical solution adopted in the present application is: to provide a stator of a flat wire motor. The stator comprises: a stator core, the inner wall of the stator core is uniformly distributed with s stator slots along its circumference, and the stator slots are divided into n slot layers along the radial direction of the stator core; a stator winding, comprising three-phase windings arranged in a periodic manner in sequence along the circumference of the stator core, each phase winding comprises q parallel branches, the q parallel branches are rotationally symmetrical in the circumferential direction, each of the parallel branches comprises a plurality of hairpin coils with different pitches, and each of the stator slots is provided with n layers of flat wire conductors of the hairpin coils; wherein s, n, and q are all positive integers.

In some embodiments, the number q of parallel branches included in each phase winding is 1 or 2, the number s of the stator slots is 54 or 72, and the number n of slot layers of the stator slots is 4, 6, 8 or 10.

In some embodiments, q is 1, n is 4 or 8, and the hairpin coil pitch combination of any of the parallel branches in the first slot layer or the nth slot layer is 7, 8, 10, 8, 9, 10, or 8, 10, 11.

In some embodiments, q is 1, n is 6 or 10, and the hairpin coil pitch combination of any of the parallel branches in the first slot layer or the nth slot layer is 8, 9, 10, 7, 8, 8, 10, 11, or 7, 8, 10.

In some embodiments, q is 2, and the pitch of the hairpin coils of any of the parallel branches in the first slot layer or the nth slot layer is 8 or 10.

In some embodiments, the hairpin coil pitch of any of the parallel branches from the 2nd layer to the n-1th layer is 9, and the welding pitch of any of the parallel branches from the 2nd slot layer to the n-1th slot layer is 9.

In some embodiments, the number q of parallel branches included in each phase winding is 2 or 4, the number s of the stator slots is 72, and the number n of slot layers of the stator slots is 5 or 7.

In some embodiments, the hairpin coil pitch of the parallel branch in the 1st slot layer is 7 and/or 13, the hairpin coil pitch of the parallel branch in the nth slot layer is 7 and/or 13, the welding pitch of the parallel branch in the first slot layer or the nth slot layer is 13, and the winding method of the winding is wave winding.

In some embodiments, the hairpin coil pitch of the parallel branch in the first slot layer is 13 and/or 15, the hairpin coil pitch of the parallel branch in the nth slot layer is 13 and/or 15, the welding pitch of the parallel branch in the first slot layer or the nth slot layer is 11 and/or 13, and the winding method of the winding is stacked winding.

In some embodiments, the pitch of the hairpin coil between the 2nd slot layer and the n-1th slot layer in any of the parallel branches is 12.

In some embodiments, the hairpin coil of each of the parallel branches traverses n slot layers in different stator slots.

In some embodiments, the voltage lead wire of any of the parallel branches is located at the 1st slot layer or the nth slot layer, and the neutral point lead wire of any of the parallel branches is located at the 1st slot layer or the nth slot layer.

To solve the above technical problem, another technical solution adopted by the present application is to provide a flat wire motor. The flat wire motor comprises a rotor and the above stator, wherein the rotor is arranged in a space surrounded by the inner wall of the stator core.

In order to solve the above technical problem, another technical solution adopted by the present application is to provide a power assembly, which includes a reducer and the flat wire motor as described above, wherein the flat wire motor is drivingly connected to the reducer.

In order to solve the above technical problem, another technical solution adopted by the present application is: to provide a vehicle. The vehicle includes the powertrain as described above.

The beneficial effects of the present application are as follows: Different from the prior art, the present application discloses a vehicle, a powertrain, a flat wire motor and a stator thereof. By making the multiple parallel branches of each phase winding rotationally symmetrical in the circumferential direction, the magnetic field distribution of the multiple parallel branches in each phase winding is the same, and the potential is balanced, thereby avoiding the circulating current generated between the parallel branches, thereby greatly reducing the additional AC copper loss at high frequency, improving the efficiency of the flat wire motor at high speed, avoiding local overheating of the winding, and extending the life of the flat wire motor; and the hairpin coil of each parallel branch traverses N slot layers in different stator slots, thereby eliminating the potential phase difference caused by the position of the multiple parallel branches in each phase winding in the stator slot.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work, among which:

FIG1 is a schematic structural diagram of a stator of a flat wire motor according to an embodiment of the present application;

FIG. 2 is a schematic diagram of the structure of the stator core in the stator shown in FIG. 1

FIG3 is a schematic diagram of the structure of a hairpin coil in the stator as shown in FIG1 ;

FIG4 is another schematic diagram of the structure of the hairpin coil in the stator shown in FIG1 ;

5 is a first winding schematic diagram of the first parallel branch of the U-phase winding when the flat wire motor provided by the present application has 6 poles and 54 slots, q is 2, and n is 4;

6 is a second winding schematic diagram of the first parallel branch of the U-phase winding when the flat wire motor provided by the present application has 6 poles and 54 slots, q is 2, and n is 4;

7 is a third winding schematic diagram of the first parallel branch of the U-phase winding when the flat wire motor provided by the present application has 6 poles and 54 slots, q is 2, and n is 4;

8 is a first winding schematic diagram of the second parallel branch of the U-phase winding when the flat wire motor provided by the present application has 6 poles and 54 slots, q is 2, and n is 4;

9 is a second winding schematic diagram of the second parallel branch of the U-phase winding when the flat wire motor provided by the present application has 6 poles and 54 slots, q is 2, and n is 4;

10 is a third winding schematic diagram of the second parallel branch of the U-phase winding when the flat wire motor provided by the present application has 6 poles and 54 slots, q is 2, and n is 4;

11 is a first winding schematic diagram of the first parallel branch of the U-phase winding when the flat wire motor provided by the present application has 6 poles and 54 slots, q is 2, and n is 6;

12 is a second winding schematic diagram of the first parallel branch of the U-phase winding when the flat wire motor provided by the present application has 6 poles and 54 slots, q is 2, and n is 6;

13 is a third winding schematic diagram of the first parallel branch of the U-phase winding when the flat wire motor provided by the present application has 6 poles and 54 slots, q is 2, and n is 6;

14 is a first winding schematic diagram of the second parallel branch of the U-phase winding when the flat wire motor provided by the present application has 6 poles and 54 slots, q is 2, and n is 6;

15 is a second winding schematic diagram of the second parallel branch of the U-phase winding when the flat wire motor provided by the present application has 6 poles and 54 slots, q is 2, and n is 6;

16 is a third winding schematic diagram of the second parallel branch of the U-phase winding when the flat wire motor provided by the present application has 6 poles and 54 slots, q is 2, and n is 6;

FIG17 is a first winding schematic diagram of a U-phase winding when the flat wire motor provided by the present application has 6 poles and 54 slots, q is 1, and n is 4;

FIG18 is a second winding schematic diagram of the U-phase winding when the flat wire motor provided by the present application has 6 poles and 54 slots, q is 1, and n is 4;

19 is a third winding schematic diagram of the U-phase winding when the flat wire motor provided by the present application has 6 poles and 54 slots, q is 1, and n is 4;

FIG20 is a first winding schematic diagram of a U-phase winding when the flat wire motor provided by the present application has 6 poles and 54 slots, q is 1, and n is 6;

21 is a second winding schematic diagram of the U-phase winding when the flat wire motor provided by the present application has 6 poles and 54 slots, q is 1, and n is 6;

FIG22 is a third winding schematic diagram of the U-phase winding when the flat wire motor provided by the present application has 6 poles and 54 slots, q is 1, and n is 6;

23 is a first winding schematic diagram of the first parallel branch of the U-phase winding when the flat wire motor provided by the present application has 6 poles and 72 slots, q is 2, and n is 5;

24 is a first winding schematic diagram of the second parallel branch of the U-phase winding when the flat wire motor provided by the present application has 6 poles and 54 slots, q is 2, and n is 5;

25 is a second winding schematic diagram of the first parallel branch of the U-phase winding when the flat wire motor provided by the present application has 6 poles and 72 slots, q is 2, and n is 5;

26 is a second winding schematic diagram of the second parallel branch of the U-phase winding when the flat wire motor provided by the present application has 6 poles and 54 slots, q is 2, and n is 5.

DETAILED DESCRIPTION

The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

The terms "first", "second" and "third" in the embodiments of the present application are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first", "second" and "third" may explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units that are not listed, or optionally also includes other steps or units inherent to these processes, methods, products or devices.

Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

For ease of understanding, the professional terms appearing in this application are explained below.

Stator: refers to the stationary part of the motor, whose function is to generate a rotating magnetic field.

Rotor: refers to the rotating part in the motor, which is used to realize the conversion of electrical energy into mechanical energy.

Span: refers to the distance between the two sides of the same element in the motor winding on the armature surface, usually expressed by the number of stator slots opened on the stator core.

Referring to FIG. 1 and FIG. 2 , FIG. 1 is a schematic structural diagram of a stator of a flat wire motor according to an embodiment of the present application, and FIG. 2 is a schematic structural diagram of a stator core in the stator shown in FIG. 1 .

An embodiment of the present application provides a flat wire motor, which includes a rotor and a stator. The rotor is arranged in a space formed by the inner wall of the stator core of the stator. The number of poles of the rotor is p, the number of poles of the rotor is 2p, and the stator includes an m-phase winding. The number of slots per pole and per phase of the flat wire motor is q=s/(2pm), s is the number of stator slots, q can be 2 or 3, etc. The slot-pole combination of the flat wire motor can be 6 poles and 54 slots, 8 poles and 72 slots, 10 poles and 90 slots or 12 poles and 108 slots, etc., and the present application does not make any specific restrictions on this.

As shown in FIG. 1 , the stator of the flat wire motor includes a stator core 10 and a stator winding 20 .

As shown in FIG2 , the inner wall of the stator core 10 is provided with s evenly distributed stator slots 11 along its circumference, where s is a positive integer and the number of the stator slots 11 is a multiple of 3. For example, the number of the stator slots 11 may be 48, 54 or 72, and any stator slot 11 extends in the axial direction of the stator core 10 and penetrates the inner wall of the stator core 10 along the axial direction of the stator core 10. The stator slot 11 is also divided into n slot layers along the radial direction of the stator core 10, and each slot layer of the stator slot 11 is provided with a flat wire conductor.

The stator winding 20 includes three-phase windings arranged in a periodic manner in sequence along the circumference of the stator core 10, and the three-phase windings are respectively a U-phase winding, a V-phase winding, and a W-phase winding. Each phase winding includes p parallel branches, q is a positive integer, and the p parallel branches are rotationally symmetrical in the circumferential direction; for example, each phase winding includes two parallel branches, and the two parallel branches are rotationally symmetrical in the circumferential direction of the stator core 10.

By limiting the rotational symmetry of multiple parallel branches in each winding in the circumferential direction, the magnetic field distribution of multiple parallel branches in each phase winding is made the same and the potential is balanced, thereby avoiding the circulating current generated between the parallel branches, thereby greatly reducing the additional AC copper loss at high frequency, improving the efficiency of the flat wire motor when running at high speed, avoiding local overheating of the winding, and extending the life of the flat wire motor.

In this embodiment, the stator is composed of a three-phase winding with a phase difference of 120 electrical degrees and a stator core 10. The structure of the stator winding 20 is in the stator core 10, each phase winding can include 3 parallel branches, and the 3 parallel branches use the central axis of the stator core 10 as the rotation axis, and the 3 parallel branches in the same-phase winding are rotationally symmetrical. When the stator is applied to a flat wire motor, the central axis can also refer to the rotor center line of the rotor in the flat wire motor. The rotational symmetry can be that a parallel branch in the same-phase winding is moved by a certain number of stator slots and coincides with other parallel branches in the same-phase winding.

The parallel branches in each phase winding in the stator can be connected in a star manner or a triangle manner, wherein each phase winding is composed of two parallel branches.

Each parallel branch includes a plurality of hairpin coils 21, and each stator slot 11 is provided with n layers of flat wire conductors of hairpin coils 21, where n is a positive integer. The hairpin coils 21 are formed of flat wire conductors, and the cross section of the flat wire conductors is rectangular, and are inserted into the stator slots 11.

3 and 4 , FIG. 3 is a schematic diagram of a structure of the hairpin coil in the stator shown in FIG. 1 , and FIG. 4 is another schematic diagram of the structure of the hairpin coil in the stator shown in FIG. 1 .

The hairpin coil 21 includes a first leg 211, a second leg 212, a connecting section 213, a first bending section 214 and a second bending section 215. The first leg 211 and the second leg 212 are arranged in parallel and are respectively inserted in the slot layers of different stator slots 11. The connecting section 213 is connected to one end of the first leg 211 and the second leg 212. The connecting section 213 can be U-shaped or V-shaped. The first bending section 214 is connected to the other end of the first leg 211, and the second bending section 215 is connected to the other end of the second leg 212. The first bending section 214 and the second bending section 215 are also connected to a welding end 216. Adjacent hairpin coils in the same parallel branch are connected to the welding ends 216 through a connecting line for conduction.

The pitch of the hairpin coil 21 is the number of stator slots spanned by its first leg 211 and second leg 212. The first leg 211 and second leg 212 are generally disposed in the stator slot 11, the connecting section 213 is located outside the stator slot 11 and disposed on one end surface of the stator core 10, and the first bending section 214, the second bending section 215 and the welding end 216 are located outside the stator slot 11 and disposed on the other end surface of the stator core 10.

In one embodiment, the hairpin coil 21 can be inserted into the stator slot 11 and then bent to form a first bending section 214 and a second bending section 215, wherein after the hairpin coil 21 is inserted into the stator slot 11, its connecting section 213 forms the wire insertion part of the stator winding 20, and the welding end 216 forms the welding part of the stator winding 20.

As shown in FIG4 , the bending directions of the first bending section 214 and the second bending section 215 of some hairpin coils 21 are parallel, which are used for reversing winding; as shown in FIG3 , the bending directions of the first bending section 214 and the second bending section 215 of the remaining hairpin coils 21 are symmetrically arranged, which are used for in-phase winding.

In the present application, n layers of hairpin coils 21 are provided in any stator slot 11, that is, each slot layer of the stator slot 11 is provided with a first leg 211 or a second leg 212 of the hairpin coil 21, and the hairpin coil 21 of each parallel branch traverses n slot layers in different stator slots 11, thereby eliminating the potential phase difference caused by the positions of multiple parallel branches in each phase winding in the stator slot.

Multiple parallel branches of the same phase traverse n slot layers in different stator slots, and the stator slots 11 occupied by each phase winding are rotationally symmetrical on the stator circumference. Therefore, the p branches of the same phase are completely symmetrical, and no circulating current occurs when the flat wire motor is operating normally, thereby reducing the copper loss of the motor and improving the motor efficiency.

In one embodiment, the hairpin coils 21 in the same stator slot 11 are in phase, so no interphase insulation paper is required between the first legs 211 or the second legs 212 of different layers in the same stator slot 11, which can reduce the insulation cost of the flat wire motor.

Each parallel branch includes a plurality of hairpin coils 21 connected by connecting wires, and each stator slot 11 is provided with n layers of flat wire conductors of the hairpin coils 21, where n is a positive integer, i.e., each slot layer in the stator slot 11 is provided with a flat wire conductor. The hairpin coils 21 are formed of flat wire conductors, and the cross section of the flat wire conductors is rectangular, and are inserted into the stator slots 11.

Furthermore, the voltage lead wire of any parallel branch is located at the 1st slot layer or the nth slot layer, and the neutral point lead wire of any parallel branch is located at the 1st slot layer or the nth slot layer. By concentrating the lead wire positions of the parallel branches, the axial and radial space of the winding can be reduced, thereby reducing the manufacturing difficulty of the flat wire motor.

Optionally, the number of rotor poles is 6 or 8, the number q of parallel branches included in each phase winding is 1 or 2, the number s of stator slots 11 is 54 or 72, and the number n of slot layers of stator slots 11 is 4, 6, 8 or 10; wherein, the winding method of the three-phase winding can be wave winding or stack winding, and the hairpin coil includes a U-type hairpin coil and an I-type hairpin coil.

Among them, the solid line represents the wiring method of the plug-in end, and the dotted line represents the wiring method of the welding end. U1 and U2 can be used as voltage lead wires or as neutral point lead wires, and X1 and X2 can be used as voltage lead wires or as neutral point lead wires. U1 and U2 are connected in parallel, and X1 and X2 are connected in parallel. Finally, they are connected through a bus bar to form a completed U-phase winding.

The U-phase winding, V-phase winding and W-phase winding are symmetrically and evenly distributed on the circumference of the stator core 10. In this embodiment, the V-phase winding and the W-phase winding can be obtained by rotating a plurality of stator slots 11 along the circumferential direction of the stator core 10 through the U-phase winding. The winding method of the V-phase winding and the W-phase winding will not be described in detail herein.

Specifically, in one embodiment, q is 2, n is 4, 6, 8 or 10, the hairpin coil pitch of any parallel branch in the first slot layer or the nth slot layer is 8 or 10; the hairpin coil pitch of any parallel branch from the 2nd layer to the n-1th layer is 9, and the welding pitch of any parallel branch from the 2nd slot layer to the n-1th slot layer is 9.

Take a 6-pole 54-slot flat wire motor as an example, wherein the number s of stator slots is 54, the number of rotor poles is 6, the number q of parallel branches included in each phase winding is 2, and the number n of slot layers of the stator slot 11 is 4.

Here, the number i(j) represents the jth slot layer in the i-th slot, for example, 1(1) represents the 1st slot layer of the 1st slot, and 7(2) represents the 2nd slot layer of the 7th slot.

In this embodiment, the first parallel branch of the U-phase winding has three winding modes.

In the first winding method, as shown in FIG5 , the first parallel branch of the U-phase winding is wound from the voltage lead-out line position U1 into the lead-out line from the neutral point lead-out line position X1. The slot numbers of the first parallel branch connected in series are: 1(4)→10(3)→19(4)→28(3)→37(4)→46(3)→1(2)→10(1)→19(2)→28(1)→37(2)→46(1)→ 38(1)→29(2)→20(1)→11(2)→2(3)→47(4)→3(4)→12(3)→21(4)→30(3)→39(4)→48(3)→3(2)→12(1)→21(2)→30(1)→39(2)→48(1)→2(1)→47(2)→38(3) →29(4)→20(3)→11(4).

In the second winding method, as shown in FIG6 , the first parallel branch of the U-phase winding is wound from the voltage lead-out line position U1 into the lead-out line from the neutral point lead-out line position X1. The slot numbers of the first parallel branch connected in series are: 3(4)→12(3)→21(4)→30(3)→39(4)→48(3)→3(2)→12(1)→21(2)→30(1)→39(2)→48(1)→ 38(1)→29(2)→20(1)→11(2)→2(1)→47(2)→38(3)→29(4)→20(3)→11(4)→2(3)→47(4)→1(4)→10(3)→19(4)→28(3)→37(4)→46(3)→1(2)→10(1)→19(2) →28(1)→37(2)→46(1).

In the third winding method, as shown in FIG7 , the first parallel branch of the U-phase winding is wound from the voltage lead-out line position U1 into the lead-out line from the neutral point lead-out line position X1. The slot numbers of the first parallel branch connected in series are: 1(4)→10(3)→19(4)→28(3)→37(4)→46(3)→1(2)→10(1)→19(2)→28(1)→37(2)→46(1)→ 38(1)→29(2)→20(1)→11(2)→2(1)→47(2)→38(3)→29(4)→20(3)→11(4)→2(3)→47(4)→3(4)→12(3)→21(4)→30(3)→39(4)→48(3)→3(2)→12(1)→21(2) →30(1)→39(2)→48(1).

In this embodiment, the second parallel branch of the U-phase winding has three winding modes.

In the first winding method, as shown in FIG8 , the second parallel branch of the U-phase winding is wound from the voltage lead-out line position U2 into the lead-out line from the neutral point lead-out line position X2. The slot numbers of the second parallel branch connected in series are: 1(1)→46(2)→37(1)→28(2)→19(1)→10(2)→1(3)→46(4)→37(3)→28(4)→19(3)→10(4)→ 2(4)→11(3)→20(4)→29(3)→38(4)→47(3)→2(2)→11(1)→20(2)→29(1)→38(2)→47(1)→3(1)→48(2)→39(1)→30(2)→21(1)→12(2)→3(3)→48(4)→39(3) →30(4)→21(3)→12(4).

In the second winding method, as shown in FIG9 , the second parallel branch of the U-phase winding is wound from the voltage lead-out line position U2 into the lead-out line from the neutral point lead-out line position X2. The slot numbers of the second parallel branch connected in series are: 3(1)→48(2)→39(1)→30(2)→21(1)→12(2)→3(3)→48(4)→39(3)→30(4)→21(3)→12(4)→ 2(4)→11(3)→20(4)→29(3)→38(4)→47(3)→2(2)→11(1)→20(2)→29(1)→38(2)→47(1)→1(1)→46(2)→37(1)→28(2)→19(1)→10(2)→1(3)→46(4)→37(3) →28(4)→19(3)→10(4).

The third winding method, as shown in FIG10 , is that the second parallel branch of the U-phase winding is wound from the voltage lead-out line position U2 to the neutral point lead-out line position X2. The slot numbers of the second parallel branch connected in series are: 28(4)→37(3)→46(4)→1(3)→10(4)→19(3)→28(2)→37(1)→46(2)→1(1)→10(2)→19(1) →11(1)→2(2)→47(1)→38(2)→29(1)→20(2)→11(3)→2(4)→47(3)→38(4)→29(3)→20(4)→30(4)→39(3)→48(4)→3(3)→12(4)→21(3)→30(2)→39(1)→48(2) →3(1)→12(2)→21(1).

Take a 6-pole 54-slot flat wire motor as an example, wherein the number s of stator slots is 54, the number of rotor poles is 6, the number q of parallel branches included in each phase winding is 2, and the number n of slot layers of the stator slot 11 is 6.

In this embodiment, the first parallel branch of the U-phase winding has three winding modes.

In the first winding method, as shown in FIG11 , the first parallel branch of the U-phase winding is wound from the voltage lead-out line position U1 into the lead-out line from the neutral point lead-out line position X1. The slot numbers of the first parallel branch connected in series are: 3(6)→12(5)→21(6)→30(5)→39(6)→48(5)→3(4)→12(3)→21(4)→30(3)→39(4)→48(3)→3(2)→12(1)→21(2)→30(1)→39(2)→48(1)→2(1)→47(2)→38(3)→ 29(4)→20(3)→11(4)→2(5)→47(6)→1(6)→10(5)→19(6)→28(5)→37(6)→46(5)→1(4)→10(3)→19(4)→28(3)→37(4)→46(3)→1(2)→10(1)→19(2)→28(1) →37(2)→46(1)→38(1)→29(2)→20(1)→11(2)→2(3)→47(4)→38(5)→29(6)→20(5)→11(6).

The second winding method, as shown in FIG12, is that the first parallel branch of the U-phase winding is wound from the voltage lead-out line position U1 into the lead-out line from the neutral point lead-out line position X1, and the slot numbers of the first parallel branch connected in series are: 3(6)→12(5)→21(6)→30(5)→39(6)→48(5)→3(4)→12(3)→21(4)→30(3)→39(4)→48(3)→3(2)→12(1)→21(2)→30(1)→39(2)→48(1)→38(1)→29(2)→20(1) →11(2)→2(1)→47(2)→38(3)→29(4)→20(3)→11(4)→2(3)→47(4)→38(5)→29(6)→20(5)→11(6)→2(5)→47(6)→1(6)→10(5)→19(6)→28(5)→37(6)→46(5) →1(4)→10(3)→19(4)→28(3)→37(4)→46(3)→1(2)→10(1)→19(2)→28(1)→37(2)→46(1).

The third winding method, as shown in FIG13 , is that the first parallel branch of the U-phase winding is wound from the voltage lead-out line position U1 into the lead-out line from the neutral point lead-out line position X1, and the slot numbers of the first parallel branch connected in series are: 1(6)→10(5)→19(6)→28(5)→37(6)→46(5)→1(4)→10(3)→19(4)→28(3)→37(4)→46(3)→1(2)→10(1)→19(2)→28(1)→37(2)→46(1)→38(1)→29(2)→20(1) →11(2)→2(1)→47(2)→38(3)→29(4)→20(3)→11(4)→2(3)→47(4)→38(5)→29(6)→20(5)→11(6)→2(5)→47(6)→3(6)→12(5)→21(6)→30(5)→39(6)→48(5) →3(4)→12(3)→21(4)→30(3)→39(4)→48(3)→3(2)→12(1)→21(2)→30(1)→39(2)→48(1).

In this embodiment, the second parallel branch of the U-phase winding has three winding modes.

In the first winding method, as shown in FIG14 , the second parallel branch of the U-phase winding is wound from the voltage lead-out line position U2 into the lead-out line from the neutral point lead-out line position X2. The slot numbers of the second parallel branch connected in series are: 1(1)→46(2)→37(1)→28(2)→19(1)→10(2)→1(3)→46(4)→37(3)→28(4)→19(3)→10(4)→1(5)→46(6)→37(5)→28(6)→19(5)→10(6)→2(6)→11(5)→20(6)→ 29(5)→38(6)→47(5)→2(4)→11(3)→20(4)→29(3)→38(4)→47(3)→2(2)→11(1)→20(2)→29(1)→38(2)→47(1)→3(1)→48(2)→39(1)→30(2)→21(1)→12(2 )→3(3)→48(4)→39(3)→30(4)→21(3)→12(4)→3(5)→48(6)→39(5)→30(6)→21(5)→12(6).

In the second winding method, as shown in FIG15 , the second parallel branch of the U-phase winding is wound from the voltage lead-out line position U2 into the neutral point lead-out line position X2. The slot numbers of the second parallel branch connected in series are: 3(1)→48(2)→39(1)→30(2)→21(1)→12(2)→3(3)→48(4)→39(3)→30(4)→21(3)→12(4)→3(5)→48(6)→39(5)→30(6)→21(5)→12(6)→2(6)→11(5)→20(6)→ 29(5)→38(6)→47(5)→2(4)→11(3)→20(4)→29(3)→38(4)→47(3)→2(2)→11(1)→20(2)→29(1)→38(2)→47(1)→1(1)→46(2)→37(1)→28(2)→19(1)→10(2 )→1(3)→46(4)→37(3)→28(4)→19(3)→10(4)→1(5)→46(6)→37(5)→28(6)→19(5)→10(6).

In the third winding method, as shown in FIG16 , the second parallel branch of the U-phase winding is wound from the voltage lead-out line position U2 into the lead-out line from the neutral point lead-out line position X2. The slot numbers of the second parallel branch connected in series are: 28(6)→37(5)→46(6)→1(5)→10(6)→19(5)→28(4)→37(3)→46(4)→1(3)→10(4)→19(3)→28(2)→37(1)→46(2)→1(1)→10(2)→19(1)→11(1)→2(2)→47(1)→ 38(2)→29(1)→20(2)→11(3)→2(4)→47(3)→38(4)→29(3)→20(4)→11(5)→2(6)→47(5)→38(6)→29(5)→20(6)→30(6)→39(5)→48(6)→3(5)→12(6)→21(5) →30(4)→39(3)→48(4)→3(3)→12(4)→21(3)→30(2)→39(1)→48(2)→3(1)→12(2)→21(1).

In another embodiment, q is 1, n is 4 or 8, and the hairpin coil pitch combination of any parallel branch in the first slot layer or the nth slot layer is 7, 8, 10, 8, 9, 10, or 8, 10, 11; and the hairpin coil pitch of any parallel branch from the 2nd layer to the n-1th layer is 9, and the welding pitch of any parallel branch from the 2nd slot layer to the n-1th slot layer is 9.

Take a 6-pole 54-slot flat wire motor as an example, wherein the number s of stator slots is 54, the number of rotor poles is 6, the number q of parallel branches included in each phase winding is 1, and the number n of slot layers of the stator slot 11 is 4.

In this embodiment, the U-phase winding has multiple winding methods.

In the first winding method, as shown in Figure 17, the U-phase winding is wound from the voltage lead-out line position U to the neutral point lead-out line position X. The slot numbers of the U-phase winding connected in series are: 1(1)→46(2)→37(1)→28(2)→19(1)→10(2)→1(3)→46(4)→37(3)→28(4)→19(3)→10(4)→2(4)→11(3)→20(4)→29(3)→38(4)→47(3)→2(2)→11(1)→20(2)→29(1)→38(2)→47(1)→3(1)→48(2)→39(1)→30(2)→21(1)→12(2)→3(3)→4 8(4)→39(3)→30(4)→21(3)→12(4)→3(4)→12(3)→21(4)→30(3)→39(4)→48(3)→3(2)→12(1)→21(2)→30(1)→39(2)→48(1)→38(1)→29(2)→20(1)→11(2) →2(1)→47(2)→38(3)→29(4)→20(3)→11(4)→2(3)→47(4)→1(4)→10(3)→19(4)→28(3)→37(4)→46(3)→1(2)→10(1)→19(2)→28(1)→37(2)→46(1).

The second winding method, as shown in FIG18, is that the U-phase winding is wound from the voltage lead-out line position U to the neutral point lead-out line position X. The slot numbers of the U-phase winding connected in series are: 1(4)→10(3)→19(4)→28(3)→37(4)→46(3)→1(2)→10(1)→19(2)→28(1)→37(2)→46(1)→38(1)→29(2)→20(1)→11(2)→2(1)→47(2)→38(3)→29(4)→20(3)→11(4)→2(3)→47(4)→3(4)→12(3)→21(4)→30(3)→39(4)→48(3)→3(2)→1 2(1)→21(2)→30(1)→39(2)→48(1)→1(1)→46(2)→37(1)→28(2)→19(1)→10(2)→1(3)→46(4)→37(3)→28(4)→19(3)→10(4)→2(4)→11(3)→20(4)→29(3) →38(4)→47(3)→2(2)→11(1)→20(2)→29(1)→38(2)→47(1)→3(1)→48(2)→39(1)→30(2)→21(1)→12(2)→3(3)→48(4)→39(3)→30(4)→21(3)→12(4).

The third winding method, as shown in Figure 19, is that the U-phase winding is wound from the voltage lead-out line position U to the neutral point lead-out line position X. The slot numbers of the U-phase winding connected in series are: 3(4)→12(3)→21(4)→30(3)→39(4)→48(3)→3(2)→12(1)→21(2)→30(1)→39(2)→48(1)→38(1)→29(2)→20(1)→11(2)→2(1)→47(2)→38(3)→29(4)→20(3)→11(4)→2(3)→47(4)→1(4)→10(3)→19(4)→28(3)→37(4)→46(3)→1(2→1 0(1)→19(2)→28(1)→37(2)→46(1)→3(1)→48(2)→39(1)→30(2)→21(1)→12(2)→3(3)→48(4)→39(3)→30(4)→21(3)→12(4)→2(4)→11(3)→20(4)→29(3) →38(4)→47(3)→2(2)→11(1)→20(2)→29(1)→38(2)→47(1)→1(1)→46(2)→37(1)→28(2)→19(1)→10(2)→1(3)→46(4)→37(3)→28(4)→19(3)→10(4).

In another embodiment, q is 1, n is 6 or 10, and the hairpin coil pitch combination of any parallel branch in the first slot layer or the nth slot layer is 8, 9, 10, 7, 8, 8, 10, 11, or 7, 8, 10; the hairpin coil pitch of any parallel branch from the 2nd layer to the n-1th layer is 9, and the welding pitch of any parallel branch from the 2nd slot layer to the n-1th slot layer is 9.

Take a 6-pole 54-slot flat wire motor as an example, wherein the number s of stator slots is 54, the number of rotor poles is 6, the number q of parallel branches included in each phase winding is 1, and the number n of slot layers of the stator slot 11 is 6.

In this embodiment, the U-phase winding has multiple winding methods.

In the first winding method, as shown in Figure 20, the U-phase winding is wound from the voltage lead-out line position U to the neutral point lead-out line position X. The slot numbers of the U-phase winding connected in series are: 3(1)→48(2)→39(1)→30(2)→21(1)→12(2)→3(3)→48(4)→39(3)→30(4)→21(3)→12(4)→3(5)→48(6)→39(5)→30(6)→21(5)→12(6)→2(6)→11(5 )→20(6)→29(5)→38(6)→47(5)→2(4)→11(3)→20(4)→29(3)→38(4)→47(3)→2(2)→11(1)→20(2)→29(1)→38(2)→47(1)→1(1)→46(2)→37(1)→28(2)→19(1 )→10(2)→1(3)→46(4)→37(3)→28(4)→19(3)→10(4)→1(5)→4 6(6)→37(5)→28(6)→19(5)→10(6)→3(6)→12(5)→21(6)→30(5)→39(6)→48(5)→3(4)→12(3)→21(4)→30(3)→39(4)→48(3)→3(2)→12(1)→21(2)→30(1)→ 39(2)→48(1)→38(1)→29(2)→20(1)→11(2)→2(1)→47(2)→38( 3)→29(4)→20(3)→11(4)→2(3)→47(4)→38(5)→29(6)→20(5)→11(6)→2(5)→47(6)→1(6)→10(5)→19(6)→28(5)→37(6)→46(5)→1(4)→10(3)→19(4)→28( 3)→37(4)→46(3)→1(2)→10(1)→19(2)→28(1)→37(2)→46(1).

The second winding method, as shown in Figure 21, is that the U-phase winding is wound from the voltage lead-out line position U to the neutral point lead-out line position X. The slot numbers of the U-phase winding connected in series are: 1(6)→10(5)→19(6)→28(5)→37(6)→46(5)→1(4)→10(3)→19(4)→28(3)→37(4)→46(3)→1(2)→10(1)→19(2)→28(1)→37(2)→46(1)→38(1)→29( 2)→20(1)→11(2)→2(1)→47(2)→38(3)→29(4)→20(3)→11(4)→2(3)→47(4)→38(5)→29(6)→20(5)→11(6)→2(5)→47(6)→3(6)→12(5)→21(6)→30(5)→39( 6)→48(5)→3(4)→12(3)→21(4)→30(3)→39(4)→48(3)→3(2)→1 2(1)→21(2)→30(1)→39(2)→48(1)→3(1)→48(2)→39(1)→30(2)→21(1)→12(2)→3(3)→48(4)→39(3)→30(4)→21(3)→12(4)→3(5)→48(6)→39(5)→30(6)→ 21(5)→12(6)→2(6)→11(5)→20(6)→29(5)→38(6)→47(5)→2(4 )→11(3)→20(4)→29(3)→38(4)→47(3)→2(2)→11(1)→20(2)→29(1)→38(2)→47(1)→1(1)→46(2)→37(1)→28(2)→19(1)→10(2)→1(3)→46(4)→37(3)→28(4 )→19(3)→10(4)→1(5)→46(6)→37(5)→28(6)→19(5)→10(6).

The third winding method, as shown in Figure 22, is that the U-phase winding is wound from the voltage lead-out line position U to the neutral point lead-out line position X. The slot numbers of the U-phase winding connected in series are: 1(1)→46(2)→37(1)→28(2)→19(1)→10(2)→1(3)→46(4)→37(3)→28(4)→19(3)→10(4)→1(5)→46(6)→37(5)→28(6)→19(5)→10(6)→2(6)→11(5 )→20(6)→29(5)→38(6)→47(5)→2(4)→11(3)→20(4)→29(3)→38(4)→47(3)→2(2)→11(1)→20(2)→29(1)→38(2)→47(1)→3(1)→48(2)→39(1)→30(2)→21(1 )→12(2)→3(3)→48(4)→39(3)→30(4)→21(3)→12(4)→3(5)→4 8(6)→39(5)→30(6)→21(5)→12(6)→3(6)→12(5)→21(6)→30(5)→39(6)→48(5)→3(4)→12(3)→21(4)→30(3)→39(4)→48(3)→3(2)→12(1)→21(2)→30(1)→ 39(2)→48(1)→38(1)→29(2)→20(1)→11(2)→2(1)→47(2)→38( 3)→29(4)→20(3)→11(4)→2(3)→47(4)→38(5)→29(6)→20(5)→11(6)→2(5)→47(6)→1(6)→10(5)→19(6)→28(5)→37(6)→46(5)→1(4)→10(3)→19(4)→28( 3)→37(4)→46(3)→1(2)→10(1)→19(2)→28(1)→37(2)→46(1).

In another embodiment, the number n of slot layers of the stator slots 11 is an odd number, which may be 5 or 7, the number q of parallel branches included in each phase winding is an even number, which may be 2 or 4, and the number s of the stator slots may be 72.

Optionally, the hairpin coil pitch of the parallel branch in the first slot layer is 7 and/or 13, the hairpin coil pitch of the parallel branch in the nth slot layer is 7 and/or 13, the welding pitch of the parallel branch in the first slot layer or the nth slot layer is 13, and the winding method of the winding is wave winding. The hairpin coil pitch of any parallel branch between the second slot layer and the n-1th slot layer is 12.

Take a 6-pole 72-slot flat wire motor as an example, wherein the number of stator slots s is 72, the number of rotor poles is 6, the number of parallel branches included in each phase winding q is 2, the number of slot layers n of the stator slot 11 is 5, the number of slots per pole of the flat wire motor is 4, and the wave winding method is adopted. Only 6 types of hairpin coils 21 are required for the stator winding 20 of this embodiment.

As shown in FIG23 , the first parallel branch of the U-phase winding is wound from the voltage lead-out line position U1 into the neutral point lead-out line position X1. The slot numbers of the first parallel branch connected in series are: 1(5)→13(4)→25(5)→37(4)→49(5)→61(4)→1(3)→13(2)→25(3)→37(2)→49(3)→61(2)→1(1)→14(1)→25(2)→38(1)→49(2)→62(1)→50(2)→38(3)→26(2)→14(3)→2(2)→62(3)→50( 4)→38(5)→26(4)→14(5)→2(4)→62(5)→3(5)→15(4)→27(5)→39(4)→51(5)→63(4)→3(3)→15(2)→27(3)→39(2)→51(3)→63(2)→3(1)→16(1)→27(2)→40( 1)→51(2)→64(1)→52(2)→40(3)→28(2)→16(3)→4(2)→64(3)→52(4)→40(5)→28(4)→16(5)→4(4)→64(5).

As shown in FIG. 24 , the second parallel branch of the U-phase winding is wound from the voltage lead-out line position U2 into the neutral point lead-out line position X2. The slot numbers through which the second parallel branch is connected in series are: 4(5)→16(4)→28(5)→40(4)→52(5)→64(4)→4(3)→16(2)→28(3)→40(2)→52(3)→64(2)→4(1)→63(1)→52(2)→39(1)→28(2)→15(1)→3(2)→63(3)→51(2)→39(3)→27(2)→15(3)→3(4 )→63(5)→51(4)→39(5)→27(4)→15(5)→2(5)→14(4)→26(5)→38(4)→50(5)→62(4)→2(3)→14(2)→26(3)→38(2)→50(3)→62(2)→2(1)→61(1)→50(2)→37(1 )→26(2)→13(1)→1(2)→61(3)→49(2)→37(3)→25(2)→13(3)→1(4)→61(5)→49(4)→37(5)→25(4)→13(5).

The starting and ending slot numbers of the two parallel branches are distributed as follows: U1 corresponds to 1 (5), X1 corresponds to 64 (5); U2 corresponds to 4 (5), X2 corresponds to 13 (5). U1 and U2 are connected in parallel, X1 and X2 are connected in parallel, and finally connected through a bus bar to form a complete U-phase winding.

The hairpin coil pitches of the first parallel branch are 11, 12 and 13, the hairpin coil pitches of the second parallel branch are 11, 12 and 13, and the welding pitches are 13 and 12.

Optionally, the hairpin coil pitch of the parallel branch in the first slot layer is 13 and/or 15, the hairpin coil pitch of the parallel branch in the nth slot layer is 13 and/or 15, the welding pitch of the parallel branch in the first slot layer or the nth slot layer is 11 and/or 13, and the winding method of the winding is stacked winding. The hairpin coil pitch of any parallel branch between the second slot layer and the n-1th slot layer is 12.

Take a 6-pole 72-slot flat wire motor as an example, wherein the number of stator slots s is 72, the number of rotor poles is 6, the number of parallel branches included in each phase winding q is 2, the number of slot layers n of the stator slot 11 is 5, the number of slots per pole of the flat wire motor is 4, and the stacking winding method is adopted. Only 6 types of hairpin coils 21 are required for the stator winding 20 of this embodiment.

As shown in FIG25 , the first parallel branch of the U-phase winding is wound from the voltage lead-out line position U1 into the lead-out line from the neutral point lead-out line position X1. The slot numbers through which the first parallel branch is connected in series are: 1(5)→13(4)→1(3)→13(2)→1(1)→14(1)→26(2)→14(3)→26(4)→14(5)→27(5)→39(4)→27(3)→39(2)→27(1)→40(1)→52(2)→40(3)→52(4)→40(5)→25(5)→37(4)→25(3)→37(2)→25 (1)→38(1)→50(2)→38(3)→50(4)→38(5)→51(5)→63(4)→51(3)→63(2)→51(1)→64(1)→4(2)→64(3)→4(4)→64(5)→49(5)→61(4)→49(3)→61(2)→49(1)→6 2(1)→2(2)→62(3)→2(4)→62(5)→3(5)→15(4)→3(3)→15(2)→3(1)→16(1)→28(2)→16(3)→28(4)→16(5).

As shown in FIG26 , the second parallel branch of the U-phase winding is wound from the voltage lead-out line position U2 into the lead-out line from the neutral point lead-out line position X2. The slot numbers through which the second parallel branch is connected in series are: 4(5)→16(4)→4(3)→16(2)→4(1)→15(1)→27(2)→15(3)→27(4)→15(5)→2(5)→14(4)→2(1)→13(1)→25(2)→13(3)→25(4)→13(5)→28(5)→40(4)→28(3)→40(2)→28(1)→39(1) →51(2)→39(3)→51(4)→39(5)→26(5)→38(4)→26(3)→38(2)→26(1)→37(1)→49(2)→37(3)→49(4)→37(5)→52(5)→64(4)→52(3)→64(2)→52(1)→63(1)→3 (2)→63(3)→3(4)→63(5)→50(5)→62(4)→50(3)→62(2)→50(1)→61(1)→1(2)→61(3)→1(4)→61(5).

The starting slot and ending slot numbers of the two winding branches are distributed as follows: U1 corresponds to 1 (5), X1 corresponds to 16 (5); U2 corresponds to 4 (5), X2 corresponds to 61 (5). U1 and U2 are connected in parallel, X1 and X2 are connected in parallel, and finally connected through a bus bar to form a complete U-phase winding.

The coil pitches of the first parallel branch are 12, 13 and 15, the coil pitches of the second parallel branch are 12, 13 and 15, and the welding pitches are 11, 12 and 13.

The embodiment of the present application also provides a power assembly, which includes a reducer and the above-mentioned flat wire motor. The flat wire motor and the reducer are in transmission connection. Specifically, the driving shaft of the flat wire motor and the input shaft of the reducer can be connected in transmission through a transmission member such as a coupling to output the driving force from the flat wire motor to the reducer.

The vehicle provided in the embodiment of the present application includes the above-mentioned powertrain, which is arranged in the vehicle and provides running power for the vehicle. Specifically, in the present embodiment, the vehicle can be a new energy vehicle driven by electric energy. Among them, the new energy vehicle can be a hybrid electric vehicle, a pure electric vehicle or a fuel cell electric vehicle, etc., or it can be a vehicle that uses a high-efficiency energy storage device such as a supercapacitor, a flywheel battery or a flywheel energy storage device as a source of electric energy.

Different from the prior art, the present application discloses a vehicle, a powertrain, a flat wire motor and a stator thereof. By making the multiple parallel branches of each phase winding rotationally symmetrical in the circumferential direction, the magnetic field distribution of the multiple parallel branches in each phase winding is the same, and the potential is balanced, thereby avoiding the circulation generated between the parallel branches, thereby greatly reducing the additional AC copper loss at high frequency, improving the efficiency of the flat wire motor at high speed, avoiding local overheating of the winding, and extending the life of the flat wire motor; and the hairpin coil of each parallel branch traverses N slot layers in different stator slots, thereby eliminating the potential phase difference caused by the position of the multiple parallel branches in each phase winding in the stator slot.

The above descriptions are merely embodiments of the present application and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims (9)

1. A stator of a flat wire motor, characterized by comprising: A stator core, wherein the inner wall of the stator core is uniformly provided with s stator slots along its circumference, and the stator slots are divided into n slot layers along the radial direction of the stator core; The stator winding comprises three-phase windings arranged in a periodic manner in sequence along the circumferential direction of the stator core, each phase winding comprises q parallel branches, the q parallel branches are rotationally symmetrical in the circumferential direction, each of the parallel branches comprises a plurality of hairpin coils with different pitches, each of the stator slots is provided with n layers of flat wire conductors of the hairpin coils, and the hairpin coils of each parallel branch traverse n slot layers in different stator slots; wherein n is an odd number, and s and q are both positive integers. 2. The stator according to claim 1 is characterized in that the number q of parallel branches included in each phase winding is 2 or 4, the number s of the stator slots is 72, and the number n of slot layers of the stator slots is 5 or 7. 3. The stator according to claim 2 is characterized in that the pitch of the hairpin coils of the parallel branch in the first slot layer is 7 and/or 13, the pitch of the hairpin coils of the parallel branch in the nth slot layer is 7 and/or 13, the welding pitch of the parallel branch in the first slot layer or the nth slot layer is 13, and the winding method of the winding is wave winding. 4. The stator according to claim 2 is characterized in that the pitch of the hairpin coils of the parallel branch in the first slot layer is 13 and/or 15, the pitch of the hairpin coils of the parallel branch in the nth slot layer is 13 and/or 15, the welding pitch of the parallel branch in the first slot layer or the nth slot layer is 11 and/or 13, and the winding method of the winding is stacked winding. 5. The stator according to claim 3 or 4, characterized in that the pitch of the hairpin coil between the 2nd slot layer and the n-1th slot layer of any of the parallel branches is 12. 6. The stator according to claim 1 is characterized in that the voltage lead wire of any of the parallel branches is located at the 1st slot layer or the nth slot layer, and the neutral point lead wire of any of the parallel branches is located at the 1st slot layer or the nth slot layer. 7. A flat wire motor, comprising a rotor and the stator according to any one of claims 1 to 6, wherein the rotor is arranged in a space surrounded by an inner wall of the stator core. 8. A power assembly, characterized by comprising a reducer and the flat wire motor according to claim 7, wherein the flat wire motor is drivingly connected to the reducer. 9. A vehicle, characterized by comprising the powertrain according to claim 8.