CN115765254A

CN115765254A - Stator, flat wire motor, power assembly and vehicle

Info

Publication number: CN115765254A
Application number: CN202211252007.3A
Authority: CN
Inventors: 赵素珍; 巫存; 米泽银; 俞东; 岳卫东
Original assignee: Zhejiang Lingsheng Power Technology Co Ltd
Current assignee: Zhejiang Lingsheng Power Technology Co Ltd
Priority date: 2022-10-10
Filing date: 2022-10-10
Publication date: 2023-03-07

Abstract

The application discloses stator, flat wire motor, power assembly and vehicle. The stator includes: a plurality of stator slots are uniformly distributed on the inner wall of the stator core along the circumferential direction; each phase winding comprises a plurality of parallel branches which are rotationally symmetrical in the circumferential direction, each parallel branch comprises a plurality of hairpin coils which are connected through connecting wires and have different pitches, N layers of hairpin coils are arranged in any stator slot, and the hairpin coils of each parallel branch traverse N slot layers in different stator slots; when N = (2n + 1) × 2, the total combination of the slot layers occupied by each parallel branch in each stator slot is 2N, or 2N, 2N-1, 2N-2; when N =2N × 2, the total number of the slot layers occupied by each parallel branch in each stator slot is 2N, 2N-1, or 2N, 2N-1, 2N-2; when N =2n +1, the total number of the slot layers occupied by each parallel branch in each stator slot is N, N-1, or N, N-1, N-2. Through the mode, the stator provided by the application can avoid generating circulation, the manufacturing cost is reduced, and the processing and manufacturing efficiency is improved.

Description

Stator, flat wire motor, power assembly and vehicle

Technical Field

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

Background

With the rapid popularization of new energy automobiles, new energy electric automobiles are more and more popularized, the market demand on the performance of a power system of the electric automobiles is continuously improved, a main drive motor is a power output part of the power system and is one of the most core parts of the electric automobiles, and the performance index requirements of the main drive motor are higher and higher, such as high power density and torque density, small volume and light weight. With the development of the flat wire process, the motor of the electric automobile gradually adopts a flat wire winding, and the flat wire winding can improve the slot filling rate of the stator and further improve the power density, efficiency and heat conductivity of the motor.

The existing motor mainly adopts a wave winding or lap winding structure, and the alternating current resistance of the motor can be effectively reduced by designing flat wire conductors in the winding structure into multiple layers. However, the winding structure is not wired in the same manner as the number of layers of the flat wire conductors increases. The three-phase winding of the existing winding structure is generally provided with a plurality of parallel branches, circulation currents are easily generated among the branches, the types of the line types of the hairpin coils are various, the production process is complex, and the manufacturing cost is high.

Disclosure of Invention

The application mainly provides a stator, a flat wire motor, a power assembly and a vehicle, and aims to solve the problems that circulation currents are easily generated among a plurality of parallel branches of a three-phase winding in the flat wire motor, and the production process is complex and the manufacturing cost is high due to the fact that the types of the wire types of the hairpin coils are multiple.

In order to solve the technical problem, the application adopts a technical scheme that: a stator of a flat wire motor is provided. The stator of the flat wire motor includes: the stator comprises a stator core, wherein a plurality of stator slots are uniformly distributed on the inner wall of the stator core along the circumferential direction of the stator core; the stator winding comprises three-phase windings, each phase winding comprises a plurality of parallel branches, the parallel branches are rotationally symmetrical in the circumferential direction, each parallel branch comprises a plurality of hairpin coils which are connected through connecting wires and have different pitches, N layers of hairpin coils are arranged in any stator slot, the hairpin coils of each parallel branch traverse N slot layers in different stator slots, and the three-phase windings are sequentially arranged in a periodic manner along the circumferential direction of the stator core; when N = (2n + 1) × 2, the total number of slot layer groups occupied by each parallel branch at each stator slot is 2N, or 2N, 2N-1, 2N-2; when N =2N × 2, the total number of slot layer occupied by each parallel branch in each stator slot is 2N, 2N-1, or 2N, 2N-1, 2N-2; when N =2n +1, the total number of the groove layers occupied by each parallel branch in each stator groove is N, N-1, or N, N-1, N-2; wherein N is a positive integer and is greater than or equal to 4, and the total number of slot layers of each parallel branch in each stator slot is also a positive integer.

In some embodiments, when the total number of slot layers occupied by each of the parallel branches in the stator slot is 1, the position of the one slot layer is the first layer or the Nth layer of the stator slot;

when the total number of the slot layers occupied by each parallel branch in the stator slot is 2, the 2 slot layers are adjacently arranged in the stator slot, or the 2 slot layers are respectively a first layer and an Nth layer in the stator slot;

when the total number of the slot layers occupied by each parallel branch in the stator slot is 3, two of the 3 slot layers are arranged adjacently, and the position of the rest one slot layer is the first layer or the Nth layer of the stator slot and is separated from the other two slot layers by four slot layers;

when the total number of the slot layers occupied by each parallel branch in the stator slots is 4, the 4 slot layers are divided into two groups, each group is separated by four slot layers, and each group comprises two adjacent slot layers.

In some embodiments, each phase winding includes three parallel legs.

In some embodiments, the number of stator slots is 54 or 72.

In some embodiments, the combination of pitches of the hairpin coils in each of the parallel branches is 8, 9, 11.

In some embodiments, the hairpin pitch of each of the parallel branches at the same slot level is 9.

In some embodiments, the hairpin pitch of each of the parallel branches at the first or nth slot layer is 8 or 8, 11.

In some embodiments, the inlet end of each parallel branch is on the Nth layer of the groove layer, and the outlet end is on the (N-1) th layer of the groove layer; or

And the wire inlet end and the wire outlet end of each parallel branch are arranged on the first groove layer and the Nth groove layer.

In some embodiments, the bond pitch between the hairpin coils in each of the parallel legs is 9.

In order to solve the above technical problem, another technical solution adopted by the present application is: a flat wire motor is provided. The flat wire motor comprises a rotor and the stator, wherein the rotor is arranged in a space formed by enclosing of the inner wall of the stator iron core.

In order to solve the technical problem, the other technical scheme adopted by the application is as follows: a powertrain is provided. The power assembly comprises a speed reducer and the flat wire motor, and the flat wire motor is in transmission connection with the speed reducer.

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

The beneficial effect of this application is: being different from the situation of the prior art, the application discloses a stator, a flat wire motor, a power assembly and a vehicle. The magnetic field distribution of the parallel branches in each phase of winding is the same and the potential is balanced by the rotation symmetry of the parallel branches in the circumferential direction, so that the circulation generated among the parallel branches is avoided, the additional alternating current copper consumption under high frequency can be greatly reduced, the efficiency of the flat wire motor in high-speed operation is improved, the local over-temperature of the winding is avoided, and the service life of the flat wire motor is prolonged; and the hairpin coil of each parallel branch traverses N slot layers in different stator slots, so that the potential phase difference caused by the positions of a plurality of parallel branches in each phase winding in the stator slots can be eliminated, the linear type of the hairpin coil is reduced by limiting the number N of slot layers in the stator slots and the total number of slot layers occupied by each parallel branch in each stator slot, the manufacturing die of the flat wire motor is reduced, the manufacturing cost is reduced, and the processing and manufacturing efficiency can be effectively improved.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the embodiments or the prior art descriptions will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without inventive efforts, wherein:

fig. 1 is a schematic structural diagram of an embodiment of a stator of a flat-wire motor provided in the present application;

fig. 2 is a schematic view of a stator core structure of the stator shown in fig. 1;

FIG. 3 is a schematic circuit diagram of the stator of FIG. 1 in which the parallel branches of each phase winding are connected in a star configuration;

fig. 4 is a schematic circuit diagram of a delta connection of parallel branches in each phase winding of the stator shown in fig. 1;

FIG. 5 is a schematic view of the hairpin coil structure in the stator shown in FIG. 1;

fig. 6 is a schematic view of a slot layer structure of stator slots in the stator core shown in fig. 2;

fig. 7 is a schematic diagram of a first winding of a U-phase winding in a 6-pole 54-slot flat-wire motor provided by the present application, where the number of slot layers is 4;

fig. 8 is a schematic diagram of a second winding of the U-phase winding in a 6-pole 54-slot flat-wire motor provided by the present application, where the number of slot layers is 4;

fig. 9 is a winding diagram of a U-phase winding of a 6-pole 54-slot flat-wire motor provided by the present application, where the number of slot layers is 5;

fig. 10 is a schematic diagram of a first winding of a U-phase winding in a 6-pole 54-slot flat-wire motor provided by the present application, where the number of slot layers is 6;

fig. 11 is a schematic diagram of a second winding of a U-phase winding in a 6-pole 54-slot flat-wire motor provided by the present application, where the number of slot layers is 6;

fig. 12 is a winding schematic diagram of a U-phase winding of a 6-pole 54-slot flat-wire motor provided in the present application when the number of slot layers is 7;

fig. 13 is a winding schematic diagram of a U-phase winding of a 6-pole 54-slot flat-wire motor provided in the present application when the number of slot layers is 8;

fig. 14 is a winding diagram of a U-phase winding of a 6-pole 54-slot flat-wire motor provided by the present application, where the number of slot layers is 9;

fig. 15 is a winding diagram of a U-phase winding of a 6-pole 54-slot flat-wire motor provided by the present application when the number of slot layers is 10.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The terms "first", "second" and "third" in the embodiments of the present application are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," or "third" may explicitly or implicitly include at least one of the feature. In the description of the present application, "plurality" means at least two, e.g., two, three, etc., unless explicitly specified otherwise. Furthermore, the terms "include" and "have," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements but may alternatively include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.

For convenience of understanding, terms appearing in the present application will be explained below.

A stator: refers to the stationary part of the machine that acts to generate a rotating magnetic field.

A rotor: refers to a rotating part in the motor, and the function of the rotating part is to realize the conversion of electric energy and mechanical energy.

Pitch: the distance spanned by two element sides of the same element in the motor winding on the surface of the armature is generally expressed by the number of stator slots formed in the stator core.

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

The embodiment of the application provides a flat wire motor, this flat wire motor includes rotor and stator, and the rotor is located in the space that the stator core inner wall of this stator encloses and establishes the formation, and every utmost point every looks slot number of this flat wire motor can be 3, and the pole number of rotor is the even number, and the slot pole cooperation of this flat wire motor can be 6 utmost point 54 grooves, 8 utmost point 72 grooves, 10 utmost point 90 grooves, 12 utmost point 108 grooves etc. this application does not do not specifically to limit to 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 fig. 2, the inner wall of the stator core 10 is provided with a plurality of stator slots 11 uniformly distributed along the circumferential direction, the number of the stator slots 11 is a multiple of 3, for example, the number of the stator slots 11 may be 54 or 72, any one of the stator slots 11 extends in the axial direction of the stator core 10 and penetrates through the inner wall of the stator core 10 along the axial direction of the stator core 10, and the stator slots 11 are further divided into N layers along the radial direction of the stator core 10.

The stator winding 20 includes three-phase windings, which are U-phase windings, V-phase windings, and W-phase windings, that are periodically arranged in sequence in the circumferential direction of the stator core 10. Each phase winding comprises a plurality of parallel branches which are rotationally symmetrical in the circumferential direction; for example, each phase winding includes three parallel branches, which are rotationally symmetric in the circumferential direction of the stator core 10, or each phase winding may further include two or four parallel branches.

The magnetic field distribution of the parallel branches in each phase of winding is the same and the potential is balanced by limiting the circumferential rotational symmetry of the parallel branches in each phase of winding, so that the circulation generated among the parallel branches is avoided, the additional alternating current copper consumption under high frequency can be greatly reduced, the efficiency of the flat wire motor in high-speed operation is improved, the local over-temperature of the winding is avoided, and the service life of the flat wire motor is prolonged.

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

Referring to fig. 3, fig. 3 is a schematic circuit diagram of a stator shown in fig. 1 in which parallel branches of each phase winding are connected in a star connection, where each phase winding is composed of 3 parallel branches.

Alternatively, referring to fig. 4, fig. 4 is a schematic circuit diagram of a circuit in which parallel branches in each phase of winding in the stator shown in fig. 1 are connected in a delta manner, where each phase of winding is formed by 3 parallel branches.

Referring to fig. 1, fig. 2 and fig. 5 in combination, fig. 5 is a schematic structural diagram of the hairpin coil in the stator shown in fig. 1.

Each parallel branch comprises a plurality of hairpin coils 21 which are connected by connecting lines and have different pitches, each hairpin coil 21 is formed by a flat wire conductor, the cross section of each flat wire conductor is rectangular and is inserted in the stator slot 11, each hairpin coil 21 comprises two straight line segments 211 arranged in parallel and a connecting segment 212 for connecting the two straight line segments 211, each straight line segment 211 is inserted in the stator slot 11, each connecting segment 212 is arranged outside the stator slot 11, each connecting segment 212 can be U-shaped or V-shaped, the pitch of each hairpin coil is the number of stator slots spanned by the two straight line segments 211 arranged in parallel of the hairpin coil 21, and the welding pitch between the hairpin coils 21 is the number of stator slots spanned by the adjacent straight line segments 211 of the two adjacent hairpin coils 21.

The hairpin coil 21 further includes a bending section 213 connected to the straight section 211, the bending section 213 is also disposed outside the stator slot 11 and is disposed on the end surface of the stator core 10 together with the connection section 212, and adjacent bending sections 213 of adjacent hairpin coils in the same parallel branch are connected and conducted through a connection line.

In an embodiment, the hairpin coil 21 may be inserted into the stator slot 11 and then the hairpin coil 21 is bent to form the bent portion 223, wherein after the hairpin coil 21 is inserted into the stator slot 11, the connecting section 212 forms a plug end of the stator winding 20, and the bent portion 223 forms a welding end of the stator winding 20.

In the present application, N layers of hairpin coils 21 are disposed in any stator slot 11, that is, each slot layer of the stator slot 11 is provided with a straight line segment 211 of a hairpin coil 21, and the hairpin coil 21 of each parallel branch traverses N slot layers in different stator slots 11, so that a potential phase difference caused by the positions of multiple parallel branches in each phase winding in the stator slots can be eliminated; where N is a positive integer and is greater than or equal to 4, for example N can be 4, 5, 6, 7, 8, 9 or 10.

For example, if N is 4, each stator slot 11 has 4 layers of straight segments 211.

Referring to fig. 6, fig. 6 is a schematic diagram of a slot layer structure of a stator slot in the stator core shown in fig. 2, where N is 6, each stator slot 11 is provided with 6 layers of straight line segments 211, that is, each stator slot 11 contains 4 layers of flat line conductors, where the 1 st layer is L1, the 2 nd layer is L2, the 3 rd layer is L3, the 4 th layer is L4, the 5 th layer is L5, and the 6 th layer is L6. Wherein the 1 st slot layer is the tank bottom layer of stator slot 11, and the 6 th slot layer is the notch layer, or the 1 st slot layer is the notch layer of stator slot 11, and the 6 th slot layer is the tank bottom layer.

In one embodiment, the hairpin coils 21 in the same stator slot 11 are in the same phase, so that no interphase insulating paper is needed between different layers of straight line segments 211 in the same stator slot 11, and the insulation cost of the flat wire motor can be reduced.

Wherein, when N = (2n + 1) × 2, the total number of slot layers occupied by each parallel branch in each stator slot 11 is 2N, or 2N, 2N-1, 2N-2; when N =2N × 2, the total number of slot layer combinations occupied by each parallel branch at each stator slot 11 is 2N, 2N-1, or 2N, 2N-1, 2N-2; when N =2n +1, the total number of the slot layers occupied by each parallel branch in each stator slot 11 is N, N-1, or N, N-1, N-2; wherein N is a positive integer and is greater than or equal to 4, and the total number of slot layers of each parallel branch in each stator slot 11 is also a positive integer.

For example, if the number N of the slot layers of the stator slot 11 is 4, the total number of slot layers occupied by each parallel branch in each stator slot 11 may be 2 or 1; when the number N of the slot layers of the stator slot 11 is 6, the total number combination of the slot layers occupied by each parallel branch in each stator slot 11 may be 2, or 2, 1; when the number N of the slot layers of the stator slot 11 is 7, the total number of slot layers occupied by each stator slot 11 in each parallel branch may be 3, 2 or 3, 2, 1.

The linear type of the hairpin coil 21 is reduced by limiting the number N of the slot layers in the stator slot 11 and the total number of the slot layers occupied by each parallel branch in each stator slot, so that the manufacturing die of the flat wire motor is reduced, the manufacturing cost is reduced, and the processing and manufacturing efficiency can be effectively improved.

When the total number of the slot layers occupied by each parallel branch in the stator slot 11 is 1, the position of one slot layer is the first layer or the Nth layer of the stator slot 11; when the total number of the slot layers occupied by each parallel branch in the stator slot 11 is 2, the 2 slot layers are adjacently arranged in the stator slot 11, or the 2 slot layers are respectively the first layer and the Nth layer in the stator slot 11; when the total number of the slot layers occupied by each parallel branch in the stator slot 11 is 3, two of the 3 slot layers are adjacently arranged, the position of the rest slot layer is the first layer or the Nth layer of the stator slot 11, and four slot layers are separated from the other two slot layers; when the total number of the slot layers occupied by each parallel branch in the stator slot 11 is 4, the 4 slot layers are divided into two groups, each group is separated by four slot layers, and each group comprises two adjacent slot layers. By this limiting measure, the line type of the hairpin coil 21 can be further reduced, that is, the number of manufacturing dies can be further reduced, the cost can be reduced, and the manufacturing efficiency can be improved.

In one embodiment, the pitch combination of the hairpin coils 21 in each parallel branch is 8, 9, 11. In another embodiment, the hairpin coils 21 of each parallel branch at the same slot level have a pitch of 9. In yet another embodiment, the hairpin coils 21 pitch of each parallel leg in the first or nth slot layer is 8 or 8, 11. The pitch of the hairpin coil 21 is the number of stator slots spanned by two straight line segments 211 in the hairpin coil 21.

The welding pitches between the hairpin coils 21 in each parallel branch may be all 9, that is, the number of stator slots spanned by two adjacent straight segments 211 in two adjacent hairpin coils 21 in the same parallel branch is all 9.

In some embodiments, the inlet end of each parallel branch is on the Nth slot layer of the stator slot 11, and the outlet end is on the N-1 th slot layer of the stator slot 11; or the inlet wire end and the outlet wire end of each parallel branch are arranged on the first slot layer and the Nth slot layer of the stator slot 11, so that the inlet wire end and the outlet wire end of each parallel branch can be led out conveniently. The positions of the lead-out wires of the parallel branches are concentrated, so that the axial and radial spaces of the winding can be reduced, and the manufacturing difficulty of the flat wire motor is reduced.

The embodiment of the application also provides a power assembly, and the power assembly comprises a speed reducer and the flat wire motor. Wherein, the flat wire motor is in transmission connection with the reducer. Specifically, the drive shaft of the flat wire motor and the input shaft of the speed reducer can be in transmission connection through transmission parts such as a coupler, so that the driving force is output to the speed reducer from the flat wire motor.

The vehicle that this application embodiment provided, including foretell powertrain, foretell powertrain sets up in the vehicle to for the vehicle provides operation power. Specifically, in the present embodiment, the vehicle may specifically be a new energy vehicle that is driven by electric energy. The new energy vehicle may be a hybrid electric vehicle, a pure electric vehicle, a fuel cell electric vehicle, or the like, or may be a vehicle using a super capacitor, a flywheel battery, a flywheel energy storage, or a high-efficiency energy storage device such as a flywheel energy storage device as an electric energy source.

The connection manner of the parallel branches in the present application will be described in detail with reference to specific embodiments.

In the first embodiment, a 6-pole 54-slot flat-wire motor is taken as an example, where the number of the stator slots 11 in the stator core 10 is 54, the number of poles of the rotor is 6, the number of slots per pole and per phase is 3, and the number of slot layers N in each stator slot 11 is 4. The stator winding is divided into a U phase, a V phase and a W phase, and the number of parallel branches arranged on each phase of winding is 3.

Referring to fig. 7, fig. 7 is a schematic diagram of a first winding of a U-phase winding of a 6-pole 54-slot flat-wire motor provided in the present application when the number of slot layers is 4; fig. 8 is a schematic diagram of a second winding of the U-phase winding in the case of a 6-pole 54-slot flat-wire motor provided by the present application and having 4 slot layers. The solid line represents the connection mode of the plug terminal, the dotted line represents the connection mode of the welding terminal, U1, U2 and U3 can be used as voltage leading-out wires or neutral point leading-out wires, and X1, X2 and X3 can be used as voltage leading-out wires or neutral point leading-out wires.

The first parallel branch, the second parallel branch, and the third parallel branch in the U-phase winding in this embodiment are described in detail below with reference to fig. 7 and fig. 8.

Where i (j) denotes a jth groove layer in the ith groove, for example, 1 (1) denotes a 1 st groove layer of the 1 st groove, and 10 (2) denotes a 2 nd groove layer of the 10 th groove.

The winding modes of the first parallel branch, the second parallel branch and the third parallel branch of the U-phase winding are 2.

As shown in fig. 7, in the first winding method, the number of the slots through which the first parallel branches of the U-phase winding are connected in series is: 1 (1) → 10 (2) → 21 (1) → 30 (2) → 38 (1) → 47 (2) → 2 (3) → 11 (4) → 19 (3) → 28 (4) → 39 (3) → 48 (4) → 2 (4) → 47 (3) → 39 (4) → 30 (3) → 19 (4) → 10 (3) → 1 (2) → 46 (1) → 38 (2) → 29 (1) → 21 (2) → 12 (1).

The serial connection of the second parallel branch of the U-phase winding is carried out through the following slots: 2 (1) → 11 (2) → 19 (1) → 28 (2) → 39 (1) → 48 (2) → 3 (3) → 12 (4) → 20 (3) → 29 (4) → 37 (3) → 46 (4) → 3 (4) → 48 (3) → 37 (4) → 28 (3) → 20 (4) → 11 (3) → 2 (2) → 47 (1) → 39 (2) → 30 (1) → 19 (2) → 10 (1).

The number of the serial connection passing through the third parallel branch of the U-phase winding is as follows: 3 (1) → 12 (2) → 20 (1) → 29 (2) → 37 (1) → 46 (2) → 1 (3) → 10 (4) → 21 (3) → 30 (4) → 38 (3) → 47 (4) → 1 (4) → 46 (3) → 38 (4) → 29 (3) → 21 (4) → 12 (3) → 3 (2) → 48 (1) → 37 (2) → 28 (1) → 20 (2) → 11 (1).

As shown in fig. 8, in the second winding method, the number of the slots through which the first parallel branches of the U-phase winding are connected in series is: 1 (1) → 10 (2) → 19 (3) → 28 (4) → 39 (3) → 48 (4) → 2 (3) → 11 (4) → 2 (4) → 47 (3) → 39 (4) → 30 (3) → 19 (4) → 10 (3) → 1 (2) → 46 (1) → 38 (2) → 29 (1) → 21 (2) → 12 (1) → 21 (1) → 30 (2) → 38 (1) → 47 (2).

The number of the serial connection passing through the second parallel branch of the U-phase winding is as follows: 2 (1) → 11 (2) → 20 (3) → 29 (4) → 37 (3) → 46 (4) → 3 (3) → 12 (4) → 3 (4) → 48 (3) → 37 (4) → 28 (3) → 20 (4) → 11 (3) → 2 (2) → 47 (1) → 39 (2) → 30 (1) → 19 (2) → 10 (1) → 19 (1) → 28 (2) → 39 (1) → 48 (2).

The number of the grooves which are connected in series and pass through the third parallel branch of the U-phase winding is as follows: 3 (1) → 12 (2) → 21 (3) → 30 (4) → 38 (3) → 47 (4) → 1 (3) → 10 (4) → 1 (4) → 46 (3) → 38 (4) → 29 (3) → 21 (4) → 12 (3) → 3 (2) → 48 (1) → 37 (2) → 28 (1) → 20 (2) → 11 (1) → 20 (1) → 29 (2) → 37 (1) → 46 (2).

The U-phase winding, the V-phase winding and the W-phase winding are symmetrically and uniformly distributed on the circumference of the stator core 10, and the winding manner of the V-phase winding and the W-phase winding is not described herein again.

In the second embodiment, a 6-pole 54-slot flat-wire motor is also taken as an example, where the number of the stator slots 11 in the stator core 10 is 54, the number of poles of the rotor is 6, the number of slots per pole and per phase is 3, and the number of slot layers N in each stator slot 11 is 5. The stator winding is divided into a U phase, a V phase and a W phase, and the number of parallel branches arranged on each phase of winding is 3.

Referring to fig. 9, fig. 9 is a winding diagram of a U-phase winding of a 6-pole 54-slot flat-wire motor provided in the present application, where the number of slot layers is 5.

As shown in fig. 9, the number of the slots through which the first parallel branch of the U-phase winding is connected in series is: 1 (1) → 10 (2) → 21 (1) → 30 (2) → 38 (1) → 47 (2) → 2 (3) → 11 (4) → 19 (3) → 28 (4) → 39 (3) → 48 (4) → 3 (5) → 48 (5) → 37 (5) → 28 (5) → 20 (5) → 11 (5) → 2 (4) → 47 (3) → 39 (4) → 30 (3) → 19 (4) → 10 (3) → 1 (2) → 46 (1) → 38 (2) → 29 (1) → 21 (2) → 12 (1).

The serial connection of the second parallel branch of the U-phase winding is carried out through the following slots: 2 (1) → 11 (2) → 19 (1) → 28 (2) → 39 (1) → 48 (2) → 3 (3) → 12 (4) → 20 (3) → 29 (4) → 37 (3) → 46 (4) → 1 (5) → 46 (5) → 38 (5) → 29 (5) → 21 (5) → 12 (5) → 3 (4) → 48 (3) → 37 (4) → 28 (3) → 20 (4) → 11 (3) → 2 (2) → 47 (1) → 39 (2) → 30 (1) → 19 (2) → 10 (1).

The number of the grooves which are connected in series and pass through the third parallel branch of the U-phase winding is as follows: 3 (1) → 12 (2) → 20 (1) → 29 (2) → 37 (1) → 46 (2) → 1 (3) → 10 (4) → 21 (3) → 30 (4) → 38 (3) → 47 (4) → 2 (5) → 47 (5) → 39 (5) → 30 (5) → 19 (5) → 10 (5) → 1 (4) → 46 (3) → 38 (4) → 29 (3) → 21 (4) → 12 (3) → 3 (2) → 48 (1) → 37 (2) → 28 (1) → 20 (2) → 11 (1).

In the third embodiment, still taking a 6-pole 54-slot flat-wire motor as an example, the number of the stator slots 11 in the stator core 10 is 54, the number of poles of the rotor is 6, the number of slots per phase per pole is 3, and the number of slot layers N in each stator slot 11 is 6. The stator winding is divided into a U phase, a V phase and a W phase, and the number of parallel branches arranged on each phase of winding is 3.

The winding modes of the first parallel branch, the second parallel branch and the third parallel branch of the U-phase winding are 2. Referring to fig. 10 and 11, fig. 10 is a schematic diagram of a first winding of a U-phase winding when the number of slot layers is 6 for a 6-pole 54-slot flat-wire motor provided by the present application, and fig. 11 is a schematic diagram of a second winding of the U-phase winding when the number of slot layers is 6 for the 6-pole 54-slot flat-wire motor provided by the present application.

As shown in fig. 10, in the first winding method, the number of slots through which the first parallel branches of the U-phase winding are connected in series is: 1 (1) → 10 (2) → 21 (1) → 30 (2) → 38 (1) → 47 (2) → 2 (3) → 11 (4) → 19 (3) → 28 (4) → 39 (3) → 48 (4) → 3 (5) → 12 (6) → 20 (5) → 29 (6) → 37 (5) → 46 (6) → 3 (6) → 48 (5) → 37 (6) → 28 (5) → 20 (6) → 11 (5) → 2 (4) → 47 (3) → 39 (4) → 30 (3) → 19 (4) → 10 (3) → 28) → 1 (2) → 46 (1) → 38 (2) → 29 (1) → 21 (2) → 12 (1).

The number of the serial connection passing through the second parallel branch of the U-phase winding is as follows: 2 (1) → 11 (2) → 19 (1) → 28 (2) → 39 (1) → 48 (2) → 3 (3) → 12 (4) → 20 (3) → 29 (4) → 37 (3) → 46 (4) → 1 (5) → 10 (6) → 21 (5) → 30 (6) → 38 (5) → 47 (6) → 1 (6) → 46 (5) → 38 (6) → 29 (5) → 21 (6) → 12 (5) → 3 (4) → 48 (3) → 37 (4) → 28 (3) → 20 (4) → 11 (3) → 2 (2) → 47 (1) → 39 (2) → 30 (1) → 19 (2) → 10 (1).

The number of the grooves which are connected in series and pass through the third parallel branch of the U-phase winding is as follows: 3 (1) → 12 (2) → 20 (1) → 29 (2) → 37 (1) → 46 (2) → 1 (3) → 10 (4) → 21 (3) → 30 (4) → 38 (3) → 47 (4) → 2 (5) → 11 (6) → 19 (5) → 28 (6) → 39 (5) → 48 (6) → 2 (6) → 47 (5) → 39 (6) → 30 (5) → 19 (6) → 10 (5) → 1 (4) → 46 (3) → 38 (4) → 29 (3) → 21 (4) → 12 (3) → 3 (2) → 48 (1) → 37 (2) → 28 (1) → 20 (2) → 11 (1).

As shown in fig. 11, in the second winding method, the number of the slots through which the first parallel branches of the U-phase winding are connected in series is: 1 (1) → 10 (2) → 19 (3) → 28 (4) → 39 (3) → 48 (4) → 2 (3) → 11 (4) → 20 (5) → 29 (6) → 37 (5) → 46 (6) → 3 (5) → 12 (6) → 3 (6) → 48 (5) → 37 (6) → 28 (5) → 20 (6) → 11 (5) → 2 (4) → 47 (3) → 39 (4) → 30 (3) → 19 (4) → 10 (3) → 1 (2) → 46 (1) → 38 (2) → 29 (1) → 21 (2) → 12 (1) → 21 (1) → 30 (2) → 38 (1) → 47 (2).

The number of the serial connection passing through the second parallel branch of the U-phase winding is as follows: 2 (1) → 11 (2) → 20 (3) → 29 (4) → 37 (3) → 46 (4) → 3 (3) → 12 (4) → 21 (5) → 30 (6) → 38 (5) → 47 (6) → 1 (5) → 10 (6) → 1 (6) → 46 (5) → 38 (6) → 29 (5) → 21 (6) → 12 (5) → 3 (4) → 48 (3) → 37 (4) → 28 (3) → 20 (4) → 11 (3) → 2) → 47 (1) → 39 (2) → 30 (1) → 19 (2) → 10 (1) → 19 (1) → 28 (2) → 39 (1) → 28 (2) → 39 (1) → 48 (2) → 39 (2) → 48 (2).

The number of the grooves which are connected in series and pass through the third parallel branch of the U-phase winding is as follows: 3 (1) → 12 (2) → 21 (3) → 30 (4) → 38 (3) → 47 (4) → 1 (3) → 10 (4) → 19 (5) → 28 (6) → 39 (5) → 48 (6) → 2 (5) → 11 (6) → 2 (6) → 47 (5) → 39 (6) → 30 (5) → 19 (6) → 10 (5) → 1 (4) → 46 (3) → 38 (4) → 29 (3) → 21 (4) → 12 (3) → 3 (2) → 48 (1) → 37 (2) → 28 (1) → 20 (2) → 11 (1) → 29 (2) → 37 (1) → 37 (2) → 37 (1) → 46).

In the fourth embodiment, still taking a 6-pole 54-slot flat-wire motor as an example, the number of the stator slots 11 in the stator core 10 is 54, the number of poles of the rotor is 6, the number of slots per phase per pole is 3, and the number of slot layers N in each stator slot 11 is 7. The stator winding is divided into a U phase, a V phase and a W phase, and the number of parallel branches arranged on each phase of winding is 3.

Referring to fig. 12, fig. 12 is a winding diagram of a U-phase winding of a 6-pole 54-slot flat-wire motor provided in the present application when the number of slot layers is 7.

As shown in fig. 12, the number of the slots through which the first parallel branch of the U-phase winding is connected in series is: 1 (1) → 10 (2) → 21 (1) → 30 (2) → 38 (1) → 47 (2) → 2 (3) → 11 (4) → 19 (3) → 28 (4) → 39 (3) → 48 (4) → 3 (5) → 12 (6) → 20 (5) → 29 (6) → 37 (5) → 46 (6) → 1 (7) → 46 (7) → 38 (7) → 29 (7) → 21 (7) → 12 (7) → 3 (6) → 48 (5) → 37 (6) → 28 (5) → 20 (6) → 11 (5) → 2 (4) → 47 (3) → 39 (4) → 30 (3) → 19 (4) → 10) → 1 (2) → 1) → 38 (1) → 2) → 1 (4) → 1 (38).

The number of the serial connection passing through the second parallel branch of the U-phase winding is as follows: 2 (1) → 11 (2) → 19 (1) → 28 (2) → 39 (1) → 48 (2) → 3 (3) → 12 (4) → 20 (3) → 29 (4) → 37 (3) → 46 (4) → 1 (5) → 10 (6) → 21 (5) → 30 (6) → 38 (5) → 47 (6) → 2 (7) → 47 (7) → 39 (7) → 39 (7) → 30 (7) → 19 (7) → 10 (7) → 1 (6) → 46 (5) → 38 (6) → 29) → 21 (6) → 12 (5) → 3 (4) → 48 (3) → 37 (4) → 30 (7) → 20) → 11) → 3) → 19 (4) → 1 (4) → 2) → 39 (6) → 1 (5) → 2).

The number of the grooves which are connected in series and pass through the third parallel branch of the U-phase winding is as follows: 3 (1) → 12 (2) → 20 (1) → 29 (2) → 37 (1) → 46 (2) → 1 (3) → 10 (4) → 21 (3) → 30 (4) → 38 (3) → 47 (4) → 2 (5) → 11 (6) → 19 (5) → 28 (6) → 39 (5) → 48 (6) → 3 (7) → 48 (7) → 37 (7) → 28 (7) → 20 (7) → 11 (7) → 2 (6) → 47 (5) → 39 (6) → 30 (5) → 19 (6) → 10 (5) → 1 (4) → 46 (3) → 38 (4) → 29 (3) → 21 (4) → 12) → 2) → 1 (3) → 11 (11) → 11 (4) → 1 (6) → 11).

In the fifth embodiment, a 6-pole 54-slot flat-wire motor is also taken as an example, where the number of the stator slots 11 in the stator core 10 is 54, the number of poles of the rotor is 6, the number of slots per pole and per phase is 3, and the number of slot layers N in each stator slot 11 is 8. The stator winding is divided into a U phase, a V phase and a W phase, and the number of parallel branches arranged on each phase of winding is 3.

Referring to fig. 13, fig. 13 is a winding diagram of a U-phase winding of a 6-pole 54-slot flat-wire motor provided in the present application, where the number of slot layers is 8.

As shown in fig. 13, the number of the slots through which the first parallel branch of the U-phase winding is connected in series is: 1 (1) → 10 (2) → 21 (1) → 30 (2) → 38 (1) → 47 (2) → 2 (3) → 11 (4) → 19 (3) → 28 (4) → 39 (3) → 48 (4) → 3 (5) → 12 (6) → 20 (5) → 29 (6) → 37 (5) → 46 (6) → 1 (7) → 10 (8) → 21 (7) → 30 (8) → 38 (7) → 47 (8) → 38 (8) → 1) 1 (8) → 46 (7) → 38 (8) → 29 (7) → 21 (8) → 12 (7) → 3 (6) → 48 (5) → 37 (6) → 28 (5) → 20 (6) → 11 (5) → 2 (4) → 47 (3) → 39 (4) → 30 (3) → 19 (4) → 10 (3) → 1 (2) → 46 (1) → 38 (2) → 29 (1) → 21 (2) → 12 (1).

The serial connection of the second parallel branch of the U-phase winding is carried out through the following slots: 2 (1) → 11 (2) → 19 (1) → 28 (2) → 39 (1) → 48 (2) → 3 (3) → 12 (4) → 20 (3) → 29 (4) → 37 (3) → 46 (4) → 1 (5) → 10 (6) → 21 (5) → 30 (6) → 38 (5) → 47 (6) → 2 (7) → 11 (8) → 19 (7) → 28 (8) → 39 (7) → 48 (8) → 39) 2 (8) → 47 (7) → 39 (8) → 30 (7) → 19 (8) → 10 (7) → 1 (6) → 46 (5) → 38 (6) → 29 (5) → 21 (6) → 12 (5) → 3 (4) → 48 (3) → 37 (4) → 28 (3) → 20 (4) → 11 (3) → 2 (2) → 47 (1) → 39 (2) → 30 (1) → 19 (2) → 10 (1).

The number of the grooves which are connected in series and pass through the third parallel branch of the U-phase winding is as follows: 3 (1) → 12 (2) → 20 (1) → 29 (2) → 37 (1) → 46 (2) → 1 (3) → 10 (4) → 21 (3) → 30 (4) → 38 (3) → 47 (4) → 2 (5) → 11 (6) → 19 (5) → 28 (6) → 39 (5) → 48 (6) → 3 (7) → 12 (8) → 20 (7) → 29 (8) → 37 (7) → 46 (8) → and 3 (8) → 48 (7) → 37 (8) → 28 (7) → 20 (8) → 11 (7) → 2 (6) → 47 (5) → 39 (6) → 30 (5) → 19 (6) → 10 (5) → 1 (4) → 46 (3) → 38 (4) → 29 (3) → 21 (4) → 12 (3) → 3 (2) → 48 (1) → 37 (2) → 28 (1) → 20 (2) → 11 (1).

In the sixth embodiment, a 6-pole 54-slot flat-wire motor is also taken as an example, where the number of stator slots 11 in the stator core 10 is 54, the number of poles of the rotor is 6, the number of slots per phase per pole is 3, and the number of slot layers N in each stator slot 11 is 9. The stator winding is divided into a U phase, a V phase and a W phase, and the number of parallel branches arranged on each phase of winding is 3.

Referring to fig. 14, fig. 14 is a winding diagram of a U-phase winding of a 6-pole 54-slot flat-wire motor provided in the present application when the number of slot layers is 9.

As shown in fig. 14, the number of the slots through which the first parallel branch of the U-phase winding is connected in series is: 1 (1) → 10 (2) → 21 (1) → 30 (2) → 38 (1) → 47 (2) → 2 (3) → 11 (4) → 19 (3) → 28 (4) → 39 (3) → 48 (4) → 3 (5) → 12 (6) → 20 (5) → 29 (6) → 37 (5) → 46 (6) → 1 (7) → 10 (8) → 21 (7) → 30 (8) → 38 (7) → 47 (8) → 2 (9) → 47 (9) → 39 (9) → 8) → 21 (7) 30 (9) → 19 (9) → 10 (9) → 1 (8) → 46 (7) → 38 (8) → 29 (7) → 21 (8) → 12 (7) → 3 (6) → 48 (5) → 37 (6) → 28 (5) → 20 (6) → 11 (5) → 2 (4) → 47 (3) → 39 (4) → 30 (3) → 19 (4) → 10 (3) → 1 (2) → 46 (1) → 38 (2) → 29 (1) → 21 (2) → 12 (1).

The number of the serial connection passing through the second parallel branch of the U-phase winding is as follows: 2 (1) → 11 (2) → 19 (1) → 28 (2) → 39 (1) → 48 (2) → 3 (3) → 12 (4) → 20 (3) → 29 (4) → 37 (3) → 46 (4) → 1 (5) → 10 (6) → 21 (5) → 30 (6) → 38 (5) → 47 (6) → 2 (7) → 11 (8) → 19 (7) → 26 (8) → 39 (7) → 48 (8) → 3 (9) → 46 (9) → 37 (9) → 8 → and 28 (9) → 20 (9) → 11 (9) → 2 (8) → 47 (7) → 39 (8) → 30 (7) → 19 (8) → 10 (7) → 1 (6) → 46 (5) → 38 (6) → 29 (5) → 21 (6) → 12 (5) → 3 (4) → 48 (3) → 37 (4) → 28 (3) → 20 (4) → 11 (3) → 2 (2) → 47 (1) → 39 (2) → 30 (1) → 19 (2) → 10 (1).

The number of the grooves which are connected in series and pass through the third parallel branch of the U-phase winding is as follows: 3 (1) → 12 (2) → 20 (1) → 29 (2) → 37 (1) → 46 (2) → 1 (3) → 10 (4) → 21 (3) → 30 (4) → 38 (3) → 47 (4) → 2 (5) → 11 (6) → 19 (5) → 28 (6) → 39 (5) → 48 (6) → 3 (7) → 12 (8) → 20 (7) → 29 (8) → 37 (7) → 46 (8) → 1 (9) → 46 (9) → 38 (9) → 8) → 2 (5) → 1 (9) → 38 (4) → 2 29 (9) → 21 (9) → 12 (9) → 3 (8) → 48 (7) → 37 (8) → 28 (7) → 20 (8) → 11 (7) → 2 (6) → 47 (5) → 39 (6) → 30 (5) → 19 (6) → 10 (5) → 1 (4) → 46 (3) → 38 (4) → 29 (3) → 21 (4) → 12 (3) → 3 (2) → 48 (1) → 37 (2) → 28 (1) → 20 (2) → 11 (1).

In the sixth embodiment, a 6-pole 54-slot flat-wire motor is also taken as an example, where the number of the stator slots 11 in the stator core 10 is 54, the number of poles of the rotor is 6, the number of slots per pole and per phase is 3, and the number of slot layers N in each stator slot 11 is 10. The stator winding is divided into a U phase, a V phase and a W phase, and the number of parallel branches arranged on each phase of winding is 3.

Referring to fig. 15, fig. 15 is a winding schematic diagram of a U-phase winding of a 6-pole 54-slot flat-wire motor provided in the present application when the number of slot layers is 10.

As shown in fig. 15, the number of the slots through which the first parallel branch of the U-phase winding is connected in series is: 1 (1) → 10 (2) → 21 (1) → 30 (2) → 38 (1) → 47 (2) → 2 (3) → 11 (4) → 19 (3) → 28 (4) → 39 (3) → 48 (4) → 3 (5) → 12 (6) → 20 (5) → 29 (6) → 37 (5) → 46 (6) → 1 (7) → 10 (8) → 21 (7) → 30 (8) → 38 (7) → 47 (8) → 2 (9) → 11 (10) → 19 (9) → 28 (10) → 39 (9) → 48 (10) → 38 (7) → 47 (8) → 2 (9) → 11 (10) → 19 (9) → 28 (10) → 39 (9) → 48 (10) → 48) 2 (10) → 47 (9) → 39 (10) → 30 (9) → 19 (10) → 10 (9) → 1 (8) → 46 (7) → 38 (8) → 29 (7) → 21 (8) → 12 (7) → 3 (6) → 48 (5) → 37 (6) → 28 (5) → 20 (6) → 11 (5) → 2 (4) → 47 (3) → 39 (4) → 30 (3) → 19 (4) → 10 (3) → 1 (2) → 46 (1) → 38 (2) → 28 (1) → 21 (2) → 12 (1).

The number of the serial connection passing through the second parallel branch of the U-phase winding is as follows: 2 (1) → 11 (2) → 19 (1) → 28 (2) → 39 (1) → 48 (2) → 3 (3) → 12 (4) → 20 (3) → 29 (4) → 37 (3) → 46 (4) → 1 (5) → 10 (6) → 21 (5) → 30 (6) → 38 (5) → 47 (6) → 2 (7) → 11 (8) → 19 (7) → 26 (8) → 39 (7) → 48 (8) → 3 (9) → 12 (10) → 20 (9) → 29 (10) → 37 (9) → 46 (10) → 46 (8) 3 (10) → 48 (9) → 37 (10) → 28 (9) → 20 (10) → 11 (9) → 2 (8) → 47 (7) → 39 (8) → 30 (7) → 19 (8) → 10 (7) → 1 (6) → 46 (5) → 38 (6) → 29 (5) → 21 (6) → 12 (5) → 3 (4) → 48 (3) → 37 (4) → 28 (3) → 20 (4) → 11 (3) → 2 (2) → 47 (1) → 39 (2) → 30 (1) → 19 (2) → 10 (1).

The number of the serial connection passing through the third parallel branch of the U-phase winding is as follows: 3 (1) → 12 (2) → 20 (1) → 29 (2) → 37 (1) → 46 (2) → 1 (3) → 10 (4) → 21 (3) → 30 (4) → 38 (3) → 47 (4) → 2 (5) → 11 (6) → 19 (5) → 28 (6) → 39 (5) → 48 (6) → 3 (7) → 12 (8) → 20 (7) → 29 (8) → 37 (7) → 46 (8) → 1 (9) → 10 (10) → 21 (9) → 30 (10) → 36 (9) → 47 (10) → 37 (7) → 46 (8) → 1 (9) → 10 (9) → 21 (9) → 30 (10) → 36 (9) → 47 (10) → 47) 1 (10) → 46 (9) → 38 (10) → 29 (9) → 21 (10) → 12 (9) → 3 (8) → 48 (7) → 37 (8) → 28 (7) → 20 (8) → 11 (7) → 2 (6) → 47 (5) → 39 (6) → 30 (5) → 19 (6) → 10 (5) → 1 (4) → 46 (3) → 38 (4) → 29 (3) → 21 (4) → 12 (3) → 3 (2) → 48 (1) → 37 (2) → 28 (1) → 20 (2) → 11 (1).

Being different from the situation of the prior art, the application discloses a stator, a flat wire motor, a power assembly and a vehicle. The magnetic field distribution of the parallel branches in each phase of winding is the same and the potential is balanced by the rotation symmetry of the parallel branches in the circumferential direction, so that the circulation generated among the parallel branches is avoided, the additional alternating current copper consumption under high frequency can be greatly reduced, the efficiency of the flat wire motor in high-speed operation is improved, the local over-temperature of the winding is avoided, and the service life of the flat wire motor is prolonged; and the hairpin coil of each parallel branch traverses N slot layers in different stator slots, so that the potential phase difference caused by the positions of a plurality of parallel branches in each phase winding in the stator slots can be eliminated, the linear type of the hairpin coil is reduced by limiting the number N of slot layers in the stator slots and the total number of slot layers occupied by each parallel branch in each stator slot, the manufacturing die of the flat wire motor is reduced, the manufacturing cost is reduced, and the processing and manufacturing efficiency can be effectively improved.

The above description is only an example of the present application, and is not intended to limit the scope of the present application, and all equivalent structures or equivalent processes performed by the present application and the contents of the attached drawings, which are directly or indirectly applied to other related technical fields, are also included in the scope of the present application.

Claims

1. A stator of a flat wire motor, comprising:

the inner wall of the stator core is circumferentially provided with a plurality of uniformly distributed stator slots;

the stator winding comprises three-phase windings, each phase winding comprises a plurality of parallel branches, the parallel branches are rotationally symmetrical in the circumferential direction, each parallel branch comprises a plurality of hairpin coils which are connected through connecting wires and have different pitches, N layers of hairpin coils are arranged in any stator slot, the hairpin coils of each parallel branch traverse N slot layers in different stator slots, and the three-phase windings are sequentially arranged in a periodic manner along the circumferential direction of the stator core;

when N = (2n + 1) × 2, the total number of slot layers occupied by each parallel branch in each stator slot is 2N, or 2N, 2N-1, 2N-2;

when N =2N × 2, the total number of slot layers occupied by each parallel branch in each stator slot is 2N, 2N-1, or 2N, 2N-1, 2N-2;

when N =2n +1, the total number of the groove layers occupied by each parallel branch in each stator groove is N, N-1, or N, N-1, N-2; wherein N is a positive integer and is greater than or equal to 4, and the total number of slot layers of each parallel branch in each stator slot is also a positive integer.

2. The stator according to claim 1,

when the total number of the slot layers occupied by each parallel branch in the stator slot is 1, the position of one slot layer is the first layer or the Nth layer of the stator slot;

when the total number of the slot layers occupied by each parallel branch in the stator slot is 3, two of the 3 slot layers are adjacently arranged, the position of the rest slot layer is the first layer or the Nth layer of the stator slot, and four slot layers are separated from the other two slot layers;

3. A stator according to claim 2, wherein each phase winding comprises three parallel legs.

4. A stator according to claim 3, wherein the number of stator slots is 54 or 72.

5. A stator according to claim 3 or 4, wherein the combination of the pitches of the hairpin coils in each of the parallel branches is 8, 9, 11.

6. A stator according to claim 3 or 4, wherein the hairpin pitch of each parallel branch in the same slot layer is 9.

7. A stator according to claim 3 or 4, characterized in that the hairpin pitch of each parallel branch in the first or Nth slot layer is 8 or 8, 11.

8. The stator according to claim 3 or 4, wherein the inlet end of each parallel branch is on the Nth layer of the slot layer, and the outlet end is on the N-1 th layer of the slot layer; or

9. A stator according to claim 3 or 4, characterized in that the welding pitch between the hairpin coils in each of the parallel branches is 9.

10. A flat wire motor comprising a stator according to any one of claims 1 to 9 and a rotor provided in a space defined by an inner wall of the stator core.

11. A power assembly comprising a speed reducer and the flat wire motor of claim 10, said flat wire motor being drivingly connected to said speed reducer.

12. A vehicle comprising a powertrain as recited in claim 11.