CN216530789U

CN216530789U - Three-phase stator winding, motor stator assembly and motor

Info

Publication number: CN216530789U
Application number: CN202123217406.XU
Authority: CN
Inventors: 张冰冰; 何丽娜; 高涛
Original assignee: Honeycomb Transmission Technology Hebei Co Ltd
Current assignee: Honeycomb Transmission Technology Hebei Co Ltd
Priority date: 2021-12-20
Filing date: 2021-12-20
Publication date: 2022-05-13
Anticipated expiration: 2031-12-20

Abstract

The utility model provides a three-phase stator winding, a motor stator assembly and a motor, belonging to the technical field of motors, wherein each phase winding comprises a plurality of parallel branches, and each parallel branch comprises a plurality of first hairpin conductors, a second hairpin conductor and a third hairpin conductor; the second card sending wire is connected between two first card sending wires positioned on the same layer, and the third card sending wire is connected between the other two first card sending wires positioned on the same layer; the two hairpin welding sections of the first hairpin conductor extend in opposite directions, the two hairpin welding sections of the second hairpin conductor extend in the same direction, and the two hairpin welding sections of the third hairpin conductor extend in the same direction and are opposite to the extending direction of the two hairpin welding sections of the second hairpin conductor. The utility model can reduce the star point line and the connection length of the hairpin welding section of the hairpin conductor, simplify the end welding, improve the production efficiency, reduce the end height of the winding, reduce the copper wire consumption, reduce the resistivity and improve the motor efficiency.

Description

Three-phase stator winding, motor stator assembly and motor

Technical Field

The utility model belongs to the technical field of motors, and particularly relates to a three-phase stator winding, a motor stator assembly and a motor.

Background

The hairpin motor is a motor which adopts a flat copper hairpin wire to replace a traditional thin round wire in a stator winding of a driving motor, and the stator winding of the hairpin motor is shaped like a hairpin. The stator winding comprises a plurality of hairpin conductors, and the hairpin conductors penetrate into stator slots of a stator core according to a certain arrangement mode to form the required winding of the single-phase motor or the multi-phase motor.

In the prior art, the arrangement mode of a plurality of hairpin conductors is complex, and a large number of bus bars and bus bars are needed to connect branches and neutral points of windings of each phase, so that the manufacturing process of the windings is complex, the production cost is high, and the processing efficiency is low.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a three-phase stator winding, a motor stator assembly and a motor, and aims to solve the technical problems of complex manufacturing process, high production cost and low processing efficiency of the winding of a hairpin motor in the prior art.

In a first aspect, an embodiment of the present invention provides a three-phase stator winding, including an a-phase winding, a B-phase winding, and a C-phase winding, where each phase winding includes a plurality of parallel branches, each parallel branch is superimposed with N layers of hairpin conductors, and N is equal to or greater than 4 and is an even number; the N layers of the hairpin conductors in each parallel branch comprise a plurality of first hairpin conductors, a second hairpin conductor and a third hairpin conductor; the second hairpin conductor is connected between the two first hairpin conductors positioned on the same layer, and the third hairpin conductor is connected between the other two first hairpin conductors positioned on the same layer;

each hairpin conductor comprises two in-slot conductor segments penetrating into different stator slots, a hairpin inserting segment which is positioned outside the stator slots and connected to one end of each in-slot conductor segment, and two hairpin welding segments which are positioned outside the stator slots and respectively connected to the other ends of the two in-slot conductor segments; the hairpin welding section and the in-groove wire section are arranged in an included angle;

the two hairpin welding sections of the first hairpin conductor extend in opposite directions, the two hairpin welding sections of the second hairpin conductor extend in the same direction, the two hairpin welding sections of the third hairpin conductor extend in the same direction, and the extending directions of the two hairpin welding sections of the second hairpin conductor are opposite to the extending direction of the hairpin welding sections of the third hairpin conductor.

With reference to the first aspect, in one possible implementation manner, the two hairpin welding sections of the first hairpin conductor are symmetrically arranged; the two hairpin welding sections of the second hairpin conductor are arranged in parallel, and the two hairpin welding sections of the third hairpin conductor are arranged in parallel.

With reference to the first aspect, in a possible implementation manner, each parallel branch includes a first coil, a second coil, and a third coil that are sequentially connected;

the first coil comprises at least one first hairpin conductor and at least one second hairpin conductor which are sequentially connected;

the second coil comprises at least fifteen first card sending conducting wires and at least fifteen third card sending conducting wires which are connected in sequence;

the third coil comprises at least fourteen first hairpin conductors which are connected in sequence.

In some embodiments, the first coil is disposed around a stator of the electric machine

The coils are distributed on a first layer and a second layer of different stator slots in a clockwise direction; wherein the second hairpin conductor is located on a first layer and a second layer;

the second coil is arranged around the motor stator

A first ring arranged on the first layer and the second layer of different stator slots in clockwise direction, and a second ring arranged on the second layer in clockwise directionThe third layer and the fourth layer are distributed on different stator slots, and the like, the second layer

The rings are distributed on the N-1 th layer and the N-th layer of different stator slots in the clockwise direction; the third hairpin lead is positioned on the (N-1) th layer and the Nth layer;

the third coil is arranged around the motor stator

The first ring is distributed on the Nth layer and the N-1 th layer of different stator slots in the anticlockwise direction, the second ring is distributed on the N-2 th layer and the N-3 th layer of different stator slots in the anticlockwise direction, and the like, and the second ring is distributed on the Nth layer and the N-1 th layer of different stator slots in the anticlockwise direction

The turns are distributed on the fourth layer and the third layer of different stator slots in a counterclockwise direction, and the last half turn is distributed on the second layer and the first layer of different stator slots in a counterclockwise direction.

In some embodiments, the pole pitch of each hairpin is 7 and the pitch of each hairpin is 5.

In some embodiments, each phase winding includes two parallel branches.

With reference to the first aspect, in one possible implementation manner, for any one of the in-slot conductor segments, there is another in-slot conductor segment corresponding to the in-slot conductor segment, so that the two in-slot conductor segments are located at the same position relative to the rotor magnetic pole and in different parallel branches of the same-phase winding.

Compared with the prior art, according to the scheme, each parallel branch comprises a plurality of first hairpin conductors, a second hairpin conductor and a third hairpin conductor, the hairpin welding sections of the second hairpin conductors and the third hairpin conductors can be connected with two first hairpin conductors on the same layer, the winding direction of the parallel branch is changed, two first hairpin conductors do not need to be connected through extra conductors, the star point line of the hairpin welding sections of the first hairpin conductors and the connection length of outgoing lines are reduced, the winding end structure is simplified, and the production efficiency is improved.

In a second aspect, an embodiment of the present invention further provides a stator assembly of an electric machine, including a stator core provided with a plurality of stator slots, and the above-mentioned three-phase stator winding penetrating in the plurality of stator slots.

With reference to the second aspect, in one possible implementation manner, the number of the stator slots is 48, 8 layers of hairpin conductors are stacked in each stator slot, and the stator core is configured to be used in a motor with a motor pole number of 8.

In a third aspect, an embodiment of the present invention further provides a motor, including the above motor stator assembly.

According to the motor stator assembly and the motor, due to the adoption of the three-phase stator winding, the star point lines and the occurring connection length of the hairpin welding section of the hairpin conductor can be reduced, the end welding is simplified, the production efficiency is improved, the end height of the winding is reduced, the using amount of copper wires is reduced, the resistivity is reduced, and the motor efficiency is improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed for the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is a schematic plan development view of an arrangement structure of three-phase stator windings according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a first card wire according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a second hairpin conductor provided by an embodiment of the utility model;

fig. 4 is a schematic structural diagram of a third hairpin conductor provided in an embodiment of the utility model;

fig. 5 is a schematic plan development view of an arrangement structure of one phase winding in three-phase stator windings according to an embodiment of the present invention;

fig. 6 is a schematic diagram of an arrangement structure of two parallel branches of one phase winding of three groups of stator windings under one pair of poles according to an embodiment of the present invention.

In the figure: 1. a first card-issuing wire; 11. a first in-slot wire segment; 12. a first hairpin insertion segment; 13. a first hairpin welding section; 2. a second hairpin conductor; 21. a second in-slot wire segment; 22. a second hairpin insertion section; 23. a second hairpin welding section; 3. a third hairpin conductor; 31. a third in-slot wire segment; 32. a third hairpin insertion section; 33. and a third hairpin welding section.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the utility model and are not intended to limit the utility model.

Referring to fig. 1 to 6 together, a three-phase stator winding according to the present invention will now be described. The three-phase stator winding comprises an A-phase winding, a B-phase winding and a C-phase winding, each phase winding comprises a plurality of parallel branches, N layers of hairpin conductors are superposed on each parallel branch, and N is more than or equal to 4 and is an even number; the N layers of the card sending leads of each parallel branch comprise a plurality of first card sending leads 1, a second card sending lead 2 and a third card sending lead 3; the second hairpin conductor 2 is connected between two first hairpin conductors 1 of the same layer, and the third hairpin conductor 3 is connected between two first hairpin conductors 1 of the same layer.

Each hairpin conductor comprises two in-slot conductor segments penetrating into different stator slots, a hairpin inserting segment positioned outside the stator slots and connected to one end of each in-slot conductor segment, and two hairpin welding segments positioned outside the stator slots and respectively connected to the other ends of the two in-slot conductor segments; the hairpin welding section and the in-groove conductor section are arranged at an included angle.

Specifically, the first hairpin conductor 1 includes two first in-slot conductor segments 11, a first hairpin insertion segment 12, and two first hairpin bonding segments 13, the second hairpin conductor 2 includes two second in-slot conductor segments 21, a second hairpin insertion segment 22, and two second hairpin bonding segments 23, and the third hairpin conductor 3 includes two third in-slot conductor segments 31, a third hairpin insertion segment 32, and two third hairpin bonding segments 33, as shown in fig. 2, 3, and 4.

Wherein, the two first hairpin welding segments 13 extend in opposite directions, the two second hairpin welding segments 23 extend in the same direction, the two third hairpin welding segments 33 extend in the same direction, and the extending direction of the second hairpin welding segments 23 is opposite to the extending direction of the third hairpin welding segments 33.

The second hairpin conductor 2 is connected between two first hairpin conductors 1 in the same layer, that is, the radial distance from the second in-slot conductor segment 21 to the central axis of the stator core is equal to the radial distance from the two first in-slot conductor segments 11 of the first hairpin conductor 1 connected with the second hairpin conductor 2 to the central axis of the stator core. The same applies to the third hairpin conductor 3.

Compared with the prior art, the three-phase stator winding provided by the utility model has the advantages that the hairpin welding sections of the second hairpin conductor 2 and the third hairpin conductor 3 can be connected with the two first hairpin conductors 1 on the same layer to change the winding direction of the parallel branch, so that the two first hairpin conductors 1 are not required to be connected by means of extra conductors, the star point lines of the hairpin welding sections of the first hairpin conductors 1 and the connection length of outgoing lines are reduced, the end structure of the winding is simplified, and the production efficiency is improved.

In order to further simplify the end winding structure of the stator, the hairpin welding sections can be arranged along the circumferential extension of the stator core, and cannot cross over the end area of the rotor, so that the hairpin welding sections are prevented from interfering with the rotor or other stator structures. In addition, in actual production, the second hairpin conductor 2 and the third hairpin conductor 3 can be obtained by reversely twisting one of the hairpin welding sections of the first hairpin conductor 1, so that the types of the hairpin conductors are few, the required dies are reduced, the production efficiency can be improved, and the cost can be reduced.

Specifically, in practical application, two first hairpin welding sections 13 of the first hairpin conductor 1 are symmetrically arranged; the two second hairpin welding sections 23 of the second hairpin conductor 2 are arranged in parallel, and the two third hairpin welding sections 33 of the third hairpin conductor 3 are arranged in parallel.

In some embodiments, for any one in-slot wire segment, there is another in-slot wire segment corresponding thereto, such that the two in-slot wire segments are in the same position relative to the rotor poles and are located in different parallel branches of the same phase winding.

In the same phase winding, for any two in-slot conductor segments belonging to different parallel branches, no voltage difference exists between the two in-slot conductor segments theoretically, but because the positions of the two in-slot conductor segments in the traditional motor relative to the rotor magnetic pole are not necessarily the same, when the relative positions are different, the influence of the magnetic field of the rotor magnetic pole on the two in-slot conductor segments can be different, so that the voltage difference exists between the two in-slot conductor segments, and a circulating current is formed between the two in-slot conductor segments. The existence of the circulation can increase the additional copper loss and the dragging loss of the motor, reduce the efficiency of the motor and seriously affect the rated performance of the motor.

Therefore, in order to solve the problem of circulating current, the stator of this embodiment uses a winding method to make any one of the in-slot conductor segments have another in-slot conductor segment corresponding to the in-slot conductor segment, and the corresponding relationship is: the two in-slot wire segments are located in the same position relative to the rotor poles and in different parallel branches of the in-phase winding, as shown in fig. 6. Because the influence of the magnetic poles of the rotor is the same, no voltage difference exists between the conductor segments in the two slots, and therefore no circulation is generated, and in the whole, because the position corresponding relation exists between the conductor segments in all the slots, circulation can be prevented from being generated among a plurality of parallel branches of each phase of winding, so that the additional copper loss and the dragging loss of the motor are reduced, and the efficiency and the rated performance of the motor are improved.

In order to further simplify the winding mode of the parallel circuit, the parallel circuit can be divided into a first coil, a second coil and a third coil which are connected in sequence; the first coil comprises at least one first hairpin conductor 1 and a second hairpin conductor 2 which are connected in sequence; the second coil comprises at least fifteen first card sending leads 1 and at least fifteen third card sending leads 3 which are connected in sequence; the third coil comprises at least fourteen first card wires 1 which are connected in sequence.

Wherein the first coil is arranged around the motor stator

The coils are distributed on a first layer and a second layer of different stator slots in a clockwise direction; the second hairpin conductors 2 are located at the first layer and the second layer.

The second coil is arranged around the stator of the motor

The first ring is distributed on the first layer and the second layer of different stator slots in the clockwise direction, the second ring is distributed on the third layer and the fourth layer of different stator slots in the clockwise direction, and so on

The ring is distributed on the N-1 th layer and the N-th layer of different stator slots in the clockwise direction; wherein, the third hairpin conductor 3 is located at the (N-1) th layer and the Nth layer.

The third coil is arranged around the stator of the motor

The first ring is distributed on the Nth layer and the N-1 th layer of different stator slots in the anticlockwise direction, the second ring is distributed on the N-2 th layer and the N-3 th layer of different stator slots in the anticlockwise direction, and so on, and the second ring is distributed on the Nth layer and the N-1 th layer of different stator slots in the anticlockwise direction

The turns are distributed in the fourth and third layers of different stator slots in a counter-clockwise direction, and the last half turn is distributed in the second and first layers of different stator slots in a counter-clockwise direction.

Briefly, the parallel branches in this embodiment are arranged in the following manner: counterclockwise half turn, clockwise

Circle and anticlockwise

Circle, counterclockwise half-circle.

As will be explained in more detail with reference to fig. 1, 5 and 6, the stator in the figures is a stator in a 48-slot 8-pole motor, that is, the stator core 1 of the stator includes 48 stator slots, and all the stator slots are numbered sequentially, and the number of rotor poles is 8 (that is, the number of pole pairs is 4). In addition, the winding comprises 8 layers of hairpin conductors, which are defined as the 1 st layer to the 8 th layer in the same stator slot from inside to outside along the radial direction. In fig. 1, the middle row of numbers represents the number of stator slots, and eight lines from left to right in each slot correspond to the 1 st to 8 th layers, respectively.

As shown in fig. 5, each phase winding includes two parallel branches, three hairpin conductors, namely, a first hairpin conductor 1, a second hairpin conductor 2, and a third hairpin conductor 3, are used for winding in the three-phase stator winding, the pole pitch of the three hairpin conductors is 7, and the pitch is 5. The three hairpin conductors are all different-layer overlines. The different-layer overline means: the two in-slot conductor segments in the same hairpin conductor are positioned in different layers except for penetrating into different stator slots.

Taking the B-phase winding as an example, specifically, the B-phase winding includes a branch B1 and a branch B2.

The positions of a plurality of stator slots corresponding to the in-slot conductor segments of the plurality of hairpin conductors of the branch B1 are as follows:

9 groove 2 layer, 16 groove 1 layer, 21 groove 2 layer, 28 groove 1 layer, 23 groove 1 layer, 16 groove 2 layer, 11 groove 1 layer, 4 groove 2 layer, 47 groove 1 layer, 40 groove 2 layer, 35 groove 1 layer, 28 groove 2 layer, 23 groove 3 layer, 16 groove 4 layer, 11 groove 3 layer, 4 groove 4 layer, 47 groove 2 layer, 40 groove 4 layer, 35 groove 3 layer, 28 groove 4 layer, 23 groove 5 layer, 16 groove 6 layer, 11 groove 5 layer, 4 groove 6 layer, 47 groove 5 layer, 40 groove 6 layer, 35 groove 5 layer, 28 groove 6 layer, 23 groove 7 layer, 16 groove 8 layer, 11 groove 7 layer, 4 groove 8 layer, 47 groove 7 layer, 40 groove 8 layer, 35 groove 7 layer, 28 groove 8 layer, 33 groove 8 layer, 40 groove 7 layer, 45 groove 8 layer, 4 groove 7 layer, 9 groove 8 layer, 16 groove 7 layer, 21 groove 8 layer, 28 groove 7 layer, 28 groove 6 layer, 33 groove 5 layer, 6 layer, 9 groove 5 groove 6 layer, 21 groove 6 layer, 6 groove 5 layer, 4 groove 6 layer, 40 groove 6 layer, 9 groove 6 layer, 9 groove 5 layer, 40 groove 6 layer, 9 groove 5 groove 6 layer, 4 groove 6 layer, 6 groove 6 layer, 4 groove layer, 6 groove layer, 6 groove layer, 4 groove layer, 6 groove layer, and the like, 33 groove 4 layer, 40 groove 3 layer, 45 groove 4 layer, 4 groove 3 layer, 9 groove 4 layer, 16 groove 3 layer, 21 groove 4 layer, 28 groove 3 layer, 33 groove 2 layer, 40 groove 1 layer, 45 groove 2 layer, 4 groove 1 layer.

Wherein, the in-slot conductor segment in slot 2 of 21 slots and the in-slot conductor segment in slot 1 layer of 28 slots are two second in-slot conductor segments 21 respectively. The in-slot conductor segments in the 35 slot 7 layer and the in-slot conductor segments in the 28 slot 8 layer are the two third in-slot conductor segments 31, respectively.

The positions of a plurality of stator slots corresponding to the in-slot conductor segments of the plurality of hairpin conductors of the branch B2 are as follows:

10 groove 2 layer, 17 groove 1 layer, 22 groove 2 layer, 29 groove 1 layer, 34 groove 1 layer, 27 groove 2 layer, 22 groove 1 layer, 15 groove 2 layer, 10 groove 1 layer, 3 groove 2 layer, 46 groove 1 layer, 39 groove 2 layer, 34 groove 3 layer, 27 groove 4 layer, 22 groove 3 layer, 15 groove 4 layer, 10 groove 3 layer, 3 groove 4 layer, 46 groove 3 layer, 39 groove 4 layer, 34 groove 5 layer, 27 groove 6 layer, 22 groove 5 layer, 15 groove 6 layer, 10 groove 5 layer, 3 groove 6 layer, 46 groove 5 layer, 39 groove 6 layer, 34 groove 7 layer, 27 groove 8 layer, 22 groove 7 layer, 15 groove 8 layer, 10 groove 7 layer, 3 groove 8 layer, 46 groove 7 layer, 39 groove 8 layer, 34 groove 8 layer, 41 groove 7 layer, 46 groove 8 layer, 5 groove 7 layer, 10 groove 8 layer, 17 groove 7 layer, 22 groove 8 layer, 29 groove 7 layer, 29 groove 6 layer, 29 groove 5 groove 6 layer, 22 groove 5 groove 6 layer, 17 groove 6 layer, 22 groove 6 layer, 9 groove 7 layer, 9 groove 6 layer, 9 groove 6 groove layer, 9 groove 6 groove layer, 9 groove 7 layer, 9 groove 7 groove 6 groove layer, 9 groove 7 groove layer, 9 groove layer, 6 groove layer, 9 groove 7 layer, 9 groove 6 groove layer, 9 groove 6 groove layer, 9 groove 6 groove layer, 9 groove 6 groove layer, 9 groove 7 layer, 9 groove 6 groove layer, 9 groove 6 groove layer, 9 groove 7 layer, 9 groove 7 layer, 9 groove 6 groove layer, 9 groove 6 groove, 34 groove 4 layer, 41 groove 3 layer, 46 groove 4 layer, 5 groove 3 layer, 10 groove 4 layer, 17 groove 3 layer, 22 groove 4 layer, 29 groove 3 layer, 34 groove 2 layer, 41 groove 1 layer, 46 groove 2 layer, 5 groove 1 layer.

Wherein the intra-slot conductor segment in the 22 slot 2 slot and the intra-slot conductor segment in the 29 slot 1 layer are two second intra-slot conductor segments 21, respectively. The in-slot conductor segments in the layer 46 slot 7 and the in-slot conductor segments in the layer 39 slot 8 are the two third in-slot conductor segments 31, respectively.

It should be noted that, since the arrangement of the in-slot conductor segments between the parallel branches under each two pairs of rotor magnetic poles is the same, the embodiment only analyzes the arrangement of the in-slot conductor segments between the parallel branches under two pairs of rotor magnetic poles. For the analysis of the parallel branches of the a-phase winding and the C-phase winding, reference may be made to the B-phase winding, and for the sake of brevity, no specific description is made here.

Based on the same inventive concept, the embodiment of the utility model also provides a motor stator assembly, which comprises a stator core provided with a plurality of stator slots and the three-phase stator winding penetrating into the stator slots. The number of the stator slots is 48, 8 layers of hairpin conductors are superposed in each stator slot, and the stator core is matched with a motor with the number of poles of 8.

Based on the same inventive concept, the embodiment of the utility model also provides a motor, which comprises the motor stator assembly.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the utility model, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. A three-phase stator winding comprises an A-phase winding, a B-phase winding and a C-phase winding, wherein each phase winding comprises a plurality of parallel branches, N layers of hairpin conductors are superposed on each parallel branch, and N is more than or equal to 4 and is an even number; the parallel connection structure is characterized in that the N layers of hairpin conductors in each parallel branch comprise a plurality of first hairpin conductors, a second hairpin conductor and a third hairpin conductor; the second hairpin conductor is connected between the two first hairpin conductors positioned on the same layer, and the third hairpin conductor is connected between the other two first hairpin conductors positioned on the same layer;

2. The three-phase stator winding as claimed in claim 1 wherein the two hairpin weld segments of the first hairpin conductor are symmetrically disposed; the two hairpin welding sections of the second hairpin conductor are arranged in parallel, and the two hairpin welding sections of the third hairpin conductor are arranged in parallel.

3. The three-phase stator winding according to claim 1, wherein each of the parallel branches includes a first coil, a second coil and a third coil which are connected in sequence;

4. A three-phase stator winding according to claim 3, wherein the first coil is disposed around the stator of the motor

A ring and distributed in a clockwise direction on a first layer and a second layer of different stator slots; wherein the second hairpin conductor is located on a first layer and a second layer;

the second coil is arranged around the motor stator

The first ring is distributed on the first layer and the second layer of different stator slots in the clockwise direction, the second ring is distributed on the third layer and the fourth layer of different stator slots in the clockwise direction, and the like, and the second ring is distributed on the third layer and the fourth layer of different stator slots in the clockwise direction

the third coil is arranged around the motor stator

The first ring is distributed on the Nth layer and the (N-1) th layer of different stator slots in the anticlockwise direction, the second ring is distributed on the N-2 th layer and the (N-3) th layer of different stator slots in the anticlockwise direction, and so on

5. The three-phase stator winding of claim 4, wherein the pole pitch of each hairpin is 7 and the pitch of each hairpin is 5.

6. The three-phase stator winding according to claim 5, wherein each phase winding includes two of said parallel branches.

7. A three-phase stator winding according to claim 1, wherein for any one of said in-slot wire segments there is another one of said in-slot wire segments corresponding thereto, such that the two said in-slot wire segments are located in the same position relative to the rotor poles and in different said parallel branches of the in-phase winding.

8. A stator assembly for an electrical machine comprising a stator core having a plurality of stator slots and a three-phase stator winding according to any one of claims 1 to 7 threaded into the plurality of stator slots.

9. The electric machine stator assembly of claim 8 wherein the number of stator slots is 48, each stator slot having 8 layers of hairpin conductors superimposed therein, the stator core configured to match use with an electric machine having an 8 pole count.

10. An electric machine comprising the electric machine stator assembly of claim 9.