Stator assembly, electric motor and vehicle

Abstract

The present invention relates to the technical field of vehicles. Provided are a stator assembly, an electric motor and a vehicle. The stator assembly comprises a stator core and windings of multiple phases that surround the stator core, wherein a plurality of stator slots are provided in the stator core in the circumferential direction of the stator core; each stator slot has M slot layers arranged in the radial direction of the stator core; windings of each phase each comprise N branches connected in parallel; each branch comprises a first coil section and a second coil section which are connected; the first coil section and the second coil section each comprise Q winding portions and Q connecting sections; the Q winding portions are arranged in the circumferential direction of the stator core; each connecting section connects two adjacent winding portions, such that the winding portions and the connecting section form a plurality of variable-pitch units in the corresponding slot layers; and the slot layers corresponding to the two adjacent winding portions are the same layer, adjacent layers or separated layers. The sizes of end portions of windings of a stator core are reduced, welding spots are avoided, the structure and sizes are compact, the potentials of branches are balanced, and loop currents are avoided.

Description

Stator assembly, motor and vehicle

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on August 28, 2023, with application number 202311092467.9 and application name “Stator Assembly, Motor and Vehicle”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The embodiments of the present invention relate to, but are not limited to, the field of vehicle technology, and in particular to a stator assembly, a motor, and a vehicle. Background Art

[0003] Electric vehicles offer advantages over traditional fuel-powered vehicles in terms of power, intelligence, and cost. However, their long charging times limit their widespread adoption. To improve EV range and the power density of their drive systems, flat-wire motors are typically used. The stator assembly of a flat-wire motor consists of a stator core and multiphase windings. The stator core is circumferentially arranged with multiple stator slots, each containing multiple layers of conductors forming the multiphase windings.

[0004] The conductive wire has a plurality of lead ends relative to the stator core, and the plurality of lead ends need to be welded.

[0005] However, the welding process of the lead end of the wire is complicated and the lead end of the wire is long, resulting in high material loss, which affects the power generation efficiency of the motor.

[0006] Summary of the Invention

[0007] The present invention provides a stator assembly, a motor and a vehicle, wherein the end size of the wire winding on the stator core is small, the winding structure is compact and the lead end is convenient to connect.

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] A first aspect of the present invention provides a stator assembly for use in an electric motor, the stator assembly comprising a stator core and a multi-phase winding wound around the stator core, the stator core being circumferentially provided with a plurality of stator slots, each of the stator slots having M slot layers arranged radially of the stator core, where M is greater than or equal to 4 and is an even number;

[0010] Each phase of the winding includes N parallel branches, and each branch includes a first coil segment and a second coil segment connected to each other; the first coil segment is wound around the stator core M / 2 times in a first direction, and the second coil segment is wound around the stator core M / 2 times in a second direction, where N is less than or equal to M, and the first direction and the second direction are different;

[0011] Each of the first coil segment and the second coil segment includes Q winding portions and Q connecting segments. The Q winding portions are arranged along the circumference of the stator core. Each connecting segment connects two adjacent winding portions, so that the winding portions and the connecting segments form a plurality of variable pitch units within corresponding slot layers. Q = M * P, where P is the number of pole pairs of the motor. The slot layers corresponding to two adjacent winding portions are either the same layer, adjacent layers, or alternate layers.

[0012] The multiple variable-pitch units include one or more of short-pitch units, full-pitch units and long-pitch units, the span of the short-pitch unit is smaller than the pole pitch of the motor, the span of the full-pitch unit is equal to the pole pitch of the motor, and the span of the long-pitch unit is larger than the pole pitch of the motor.

[0013] The stator assembly provided by the embodiment of the present invention has at least the following beneficial effects:

[0014] By winding a continuous winding around the stator slots of the stator core, specifically utilizing the specific winding direction and number of turns of the connected first coil segment and second coil segment along the outer circumference of the stator core, and controlling and changing the different types of winding pitches of the winding portions and connecting segments contained in the first coil segment and the second coil segment within the slot layer, a stator assembly containing a specific winding form is formed. Compared with the hairpin-shaped winding of the mainstream related technology, the length of the lead end extending from the end of the stator core is significantly reduced, thereby improving the convenience of wire connection.

[0015] In a possible implementation, the first coil segment and the second coil segment are connected via a connecting segment, and a winding direction of the connecting segment is the same as the first direction.

[0016] In a possible implementation manner, the first direction and the second direction are opposite.

[0017] In a possible implementation, the lead end of the first coil segment and the lead end of the second coil segment are located in the same slot layer.

[0018] In a possible implementation, the lead end of the first coil segment and the lead end of the second coil segment are located in the innermost layer or the outermost layer of the slot layer.

[0019] In a possible implementation, the span y1 of the short-pitch unit is τ-1 or τ-2, the span y1 of the long-pitch unit is τ+1 or τ+2, and the span y1 of the full-pitch unit is τ, where τ is the pole pitch of the motor.

[0020] In a possible implementation, the number of the stator slots is 54, the number of the magnetic poles is 6, and the pole pitch is 9.

[0021] In a possible implementation, the multi-phase winding is a three-phase symmetrical winding, the spatial phase difference between every two phases of the winding is 120°, and the conductor connection mode of the three-phase winding is star connection or delta connection.

[0022] A second aspect of the present invention provides a motor, comprising a stator assembly provided by any one of the technical solutions of the first aspect, wherein the stator assembly is installed inside the motor.

[0023] A third aspect of the present invention provides a vehicle, comprising the stator assembly provided by any one of the technical solutions of the first aspect installed in a motor of the vehicle or the motor provided by the second aspect connected to a transmission system of the vehicle.

[0024] The beneficial effects provided by the second and third aspects of the present invention are substantially the same as those provided by the first aspect of the present invention, and will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] FIG1 is a schematic structural diagram of a stator assembly provided in an embodiment of the present invention;

[0027] FIG2 is a schematic structural diagram of the lead end of the stator assembly in FIG1 ;

[0028] FIG3 is a schematic structural diagram of the non-lead end of the stator assembly in FIG1 ;

[0029] FIG4 is a schematic structural diagram of the stator slots on the stator core in FIG1 ;

[0030] FIG5 is a schematic structural diagram of the first branch of phase A in the multi-phase winding in FIG1 ;

[0031] FIG6 is a partial winding expansion diagram of the first branch of phase A in FIG5 ;

[0032] FIG7 is a cross-sectional view of three branches of phase A in the multi-phase winding in FIG1 ;

[0033] FIG8 is a partial winding expansion diagram of a three-phase winding in the multi-phase winding in FIG1 ;

[0034] FIG9 is a schematic diagram of phase belt distribution of a multi-phase winding according to an embodiment of the present invention;

[0035] FIG10 is a schematic diagram of the winding pattern of the first branch winding A1X1 of phase A in an embodiment of the present invention;

[0036] FIG11 is a schematic diagram of the winding pattern of the second branch winding A2X2 of phase A in an embodiment of the present invention;

[0037] FIG12 is a schematic diagram of the winding pattern of the third branch winding A3X3 of phase A in an embodiment of the present invention;

[0038] FIG13 is a schematic diagram of a three-phase winding star connection according to an embodiment of the present invention;

[0039] FIG14 is a schematic diagram of a three-phase winding angular connection according to an embodiment of the present invention;

[0040] FIG15 is a schematic diagram of a structure of a circulating current simulation verification circuit according to an embodiment of the present invention;

[0041] FIG16 is a diagram showing the current results of three branches of phase A according to an embodiment of the present invention;

[0042] FIG17 is a diagram showing the circulation results of the three branches of phase A in an embodiment of the present invention.

[0043] Explanation of the accompanying reference numerals: 100 - stator core; 110 - stator slot; 111 - adjacent slot layer; 112 - alternate slot layer; 200 - multi-phase winding; 210 - lead end; 220 - non-lead end; 230 - A-phase winding; 231 - winding portion; 232 - connecting section; 233 - full-pitch unit; 234 - short-pitch unit; 235 - long-pitch unit; 240 - three-phase winding. DETAILED DESCRIPTION

[0044] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0045] As mentioned in the background, the stator assembly is a crucial component of electric motors. In electric vehicles, motors must meet requirements for lightweight, high power density, and high efficiency. Currently, flat wire motors are widely used as the mainstream winding format. Compared to round wire motors, flat wire offers a higher slot fill factor. This means that, given a constant size and number of stator slots, more copper wire can be filled into the stator slots, allowing them to pass greater current, generate a stronger magnetic field, and ultimately improve power density.

[0046] In the related art, the winding form of flat wire motors is mainly hairpin winding. After it is connected to the stator core, the lead ends extending relative to the end of the stator core need to be welded. This leads to the problem of long lead ends and large end material loss. The inventors have found that the main reason for this problem is that the hairpin-shaped hairpin winding in the related art needs to be formed before being inserted into the stator slots of the stator core. The leads of the winding lead ends need to be welded together. However, under this method, the lead ends extending relative to the end of the stator core are relatively long. Specifically, the leads of the lead ends are circumferentially spaced and located at different slot layers of the stator core and / or the stator slots of the stator core. This results in an unreasonable distribution layout of the lead ends, which is not conducive to the subsequent welding process.

[0047] An embodiment of the present invention provides a stator assembly, which is formed by a continuous winding wound on the stator slots of the stator core. Specifically, the stator assembly uses a specific winding direction and number of turns of a connected first coil segment and a second coil segment along the outer circumference of the stator core, and controls and changes the different types of winding pitches of the winding portions and connecting segments included in the first coil segment and the second coil segment within the slot layer, thereby forming a stator assembly including a specific winding form. Compared with the hairpin winding of the mainstream related technology, the length of the lead end extending from the end of the stator core is significantly reduced, thereby improving the convenience of wire connection.

[0048] Moreover, the above-mentioned winding method enables the windings arranged in the same stator slot to all belong to the same phase, thereby eliminating the insulating paper that isolates the windings of different phases arranged in the same stator slot, improving the slot fill rate of the motor, thereby improving the power density of the motor, and reducing the insulation cost of the motor. In addition, the above-mentioned winding method can also make the magnetic circuits of each branch in each phase winding completely symmetrical, eliminating the circulation problem caused by the asymmetric structure, improving the efficiency of the motor, and reducing the temperature rise of the motor. Moreover, since the insulating paper in the same stator slot is eliminated, the wire insertion process of the multi-phase winding is simplified, the manufacturing efficiency of the motor is improved, and the insulation cost of the motor is reduced.

[0049] Exemplary embodiments will be described in detail herein, examples of which are illustrated in the accompanying drawings. When the following description refers to the drawings, identical numbers in different figures represent identical or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Instead, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0050] In order to make the above-mentioned purposes, features and advantages of the embodiments of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0051] First, relevant technical terms in the motor involved in the embodiments of the present application are explained and illustrated.

[0052] The number of motor poles, that is, the number of magnetic poles of the motor. The magnetic poles are divided into N poles and S poles. Generally, one N pole and one S pole are called a pair of magnetic poles, that is, the number of pole pairs (P) of the motor is 1.

[0053] The number of slots per pole per phase, the number of slots occupied by each phase winding under each magnetic pole is called the number of slots per pole per phase.

[0054] The number of phases in a motor generally refers to the number of phase wires (also known as live wires). For example, a three-phase motor uses three phase wires. The number of phases is usually defined by the number of output terminals on the motor's stator side (excluding the neutral wire).

[0055] The phase belt of the motor is the number of slots on the stator core that are continuously occupied by each pole and each phase winding.

[0056] The slot fill rate refers to the ratio of the conductor cross-sectional area in the slot of the designated core to the effective area of ​​the slot body.

[0057] The pole pitch of the motor is the distance between two adjacent magnetic poles along the surface of the stator core.

[0058] The span, also known as the pitch, refers to the distance between the two effective sides of the same conductor in the winding of the motor on the armature surface, usually expressed in the number of slots.

[0059] Full pitch means the pitch is equal to the pole pitch; short pitch means the pitch is smaller than the pole pitch; long pitch means the pitch is larger than the pole pitch.

[0060] In a first aspect, with reference to FIG1 , FIG2 , FIG3 , and FIG4 , an embodiment of the present invention provides a stator assembly for use in a motor. The stator assembly includes a stator core 100 and a multi-phase winding 200 wound around the stator core 100 . The stator core 100 is provided with a plurality of stator slots 110 along its circumference. Each stator slot 110 has M slot layers arranged radially along the stator core 100 , where M is greater than or equal to 4 and is an even number.

[0061] Each phase winding includes N parallel branches, and each branch includes a first coil segment and a second coil segment connected to each other; a line segment of the first coil segment is wound around the stator core 100M / 2 turns in a first direction, and a line segment of the second coil segment is wound around the stator core 100M / 2 turns in a second direction, wherein the first direction and the second direction are different, and wherein N is less than or equal to M;

[0062] Each of the first coil segment and the second coil segment includes Q winding portions 231 and Q connecting segments 232. The Q winding portions 231 are arranged along the circumference of the stator core 100. Each connecting segment 232 connects two adjacent winding portions 231, so that the winding portions 231 and the connecting segments 232 form a plurality of variable pitch units in the corresponding slot layers, wherein Q = M / 2*2P = M*P, and P is the number of pole pairs of the motor; the slot layers corresponding to the two adjacent winding portions 231 are one of the same layer, adjacent layers, or alternate layers. For example, with reference to Figures 10 to 12, the adjacent slot layers 111 can be layer a and layer b, and the alternate slot layers 112 can be layer b and layer d, or layer d and layer f, or can be any other two slot layers separated by one layer or multiple layers.

[0063] The multiple variable pitch units include one or more of a short pitch unit 234, a full pitch unit 233 and a long pitch unit 235, wherein the span of the short pitch unit 234 is smaller than the pole pitch of the motor, the span of the full pitch unit 233 is equal to the pole pitch of the motor, and the span of the long pitch unit 235 is larger than the pole pitch of the motor.

[0064] In this way, by winding the continuous winding on the stator slots of the stator core, specifically utilizing the specific winding direction and number of turns of the connected first coil segment and the second coil segment along the outer circumference of the stator core, and controlling the change of the different types of winding pitches of the winding portion 231 and the connecting segment 232 contained in the first coil segment and the second coil segment in the slot layer, a stator assembly containing a specific winding form is formed. Compared with the hair-pin winding of the mainstream related technology, the size of the winding end is reduced, and the non-lead end 220 does not need to be welded, which also improves the convenience of subsequent wire connection of the lead end.

[0065] Continuing with FIG4 , the stator slot 110 may have six slot layers. From the slot bottom toward the slot opening, the six slot layers may be, in order, layer a, layer b, layer c, layer d, layer e, and layer f. For example, layer a, or the first slot layer, is located at the innermost side of the stator slot 110, and layer f, or the sixth slot layer, is located at the outermost side of the stator slot 110. It is understood that layer a may also be located at the outermost side of the stator slot 110, and layer f may also be located at the innermost side of the stator slot 110. It should be noted that a slot layer can be understood as the space for winding wiring sequentially arranged in the slot depth direction within the same stator slot 110. This space may be a virtual space within the stator slot 110 to facilitate description of the position of the winding in the stator slot 110 in the slot depth direction when the winding is routed within the stator slot 110.

[0066] It should be noted that the multi-phase winding 200 is a plurality of phase windings, and the plurality of phase windings are different in electrical phase. For example, the multi-phase winding 200 may be a three-phase winding 240. The three-phase winding 240 may have the same winding pattern on the stator core 100 and may differ in spatial phase by 120°. In other words, the multi-phase winding 200 may include three phase windings, such as an A-phase winding 230, a B-phase winding, and a C-phase winding. The three-phase winding 240 may be connected in a star configuration or a delta configuration.

[0067] For example, the first direction may be a clockwise direction when viewed from the lead end 210, and the second direction may be a counterclockwise direction when viewed from the lead end 210. It is understood that the first direction and the second direction may also be interchangeable.

[0068] As a possible embodiment, the first coil segment and the second coil segment are connected by a connecting segment, and the winding direction of the connecting segment is the same as the first direction. For example, in conjunction with Figures 5, 6 and 10, the first direction is the counterclockwise direction along the circumference of the stator core. In the first branch A1X1 of winding phase A, the first coil segment is wound into the first stator slot of slot layer a and then wound three times in the counterclockwise direction to 47f, that is, the 47th stator slot of slot layer f. The connecting segment is the coil segment between 47f and 3f, and its winding direction is the same as the first direction, also in the counterclockwise direction. This design facilitates reducing the length of the lead end 210 of the second coil segment extending along the stator slot and facilitates its arrangement on the same layer as the lead end 210 of the first coil segment extending into the stator slot. The end of the stator core 100 opposite the lead end 210 is the non-lead end 220.

[0069] In some embodiments, the first direction and the second direction are opposite. In combination with Figures 10, 11 and 12, the winding layout of the three branches is that the first coil segment wound around the stator core three times in the first direction is connected to the second coil segment wound around the stator core three times in the opposite direction of the first direction. In this way, by winding the first coil segment and the second coil segment of a single branch around the stator core in opposite directions, a specific optimization effect is achieved on the wire winding layout, which further helps to reduce the size of the lead end 210.

[0070] In more possible embodiments, referring to Figures 1 and 2, the lead end 210 of the first coil segment and the lead end 210 of the second coil segment are located in the same slot layer. With this design, compared with arrangements in different layers, the multiple leads of the lead end 210 arranged in the same layer significantly improve the process convenience of their subsequent connection. Moreover, the lead ends 210 of the multiple first coil segments and the lead ends 210 of the multiple second coil segments of the multi-phase and multi-branch circuit are all located in the same slot layer and arranged adjacent to each other along the circumference of the stator core, further improving the connection convenience of the winding and reducing the size of the lead end 210 of the multi-phase winding 200.

[0071] On the basis of the above embodiment, what can be improved is that the lead end 210 of the first coil segment and the lead end 210 of the second coil segment are located in the innermost layer or the outermost layer in the slot layer. Referring to Figures 4 and 9-12, the lead end 210 of the first coil segment and the lead end 210 of the second coil segment are located in layer a or layer f. The lead ends 210 are both arranged in the innermost or outermost layer of the slot layer. Compared with other layers, it is convenient for the connection operation between the leads and is beneficial to the stability of current transmission after the line is turned on.

[0072] In some embodiments, the span y1 of the short-distance unit 234 is τ-1 or τ-2, and the span y1 of the long-distance unit 235 is τ+1 or τ+2, where τ is the pole pitch of the motor. For example, the pole pitch τ is 9. Combined with Figure 10, 12e→1e spans a long-distance unit 235, and the long-distance unit 235 is τ+2=11; combined with Figure 11, 10e→2e spans a short-distance unit 234, and the short-distance unit 234 is τ-1=8. In this way, the diversity of the pitch unit scale is further ensured to further ensure the minimization of the size of the lead end 210 after the winding is wound around the stator core and simplify the winding arrangement.

[0073] It should be noted that the first coil segment and the second coil segment are wound multiple times on the stator core 100 , and the total number of turns of the first coil segment and the second coil segment needs to be adjusted according to the number of stator slots 110 and the pole pitch of the motor.

[0074] As a possible implementation, referring to Figures 13 and 14, the multi-phase winding 200 includes a three-phase winding 240, the spatial phase difference between each two-phase winding is 120°, and the wire connection method of the three-phase winding 240 is star connection or delta connection to meet the different electrical characteristics, torque output and efficiency requirements of the motor.

[0075] To facilitate understanding of the technical solution of the embodiment of the present application, the technical solution of the embodiment of the present application will be described below by taking a multi-phase winding 200 in which the number of phases m is 3, the number of poles 2P is 6, the number of slots Q of the stator slots 110 is 54, the number of slot layers M of each stator slot 110 is 6, the number of slots per pole per phase q is 3, the pole pitch τ is 9, and each phase winding includes 3 branches as an example.

[0076] First, the phase bands of the multi-phase winding 200 are divided. A schematic diagram of the phase band division is shown in FIG9 .

[0077] 12 to 16 , the first winding portion 231 of the first branch A1X1 of the A-phase may enter from the slot layer a of the first stator slot 110 corresponding to the first magnetic pole (i.e., 1a), and be gradually wound along the first direction around the circumference of the stator core 100 to the slot layer b of the 46th stator slot 110 with different spans (the number of slots spanned between two adjacent winding portions 231, for example, 28b→37a, the span is 9, which is a full pitch τ); then, the winding continues along the first direction for two turns to the slot layer f corresponding to the 47th stator slot 110, then, through the connecting section leading to the first coil segment, it is wound to 3f, then, in the reverse direction, it is wound three times according to a regular pattern to 12a, and then, it is led out from the corresponding stator slot 110. The specific winding method of the first branch A1X1 is as follows:

[0078] Referring to Figure 10,

[0079] 1a→10b→19a→28b→37a→46b→2b→11d→20c→29d→38c→47d→2d→11f→20e→29f→38e→47f→3f→48e→39f→30e→21f→12e→1e→46c→37d→28c→19d→10c→3c→48a→39b→30a→21b→12a→.

[0080] It should be noted that the first coil segment is a line segment:

[0081] 1a→10b→19a→28b→37a→46b→2b→11d→20c→29d→38c→47d→2d→11f→20e→29f→38e→47f.

[0082] The second coil segment is a line segment:

[0083] 3f→48e→39f→30e→21f→12e→1e→46c→37d→28c→19d→10c→3c→48a→39b→30a→21b→12a.

[0084] The connected segment is a line segment between 47f and 3f, and the total number of turns of the first coil segment and the second coil segment are 3 respectively.

[0085] Referring to Figure 11, the winding method of the second branch A2X2 is as follows:

[0086] 2a→11b→20a→29b→38a→47b→3b→12d→21c→30d→39c→48d→3d→12f→21e→30f→39e→48f→1f→46e→37f→28e→19f→10e→2e→47c→38d→29c→20d→11c→1c→46a→37b→28a→19b→10a→, where the first coil segment is 2a→11b→20a→29b→38a→ The line segment is 47b→3b→12d→21c→30d→39c→48d→3d→12f→21e→30f→39e→48f, the connected segment is the line segment between 48f→1f, the second coil segment is the line segment between 1f→46e→37f→28e→19f→10e→2e→47c→38d→29c→20d→11c→1c→46a→37b→28a→19b→10a→, and the total number of turns of the first coil segment and the second coil segment are 3 respectively.

[0087] Referring to Figure 12, the winding method of the third branch A3X3 is as follows:

[0088] 3a→12b→21a→30b→39a→48b→1b→10d→19c→28d→37c→46d→1d→10f→19e→28f→37e→46f→2f→47e→38f→29e→20f→11e→3e→48c→39d→30c→21d→12c→2c→47a→38b→29a→20b→11a→, where the first coil segment is 3a→12b →21a→30b→39a→48b→1b→10d→19c→28d→37c→46d→1d→10f→19e→28f→37e→46f, the connected segment is the line segment between 46f→2f, and the second coil segment is 2f→47e→38f→29e→20f→11e→3e→48c→39d→30c→21d→12c→2c→47a→38b→29a→20b→11a→.

[0089] 7 and 8 , the winding expansion diagrams respectively show the expansion diagram and the three-phase expansion diagram of the A-phase winding 230. The B-phase winding and the C-phase winding are wound in the same manner as the A-phase winding 230, with a spatial phase difference of 120°. Specifically, B is shifted by q (i.e., 3) stator slots 110 relative to the A-phase, and C is shifted by q stator slots 110 relative to the B-phase.

[0090] 13 and 14 , the A-phase winding 230 , the B-phase winding, and the C-phase winding may be connected in a star configuration or in a delta configuration.

[0091] The winding method of the present invention significantly reduces the size of the lead end 210 and allows each branch to traverse the designated phase band and slot layer. This balances the potential of each branch and eliminates circulating current between branches, improving motor efficiency and reducing motor temperature rise. Furthermore, since conductors within the same stator slot 110 belong to the same phase, insulating paper is not required between them. This improves the slot fill factor, increases the motor's power density, and reduces insulation costs.

[0092] Combined with the circulating current simulation of Figures 15, 16 and 17, the relevant experiments and results are verified. The experiment is carried out by finite element software field-circuit coupling simulation. Phase A is passed 570Arms (ampere effective value). The three branch currents of phase A are shown in Figure 16. The currents of the three branches on the surface are basically symmetrical, and the effective values ​​of the currents are 192.32Arms, 192.54Arms, and 193.12Arms respectively. The difference between the effective values ​​of the single-phase branch currents in the winding form in the related art is large, that is, the generated branch currents are relatively stable. The circulating currents Ia12, Ia13, and Ia23 are relatively large. On the other hand, the branch circulating currents measured in the embodiment of the present invention are shown in FIG17 . The effective values ​​of the branch circulating currents are 1.00 Arms, 1.40 Arms, and 1.51 Arms, respectively. The circulating current is only 0.78% of the branch current. According to Ohm's law, the loss is proportional to the square of the current. Therefore, the branch circulating current intensity is very small and can be ignored. This verifies that the branches of the stator assembly provided in the embodiment of the present invention are symmetrical and have the same potential, which avoids the negative effects of the circulating current.

[0093] The stator assembly provided in the embodiments of the present application can be applied to electric vehicles / equipment (Electric Vehicle, referred to as EV), pure electric vehicle equipment (Pure Electric Vehicle / Battery Electric Vehicle, referred to as PEV / BEV), hybrid electric vehicles (Hybrid Electric Vehicle, referred to as HEV), range-extended electric vehicles (Range Extended Electric Vehicle, referred to as REEV), plug-in hybrid electric vehicles (Plug-in Hybrid Electric Vehicle, referred to as PHEV), and new energy vehicles (New Energy Vehicle).

[0094] In a second aspect, an embodiment of the present invention provides a motor, comprising a stator assembly provided by any scheme of the first aspect, wherein the protruding end of the winding wire of the stator assembly, i.e., the lead end, can be connected to the terminal box or control system of the motor to access power and control signals, and the connection method is plug-in or threaded connection to achieve a secure connection and ensure the normal operation of the motor.

[0095] In a third aspect, an embodiment of the present invention provides a vehicle, comprising the stator assembly provided by any one of the schemes in the first aspect or the motor provided by the second aspect, wherein the stator assembly is installed in the motor, and the motor is connected to a transmission system inside the vehicle to provide a stable driving force for the vehicle.

[0096] Therefore, the second and third aspects also have the advantages of the stator assembly of any scheme of the first aspect, and the embodiments of the present invention will not be described in detail.

[0097] In the description of the present invention, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0098] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0099] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0100] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0101] The various embodiments or implementation methods in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referenced to each other.

[0102] It should be noted that phrases such as "one embodiment," "an embodiment," "exemplary embodiment," and "some embodiments" in this specification may indicate embodiments that may include a particular feature, structure, or characteristic, but not every embodiment necessarily includes that particular feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in conjunction with an embodiment, it is within the knowledge of those skilled in the art to implement such feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not.

[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

[0104] Still other aspects will become apparent upon reading and understanding the accompanying drawings and detailed description.

Claims

1. A stator assembly, comprising a stator core and a multi-phase winding wound around the stator core, wherein the stator core is provided with a plurality of stator slots along its circumference, each of the stator slots having M slot layers arranged along the radial direction of the stator core, wherein: M is greater than or equal to 4, and M is an even number; The winding of each phase includes N parallel branches, and each branch includes a first coil segment and a second coil segment connected to each other; the line segment of the first coil segment is wound around the stator core M / 2 times in a first direction, and the line segment of the second coil segment is wound around the stator core M / 2 times in a second direction, wherein N is less than or equal to M, and the first direction and the second direction are different; The first coil segment and the second coil segment each include Q winding portions and Q connecting segments, the Q winding portions are arranged along the circumferential direction of the stator core, and each connecting segment connects two adjacent winding portions, so that the winding portions and the connecting segments form a plurality of variable pitch units in a corresponding slot layer, wherein Q=M*P, P is the number of pole pairs of the motor; the slot layers corresponding to the two adjacent winding portions are one of the same layer, adjacent layers or separated layers; The multiple variable-pitch units include one or more of a short-pitch unit, a full-pitch unit, and a long-pitch unit, wherein the span of the short-pitch unit is smaller than the pole pitch of the motor, the span of the full-pitch unit is equal to the pole pitch of the motor, and the span of the long-pitch unit is larger than the pole pitch of the motor.

2. The stator assembly according to claim 1, wherein: The first coil segment and the second coil segment are connected via a connecting segment, and a winding direction of the connecting segment is the same as the first direction.

3. The stator assembly according to claim 1, wherein: The first direction and the second direction are opposite.

4. The stator assembly according to claim 2 or 3, wherein: The lead end of the first coil segment and the lead end of the second coil segment are located in the same slot layer.

5. The stator assembly according to claim 4, wherein: The lead end of the first coil segment and the lead end of the second coil segment are located in the innermost layer or the outermost layer in the slot layer.

6. The stator assembly according to claim 1, wherein: The span y1 of the short-pitch unit is τ-1 or τ-2, the span y1 of the long-pitch unit is τ+1 or τ+2, and the span y1 of the full-pitch unit is τ, wherein τ is the pole pitch of the motor.

7. The stator assembly according to claim 1, wherein: The number of stator slots is 54, the number of magnetic poles is 6, and the pole pitch is 9.

8. The stator assembly according to claim 1, wherein: The multi-phase winding is a three-phase symmetrical winding, the spatial phase difference between every two phases of the winding is 120°, and the conductor connection mode of the three-phase winding is star connection or delta connection.

9. An electric motor, comprising the stator assembly according to any one of claims 1 to 8 installed in the electric motor.

10. A vehicle, comprising the stator assembly according to any one of claims 1 to 8 installed in a motor of the vehicle or the motor according to claim 9 connected to a transmission system of the vehicle.

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