Hairpin type flat wire winding

Abstract

The invention relates to the field of new energy automobiles, and discloses a hairpin type flat wire winding, which is used for a motor with three slots per pole per phase, and comprises a three-phase winding, a flat wire conductor of the winding is circularly arranged on an annular stator by a circle according to a specific phase alternation and layer number distribution mode, and the three-phase winding is wound on the annular stator. The cable comprises eight layers of first phase conductors, six layers of first phase conductors and two layers of second phase conductors, two layers of first phase conductors and six layers of second phase conductors, eight layers of second phase conductors, six layers of second phase conductors and two layers of third phase conductors, two layers of second phase conductors and six layers of third phase conductors, eight layers of third phase conductors, six layers of third phase conductors and two layers of first phase conductors, and two layers of third phase conductors and six layers of first phase conductors. The arrangement mode of the flat wire conductors can significantly reduce magnetomotive force harmonic waves of the winding, so that the torque pulsation of the motor is small, the operation is more stable, and the NVH performance and the motor efficiency are improved.

Description

Technical Field

[0001] The present invention relates to the field of new energy vehicles, and in particular to a hairpin-type flat wire winding. Background Art

[0002] With the rapid development of new energy vehicle technology, electric vehicles (EVs), as representatives of green travel, are gradually becoming the mainstream trend of the future automotive market. As the "heart" of electric vehicles, the performance of the drive motor directly determines the power, economy and driving experience of the entire vehicle. Among the many types of motors, flat wire motors have gradually become the first choice for new energy vehicle drive systems due to their high slot fill rate, excellent heat dissipation performance and high power density.

[0003] Flat wire motors use Hairpin flat wire windings as their key components. This design not only optimizes the space utilization of the motor, but also improves the heat conduction efficiency, which helps the motor maintain stable performance under long-term high-load operation. However, the traditional Hairpin flat wire motor winding design, whether it is full-pitch winding or short-pitch winding, inevitably produces high magnetomotive force harmonics. These harmonics not only increase the electromagnetic load of the motor, but also lead to significant fluctuations in output torque, poor NVH noise performance, large harmonic magnetic field losses, and low motor efficiency. This affects the comfort of electric vehicle drivers and passengers and the vehicle's range. Summary of the invention

[0004] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art and to provide a hairpin-type flat wire winding, which can significantly reduce the magnetomotive force harmonics of the winding.

[0005] In order to achieve the above object, the present invention provides a hairpin type flat wire winding for a motor with 3 slots per pole per phase, comprising a three-phase winding, each phase winding comprising a plurality of parallel branches, each branch comprising a plurality of hairpin coils connected in series, the plurality of hairpin coils being wound in three-phase parallel manner on an annular stator having a plurality of stator slots, each stator slot being wound with 8 layers of flat wire conductors;

[0006] In adjacent stator slots, the arrangement of the flat wire conductors follows a specific phase alternation and layer number distribution pattern, specifically: 8 layers of first phase conductors, 6 layers of first phase conductors + 2 layers of second phase conductors, 2 layers of first phase conductors + 6 layers of second phase conductors, 8 layers of second phase conductors, 6 layers of second phase conductors + 2 layers of third phase conductors, 2 layers of second phase conductors + 6 layers of third phase conductors, 8 layers of third phase conductors, 6 layers of third phase conductors + 2 layers of first phase conductors, 2 layers of third phase conductors + 6 layers of first phase conductors;

[0007] The arrangement is cyclically arranged on the annular stator.

[0008] In some embodiments, the number of stator slots is 36, 54 or 72.

[0009] In some embodiments, the three-phase winding is a U-phase winding, a V-phase winding and a W-phase winding, and the U-phase winding, the V-phase winding and the W-phase winding respectively include two parallel branches;

[0010] Starting from the initial inflow point of the current, every nine hairpin coils are connected in series on the annular stator to form a current loop, and each branch of each phase has four current loops;

[0011] When n∈[1,4], the hairpin coil of the nth current loop of the first branch is located at the 2n-1 layer and the 2n layer, the current on the nth current loop flows into the 2n-1 layer and flows out of the 2n layer, and the hairpin coil is wound along the first direction; the hairpin coil of the nth current loop of the second branch is located at the 2(5-n) and 2(5-n)-1 layers, the current of the nth current loop flows into the 2(5-n) layer and flows out of the 2(5-n)-1 layer, and its hairpin coil is wound along the second direction opposite to the first direction; the final outflow point of the current of the first branch and the final outflow point of the current of the second branch are located at the 8th layer and the 1st layer of the same slot;

[0012] Among them, in the U-phase winding, the spans of the nine hairpin coils of the first current loop of the first branch are 9, 9, 7, 9, 9, 10, 9, 9, 10 stator slots in sequence; the spans of the nine hairpin coils of the second and third current loops of the first branch are 9, 9, 10, 9, 9, 7, 9, 9, 10 stator slots in sequence; the spans of the nine hairpin coils of the fourth current loop of the first branch are 9, 9, 10, 9, 9, 10, 9, 9, 7 stator slots in sequence;

[0013] The spans of the nine hairpin coils of the first current loop of the second branch are 7, 9, 9, 10, 9, 9, 10, 9, 9 stator slots, respectively; the spans of the nine hairpin coils of the second and third current loops of the second branch are 10, 9, 9, 7, 9, 9, 10, 9, 9 stator slots, respectively; the spans of the nine hairpin coils of the fourth current loop of the second branch are 10, 9, 9, 10, 9, 9, 7, 9, 9 stator slots, respectively;

[0014] The V-phase winding is formed by shifting the U-phase winding by 6 slot pitches in the direction of increasing slot position;

[0015] The W-phase winding is formed by shifting the U-phase winding by 6 slot pitches in the direction of decreasing slot position.

[0016] In some embodiments, the stator slots are expanded circumferentially along a first direction and numbered in the order of 1-54, and the number of layers is numbered according to ah along the direction from the bottom of the stator slot to the slot mouth, and xy is defined as the yth layer of the xth stator slot, x∈[1,54], y∈[a,h], the 1st to the 8th layers correspond to the h to the a layers respectively, U1+ is the initial inflow point of the first branch current on the U phase, U1- is the final outflow point of the first branch current on the U phase, and the winding connection line from U1+ to U1- of the first branch of the U phase is:

[0017] 19h→10g→1h→46g→37h→30g→21h→12g→3h→48g→39h→29g→20h→11g→2h→47g→38h→28g→19f→10e→1f→46e→37f→27e→18f→9e→54f→45e→36f→29e→20f→11e→2f→47e→38f→28e→ 19d→10c→1d→46c→37d→27c→18d→9c→54d→45c→36d→29c→20d→11c→2d→47c→38d→28c→19b→10a→1b→46a→37b→27a→18b→9a→54b→45a→36b→26a→17b→8a→53b→44a→35b→28a;

[0018] U2+ is the initial inflow point of the second branch current on the U phase, U2- is the final outflow point of the second branch current on the U phase, and the winding connection line from U2+ to U2- of the second branch of the U phase is:

[0019] 37a→44b→53a→8b→17a→26b→35a→45b→54a→9b→18a→27b→36a→46b→1a→10b→19a→28b→37c→47d→2c→11d→20c→29d→38c→45d→54c→9d→18c→27d→36c→46d→1c→10d→19c→28d→ 37e→47f→2e→11f→20e→29f→38e→45f→54e→9f→18e→27f→36e→46f→1e→10f→19e→28f→37g→47h→2g→11h→20g→29h→38g→48h→3g→12h→21g→30h→39g→46h→1g→10h→19g→28h.

[0020] In some embodiments, the three phases are a U-phase winding, a V-phase winding and a W-phase winding, and the U-phase winding, the V-phase winding and the W-phase winding respectively include three parallel branches;

[0021] Starting from the current inflow point, the flat wire cooperates with the hairpin coil to go around along the circumferential direction of the annular stator to the next layer, and every two layers form a current loop, and each branch of each phase has 8 current loops;

[0022] When n∈[1,4], the nth current loop of the first branch is located at the 2(5-n) and 2(5-n)-1 layers, the current on the nth current loop flows into the 2(5-n) layer and flows out of the 2(5-n)-1 layer, and the hairpin coil is wound along the first direction; when n∈[5,8], the hairpin coil of the nth current loop of the first branch is located at the 2(n-4)-1 and 2(n-4) layers, the current of the nth current loop flows into the 2(n-4)-1 layer and flows out of the 2(n-4) layer, and its hairpin coil is wound along the second direction opposite to the first direction;

[0023] Wherein, in the U-phase winding, the second branch is translated by 18 slot pitches along the direction of increasing slot position from the first branch, and the third branch is translated by 18 slot pitches along the direction of decreasing slot position from the first branch, and the span of the hairpin coil of each current loop of the first branch, the second branch and the third branch is 8 stator slots;

[0024] The V-phase winding is formed by shifting the U-phase winding by 6 slot pitches in the direction of increasing slot position;

[0025] The W-phase winding is formed by shifting the U-phase winding by 6 slot pitches in the direction of decreasing slot position.

[0026] In some embodiments, the stator slots are expanded circumferentially along a first direction and numbered in the order of 1-54, and the number of layers is numbered according to ah along the direction from the bottom of the stator slot to the slot mouth, and xy is defined as the yth layer of the xth stator slot, x∈[1,54], y∈[a,h], the 1st to the 8th layers correspond to the h to the a layers respectively, U1+ is the initial inflow point of the first branch current on the U phase, U1- is the final outflow point of the first branch current on the U phase, and the winding connection line from U1+ to U1- of the first branch of the U phase is:

[0027] 26a→17b→9a→54b→46a→37b→27c→18d→10c→1d→47c→38d→27e→18f→10e→1f→47e→38f→28g→19h→11g→2h→48g→39h→48h→3g→11h→20g→28h→37g→47f→2e→10f→19e→27f→36e→47d→2c→10d→19c→27d→36c→46b→1a→9b→18a→26b→35a; U2+ and U3+ are 44a and 8a respectively.

[0028] In some embodiments, the inlet and outlet ends of the hairpin-type flat wire winding of the two-branch connection mode are located at the welding end of the flat wire winding.

[0029] In some embodiments, the inlet and outlet ends of the hairpin-type flat wire winding with three-branch connection are located at the crown end of the flat wire winding.

[0030] In some embodiments, the span of the welding ends of the hairpin-type flat wire winding is 9.

[0031] Through the above technical scheme, the flat wire conductor follows a specific phase alternation and layer distribution pattern and is circulated on the annular stator for one cycle, specifically: 8 layers of first phase conductors, 6 layers of first phase conductors + 2 layers of second phase conductors, 2 layers of first phase conductors + 6 layers of second phase conductors, 8 layers of second phase conductors, 6 layers of second phase conductors + 2 layers of third phase conductors, 2 layers of second phase conductors + 6 layers of third phase conductors, 8 layers of third phase conductors, 6 layers of third phase conductors + 2 layers of first phase conductors, 2 layers of third phase conductors + 6 layers of first phase conductors. This arrangement of flat wire conductors can significantly reduce the magnetomotive force harmonics of the winding, thereby reducing the torque pulsation of the motor, running more smoothly, and improving the NVH performance and motor efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a schematic diagram of the distribution of three-phase conductors in the slots of a hairpin-type flat wire winding provided by the present invention;

[0033] Figure 2 It is a schematic diagram of the distribution of three-phase conductors in the slots of a conventional winding 1 (full-pitch flat wire winding);

[0034] Figure 3 It is a schematic diagram of the distribution of three-phase conductors in the slot of a conventional winding 2 (same-slot, different-phase, centralized, short-distance flat wire winding);

[0035] Figure 4 It is a schematic diagram of the distribution of three-phase conductors in the slot of a conventional winding 3 (same-slot, different-phase, cross-type, short-distance flat wire winding);

[0036] Figure 5 This is a schematic diagram of the expansion of the first branch winding of the U phase in the branch connection mode of the second embodiment provided by the present invention;

[0037] Figure 6 This is a schematic diagram of the expansion of the U-phase winding of a branch connection mode of a second embodiment provided by the present invention;

[0038] Figure 7 This is a schematic diagram of a three-phase winding expansion of a branch connection method in a second embodiment provided by the present invention;

[0039] Figure 8 This is a schematic diagram of the expansion of the first branch winding of the U phase in the third branch connection mode of an embodiment provided by the present invention;

[0040] Fig. 9This is a schematic diagram of the expansion of the U-phase winding in a branch connection mode of a third embodiment provided by the present invention;

[0041] Fig.10 This is a schematic diagram of a three-phase winding expansion of a third branch connection method provided in an embodiment of the present invention;

[0042] Fig.11 It is a schematic diagram of the conductor distribution in a single stator slot in the present invention. DETAILED DESCRIPTION

[0043] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0044] For ease of understanding, the terms mentioned in the present invention are explained below.

[0045] The stator slots are located on the inner surface of the stator core, and refer to the grooves on the stator core of the motor. These grooves are usually arranged in parallel and are used to accommodate and fix the electrical windings (i.e. coils). Each stator slot has a slot bottom and a slot opening, wherein the slot bottom is close to the outer surface of the stator, and the slot opening is close to the central axis of the stator.

[0046] The pitch refers to the number of slots between two adjacent effective sides of a coil. The pitch is also called the span. The value of the pitch is expressed in the number of slots. It should be noted that the effective side specifically refers to the part of the winding located in the stator slot, which can cut the magnetic field and induce electromotive force in the stator slot. For example, if one effective side of a coil is located in slot 1 and the other effective side is located in slot 9, then the pitch of the coil is 8 slots.

[0047] The pole pitch refers to the distance spanned by a pole on the stator circumference, which is measured in the number of slots. Pole pitch = number of stator slots / number of poles. Slot fill factor refers to the degree of filling of the winding copper wire in the motor slot, which is usually expressed as the percentage of the copper wire cross-sectional area to the slot cross-sectional area.

[0048] like Figure 1 As shown, the flat wire conductors in the embodiment of the present invention are distributed differently in the stator slots. Figure 2 , Figure 3 as well as Figure 4 The traditional full-pitch flat wire winding, the same-slot different-phase concentrated short-pitch flat wire winding, and the same-slot different-phase crossed short-pitch flat wire winding shown in the figure.

[0049] The hairpin-type flat wire winding provided by the present invention is used for a motor with a slot number Q=3 per pole per phase, comprising a three-phase winding, each phase winding comprising a plurality of parallel branches, each branch comprising a plurality of hairpin coils connected in series, the plurality of hairpin coils being wound on a ring-shaped stator having a plurality of slots in a three-phase parallel manner, and each stator slot being wound with 8 layers of flat wire conductors;

[0050] In adjacent stator slots, the arrangement of the flat wire conductors follows a specific phase alternation and layer distribution pattern and is circulated on the annular stator, specifically: 8 layers of first phase conductors, 6 layers of first phase conductors + 2 layers of second phase conductors, 2 layers of first phase conductors + 6 layers of second phase conductors, 8 layers of second phase conductors, 6 layers of second phase conductors + 2 layers of third phase conductors, 2 layers of second phase conductors + 6 layers of third phase conductors, 8 layers of third phase conductors, 6 layers of third phase conductors + 2 layers of first phase conductors, 2 layers of third phase conductors + 6 layers of first phase conductors. This distribution of flat wire conductors can significantly reduce the magnetomotive force harmonics of the winding, thereby reducing the torque pulsation of the motor, running more smoothly, and improving NVH performance and motor efficiency.

[0051] The hairpin flat wire winding of the present invention can be used for a motor with 4 poles and 36 slots, 6 poles and 54 slots, or 8 poles and 72 slots.

[0052] The hairpin coil in the present invention comprises two parallel straight line segments (two effective sides of the hairpin coil) and a connecting segment connecting the two straight line segments, the straight line segments are inserted into the stator slots, and the connecting segment is arranged outside the stator slots. The pitch of the hairpin coil is the number of stator slots spanned by the two parallel straight line segments of the hairpin coil. The pitch (span) of the welding end of the present invention is the number of stator slots spanned by the adjacent straight line segments of two adjacent hairpin coils.

[0053] It should also be noted that Figure 1 In the figure, “+” represents the current flowing into the conductor, “-” represents the current flowing out of the conductor, and U, V, and W represent the flat wire conductors of different phases in the stator slots.

[0054] By placing the winding ( Figure 1 ) and traditional winding 1( Figure 2 ), conventional winding 2( Figure 3 ), conventional winding 3( Figure 4 ) structural parameters are used to establish a three-dimensional model of the motor in the simulation software. The specific values ​​of the magnetomotive force harmonics of different windings are calculated through the numerical calculation method built into the simulation software. The simulation values ​​of the magnetomotive force harmonics of different windings are compared to obtain the following table:

[0055] Table 1 Magnetomotive force harmonic values ​​of conventional windings and windings of the present invention

[0056]

[0057]

[0058] From the data in Table 1, it can be seen that the flat wire winding of the present invention has a significant effect on weakening the 5th, 7th, 9th, 11th, 13th and 15th harmonics of the winding magnetomotive force compared with the other three groups of traditional windings.

[0059] The solution provided by the embodiment of the present invention is described in detail below through specific examples.

[0060] Embodiment 1

[0061] The embodiment of the present invention provides a 6-pole 54-slot hairpin flat wire winding. The number of poles of the hairpin flat wire winding in the present invention is 6, the number of slots of each pole and each phase flat wire winding is 3, and the number of stator slots of each phase branch winding is 18. Therefore, the total number of stator slots of the three-phase flat wire wave winding is 54. According to the calculation method of the pole pitch, the pole pitch is 54 / 6=9.

[0062] In the present invention, the number of conductor layers in each stator slot is 8, that is, each stator slot has an 8-layer structure, the layer close to the slot opening is the first layer, and the layer close to the slot bottom is the eighth layer.

[0063] For the convenience of description, the stator slots are expanded along the circumferential direction along the first direction and numbered in the order of 1-54, and the layers are numbered in the direction from the bottom of the stator slot to the slot opening according to ah, such as Fig.11 As shown, xy is defined as the yth layer of the xth stator slot, x∈[1,54], y∈[a,h], and the 1st to 8th layers correspond to the h to a layers respectively.

[0064] In the present invention, the three phases are U phase, V phase and W phase.

[0065] In the embodiment of the present invention, Figure 1 As shown, the position of the flat wire conductor in the adjacent stator slots is shown in Table 2 below (1-54 in Table 2 represents the slot number of the stator slot, ah represents the layer number of the conductor, "+" in Table 2 represents the current flowing into the conductor, and "-" represents the current flowing out of the conductor):

[0066]

[0067]

[0068] According to the arrangement of Table 2, further, when each phase winding has two branches, such as Figure 6 As shown, the U-phase winding includes two branches, namely the U-phase first branch (i.e. Figure 6 U1 in the U phase), the second branch of the U phase (i.e. Figure 6 2).

[0069] like Figure 7 As shown, the V-phase winding includes two branches, namely the first branch of the V-phase (i.e. Figure 7 V1 in the V phase), the second branch of the V phase (i.e. Figure 7 V2 in the W phase winding); the W phase winding includes two branches, namely the W phase first branch (i.e. Figure 7 W1 in the W phase), the second branch of the W phase (i.e. Figure 7 W2 in ).

[0070] Starting from the initial inflow point of the current, every nine hairpin coils are connected in series on the stator to form a current loop. Each branch of each phase has four current loops. The hairpin coils of each current loop are arranged across layers. Each hairpin coil has a crown end and two welding ends. The crown end and the welding end are respectively located on both sides of the stator. The two welding ends of each hairpin coil extend to the left and right sides respectively. At this time, the incoming and outgoing ends of the flat wire winding are located at the welding ends of the flat wire winding.

[0071] Specifically, when n∈[1,4], the hairpin coil of the nth current loop of the first branch is located at the 2n-1 layer and the 2n layer, the current on the nth current loop flows into the 2n-1 layer and flows out of the 2n layer, and the hairpin coil is along the first direction ( Figure 6 from right to left in the middle).

[0072] When n∈[1,4], the hairpin coil of the nth current loop of the second branch is located at the 2nd (5-n) and 2nd (5-n)-1 layers, and the current of the nth current loop flows into the 2nd (5-n) layer and flows out of the 2nd (5-n)-1 layer, and its hairpin coil flows in a second direction opposite to the first direction ( Figure 6 from left to right in the middle).

[0073] The final outflow point of the current of the first branch and the final outflow point of the current of the second branch are located at the 8th layer and the 1st layer of the same slot.

[0074] Current loop is a term defined in this application to describe the cross-layer connection method of the hairpin coil.

[0075] That is, the hairpin coil of the first current loop of the first branch flows in from the first layer (h layer) and flows out from the second layer (g layer), the hairpin coil of the second current loop flows in from the third layer (f layer) and flows out from the fourth layer (e layer), the hairpin coil of the third current loop flows in from the fifth layer (d layer) and flows out from the sixth layer (c layer), and the hairpin coil of the fourth current loop flows in from the seventh layer (b layer) and flows out from the eighth layer (a layer).

[0076] The hairpin coil of the first current loop of the second branch flows in from the eighth layer (layer a) and flows out from the seventh layer (layer b), the hairpin coil of the second current loop flows in from the sixth layer (layer c) and flows out from the fifth layer (layer d), the hairpin coil of the third current loop flows in from the fourth layer (layer e) and flows out from the third layer (layer f), and the hairpin coil of the fourth current loop flows in from the second layer (layer g) and flows out from the first layer (layer h).

[0077] The specific winding method is that, in the U-phase winding, the spans of the nine hairpin coils of each current loop on the first branch are 9, 9, 7, 9, 9, 10, 9, 9, 10 stator slots in sequence; the spans of the nine hairpin coils of the second and third current loops of the first branch are 9, 9, 10, 9, 9, 7, 9, 9, 10 stator slots in sequence; the spans of the nine hairpin coils of the fourth current loop of the first branch are 9, 9, 10, 9, 9, 10, 9, 9, 7 stator slots in sequence;

[0078] The spans of the nine hairpin coils of the first current loop of the second branch are 7, 9, 9, 10, 9, 9, 10, 9, 9 stator slots, respectively; the spans of the nine hairpin coils of the second and third current loops of the second branch are 10, 9, 9, 7, 9, 9, 10, 9, 9 stator slots, respectively; the spans of the nine hairpin coils of the fourth current loop of the second branch are 10, 9, 9, 10, 9, 9, 7, 9, 9 stator slots, respectively;

[0079] The V-phase winding is formed by shifting the U-phase winding by 6 slot pitches in the direction of increasing slot position;

[0080] The W-phase winding is formed by shifting the U-phase winding by 6 slot pitches in the direction of decreasing slot position.

[0081] Specifically, Figure 6 As shown, U1+ is the initial inflow point of the first branch current on the U phase, U1- is the final outflow point of the first branch current on the U phase, U2+ is the initial inflow point of the second branch current on the U phase, and U2- is the final outflow point of the second branch current on the U phase.

[0082] When U1+ is 19h, the connection line from U1+ to U1- of the first branch of phase U is:

[0083] 19h→10g→1h→46g→37h→30g→21h→12g→3h→48g→39h→29g→20h→11g→2h→47g→38h→28g→19f→10e→1f→46e→37f→27e→18f→9e→54f→45e→36f→29e→20f→11e→2f→47e→38f→28e→ 19d→10c→1d→46c→37d→27c→18d→9c→54d→45c→36d→29c→20d→11c→2d→47c→38d→28c→19b→10a→1b→46a→37b→27a→18b→9a→54b→45a→36b→26a→17b→8a→53b→44a→35b→28a.

[0084] The U2 branch is located at the position of the U1 branch which is shifted by 9 slots in the direction of increasing slots. When U2+ is 37a, the connection line from the second branch of the U phase, U2+ to U2-, is:

[0085] 37a→44b→53a→8b→17a→26b→35a→45b→54a→9b→18a→27b→36a→46b→1a→10b→19a→28b→37c→47d→2c→11d→20c→29d→38c→45d→54c→9d→18c→27d→36c→46d→1c→10d→19c→28d→ 37e→47f→2e→11f→20e→29f→38e→45f→54e→9f→18e→27f→36e→46f→1e→10f→19e→28f→37g→47h→2g→11h→20g→29h→38g→48h→3g→12h→21g→30h→39g→46h→1g→10h→19g→28h.

[0086] That is, one effective side of the first hairpin coil of the first branch is located at the h layer of slot No. 19, and the other effective side is located at the g layer of slot No. 10, that is, the current flows into the h layer of slot No. 19 and flows out from the g layer of slot No. 10, with a span of 9 slots. The left end of the first hairpin coil and the right end of the second hairpin coil are twisted and welded together, and the welding pitch between the first hairpin coil and the second hairpin coil is 9 slots.

[0087] Similarly, one effective side of the second hairpin coil of the first branch is located at the h layer of slot No. 1, and the other effective side is located at the g layer of slot No. 46, that is, the current flows into the h layer of slot No. 1 and flows out from the g layer of slot No. 46, with a span of 9 slots. The left end of the second hairpin coil and the right end of the third hairpin coil are twisted and welded together, and the welding pitch between the second hairpin coil and the third hairpin coil is 9 slots.

[0088] By analogy, the first hairpin coil to the ninth hairpin coil are connected in series to form the first current loop, which is located in the h and g layers. The tenth hairpin coil to the eighteenth hairpin coil are connected in series to form the second current loop, which is located in the f and e layers. The nineteenth hairpin coil to the twenty-seventh hairpin coil are connected in series to form the third current loop, which is located in the d and c layers. The twenty-eighth hairpin coil to the thirty-sixth hairpin coil are connected in series to form the fourth current loop, which is located in the b and a layers. The first The current loops to the fourth current loop are connected in sequence, that is, the left end of the previous hairpin coil and the right end of the next hairpin coil are welded, wherein the current flows out from the left end of the ninth hairpin coil (the g layer of slot No. 28), and then flows to the right end of the tenth hairpin coil (the f layer of slot No. 19); after flowing out from the left end of the eighteenth hairpin coil (the e layer of slot No. 28), it flows to the right end of the nineteenth hairpin coil (the d layer of slot No. 19); after flowing out from the left end of the twenty-seventh hairpin coil (the c layer of slot No. 28), it flows to the right end of the twenty-eighth hairpin coil (the b layer of slot No. 19).

[0089] One effective side of the first hairpin coil of the second branch is located at the a layer of slot No. 37, and the other effective side is located at the b layer of slot No. 44, that is, the current flows into the a layer of slot No. 37 and flows out from the b layer of slot No. 44, with a span of 7 slots. The right end of the first hairpin coil and the left end of the second hairpin coil are twisted and welded together, and the welding pitch between the first hairpin coil and the second hairpin coil is 9 slots.

[0090] Similarly, one effective side of the second hairpin coil of the second branch is located at the a layer of slot 53, and the other effective side is located at the b layer of slot 8, that is, the current flows into the a layer of slot 53 and flows out from the b layer of slot 8, with a span of 9 slots. The right end of the second hairpin coil and the left end of the third hairpin coil are twisted and welded together, and the welding pitch between the second hairpin coil and the third hairpin coil is 9 slots.

[0091] By analogy, the first to ninth hairpin coils of the second branch are connected in series in sequence to form the first current loop, which is located at layers a and b. The tenth to eighteenth hairpin coils are connected in series in sequence to form the second current loop, which is located at layers c and d. The nineteenth to twenty-seventh hairpin coils are connected in series in sequence to form the third current loop, which is located at layers e and f. The twenty-eighth to thirty-sixth hairpin coils are connected in series in sequence to form the fourth current loop, which is located at layers g and h. The first current loop to the fourth current loop are connected in sequence, that is, the right end of the previous hairpin coil and the left end of the next hairpin coil are welded, wherein the current flows out from the right end of the ninth hairpin coil (the b layer of slot No. 28), and then flows to the left end of the tenth hairpin coil (the c layer of slot No. 37); after flowing out from the right end of the eighteenth hairpin coil (the d layer of slot No. 28), it flows to the left end of the nineteenth hairpin coil (the e layer of slot No. 37); after flowing out from the right end of the twenty-seventh hairpin coil (the f layer of slot No. 28), it flows to the left end of the twenty-eighth hairpin coil (the g layer of slot No. 37).

[0092] The current flow direction from the first current loop to the fourth current loop of the first branch on the U phase is h, g layer →f, e layer →d, c layer →b, a layer, and the right end of the previous hairpin and the left end of the next hairpin are welded.

[0093] The current flow direction from the first current loop to the fourth current loop of the second branch on the U phase is a, b layer →c, d layer →e, f layer →g, h layer; the left end of the previous hairpin and the right end of the next hairpin are welded.

[0094] According to the above description, the winding of the first branch and the second branch of the U phase can be realized. Since the winding method of the V phase winding is to shift the U phase winding by 6 slot pitches along the increasing direction of the slot position, that is, the first branch of the V phase flows into the hth layer of slot No. 25 and finally flows out from the ath layer of slot No. 34, and the second branch flows into the ath layer of slot No. 43 and finally flows out from the hth layer of slot No. 34, the detailed connection route will not be repeated.

[0095] Since the winding method of the W-phase winding is to shift the U-phase winding by 6 slot pitches along the direction of decreasing slot position, that is, the first branch of the V-phase flows in from the h-th layer of slot No. 13 and finally flows out from the a-th layer of slot No. 22, and the second branch flows in from the a-th layer of slot No. 31 and finally flows out from the h-th layer of slot No. 22, the detailed connection route will not be repeated here.

[0096] This completes the winding of the entire 6-pole 54-slot hairpin flat wire winding when each phase winding has 2 branches (such as Figure 7 shown).

[0097] like Fig. 9As shown, when each phase winding has three branches, the U-phase winding includes three branches, namely the U-phase first branch (i.e. Fig. 9 U1 in the U phase), the second branch of the U phase (i.e. Fig. 9 U2 in the U phase), the third branch of the U phase (i.e. Fig. 9 in U3).

[0098] like Fig.10 As shown, the V-phase winding includes three branches, namely the first branch of the V-phase (i.e. Fig.10 V1 in the V phase), the second branch of the V phase (i.e. Fig.10 V2 in the V phase), the third branch of the V phase (i.e. Fig.10 V3 in the figure); the W-phase winding includes three branches, namely the first branch of the W-phase (i.e. Fig.10 W1 in the W phase), the second branch of the W phase (i.e. Fig.10 W2 in the W phase), the third branch of the W phase (i.e. Fig.10 in W3).

[0099] Starting from the current inflow point, the flat wire cooperates with the hairpin coil to go around along the circumferential direction of the annular stator to the next layer, and every two layers form a current loop, and each branch of each phase has 8 current loops;

[0100] When n∈[1,4], the nth current loop of the first branch is located at the 2(5-n) and 2(5-n)-1 layers, the current on the nth current loop flows into the 2(5-n) layer and flows out of the 2(5-n)-1 layer, and the hairpin coil is wound along the first direction; when n∈[5,8], the hairpin coil of the nth current loop of the first branch is located at the 2(n-4)-1 and 2(n-4) layers, the current of the nth current loop flows into the 2(n-4)-1 layer and flows out of the 2(n-4) layer, and its hairpin coil is wound along the second direction opposite to the first direction;

[0101] Wherein, in the U-phase winding, the second branch is translated by 18 slot pitches along the direction of increasing slot position from the first branch, and the third branch is translated by 18 slot pitches along the direction of decreasing slot position from the first branch, and the span of the hairpin coil on each current loop of the first branch, the second branch and the third branch is 8 stator slots;

[0102] Starting from the initial inflow point of the current, the flat wire cooperates with the hairpin coil to go around along the circumferential direction of the annular stator to the next layer, and every two layers constitute a current loop. Each branch of each phase has 8 current loops. The hairpin coils of each current loop are arranged across layers, and each hairpin coil has a crown end and two welding ends. The crown end and the welding end are respectively located on both sides of the stator. The two welding ends of each hairpin coil extend to the left and right sides respectively. At this time, the incoming and outgoing ends of the flat wire winding are located at the crown end of the flat wire winding.

[0103] When n∈[1,4], the hairpin coil of the nth current loop of the first branch is located at the 2nd (5-n) and 2nd (5-n)-1 layers, the current on the nth current loop flows into the 2nd (5-n) layer and flows out of the 2nd (5-n)-1 layer, and the hairpin coil is along the first direction ( Figure 8 When n∈[5,8], the hairpin coil of the nth current loop of the first branch is located at the 2(n-4)-1 and 2(n-4) layers, and the current of the nth current loop flows into the 2(n-4)-1 layer and flows out of the 2(n-4) layer. The hairpin coil is wound in a second direction opposite to the first direction ( Figure 8 from left to right in the middle).

[0104] That is, the current of the first current loop of the first branch flows into the eighth layer (layer a) and flows out of the seventh layer (layer b); the current of the second current loop flows into the sixth layer (layer c) and flows out of the fifth layer (layer d); the current of the third current loop flows into the fourth layer (layer e) and flows out of the third layer (layer f); the current of the fourth current loop flows into the second layer (layer g) and flows out of the first layer (layer h); the current of the fifth current loop flows into the first layer (layer h) and flows out of the second layer (layer g); the current of the sixth current loop flows into the third layer (layer f) and flows out of the fourth layer (layer e); the current of the seventh current loop flows into the fifth layer (layer d) and flows out of the sixth layer (layer c); the current of the eighth current loop flows into the seventh layer (layer b) and flows out of the eighth layer (layer a).

[0105] The specific winding method is that in the U-phase winding, the span of the hairpin coil of each current loop on the first branch is 8 stator slots;

[0106] The V-phase winding is formed by shifting the U-phase winding by 6 slot pitches in the direction of increasing slot position;

[0107] The W-phase winding is formed by shifting the U-phase winding by 6 slot pitches in the direction of decreasing slot position.

[0108] Specifically, combined Fig. 9 As shown, U1+ is the initial inflow point of the first branch current on the U phase, U1- is the final outflow point of the first branch current on the U phase, U2+ is the initial inflow point of the second branch current on the U phase, U2- is the final outflow point of the second branch current on the U phase, U3+ is the initial inflow point of the third branch current on the U phase, and U3- is the final outflow point of the third branch current on the U phase.

[0109] When U1+ is 26a, the connection line from U1+ to U1- of the first branch of phase U is:

[0110] 26a→17b→9a→54b→46a→37b→27c→18d→10c→1d→47c→38d→27e→18f→10e→1f→47e→38f→28g→19h→11g→2h→48g→39h→48h→3g→11h→20g→28h→37g→47f→2e→10f→19e→27f→36e→47d→2c→10d→19c→27d→36c→46b→1a→9b→18a→26b→35a.

[0111] That is, one effective side of the first hairpin coil of the first branch is located at the b layer of slot No. 17, and the other effective side is located at the a layer of slot No. 9, that is, the current flows into the b layer of slot No. 17 and flows out from the a layer of slot No. 9, with a span of 8 slots. The left end of the first hairpin coil and the right end of the second hairpin coil are twisted and welded together, and the welding pitch between the first hairpin coil and the second hairpin coil is 9 slots.

[0112] Similarly, one effective side of the second hairpin coil of the first branch is located at the b layer of slot No. 54, and the other effective side is located at the a layer of slot No. 46, that is, the current flows into the b layer of slot No. 54 and flows out from the a layer of slot No. 46, with a span of 8 slots. The left end of the second hairpin coil and the right end of the third hairpin coil are twisted and welded together, and the welding pitch between the second hairpin coil and the third hairpin coil is 9 slots.

[0113] One effective side of the third hairpin coil of the first branch is located at the b layer of slot No. 37, and the other effective side is located at the c layer of slot No. 27, that is, the current flows into the b layer of slot No. 37 and flows out from the c layer of slot No. 27, with a span of 10 slots. The left end of the third hairpin coil and the right end of the fourth hairpin coil are twisted and welded together, and the welding pitch between the third hairpin coil and the fourth hairpin coil is 9 slots.

[0114] By analogy, hairpin coils of different spans are connected in series from the current inflow point (+) to the current outflow point (-), and the first current loop to the eighth current loop are located on a, b layers, c, d layers, e, f layers, g, h layers, h, g layers, f, e layers, d, c layers, b, a layers respectively. The first current loop to the eighth current loop are connected in sequence, among which the third, sixth, ninth, twelfth, fifteenth, eighteenth, and twenty-first hairpin coils are located on two adjacent current loops, and their spans are 10, 11, 10, 9, 10, 11, and 10 respectively. Except for the third, sixth, ninth, twelfth, fifteenth, eighteenth, and twenty-first hairpin coils, the spans of the hairpin coils are all 8.

[0115] The current flow direction from the first current loop to the fourth current loop of the first branch on the U phase is a, b layer →c, d layer →e, f layer →g, h layer, and the left end of the previous hairpin and the right end of the next hairpin are welded.

[0116] The current flow direction from the fifth current loop to the eighth current loop of the first branch on the U phase is h, g layer →f, e layer →d, c layer →b, a layer; the right end of the previous hairpin and the left end of the next hairpin are welded.

[0117] According to the above description, the winding of the first branch of the U phase can be realized. For the winding of the other two branches of the U phase, first, according to the current inflow point U2+ of the second branch of the U phase being 44a, and the second branch and each hairpin coil on the first branch having the same span in sequence, the winding connection line of the second branch of the U phase flowing in from 44a and finally flowing out from 53a can be obtained; according to the current inflow point U2+ of the third branch of the U phase being 8a, and the third branch and each hairpin coil on the first branch having the same span in sequence, the winding connection line of the third branch of the U phase flowing in from 8a and finally flowing out from 17a can be obtained; Fig. 9 As shown, the winding principles of the second branch of the U phase and the third branch of the U phase are the same as those of the first branch of the U phase, and will not be repeated here.

[0118] Since the winding method of the V-phase winding is to shift the U-phase winding by 6 slot pitches along the increasing direction of the slot position, that is, the first branch of the V-phase flows in from the a-th layer of slot No. 32, and finally flows out from the a-th layer of slot No. 41, the second branch flows in from the a-th layer of slot No. 50, and finally flows out from the a-th layer of slot No. 5, the third branch flows in from the a-th layer of slot No. 14, and finally flows out from the a-th layer of slot No. 23, the detailed connection routes are not repeated here.

[0119] Since the winding method of the W-phase winding is to shift the U-phase winding by 6 slot pitches along the direction of decreasing slot position, that is, the first branch of the W-phase flows in from the a-th layer of slot No. 20, and finally flows out from the a-th layer of slot No. 29, the second branch flows in from the a-th layer of slot No. 38, and finally flows out from the a-th layer of slot No. 47, the third branch flows in from the a-th layer of slot No. 2, and finally flows out from the a-th layer of slot No. 11, the detailed connection routes will not be repeated here.

[0120] At this point, the winding of the entire 6-pole 54-slot hairpin flat wire winding is completed when each phase winding has 3 branches.

[0121] It can be understood that since the stator slots are arranged in a ring shape, the slot position where the current outflow point is located specified in this embodiment has different slot number marks under different expansion methods. According to the winding method given in the embodiment of the present invention, those skilled in the art may obtain different winding connection line combinations by connecting current from different slot numbers. Therefore, what is actually disclosed in the present invention is the arrangement of flat wire conductors of different phases in the stator slots. According to the distribution of the flat wire conductors, the winding connection lines that start to be wound when the current flows into the a or h layer of any stator slot are all within the protection scope of the present invention for obtaining different winding lines by simply changing the current inflow point of the stator slot.

Claims

1. A hairpin flat wire winding for a motor having 3 slots per pole per phase, characterized in that: The hairpin-type flat wire winding includes a three-phase winding, each phase winding includes a plurality of parallel branches, each branch includes a plurality of hairpin coils connected in series, and the plurality of hairpin coils are wound in three-phase parallel manner on an annular stator having a plurality of stator slots, and each stator slot is wound with 8 layers of flat wire conductors; In adjacent stator slots, the arrangement of the flat wire conductors follows a specific phase alternation and layer number distribution pattern, specifically: 8 layers of first phase conductors, 6 layers of first phase conductors + 2 layers of second phase conductors, 2 layers of first phase conductors + 6 layers of second phase conductors, 8 layers of second phase conductors, 6 layers of second phase conductors + 2 layers of third phase conductors, 2 layers of second phase conductors + 6 layers of third phase conductors, 8 layers of third phase conductors, 6 layers of third phase conductors + 2 layers of first phase conductors, 2 layers of third phase conductors + 6 layers of first phase conductors; The arrangement is cyclically arranged on the annular stator.

2. The hairpin flat wire winding according to claim 1, characterized in that: The number of the stator slots is 36, 54 or 72.

3. The hairpin flat wire winding according to claim 2, characterized in that: The three-phase windings are U-phase windings, V-phase windings and W-phase windings, and the U-phase windings, V-phase windings and W-phase windings respectively include two parallel branches; Starting from the initial inflow point of the current, every nine hairpin coils are connected in series on the annular stator to form a current loop, and each branch of each phase has four current loops; When n∈[1,4], the hairpin coil of the nth current loop of the first branch is located at the 2n-1 layer and the 2n layer, the current on the nth current loop flows into the 2n-1 layer and flows out of the 2n layer, and the hairpin coil is wound along the first direction; the hairpin coil of the nth current loop of the second branch is located at the 2(5-n) and 2(5-n)-1 layers, the current of the nth current loop flows into the 2(5-n) layer and flows out of the 2(5-n)-1 layer, and its hairpin coil is wound along the second direction opposite to the first direction; the final outflow point of the current of the first branch and the final outflow point of the current of the second branch are located at the 8th layer and the 1st layer of the same slot; Wherein, in the U-phase winding, the spans of the nine hairpin coils of the first current loop of the first branch are 9, 9, 7, 9, 9, 10, 9, 9, 10 stator slots in sequence; the spans of the nine hairpin coils of the second and third current loops of the first branch are 9, 9, 10, 9, 9, 7, 9, 9, 10 stator slots in sequence; The spans of the nine hairpin coils of the fourth current loop of the first branch are 9, 9, 10, 9, 9, 10, 9, 9, 7 stator slots respectively; The spans of the nine hairpin coils of the first current loop of the second branch are 7, 9, 9, 10, 9, 9, 10, 9, 9 stator slots, respectively; the spans of the nine hairpin coils of the second and third current loops of the second branch are 10, 9, 9, 7, 9, 9, 10, 9, 9 stator slots, respectively; the spans of the nine hairpin coils of the fourth current loop of the second branch are 10, 9, 9, 10, 9, 9, 7, 9, 9 stator slots, respectively; The V-phase winding is formed by shifting the U-phase winding by 6 slot pitches in the direction of increasing slot position; The W-phase winding is formed by shifting the U-phase winding by 6 slot pitches in the direction of decreasing slot position.

4. The hairpin type flat wire winding according to claim 3, characterized in that: After the stator slots are expanded circumferentially along the first direction, they are numbered in the order of 1-54. The layers are numbered according to ah along the direction from the bottom of the stator slot to the slot mouth. xy is defined as the yth layer of the xth stator slot, x∈[1,54], y∈[a,h], the 1st to the 8th layers correspond to the hth to the ath layers respectively, U1+ is the initial inflow point of the first branch current on the U phase, U1- is the final outflow point of the first branch current on the U phase, and the winding connection line from U1+ to U1- of the first branch of the U phase is: 19h→10g→1h→46g→37h→30g→21h→12g→3h→48g→39h→29g→20h→11g→2h→47g→38h→28g→19f→10e→1f→46e→37f→27e→18f→9e→54f→45e→36f→29e→20f→11e→2f→47e→38f→28e→ 19d→10c→1d→46c→37d→27c→18d→9c→54d→45c→36d→29c→20d→11c→2d→47c→38d→28c→19b→10a→1b→46a→37b→27a→18b→9a→54b→45a→36b→26a→17b→8a→53b→44a→35b→28a; U2+ is the initial inflow point of the second branch current on the U phase, U2- is the final outflow point of the second branch current on the U phase, and the winding connection line from U2+ to U2- of the second branch of the U phase is: 37a→44b→53a→8b→17a→26b→35a→45b→54a→9b→18a→27b→36a→46b→1a→10b→19a→28b→37c→47d→2c→11d→20c→29d→38c→45d→54c→9d→18c→27d→36c→46d→1c→10d→19c→28d→ 37e→47f→2e→11f→20e→29f→38e→45f→54e→9f→18e→27f→36e→46f→1e→10f→19e→28f→37g→47h→2g→11h→20g→29h→38g→48h→3g→12h→21g→30h→39g→46h→1g→10h→19g→28h.

5. The hairpin flat wire winding according to claim 2, characterized in that: The three-phase windings are a U-phase winding, a V-phase winding and a W-phase winding, and the U-phase winding, the V-phase winding and the W-phase winding respectively include three parallel branches; Starting from the current inflow point, the flat wire cooperates with the hairpin coil to go around along the circumferential direction of the annular stator to the next layer, and every two layers form a current loop, and each branch of each phase has 8 current loops; When n∈[1,4], the nth current loop of the first branch is located at the 2(5-n) and 2(5-n)-1 layers, the current on the nth current loop flows into the 2(5-n) layer and flows out of the 2(5-n)-1 layer, and the hairpin coil is wound along the first direction; when n∈[5,8], the hairpin coil of the nth current loop of the first branch is located at the 2(n-4)-1 and 2(n-4) layers, the current of the nth current loop flows into the 2(n-4)-1 layer and flows out of the 2(n-4) layer, and its hairpin coil is wound along the second direction opposite to the first direction; Wherein, in the U-phase winding, the second branch is translated by 18 slot pitches along the direction of increasing slot position from the first branch, and the third branch is translated by 18 slot pitches along the direction of decreasing slot position from the first branch, and the span of the hairpin coil on each current loop of the first branch, the second branch and the third branch is 8 stator slots; The V-phase winding is formed by shifting the U-phase winding by 6 slot pitches in the direction of increasing slot position; The W-phase winding is formed by shifting the U-phase winding by 6 slot pitches in the direction of decreasing slot position.

6. The hairpin type flat wire winding according to claim 5, characterized in that: After the stator slots are expanded circumferentially along the first direction, they are numbered in the order of 1-54. The layers are numbered according to ah along the direction from the bottom of the stator slot to the slot mouth. xy is defined as the yth layer of the xth stator slot, x∈[1,54], y∈[a,h], the 1st to the 8th layers correspond to the hth to the ath layers respectively, U1+ is the initial inflow point of the first branch current on the U phase, U1- is the final outflow point of the first branch current on the U phase, and the winding connection line from U1+ to U1- of the first branch of the U phase is: 26a→17b→9a→54b→46a→37b→27c→18d→10c→1d→47c→38d→27e→18f→10e→1f→47e→38f→28g→19h→11g→2h→48g→39h→48h→3g→11h→20g→28h→37g→47f→2e→10f→19e→27f→36e→47d→2c→10d→19c→27d→36c→46b→1a→9b→18a→26b→35a; U2+ and U3+ are 44a and 8a respectively.

7. The hairpin type flat wire winding according to claim 3, characterized in that: The inlet and outlet ends of the hairpin-type flat wire winding of the two-branch connection mode are located at the welding end of the flat wire winding.

8. The hairpin type flat wire winding according to claim 5, characterized in that: The inlet and outlet ends of the hairpin-type flat wire winding of the three-branch connection mode are located at the crown end of the flat wire winding.

9. The hairpin flat wire winding according to claim 1, characterized in that: The span of the welding ends of the hairpin-type flat wire winding is 9.

Images