Hairpin type flat wire winding
By using specific flat conductor arrangement on the ring stator, hairpin flat wire windings are formed, the magnetomotive force harmonic problem in traditional winding design is solved, the torque stability and NVH performance of the motor are improved, and the torque stability and NVH performance are improved. Motor efficiency.
Patent Information
- Application Number
- CN202411521470.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-29
- Publication Date
- 2025-02-14
AI Technical Summary
The traditional Hairpin flat wire motor winding design is designed in a 6-layer flat wire three-phase motor with 3 slots per pole and 3. It is difficult to avoid the generation of magnetic force harmonics, resulting in output torque fluctuations, NVH noise difference, low efficiency, etc. question.
Using a specific flat conductor arrangement method, the ring-shaped stator is arranged for one cycle, specifically: 6 layers of first phase conductor, 6 layers of first phase conductor, 2 layers of second phase conductor + 4 layers of first phase conductor , 6 layers of second phase conductor, 6 layers of second phase conductor, 2 layers of third phase conductor + 4 layers of second phase conductor, 6 layers of third phase conductor, 6 layers of third phase conductor, 2 layers of first phase conductor + 4 layers of third-phase conductors form hairpin flat wire windings.
The magnetomotive force harmonics of the winding are significantly reduced, the torque stability and NVH performance of the motor are improved, and the motor efficiency is improved.
Smart Images
Figure CN119448627A_ABST
Abstract
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, for a 6-layer flat wire three-phase motor with 3 slots per pole per phase, the traditional Hairpin flat wire motor winding design is usually a full-pitch winding, which inevitably produces higher magnetomotive force harmonics. These harmonics not only increase the electromagnetic load of the motor, but also lead to significant fluctuations in the output torque, poor NVH noise performance, large harmonic magnetic field losses, and low motor efficiency, thereby affecting 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 effectively reduce the magnetomotive force harmonics of the winding, thereby improving the performance of the motor.
[0005] In order to achieve the above object, the present invention provides a hairpin flat wire winding for a motor having three slots per pole and per phase, wherein the hairpin flat wire winding comprises a three-phase winding, each phase winding comprises a plurality of parallel branches, each branch comprises a plurality of hairpin coils connected in series, 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 six 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: 6 layers of first phase conductors, 6 layers of first phase conductors, 2 layers of second phase conductors + 4 layers of first phase conductors, 6 layers of second phase conductors, 6 layers of second phase conductors, 2 layers of third phase conductors + 4 layers of second phase conductors, 6 layers of third phase conductors, 6 layers of third phase conductors, 2 layers of first phase conductors + 4 layers of third phase conductors;
[0007] The arrangement is cyclically arranged on the annular stator.
[0008] In some embodiments, the number of stator slots is 18 or 36 or 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 three current loops;
[0011] When n∈[1,3], the hairpin coils of the nth current loops of the first branch and the second branch are located at the 2nd (4-n) layer and the 2nd (4-n)-1 layer, the current on the nth current loop flows into the 2nd (4-n) layer and flows out of the 2nd (4-n)-1 layer, and the hairpin coils are wound along the first direction;
[0012] Among them, in the U-phase winding, the first branch of the U-phase winding is translated by 9 slot pitches along the increasing direction of the slot position to form the second branch of the U-phase winding, and the spans of the nine hairpin coils of the first current loop of the first branch and the second branch are 10, 9, 9, 7, 9, 9, 10, 9, and 9 stator slots respectively; the spans of the nine hairpin coils of the second and third current loops of the first branch and the second branch are 7, 9, 9, 10, 9, 9, 10, 9, and 9 stator slots respectively;
[0013] The V-phase winding is formed by shifting the U-phase winding by 6 slot pitches in the direction of increasing slot position;
[0014] The W-phase winding is formed by shifting the U-phase winding by 6 slot pitches in the direction of decreasing slot position.
[0015] In some embodiments, the stator slots are expanded circumferentially along a 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 mouth according to af, and xy is defined as the yth layer of the xth stator slot, x∈[1,54], y∈[a,f], the 1st to 6th layers correspond to the fth to 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:
[0016] 28a→18b→9a→54b→45a→36b→27a→20b→11a→2b→47a→38b→29a→19b→10a→1b→46a→37b→28c→21d→12c→3d→48c→39d→30c→20d→11c→2d→47c→38d→29c→19d→10c→1d→46c→37d→28e→21f→12e→3f→48e→39f→30e→20f→11e→2f→47e→38f→29e→19f→10e→1f→46e→37f; U2+ is 37a.
[0017] 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 three parallel branches;
[0018] 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 6 current loops;
[0019] When n∈[1,3], the nth current loop of the first branch is located at the 2n-1 and 2n layers, 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; when n∈[4,6], the hairpin coil of the nth current loop of the first branch is located at the 2(n-3)-1 and 2(n-3) layers, the current of the nth current loop flows into the 2(n-3)-1 layer and flows out of the 2(n-3) layer, and its hairpin coil is wound along the second direction opposite to the first direction;
[0020] Wherein, in the U-phase winding, the second branch is shifted by 1 slot pitch along the direction of increasing slot positions from the first branch, and the third branch is shifted by 1 slot pitch along the direction of increasing slot positions from the second branch, and the span of the hairpin coils on each current loop of the first branch, the second branch and the third branch is 9 stator slots;
[0021] The W-phase winding is formed by shifting the U-phase winding by 6 slot pitches in the direction of decreasing slot position;
[0022] The V-phase winding is formed by shifting the W-phase winding by 6 slot pitches in the direction of decreasing slot position.
[0023] In some embodiments, the stator slots are expanded circumferentially along a 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 mouth according to af, and xy is defined as the yth layer of the xth stator slot, x∈[1,54], y∈[a,f], the 1st to 6th layers correspond to the fth to 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:
[0024] 37f→28e→19f→10e→1f→46e→39d→30c→21d→12c→3d→48c→37b→28a→19b→10a→1b→46a→1a→10b→19a→28b→37a→46b→3c→12d→21c→30d→39c→48d→1e→10f→19e→28f→37e→46f; U2+ and U3+ are 38f and 39f respectively.
[0025] 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.
[0026] 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.
[0027] In some embodiments, the span of the welding ends of the hairpin-type flat wire winding is 9.
[0028] 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 circle, specifically: 6 layers of first phase conductors, 6 layers of first phase conductors, 2 layers of second phase conductors + 4 layers of first phase conductors, 6 layers of second phase conductors, 6 layers of second phase conductors, 2 layers of third phase conductors + 4 layers of second phase conductors, 6 layers of third phase conductors, 6 layers of third phase conductors, 2 layers of first phase conductors + 4 layers of third 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
[0029] 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;
[0030] Figure 2 It is a schematic diagram of the distribution of three-phase conductors in the slots of a conventional winding;
[0031] Figure 3It is a schematic diagram of the expansion of the first branch winding of the U phase of a two-branch connection mode of a 6-pole 54-slot 6-layer flat wire three-phase motor provided by an embodiment of the present invention;
[0032] Figure 4 It is a schematic diagram of the expansion of the U-phase winding of a two-branch connection mode of a 6-pole 54-slot 6-layer flat wire three-phase motor provided by an embodiment of the present invention;
[0033] Figure 5 It is a schematic diagram of the expansion of the three-phase winding of a three-phase motor with six poles, five slots and six layers of flat wires in a two-branch connection mode provided by an embodiment of the present invention;
[0034] Figure 6 It is a schematic diagram of the expansion of the U-phase winding of a three-branch connection mode of a 6-pole 54-slot 6-layer flat wire three-phase motor provided by an embodiment of the present invention;
[0035] Figure 7 It is a schematic diagram of the three-phase winding expansion of a three-branch connection mode of a 6-pole 54-slot 6-layer flat wire three-phase motor provided by an embodiment of the present invention;
[0036] Figure 8 It is a schematic diagram of the conductor distribution in a single stator slot in the present invention. DETAILED DESCRIPTION
[0037] 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.
[0038] For ease of understanding, the terms mentioned in the present invention are explained below.
[0039] 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.
[0040] 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.
[0041] 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.
[0042] 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 The conventional full-pitch flat wire winding shown in .
[0043] The hairpin 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 in a three-phase parallel manner on an annular stator having a plurality of slots, and each stator slot being wound with 6 layers of flat wire conductors;
[0044] 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: 6 layers of first phase conductors, 6 layers of first phase conductors, 2 layers of second phase conductors + 4 layers of first phase conductors, 6 layers of second phase conductors, 6 layers of second phase conductors, 2 layers of third phase conductors + 4 layers of second phase conductors, 6 layers of third phase conductors, 6 layers of third phase conductors, 2 layers of first phase conductors + 4 layers of third 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.
[0045] The hairpin flat wire winding of the present invention can be used for a 6-layer flat wire three-phase motor with Q=3 slots per pole per phase, such as a motor with 2 poles and 18 slots, 4 poles and 36 slots, 6 poles and 54 slots, or 8 poles and 72 slots.
[0046] 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.
[0047] 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.
[0048] By placing the winding ( Figure 1 ) and traditional winding 1( Figure 2 ) 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:
[0049] Table 1 Magnetomotive force harmonic values of conventional windings and windings of the present invention
[0050]
[0051] 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 and 13th harmonics of the winding magnetomotive force compared with the traditional winding.
[0052] The solution provided by the embodiment of the present invention is described in detail below through specific examples.
[0053] Embodiment 1
[0054] 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.
[0055] In the present invention, the number of conductor layers in each stator slot is 6, that is, each stator slot has a 6-layer structure, the layer close to the slot opening is the first layer, and the layer close to the slot bottom is the sixth layer.
[0056] 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 af, such as Figure 8 As shown, xy is defined as the yth layer of the xth stator slot, x∈[1,54], y∈[a,f], and the 1st to 6th layers correspond to the fth to ath layers respectively.
[0057] In the present invention, the three phases are U phase, V phase and W phase.
[0058] 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, af 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):
[0059]
[0060] According to the arrangement of Table 2, further, when each phase winding has two branches, such as Figure 4 As shown, the U-phase winding includes two branches, namely the U-phase first branch (i.e. Figure 4 U1 in the U phase), the second branch of the U phase (i.e. Figure 4 2).
[0061] like Figure 4 As shown, the V-phase winding includes two branches, namely the first branch of the V-phase (i.e. Figure 5 V1 in the V phase), the second branch of the V phase (i.e. Figure 5 V2 in the W phase winding); the W phase winding includes two branches, namely the W phase first branch (i.e. Figure 5 W1 in the W phase), the second branch of the W phase (i.e. Figure 5 W2 in ).
[0062] 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 three 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.
[0063] Specifically, when n∈[1,3], the hairpin coils of the nth current loops of the first branch and the second branch are located at the 2nd (4-n) layer and the 2nd (4-n)-1 layer, the current on the nth current loop flows into the 2nd (4-n) layer and flows out of the 2nd (4-n)-1 layer, and the hairpin coils are wound along the first direction ( Figure 4 from right to left in the middle).
[0064] Current loop is a term defined in this application to describe the cross-layer connection method of the hairpin coil.
[0065] That is, the hairpin coils of the first current loop of the first branch and the second branch flow in from the sixth layer (layer a) and flow out from the fifth layer (layer b), the hairpin coils of the second current loop flow in from the fourth layer (layer c) and flow out from the third layer (layer d), and the hairpin coils of the third current loop flow in from the second layer (layer e) and flow out from the first layer (layer f).
[0066] The specific winding method is that, in the U-phase winding, the first branch of the U-phase winding is translated by 9 slots along the increasing direction of the slot position to form the second branch of the U-phase winding, and the spans of the nine hairpin coils of the first current loop of the first branch and 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 second and third current loops of the first branch and the second branch are 7, 9, 9, 10, 9, 9, 10, 9, 9 stator slots respectively;
[0067] The V-phase winding is formed by shifting the U-phase winding by 6 slot pitches in the direction of increasing slot position;
[0068] The W-phase winding is formed by shifting the U-phase winding by 6 slot pitches in the direction of decreasing slot position.
[0069] Specifically, Figure 4As 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.
[0070] When U1+ is 28a, the connection line from U1+ to U1- of the first branch of phase U is:
[0071] 28a→18b→9a→54b→45a→36b→27a→20b→11a→2b→47a→38b→29a→19b→10a→1b→46a→37b→28c→21d→12c→3d→48c→39d→30c→20d→11c→2d→47c→38d→29c→19d→10c→1d→46c→37d→28e→21f→12e→3f→48e→39f→30e→20f→11e→2f→47e→38f→29e→19f→10e→1f→46e→37f.
[0072] That is, one effective side of the first hairpin coil of the first branch is located at the a layer of slot No. 28, and the other effective side is located at the b layer of slot No. 18, that is, the current flows into the a layer of slot No. 28 and flows out from the b layer of slot No. 18, with a span of 10 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.
[0073] Similarly, one effective side of the second hairpin coil of the first branch is located at the a layer of slot No. 9, and the other effective side is located at the b layer of slot No. 54, that is, the current flows into the a layer of slot No. 9 and flows out from the b layer of slot No. 54, 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.
[0074] By analogy, the first to ninth hairpin coils 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 first to third current loops 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 (layer b of slot No. 37) to the right end of the tenth hairpin coil (layer c of slot No. 28); and flows out from the left end of the eighteenth hairpin coil (layer d of slot No. 37) to the right end of the nineteenth hairpin coil (layer e of slot No. 28).
[0075] The current flow direction from the first current loop to the third current loop of the first branch on the U phase is a, b layer →c, d layer →e, f layer, and the left end of the previous hairpin and the right end of the next hairpin are welded.
[0076] Since the winding method of the second branch of the U-phase winding is that the first branch of the U-phase winding is shifted 9 slot pitches in the direction of increasing slot position, that is, the second branch of the U-phase flows into the a-th layer of slot No. 37 and finally flows out from the f-th layer of slot No. 46, its detailed connection route will not be repeated.
[0077] 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 ath layer of slot No. 34 and finally flows out from the fth layer of slot No. 43, and the second branch flows into the ath layer of slot No. 43 and finally flows out from the fth layer of slot No. 52, the detailed connection route will not be repeated.
[0078] Since the winding method of the W-phase winding is to shift the U-phase winding by 6 slot pitches in the direction of decreasing slot position, that is, the first branch of the V-phase flows in from the a-th layer of slot No. 22 and finally flows out from the f-th layer of slot No. 31, and the second branch flows in from the a-th layer of slot No. 31 and finally flows out from the f-th layer of slot No. 40, the detailed connection route will not be repeated.
[0079] 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 5 shown).
[0080] like Figure 6 As shown, when each phase winding has three branches, the U-phase winding includes three 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 U2 in the U phase), the third branch of the U phase (i.e. Figure 6 in U3).
[0081] like Figure 7 As shown, the V-phase winding includes three 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 V phase), the third branch of the V phase (i.e. Figure 7 V3 in the figure); the W-phase winding includes three branches, namely the first branch of the W-phase (i.e. Figure 7 W1 in the W phase), the second branch of the W phase (i.e. Figure 7 W2 in the W phase), the third branch of the W phase (i.e. Figure 7 in W3).
[0082] 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 6 current loops;
[0083] When n∈[1,3], the nth current loop of the first branch is located at the 2n-1 and 2n layers, 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 When n∈[4,6], the hairpin coil of the nth current loop of the first branch is located at the 2(n-3)-1 and 2(n-3) layers, and the current of the nth current loop flows into the 2(n-3)-1 layer and flows out of the 2(n-3) layer. The hairpin coil is wound in a second direction opposite to the first direction ( Figure 6 (from left to right in the middle);
[0084] 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 6 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.
[0085] That is, the current of the first current loop of the first branch flows into the first layer (layer f) and flows out from the second layer (layer e); the current of the second current loop flows in from the third layer (layer d) and flows out from the fourth layer (layer c); the current of the third current loop flows in from the fifth layer (layer b) and flows out from the sixth layer (layer a); the current of the fourth current loop flows in from the sixth layer (layer a) and flows out from the fifth layer (layer b); the current of the fifth current loop flows in from the fourth layer (layer c) and flows out from the third layer (layer d); the current of the sixth current loop flows in from the second layer (layer e) and flows out from the first layer (layer f).
[0086] 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 9 stator slots; the second branch is shifted by 1 slot pitch along the direction of increasing slot positions from the first branch, and the third branch is shifted by 1 slot pitch along the direction of increasing slot positions from the second branch. The span of the hairpin coil on each current loop of the first branch, the second branch and the third branch is 9 stator slots.
[0087] The W-phase winding is formed by shifting the U-phase winding by 6 slot pitches in the direction of decreasing slot position;
[0088] The V-phase winding is formed by shifting the W-phase winding by 6 slot pitches in the direction of decreasing slot position.
[0089] Specifically, combined 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, 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.
[0090] When U1+ is 37f, the connection line from U1+ to U1- of the first branch of phase U is:
[0091] 37f→28e→19f→10e→1f→46e→39d→30c→21d→12c→3d→48c→37b→28a→19b→10a→1b→46a→1a→10b→19a→28b→37a→46b→3c→12d→21c→30d→39c→48d→1e→10f→19e→28f→37e→46f.
[0092] That is, one effective side of the first hairpin coil of the first branch is located at the e layer of slot No. 28, and the other effective side is located at the f layer of slot No. 19, that is, the current flows into the e layer of slot No. 28 and flows out from the f layer of slot No. 19, 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.
[0093] Similarly, one effective side of the second hairpin coil of the first branch is located at the e layer of slot No. 10, and the other effective side is located at the f layer of slot No. 1, that is, the current flows into the e layer of slot No. 10 and flows out from the f layer of slot No. 1, 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.
[0094] One effective side of the third hairpin coil of the first branch is located at the e layer of slot No. 46, and the other effective side is located at the d layer of slot No. 39, that is, the current flows into the e layer of slot No. 46 and flows out from the d layer of slot No. 39, with a span of 7 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.
[0095] 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 sixth current loop are located at the f, e layers, d, c layers, b, a layers, a, b layers, c, d layers, e, f layers respectively. The first current loop to the sixth current loop are connected in sequence, among which the third, sixth, ninth, twelfth, and fifteenth hairpin coils are located on two adjacent current loops, and their spans are 7, 11, 9, 11, and 7 respectively. Except for the third, sixth, ninth, twelfth, and fifteenth hairpin coils, the spans of the hairpin coils are all 9.
[0096] The current flow direction from the first current loop to the fourth current loop of the first branch on the U phase is f, e layer → d, c layer → b, a layer, and the left end of the previous hairpin and the right end of the next hairpin are welded.
[0097] The current flow direction from the fifth current loop to the eighth current loop of the first branch on the U phase is a, b layer → c, d layer → e, f layer; the right end of the previous hairpin and the left end of the next hairpin are welded.
[0098] 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 is 38f, and the span of each hairpin coil on the second branch and the first branch is consistent, the winding connection line of the second branch of the U phase flows in from 38f and finally flows out from 46f can be obtained; according to the current inflow point U3+ of the third branch of the U phase is 39f, and the span of each hairpin coil on the third branch and the first branch is consistent, the winding connection line of the third branch of the U phase flows in from 39f and finally flows out from 48f can be obtained; as shown in FIG. Figure 6 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.
[0099] Since the winding method of the W-phase winding is to shift the U-phase winding by 6 slot pitches in the direction of decreasing slot position, that is, the first branch of the W-phase flows in from the f-th layer of slot No. 31 and finally flows out from the f-th layer of slot No. 40, the second branch flows in from the f-th layer of slot No. 32 and finally flows out from the f-th layer of slot No. 41, and the third branch flows in from the f-th layer of slot No. 33 and finally flows out from the f-th layer of slot No. 42, the detailed connection routes will not be repeated here.
[0100] Since the winding method of the V-phase winding is to shift the W-phase winding by 6 slot pitches in the direction of decreasing slot position, that is, the first branch of the W-phase flows in from the f-th layer of slot No. 25 and finally flows out from the f-th layer of slot No. 34, the second branch flows in from the f-th layer of slot No. 26 and finally flows out from the f-th layer of slot No. 35, and the third branch flows in from the f-th layer of slot No. 27 and finally flows out from the f-th layer of slot No. 36, the detailed connection routes will not be repeated here.
[0101] 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.
[0102] 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 as specified in the present embodiment has different slot number marks under different unfolding methods. The technicians in this field may obtain different winding connection line combinations by connecting the current from different slot numbers according to the winding method given in the embodiment of the present invention. 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 f 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 6 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: 6 layers of first phase conductors, 6 layers of first phase conductors, 2 layers of second phase conductors + 4 layers of first phase conductors, 6 layers of second phase conductors, 6 layers of second phase conductors, 2 layers of third phase conductors + 4 layers of second phase conductors, 6 layers of third phase conductors, 6 layers of third phase conductors, 2 layers of first phase conductors + 4 layers of third 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 18, 36, 54 or 72.
3. 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 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 three current loops; When n∈[1,3], the hairpin coils of the nth current loops of the first branch and the second branch are located at the 2nd (4-n) layer and the 2nd (4-n)-1 layer, the current on the nth current loop flows into the 2nd (4-n) layer and flows out of the 2nd (4-n)-1 layer, and the hairpin coils are wound along the first direction; Among them, in the U-phase winding, the first branch of the U-phase winding is translated by 9 slot pitches along the increasing direction of the slot position to form the second branch of the U-phase winding, and the spans of the nine hairpin coils of the first current loop of the first branch and the second branch are 10, 9, 9, 7, 9, 9, 10, 9, and 9 stator slots respectively; the spans of the nine hairpin coils of the second and third current loops of the first branch and the second branch are 7, 9, 9, 10, 9, 9, 10, 9, and 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 af 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,f], the 1st to 6th layers correspond to the fth to 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: 28a→18b→9a→54b→45a→36b→27a→20b→11a→2b→47a→38b→29a→19b→10a→1b→46a→37b→28c→21d→12c→3d→48c→39d→30c→20d→11c→2d→47c→38d→29c→19d→10c→1d→46c→37d→28e→21f→12e→3f→48e→39f→30e→20f→11e→2f→47e→38f→29e→19f→10e→1f→46e→37f; U2+ is 37a.
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 to the next layer along the circumferential direction of the annular stator, and every two layers form a current loop, and each branch of each phase has 6 current loops; When n∈[1,3], the nth current loop of the first branch is located at the 2n-1 and 2n layers, 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; when n∈[4,6], the hairpin coil of the nth current loop of the first branch is located at the 2(n-3)-1 and 2(n-3) layers, the current of the nth current loop flows into the 2(n-3)-1 layer and flows out of the 2(n-3) 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 shifted by 1 slot pitch along the direction of increasing slot positions from the first branch, and the third branch is shifted by 1 slot pitch along the direction of increasing slot positions from the second branch, and the span of the hairpin coils on each current loop of the first branch, the second branch and the third branch is 9 stator slots; The W-phase winding is formed by shifting the U-phase winding by 6 slot pitches in the direction of decreasing slot position; The V-phase winding is formed by shifting the W-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 af 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,f], the 1st to 6th layers correspond to the fth to 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: 37f→28e→19f→10e→1f→46e→39d→30c→21d→12c→3d→48c→37b→28a→19b→10a→1b→46a→1a→10b→19a→28b→37a→46b→3c→12d→21c→30d→39c→48d→1e→10f→19e→28f→37e→46f; U2+ and U3+ are 38f and 39f 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.