Flat wire motor and vehicle
By using a symmetrically distributed and rotationally symmetrical three-phase stator winding structure, combined with hairpin coils of specific span and connection methods, the problems of circulating current and production complexity in flat wire motors are solved, motor efficiency is improved and costs are reduced, and automated production is facilitated.
Patent Information
- Application Number
- CN202520150463.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-22
- Publication Date
- 2026-01-09
- Estimated Expiration
- 2035-01-22
AI Technical Summary
The existing flat wire motor stator three-phase windings are prone to circulating currents between multiple parallel branches, which leads to complex production processes and high manufacturing costs. In addition, the complex winding structure affects motor efficiency and temperature rise.
The three-phase stator windings are symmetrically distributed along the circumference of the stator core. Each phase winding includes two parallel branches that are circumferentially symmetrical. The hairpin coils contain only two spans: Z/P and (Z/P-1). The coil with a span of (Z/P-1) is located in the outermost or innermost layer. The voltage and neutral point leads are located in the same slot layer. U-type and I-type hairpin coils are used for connection, and star or delta connection is adopted.
It achieves a balanced magnetic field distribution, avoids circulating currents, improves motor efficiency, reduces production costs, facilitates automated production, and extends motor life.
Smart Images
Figure CN223785831U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of motor technology, specifically relating to flat wire motors and vehicles including such flat wire motors. Background Technology
[0002] With the promotion of new energy vehicles, electric vehicles are becoming increasingly popular, and the market demand for the performance of electric vehicle power systems is rising. The main drive motor is one of the core components of an electric vehicle, and it is developing towards higher power density and torque density, smaller size, and lighter weight. With the development of flat wire technology, electric vehicle main drive motors are gradually adopting flat wire windings, which can improve the stator slot fill factor, increase the cross-sectional area of copper conductors, reduce motor size, and further improve the motor's power density, efficiency, and thermal conductivity.
[0003] In existing technologies, flat-wire motors mainly employ wave-wound or multi-layered winding structures. By designing the flat wires in the winding structure into a multi-layered structure, the AC resistance of the motor can be effectively reduced. However, as the number of flat wires increases, the wiring method of the winding structure also changes. In existing technologies, when connecting the phase branches of the stator winding, the twisting direction at the outer end of the coil slot or the distance between the twisted slots is inconsistent. This results in a wide variety of hairpin coils being used, complex manufacturing processes, difficult forming, high production costs, and low processing efficiency. Furthermore, due to the complex motor winding structure, potential imbalances easily occur between branches of the same phase, leading to circulating currents between branches, affecting motor efficiency and temperature rise. Summary of the Invention
[0004] This utility model provides a flat wire motor and vehicle, which can solve the problems of circulating current easily generated between multiple parallel branches of the three-phase stator winding of the flat wire motor in the prior art, and the complex production process and high manufacturing cost caused by the variety of wire types of the hairpin coil.
[0005] To achieve the above-mentioned technical effects, the technical solution adopted by this utility model is a flat wire motor, including a rotor and a stator assembly, wherein the stator assembly includes:
[0006] The stator core has Z stator slots evenly distributed circumferentially on its inner wall, and each stator slot is divided into N slot layers along the radial direction of the stator core;
[0007] The three-phase stator winding is wound in the stator core and symmetrically distributed along the circumference of the stator core. Any phase winding of the three-phase stator winding includes a parallel branches, where a is 1 or 2. When a is 2, the two parallel branches are rotationally symmetrical in the circumferential direction of the stator core. Any parallel branch contains multiple hairpin coils with different spans. The hairpin coils contain only two spans: Z / P and (Z / P-1), where P is the number of motor poles. The hairpin coils with a span of (Z / P-1) are located only in the outermost or innermost layer of the stator slot. Only the hairpin coils of the same phase stator winding exist in the N slot layers of the same stator slot.
[0008] The voltage leads of the parallel branches are all located in the outermost or innermost layer of the stator slot, and the neutral point leads of the parallel branches are all located in the outermost or innermost layer of the stator slot; the voltage leads and neutral point leads of the same parallel branch are not in the same slot layer.
[0009] The span of the same-layer hairpin coil in any parallel branch is (Z / P-1) or Z / P, and the ratio of the number of hairpin coils with a span of (Z / P-1) to the number of hairpin coils with a span of Z / P is 1:3.
[0010] The span of the non-same-layer hairpin coil in any parallel branch is Z / P, and the span of the non-same-layer welding in any parallel branch is Z / P.
[0011] The hairpin coil includes a U-shaped hairpin coil and an I-shaped hairpin coil. The U-shaped hairpin coil includes a bent connecting section, two straight sections inserted into two different stator slots, and two welded sections protruding from the outer side of the end face of the stator core. The two ends of the bent connecting section are respectively connected to the same end of the two straight sections, and the same end of the two welded sections are respectively connected to the other end of the two straight sections. All the bent connecting sections of the U-shaped hairpin coils are located at one end of the stator core, forming the winding hairpin end. All the welded sections of the U-shaped hairpin coils are located at the other end of the stator core. Adjacent welded sections of adjacent U-shaped hairpin coils are welded together to form the winding welded end.
[0012] The span is the number of stator slots crossed by the two straight segments of the U-shaped hairpin coil.
[0013] The voltage lead and neutral point lead of any phase winding are connected in a star or delta configuration.
[0014] This utility model also proposes a vehicle, characterized in that it includes the above-mentioned flat wire motor.
[0015] Compared with the prior art, the present invention has the following advantages and positive effects:
[0016] 1. The flat wire motor of this utility model has three-phase stator windings symmetrically distributed along the circumference of the stator core. When any phase winding includes two parallel branches, the two parallel branches are also rotate symmetrical in the circumferential direction of the stator core. This makes the magnetic field distribution of multiple parallel branches in each phase winding the same, and the magnetomotive force is balanced. This avoids the circulating current between parallel branches, improves the efficiency of the flat wire motor, avoids local overheating of the winding, and extends the life of the flat wire motor.
[0017] 2. Any parallel branch contains multiple hairpin coils with different spans. These multiple hairpin coils contain only two spans: Z / P and (Z / P-1), where Z is the number of stator slots and P is the number of motor poles. The hairpin coil with a span of (Z / P-1) is located only in the outermost or innermost layer of the stator slot. Only hairpin coils of the same phase stator winding exist in the same stator slot. This reduces the variety of hairpin coil wire types and facilitates automated production. Attached Figure Description
[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0019] Figure 1 This is a three-dimensional structural diagram of the stator assembly of the flat wire motor in an embodiment of this utility model;
[0020] Figure 2 This is a schematic diagram of the three-dimensional structure of the stator core of the stator assembly in an embodiment of this utility model;
[0021] Figure 3 This is a schematic diagram of the distribution of the slot layers in the stator slot of the stator assembly in an embodiment of this utility model;
[0022] Figure 4 This is a schematic diagram of the U-shaped hairpin coil structure in an embodiment of this utility model;
[0023] Figure 5 This is a circuit diagram showing that the three parallel branches of each phase winding in the three-phase stator winding of the stator assembly in this utility model are connected in a star configuration.
[0024] Figure 6 This is a circuit diagram showing that the two parallel branches of each phase winding in the three-phase stator winding of the stator assembly in this utility model are connected in a delta configuration.
[0025] Figure 7This is a schematic diagram of the first parallel branch winding method of the A-phase winding of the 8-pole 48-slot flat wire motor in this embodiment of the present invention;
[0026] Figure 8 This is a schematic diagram of the second parallel branch winding method of the A-phase winding of the 8-pole 48-slot flat wire motor in an embodiment of this utility model.
[0027] Reference numerals: 10, stator assembly; 11, stator core; 12, three-phase stator winding; 13, stator slot; 20, U-shaped hairpin coil; 21, bent connection section; 22, straight section; 23, welded section. Detailed Implementation
[0028] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0029] Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.
[0030] For ease of understanding, the technical terms used in this application will be explained below.
[0031] Stator: refers to the stationary part of an electric motor, whose function is to generate a rotating magnetic field.
[0032] Rotor: refers to the rotating part in an electric motor, which is used to convert electrical energy into mechanical energy.
[0033] This utility model embodiment provides a flat wire motor, which includes a rotor and a stator assembly 10. The rotor is disposed within the space formed by the inner wall of the stator core 11 of the stator assembly 10. Figure 1 and Figure 2 As shown, the stator assembly 10 includes a stator core 11 and a three-phase stator winding 12 wound in the stator core 11. Z stator slots 13 are evenly distributed circumferentially on the inner wall of the stator core 11. Each stator slot 13 is divided into N slot layers along the radial direction of the stator core 11. The three-phase stator winding 12 is symmetrically distributed circumferentially along the stator core 11.
[0034] For example Figure 3Taking each stator slot 13 as an example, which is divided into 6 slot layers along the radial direction of the stator core 11, i.e., N=6, each stator slot 13 contains 6 layers of flat wire conductors. The first layer is denoted as D1, the second layer as D2, the third layer as D3, the fourth layer as D4, the fifth layer as D5, and the sixth layer as D6. Among them, the first slot layer is the bottom layer of the stator slot 13, and the sixth slot layer is the top layer of the slot, or the first slot layer is the top layer of the stator slot 13, and the sixth slot layer is the bottom layer of the slot.
[0035] Any one phase winding of the three-phase stator winding 12 (phase A winding, phase B winding, and phase C winding) includes a parallel branches, where a is 1 or 2. When a is 2, the two parallel branches of each phase winding are also rotationally symmetrical in the circumferential direction of the stator core 11. By limiting the two parallel branches in each phase winding to rotational symmetry in the circumferential direction, the magnetic field distribution of the two parallel branches in each phase winding is the same, and the magnetomotive force is balanced. This avoids the circulating current between the parallel branches, thereby significantly reducing the additional AC copper loss under high-speed operating conditions, improving the efficiency of the flat wire motor, and avoiding local overheating of the winding, thus extending the life of the flat wire motor.
[0036] Meanwhile, any parallel branch contains multiple hairpin coils with different spans. All hairpin coils have only two spans: Z / P and (Z / P-1), where P is the number of motor poles. Hairpin coils with a span of (Z / P-1) are located only in the outermost or innermost layer of stator slot 13. Hairpin coils of the same phase stator winding exist in N slot layers of the same stator slot 13. This reduces the number of wire types of hairpin coils, which helps to simplify the manufacturing process, reduce production costs, and facilitate automated production.
[0037] The hairpin coils of each parallel branch include U-shaped hairpin coils 20 and I-shaped hairpin coils. The I-shaped hairpin coils are the input and output terminals of each parallel branch, and the U-shaped hairpin coils 20 are located between the I-shaped hairpin coils at both ends.
[0038] like Figure 4 As shown, the U-shaped hairpin coil 20 is formed by a flat wire conductor with a rectangular cross-section, including a bent connecting section 21, two straight sections 22, and two welded sections 23. The two straight sections 22 are used to be inserted into two different stator slots 13 respectively. Both the bent connecting section 21 and the welded sections 23 protrude from the outer side of the end face of the stator core 11. The two ends of the bent connecting section 21 are respectively connected to the same end of the two straight sections 22, and the same end of the two welded sections 23 are respectively connected to the other end of the two straight sections 22. This can eliminate the potential phase difference caused by the position of multiple parallel branches in each phase winding in the stator slot 13.
[0039] by Figure 4From the perspective shown, the two ends of the bent connecting section 21 are respectively connected to the top ends of the two straight sections 22, and the top ends of the two welded sections 23 are respectively connected to the bottom ends of the two straight sections 22. All bent connecting sections 21 of the U-shaped hairpin coils 20 are located at one end of the stator core 11, forming the winding insertion end. All welded sections 23 of the U-shaped hairpin coils 20 are located at the other end of the stator core 11. Adjacent welded sections 23 of adjacent U-shaped hairpin coils 20 are welded together to form the winding welding end. For example, the bottom end of the right welded section 23 of the left U-shaped hairpin coil 20 is welded to the bottom end of the left welded section 23 of the right U-shaped hairpin coil 20. The span refers to the number of stator slots 13 crossed by the two straight sections 22 of the U-shaped hairpin coil 20; the welding pitch between hairpin coils is the number of stator slots crossed by the adjacent straight sections 22 of two adjacent hairpin coils.
[0040] The type I hairpin coil is equivalent to half the size of the type U hairpin coil (20). Figure 4 From the perspective shown, the type I hairpin coil is equivalent to the left or right half of the type U hairpin coil 20, and its structure will not be described in detail.
[0041] In one embodiment, the U-shaped hairpin coil 20 can be inserted into the stator slot 13 and then bent to form a welding section 23. After the U-shaped hairpin coil 20 is inserted into the stator slot 13, its bent connecting section 21 forms the winding insertion end, and the welding section 23 forms the winding welding end.
[0042] Furthermore, the voltage leads of the parallel branches are all located in the outermost or innermost layer of stator slot 13, and the neutral point leads of the parallel branches are all located in the outermost or innermost layer of stator slot 13; the voltage leads and neutral point leads of the same parallel branch are not in the same slot layer; thus facilitating the welding of motor terminals and busbars and improving motor production efficiency.
[0043] Furthermore, the span of the same-layer hairpin coil in any parallel branch is (Z / P-1) or Z / P, and the ratio of the number of hairpin coils with a span of (Z / P-1) to the number of hairpin coils with a span of Z / P is 1:3.
[0044] The span of the non-same-layer hairpin coil in any parallel branch is Z / P, and the span of the non-same-layer welding in any parallel branch is Z / P. That is, the span of the non-same-layer hairpin coil and the non-same-layer welding span in any parallel branch are equal, which makes the number of U-shaped hairpin coil 20 wire types small and the welding span only one, further facilitating welding and automated manufacturing.
[0045] The following embodiments use a flat wire motor with 8 poles P, 48 stator slots Z, 6 slot layers in each stator slot 13, and 2 parallel branches in each phase winding of the three-phase stator winding 12 as examples to illustrate in detail the winding structure of each phase winding of the flat wire motor of this utility model.
[0046] The U-shaped hairpin coil 20 of the stator assembly 10 in this embodiment has only two spans: (Z / P-1) and Z / P, i.e., 5 and 6. The stator assembly 10 is composed of three-phase stator windings 12 (A-phase winding, B-phase winding and C-phase winding) with a phase difference of 120 electrical degrees, and the three-phase stator windings 12 are wound in the stator core 11.
[0047] The voltage lead and neutral point lead of any phase winding are connected in a star or delta configuration, such as... Figure 5 and Figure 6 As shown.
[0048] Slot number i(j) represents the j-th slot layer in the i-th slot. For example, 38(1) represents the 1st slot layer in the 38th slot, or simply the 1st slot layer in the 38th slot. 44(2) represents the 2nd slot layer in the 44th slot, or simply the 2nd slot layer in the 44th slot. The other slot numbers below are explained in the same way.
[0049] like Figure 7 As shown, the horizontally arranged numbers 1 to 48 represent the slot numbers, and they are arranged in a ring. Figure 2 As shown; the vertically arranged numbers 1 to 6 represent slot layers, with a total of 6 slot layers. Solid lines with arrows represent the wiring method of the winding insertion terminals; each solid line with an arrow represents a U-shaped hairpin coil 20. Dashed lines with arrows represent the wiring method of the winding welding terminals; each dashed line with an arrow represents the welding line between adjacent welding terminals of two adjacent U-shaped hairpin coils 20. A1 and A2 can be used as voltage leads or neutral point leads. Correspondingly, X1 and X2 can be used as voltage leads or neutral point leads. For example, A1 can be used as the voltage lead of the first parallel branch of phase A, and X1 as the neutral point lead of the first parallel branch of phase A; A2 can be used as the voltage lead of the second parallel branch of phase A, and X2 as the neutral point lead of the second parallel branch of phase A.
[0050] Similarly, B1 and B2 can be used as voltage leads for phase B or as neutral point leads. Correspondingly, Y1 and Y2 can be used as voltage leads or as neutral point leads. For example, B1 can be used as the voltage lead for the first parallel branch of phase B, and Y1 can be used as the neutral point lead for the first parallel branch of phase B; B2 can be used as the voltage lead for the second parallel branch of phase B, and Y2 can be used as the neutral point lead for the second parallel branch of phase B.
[0051] C1 and C2 can be used as voltage leads for phase C or as neutral point leads. Similarly, Z1 and Z2 can be used as voltage leads or as neutral point leads. For example, C1 can be used as the voltage lead for the first parallel branch of phase C, and Z1 can be used as the neutral point lead for the first parallel branch of phase C; C2 can be used as the voltage lead for the second parallel branch of phase C, and Z2 can be used as the neutral point lead for the second parallel branch of phase C.
[0052] like Figure 7 As shown, the first parallel branch of phase A enters from the first layer of slot 38 and exits from the sixth layer of slot 7 to the three-phase center point. The slot numbers traversed by the first parallel branch in series are:
[0053] 38(1)-44(2)-2(1)-8(2)-14(1)-20(2)-26(1)-32(2)-38(3)-44(4)-2(3)-8(4)-14(3)-20(4)-26(3)-32(4)-38(5)-44(6)-2(5)-8(6)-14(5)-20(6)-26(5)-32(6)-3 7(6)-31(5)-25(4)-19(3)-13(2)-7(1)-13(1)-19(2)-25(3)-31(4)-37(5)-43(6)-1(6)-43(5)-37(4)-31(3)-25(2)-19(1)-25(1)-31(2)-37(3)-43(4)-1(5)-7(6).
[0054] like Figure 8 As shown, the second parallel branch of phase A enters from the 6th layer of slot 38 and exits from the 1st layer of slot 31 to the three-phase center point. The slot numbers traversed by the second parallel branch in series are:
[0055] 38(6)-32(5)-26(6)-20(5)-14(6)-8(5)-2(6)-44(5)-38(4)-32(3)-26(4)-20(3)-14(4)-8(3)-2(4)-44(3)-38(2)-32(1)-26(2)-20(1)-14(2)-8(1)-2(2)-44(1) -1(1)-7(2)-13(3)-19(4)-25(5)-31(6)-25(6)-19(5)-13(4)-7(3)-1(2)-43(1)-37(1)-43(2)-1(3)-7(4)-13(5)-19(6)-13(6)-7(5)-1(4)-43(3)-37(2)-31(1).
[0056] The starting and ending slot numbers corresponding to the two parallel branch windings are distributed as follows: A1 corresponds to 38(1), X1 corresponds to 7(6); A2 corresponds to 38(6), X2 corresponds to 31(1); the span of the same layer of the first parallel branch of phase A is 5 or 6, and the number of the hairpin coil with a span of 5 is 1, and the number of the hairpin coil with a span of 6 is 3, with a ratio of 1:3. The span of the same layer of the hairpin coil of the second parallel branch of phase A is 5 or 6, and the number of the hairpin coil with a span of 5 is 1, and the number of the hairpin coil with a span of 6 is 3, with a ratio of 1:3.
[0057] The non-coiled hairpin coils of the two parallel branches have a span of 6, the non-coiled welding span is 6, the winding coils of the two parallel branches have the same span and the same resistance value, the circumference is completely symmetrical, and there is no potential difference causing branch circulating current.
[0058] The A-phase winding, B-phase winding, and C-phase winding are symmetrically and evenly distributed on the circumference of the stator core 11. The winding method of the B-phase winding and C-phase winding will not be described in detail here.
[0059] This embodiment also proposes a vehicle including the aforementioned flat wire motor.
[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.
Claims
1. A flat wire motor, comprising a rotor and a stator assembly, characterized in that, The stator assembly includes: The stator core has Z stator slots evenly distributed circumferentially on its inner wall, and each stator slot is divided into N slot layers along the radial direction of the stator core; The three-phase stator winding is wound in the stator core and symmetrically distributed along the circumference of the stator core. Any phase winding of the three-phase stator winding includes a parallel branches, where a is 1 or 2. When a is 2, the two parallel branches are rotationally symmetrical in the circumferential direction of the stator core. Any parallel branch contains multiple hairpin coils with different spans. The hairpin coils contain only two spans: Z / P and (Z / P-1), where P is the number of motor poles. The hairpin coils with a span of (Z / P-1) are located only in the outermost or innermost layer of the stator slot. Only the hairpin coils of the same phase stator winding exist in the N slot layers of the same stator slot.
2. The flat wire motor according to claim 1, characterized in that, The voltage leads of the parallel branches are all located in the outermost or innermost layer of the stator slot, and the neutral point leads of the parallel branches are all located in the outermost or innermost layer of the stator slot; the voltage leads and neutral point leads of the same parallel branch are not in the same slot layer.
3. The flat wire motor according to claim 1, characterized in that, The span of the same-layer hairpin coil in any parallel branch is (Z / P-1) or Z / P, and the ratio of the number of hairpin coils with a span of (Z / P-1) to the number of hairpin coils with a span of Z / P is 1:
3.
4. The flat wire motor according to any one of claims 1 to 3, characterized in that, The span of the non-same-layer hairpin coil in any parallel branch is Z / P, and the span of the non-same-layer welding in any parallel branch is Z / P.
5. The flat wire motor according to claim 1, characterized in that, The hairpin coil includes a U-shaped hairpin coil and an I-shaped hairpin coil. The U-shaped hairpin coil includes a bent connecting section, two straight sections inserted into two different stator slots, and two welded sections protruding from the outer side of the end face of the stator core. The two ends of the bent connecting section are respectively connected to the same end of the two straight sections, and the same end of the two welded sections are respectively connected to the other end of the two straight sections. All the bent connecting sections of the U-shaped hairpin coils are located at one end of the stator core, forming the winding hairpin end. All the welded sections of the U-shaped hairpin coils are located at the other end of the stator core. Adjacent welded sections of adjacent U-shaped hairpin coils are welded together to form the winding welded end. The span is the number of stator slots crossed by the two straight segments of the U-shaped hairpin coil.
6. A flat wire motor according to claim 2, characterized in that, The voltage lead and neutral point lead of any phase winding are connected in a star or delta configuration.
7. A vehicle, characterized in that, The flat wire motor includes any one of claims 1 to 6.