Stator, motor and vehicle

Abstract

The invention provides a stator, a motor and a vehicle, the stator comprises a stator core and a three-phase stator winding, and Z stator slots are uniformly distributed on the inner wall of the stator core along the circumferential direction; any phase winding comprises a parallel branches, a is 1 or 2, and when a is 2, the two parallel branches are rotationally symmetrical in the circumferential direction of the stator core; any parallel branch comprises a plurality of hairpin coils with different spans, the hairpin coils only comprise two spans of Z / P and (Z / P + 1), and the hairpin coils with the spans of (Z / P + 1) are only located on the outermost layer or the innermost layer of the stator slots; and only the hairpin coil of the stator winding of the same phase exists in the same stator slot. According to the flat wire motor, the magnetic field distribution of a plurality of parallel branches in each phase of winding is the same, the magnetic potential is balanced, ring current among the parallel branches is avoided, the efficiency of the flat wire motor is improved, local temperature rise and over-temperature of the winding are avoided, and the service life of the flat wire motor is prolonged.

Description

Technical Field

[0001] The present invention belongs to the technical field of motors, and in particular relates to a stator, a motor and a vehicle. Background Art

[0002] With the promotion of new energy vehicles, new energy electric vehicles are becoming more and more popular, and the market demand for the performance of electric vehicle power systems is getting higher and higher. The main drive motor is one of the core components of electric vehicles, and is developing in the direction of high power density and high torque density, small size and light weight. With the development of flat wire technology, the main drive motor of electric vehicles gradually adopts flat wire winding, which can improve the slot fill rate of the stator, increase the cross-sectional area of ​​the copper conductor, reduce the size of the motor, and further improve the power density, efficiency and thermal conductivity of the motor.

[0003] In the prior art, flat wire motors mainly use a winding structure of wave winding or laminated winding. By designing the flat wire conductors in the winding structure into a multi-layer structure, the AC resistance of the motor can be effectively reduced. However, as the number of flat wire conductors increases, the wiring method of the winding structure is also different. In the prior art, when the phase branches of the stator winding are connected, the torsion direction of the outer end of the coil slot or the distance between the torsion slots is inconsistent, the hairpin coils used are of various types, the manufacturing process is complex, the forming is difficult, the production cost is high, and the processing efficiency is low. In addition, due to the complex structure of the motor winding, potential imbalance is prone to occur between the same-phase branches, resulting in the formation of circulating currents between the branches, affecting the efficiency and temperature rise of the motor. Summary of the invention

[0004] The present invention provides a stator, a motor and a vehicle, which can solve the problems in the prior art that circulating current is easily generated between multiple parallel branches of the three-phase winding of the motor stator, and the production process is complicated and the manufacturing cost is high due to the variety of line types of hairpin coils.

[0005] In order to achieve the above technical effects, the technical solution adopted by the stator of the present invention is a stator, comprising: A stator core, the inner wall of which is uniformly provided with Z stator slots along the circumferential direction, each of the stator slots being divided into N slot layers along the radial direction of the stator core; A three-phase stator winding is wound in the stator core and symmetrically distributed along the circumference of the stator core; any one phase of the three-phase stator winding includes a parallel branches, a is 1 or 2, and when a is 2, the two parallel branches are rotationally symmetrical in the circumferential direction of the stator core; any one parallel branch contains a plurality of hairpin coils with different spans, and the hairpin coils only contain two spans of Z / P and (Z / P+1), and P is the number of motor poles; any one parallel branch has hairpin coils with two spans of Z / P and (Z / P+1), and the hairpin coil with a span of (Z / P+1) is only located in the outermost layer or the innermost layer of the stator slot; only hairpin coils of the same phase stator winding exist in the N slot layers of the same stator slot.

[0006] The technical solution of the stator of the present invention also includes the following additional technical features: The voltage lead wires of the a parallel branches are all located at the outermost layer or the innermost layer of the stator slots, and the neutral point lead wires of the a parallel branches are all located at the outermost layer or the innermost layer of the stator slots.

[0007] The span of the card issuing coils of the same layer in the outermost or innermost layer of any parallel branch is (Z / P+1) or Z / P, and the ratio of the number of card issuing coils with a span of (Z / P+1) to the number of card issuing coils with a span of Z / P is 1:3.

[0008] The hairpin coil span of any parallel branch from the i-th slot layer to the (i+1)-th slot layer is Z / P, and the welding span of any parallel branch from the i-th slot layer to the (i+1)-th slot layer is Z / P, i is a positive integer, and i <N。

[0009] The hairpin coil comprises a U-shaped hairpin coil and an I-shaped hairpin coil, wherein the U-shaped hairpin coil comprises a bent connecting section and two straight sections respectively inserted into two different stator slots and two welding sections protruding outward from the end surface of the stator core, wherein 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 welding sections is respectively connected to the other ends of the two straight sections; the bent connecting sections of all the U-shaped hairpin coils are all located at one end of the stator core to form a winding hairpin end, and the welding sections of all the U-shaped hairpin coils are all located at the other end of the stator core, and adjacent welding sections of adjacent U-shaped hairpin coils are welded together to form a winding welding end; The span is the number of stator slots spanned by two straight line segments of the U-shaped hairpin coil.

[0010] The voltage lead wire and neutral point lead wire of any phase stator winding are connected in star or triangle.

[0011] The present invention also provides a motor, comprising a stator and a rotor, wherein the stator is the above-mentioned stator.

[0012] The present invention also provides a vehicle, comprising the flat wire motor.

[0013] Compared with the prior art, the present invention has the following advantages and positive effects: 1. The stator of the present invention has three-phase stator windings symmetrically distributed along the circumferential direction of the stator core, and when any phase winding includes two parallel branches, the two parallel branches are also rotationally symmetrical in the circumferential direction of the stator core, so that the magnetic field distribution of multiple parallel branches in each phase winding is the same, the magnetic potential is balanced, the circulating current between the parallel branches is avoided, the efficiency of the flat wire motor is improved, and the local temperature rise of the winding is avoided, thereby extending the life of the flat wire motor; 2. Any parallel branch contains multiple hairpin coils with different spans. The multiple hairpin coils only contain two spans of Z / P and (Z / P+1). Z is the number of stator slots, P is the number of motor poles, and the hairpin coils with a span of (Z / P+1) are only located in the outermost or innermost layer of the stator slots. Only hairpin coils of the same phase stator winding exist in the same stator slot, which reduces the number of linear types of the hairpin coils and facilitates automated production. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0015] Figure 1 Schematic diagram of the three-dimensional structure of the stator of the flat wire motor in an embodiment of the present invention; Figure 2 Schematic diagram of the three-dimensional structure of the stator core of the stator in an embodiment of the present invention; Figure 3 Schematic diagram of slot layer distribution in stator slots of a stator in an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of a U-shaped hairpin coil in an embodiment of the present invention; Figure 5 The schematic diagram of a circuit in which three parallel branches of each phase winding in a three-phase stator winding of a stator in an embodiment of the present invention are connected in a star manner; Figure 6 It is a circuit diagram of two parallel branches of each phase winding in the three-phase stator winding of the stator assembly in an embodiment of the present invention connected in a triangle manner; Figure 7 It is an expanded view of the first parallel branch winding of the A-phase winding of the 8-pole 48-slot flat wire motor in the embodiment of the present invention; Figure 8 It is an expanded view of the second parallel branch winding of the A-phase winding of the 8-pole 48-slot flat wire motor in the embodiment of the present invention; Fig. 9 It is an expanded view of the A-phase winding of the 8-pole 48-slot flat wire motor in an embodiment of the present invention.

[0016] Figure numerals: 10, stator assembly; 11, stator core; 12, three-phase stator winding; 13, stator slot; 20, U-shaped hairpin coil; 21, bent connecting section; 22, straight section; 23, welding section. DETAILED DESCRIPTION

[0017] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0018] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0019] For ease of understanding, the professional terms appearing in this application are explained below.

[0020] Stator: refers to the stationary part of the motor, whose function is to generate a rotating magnetic field.

[0021] Rotor: refers to the rotating part in the motor, which is used to realize the conversion of electrical energy into mechanical energy.

[0022] An embodiment of the present invention provides a motor, the flat wire motor comprising a rotor and a stator 10, the rotor being arranged in a space enclosed by the inner wall of a stator core 11 of the stator 10. Figure 1 and Figure 2 As shown, the stator 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 arranged on the inner wall of the stator core 11 along the circumferential direction. Each stator slot 13 is evenly divided into N slot layers along the radial direction of the stator core 11. The three-phase stator winding 12 is symmetrically distributed along the circumferential direction of the stator core 11. Z and N are both positive integers.

[0023] As Figure 3As shown, each stator slot 13 is divided into 6 slot layers along the radial direction of the stator core 11, that is, N=6, that is, each stator slot 13 contains 6 layers of flat wire conductors, the first layer is recorded as D1, the second layer is recorded as D2, the third layer is recorded as D3, the fourth layer is recorded as D4, the fifth layer is recorded as D5, and the sixth layer is recorded as D6. The first slot layer is the slot bottom layer of the stator slot 13, and the sixth slot layer is the slot opening layer, or the first slot layer is the slot opening layer of the stator slot 13, and the sixth slot layer is the slot bottom layer.

[0024] Any one phase winding of the three-phase stator winding 12 (A phase winding, B phase winding and C phase winding) includes a parallel branches, a is 1 or 2, and 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 be rotationally symmetrical in the circumferential direction, the magnetic field distribution of the two parallel branches in each phase winding is made the same, the magnetic potential is balanced, and the circulating current between the parallel branches is avoided, thereby greatly reducing the additional AC copper loss under high-speed conditions, improving the efficiency of the flat wire motor, avoiding local temperature rise of the winding and overheating, and extending the life of the flat wire motor.

[0025] At the same time, any parallel branch contains multiple hairpin coils with different spans, and all hairpin coils have only two spans of Z / P and (Z / P+1), P is the number of motor poles, and any parallel branch has hairpin coils with two spans of Z / P and (Z / P+1), and the hairpin coils with a span of (Z / P+1) are only located in the outermost layer or the innermost layer of the stator slot 13; there are only hairpin coils of the same phase stator winding in the N slot layers in the same stator slot 13, which reduces the number of linear types of the hairpin coils, is conducive to simplifying the manufacturing process, reducing production costs, and facilitating automated production.

[0026] The card-isolating coils of each parallel branch include a U-shaped card-isolating coil 20 and an I-shaped card-isolating coil. The I-shaped card-isolating coil is the incoming and outgoing ends of each parallel branch. The U-shaped card-isolating coil 20 is located between the I-shaped card-isolating coils at both ends.

[0027] like Figure 4 As shown, the U-shaped hairpin coil 20 is formed by a flat wire conductor, the cross-section of the flat wire conductor is rectangular, including a bent connecting section 21, two straight sections 22 and two welding sections 23. The two straight sections 22 are used to be inserted into two different stator slots 13 respectively. The bent connecting section 21 and the welding section 23 both protrude from the outer side of the end surface 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 ends of the two welding sections 23 are respectively connected to the other ends of the two straight sections 22, thereby eliminating the potential phase difference caused by the positions of multiple parallel branches in each phase winding in the stator slot 13.

[0028] by Figure 4In the shown perspective, both ends of the bent connection section 21 are respectively connected to the tops of two straight sections 22, and the tops of two welding sections 23 are respectively connected to the bottoms of two straight sections 22. The bent connection sections 21 of all U-shaped hairpin coils 20 are all located at one end of the stator core 11 to form a winding wire insertion end, and the welding sections 23 of all U-shaped hairpin coils 20 are all located at the other end of the stator core 11. The adjacent welding sections 23 of adjacent U-shaped hairpin coils 20 are welded together to form a winding welding end. For example, the bottom end of the right welding section 23 of the left U-shaped hairpin coil 20 is welded to the bottom end of the left welding section 23 of the right U-shaped hairpin coil 20. The span refers to the number of stator slots 13 spanned by the two straight sections 22 of the U-shaped hairpin coil 20; the welding pitch between the hairpin coils is the number of stator slots spanned by the adjacent straight sections 22 of two adjacent hairpin coils.

[0029] The I-shaped hairpin coil is equivalent to half of the U-shaped hairpin coil 20. From Figure 4 the shown perspective, the I-shaped hairpin coil is equivalent to the left half or the right half of the U-shaped hairpin coil 20, and its structure will not be elaborated here.

[0030] In one embodiment, the U-shaped hairpin coil 20 can be inserted into the stator slot 13 and then bent to form the welding section 23. After the U-shaped hairpin coil 20 is inserted into the stator slot 13, its bent connection section 21 forms a winding wire insertion end, and the welding section 23 forms a winding welding end.

[0031] Furthermore, the voltage lead-out wires of a parallel branches are all located in the outermost layer or the innermost layer of the stator slot 13, and the neutral point lead-out wires of a parallel branches are all located in the outermost layer or the innermost layer of the stator slot 13, so as to facilitate the welding of the motor terminal and the bus bar and improve the motor production efficiency.

[0032] Furthermore, the span of the hairpin coils in the same layer of 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.

[0033] The span of the hairpin coils of any parallel branch from the i-th slot layer to the (i + 1)-th slot layer is Z / P, and the welding span of any parallel branch from the i-th slot layer to the (i + 1)-th slot layer is Z / P, where i is a positive integer and i < N, that is, the span of the non-same-layer hairpin coils and the non-same-layer welding span of any parallel branch are equal, so that the types of the U-shaped hairpin coil 20 are few and there is only one kind of welding span, which further facilitates welding and automated manufacturing.

[0034] The following embodiments take a flat wire motor with 8 poles P, 48 stator slots 13, 6 slot layers in each stator slot 13, and 2 parallel branches in each phase of the three-phase stator winding 12 as an example to explain in detail the winding structure of each phase winding of the stator of the present invention.

[0035] The U-shaped hairpin coil 20 of the stator 10 of this embodiment has only two spans, namely (Z / P+1) and Z / P, i.e., 7 and 6. The stator 10 is composed of a three-phase stator winding 12 (A-phase winding, B-phase winding and C-phase winding) with a phase difference of 120 electrical degrees, and the three-phase stator winding 12 is wound in the stator core 11.

[0036] The voltage lead wire and neutral point lead wire of any phase winding are connected in star or triangle, such as Figure 5 and Figure 6 shown.

[0037] Slot number i(j) represents the jth slot layer in the ith slot. For example, 2(1) below represents the 1st slot layer in the 2nd slot, referred to as the 2nd slot 1st slot layer. 8(2) represents the 2nd slot layer in the 8th slot, referred to as the 8th slot 2nd slot layer. The same applies to the other slot numbers below.

[0038] like Figure 7 As shown, the numbers 1 to 48 arranged horizontally represent the slot numbers, which are arranged in a circle in a ring. Figure 2 As shown; the 6 real and virtual vertical lines corresponding to each number from 1 to 48 represent slot layers 1 to 6, with a total of 6 slot layers. A1 and A2 can be used as voltage lead wires or as neutral point lead wires, and correspondingly, X1 and X2 can be used as voltage lead wires or as neutral point lead wires. For example, A1 is used as the voltage lead wire of the first parallel branch of phase A, and X1 is used as the neutral point lead wire of the first parallel branch of phase A; A2 is used as the voltage lead wire of the second parallel branch of phase A, and X2 is used as the neutral point lead wire of the second parallel branch of phase A.

[0039] Similarly, B1 and B2 can be used as the voltage lead-out wires of phase B and as the neutral point lead-out wires. Correspondingly, Y1 and Y2 can be used as the voltage lead-out wires and as the neutral point lead-out wires. For example, B1 is used as the voltage lead-out wire of the first parallel branch of phase B, and Y1 is used as the neutral point lead-out wire of the first parallel branch of phase B; B2 is used as the voltage lead-out wire of the second parallel branch of phase B, and Y2 is used as the neutral point lead-out wire of the second parallel branch of phase B.

[0040] C1 and C2 can be used as the voltage lead-out wires of phase C and also as the neutral point lead-out wires. Correspondingly, Z1 and Z2 can be used as the voltage lead-out wires and also as the neutral point lead-out wires. For example, C1 is used as the voltage lead-out wire of the first parallel branch of phase C, and Z1 is used as the neutral point lead-out wire of the first parallel branch of phase C; C2 is used as the voltage lead-out wire of the second parallel branch of phase C, and Z2 is used as the neutral point lead-out wire of the second parallel branch of phase C.

[0041] like Figure 7 As shown, the first parallel branch of phase A goes in from the first slot level of the second slot, and finally goes out from the sixth slot level of the seventh slot to the center point of the three phases. The slot numbers through which the first parallel branch is connected in series are: 2(1)-8(2)-14(1)-20(2)-26(1)-32(2)-38(1)-44(2)-2(3)-8(4)-14(3)-20(4)-26(3)-32(4)-38(3)-44(4)-2(5)-8(6)-14(5)-20(6)-26(5)-32(6)-38(5)-44(6 )-37(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).

[0042] like Figure 8 As shown, the second parallel branch of phase A goes in from the 6th slot level of the 2nd slot, and finally goes out from the 1st slot level of the 31st slot to the center point of the three phases. The slot numbers through which the second parallel branch is connected in series are: 2(6)-44(5)-38(6)-32(5)-26(6)-20(5)-14(6)-8(5)-2(4)-44(3)-38(4)-32(3)-26(4)-20(3)-14(4)-8(3)-2(2)-44(1)-38(2)-32(1)-26(2)-20(1)-14(2)-8(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).

[0043] The starting slot number and the ending slot number corresponding to the two parallel branch windings are distributed as follows: A1 corresponds to 2 (1), X1 corresponds to 7 (6); A2 corresponds to 2 (6), X2 corresponds to 31 (1); the span of the cross-layer hairpin coils of the two branch windings is 6, the two branch winding coils have the same span, the same resistance value, and are completely symmetrical around the circumference, and there is no potential difference to cause branch circulation. The span of the hairpin coils on the same layer is 6 or 7, and the ratio of the number of hairpin coils with a span of 7 to the number of hairpin coils with a span of 6 is 1:3. The span of the hairpin coils at the welding end is 6, that is, the welding span is 6, which is convenient for welding and automated production.

[0044] The A-phase winding, the B-phase winding and the C-phase winding are symmetrically and evenly distributed on the circumference of the stator core 11 , and the winding method of the B-phase winding and the C-phase winding will not be described in detail here.

[0045] This embodiment also proposes a vehicle, including the above-mentioned motor, which will not be described in detail here.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A stator, characterized in that: include: A stator core, the inner wall of which is uniformly provided with Z stator slots along the circumferential direction, each of the stator slots being divided into N slot layers along the radial direction of the stator core; A three-phase stator winding is wound in the stator core and symmetrically distributed along the circumference of the stator core; any one phase of the three-phase stator winding includes a parallel branches, a is 1 or 2, and when a is 2, the two parallel branches are rotationally symmetrical in the circumferential direction of the stator core; any one parallel branch contains a plurality of hairpin coils with different spans, and the hairpin coils only contain two spans of Z / P and (Z / P+1), and P is the number of motor poles; any one parallel branch has hairpin coils with two spans of Z / P and (Z / P+1), and the hairpin coil with a span of (Z / P+1) is only located in the outermost layer or the innermost layer of the stator slot; only hairpin coils of the same phase stator winding exist in the N slot layers of the same stator slot.

2. The stator according to claim 1, characterized in that: The voltage lead wires of the a parallel branches are all located at the outermost layer or the innermost layer of the stator slots, and the neutral point lead wires of the a parallel branches are all located at the outermost layer or the innermost layer of the stator slots.

3. The stator according to claim 1, characterized in that: The span of the card issuing coils of the same layer in the outermost or innermost layer of any parallel branch is (Z / P+1) or Z / P, and the ratio of the number of card issuing coils with a span of (Z / P+1) to the number of card issuing coils with a span of Z / P is 1:

3.

4. The stator according to any one of claims 1 to 3, characterized in that: The hairpin coil span of any parallel branch from the i-th slot layer to the (i+1)-th slot layer is Z / P, and the welding span of any parallel branch from the i-th slot layer to the (i+1)-th slot layer is Z / P, i is a positive integer, and i <N。 5. The stator according to claim 1, characterized in that: The hairpin coil comprises a U-shaped hairpin coil and an I-shaped hairpin coil, wherein the U-shaped hairpin coil comprises a bent connecting section and two straight sections respectively inserted into two different stator slots and two welding sections protruding outward from the end surface of the stator core, wherein 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 welding sections is respectively connected to the other ends of the two straight sections; the bent connecting sections of all the U-shaped hairpin coils are all located at one end of the stator core to form a winding hairpin end, and the welding sections of all the U-shaped hairpin coils are all located at the other end of the stator core, and adjacent welding sections of adjacent U-shaped hairpin coils are welded together to form a winding welding end; The span is the number of stator slots spanned by two straight line segments of the U-shaped hairpin coil.

6. A stator according to claim 1, characterized in that: The voltage lead wire and neutral point lead wire of any phase stator winding are connected in star or triangle.

7. A motor, comprising a stator and a rotor, characterized in that: The stator is the stator according to any one of claims 1 to 6.

8. A vehicle, characterized in that: Comprising the motor as claimed in claim 7.

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