A low harmonic flat wire stator and motor

Abstract

The present invention provides a low harmonic flat wire stator and motor, including a stator core and a flat wire winding; the inner wall of the stator core is evenly provided with 12m stator slots along the circumferential direction, the stator slots are divided into 2n layers along the radial direction of the core, and the flat wire winding is wound in the stator slots; the flat wire winding includes two sets of three-phase windings, which are 30 degrees electrical angle apart in space, and the flat wire windings are arranged symmetrically in double short distances in the stator slots; each phase winding includes at least one parallel branch, each parallel branch includes a plurality of flat wire coils connected in series, each of the flat wire coils includes a forming end and two welding ends, and the two welding ends are respectively inserted into the 2i and 2i-1 layers of the stator slots, 1≤i≤n. While maintaining a small number of line types, the electrical balance of the motor, the balance of the number of winding layers, the low harmonic content, the high torque density, the small span of the cross-line end and the welding end, the high efficiency, the strong fault tolerance, and the connection scheme of the flat wire winding that is universal for different voltage platforms are achieved.

Description

Technical Field

[0001] The present application belongs to the technical field of motors, and specifically relates to a low-harmonic flat wire stator and a motor. Background Art

[0002] Most existing drive motors are three-phase motors. Compared with three-phase motors, multi-phase motors have the advantages of high torque density, small torque pulsation and strong fault tolerance. Dual three-phase motors are a type of multi-phase motor that is used more frequently. They are composed of two sets of independent three-phase windings. These two sets of windings are powered by two independent three-phase inverters, which are 30 degrees electrical angle apart in space. They eliminate 6th, 18th, 30th, and 42nd order torque pulsations and radial electromagnetic force density, and improve the fundamental winding factor. Therefore, the overall stability of the motor is improved while the torque density is also improved.

[0003] At the same time, in order to improve the torque density and power density of the motor, placing flat wire windings, i.e. rectangular conductors, in the stator slots of the motor stator core can greatly increase the slot fill rate of the motor stator winding, save volume, thereby reducing the copper loss of the motor and providing better acceleration performance.

[0004] Since multi-phase motors have more phases than ordinary three-phase motors, the winding method is more complicated, and there are many combinations of the number of flat wire winding layers and the number of parallel branches. It is difficult to find a flat wire winding connection solution with fewer line types, electrical balance, balanced number of winding layers and strong versatility. Summary of the invention

[0005] The present application aims to provide a low-harmonic flat wire stator and motor, which can achieve motor electrical balance, winding layer balance and a flat wire winding connection solution that is universal for different voltage platforms while maintaining a small number of wire types. At the same time, it can reduce the equipment investment ratio and improve the utilization rate of equipment and motors, thereby achieving the goal of comprehensive cost reduction.

[0006] In a first aspect, an embodiment of the present application provides a low harmonic flat wire stator, comprising a stator core and a flat wire winding; the inner wall of the stator core is evenly provided with 12m stator slots along the circumferential direction, the stator slots are divided into 2n layers along the radial direction of the stator core, and the flat wire winding is wound in the stator slots;

[0007] The flat wire winding includes two sets of three-phase windings, which are 30 degrees electrical angle apart in space, and the flat wire windings are arranged symmetrically in double short pitches in the stator slots;

[0008] Each phase winding includes at least one parallel branch, each parallel branch includes a plurality of flat wire coils connected in series, each of the flat wire coils includes a formed end and two welding ends, the two welding ends are respectively inserted into the 2i and 2i-1 layers of the stator slots, 1≤i≤n, wherein m, n, i are all positive integers.

[0009] Optionally, the pole pitch of the flat wire winding is p, and the spans of the forming end and the welding end of the flat wire coil are equal and are both p-1, wherein p≥6, and p is a positive integer.

[0010] Optionally, the input end of each of the parallel branches is located at the jth slot of the 2n layer, inserted into the j+p-1th slot of the 2n-1 layer with a span of p-1, and then inserted into the jth slot of the 2n-2 layer with a span of p-1, and is wound in descending order between the jth slot and the j+p-1th slot layer by layer until it reaches the j+p-1th slot of the 1st layer, where 1≤j≤12m and j is a positive integer.

[0011] Optionally, the output end of each of the parallel branches is located at the 2nth layer, and the parallel branches are inserted from the 1st layer to the 2nd layer with a span of p-1, and then inserted into the 3rd layer with a span of p-1, and are wound in ascending order layer by layer between the two stator slots until they reach the 2nth layer.

[0012] Optionally, when the flat wire winding is commutated at the first layer, the welding ends of two adjacent flat wire coils are welded and connected, spanning p-1 or p+1 stator slots; when the flat wire winding is commutated at the 2n layer, the welding ends of two adjacent flat wire coils are welded and connected, spanning p stator slots.

[0013] Optionally, the inner wall of the stator core is evenly provided with 72 stator slots along the circumferential direction, the stator slots are divided into 6 layers along the radial direction of the core, the pole pitch is 12, the flat wire winding includes two sets of three-phase windings of U, V, W and U', V', W', and each phase winding includes 6 branches;

[0014] The winding method of the first branch of the U-phase winding, i.e., the U1 branch, is: the 6th layer of the 1st slot, the 5th layer of the 12th slot, the 4th layer of the 1st slot, the 3rd layer of the 12th slot, the 2nd layer of the 1st slot, the 1st layer of the 12th slot, the 1st layer of the 25th slot, the 2nd layer of the 14th slot, the 3rd layer of the 25th slot, the 4th layer of the 14th slot, the 5th layer of the 25th slot, and the 6th layer of the 14th slot;

[0015] The winding method of the first branch of the U'-phase winding, i.e., the U1' branch, is: the 6th layer of the 3rd slot, the 5th layer of the 14th slot, the 4th layer of the 3rd slot, the 3rd layer of the 14th slot, the 2nd layer of the 3rd slot, the 1st layer of the 14th slot, the 1st layer of the 27th slot, the 2nd layer of the 16th slot, the 3rd layer of the 27th slot, the 4th layer of the 16th slot, the 5th layer of the 27th slot, and the 6th layer of the 16th slot.

[0016] Optionally, U2 branch and U2' branch are obtained by offsetting the U1 branch and the U1' branch by one stator slot to constitute a first winding unit; the second winding unit includes U3, U3', U4, and U4' branches, which are obtained by offsetting the first winding unit by 24 stator slots; and the third winding unit includes U5, U5', U6, and U6' branches, which are obtained by offsetting the first winding unit by 48 stator slots.

[0017] Optionally, the flat wire winding is commutated once in the first layer, and the welding ends of two adjacent flat wire coils are welded and connected. In the U1 branch and the U1' branch, the two adjacent flat wire coils in the first layer span 13 stator slots; in the U2 branch and the U2' branch, the two adjacent flat wire coils in the first layer span 11 stator slots.

[0018] Optionally, the V, V'-phase windings and the W, W'-phase windings are obtained by arraying the U, U'-phase windings at electrical angles of 120 degrees and 240 degrees, respectively, in the circumferential direction.

[0019] In a second aspect, the present application provides a motor, comprising at least any low-harmonic flat wire stator as described in the first aspect.

[0020] Compared with the prior art, this application has the following advantages:

[0021] Two sets of independent three-phase windings are used, and the flat wire windings are arranged symmetrically with short distances. Only m types of wires are needed for the 2m-layer stator slots. The two sets of windings are 30 degrees electrical angle apart in space, with a phase difference of 180° and the amplitude remains unchanged. Harmonics of specific orders can be eliminated, and the 6th, 18th, 30th, and 42nd order torque pulsations and radial electromagnetic force density are eliminated. At the same time, the fundamental winding factor is improved, thereby improving the overall stability of the motor and the torque density. While maintaining fewer wire types, the motor electrical balance, winding layer balance, low harmonic content, high torque density, small span between the cross-line end and the welding end, high efficiency, strong fault tolerance, and a flat wire winding connection solution that is universal for different voltage platforms can be achieved. At the same time, the equipment investment ratio can be reduced and the utilization rate of equipment and motors can be improved, achieving the purpose of comprehensive cost reduction while meeting performance requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0023] Figure 1 is a cross-sectional view of a 72-slot 6-pole motor according to an embodiment of the present invention;

[0024] Figure 2 is a 3D diagram of a 72-slot 6-pole motor according to an embodiment of the present invention;

[0025] Figure 3 The numbers of the flat wires of each layer are arranged from the notch to the bottom of the notch according to an embodiment of the present invention;

[0026] Figure 4 is a schematic diagram of a 72-slot, 6-pole, 6-layer, 6-branch winding according to an embodiment of the present invention;

[0027] Figure 5 is a schematic diagram of a 72-slot, 6-pole, 6-layer, 3-branch winding according to an embodiment of the present invention;

[0028] Figure 6 is a schematic diagram of a 72-slot, 6-pole, 6-layer, 2-branch winding according to an embodiment of the present invention;

[0029] Figure 7 is a schematic diagram of a 72-slot, 6-pole, 6-layer, 1-branch winding according to an embodiment of the present invention;

[0030] Figure 8 is a schematic diagram of a 96-slot, 8-pole, 8-layer, 8-branch winding according to an embodiment of the present invention;

[0031] Fig. 9 is a schematic diagram of a 96-slot, 8-pole, 8-layer, 4-branch winding according to an embodiment of the present invention;

[0032] Fig.10 is a schematic diagram of a 96-slot, 8-pole, 8-layer, 2-branch winding according to an embodiment of the present invention;

[0033] Fig.11 is a schematic diagram of a 96-slot, 8-pole, 8-layer, 1-branch winding according to an embodiment of the present invention;

[0034] Fig.12 is a schematic diagram of a 48-slot, 8-pole, 8-layer, 4-branch winding according to an embodiment of the present invention;

[0035] Fig.13 is a schematic diagram of a 48-slot, 8-pole, 8-layer, 2-branch winding according to an embodiment of the present invention;

[0036] Fig.14 is a schematic diagram of a 48-slot, 8-pole, 8-layer, 1-branch winding according to an embodiment of the present invention;

[0037] Fig.15 yes Figure 4 The enlarged view of the circled part a;

[0038] Fig.16 yes Figure 5 An enlarged view of the circled portion b;

[0039] Fig.17 yes Figure 6 An enlarged view of the circled portion c;

[0040] Fig.18 yes Figure 7 An enlarged view of the circled portion d;

[0041] Fig.19 yes Figure 8 An enlarged view of the circled portion e;

[0042] Fig. 20 yes Fig. 9 The enlarged view of the circled part f;

[0043] Fig.21 yes Fig.10 The enlarged view of the circled portion g;

[0044] Fig. 22 yes Fig.11 The enlarged view of the h part circled in the middle;

[0045] Fig.23 yes Fig.12 An enlarged view of the circled portion i;

[0046] Fig.24 yes Fig.13 An enlarged view of the circled portion j;

[0047] Fig.25 yes Fig.14 Magnified view of the circled k portion.

[0048] Figure numerals: 1: stator core; 2: flat wire winding; 3: stator slot; 4: copper bar. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the fixed scope of the present invention.

[0050] It should be understood that the references to "one embodiment" or "an embodiment" throughout the specification mean that the specific features, structures, or characteristics associated with the embodiment are included in at least one embodiment of the present invention. Therefore, the references to "in one embodiment" or "in an embodiment" appearing throughout the specification do not necessarily refer to the same embodiment. In addition, these specific features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0051] See also Figure 1 and Figure 2As shown, the low harmonic flat wire stator includes: a stator core 1 and a flat wire winding 2; the inner wall of the stator core 1 is evenly provided with 12m stator slots 3 along the circumferential direction, the stator slots 3 are divided into 2n layers along the radial direction of the stator core 1, and the flat wire winding 2 is wound in the stator slots 3; the flat wire winding 2 includes two sets of three-phase windings, which are 30 degrees electrical angle apart in space, and the flat wire winding 2 is symmetrically arranged in double short distances in the stator slot 3; each phase winding includes at least one parallel branch, each parallel branch includes a plurality of flat wire coils connected in series, each flat wire coil includes a formed end and two welding ends, and the two welding ends are respectively inserted into the 2i and 2i-1 layers of the stator slot 3, 1≤i≤n, wherein m, n, i are all positive integers.

[0052] In the embodiment of the present application, the flat wire winding 2 includes two sets of symmetrical three-phase windings of U, V, W and U', V', W', which are 30 degrees electrical angle apart in space. There are 6 phases in total, and each phase has at least 2 magnetic poles. It is suitable for a double three-phase motor with a stator slot number that is a multiple of 12 and a stator slot 3 divided into an even number of layers. Therefore, the number of stator slots is defined as 12m and the number of layers is 2n. The number of poles of the motor, the number of slots occupied by each pole and each phase, and the number of branches included in each phase winding can be determined according to actual conditions. When each phase winding includes two or more branch windings, the two or more branch windings in each phase winding are connected in parallel, and the lead wires at the output end can be directly connected in parallel or led out through the lead copper bus 4.

[0053] Most of the existing new energy drive motors are three-phase motors. Compared with three-phase motors, multi-phase motors have the advantages of high torque density, small torque pulsation and strong fault tolerance. The windings of the dual three-phase motor are composed of two sets of independent three-phase windings, which are powered by two independent three-phase inverters, so they have the advantage of strong fault tolerance. The dual three-phase motor windings in this application are composed of two sets of three-phase symmetrical windings connected in star or triangle. The two sets of windings are 30 degrees electrical angle apart in space, with a phase difference of 180°, and the amplitude remains unchanged, which can eliminate harmonics of specific orders, eliminate 6th, 18th, 30th, and 42nd order torque pulsations and radial electromagnetic force density, and at the same time improve the fundamental winding factor, thereby improving the overall stability of the motor while also improving the torque density.

[0054] like Figure 4-Figure 14 As shown, they are the winding schematic diagrams of a 72-slot 6-pole 6-layer motor, a 96-slot 8-pole 8-layer motor, and a 48-slot 8-pole 8-layer motor. Figure 15-Figure 25It is a partial enlarged diagram of the schematic diagram of the above three electrode windings. The solid line is the formed end of the flat wire coil, and the dotted line is the welding end. The flat wire winding 2 is arranged symmetrically with double short pitch, and the pole pitch is p, p ≥ 6, and p is a positive integer. The flat wire coils in the winding are arranged across the layers in the two adjacent layers of the stator slots 3, with a spacing of p-1 stator slots 3. The pitch refers to the number of slots spanned between the two element sides of each coil of the motor winding, also known as the span. The value of the pitch is expressed in the number of slots. The span of the flat wire coils in the embodiments of the present application is p-1. The welding ends of the two adjacent flat wire coils in the branch are welded and connected so that the two flat wire coils are connected in series, and the span of the two welding ends is also p-1. Then all the flat wire coils have the same span of p-1, which is a double short pitch arrangement. Only coils of the same linear type need to be used in every two layers, and a total of m linear types are required for 2m layers.

[0055] Each parallel branch includes an input terminal and an output terminal, which are represented by + and - respectively. Both the input terminal and the output terminal are located at the 2nth layer. The stator slots 3 distributed along the circumference of the stator core 1 are numbered in sequence. The input terminal is located at the jth slot of the 2nth layer, 1≤j≤12m, j is a positive integer, and is inserted into the j+p-1th slot of the 2n-1th layer with a span of p-1, and then inserted into the jth slot of the 2n-2th layer with a span of p-1. It is wound in descending order layer by layer between the jth slot and the j+p-1th slot until it reaches the j+p-1th slot of the 1st layer. The output terminal is located at the 2nth layer. The parallel branch is inserted from the 1st layer to the 2nd layer with a span of p-1, and then inserted into the 3rd layer with a span of p-1. It is wound in ascending order layer by layer between two stator slots 3 until it reaches the 2nth layer.

[0056] The flat wire winding 2 is wound in descending order from the 2nth layer to the 1st layer, reverses at the 1st layer, and reversely winds the 2nth layer. In some embodiments, the number of times the flat wire winding 2 is wound in a cycle is appropriately changed according to actual conditions. The flat wire winding 2 can be reversed again at the 2nth layer, and the above winding process is repeated again, and finally output from the 2nth layer. When the 1st layer is reversed, the welding ends of two adjacent flat wire coils inserted into the 1st layer of the stator slot 3 are welded and connected, and the two welding ends span p-1 or p+1 stator slots 3; when the flat wire winding 2 is reversed at the 2nth layer, the welding ends of two adjacent flat wire coils are welded and connected, and the two welding ends span p stator slots 3.

[0057] It can be understood that the first layer in the present application can be a layer close to the outer wall of the stator core 1, and the 2nth layer is close to the inner wall of the stator core 1; or vice versa, the first layer is close to the inner wall of the stator core 1, and the 2nth layer is close to the outer wall of the stator core 1. The exchange of the inner and outer layers does not affect the characteristics and performance of the flat wire stator in the present application.

[0058] The winding scheme proposed in the present application has the same pitch for all coils, and the flat wire coils are arranged in cross-layers in the stator slots 3. Only coils of the same wire type need to be used in every two layers, and a total of m wire types are required for 2m layers. While keeping the number of wire types small, the electrical balance of the motor, the balance of the number of winding layers, the low harmonic content, the high torque density, the small span between the cross-wire end and the welding end, the high efficiency, the strong fault tolerance, and the connection scheme of the flat wire winding 2 that is universal for different voltage platforms can be achieved. At the same time, the equipment investment ratio can be reduced and the utilization rate of equipment and motors can be improved, so as to achieve the goal of comprehensive cost reduction while meeting the performance.

[0059] like Figure 1-Figure 7 As shown, firstly, the low harmonic flat wire stator disclosed in the present application is introduced by taking a 72-slot 6-pole 6-layer motor as an example. In the embodiment of the present application, the number of stator slots occupied by each pole and each phase is 2, and there are 6 poles and 6 phases in total. Then, the stator slot 3 is provided with 72 stator slots 3 along the circumferential direction, m=6, n=3, p=12, and the double three-phase flat wire winding 2 is symmetrically arranged in the stator slot 3 with a span of 11 and double short distance.

[0060] The embodiments in the present application are for illustration only, and the flat wire winding 2 wound according to the same principle can be applied to dual three-phase motor stators with different numbers of poles, layers and slots.

[0061] Embodiment 1

[0062] like Figure 4 As shown, the 72-slot 6-pole 6-layer motor in the embodiment of the present application has 6 branches per phase winding, the solid line is the formed end of the flat wire coil, and the dotted line is the welding end. For the sake of clarity, the schematic diagram only shows the connection relationship of the U and U' phase windings. The V, V' phase and W, W' phase windings can be obtained by the U and U' phase windings with an electrical angle array of 120 degrees and 240 degrees respectively in the circumferential direction. The digital labels in U numbers and U numbers' represent the number of branches, and no' and yes' represent the first set of windings and the second set of windings of the dual three-phase respectively; for example, the digital labels of U and U' such as U1 and U1' represent the first branch of the first set of windings of the U phase and the first branch of the second set of windings of the U phase respectively.

[0063] The winding method of U1 branch is: 6th layer in the 1st slot, 5th layer in the 12th slot, 4th layer in the 1st slot, 3rd layer in the 12th slot, 2nd layer in the 1st slot, 1st layer in the 12th slot, 1st layer in the 25th slot, 2nd layer in the 14th slot, 3rd layer in the 25th slot, 4th layer in the 14th slot, 5th layer in the 25th slot, and 6th layer in the 14th slot.

[0064] The winding method of U1' branch is: 6th layer in the 3rd slot, 5th layer in the 14th slot, 4th layer in the 3rd slot, 3rd layer in the 14th slot, 2nd layer in the 3rd slot, 1st layer in the 14th slot, 1st layer in the 27th slot, 2nd layer in the 16th slot, 3rd layer in the 27th slot, 4th layer in the 16th slot, 5th layer in the 27th slot, and 6th layer in the 16th slot.

[0065] That is, each branch is first arranged from the 6th layer located at the outermost layer of the stator slot 3, and a coil is arranged from the 6th layer to the 5th layer according to a span of 11, and the second coil is arranged at the same position from the 4th layer to the 3rd layer, and the third coil is arranged at the same position from the 2nd layer to the 1st layer. The first direction is reversed in the first layer, and the first direction is consistent with the forward direction of the branch, and it is arranged in reverse from the 1st layer to the 6th layer.

[0066] The flat wire winding 2 is commutated once in the first layer, and the welding ends of two adjacent flat wire coils are welded and connected. In the U1 branch and the U1' branch, the two adjacent flat wire coils in the first layer span 13 stator slots 3; in the U2 branch and the U2' branch, the two adjacent flat wire coils in the first layer span 11 stator slots 3.

[0067] Specifically, when the previous coil is located in the even-numbered slots of the first layer, the next coil is inserted across 13 stator slots 3 along the first direction; when the previous coil is located in the odd-numbered slots of the first layer, the next coil is inserted across 11 stator slots 3 along the first direction, so that each branch is uniformly symmetrical and the potential of each branch is balanced.

[0068] In this embodiment, the motor pole pitch is 12, and the flat wire coils are arranged in two adjacent layers of the stator slots 3. The two ends of the formed ends of the flat wire coils are separated by 11 stator slots 3, that is, the span of the flat wire winding 2 in this embodiment is 11. The welding ends of the two adjacent flat wire coils in the branch are welded and connected, so that the two flat wire coils are connected in series, and the span of the two welding ends is also 11, that is, double short-distance symmetrical arrangement. All the flat wire coils in the stator slots 3 have the same span of 11, and only coils of the same linear type need to be used in every two layers of stator slots 3, and a total of 3 linear types are required for 6 layers.

[0069] The flat wire winding 2 in this embodiment is arranged in a clockwise direction. When the winding direction is opposite, the flat wire winding 2 arranged according to the above principle is still applicable, and the starting position can be any stator slot 3 .

[0070] The U2 branch and the U2' branch are obtained by offsetting the U1 branch and the U1' branch by one stator slot 3, forming a first winding unit. The second winding unit includes the U3, U3', U4, and U4' branches, which are obtained by offsetting the first winding unit by 24 stator slots 3. The third winding unit includes the U5, U5', U6, and U6' branches, which are obtained by offsetting the first winding unit by 48 stator slots 3.

[0071] The V, V' phase and W, W' phase windings are obtained by circumferentially spacing the U, U' phase windings at 120 degrees and 240 degrees electrical angle arrays respectively. Each phase winding is evenly and symmetrically distributed, with balanced winding layers, low harmonic content, high torque density, small span between the line end and the welding end, high efficiency and strong fault tolerance.

[0072] Furthermore, if Figure 2As shown, in the embodiment of the present application, the stator slots 3 are defined as the 1st to 6th layers from the inner wall to the outer wall of the stator core 1, and the input and output ends of each parallel branch are located at the 6th layer close to the outer wall of the stator core 1, such as the U1 branch, which inputs from the 6th layer of the 1st slot and outputs from the 6th layer of the 14th slot. The input and output ends of each branch are located on the same side of the stator slot 3, which is convenient for the lead wire to be connected to the copper bus 4, so that the soldering points are concentrated and the copper bus 4 has a simple structure.

[0073] It can be understood that the flat wire winding 2 can also be arranged starting from the first layer, in which case the input end and the output end of each parallel branch are both located in the first layer close to the inner wall of the stator core 1 .

[0074] In some optional embodiments, the number of stator slots can be 2 layers, 4 layers, or 8 layers. The winding method of the above-mentioned 6-layer motor can be referred to, and the winding method in the embodiment of the present application is still applicable after appropriate adjustment.

[0075] Embodiment 2

[0076] like Figure 5 As shown, the 72-slot, 6-pole, 6-layer motor in the embodiment of the present application has 3 branches per phase winding, the solid line is the formed end of the flat wire coil, and the dotted line is the welding end. For clarity, the schematic diagram only shows the connection relationship between the U and U' phase windings. The V, V' phase and W, W' phase windings can be obtained by the U and U' phase windings with an electrical angle array of 120 degrees and 240 degrees respectively spaced along the circumferential direction. The digital labels in the U numbers and U numbers' represent the number of branches, and the absence of 'and the presence of 'represent the first set of windings and the second set of windings of the dual three-phase, respectively; for example, the digital labels of U and U', such as U1 and U1', represent the first branch of the first set of windings of the U phase and the first branch of the second set of windings of the U phase, respectively. The first set of windings of the U phase includes three branches, U1, U2, and U3, and the second set of windings of the U phase includes three branches, U1', U2', and U3'.

[0077] The winding method of U1 branch is: 6th layer in the 1st slot, 5th layer in the 12th slot, 4th layer in the 1st slot, 3rd layer in the 12th slot, 2nd layer in the 1st slot, 1st layer in the 12th slot, 1st layer in the 25th slot, 2nd layer in the 14th slot, 3rd layer in the 25th slot, 4th layer in the 14th slot, 5th layer in the 25th slot, 6th layer in the 14th slot, 6th layer in the 2nd slot, 5th layer in the 13th slot, 4th layer in the 2nd slot, 3rd layer in the 13th slot, 2nd layer in the 2nd slot, 1st layer in the 13th slot, 1st layer in the 24th slot, 2nd layer in the 13th slot, 3rd layer in the 24th slot, 4th layer in the 13th slot, 5th layer in the 24th slot, 6th layer in the 13th slot.

[0078] The winding method of U1' branch is: the 6th layer of the 3rd slot, the 5th layer of the 14th slot, the 4th layer of the 3rd slot, the 3rd layer of the 14th slot, the 2nd layer of the 3rd slot, the 1st layer of the 14th slot, the 1st layer of the 27th slot, the 2nd layer of the 16th slot, the 3rd layer of the 27th slot, the 4th layer of the 16th slot, the 5th layer of the 27th slot, the 6th layer of the 16th slot, the 6th layer of the 4th slot, the 5th layer of the 15th slot, the 4th layer of the 4th slot, the 3rd layer of the 15th slot, the 2nd layer of the 4th slot, the 1st layer of the 15th slot, the 1st layer of the 26th slot, the 2nd layer of the 15th slot, the 3rd layer of the 26th slot, the 4th layer of the 15th slot, the 5th layer of the 26th slot, and the 6th layer of the 15th slot.

[0079] That is, each branch is first arranged from the 6th layer located at the outermost layer of the stator slot 3, and a coil is arranged from the 6th layer to the 5th layer according to the span of 11, and the second coil is arranged at the same position from the 4th layer to the 3rd layer, and the third coil is arranged at the same position from the 2nd layer to the 1st layer, and the first layer is commutated along the first direction, and arranged from the 1st layer to the 6th layer in the reverse direction. The second commutation is performed in the 6th layer along the second direction, and the second direction is opposite to the first direction, and the above process of winding from the 6th layer to the 1st layer and then winding from the 1st layer to the 6th layer is repeated.

[0080] The flat wire winding 2 is commutated twice in the first layer, and the welding ends of two adjacent flat wire coils are welded and connected. In the first commutation, the two adjacent flat wire coils in the first layer span 13 stator slots 3; in the second commutation, the two adjacent flat wire coils in the first layer span 11 stator slots 3. Commutation is performed once in the sixth layer, and the two adjacent flat wire coils span 12 stator slots 3.

[0081] Specifically, when the previous coil is located in the even-numbered slots of the first layer, the next coil is inserted across 13 stator slots 3 along the first direction; when the previous coil is located in the odd-numbered slots of the first layer, the next coil is inserted across 11 stator slots 3 along the first direction; when the previous coil is located in the sixth layer, the next coil is inserted across 12 stator slots 3 along the second direction. This ensures that each branch is evenly and symmetrically arranged and the potential of each branch is balanced.

[0082] The U2 branch and the U2' branch are obtained by offsetting the U1 branch and the U1' branch by 24 stator slots 3, and the U3 branch and the U3' branch are obtained by offsetting the U1 branch and the U1' branch by 48 stator slots 3.

[0083] The V, V' phase and W, W' phase windings are obtained by circumferentially spacing the U, U' phase windings at 120 degrees and 240 degrees electrical angle arrays respectively. Each phase winding is evenly and symmetrically distributed, with balanced winding layers, low harmonic content, high torque density, small span between the line end and the welding end, high efficiency and strong fault tolerance.

[0084] Compared with the winding method with 6 branches, the basic principle of winding is the same, the position of the stator slot 3 of the coil arrangement, the span and the number of coils of the entire flat wire stator are also the same. Only when the number of branches is different, the length of each branch, the number of coils and the input and output positions are adjusted to match the number of stator slots.

[0085] Embodiment 3

[0086] like Figure 6 As shown, the 72-slot 6-pole 6-layer motor in the embodiment of the present application has 2 branches per phase winding, the solid line is the formed end of the flat wire coil, and the dotted line is the welding end. The digital labels of U and U', such as U1 and U1', represent the first branch of the first set of windings of the U phase and the first branch of the second set of windings of the U phase, respectively. The first set of windings of the U phase includes two branches, U1 and U2, and the second set of windings of the U phase includes two branches, U1' and U2'.

[0087] The winding method of U1 branch is: 6th layer of the 1st slot, 5th layer of the 12th slot, 4th layer of the 1st slot, 3rd layer of the 12th slot, 2nd layer of the 1st slot, 1st layer of the 12th slot, 1st layer of the 25th slot, 2nd layer of the 14th slot, 3rd layer of the 25th slot, 4th layer of the 14th slot, 5th layer of the 25th slot, 6th layer of the 14th slot, 6th layer of the 26th slot, 5th layer of the 37th slot, 4th layer of the 26th slot, 3rd layer of the 37th slot, 2nd layer of the 26th slot, 4th layer of the 37th slot Slot 7, 1st layer, slot 48, 1st layer, slot 37, 2nd layer, slot 48, 3rd layer, slot 37, 4th layer, slot 48, 5th layer, slot 37, 6th layer, slot 49, 6th layer, slot 60, 5th layer, slot 49, 4th layer, slot 60, 3rd layer, slot 49, 2nd layer, slot 60, 1st layer, slot 1, 1st layer, slot 62, 2nd layer, slot 1, 3rd layer, slot 62, 4th layer, slot 1, 5th layer, slot 62, 6th layer.

[0088] The winding method of U1' branch is: 6th layer of the 3rd slot, 5th layer of the 14th slot, 4th layer of the 3rd slot, 3rd layer of the 14th slot, 2nd layer of the 3rd slot, 1st layer of the 14th slot, 1st layer of the 27th slot, 2nd layer of the 16th slot, 3rd layer of the 27th slot, 4th layer of the 16th slot, 5th layer of the 27th slot, 6th layer of the 16th slot, 6th layer of the 28th slot, 5th layer of the 39th slot, 4th layer of the 28th slot, 3rd layer of the 39th slot, 2nd layer of the 28th slot, 3rd layer of the 39th slot Slot 9, 1st layer, Slot 50, 1st layer, Slot 39, 2nd layer, Slot 50, 3rd layer, Slot 39, 4th layer, Slot 50, 5th layer, Slot 39, 6th layer, Slot 51, 6th layer, Slot 62, 5th layer, Slot 51, 4th layer, Slot 62, 3rd layer, Slot 51, 2nd layer, Slot 62, 1st layer, Slot 3, 2nd layer, Slot 64, 3rd layer, Slot 64, 4th layer, Slot 3, 5th layer, Slot 64, 6th layer.

[0089] That is, each branch is first arranged from the 6th layer located at the outermost layer of the stator slot 3, and a coil is arranged from the 6th layer to the 5th layer according to the span of 11, and the second coil is arranged at the same position from the 4th layer to the 3rd layer, and the third coil is arranged at the same position from the 2nd layer to the 1st layer, and the first layer is commutated along the first direction, and the coil is arranged from the 1st layer to the 6th layer in the reverse direction. The second commutation is performed along the first direction on the 6th layer, and the above process of winding from the 6th layer to the 1st layer and then winding from the 1st layer to the 6th layer is repeated, and two cycles are repeated, and the coil is output from the 6th layer.

[0090] For example, in the U1 branch, the flat wire winding 2 is arranged from the 1st slot, the 6th layer to the 12th slot, the 1st layer, crosses 13 stator slots 3 in the 1st layer to the 25th slot, the 1st layer, commutates along the first direction, winds in the reverse direction to the 14th slot, the 6th layer, crosses 12 stator slots 3 in the 6th layer to the 26th slot, the 6th layer, commutates along the first direction, repeats the above process, and outputs from the 62nd slot, the 6th layer.

[0091] Specifically, when the previous coil is located in the even-numbered slots of the first layer, the next coil is inserted across 13 stator slots 3 along the first direction; when the previous coil is located in the odd-numbered slots of the first layer, the next coil is inserted across 11 stator slots 3 along the first direction; when the previous coil is located in the sixth layer, the next coil is inserted across 12 stator slots 3 along the first direction. This ensures that each branch is evenly and symmetrically arranged and the potential of each branch is balanced.

[0092] The U2 branch and the U2' branch are obtained by offsetting the U1 branch and the U1' branch by one stator slot 3 respectively.

[0093] The V, V' phase and W, W' phase windings are obtained by circumferentially spacing the U, U' phase windings at 120 degrees and 240 degrees electrical angle arrays respectively. Each phase winding is evenly and symmetrically distributed, with balanced winding layers, low harmonic content, high torque density, small span between the line end and the welding end, high efficiency and strong fault tolerance.

[0094] Embodiment 4

[0095] like Figure 7 As shown, the 72-slot 6-pole 6-layer motor in the embodiment of the present application has 1 branch per phase winding, the solid line is the formed end of the flat wire coil, and the dotted line is the welding end. For clarity, the schematic diagram only shows the connection relationship between the U and U' phase windings. The V, V' phase and W, W' phase windings can be obtained by the U and U' phase windings being spaced 120 degrees and 240 degrees apart in the circumferential direction. The digital numbers in the U numbers and U numbers' represent the number of branches, and the absence of 'and the presence of 'represent the first set of windings and the second set of windings of the dual three-phase respectively; for example, the digital numbers of U and U', such as U1 and U1', represent the first branch of the first set of windings of the U phase and the first branch of the second set of windings of the U phase respectively.

[0096] The winding method of U1 branch is: 6th layer of the 1st slot, 5th layer of the 12th slot, 4th layer of the 1st slot, 3rd layer of the 12th slot, 2nd layer of the 1st slot, 1st layer of the 12th slot, 1st layer of the 25th slot, 2nd layer of the 14th slot, 3rd layer of the 25th slot, 4th layer of the 14th slot, 5th layer of the 25th slot, 6th layer of the 14th slot, 6th layer of the 2nd slot, 5th layer of the 13th slot, 4th layer of the 2nd slot, 3rd layer of the 13th slot, 2nd layer of the 2nd slot, 4th ... 1st floor of slot 24, 1st floor of slot 13, 2nd floor of slot 24, 3rd floor of slot 13, 4th floor of slot 24, 5th floor of slot 13, 6th floor of slot 25, 5th floor of slot 36, 4th floor of slot 25, 3rd floor of slot 36, 2nd floor of slot 25, 1st floor of slot 36, 1st floor of slot 49, 2nd floor of slot 38, 3rd floor of slot 49, 4th floor of slot 38, 5th floor of slot 49, 38th floor 6th layer, 6th layer of slot 26, 5th layer of slot 37, 4th layer of slot 26, 3rd layer of slot 37, 2nd layer of slot 26, 1st layer of slot 37, 1st layer of slot 48, 2nd layer of slot 37, 3rd layer of slot 48, 4th layer of slot 37, 5th layer of slot 48, 6th layer of slot 37, 6th layer of slot 49, 5th layer of slot 60, 4th layer of slot 49, 3rd layer of slot 60, 2nd layer of slot 49, 60th layer 1st layer, 1st layer of slot 1, 2nd layer of slot 62, 3rd layer of slot 1, 4th layer of slot 62, 5th layer of slot 1, 6th layer of slot 62, 6th layer of slot 50, 5th layer of slot 61, 4th layer of slot 50, 3rd layer of slot 61, 2nd layer of slot 50, 1st layer of slot 61, 1st layer of slot 72, 2nd layer of slot 61, 3rd layer of slot 72, 4th layer of slot 61, 5th layer of slot 72, 6th layer of slot 61.

[0097] That is, each branch is first arranged from the 6th layer located at the outermost layer of the stator slot 3, and a coil is arranged from the 6th layer to the 5th layer according to a span of 11, and the second coil is arranged at the same position from the 4th layer to the 3rd layer, and the third coil is arranged at the same position from the 2nd layer to the 1st layer. The first layer is commutated along the first direction, and the coil is arranged from the 1st layer to the 6th layer in the reverse direction. The second commutation is performed in the 6th layer along the second direction, which is opposite to the first direction, and the above winding from the 6th layer to the 1st layer is repeated, and then from the 1st layer to the 6th layer. When returning to the 6th layer again, 12 coils are crossed along the first direction, and the above process is repeated twice, completing a total of three reciprocating winding cycles, and output from the 6th layer.

[0098] The flat wire winding 2 is commutated in the 1st and 6th layers. When the previous coil is located in the even slots of the 1st layer, the next coil is inserted across 13 stator slots 3 along the first direction; when the previous coil is located in the odd slots of the 1st layer, the next coil is inserted across 11 stator slots 3 along the first direction; when the previous coil is located in the even slots of the 6th layer, the next coil is inserted across 12 stator slots 3 along the second direction; when the previous coil is located in the odd slots of the 6th layer, the next coil is inserted across 12 stator slots 3 along the first direction. This ensures that each branch is evenly and symmetrically arranged and the potential of each branch is balanced.

[0099] The U1' branch can be obtained by offsetting the U1 branch by 2 stator slots 3. It is input from the 3rd slot, 6th layer, and output from the 63rd slot, 6th layer.

[0100] The V, V' phase windings and the W, W' phase windings are obtained by circumferentially arranging the U, U' phase windings at electrical angles of 120 degrees and 240 degrees, respectively.

[0101] It can be seen from the above four embodiments of the 72-slot 6-pole 6-layer motor using 6 branches, 3 branches, 2 branches and 1 branch respectively that these four windings have different numbers of parallel branches. Except for the different bridge wires, the other line types are consistent, the line type is the least, the electrical and winding layer numbers are balanced, the harmonic content is low, the torque density is high, the span between the line end and the welding end is small, the efficiency is high, and the fault tolerance is strong.

[0102] Embodiment 5

[0103] The following takes a 96-slot 8-pole 8-layer motor as an example to illustrate the versatility of the low harmonic flat wire stator in this application in motors with different slot numbers, pole numbers, and layer numbers. The number of stator slots occupied by each pole and each phase of the 96-slot 8-pole 8-layer motor is 2, with a total of 8 poles and 6 phases, so the stator slot 3 is provided with 96 stator slots 3 along the circumferential direction, m=8, n=4, p=12, and the double three-phase flat wire winding 2 is symmetrically arranged in the stator slot 3 with a span of 11 and double short distance.

[0104] like Figure 8 As shown, the 96-slot 8-pole 8-layer motor in the embodiment of the present application has 8 branches per phase winding, the solid line is the formed end of the flat wire coil, and the dotted line is the welding end. U1 and U1' respectively represent the first branch of the first set of U-phase windings and the first branch of the second set of U-phase windings.

[0105] The winding method of U1 branch is: 8th layer in the 1st slot, 7th layer in the 12th slot, 6th layer in the 1st slot, 5th layer in the 12th slot, 4th layer in the 1st slot, 3rd layer in the 12th slot, 2nd layer in the 1st slot, 1st layer in the 12th slot, 1st layer in the 25th slot, 2nd layer in the 14th slot, 3rd layer in the 25th slot, 4th layer in the 14th slot, 5th layer in the 25th slot, 6th layer in the 14th slot, 7th layer in the 25th slot, and 8th layer in the 14th slot.

[0106] The winding method of U1' branch is: 8th layer in the 3rd slot, 7th layer in the 14th slot, 6th layer in the 3rd slot, 5th layer in the 14th slot, 4th layer in the 3rd slot, 3rd layer in the 14th slot, 2nd layer in the 3rd slot, 1st layer in the 14th slot, 1st layer in the 27th slot, 2nd layer in the 16th slot, 3rd layer in the 27th slot, 4th layer in the 16th slot, 5th layer in the 27th slot, 6th layer in the 16th slot, 7th layer in the 27th slot, and 8th layer in the 16th slot.

[0107] In this embodiment, the motor pole pitch is 12, and the flat wire coils are arranged in two adjacent layers of the stator slots 3. The two ends of the formed ends of the flat wire coils are separated by 11 stator slots 3, that is, the span of the flat wire winding 2 in this embodiment is 11. The welding ends of the two adjacent flat wire coils in the branch are welded and connected, so that the two flat wire coils are connected in series, and the span of the two welding ends is also 11, that is, double short-distance symmetrical arrangement. All the flat wire coils in the stator slots 3 have the same span of 11, and only coils of the same linear type need to be used in every two layers of stator slots 3, and a total of 4 linear types are required for 8 layers.

[0108] The flat wire winding 2 in this embodiment is arranged in a clockwise direction. When the winding direction is opposite, the flat wire winding 2 arranged according to the above principle is still applicable, and the starting position can be any stator slot 3 .

[0109] The U2 branch and the U2' branch are obtained by offsetting the U1 branch and the U1' branch by one stator slot 3, constituting the first winding unit. The second winding unit includes the U3, U3', U4, and U4' branches, which are obtained by offsetting the first winding unit by 24 stator slots 3. The third winding unit includes the U5, U5', U6, and U6' branches, which are obtained by offsetting the first winding unit by 48 stator slots 3. The fourth winding unit includes the U7, U7', U8, and U8' branches, which are obtained by offsetting the first winding unit by 72 stator slots 3.

[0110] The V, V' phase windings and the W, W' phase windings can be obtained by forming arrays of the U, U' phase windings with electrical angles of 120 degrees and 240 degrees, respectively, in the circumferential direction.

[0111] That is, each branch is first arranged from the 8th layer located at the outermost layer of the stator slot 3, and a coil is arranged from the 8th layer to the 7th layer according to a span of 11, and the second coil is arranged at the same position from the 6th layer to the 5th layer, and the third coil is arranged at the same position from the 4th layer to the 3rd layer. The fourth coil is arranged at the same position from the 2nd layer to the 1st layer, and the commutation is performed along the first direction at the 1st layer, and the output is arranged in reverse from the 1st layer to the 8th layer.

[0112] The flat wire winding 2 is commutated once in the first layer, and the welding ends of two adjacent flat wire coils are welded and connected. In the U1 branch and the U1' branch, the two adjacent flat wire coils in the first layer span 13 stator slots 3; in the U2 branch and the U2' branch, the two adjacent flat wire coils in the first layer span 11 stator slots 3.

[0113] Specifically, when the previous coil is located in the even-numbered slots of the first layer, the next coil is inserted across 13 stator slots 3 along the first direction; when the previous coil is located in the odd-numbered slots of the first layer, the next coil is inserted across 11 stator slots 3 along the first direction, so that each branch is uniformly symmetrical and the potential of each branch is balanced.

[0114] Compared with the 72-slot 6-pole 6-layer motor with 6-branch windings, the 96-slot 8-pole 8-layer motor with 8-branch windings only differs in the number of branches, slots and layers. The arrangement of the branches is exactly the same. The flat wire coils in the U1 branch are arranged in the 1st and 12th slots, the 25th and 14th slots, with a span of 11.

[0115] Figures 9 to 11 The U-phase winding arrangement principles of the 96-slot 8-pole 8-layer motor with 4 branches, 2 branches, and 1 branch are respectively described. They can all be obtained by adjusting the winding method of the above 96-slot 8-pole 8-layer 6-branch according to the adjustment method of Embodiments 1 to 4, and will not be repeated here.

[0116] The winding method of the flat wire winding 2 of the 96-slot 8-pole 8-layer motor and the 72-slot 6-pole 6-layer motor in the embodiment of the present application is similar, and both can be obtained by slightly modifying the winding method of each branch of the 72-slot 6-pole 6-layer motor. It can be understood that this winding method is applicable when the number of stator slots occupied by each pole and each phase in the dual three-phase motor is 2, the number of stator slots is a multiple of 24, and the stator slots 3 are divided into an even number of layers.

[0117] Embodiment 6

[0118] The number of slots per pole per phase of the above two motors is 2. Next, a 48-slot, 8-pole, 8-layer motor is used as an example to illustrate the versatility of the low-harmonic flat wire stator in this application in motors with different numbers of slots per pole per phase. The number of stator slots occupied by each pole per phase of the 48-slot, 8-pole, 8-layer motor is 1, with a total of 8 poles and 6 phases. Then, 48 stator slots 3 are arranged circumferentially, m=4, n=4, p=6, and the double three-phase flat wire winding 2 is symmetrically arranged in the stator slot 3 with a span of 5 and double short distances.

[0119] like Fig.12 As shown, the 48-slot 8-pole 8-layer motor in the embodiment of the present application has 8 branches per phase winding, the solid line is the formed end of the flat wire coil, and the dotted line is the welding end. U1 and U1' respectively represent the first branch of the first set of U-phase windings and the first branch of the second set of U-phase windings.

[0120] The winding method of U1 branch is: 8th layer in the 1st slot, 7th layer in the 6th slot, 6th layer in the 1st slot, 5th layer in the 6th slot, 4th layer in the 1st slot, 3rd layer in the 6th slot, 2nd layer in the 1st slot, 1st layer in the 6th slot, 1st layer in the 13th slot, 2nd layer in the 8th slot, 3rd layer in the 13th slot, 4th layer in the 8th slot, 5th layer in the 13th slot, 6th layer in the 8th slot, 7th layer in the 13th slot, and 8th layer in the 8th slot.

[0121] The winding method of U1' branch is: 8th layer in the 2nd slot, 7th layer in the 7th slot, 6th layer in the 2nd slot, 5th layer in the 7th slot, 4th layer in the 2nd slot, 3rd layer in the 7th slot, 2nd layer in the 2nd slot, 1st layer in the 7th slot, 12th layer in the 1st slot, 2nd layer in the 7th slot, 3rd layer in the 12th slot, 4th layer in the 7th slot, 5th layer in the 12th slot, 6th layer in the 7th slot, 7th layer in the 12th slot, and 8th layer in the 7th slot.

[0122] In this embodiment, the motor pole pitch is 6, and the flat wire coils are arranged in two adjacent layers of the stator slots 3. The two ends of the formed ends of the flat wire coils are separated by 5 stator slots 3, that is, the span of the flat wire winding 2 in this embodiment is 5. The welding ends of the two adjacent flat wire coils in the branch are welded and connected, so that the two flat wire coils are connected in series, and the span of the two welding ends is also 5, that is, double short-spacing symmetrical arrangement. All the flat wire coils in the stator slots 3 have the same span of 5, and only the same type of coils need to be used in every two layers of stator slots 3, and a total of 4 types of coils are required for 8 layers.

[0123] The flat wire winding 2 in this embodiment is arranged in a clockwise direction. When the winding direction is opposite, the flat wire winding 2 arranged according to the above principle is still applicable, and the starting position can be any stator slot 3 .

[0124] The U2 branch and the U2' branch are obtained by offsetting the U1 branch and the U1' branch by 12 stator slots 3, the U3 branch and the U3' branch are obtained by offsetting the U1 branch and the U1' branch by 24 stator slots 3, and the U4 and U4' branches are obtained by offsetting the U1 branch and the U1' branch by 36 stator slots 3.

[0125] The V, V' phase windings and the W, W' phase windings can be obtained by forming arrays of the U, U' phase windings with electrical angles of 120 degrees and 240 degrees, respectively, in the circumferential direction.

[0126] That is, each branch is first arranged from the 8th layer located at the outermost layer of the stator slot 3, and a coil is arranged from the 8th layer to the 7th layer according to a span of 5, and the second coil is arranged at the same position from the 6th layer to the 5th layer, and the third coil is arranged at the same position from the 4th layer to the 3rd layer, and the fourth coil is arranged at the same position from the 2nd layer to the 1st layer. Reversal is performed along the first direction at the 1st layer, and the output is arranged in reverse from the 1st layer to the 8th layer.

[0127] The flat wire winding 2 is commutated once in the first layer, and the welding ends of two adjacent flat wire coils are welded and connected. In the U1 branch and the U1' branch, the two adjacent flat wire coils in the first layer span seven stator slots 3; in the U2 branch and the U2' branch, the two adjacent flat wire coils in the first layer span five stator slots 3.

[0128] Specifically, when the previous coil is located in the even-numbered slots of the first layer, the next coil is inserted across 7 stator slots 3 along the first direction; when the previous coil is located in the odd-numbered slots of the first layer, the next coil is inserted across 5 stator slots 3 along the first direction, so that each branch is uniformly symmetrical and the potential of each branch is balanced.

[0129] Compared with the 72-slot, 6-pole, 6-layer motor with 6-branch windings, the 48-slot, 8-pole, 8-layer motor with 4-branch windings has a different number of slots per pole, but the branch arrangement is basically the same. Only the span of the coil is adjusted due to the change in pole pitch.

[0130] Fig.13 and Fig.14 The U-phase winding arrangement principles of the 48-slot 8-pole 8-layer motor with 2 branches and 1 branch are respectively described. Both can be obtained by adjusting the winding method of the above 48-slot 8-pole 8-layer 6 branches according to the adjustment method of Embodiments 1 to 4, and will not be repeated here.

[0131] The winding method of the flat wire winding 2 of the 48-slot 8-pole 8-layer motor and the 72-slot 6-pole 6-layer motor in the embodiment of the present application is similar, and both can be obtained by slightly adjusting the winding method of each branch of the 72-slot 6-pole 6-layer motor. It can be understood that this winding method is applicable when the number of stator slots in the dual three-phase motor is a multiple of 12 and the stator slots 3 are divided into an even number of layers.

[0132] The above-mentioned embodiments 1 to 4 illustrate that when the number of motor poles, the number of stator slots 3, the number of stator slot layers, and the number of slots per pole per phase are the same, the flat wire winding winding method in this application can adapt to the winding of different numbers of parallel branches per phase winding; embodiment 5 illustrates that when the number of motor poles, the number of stator slots 3, and the number of stator slot layers are different, the flat wire stator wound according to the same principle is still applicable; embodiment 6 illustrates the versatility of the flat wire winding winding method in this application when the number of slots per pole per phase is different. The flat wire stator winding method in the embodiments of this application can be expanded to other different dual three-phase motors according to the same principle.

[0133] The embodiment of the present invention provides a low harmonic flat wire stator, which uses two sets of independent three-phase windings, and the flat wire windings are arranged symmetrically with double short pitches. Only m types of line types are needed for 2m layers of stator slots. The two sets of windings are 30 degrees electrical angle apart in space, with a phase difference of 180°, and the amplitude remains unchanged, which can eliminate harmonics of specific orders, eliminate 6th, 18th, 30th, and 42nd order torque pulsations and radial electromagnetic force density, and improve the fundamental winding factor, thereby improving the overall stability of the motor while also improving the torque density. While maintaining fewer line types, the electrical balance of the motor, the balance of the number of winding layers, the low harmonic content, the high torque density, the small span between the cross-line end and the welding end, the high efficiency, the strong fault tolerance, and the connection scheme of the flat wire winding that is universal for different voltage platforms can be achieved, and at the same time, the equipment investment ratio can be reduced and the utilization rate of equipment and motors can be improved, so as to achieve the purpose of comprehensive cost reduction while meeting the performance.

[0134] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0135] Although the optional embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including optional embodiments and all changes and modifications that fall within the scope of the embodiments of the present invention.

[0136] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity from another entity, and do not necessarily require or imply any such actual relationship or order between these entities. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that an article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such article or terminal device. In the absence of further restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the article or terminal device including the elements.

[0137] The technical solution provided by the present invention is introduced in detail above. Specific examples are used in this article to illustrate the principle and implementation mode of the present invention. At the same time, for those skilled in the art, according to the principle and implementation mode of the present invention, there will be changes in the specific implementation mode and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A low harmonic flat wire stator, characterized in that: It comprises a stator core and a flat wire winding; the inner wall of the stator core is evenly provided with 12m stator slots along the circumferential direction, the stator slots are divided into 2n layers along the radial direction of the stator core, and the flat wire winding is wound in the stator slots; The flat wire winding includes two sets of three-phase windings, which are 30 degrees electrical angle apart in space, and the flat wire windings are arranged symmetrically in double short pitches in the stator slots; Each phase winding includes at least one parallel branch, each parallel branch includes a plurality of flat wire coils connected in series, each of the flat wire coils includes a formed end and two welding ends, and the two welding ends are respectively inserted into the 2i and 2i-1 layers of the stator slots, 1≤i≤n, wherein m, n, i are all positive integers; The pole pitch of the flat wire winding is p, and the spans of the forming end and the welding end of the flat wire coil are equal and are both p-1, wherein p≥6, and p is a positive integer; The input end of the parallel branch is located at the jth slot of the 2nth layer, inserted into the j+p-1th slot of the 2n-1th layer with a span of p-1, and then inserted into the jth slot of the 2n-2th layer with a span of p-1, and wound in descending order layer by layer between the jth slot and the j+p-1th slot until it reaches the j+p-1th slot of the 1st layer, wherein 1≤j≤12m, and j is a positive integer; The output end of the parallel branch is located at the 2nth layer, the parallel branch is inserted from the 1st layer to the 2nd layer with a span of p-1, and then inserted into the 3rd layer with a span of p-1, and is wound in ascending order layer by layer between the two stator slots until it reaches the 2nth layer; When the flat wire winding is commutated at the first layer, the welding ends of two adjacent flat wire coils are welded and connected, spanning p-1 or p+1 stator slots; when the flat wire winding is commutated at the 2nth layer, the welding ends of two adjacent flat wire coils are welded and connected, spanning p stator slots; Wherein, when 72 stator slots are evenly arranged on the inner wall of the stator core along the circumferential direction, the stator slots are divided into 6 layers along the radial direction of the core, the pole pitch is 12, and the flat wire winding includes two sets of three-phase windings of U, V, W and U', V', W', and each phase winding includes 6 branches; The winding method of the first branch of the U-phase winding, i.e., the U1 branch, is: the 6th layer of the 1st slot, the 5th layer of the 12th slot, the 4th layer of the 1st slot, the 3rd layer of the 12th slot, the 2nd layer of the 1st slot, the 1st layer of the 12th slot, the 1st layer of the 25th slot, the 2nd layer of the 14th slot, the 3rd layer of the 25th slot, the 4th layer of the 14th slot, the 5th layer of the 25th slot, and the 6th layer of the 14th slot; The winding method of the first branch of the U'-phase winding, i.e., the U1' branch, is: the 6th layer of the 3rd slot, the 5th layer of the 14th slot, the 4th layer of the 3rd slot, the 3rd layer of the 14th slot, the 2nd layer of the 3rd slot, the 1st layer of the 14th slot, the 1st layer of the 27th slot, the 2nd layer of the 16th slot, the 3rd layer of the 27th slot, the 4th layer of the 16th slot, the 5th layer of the 27th slot, and the 6th layer of the 16th slot; The U2 branch and the U2' branch are obtained by offsetting the U1 branch and the U1' branch by one stator slot, forming a first winding unit; the second winding unit includes branches U3, U3', U4, and U4', which are obtained by offsetting the first winding unit by 24 stator slots; and the third winding unit includes branches U5, U5', U6, and U6', which are obtained by offsetting the first winding unit by 48 stator slots; The flat wire winding is commutated once in the first layer, and the welding ends of two adjacent flat wire coils are welded and connected. In the U1 branch and the U1' branch, the two adjacent flat wire coils in the first layer span 13 stator slots; in the U2 branch and the U2' branch, the two adjacent flat wire coils in the first layer span 11 stator slots.

2. The flat wire stator according to claim 1, characterized in that: The V, V' phase windings and the W, W' phase windings are obtained by arraying the U, U' phase windings at electrical angles of 120 degrees and 240 degrees, respectively, along the circumferential direction.

3. A motor, characterized in that: It comprises the low harmonic flat wire stator as described in any one of claims 1-2.

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