A winding layout method for transforming a three-phase motor into a dual three-phase motor

Abstract

The present invention discloses a winding layout method for transforming a three-phase motor into a dual three-phase motor, and belongs to the field of dual three-phase motor design. The method is: obtaining the MMF vector diagram of the unit motor, and generating a folded vector diagram; dividing the phase band of the folded vector diagram according to the 60° phase band, and obtaining a basic vector set; symmetrically dividing the vectors within the main phase band range of the basic vector set, and constructing a first winding layout; if the first winding layout meets the phase separation condition, directly divide the phases to generate a winding layout scheme for a dual three-phase motor; otherwise, generate an offset vector set based on the basic vector set, and construct a second winding layout; the first winding layout and the second winding layout are combined in series to form a winding layout scheme that meets the phase separation condition of the dual three-phase motor. The present invention solves the design problem of using a three-phase motor slot-pole matching scheme to perform a dual three-phase motor winding layout, so that the dual three-phase motor design can be universal with existing three-phase motor punching sheets and tooling.

Description

Technical Field

[0001] The invention belongs to the field of dual three-phase motor design, and in particular relates to a winding layout method for transforming a three-phase motor into a dual three-phase motor. Background Art

[0002] The drive motor is one of the three electric components of new energy vehicles and has an important impact on the vehicle's operating performance and safety performance. Compared with three-phase motors, multi-phase motors have the characteristics of high power, high efficiency, high fault tolerance and low torque fluctuation, making them very suitable as drive motors for new energy vehicles. High power and low torque fluctuation can achieve high-power and stable operation of the vehicle, high efficiency can increase the vehicle's cruising range, and fault tolerance can prevent the vehicle from completely losing power output due to a controller drive axle failure or a motor phase winding failure, thereby increasing the safety of the vehicle during operation.

[0003] The dual three-phase motor belongs to the field of multi-phase motors. Since the dual three-phase motor suppresses the 5th and 7th harmonics of the armature magnetomotive force on the basis of the three-phase motor, the magnetomotive force harmonic content of the motor stator is low, and it has good vibration suppression characteristics; at the same time, the design method, control ideas and drive circuit of the dual three-phase motor are strongly related to the three-phase motor. Therefore, the dual three-phase motor has always been the research focus in the field of multi-phase motors, and it is also an important research direction for the next generation of new energy vehicle drive motors. Therefore, the study of the dual three-phase motor design based on the original three-phase motor punching, mold, and tooling can reduce the development and application costs of the dual three-phase motor and promote the development and application of the dual three-phase motor.

[0004] At present, the design of dual three-phase motors has high requirements for slot-pole matching, requiring the number of slots in the unit motor to be a multiple of 12, and forming a winding layout plan for the dual three-phase motor in the form of a double-layer winding. For other slot-pole matchings where the number of slots in the unit motor is not a multiple of 12, it cannot be transformed into a dual three-phase motor because the winding is inseparable or the angular interval between the secondary phases does not meet the requirements, which limits the freedom of slot-pole matching selection in the dual three-phase motor design process and the reuse of existing three-phase motor punchings, molds, and tooling. Summary of the invention

[0005] The present invention aims to solve the problem that dual three-phase motors have high requirements for slot-pole matching and some three-phase motors cannot be converted into dual three-phase motors through traditional winding theory, and proposes a winding layout method for transforming a three-phase motor into a dual three-phase motor. Based on the analysis of the magnetomotive force vector diagram, the present invention realizes the transformation of a general symmetrical winding three-phase motor into a dual three-phase motor through operations such as folding, multiplying, offsetting, 60° main phase band division, symmetrical division of the main phase band, and recombination of the vector diagram, thereby realizing the technical means of developing a dual three-phase motor based on the original three-phase motor facilities.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] The present invention discloses a winding layout method for transforming a three-phase motor into a dual three-phase motor, comprising the following steps:

[0008] 1) Solve the slot-pole state of the unit motor based on the slot-pole matching scheme of the three-phase motor;

[0009] 2) Obtain the MMF vector diagram of the unit motor, convert the lower half vector of the MMF vector diagram to the upper half vector diagram, and generate a folded vector diagram;

[0010] 3) Divide the phase belt of the folded vector map according to the 60° phase belt to obtain three main phase belts and obtain the basic vector set;

[0011] 4) symmetrically dividing the vectors within the main phase band range of the basic vector set to generate six secondary phase bands, and constructing a first winding layout in combination with a preset first pitch;

[0012] 5) If the first winding layout meets the phase-splitting condition, the phase is directly split to generate a winding layout scheme for a dual three-phase motor; otherwise, an offset vector set is generated based on the basic vector set, and the vectors in the main phase band range of the offset vector set are symmetrically divided to generate six secondary phase bands of the offset vector set, and the second pitch is obtained based on the first pitch, and then the second winding layout is generated; the first winding layout and the second winding layout are combined in series to form a winding layout scheme that meets the phase-splitting condition of the dual three-phase motor.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] 1) The present invention designs the winding layout of the motor based on the MMF vector diagram. In order to change the phase shift angle of the phase split, a method for generating an offset vector set is proposed. Compared with the traditional winding design based on the slot angle, more phase shift angles can be generated through the offset vector set.

[0015] 2) In the implementation process of the present invention, the basic vector set and the offset vector set are combined to generate a continuous phase shift angle between two three-phase windings, and a typical dual three-phase motor winding distribution scheme with a phase shift of 30° electrical angle can be generated.

[0016] 3) The dual three-phase motor winding layout method formed by the present invention solves the problem that the number of slots in the traditional three-phase unit motor is not an integer of 12 slot-pole matching and cannot be used for dual three-phase motor winding layout, making the dual three-phase motor design more flexible in slot and pole selection.

[0017] 4) The winding layout method formed by the present invention enables the newly designed dual three-phase motor to use the existing traditional three-phase motor tooling and molds, reducing the development and production costs of the dual three-phase motor and promoting the development and application of the dual three-phase motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a flow chart of the method of the present invention;

[0019] Figure 2 This is the phase separation process of a 24-slot 2-pole motor. The a in the figure is the MMF vector diagram of the unit motor, the b in the figure is the folded vector diagram and phase separation, and the c in the figure is the phase vector after the basic vector set is phase-separated;

[0020] Figure 3 It is the phase separation process of the 18-slot 2-pole motor. a in the figure is the MMF vector diagram of the unit motor, b in the figure is the folded vector diagram and phase separation, c in the figure is the phase vector after the basic vector set is phase separated, d in the figure is the offset vector set and phase separation, e in the figure is the phase vector after the offset vector set is phase separated, and f in the figure is the phase vector after the combination and phase separation;

[0021] Figure 4 It is the phase separation process of a 15-slot 2-pole motor. a in the figure is the MMF vector diagram of the unit motor, b in the figure is the folded vector diagram, c in the figure is the basic vector set and phase separation, d in the figure is the phase vector after the basic vector set is phase separated, e in the figure is the offset vector set and phase separation, f in the figure is the phase vector after the offset vector set is phase separated, and g in the figure is the phase vector after the combination and phase separation;

[0022] Figure 5 This is the winding layout diagram of a 24-slot 2-pole motor;

[0023] Figure 6 This is the winding layout diagram of an 18-slot 2-pole motor;

[0024] Figure 7 This is the winding layout diagram of a 15-slot 2-pole motor. DETAILED DESCRIPTION

[0025] The present invention is further described and illustrated below in conjunction with specific embodiments. The embodiments are merely exemplary of the present disclosure and do not define the scope of limitation. The technical features of each embodiment of the present invention may be combined accordingly without conflicting with each other.

[0026] The present invention provides a winding layout method for transforming a three-phase motor into a dual three-phase motor, so that the slot-pole matching scheme originally adapted for the three-phase motor can be applied to the design of the dual three-phase motor, thereby reducing the development cost of the dual three-phase motor and promoting the application of the dual three-phase motor in new energy vehicles and other industries.

[0027] The winding layout method for converting a three-phase motor into a dual three-phase motor described in the present invention is applicable to the slot-pole coordination of a traditional symmetrical winding three-phase motor. According to the number of MMF (Magnetomotive Force) vectors of the main phase belt of the unit motor, the slot-pole coordination (slot-pole coordination scheme) of the traditional motor can be divided into three categories, namely, the main phase belt vector is an odd number, the main phase belt vector is an odd number after being divided by 2, and the main phase belt vector can be divided by 4. Based on the slot-pole coordination scheme of the traditional motor, this embodiment uses three slot-pole coordinations of 24 slots and 2 poles, 18 slots and 2 poles, and 15 slots and 2 poles to illustrate the winding layout method of the present invention.

[0028] like Figure 1 As shown in the flow chart, the winding layout method for transforming a three-phase motor into a dual three-phase motor proposed in this embodiment is specifically as follows:

[0029] Step 1): Solve the slot-pole state of the unit motor according to the slot-pole matching scheme of the three-phase motor;

[0030] The three-phase motor is a symmetrical winding three-phase motor, and the unit motor of the symmetrical winding three-phase motor satisfies the main phase slot number The condition for being an integer;

[0031] The slot-pole state includes the number of slots in the unit motor. , Number of poles of unit motor The number of main phase slots of the unit motor , the expressions are:

[0032] ;

[0033] ;

[0034] ;

[0035] Among them, s represents the number of stator slots of the three-phase motor, p represents the number of rotor stages of the three-phase motor, Represents the greatest common divisor of x and y.

[0036] For the above three three-phase motors mentioned in the embodiment, the state parameters of the corresponding unit motors are shown in the following table:

[0037]

[0038] Step 2): Based on the slot pole state of the unit motor, the MMF vector diagram of the unit motor is obtained based on the double-layer winding, and the number of vectors in the vector diagram is equal to the number of slots of the unit motor; the positive direction of the x-axis is used as the starting vector direction of the MMF vector diagram, and each vector is sorted in a counterclockwise direction; the positive and negative directions of the magnetomotive force vector are changed by reverse winding, and the vectors in the lower half of the MMF vector diagram are converted to the upper half of the MMF vector diagram to obtain a folded vector diagram.

[0039] In a specific embodiment of the present invention, the unit motor magnetomotive force MMF vector diagram of a 24-slot 2-pole motor is as follows: Figure 2 As shown in a in the figure, the unit motor magnetomotive force MMF vector diagram of the 18-slot 2-pole motor is as follows Figure 3 As shown in a in the figure, the unit motor magnetomotive force MMF vector diagram of the 15-slot 2-pole motor is as follows Figure 4 As shown in a, the number of MMF vectors in the figure is consistent with the number of slots in the unit motor. The starting vector of the vector diagram points to the positive direction of the x-axis, the starting angle is zero, and the vectors are sorted in a counterclockwise direction; the vectors in the lower half are folded in reverse to the upper half (that is, the vectors in the lower half of the MMF vector diagram are converted to the upper half of the MMF vector diagram). The folded form of the unit motor magnetomotive force MMF vector diagram of the 24-slot 2-pole motor is referenced Figure 2 b, the folded form of the unit motor magnetomotive force MMF vector diagram of the 18-slot 2-pole motor is referenced Figure 3 b, the folded form of the unit motor magnetomotive force MMF vector diagram of the 15-slot 2-pole motor is referenced Figure 4 In b, the original vector is represented by black, and the folded vector is represented by green. The vector is folded in half by reverse winding (that is, the vector in the lower half of the MMF vector diagram is converted to the upper half of the MMF vector diagram by reverse winding). The converted vector diagram is called the folded MMF vector diagram.

[0040] For 24-slot 2-pole and 18-slot 2-pole motors, since the number of slots in the unit motor is an even number, the folded vector and the original vector are collinear. To make the MMF vector diagram clear, the original vector is placed in the inner layer, called the lower layer vector, and the folded vector is placed in the outer layer, called the upper layer vector.

[0041] Step 3): Divide the phase band of the folded vector diagram according to the 60° phase band to obtain three main phase bands; the number of main phase slots of the unit motor is equal to the number of vectors in the main phase band (that is, the number of vectors in the 60° main phase band is equal to the number of main phase slots of the unit motor). If the number of vectors in the main phase band is an odd number, it is necessary to multiply the vector set in the main phase band. Specifically, superimpose an identical folded vector diagram on the folded vector diagram to realize vector multiplication to obtain a basic vector set, wherein the vector multiplication is realized by two double-layer windings; if the number of vectors in the main phase band is an even number, all vectors in the folded vector diagram constitute a basic vector set (basic MMF vector set).

[0042] In a specific embodiment of the present invention, the main phase band of the unit motor magnetomotive force MMF fold vector diagram of the 24-slot 2-pole motor is initially divided with reference to Figure 2 b, the main phase band preliminary division reference of the unit motor magnetomotive force MMF fold vector diagram of the 18-slot 2-pole motor Figure 3 b, the main phase band preliminary division reference of the unit motor magnetomotive force MMF fold vector diagram of the 15-slot 2-pole motor Figure 4 In b, different phase bands are represented by different colors, where light green represents phase A, light blue represents phase B, and pink represents phase C (the reverse of phase C).

[0043] The multiplication operation is achieved by multiplying the number of conductors in the slot, such as Figure 4 As shown in b, for a 15-slot 2-pole motor, the number of vectors in the main phase band is 5, which is an odd number. It is necessary to multiply all the vectors in the folded vector diagram. The multiplied vector diagram is as follows Figure 4 As shown in c, the number of vectors in the main phase band is 10, which is converted to an even number. For the slot-pole combination with an even number of vectors in the 60° main phase band, such as 24 slots and 2 poles and 18 slots and 2 poles, no additional multiplication operation is required, that is, all vectors in the current folded vector diagram are used as the basic vector set of the motor.

[0044] For a 15-slot 2-pole motor, since the number of slots in the unit motor is an odd number, the folded vector and the original vector are not collinear, and the original vector and the folded vector are distributed alternately; in the process of generating the basic vector set, the folded MMF vector diagram is multiplied, and the newly added folded vector diagram is collinear with the original folded vector diagram. In order to make the transformed vector diagram clear, the vector in the superimposed folded vector diagram is placed inside as the lower layer vector, and the vector in the superimposed folded vector diagram is placed outside as the upper layer vector.

[0045] Step 4): Perform symmetrical division of the vectors within the main phase band range on the basic vector set. One main phase band is divided into two secondary phase bands, and three main phase bands generate six secondary phase bands. The boundary of the symmetrical division is used as the symmetrical center line of the main phase band of the first winding layout; the first winding layout is constructed based on the preset first pitch, the sequence number of the vectors in the secondary phase band, and the forward and reverse directions of the winding.

[0046] In a specific embodiment of the present invention, a symmetrical division of the vectors within the main phase band range of the basic MMF vector set is performed to divide a main phase band into two secondary phase bands. The main phase band division reference of the unit motor magnetomotive force MMF vector of the 24-slot 2-pole motor is Figure 2 b, the main phase band division reference of the unit motor magnetomotive force MMF vector of the 18-slot 2-pole motor Figure 3 b, the main phase band division reference of the unit motor magnetomotive force MMF vector of the 15-slot 2-pole motor Figure 4 In c, the dotted lines represent the main phase belt vector division modes of the 24-slot 2-pole, 18-slot 2-pole, and 15-slot 2-pole motors, respectively; appropriate pitches are selected for the three motors, which are called the first pitches. Taking the short pitch as an example, the pitches selected in this embodiment are 11, 8, and 7, respectively; combined with the vector sequence number in step 2) and the forward and reverse directions of the winding, a winding layout is constructed by connecting the winding layers in series with the double-layer winding as a group, which is called the first winding layout. The phase vector diagrams of the first winding layouts of the three motors in this embodiment are shown as follows: Figure 2 c in Figure 3 c and Figure 4 As shown in d in the figure, the generated first winding layout is as follows Figure 5 , Figure 6 The first winding layout part, Figure 7 The first winding layout is shown in the section.

[0047] Step 5): If the first winding layout meets the phase splitting condition, the phase is directly split to generate a winding layout scheme for a dual three-phase motor; the phase splitting condition is that the two secondary phase belts obtained by decomposing the main phase belt are separated by an electrical angle of 30°.

[0048] If the first winding layout does not meet the phase-splitting condition, an offset vector set is generated based on the basic vector set, and the vectors within the main phase band range of the offset vector set are symmetrically divided to generate six secondary phase bands of the offset vector set, and the second pitch is obtained based on the first pitch, and then the second winding layout is generated; the first winding layout and the second winding layout are combined in series to form a winding layout scheme that meets the phase-splitting condition of the dual three-phase motor.

[0049] The specific method of generating an offset vector set based on a basic vector set is:

[0050] If the number of main phase slots of the unit motor is an odd number, the vector in the superimposed folded vector image is taken as the lower vector, the vector in the superimposed folded vector image is taken as the upper vector, and the upper vector of the basic vector set is offset counterclockwise by two vector interval angles to form an offset vector set;

[0051] If the number of main phase slots of the unit motor is an even number, the vector of the original upper half of the folded vector image is used as the lower vector, the vector of the converted lower half of the folded vector image is used as the upper vector, and the upper vector of the basic vector set is offset counterclockwise by a vector interval angle to form an offset vector set.

[0052] The specific method for generating the second winding layout is:

[0053] Based on the offset vector set, the vectors within the main phase band are symmetrically divided, one main phase band is divided into two sub-phase bands, three main phase bands generate six sub-phase bands, and the boundary of the symmetrical division is used as the symmetrical center line of the main phase band of the second winding layout; the second winding layout is constructed based on the second pitch, the sequence number of the vectors in the sub-phase band of the offset vector set, and the forward and reverse directions of the winding;

[0054] If the number of main phase slots of the unit motor is an odd number, the value of the second pitch is equal to the value of the first pitch; if the number of main phase slots of the unit motor is is an even number, the value of the second pitch is equal to the value of the first pitch plus one or minus one, and the value of the second pitch is the minimum value that makes the short-pitch coefficient generated based on the second pitch close to 1.

[0055] The specific method of combining the first winding layout and the second winding layout in series is:

[0056] The symmetric center line of the main phase belt of the first winding layout is aligned with the symmetric center line of the main phase belt of the second winding layout, wherein the interval angle of two secondary phase belts generated by dividing a main phase belt in the first winding layout is less than 30° electrical angle, and the interval angle of two secondary phase belts generated by dividing a main phase belt in the second winding layout is greater than 30° electrical angle. The first winding layout and the second winding layout are combined in series, so that the angular interval between the two secondary phase belts formed by dividing a main phase belt after the combination is equal to 30° electrical angle.

[0057] In a specific embodiment of the present invention, the secondary phase belt vectors formed by the three motor slot-pole schemes in step 4) based on the main phase belt of the segmented basic vector set are respectively as follows: Figure 2 c in Figure 3 c in Figure 4 As shown in d. Among them, Figure 2The c in the figure represents the phase vector state formed by the 24-slot 2-pole slot-pole scheme based on the division of the basic vector set. The angle between the two secondary phases formed by the division of the main phase belt is 30° electrical angle. The first winding layout meets the phase separation condition (the angle interval between the two secondary phases formed by the decomposition of the main phase belt is 30° electrical angle). Therefore, the phase can be directly divided to generate the first winding layout ( Figure 5 ) is the final winding layout solution, which meets the winding needs of dual three-phase motors.

[0058] Figure 3 c in Figure 4 The d in the figure represents the phase vector states of the 18-slot 2-pole slot-pole scheme and the 15-slot 2-pole slot-pole scheme based on the division of the basic vector set. The angles between the two secondary phases formed by the division of the main phase are 26.73° electrical angle and 28.83° electrical angle respectively. Obviously, the first winding layout formed does not meet the phase separation conditions of the dual three-phase motor, and it is necessary to construct an offset vector set.

[0059] For an 18-slot 2-pole motor, the number of main phase slots of the unit motor is It is equal to 6, which is an even number. It is necessary to offset the upper vector of the basic vector set by an angle interval between vectors to form an offset vector set. Figure 3 The d in the figure represents the offset vector set of the 18-slot 2-pole motor. For the 15-slot 2-pole motor, the number of main phase slots of the unit motor is It is equal to 5, which is an odd number. It is necessary to offset the upper vector of the basic vector set by two vector interval angles to form an offset vector set. Figure 4 The e in represents the offset vector set of the 15-slot 2-pole motor. The vector interval angle represents the minimum vector angle in the folded vector diagram. The vector interval angle of the motor is its inherent property, and different motors have different vector interval angles.

[0060] According to the symmetry center line of the main phase belt of the offset vector set, the vector is symmetrically divided into two parts to form the secondary phase. The division method of the 18-slot 2-pole and 15-slot 2-pole offset vector sets is as follows: Figure 3 In d, Figure 4 The e in the figure indicates that the vector is segmented by the dotted line in the figure, and the phase vector state generated after segmentation is represented by Figure 3 e in Figure 4 The f in the figure respectively represents that the second winding layout is generated by combining the second pitch, the sequence number of the vector in the secondary phase band of the offset vector set, and the forward and reverse direction of the winding.

[0061] In order to make the generated second winding layout and the main phase band center line of the first winding layout aligned in structure, the second pitch is selected as follows: For an 18-slot 2-pole motor, the number of main phase slots of the unit motor is =6, which is an even number. Therefore, the second pitch of the 18-slot 2-pole motor should be equal to the value of the first pitch plus one or minus one, and the value of the second pitch is the minimum value that makes the short pitch coefficient generated based on the second pitch close to 1. In this embodiment, 9 is selected as the pitch of the 18-slot 2-pole motor offset vector set, and the generated second winding layout is as follows: Figure 6 As shown in the second winding layout part; for a 15-slot 2-pole motor, the number of main phase slots of the unit motor is =5, which is an odd number. Therefore, the second pitch of the 15-slot 2-pole motor should be the same as the first pitch. In this embodiment, 7 is selected as the pitch of the 15-slot 2-pole motor offset vector set. The generated second winding layout is as follows: Figure 7 The second winding layout is shown in the section.

[0062] The first winding layout and the second winding layout are aligned according to the symmetric center line of the main phase belt. The alignment is achieved by rotating the offset vector set. For the 18-slot 2-pole motor, since the first pitch and the second pitch have different parity, the offset vector set moves half a vector interval clockwise; for the 15-slot 2-pole motor, the first pitch is consistent with the second pitch, and the offset vector set needs to be rotated counterclockwise by a vector interval. Among them, the interval angle of the two secondary phase belts generated by the division of a main phase belt in the first winding layout is less than 30° electrical angle, and the interval angle of the two secondary phase belts generated by the division of a main phase belt in the second winding layout is greater than 30° electrical angle. The first winding layout and the second winding layout are combined in an appropriate ratio so that the angle interval between the two secondary phase belts formed by the division of a main phase belt after the combination is equal to 30° electrical angle.

[0063] The ratio of the basic vector set and the offset vector set of the motor involved in this embodiment is shown in the following table:

[0064]

[0065] For an 18-slot 2-pole motor, the interval angle between the two secondary phase belts formed by the division of the main phase belt of the basic vector set is 26.73° electrical angle, and the interval angle between the two secondary phase belts formed by the division of the main phase belt of the offset vector set is 33.27° electrical angle. When the basic vector set accounts for 50% and the offset vector set accounts for 50%, the angle between the two secondary phase belts of the synthesized main phase belt is 30° electrical angle, such as Figure 3 As shown in f, the angles between A1 / A2, B1 / B2, and C1- / C2- are 30° electrical degrees, which meets the winding requirements of dual three-phase motors.

[0066] For a 15-slot 2-pole motor, the interval angle between the two secondary phase belts formed by the division of the main phase belt of the basic vector set is 28.83° electrical angle, and the interval angle between the two secondary phase belts formed by the division of the main phase belt of the offset vector set is 33.59° electrical angle. When the basic vector set accounts for 75% and the offset vector set accounts for 25%, the angle between the two secondary phase belts of the synthesized main phase belt is 30° electrical angle, such as Figure 4 As shown in g, the angle between A1 / A2, B1\B2, and C1- / C2- is 30° electrical angle, which meets the winding requirements of dual three-phase motors.

[0067] By adopting the above steps, the slot-pole coordination of a three-phase motor with symmetrical winding can be transformed into a dual three-phase motor through phase separation and combination based on the basic vector set and the offset vector set, so that in the design of the dual three-phase motor, the molds and tooling of the traditional three-phase motor can be used universally, reducing the development cost of the dual three-phase motor and promoting the popularization and use of the dual three-phase motor in industry.

[0068] The above-mentioned embodiments only express several implementation modes of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. For those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A winding layout method for transforming a three-phase motor into a dual three-phase motor, characterized in that: The steps include: 1) Solve the slot-pole state of the unit motor based on the slot-pole matching scheme of the three-phase motor; 2) Obtaining the MMF vector diagram of the unit motor, converting the lower half vector of the MMF vector diagram to the upper half vector diagram to generate a folded vector diagram; 3) Divide the phase belt of the folded vector diagram according to the 60° phase belt to obtain three main phase belts and obtain the basic vector set; 4) symmetrically dividing the vectors within the main phase band range of the basic vector set to generate six secondary phase bands, and constructing a first winding layout in combination with a preset first pitch; 5) If the first winding layout meets the phase splitting condition, the phase is directly split to generate a winding layout scheme for a dual three-phase motor; On the contrary, an offset vector set is generated based on the basic vector set, and the offset vector set is symmetrically divided into vectors within the main phase band range to generate six secondary phase bands of the offset vector set, and a second pitch is obtained based on the first pitch, and then a second winding layout is generated; the first winding layout and the second winding layout are combined in series to form a winding layout scheme that meets the phase separation conditions of the dual three-phase motor; The three-phase motor in step 1) is a symmetrical winding three-phase motor, and the unit motor of the symmetrical winding three-phase motor satisfies the main phase slot number S pu The condition for being an integer; The slot-pole state includes the slot number S of the unit motor. u 、Number of poles p of unit motor u The number of main phase slots of the unit motor pu , the expression is as follows: s pu =s u / 3; Where, s is the number of stator slots of the three-phase motor, p is the number of rotor poles of the three-phase motor, and gcd(x,y) is the greatest common divisor of x and y; In the step 2), based on the slot pole state of the unit motor and the double-layer winding, the MMF vector diagram of the unit motor is obtained, and the number of vectors in the vector diagram is equal to the number of slots of the unit motor; the positive direction of the x-axis is used as the starting vector direction of the MMF vector diagram, and each vector is sorted in a counterclockwise direction; the positive and negative directions of the magnetomotive force vector are changed by reverse winding, and the vectors in the lower half of the MMF vector diagram are converted to the upper half of the MMF vector diagram to obtain a folded vector diagram; In step 3), the obtaining of the basic vector set includes: The number of main phase slots of the unit motor is equal to the number of vectors in the main phase band. If the number of vectors in the main phase band is an odd number, the folded vector diagram is superimposed with an identical folded vector diagram to realize vector multiplication, thereby obtaining a basic vector set, wherein the vector multiplication is realized by two double-layer windings; If the number of vectors in the main phase band is even, all the vectors in the folded vector form the basic vector set; The step 4) comprises: Based on the basic vector set, the vectors within the main phase band are symmetrically divided, one main phase band is divided into two secondary phase bands, three main phase bands generate six secondary phase bands, and the boundary of the symmetrical division is used as the symmetrical center line of the main phase band of the first winding layout; the first winding layout is constructed based on the preset first pitch, the sequence number of the vectors in the secondary phase band, and the forward and reverse directions of the winding; In step 5), generating an offset vector set based on a basic vector set includes: If the number of main phase slots of the unit motor is s pu is an odd number, the vector in the superimposed folded vector image is taken as the lower vector, the vector in the superimposed folded vector image is taken as the upper vector, and the upper vector of the basic vector set is offset counterclockwise by two vector interval angles to form an offset vector set; If the number of main phase slots of the unit motor is s pu is an even number, the vector of the original upper half of the folded vector is taken as the lower vector, the vector of the converted lower half of the folded vector is taken as the upper vector, and the upper vector of the basic vector set is offset counterclockwise by a vector interval angle to form an offset vector set; In step 5), generating the second winding layout includes: Based on the offset vector set, the vectors within the main phase band are symmetrically divided, one main phase band is divided into two sub-phase bands, three main phase bands generate six sub-phase bands, and the boundary of the symmetrical division is used as the symmetrical center line of the main phase band of the second winding layout; the second winding layout is constructed based on the second pitch, the sequence number of the vectors in the sub-phase band of the offset vector set, and the forward and reverse directions of the winding; If the number of main phase slots of the unit motor is s pu is an odd number, the value of the second pitch is equal to the value of the first pitch; if the number of main phase slots of the unit motor is s pu is an even number, the value of the second pitch is equal to the value of the first pitch plus one or minus one, and the value of the second pitch is the minimum value that makes the short-distance coefficient generated based on the second pitch close to 1; In step 5), the first winding layout and the second winding layout are combined in series, including: The symmetric center line of the main phase belt of the first winding layout is aligned with the symmetric center line of the main phase belt of the second winding layout, wherein the interval angle of two secondary phase belts generated by dividing a main phase belt in the first winding layout is less than 30° electrical angle, and the interval angle of two secondary phase belts generated by dividing a main phase belt in the second winding layout is greater than 30° electrical angle. The first winding layout and the second winding layout are combined in series, so that the angular interval between the two secondary phase belts formed by dividing a main phase belt after the combination is equal to 30° electrical angle.

2. The winding layout method for transforming a three-phase motor into a dual three-phase motor according to claim 1, characterized in that: In step 5), the phase separation condition is that the angle between the two secondary phase bands obtained by decomposing the main phase band is equal to 30° electrical angle.

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