AC motor fractional pole-to-branch ratio winding arrangement method

Abstract

The invention discloses an alternating current motor fractional pole-to-branch ratio winding arrangement method, belongs to the field of motors, and aims to solve the problem that high-quality and high-efficiency design of an alternating current motor fractional pole-to-branch ratio winding is difficult to realize. The method comprises the following steps: 1, constructing a slot electromotive force vector; 2, setting a target threshold value; carrying out initial coding on the winding arrangement matrix, taking the initial winding arrangement matrix as a current solution, and calculating the fitness of the current solution; 3, obtaining a neighborhood solution of the current solution of the winding arrangement matrix based on a neighborhood generation method, and calculating the fitness of the neighborhood solution; if the fitness of the neighborhood solution is lower than that of the current solution, updating the current solution into the neighborhood solution; otherwise, continuing to generate a neighborhood solution and judging whether the winding arrangement matrix needs to be reinitialized according to an early stop condition; and 4, when the branch asymmetry degree is smaller than a target threshold value or the winding arrangement matrix reaches the maximum initialization frequency, updating the optimal solution of the winding arrangement matrix by using the current solution of the winding arrangement matrix, and decoding the optimal solution to obtain an optimal fractional pole-to-branch ratio winding arrangement scheme.

Description

Technical Field

[0001] The invention relates to a fractional pole-to-road ratio winding arrangement method for an AC motor, and belongs to the field of motors. Background Art

[0002] Fractional pole-to-circuit ratio windings break through the limitations of conventional winding branch symmetry conditions, reconstruct the winding arrangement rules, and have the advantages and characteristics of flexible selection of the number of stator winding parallel branches and flexible adjustment of line load. They are widely used in large-capacity AC motors such as pumped storage units, large nuclear power units, and synchronous phase regulators for ultra-high voltage direct current transmission systems. The development trend of large-capacity AC motors is characterized by continuous increase in capacity and complex and diverse operating conditions. As the core component in the electromechanical energy conversion process of AC motors, windings need to continuously optimize design schemes to adapt to the characteristics of high power output and strong transient operation of AC motors. The existing fractional pole-to-circuit ratio winding arrangement methods have the disadvantages of cumbersome arrangement process, numerous potential schemes, and high asymmetry of the arrangement results, which makes it difficult to meet the needs of high-quality and efficient design of large-capacity AC motor windings.

[0003] In the design of fractional pole-to-ratio windings for AC motors, overly complicated arrangement methods and a large number of potential arrangement schemes will reduce the design efficiency of fractional pole-to-ratio windings and extend the corresponding R&D cycle; the arrangement results of high branch asymmetry will lead to increased circulating current between winding branches, local overheating of wire rods, increased vibration, and reduced motor operating efficiency. Therefore, there is an urgent need for a fractional pole-to-ratio winding arrangement method that has both high design efficiency and low branch asymmetry, so as to achieve high-quality and efficient design of fractional pole-to-ratio windings and meet the development needs of large-capacity AC motors. Summary of the invention

[0004] In order to solve the problem that it is difficult to achieve high-quality and efficient design of AC motor fractional pole-to-circuit ratio windings due to the limitations of the complexity of the winding arrangement process, the potential number of arrangement schemes and the asymmetry of the winding branches, the present invention provides an AC motor fractional pole-to-circuit ratio winding arrangement method to achieve rapid design of fractional pole-to-circuit ratio winding arrangement schemes with low branch asymmetry.

[0005] The fractional pole-to-circuit ratio winding arrangement method of an AC motor according to the present invention comprises the following steps:

[0006] Step 1: Calculate the fractional pole-to-circuit ratio winding slot electromotive force based on the basic parameters of the motor, and arrange the slot electromotive force to construct the slot electromotive force vector;

[0007] Step 2: Set the target parameters: the target threshold of the fractional pole-to-path ratio winding branch asymmetry, set the maximum number of initialization times, the maximum number of iterations, and the maximum number of consecutive unimproved iterations of the winding arrangement matrix; perform initial encoding on the winding arrangement matrix and use the initial winding arrangement matrix as the current solution, and calculate the fitness of the current solution;

[0008] Step 3: Obtain the neighborhood solution of the current solution of the winding arrangement matrix based on the neighborhood generation method, and calculate the fitness of the neighborhood solution; if the fitness of the neighborhood solution is lower than the fitness of the current solution, update the current solution to the neighborhood solution; if the fitness of the neighborhood solution is higher than the fitness of the current solution, continue to generate neighborhood solutions and determine whether it is necessary to reinitialize the winding arrangement matrix according to the early stopping condition;

[0009] Step 4: When the branch asymmetry is less than the target threshold or the winding arrangement matrix reaches the maximum initialization times, the current solution of the winding arrangement matrix is ​​used to update the optimal solution of the winding arrangement matrix, and the optimal solution is decoded to obtain the optimal fractional pole-to-path ratio winding arrangement scheme.

[0010] Preferably, the process of constructing the slot electromotive force vector in step 1 is:

[0011] Step 11, give the basic parameters of the AC motor: number of slots Z, number of pole pairs p, number of motor phases m, number of parallel branches a and number of harmonics k;

[0012] Step 12: Calculate the electrical angle α between slots:

[0013]

[0014] Step 13, calculate the number of slots b per phase:

[0015]

[0016] Step 14: Calculate the slot electromotive force e of each slot s :

[0017] e s =cos(s·α·k)+jsin(s·α·k)

[0018] Where s is the slot number of the slot where the upper side of the fractional pole ratio winding coil is located;

[0019] Step 15: Arrange the slot electromotive force vector E = [e1, e2, ..., e Z / m ] T .

[0020] Preferably, the process of obtaining the fitness in step 2 is:

[0021] Step 2a1, initializing the winding arrangement matrix to obtain the winding arrangement matrix A;

[0022] Step 2a2: Calculate the branch circuit composite slot electromotive force E b :

[0023] E b =A·E

[0024] Step 2a3: Calculate Eb The amplitude and phase of each element in is based on E b The amplitude and phase of each element in the calculation of amplitude asymmetry and phase asymmetry:

[0025]

[0026] Where ΔE is the amplitude asymmetry, Δδ is the phase asymmetry, and E b_mag The electromotive force vector E of the combined slot is b The vector composed of the amplitudes of each element in E b_pha The electromotive force vector E of the combined slot is b The vector composed of the phases of each element in;

[0027] Step 2a4, the fitness f is obtained as follows:

[0028] f=W m ΔE 2 +W δ ·Δδ 2

[0029] Where W m is the amplitude asymmetry weight, W δ is the phase asymmetry weight.

[0030] Preferably, in step 2, the winding arrangement matrix is ​​initially encoded, and the encoding process is as follows:

[0031] Step 2b1, using the number of fractional pole-to-circuit ratio winding branches a and the number of positive phase belt slots b of a certain phase as the number of rows and columns to generate the positive phase belt winding arrangement matrix A + , ensure that there are only "0" elements and "1" elements in the matrix, and the number of "1" elements in each row is the same, and each column has only one "1" element;

[0032] Step 2b2, copy the positive phase winding arrangement matrix A + Get the negative phase winding arrangement matrix A - The positive and negative phase winding arrangement matrices are formed into a winding arrangement matrix element set G with row vectors as basic elements;

[0033] Step 2b3, combine the basic elements in the winding arrangement matrix element set G in pairs to obtain a winding arrangement matrix A with the number of rows being the number of winding branches a and the number of columns being a certain corresponding number of slots Z / m.

[0034] Preferably, in step 3, the method for generating the neighborhood solution of the winding arrangement matrix is ​​to perform pairwise combinations of any basic elements in the winding arrangement matrix element set;

[0035] Preferably, the early stopping condition in step three is: the number of times the neighborhood solution is generated reaches the maximum number of consecutive unimproved iterations; if the early stopping condition is met, the winding arrangement matrix is ​​reinitialized and step three is executed again.

[0036] Preferably, the triggering condition for updating the optimal solution of the winding arrangement matrix using the current solution of the winding arrangement matrix in step 4 is any one of the following conditions:

[0037] Condition 1: ΔE and Δδ are satisfied at the same time: the current amplitude asymmetry ΔE is less than the amplitude asymmetry target threshold, and the current phase asymmetry Δδ is less than the phase asymmetry target threshold;

[0038] Condition 2: The winding arrangement matrix reaches the maximum number of initialization times.

[0039] Preferably, the amplitude asymmetry target threshold is set to 0.5%, and the phase asymmetry target threshold is set to 0.5°.

[0040] Preferably, in step 4, the optimal solution is decoded to obtain the optimal fractional pole-to-path ratio winding arrangement scheme, and the decoding process includes:

[0041] Step 41, calculating the number of rows of the optimal solution of the winding arrangement matrix A and the number of "1" elements in each row, so as to determine the number of rows a and the number of columns N of the winding arrangement matrix B after decoding;

[0042] Step 42, obtaining the column index of the "1" element in each row of the winding arrangement matrix A, and determining the phase band and corresponding slot number to which the column vector belongs according to the column index;

[0043] Step 43, assign the slot numbers corresponding to the column vectors of the winding arrangement matrix A to the decoded winding arrangement matrix B in row order to obtain a single-phase winding arrangement scheme;

[0044] Step 44: The arrangement rules of the remaining phase windings are the same as that of the single-phase winding, thereby obtaining an optimal fractional pole-to-circuit ratio winding arrangement scheme.

[0045] Beneficial effects of the present invention:

[0046] The present invention provides a fractional pole-to-circuit ratio winding arrangement method for an AC motor. A winding arrangement matrix is ​​used to simulate a fractional pole-to-circuit ratio winding arrangement scheme and fitness is proposed to evaluate the asymmetry of winding branches. Different winding arrangement matrices are obtained based on a neighborhood generation method and a winding arrangement scheme with a lower fitness is quickly obtained through initialization and iteration of the winding arrangement matrix, thereby improving the design efficiency of the fractional pole-to-circuit ratio winding motor, shortening the research and development cycle of the fractional pole-to-circuit ratio winding motor, saving corresponding research and development costs, and having strong engineering value. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1It is a flow chart of a fractional pole-to-circuit ratio winding arrangement method for an AC motor according to the present invention;

[0048] Figure 2 A flowchart of the winding arrangement matrix encoding method of the present invention;

[0049] Figure 3 A flowchart of the winding arrangement matrix decoding method of the present invention;

[0050] Figure 4 A schematic diagram of a preferred fractional pole-to-circuit ratio winding arrangement scheme according to the present invention;

[0051] Figure 5 A schematic diagram of the unfolding of the A-phase winding in the preferred fractional pole-to-circuit ratio winding arrangement scheme provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0052] 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 only 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 scope of protection of the present invention.

[0053] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0054] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0055] Specific implementation method 1: The following is combined Figures 1 to 5 The present embodiment is described. The fractional pole-to-circuit ratio winding arrangement method of the AC motor described in the present embodiment comprises the following steps:

[0056] Step 1: Calculate the fractional pole-to-circuit ratio winding slot electromotive force based on the basic parameters of the motor, and arrange the slot electromotive force to construct the slot electromotive force vector;

[0057] Step 2: Set the target parameters: the target threshold of the fractional pole-to-path ratio winding branch asymmetry, set the maximum number of initialization times, the maximum number of iterations, and the maximum number of consecutive unimproved iterations of the winding arrangement matrix; perform initial encoding on the winding arrangement matrix and use the initial winding arrangement matrix as the current solution, and calculate the fitness of the current solution;

[0058] Step 3: Obtain the neighborhood solution of the current solution of the winding arrangement matrix based on the neighborhood generation method, and calculate the fitness of the neighborhood solution; if the fitness of the neighborhood solution is lower than the fitness of the current solution, update the current solution to the neighborhood solution; if the fitness of the neighborhood solution is higher than the fitness of the current solution, continue to generate neighborhood solutions and determine whether it is necessary to reinitialize the winding arrangement matrix according to the early stopping condition;

[0059] Step 4: When the value is less than the target threshold or the maximum number of initializations is reached, the current solution of the winding arrangement matrix is ​​used to update the optimal solution of the winding arrangement matrix, and the optimal solution is decoded to obtain the optimal fractional pole-to-path ratio winding arrangement scheme.

[0060] Step 1: Calculate the fractional pole-to-circuit ratio winding slot electromotive force based on the basic parameters of the motor, and arrange the slot electromotive force to construct the slot electromotive force vector;

[0061] The process of constructing the slot electromotive force vector is:

[0062] Step 11, give the basic parameters of the AC motor: number of slots Z, number of pole pairs p, number of motor phases m, number of parallel branches a and number of harmonics k;

[0063] Step 12: Calculate the electrical angle α between slots:

[0064]

[0065] Step 13, calculate the number of slots b per phase:

[0066]

[0067] Step 14: Calculate the slot electromotive force e of each slot s :

[0068] e s =cos(s·α·k)+jsin(s·α·k) (3)

[0069] Where s is the slot number of the slot where the upper side of the fractional pole ratio winding coil is located;

[0070] Step 15: Arrange the slot electromotive force vector E = [e1, e2, ..., e Z / m ] T .

[0071] Step 2: Set the target parameters: the target threshold of the fractional pole-to-path ratio winding branch asymmetry, set the maximum number of initialization times, the maximum number of iterations, and the maximum number of consecutive unimproved iterations of the winding arrangement matrix; perform initial encoding on the winding arrangement matrix and use the initial winding arrangement matrix as the current solution, and calculate the fitness of the current solution;

[0072] According to the design requirements of AC motors, the target thresholds for amplitude asymmetry are set to 0.5%, and the target thresholds for phase asymmetry are set to 0.5°; the maximum number of initialization times for the winding arrangement matrix is ​​set to t1, the maximum number of iterations is set to t2, and the maximum number of consecutive unimproved iterations is set to t3.

[0073] The process of obtaining fitness in step 2 is:

[0074] Step 2a1, initializing the winding arrangement matrix to obtain the winding arrangement matrix A;

[0075] Step 2a2: Calculate the branch circuit composite slot electromotive force E b :

[0076] E b =A·E (4)

[0077] Where A is the winding arrangement matrix after initial encoding;

[0078] Step 2a3: Calculate E b The amplitude and phase of each element in is based on E b The amplitude and phase of each element in the calculation of amplitude asymmetry and phase asymmetry:

[0079]

[0080] Where ΔE is the amplitude asymmetry, Δδ is the phase asymmetry, and E b_mag The electromotive force vector E of the combined slot is b The vector composed of the amplitudes of each element in E b_pha The electromotive force vector E of the combined slot is b The vector composed of the phases of each element in;

[0081] Step 2a4, the fitness f is obtained as follows:

[0082] f=W m ΔE 2 +W δ ·Δδ 2 (6)

[0083] Where W m is the amplitude asymmetry weight, W δ is the phase asymmetry weight.

[0084] The fractional pole-to-road ratio winding arrangement matrix A is initially encoded. The encoding method is a combination of two basic elements in the winding arrangement matrix element set. The basic elements are the row vectors of the positive phase band winding arrangement matrix and the negative phase band winding arrangement matrix. The number of rows and the number of columns of the winding arrangement matrix are the number of winding branches and the number of slots corresponding to a certain phase, respectively; the number of rows and the number of columns of the positive phase band winding arrangement matrix are the number of winding branches and the number of slots corresponding to a certain phase, respectively. There are only two types of elements, "0" and "1", in the matrix, and the number of "1" elements in each row is the same, and each column has only one "1" element; the positive phase band winding arrangement matrix is ​​the same as the negative phase band winding arrangement matrix.

[0085] The specific encoding method flow chart is as follows Figure 2 The encoding process is as follows:

[0086] Step 2b1, using the number of fractional pole-to-circuit ratio winding branches a and the number of positive phase belt slots b of a certain phase as the number of rows and columns to generate the positive phase belt winding arrangement matrix A + , ensure that there are only "0" elements and "1" elements in the matrix, and the number of "1" elements in each row is the same, and each column has only one "1" element;

[0087] Step 2b2, copy the positive phase winding arrangement matrix A + Get the negative phase winding arrangement matrix A - The positive and negative phase winding arrangement matrices are formed into a winding arrangement matrix element set G with row vectors as basic elements;

[0088] Step 2b3, combine the basic elements in the winding arrangement matrix element set G in pairs to obtain a winding arrangement matrix A with the number of rows being the number of winding branches a and the number of columns being a certain corresponding number of slots Z / m.

[0089] Step 3: Obtain the neighborhood solution of the current solution of the winding arrangement matrix based on the neighborhood generation method, and calculate the fitness of the neighborhood solution; if the fitness of the neighborhood solution is lower than the fitness of the current solution, update the current solution to the neighborhood solution; if the fitness of the neighborhood solution is higher than the fitness of the current solution, continue to generate neighborhood solutions and determine whether it is necessary to reinitialize the winding arrangement matrix according to the early stopping condition;

[0090] By combining any basic elements in the winding arrangement matrix element set in pairs, the neighborhood solution of the winding arrangement matrix is ​​obtained and the fitness of the neighborhood solution is calculated according to formula (4) to formula (6). The fitness of the neighborhood solution is compared with the current fitness and it is determined whether to stop early due to reaching the maximum number of consecutive unimproved iterations t3 or whether the winding arrangement matrix needs to be initialized. If the early stopping condition is met, the winding arrangement matrix is ​​reinitialized and step 3 is re-executed.

[0091] Step 4: When the branch asymmetry is less than the target threshold or the winding arrangement matrix reaches the maximum initialization times, the current solution of the winding arrangement matrix is ​​used to update the optimal solution of the winding arrangement matrix, and the optimal solution is decoded to obtain the optimal fractional pole-to-path ratio winding arrangement scheme.

[0092] According to the position of the "1" element in the column vector of the optimal solution of the winding arrangement matrix and the corresponding phase band, the winding branch and slot number are matched to obtain the optimal fractional pole-to-circuit ratio winding arrangement scheme.

[0093] When condition 1 or condition 2 is met, the winding arrangement matrix is ​​updated to be the preferred solution as the current solution.

[0094] Condition 1: ΔE and Δδ are satisfied at the same time: the current amplitude asymmetry ΔE is less than the amplitude asymmetry target threshold, and the current phase asymmetry Δδ is less than the phase asymmetry target threshold;

[0095] Condition 2: The winding arrangement matrix reaches the maximum number of initialization times.

[0096] The optimal solution is decoded according to the position of the "1" element in the column vector of the optimal solution of the winding arrangement matrix A and the phase band to which it belongs. Based on the decoded winding arrangement matrix B, the optimal fractional pole-to-path ratio winding arrangement scheme is obtained. The flowchart of the decoding method is as follows: Figure 3 The decoding process includes:

[0097] Step 41, calculating the number of rows of the optimal solution of the winding arrangement matrix A and the number of "1" elements in each row, so as to determine the number of rows a and the number of columns N of the winding arrangement matrix B after decoding;

[0098] Step 42, obtaining the column index of the "1" element in each row of the winding arrangement matrix A, and determining the phase band and corresponding slot number to which the column vector belongs according to the column index;

[0099] Step 43, assign the slot numbers corresponding to the column vectors of the winding arrangement matrix A to the decoded winding arrangement matrix B in row order to obtain a single-phase winding arrangement scheme;

[0100] Step 44: The arrangement rules of the remaining phase windings are the same as that of the single-phase winding, thereby obtaining an optimal fractional pole-to-circuit ratio winding arrangement scheme.

[0101] The optimal fractional pole-to-circuit ratio winding arrangement scheme is as follows Figure 4 As shown, the arrangement scheme of the slot number s where the upper side of the A-phase winding is located is determined by the decoded winding arrangement matrix B. The decoded winding arrangement matrix The B and C phases are based on the A phase winding arrangement scheme and add c and 2c. The calculation method of the number of windings per phase under each pole pair c is shown in formula (7):

[0102]

[0103] If the current winding slot number is greater than the slot number Z after decoding, the current winding slot number is subtracted from the slot number Z, and the difference is updated as the current winding slot number. Taking a three-phase AC motor with a pole pair number p of 1, a stator winding parallel branch number a of 3, a stator slot number Z of 72, and a pitch of 29 as an example, the A-phase winding expansion diagram in the optimal fractional pole-to-circuit ratio winding arrangement scheme of the example motor is given as follows Figure 5 The fitness of the current optimal fractional pole-to-circuit ratio winding arrangement scheme is 0, the amplitude asymmetry is 0.38%, the phase asymmetry is 0, and the winding arrangement process takes 4 seconds.

[0104] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It should also be understood that the features described in conjunction with a single embodiment may be used in other described embodiments.

Claims

1. A fractional pole-to-circuit ratio winding arrangement method for an AC motor, characterized in that: The method comprises the following steps: Step 1: Calculate the fractional pole-to-circuit ratio winding slot electromotive force based on the basic parameters of the motor, and arrange the slot electromotive force to construct the slot electromotive force vector; Step 2: Set the target parameters: the target threshold of the fractional pole-to-path ratio winding branch asymmetry, set the maximum number of initialization times, the maximum number of iterations, and the maximum number of consecutive unimproved iterations of the winding arrangement matrix; perform initial encoding on the winding arrangement matrix and use the initial winding arrangement matrix as the current solution, and calculate the fitness of the current solution; Step 3: Obtain the neighborhood solution of the current solution of the winding arrangement matrix based on the neighborhood generation method, and calculate the fitness of the neighborhood solution; if the fitness of the neighborhood solution is lower than the fitness of the current solution, update the current solution to the neighborhood solution; if the fitness of the neighborhood solution is higher than the fitness of the current solution, continue to generate neighborhood solutions and determine whether it is necessary to reinitialize the winding arrangement matrix according to the early stopping condition; Step 4: When the branch asymmetry is less than the target threshold or the winding arrangement matrix reaches the maximum initialization times, the current solution of the winding arrangement matrix is ​​used to update the optimal solution of the winding arrangement matrix, and the optimal solution is decoded to obtain the optimal fractional pole-to-path ratio winding arrangement scheme.

2. The fractional pole-to-circuit ratio winding arrangement method for an AC motor according to claim 1, characterized in that: The process of constructing the slot electromotive force vector in step 1 is: Step 11, give the basic parameters of the AC motor: number of slots Z, number of pole pairs p, number of motor phases m, number of parallel branches a and number of harmonics k; Step 12: Calculate the electrical angle α between slots: Step 13, calculate the number of slots b per phase: Step 14: Calculate the slot electromotive force e of each slot s : e s =cos(s·α·k)+jsin(s·α·k) Where s is the slot number of the slot where the upper side of the fractional pole ratio winding coil is located; Step 15: Arrange the slot electromotive force vector E = [e1, e2, ..., e Z / m ] T .

3. The fractional pole-to-circuit ratio winding arrangement method for an AC motor according to claim 1, characterized in that: The process of obtaining fitness in step 2 is: Step 2a1, initializing the winding arrangement matrix to obtain the winding arrangement matrix A; Step 2a2: Calculate the branch circuit composite slot electromotive force E b : AND b =A·E Step 2a3: Calculate E b The amplitude and phase of each element in is based on E b The amplitude and phase of each element in the calculation of amplitude asymmetry and phase asymmetry: Where ΔE is the amplitude asymmetry, Δδ is the phase asymmetry, and E b_mag The electromotive force vector E of the combined slot is b The vector composed of the amplitudes of each element in E b_pha The electromotive force vector E of the combined slot is b The vector composed of the phases of each element in; Step 2a4, the fitness f is obtained as follows: f=W m ·D.E 2 +W δ ·Dd 2 Where W m is the amplitude asymmetry weight, W δ is the phase asymmetry weight.

4. The fractional pole-to-circuit ratio winding arrangement method for an AC motor according to claim 3, characterized in that: In step 2, the winding arrangement matrix is ​​initially encoded, and the encoding process is as follows: Step 2b1, using the number of fractional pole-to-circuit ratio winding branches a and the number of positive phase belt slots b of a certain phase as the number of rows and columns to generate the positive phase belt winding arrangement matrix A + , ensure that there are only "0" elements and "1" elements in the matrix, and the number of "1" elements in each row is the same, and each column has only one "1" element; Step 2b2, copy the positive phase winding arrangement matrix A + Get the negative phase winding arrangement matrix A - The positive and negative phase winding arrangement matrices are formed into a winding arrangement matrix element set G with row vectors as basic elements; Step 2b3, combine the basic elements in the winding arrangement matrix element set G in pairs to obtain a winding arrangement matrix A with the number of rows being the number of winding branches a and the number of columns being a certain corresponding number of slots Z / m.

5. The fractional pole-to-circuit ratio winding arrangement method for an AC motor according to claim 1, characterized in that: The method for generating the neighborhood solution of the winding arrangement matrix in step 3 is to perform pairwise combinations of any basic elements in the winding arrangement matrix element set.

6. The fractional pole-to-circuit ratio winding arrangement method for an AC motor according to claim 1, characterized in that: The early stopping condition in step 3 is: the number of times the neighborhood solution is generated reaches the maximum number of consecutive unimproved iterations; if the early stopping condition is met, the winding arrangement matrix is ​​reinitialized and step 3 is executed again.

7. The fractional pole-to-circuit ratio winding arrangement method for an AC motor according to claim 4, characterized in that: The triggering condition for updating the optimal solution of the winding arrangement matrix using the current solution of the winding arrangement matrix in step 4 is any of the following conditions: Condition 1: ΔE and Δδ are satisfied at the same time: the current amplitude asymmetry ΔE is less than the amplitude asymmetry target threshold, and the current phase asymmetry Δδ is less than the phase asymmetry target threshold; Condition 2: The winding arrangement matrix reaches the maximum number of initialization times.

8. The fractional pole-to-circuit ratio winding arrangement method for an AC motor according to claim 7, characterized in that: The target threshold for amplitude asymmetry was set to 0.5%, and the target threshold for phase asymmetry was set to 0.5°.

9. The fractional pole-to-circuit ratio winding arrangement method for an AC motor according to claim 1, characterized in that: In step 4, the optimal solution is decoded to obtain the optimal fractional pole-to-path ratio winding arrangement scheme. The decoding process includes: Step 41, calculating the number of rows of the optimal solution of the winding arrangement matrix A and the number of "1" elements in each row, so as to determine the number of rows a and the number of columns N of the winding arrangement matrix B after decoding; Step 42, obtaining the column index of the "1" element in each row of the winding arrangement matrix A, and determining the phase band and corresponding slot number to which the column vector belongs according to the column index; Step 43, assign the slot numbers corresponding to the column vectors of the winding arrangement matrix A to the decoded winding arrangement matrix B in row order to obtain a single-phase winding arrangement scheme; Step 44: The arrangement rules of the remaining phase windings are the same as that of the single-phase winding, thereby obtaining an optimal fractional pole-to-circuit ratio winding arrangement scheme.

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