Distribution factor and average torque design method of motor with double three-phase winding units

Abstract

The invention discloses a distribution factor and average torque design method for a dual three-phase winding unit motor, which comprises the following steps: when the slot number and the phase shift angle of the dual three-phase motor meet Z / (12GCD (K, d)) and the result is an integer, expressing a slot potential star-shaped vector diagram arrangement rule under the configuration through a formula, and establishing a relation between a slot potential star-shaped vector diagram and a slot vector star diagram; and the winding arrangement of the double-three-phase winding unit motor under different phase shift angles is regular. Meanwhile, the obtained distribution factor of the motor with the double three-phase winding units follows the general rule that the distribution factor reaches the maximum value when the phase shift is 30 degrees, and the distribution factors under other phase shift angles are symmetrical about the 30-degree phase shift. Unified calculation of the distribution factors of the dual three-phase winding unit motor is realized, a general rule of the distribution factors is obtained, a theoretical basis is provided for permanent magnet motor distribution factor calculation and space harmonic analysis, and a design scheme is provided for improving the distribution factors and the average torque of the dual three-phase winding unit motor.

Description

Technical Field

[0001] This invention belongs to the field of electromagnetic performance calculation technology for permanent magnet motors, and particularly relates to a method for designing the distribution factor and average torque of a dual three-phase winding unit motor. Background Technology

[0002] The distribution factor directly characterizes the magnitude of the distributed effect in a dual-three-phase winding permanent magnet motor. It not only centrally reflects the electromagnetic performance of the permanent magnet motor but also forms the basis for calculating winding factors and analyzing magnetomotive force harmonics. Typically, calculating the distribution factor requires the use of a slot vector star diagram. Specifically, based on the principle of maximizing the synthetic magnetomotive force, the slot vectors formed by all coils belonging to one phase are vector-superimposed, and then compared with their algebraic sum to obtain the distribution factor. However, the slot vector star diagrams of a single-unit motor vary greatly due to the diversity of slot-pole combinations. Furthermore, even with the same slot-pole combination, the winding structure of a dual-three-phase motor can be altered by changing the phase shift angle, thus affecting the slot vector star diagram. In addition, the slot vector star diagrams for different harmonic orders of the same single-unit motor are also different. These factors significantly increase the difficulty of calculating the distribution factor. Moreover, there is currently a lack of unified calculation methods for the distribution factor of a dual-three-phase winding single-unit motor under different phase shift angles, failing to establish a relationship between the distribution factor and the phase shift angle. Summary of the Invention

[0003] Purpose of the Invention: The purpose of this invention is to provide a design method for the distribution factor and average torque of a dual three-phase winding unit motor. This lays a solid theoretical foundation for harmonic analysis and low-harmonic design of the magnetomotive force of dual three-phase permanent magnet motor windings, and provides a design scheme for improving the distribution factor and average torque of dual three-phase unit motors.

[0004] Technical solution: The present invention provides a method for designing the distribution factor and average torque of a dual three-phase winding unit motor, comprising the following steps:

[0005] Step 1: Determine the motor slot-pole fit and assess the feasibility of calculating the required phase shift angle;

[0006] Step 2: Determine the arrangement rules of the positive phase band of phase A1 in the star vector diagram of the slot potential based on the number of motor slots and the phase shift angle;

[0007] Step 3: Sort in ascending order based on the arrangement rules, corresponding to A1 in sequence. + 1, A1 + 2, A1 + 3……A1 + Z / 12 This refers to the arrangement order of the positive phase band of phase A1 in the star-shaped vector diagram of the slot potential;

[0008] Step 4: Convert the arrangement order into the corresponding slot number a1 in the slot star diagram. + j ;

[0009] Step 5, according to A1 + j With A1 + (1-j+Z / 12) The principle of synthesis is to calculate a1 corresponding to the slot star diagram. + j With a1 + (1-j+Z / 12) Spacing Δn j ;

[0010] Step 6: Place the corresponding slot number a1 in the slot star diagram. + j They were redirected to the same synthetic direction;

[0011] Step 7: Calculate the distribution factor of the vth harmonic under different phase shift angles of the double three-phase winding unit motor;

[0012] Step 8: After obtaining the distribution factor, the distribution factor of the double three-phase winding unit motor with the same slot pole combination is the largest when the phase shift is 30°, and the distribution factor at other phase shift angles is symmetrical about the 30° phase shift. The average torque is designed by selecting the winding structure with a 30° phase shift.

[0013] Furthermore, step 1 specifically involves: after determining the motor slot-pole fit, determining whether the required phase shift angle calculation is feasible:

[0014]

[0015] In the formula, K is the ratio of the phase shift angle Δ to the angle α0 between two adjacent vectors in the slot potential star vector diagram, Z is the number of slots in the motor, α0=2π / Z, d represents the number of slots occupied by each phase winding, which is one-sixth of Z in a double three-phase motor, GCD represents finding the greatest common divisor, and mod is the remainder after calculation.

[0016] Furthermore, Z is an integer multiple of 12.

[0017] Furthermore, step 2 specifically involves: determining the arrangement rules of the positive phase band of phase A1 in the slot potential star vector diagram based on the number of motor slots and the phase shift angle.

[0018] f(m,n)=1+2Bm+n,m∈{0,1,2…N-1},n∈{0,1,2…B-1} (2)

[0019] In the formula, N is the ratio of L to B, and B represents the number of positive phase band connections in phase A1 winding, specifically expressed as:

[0020] B = GCD(K,L) (3)

[0021] In the formula, L represents the number of slots in the positive phase of A1, which corresponds to Z / 12 in a dual three-phase motor.

[0022] Furthermore, step 4 specifically involves converting the arrangement order into the corresponding slot number a1 in the slot star diagram. + j :

[0023]

[0024] In the formula, S is the smallest natural number that makes the result of the formula an integer, and p is the pole logarithm.

[0025] Furthermore, step 5 specifically involves: according to A1 + j With A1 + (1-j+Z / 12) The principle of synthesis is to calculate a1 corresponding to the slot star diagram. + j With a1 + (1-j+Z / 12) Spacing Δn j :

[0026]

[0027] In the formula, It represents rounding up.

[0028] Furthermore, step 6 specifically involves converting the result calculated in formula (4) into a single synthesis direction:

[0029]

[0030] Furthermore, step 7 specifically involves: the formula for calculating the v-th harmonic distribution factor of the double three-phase winding unit motor under different phase shift angles is:

[0031]

[0032] Where v is the harmonic order, and C(j) is the vector composite eigenvalue, specifically expressed as follows: when Z is an even multiple of 12, C(j) is always 2; when Z is an odd multiple of 12, except... The value of C(j) is 1, and the values ​​of the rest of C(j) are 2.

[0033] The present invention also discloses a computer device, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the method of the present invention.

[0034] The present invention also discloses a computer-readable storage medium having a computer program / instructions stored thereon, which, when executed by a processor, implements the steps of the method of the present invention.

[0035] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages:

[0036] This invention establishes winding arrangement rules for different slot pole combinations under different phase shift angles, formalizes the slot potential star vector diagram, and establishes the relationship between the slot potential star vector diagram and the slot vector diagram. This reduces the dependence of the dual three-phase winding unit motor on the slot vector star diagram in calculating the distribution factor, thereby achieving unified calculation of the distribution factor of the dual three-phase winding unit motor and providing a theoretical basis for the calculation of the distribution factor and spatial harmonic analysis of dual three-phase permanent magnet motors. The research also shows that with a winding structure of 30° phase shift, the dual three-phase motor can achieve the maximum distribution factor, thus effectively improving the average torque. For example, in a 48-slot 22-pole dual three-phase motor, a 30° phase shift can increase the average torque by approximately 3.33% compared to 7.5°; in a 60-slot 58-pole dual three-phase motor, a 30° phase shift can increase the average torque by approximately 3.38% compared to 6°. This provides an effective design scheme for dual three-phase winding unit motors to maximize the distribution factor and achieve higher average torque. Attached Figure Description

[0037] Figure 1 This is a classification diagram of the characteristics of the dual three-phase winding unit motor of the present invention;

[0038] Figure 2 This is a schematic diagram of Embodiment 1 of the present invention, wherein (a) is a star-shaped vector diagram of the slot potential of a 60-slot 58-pole double three-phase motor with an 18° phase shift; and (b) is a star-shaped diagram of the slot potential of a 60-slot 58-pole double three-phase motor with an 18° phase shift.

[0039] Figure 3 This is a schematic diagram of Embodiment 2 of the present invention, wherein (a) is a star-shaped vector diagram of the slot potential of a 48-slot 22-pole dual three-phase motor with a 15° phase shift; (b) is a star-shaped vector diagram of the slot potential of a 48-slot 22-pole dual three-phase motor with a 15° phase shift; (c) is a star-shaped vector diagram of the slot potential of a 48-slot 22-pole dual three-phase motor with a 22.5° phase shift; and (d) is a star-shaped vector diagram of the slot potential of a 48-slot 22-pole dual three-phase motor with a 22.5° phase shift.

[0040] Figure 4 This is a schematic diagram of Embodiment 3 of the present invention, wherein (a) is the distribution factor of the 48-slot double three-phase winding unit motor; and (b) is the average torque of the 48-slot 22-pole motor with 7.5° and 30° phase shifts. Detailed Implementation

[0041] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0042] A method for calculating the distribution factor of a double three-phase winding unit motor under different phase shift angles includes the following steps:

[0043] The first step is to determine the motor slot-pole fit and whether the required phase shift angle calculation is feasible:

[0044]

[0045] In the formula, K is the ratio of the phase shift angle Δ to the angle α0 between two adjacent vectors in the slot potential star vector diagram, Z is the number of slots in the motor, α0=2π / Z, d represents the number of slots occupied by each phase winding, which is one-sixth of Z in a double three-phase motor, GCD represents finding the greatest common divisor, and mod is the remainder after calculation.

[0046] The second step is to determine the arrangement rules of the positive phase band of phase A1 in the star vector diagram of the slot potential based on the number of motor slots and the phase shift angle:

[0047] f(m,n)=1+2Bm+n,m∈{0,1,2…N-1},n∈{0,1,2…B-1} (2)

[0048] In the formula, N is the ratio of L to B, and B represents the number of positive phase band connections in phase A1 winding, specifically expressed as:

[0049] B = GCD(K,L) (3)

[0050] In the formula, L represents the number of slots in the positive phase of A1, which corresponds to Z / 12 in a dual three-phase motor;

[0051] The third step is to sort the results obtained in equation (2) in ascending order and then assign them to A1 accordingly. + 1, A1 + 2, A1 + 3……A1 + Z / 12 This refers to the arrangement order of the positive phase band of phase A1 in the star-shaped vector diagram of the slot potential;

[0052] The fourth step is to convert the arrangement order into the corresponding slot number a1 in the slot star diagram. + j :

[0053]

[0054] In the formula, S is the smallest natural number that makes the result of the formula an integer, and p is the pole logarithm;

[0055] Fifth step, according to A1 + j With A1 + (1-j+Z / 12) The principle of synthesis is to calculate a1 corresponding to the slot star diagram. + j With a1 + (1-j+Z / 12) Spacing Δn j :

[0056]

[0057] In the formula, It represents rounding up;

[0058] Step 6: Convert the results calculated in formula (4) to the same synthesis direction:

[0059]

[0060] Step 7: The formula for calculating the distribution factor of the v-th harmonic under different phase shift angles of the double three-phase winding unit motor is as follows:

[0061]

[0062] Where v is the harmonic order, and C(j) is the vector composite eigenvalue, specifically expressed as follows: when Z is an even multiple of 12, C(j) is always 2; when Z is an odd multiple of 12, except... The value of C(j) is 1, and the values ​​of the rest of C(j) are 2.

[0063] Step 8: After obtaining the distribution factor, the distribution factor of the double three-phase winding unit motor with the same slot pole combination is the largest when the phase shift is 30°, and the distribution factor at other phase shift angles is symmetrical about the 30° phase shift. The average torque is designed by selecting the winding structure with a 30° phase shift.

[0064] Reference Figure 1 Based on the parity of Z / 12 of the double three-phase winding unit motor, it can be divided into two types. The winding arrangement of the double three-phase winding unit motor of these two types will be explained next.

[0065] Example 1

[0066] Reference Figure 2 , Figure 2 This section presents the star-shaped vector diagram of the slot potential of a first-class double three-phase winding unit motor and its corresponding slot vector star diagram, using a 60s58p slot pole configuration. Since it is a unit motor with an odd number of slots (12), it can only achieve a phase shift angle Δ that is an odd multiple of the slot pitch angle α0. Taking an 18° phase shift as an example, according to step two, the arrangement order of the positive phase band vectors of phase A1 in the slot potential star-shaped vector diagram is: 1, 3, 5, 7. The corresponding slot numbers in the slot vector star diagram are: 1, 59, 57, 55, 53. Substituting these into step five, the calculated spans between the synthesized vectors are: 52, 4, 0. In step six, the spans are converted to the same direction: γ1 = 0, γ2 = 1, γ3 = 1. Substituting these into step seven, the distribution factor of the vth harmonic can be obtained.

[0067] Example 2

[0068] Reference Figure 3 , Figure 3 This section presents the slot potential star vector diagram and its corresponding slot vector star diagram for a type II double three-phase winding unit motor, using a 48s22p slot pole configuration. Since it is a unit motor with an even number of slots (12), it can achieve phase shift angles Δ that are odd or even multiples of the slot pitch angle α0, with two cases depending on the odd / even relationship. Taking 15° and 22.5° phase shift angles as examples: At a 15° phase shift, according to step two, the order of the positive phase band vectors of phase A1 in the slot potential star vector diagram is: 1, 2, 5, 6. The corresponding slot numbers in the slot vector star diagram are: 1, 36, 45, 32. Substituting these into step five, the calculated spans between the synthesized vectors are 31 and 9, respectively. In step six, the spans are converted to the same direction, γ1 = 0 and γ2 = 1. With a 22.5° phase shift, according to step two, the order of the positive phase band vectors of phase A1 in the slot potential star vector diagram is: 1, 3, 5, 7. These correspond to slot numbers 1, 23, 45, 19 in the slot vector star diagram. Substituting these values ​​into step five, the calculated spans between the synthesized vectors are 18 and 22. In step six, the spans are converted to the same direction, γ1 = 0 and γ2 = 1. Substituting these values ​​into step seven, the distribution factor of the vth harmonic can be obtained.

[0069] Example 3

[0070] Reference Figure 4 The formula was applied to calculate the first harmonic distribution factor of the 48-slot winding under different pole pairs and phase shift angles, and the average torque of the 48-slot 22-pole winding with a phase shift of 7.5° and 30° was compared. As shown in the figure, the winding factor is largest at a phase shift of 30°, and other phase shift angles are symmetrical about 30°. Furthermore, the average torque at a phase shift of 30° is significantly greater than that at a phase shift of 7.5°.

[0071] In summary, the method for calculating the distribution factor of this dual-three-phase winding unit motor under different phase shift angles establishes winding arrangement rules for different slot pole combinations and phase shift angles, specifically representing the winding arrangement through formulas. Simultaneously, this process reveals that the distribution factor of the dual-three-phase winding unit motor follows the general rule that "the distribution factor reaches its maximum value at a phase shift of 30°, and the distribution factor at other phase shift angles is symmetrical about the 30° phase shift." This achieves a unified calculation of the distribution factor of the dual-three-phase winding unit motor, derives the general rules of the distribution factor, provides a theoretical basis for the calculation of the distribution factor of permanent magnet motors and spatial harmonic analysis, and also provides a design scheme for maximizing the distribution factor and improving the average torque of the dual-three-phase winding unit motor.

[0072] The embodiments of the present invention have been described in detail above, but the content described is only a preferred embodiment of the present invention and should not be considered as limiting the scope of the present invention. All equivalent changes and improvements made in accordance with the scope of the present invention should still fall within the patent coverage of the present invention.

Claims

1. A method for designing the distribution factor and average torque of a dual three-phase winding unit motor, characterized in that, Includes the following steps: Step 1: Determine the motor slot-pole fit and assess the feasibility of calculating the required phase shift angle; Step 2: Determine the arrangement rules of the positive phase band of phase A1 in the star vector diagram of the slot potential based on the number of motor slots and the phase shift angle; Step 3: Sort in ascending order based on the arrangement rules, corresponding to the following in sequence. This refers to the arrangement order of the positive phase band of phase A1 in the star-shaped vector diagram of the slot potential; Step 4: Convert the arrangement order into the corresponding slot number in the slot star diagram. Step 5, according to and The principle of synthesis is to calculate the corresponding slot star diagram. and Spacing Δn j ; Step 6: Match the corresponding slot number in the slot star diagram. They were redirected to the same synthetic direction; Step 7: Calculate the distribution factor of the vth harmonic under different phase shift angles of the double three-phase winding unit motor; Step 8: After obtaining the distribution factor, the distribution factor of the double three-phase winding unit motor with the same slot pole combination is the largest when the phase shift is 30°, and the distribution factor at other phase shift angles is symmetrical about the 30° phase shift. The average torque is designed by selecting the winding structure with a 30° phase shift.

2. The method for designing the distribution factor and average torque of a double three-phase winding unit motor according to claim 1, characterized in that, Step 1 specifically involves: After determining the motor slot-pole fit, judging whether the required phase shift angle calculation is feasible. In the formula, K is the ratio of the phase shift angle Δ to the angle α0 between two adjacent vectors in the slot potential star vector diagram, Z is the number of slots in the motor, α0=2π / Z, d represents the number of slots occupied by each phase winding, which is one-sixth of Z in a double three-phase motor, GCD represents finding the greatest common divisor, and mod is the remainder after calculation.

3. The method for designing the distribution factor and average torque of a double three-phase winding unit motor according to claim 2, characterized in that, Z is an integer multiple of 12.

4. The method for designing the distribution factor and average torque of a double three-phase winding unit motor according to claim 2, characterized in that, Step 2 specifically involves determining the arrangement rules of the positive phase band of phase A1 in the slot potential star vector diagram based on the number of motor slots and the phase shift angle. f(m,n)=1+2Bm+n,m∈{0,1,2…N-1},n∈{0,1,2…B-1} (2) In the formula, N is the ratio of L to B, and B represents the number of positive phase band connections in phase A1 winding, specifically expressed as: B = GCD(K,L) (3) In the formula, L represents the number of slots in the positive phase of A1, which corresponds to Z / 12 in a dual three-phase motor.

5. The method for designing the distribution factor and average torque of a double three-phase winding unit motor according to claim 4, characterized in that, Step 4 specifically involves converting the arrangement order into the corresponding slot number in the slot star diagram. In the formula, S is the smallest natural number that makes the result of the formula an integer, and p is the pole logarithm.

6. The method for designing the distribution factor and average torque of a double three-phase winding unit motor according to claim 5, characterized in that, Step 5 specifically involves: according to and The principle of synthesis is to calculate the corresponding slot star diagram. and Spacing Δn j : In the formula, It represents rounding up.

7. The method for designing the distribution factor and average torque of a double three-phase winding unit motor according to claim 6, characterized in that, Step 6 specifically involves converting the result calculated in formula (4) into a single synthesis direction:

8. The method for designing the distribution factor and average torque of a double three-phase winding unit motor according to claim 7, characterized in that, Step 7 specifically involves the following: The formula for calculating the v-th harmonic distribution factor of a double three-phase winding unit motor under different phase shift angles is: Where v is the harmonic order, and C(j) is the vector composite eigenvalue, specifically expressed as follows: when Z is an even multiple of 12, C(j) is always 2; when Z is an odd multiple of 12, except... The value of C(j) is 1, and the values ​​of the rest of C(j) are 2.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory, characterized in that, The processor executes the computer program to implement the steps of the method of claim 1.

10. A computer-readable storage medium having a computer program / instructions stored thereon, characterized in that, When the computer program / instructions are executed by the processor, they implement the steps of the method of claim 1.

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