Method, device and medium for evaluating symmetry of large integer-slot generator stator winding branch potential

Abstract

The application discloses a symmetry evaluation method, device and medium for branch potential of a large integer-slot generator stator winding, relates to the technical field of generators, and aims at solving the problem of how to evaluate the symmetry of branch potential of a large integer-slot generator stator winding. Z With 2 p Calculations α With q ; according to N Establish SW , record the three-phase stator coil connection sequence and phase belt attributes, according to q Assign SW the phase belt attributes of each coil; based on α and the wiring information, calculate the three-phase potential of each branch, and store the virtual and real parts in the potential data structure; rotate the A-phase branch potential as a whole by θ i angle so that the end coincides with the positive x axis, and the B-phase and C-phase are rotated by θ i +240° and θ i +120° respectively, and store the results after rotation in EA_R , EB_R and EC_R ; calculate the difference between the potential values in the A-phase branches and the B-phase and C-phase, and construct SIM ; judge SIM whether there is a symmetrical branch combination meeting the conditions, if there is, store the number in Sym ; if Sym the number of rows is equal to N , it is determined that symmetry is possessed, otherwise, it is determined that asymmetry is possessed.

Description

Technical Field

[0001] This invention discloses a method, equipment, and medium for evaluating the symmetry of the branch potential of the stator winding of a large integer slot generator, relating to the field of generator technology. Background Technology

[0002] Large generators are core equipment in power systems, and their operational reliability directly affects power quality, continuous power supply to users, and the safety and stability of the entire power grid. Among various generator faults, single-phase grounding faults in the stator winding are the most common. To ensure the safe operation of large generators, fundamental zero-sequence voltage type stator grounding protection is typically configured. Under normal operating conditions, the generator displacement voltage is generally small, with its secondary measurement value typically around 0.5V. However, in recent years, some generator sets in China have exhibited significantly higher displacement voltages during actual operation. To mitigate the impact of displacement voltage on the protection system, it has become necessary to increase the setting value of the fundamental zero-sequence voltage protection, resulting in a dead zone in the protection range and posing a potential threat to the safe operation of the unit.

[0003] Currently, regarding the problem of excessive displacement voltage in large generators, scholars both domestically and internationally have analyzed the displacement voltage using parametric circuit models with lumped capacitance or quasi-distributed capacitance. They have identified three key factors influencing the displacement voltage: the symmetry of the generator's three-phase electromotive forces, the balance of the three-phase capacitance to ground, and the neutral point grounding method. Specifically, the neutral point grounding method does not determine the existence of displacement voltage, but only affects its amplitude; the consistency of the three-phase capacitance to ground and the uniformity of the three-phase distributed capacitance directly relate to the existence of displacement voltage; similarly, the symmetry of the three-phase electromotive forces and the three-phase branch electromotive forces also directly affects the presence or absence of displacement voltage.

[0004] In the manufacturing process of large generators, the three-phase-to-ground capacitance is mainly affected by the characteristics of the generator's structural materials, and its consistency and uniformity are difficult to control precisely. In contrast, the composition of the three-phase branch potentials depends on the branch connection sequence of the stator windings, and can be artificially adjusted during the generator design and production stages. However, current research on improving the symmetry of the potential composition by optimizing the branch connection is insufficient, especially lacking a systematic and reliable method for evaluating the symmetry of the stator winding branch potential composition. Summary of the Invention

[0005] This invention addresses the problems in existing technologies by providing a method, equipment, and medium for evaluating the symmetry of the branch potential composition of the stator windings in large integer slot generators. Utilizing design parameters such as stator winding wiring information, the composition of the three-phase branch potentials can be quickly obtained. Through potential rotation and similarity matching, the symmetry of the stator winding branch potential composition can be accurately evaluated. This provides effective criteria for generator design and winding wiring optimization, helping to suppress displacement voltage at its source and improve unit operational safety.

[0006] To achieve the above-mentioned objectives, the technical solution of the present invention is as follows: A method for evaluating the symmetry of the branch potentials in the stator windings of a large integer-slot generator, firstly based on the number of stator slots... Z With extreme logarithm 2 p Calculate the slot spacing angle α Number of slots per pole per phase q Subsequently, based on the number of parallel branches N Establish branch wiring information data structure SW Each branch corresponds to one L A 6×6 matrix records the connection sequence and phase band attributes of the three-phase stator coils, and then based on the number of slots per pole and per phase. q Assigning data structure SW The phase band properties of each coil; further based on the slot pitch angle. α The three-phase potential of each branch is calculated based on the wiring information, and the virtual and real potentials are separated and stored in the potential data structure. BRE Next, rotate the potential of each branch of phase A as a whole. θ i Angle so that its end is perpendicular to the positive angle x When the axes coincide, the corresponding axes B and C rotate. θ i +240° and θ i After rotating by +120°, the results are stored separately. EA_R , EB_R and EC_R Based on this, the differences between all potential values ​​in each branch of phase A and phases B and C are calculated sequentially, and a similarity data structure is constructed. SIM ; and then judge SIM If a symmetric branch combination exists that meets the conditions, then its number is stored in the symmetric branch potential matrix. Sym Finally, if Sym The number of branches equals the total number of branches. N If the potential of the generator stator winding branch is good, it is determined that the potential is symmetrical; otherwise, it is asymmetrical.

[0007] Preferably, it includes the following steps: Step S1: Utilize the number of generator stator slotsZ With extreme logarithms 2p Calculate the slot spacing angle α Number of slots per pole per phase q ; Step S2: Based on the number of parallel branches of the stator winding N ,Establish N Branch wiring information data structure of the row SW ; Step S3: Set the data structure SW The Middle i ( i =1,2,…, N ) matrices SW { i}for L A 6-row, 6-column numerical matrix used to store the first... i The connection sequence of the three-phase stator coils of each branch and their phase band attributes; among which, L The total number of branch coils is represented by the matrix. Columns 1, 3, and 5 record the connection order of the three-phase stator coils A, B, and C from the neutral point side, respectively. Columns 2, 4, and 6 represent the phase band attributes of the corresponding coils, which are initially set to 0. Step S4, based on the matrix SW { i} and the number of slots per pole per phase q Each coil is assigned a corresponding phase band attribute; Step S5, based on the matrix SW { i} and slot pitch angle α Calculate the first i The three-phase potential values ​​at the ends of each coil in the branch are stored in the potential data structure after separating the real and virtual values. BRE Matrix in BRE { i}; Step S6: Calculate the first phase of phase A sequentially. i Terminal potential of the branch BRE { i}( L ,1:2) Tongzheng x Angle between axes θ i And thus rotate all its potential values ​​clockwise. θ i Angle, so that the end is perpendicular to the positive angle. x With axes aligned, the potential values ​​of each branch after rotation are stored in a rotating potential data structure. EA_R; Step S7, similarly, phases B and C are... i All potential values ​​of the branches rotate clockwise θ i +240° and θi +120°, and store the rotated potential value in the data structure. EB_R and EC_R ; Step S8: Calculate the first phase of phase A sequentially. i The differences between the potential values ​​of all branches in phase B and phase C and the potential values ​​of all branches in phase C, and the difference in error capacity. err In this case, construct a similarity data structure SIM ; Step S9: Determine the similarity data structure SIM The Middle i matrix SIM { i If the sum of the elements in the two rows is greater than 1, then extract the column index of the first non-zero element in each row. N bi and N ci , the triple [ i , N bi , N ci Store the symmetric branch potential matrix Sym At the same time, all subsequent matrices SIM { i +1:end} is located in (1, N bi ) and (2, N ci The elements are cleared to zero; Step S10: Obtain the symmetric branch potential matrix Sym number of rows SNUM ,like SNUM = N If the branch potential of the generator stator winding is well symmetrical, then it is considered that the branch potential of the generator stator winding exhibits good symmetry; otherwise, it is asymmetrical.

[0008] Preferably, in step S1, the slot pitch angle α and the number of slots per pole per phase q As shown in the following formula: ; .

[0009] Preferably, in step S4, the corresponding phase band attribute of each coil is described as follows: ; in, for Divide by The remainder, For the first i Branch number k Mutually(k =1 represents phase A. k =2 represents phase B. k =3 represents the C phase) in the first j The slot number of the root coil, i.e., the data structure SW The Middle i matrix SW { i} j line (2) k -1) Column element values; For the first i Branch number k The first j The phase band properties of the root coil, i.e., the data structure. SW The Middle i matrix SW { i} j OK 2k Column element values.

[0010] Preferably, in step S5, the matrix... BRE { i The expression for calculating} is: ; in, For the first i Branch number k The phase difference between the j-th coil in phase A and the first coil in phase A; For the first i The slot number of the first coil in phase A of branch A, i.e., the data structure. SW The Middle i matrix SW { i The value of the element in the first row and first column of}; For the first i Branch number k The first j The potential of +1 coil; For the first i Branch number k The first j The potential of the root coil; For the first i Branch number k The real part of the phase coil potential, i.e., the matrix BRE { i} second k -1 column contains all element values; For the first i Branch number k The imaginary part of the phase coil potential, i.e., the matrix BRE { i} secondk List all element values; For the first i Branch number k The potential of all coils in a phase.

[0011] Preferably, in step S6, the rotating potential data structure EA_R The calculation expression is: ; in, For the first i The imaginary part of the potential of the coil at the end of phase A of the branch, i.e., the matrix BRE { i}No. L The value of the element in the second column of the row; For the first i The real part of the coil potential at the end of phase A of the branch, i.e., the matrix BRE { i}No. L The value of the element in the first column of the row; For the first i Branch A, Phase A j The imaginary part of the potential of the root coil, i.e., the matrix BRE { i}No. j The value of the element in the second column of the row; For the first i Branch A, Phase A j The real part of the potential of the root coil, i.e., the matrix BRE { i}No. j The value of the element in the first column of the row; For the first rotation i Branch A phase number j The real part of the root coil potential, i.e., the rotating potential data structure. EA_R The Middle i The first matrix j The value of the element in row 1 and column 1; For the first rotation i Branch A phase number j The imaginary part of the root coil potential, i.e., the rotating potential data structure. EA_R The Middle i The first matrix j The value of the element in row 2 and column 2.

[0012] Preferably, in step S7, the data structure EB_R and EC_R The calculation expression is: ; in, For the first i Branch B phasej The real part of the potential of the root coil, i.e., the matrix BRE { i}No. j The value of the element in the third column of the row; For the first i Branch B phase j The imaginary part of the potential of the root coil, i.e., the matrix BRE { i}No. j The value of the element in the 4th column of the row; For the first rotation i Branch B phase j The real part of the root coil potential, i.e., the rotating potential data structure. EB_R The Middle i The first matrix j The value of the element in row 1 and column 1; For the first rotation i Branch B phase j The imaginary part of the root coil potential, i.e., the rotating potential data structure. EB_R The Middle i The first matrix j The value of the element in row 2 and column 2; For the first i Branch C phase j The real part of the potential of the root coil, i.e., the matrix BRE { i}No. j The value of the element in the 5th column of the row; For the first i Branch C phase j The imaginary part of the potential of the root coil, i.e., the matrix BRE { i}No. j The value of the element in the 6th column of the row; For the first rotation i Branch C phase j The real part of the root coil potential, i.e., the rotating potential data structure. EC_R The Middle i The first matrix j The value of the element in row 1 and column 1; For the first rotation i Branch C phase j The imaginary part of the root coil potential, i.e., the rotating potential data structure. EC_R The Middle i The first matrix j The value of the element in row 2 and column 2.

[0013] Preferably, in step S8, the similarity data structure SIM The calculation expression is: ; Among them, elements MB n For phase B n The real and imaginary parts of the potential of each coil in the branch are related to the first phase of A. i The maximum difference in amplitude between the real and imaginary parts of the potential of each coil in the branch potential; element MC n For phase C n The real and imaginary parts of the potential of each coil in the branch are related to the first phase of A. i The maximum difference in amplitude between the real and imaginary parts of the potential of each coil in the branch potential; For the first rotation i The real and imaginary parts of the electromotive force of all coils in phase A of branch A, i.e., the rotating electromotive force data structure. EA_R The Middle i A matrix; For the first rotation n The real and imaginary parts of the electromotive force of all coils in phase B of the branch, i.e., the rotating electromotive force data structure. EB_R The Middle n A matrix; For the first rotation n The real and imaginary parts of the electromotive force of all coils in phase C of a branch, i.e., the rotating electromotive force data structure. EC_R The Middle n A matrix; For phase B n Branch potential and phase A i The similarity of branch potentials, i.e., similarity data structure. SIM The Middle i The first row of the matrix n Column element values; For phase C n Branch potential and phase A i The similarity of branch potentials, i.e., similarity data structure. SIM The Middle i The second row of the matrix n Column element values.

[0014] An apparatus includes a display device, a processor, a memory, and program instructions and operation modules stored in the memory and executable on the processor, wherein the processor executes the program instructions and operation modules to implement the method described above.

[0015] A medium, a computer-readable storage medium, stores computer instructions that cause a computer to perform the methods described above.

[0016] The beneficial effects of this invention are: The symmetry evaluation method for the branch potential of the stator winding of a large integer slot generator provided by this invention can complete the symmetry evaluation during the generator design stage. It only relies on inherent parameters such as the winding connection sequence and slot pitch angle, resulting in low evaluation cost, high efficiency, and no limitation by on-site operating conditions.

[0017] Second, the symmetry evaluation method for the branch potential of the stator winding of a large integer slot generator provided by this invention introduces a potential rotation and similarity matching algorithm to construct a quantitative symmetry criterion, transforming the abstract "symmetry" problem into precise numerical calculation and logical judgment. The method is rigorous and reliable, effectively avoiding the subjectivity of traditional experience judgment.

[0018] Third, the symmetry evaluation method for the branch potential of the stator winding of a large integer slot generator provided by the present invention can accurately identify the three-phase branch combination that meets the symmetry requirements. It can be used to guide the optimized design and wiring arrangement of the generator stator winding, which helps to suppress the problem of excessive displacement voltage caused by potential asymmetry from the root, and improves the inherent safety and operational reliability of the generator. Attached Figure Description

[0019] Figure 1 This is a flowchart of the present invention. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to embodiments, but the implementation of the present invention is not limited thereto.

[0021] Example 1 like Figure 1 As shown, the symmetry evaluation method for the branch potential of the stator winding of a large integer slot generator is first based on the number of stator slots. Z With extreme logarithm 2 p Calculate the slot spacing angle α Number of slots per pole per phase q Subsequently, based on the number of parallel branches N Establish branch wiring information data structure SW Each branch corresponds to one L A 6×6 matrix records the connection sequence and phase band attributes of the three-phase stator coils, and then based on the number of slots per pole and per phase. q Assigning data structure SW The phase band properties of each coil; further based on the slot pitch angle. α The three-phase potential of each branch is calculated based on the wiring information, and the virtual and real potentials are separated and stored in the potential data structure. BRE Next, rotate the potential of each branch of phase A as a whole. θ i Angle so that its end is perpendicular to the positive angle x When the axes coincide, the corresponding axes B and C rotate. θi +240° and θ i After rotating by +120°, the results are stored separately. EA_R , EB_R and EC_R Based on this, the differences between all potential values ​​in each branch of phase A and phases B and C are calculated sequentially, and a similarity data structure is constructed. SIM ; and then judge SIM If a symmetric branch combination exists that meets the conditions, then its number is stored in the symmetric branch potential matrix. Sym Finally, if Sym The number of branches equals the total number of branches. N If the potential of the generator stator winding branch is good, it is determined that the potential is symmetrical; otherwise, it is asymmetrical.

[0022] Example 2 like Figure 1 As shown, the symmetry evaluation method for the branch potential of the stator winding of a large integer slot generator is first based on the number of stator slots. Z With extreme logarithm 2 p Calculate the slot spacing angle α Number of slots per pole per phase q Subsequently, based on the number of parallel branches N Establish branch wiring information data structure SW Each branch corresponds to one L A 6×6 matrix records the connection sequence and phase band attributes of the three-phase stator coils, and then based on the number of slots per pole and per phase. q Assigning data structure SW The phase band properties of each coil; further based on the slot pitch angle. α The three-phase potential of each branch is calculated based on the wiring information, and the virtual and real potentials are separated and stored in the potential data structure. BRE Next, rotate the potential of each branch of phase A as a whole. θ i Angle so that its end is perpendicular to the positive angle x When the axes coincide, the corresponding axes B and C rotate. θ i +240° and θ i After rotating by +120°, the results are stored separately. EA_R , EB_R and EC_R Based on this, the differences between all potential values ​​in each branch of phase A and phases B and C are calculated sequentially, and a similarity data structure is constructed. SIM ; and then judge SIM If a symmetric branch combination exists that meets the conditions, then its number is stored in the symmetric branch potential matrix. Sym Finally, if SymThe number of branches equals the total number of branches. N If the potential of the generator stator winding branch is good, it is determined that the potential is symmetrical; otherwise, it is asymmetrical.

[0023] This includes the following steps: Step S1: Utilize the number of generator stator slots Z With extreme logarithms 2p Calculate the slot spacing angle α Number of slots per pole per phase q ; Step S2: Based on the number of parallel branches of the stator winding N ,Establish N Branch wiring information data structure of the row SW ; Step S3: Set the data structure SW The Middle i ( i =1,2,…, N ) matrices SW { i}for L A 6-row, 6-column numerical matrix used to store the first... i The connection sequence of the three-phase stator coils of each branch and their phase band attributes; among which, L The total number of branch coils is represented by the matrix. Columns 1, 3, and 5 record the connection order of the three-phase stator coils A, B, and C from the neutral point side, respectively. Columns 2, 4, and 6 represent the phase band attributes of the corresponding coils, which are initially set to 0. Step S4, based on the matrix SW { i} and the number of slots per pole per phase q Each coil is assigned a corresponding phase band attribute. Step S5, based on the matrix SW { i} and slot pitch angle α Calculate the first i The three-phase potential values ​​at the ends of each coil in the branch are stored in the potential data structure after separating the real and virtual values. BRE Matrix in BRE { i}; Step S6: Calculate the first phase of phase A sequentially. i Terminal potential of the branch BRE { i}( L ,1:2) Tongzheng x Angle between axes θ i And thus rotate all its potential values ​​clockwise. θ i Angle, so that the end is perpendicular to the positive angle. xWith axes aligned, the potential values ​​of each branch after rotation are stored in a rotating potential data structure. EA_R; Step S7, similarly, phases B and C are... i All potential values ​​of the branches rotate clockwise θ i +240° and θ i +120°, and store the rotated potential value in the data structure. EB_R and EC_R ; Step S8: Calculate the first phase of phase A sequentially. i The differences between the potential values ​​of all branches in phase B and phase C and the potential values ​​of all branches in phase C, and the difference in error capacity. err In this case, construct a similarity data structure SIM ; Step S9: Determine the similarity data structure SIM The Middle i matrix SIM { i If the sum of the elements in the two rows is greater than 1, then extract the column index of the first non-zero element in each row. N bi and N ci , the triple [ i , N bi , N ci Store the symmetric branch potential matrix Sym At the same time, all subsequent matrices SIM { i +1:end} is located in (1, N bi ) and (2, N ci The elements are cleared to zero; Step S10: Obtain the symmetric branch potential matrix Sym number of rows SNUM ,like SNUM = N If the branch potential of the generator stator winding is well symmetrical, then it is considered that the branch potential of the generator stator winding exhibits good symmetry; otherwise, it is asymmetrical.

[0024] In step S1, the slot pitch angle α and the number of slots per pole per phase q As shown in the following formula: ; .

[0025] In step S4, the phase band attribute of each coil is described as follows: ; in, for Divide by The remainder, For the first i Branch number k Mutually( k =1 represents phase A. k =2 represents phase B. k =3 represents the C phase) in the first j The slot number of the root coil, i.e., the data structure SW The Middle i matrix SW { i} j line (2) k -1) Column element values; For the first i Branch number k The first j The phase band properties of the root coil, i.e., the data structure. SW The Middle i matrix SW { i} j OK 2k Column element values.

[0026] In step S5, the matrix... BRE { i The expression for calculating} is: ; in, For the first i Branch number k The phase difference between the j-th coil in phase A and the first coil in phase A; For the first i The slot number of the first coil in phase A of branch A, i.e., the data structure. SW The Middle i matrix SW { i The value of the element in the first row and first column of}; For the first i Branch number k The first j The potential of +1 coil; For the first i Branch number k The first j The potential of the root coil; For the first i Branch number k The real part of the phase coil potential, i.e., the matrix BRE{ i} second k -1 column contains all element values; For the first i Branch number k The imaginary part of the phase coil potential, i.e., the matrix BRE { i} second k List all element values; For the first i Branch number k The potential of all coils in a phase.

[0027] In step S6, the rotating potential data structure EA_R The calculation expression is: ; in, For the first i The imaginary part of the potential of the coil at the end of phase A of the branch, i.e., the matrix BRE { i}No. L The value of the element in the second column of the row; For the first i The real part of the coil potential at the end of phase A of the branch, i.e., the matrix BRE { i}No. L The value of the element in the first column of the row; For the first i Branch A, Phase A j The imaginary part of the potential of the root coil, i.e., the matrix BRE { i}No. j The value of the element in the second column of the row; For the first i Branch A, Phase A j The real part of the potential of the root coil, i.e., the matrix BRE { i}No. j The value of the element in the first column of the row; For the first rotation i Branch A phase number j The real part of the root coil potential, i.e., the rotating potential data structure. EA_R The Middle i The first matrix j The value of the element in row 1 and column 1; For the first rotation i Branch A phase number j The imaginary part of the root coil potential, i.e., the rotating potential data structure. EA_R The Middle i The first matrix j The value of the element in row 2 and column 2.

[0028] In step S7, the data structure EB_R and EC_R The calculation expression is: ; in, For the first i Branch B phase j The real part of the potential of the root coil, i.e., the matrix BRE { i}No. j The value of the element in the third column of the row; For the first i Branch B phase j The imaginary part of the potential of the root coil, i.e., the matrix BRE { i}No. j The value of the element in the 4th column of the row; For the first rotation i Branch B phase j The real part of the root coil potential, i.e., the rotating potential data structure. EB_R The Middle i The first matrix j The value of the element in row 1 and column 1; For the first rotation i Branch B phase j The imaginary part of the root coil potential, i.e., the rotating potential data structure. EB_R The Middle i The first matrix j The value of the element in row 2 and column 2; For the first i Branch C phase j The real part of the potential of the root coil, i.e., the matrix BRE { i}No. j The value of the element in the 5th column of the row; For the first i Branch C phase j The imaginary part of the potential of the root coil, i.e., the matrix BRE { i}No. j The value of the element in the 6th column of the row; For the first rotation i Branch C phase j The real part of the root coil potential, i.e., the rotating potential data structure. EC_R The Middle i The first matrix j The value of the element in row 1 and column 1; For the first rotation i Branch C phase j The imaginary part of the root coil potential, i.e., the rotating potential data structure. EC_R The Middle iThe first matrix j The value of the element in row 2 and column 2.

[0029] In step S8, the similarity data structure SIM The calculation expression is: ; Among them, elements MB n For phase B n The real and imaginary parts of the potential of each coil in the branch are related to the first phase of A. i The maximum difference in amplitude between the real and imaginary parts of the potential of each coil in the branch potential; element MC n For phase C n The real and imaginary parts of the potential of each coil in the branch are related to the first phase of A. i The maximum difference in amplitude between the real and imaginary parts of the potential of each coil in the branch potential; For the first rotation i The real and imaginary parts of the electromotive force of all coils in phase A of branch A, i.e., the rotating electromotive force data structure. EA_R The Middle i A matrix; For the first rotation n The real and imaginary parts of the electromotive force of all coils in phase B of the branch, i.e., the rotating electromotive force data structure. EB_R The Middle n A matrix; For the first rotation n The real and imaginary parts of the electromotive force of all coils in phase C of a branch, i.e., the rotating electromotive force data structure. EC_R The Middle n A matrix; For phase B n Branch potential and phase A i The similarity of branch potentials, i.e., similarity data structure. SIM The Middle i The first row of the matrix n Column element values; For phase C n Branch potential and phase A i The similarity of branch potentials, i.e., similarity data structure. SIM The Middle i The second row of the matrix n Column element values.

[0030] Example 3 Given that a certain integer slot generator has 2 pole pairs p =6, number of stator slots Z =72, number of slots per pole per phase q =4, 4 branches per phase ( N =4), 6 turns of coil per branch ( L =6).

[0031] S1. Calculate the slot spacing angle : S2. Based on the number of parallel branches of the stator windings N =4, establish a 4-row branch wiring information data structure. SW ; S3. Define the data structure SW The Middle i ( i =1,2,3,4) matrices SW { i} is a 6x6 numerical matrix used to store the first... i The connection sequence of the three-phase stator coils of each branch and their phase band attributes; wherein, the first, third and fifth columns of the matrix record the connection sequence of the three-phase stator coils A, B and C from the neutral point side, respectively, and the second, fourth and sixth columns are the phase band attributes of the corresponding coils, which are initially set to 0; ; ； ； ; S4. Based on the matrix SW { i} and the number of slots per pole per phase q =4, assigning each coil the corresponding phase band attribute; ; ; ; ; ; S5. Based on the matrix SW { i} and slot pitch angle α Calculate the first i The three-phase potential values ​​at the ends of each coil in the branch are stored in the potential data structure after separating the real and virtual values. BRE Matrix in BRE { i}; ; S6. Calculate the first phase of phase A sequentially. i Terminal potential of the branch BRE { i}(6,1:2)Tongzheng x Angle between axesθ i And thus rotate all its potential values ​​clockwise. θ i Angle, so that the end is perpendicular to the positive angle. x With axes aligned, the potential values ​​of each branch after rotation are stored in a rotating potential data structure. EA_R; ; Step S7, similarly, phases B and C are... i All potential values ​​of the branches rotate clockwise θ i +240° and θ i +120°, and store the rotated potential value in the data structure. EB_R and EC_R ; ; Step S8: Calculate the first phase of phase A sequentially. i The differences between the potential values ​​of all branches in phase B and phase C and the potential values ​​of all branches in phase C, and the error capacity. err Constructing a similarity data structure when the similarity is 0.0001. SIM ; ; get: ; ; ; ; Step S9: Determine the similarity data structure SIM The Middle i matrix SIM { i If the sum of the elements in the two rows is greater than 1, then extract the column index of the first non-zero element in each row. N bi and N ci , the triple [ i , N bi , N ci Store the symmetric branch potential matrix Sym At the same time, all subsequent matrices SIM { i +1:end} is located in (1, N bi ) and (2, N ci Clear the elements of ) to zero: ; Step S10: Obtain the symmetric branch potential matrix Sym number of rows SNUM =4, obviously SNUM = N If the branch potential of the generator stator winding is considered to exhibit good symmetry, then it is assumed that the branch potential of the generator stator winding exhibits good symmetry.

[0032] Example 4 Secondly, this embodiment provides a device including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the method described in Embodiment 2 above.

[0033] The processor can perform various appropriate actions and processes based on a program stored in read-only memory (ROM) or a program loaded from storage into random access memory (RAM). The processor may include, for example, a general-purpose microprocessor (e.g., a CPU), an instruction set processor, and / or an associated chipset and / or a special-purpose microprocessor (e.g., an application-specific integrated circuit (ASIC)). The processor may also include onboard memory for caching purposes. The processor may include a single processing unit or multiple processing units for performing different actions of the method flow according to embodiments of the present invention.

[0034] The RAM stores various programs and data required for the operation of the electronic device. The processor, ROM, and RAM are interconnected via a bus. The processor executes various operations of the method flow according to embodiments of the present invention by executing programs in the ROM and / or RAM. It should be noted that the programs may also be stored in one or more memories other than ROM and RAM. The processor may also execute various operations of the method flow according to embodiments of the present invention by executing programs stored in said one or more memories.

[0035] According to embodiments of the present invention, the electronic device may further include an input / output (I / O) interface, which is also connected to a bus. The electronic device may also include one or more of the following components connected to the input / output (I / O) interface: an input section including a keyboard, mouse, etc.; an output section including a cathode ray tube (CRT), liquid crystal display (LCD), etc., and a speaker, etc.; a storage section including a hard disk, etc.; and a communication section including a network interface card such as a LAN card, modem, etc. The communication section performs communication processing via a network such as the Internet. A drive is also connected to the input / output (I / O) interface as needed. Removable media, such as magnetic disks, optical disks, magneto-optical disks, semiconductor memories, etc., are installed on the drive as needed so that computer programs read from them can be installed into the storage section as needed.

[0036] The program can rely on tangible storage media such as optical storage devices or magnetic storage devices. In another embodiment, the computer program can also be transmitted and distributed in the form of signals over a network medium, and downloaded and installed via a communication component, and / or installed from a removable medium. The program code contained in the computer program can be transmitted using any suitable network medium, including but not limited to: wireless, wired, etc., or any suitable combination thereof.

[0037] In such an embodiment, the computer program can be downloaded and installed from a network via a communication component, and / or installed from a removable medium. When the computer program is executed by a processor, it performs the functions defined in the system of this embodiment of the invention. According to embodiments of the invention, the systems, devices, apparatuses, modules, units, etc., described above can be implemented by computer program modules.

[0038] According to embodiments of the present invention, program code for executing the computer programs provided in the embodiments of the present invention can be written in any combination of one or more programming languages. Specifically, these computational programs can be implemented using high-level procedural and / or object-oriented programming languages, and / or assembly / machine languages. Programming languages ​​include, but are not limited to, languages ​​such as Java, C++, Python, "C", or similar programming languages. The program code can be executed entirely on the user's computing device, partially on the user's device, partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0039] Example 5 Thirdly, this embodiment provides a medium, a computer-readable storage medium that stores computer instructions, which cause a computer to execute the method described in embodiment 2 above.

[0040] The computer-readable storage medium may be included in the device / apparatus / system described in the above embodiments; or it may exist independently and not assembled into the device / apparatus / system. The computer-readable storage medium carries one or more programs that, when executed, implement the method according to the embodiments of the present invention.

[0041] According to embodiments of the present invention, a computer-readable storage medium may be a non-volatile computer-readable storage medium, such as including, but not limited to: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In the present invention, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. For example, according to embodiments of the present invention, a computer-readable storage medium may include ROM and / or RAM and / or one or more memories other than ROM and RAM as described above.

[0042] It is understood that the present invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Furthermore, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of the present invention.

Claims

1. A method for evaluating the symmetry of the branch potentials of the stator windings in a large integer slot generator, characterized in that: First, based on the number of stator slots... Z With extreme logarithm 2 p Calculate the slot spacing angle α Number of slots per pole per phase q ; Then based on the number of parallel branches N Establish branch wiring information data structure SW Each branch corresponds to one L A 6×6 matrix records the connection sequence and phase band attributes of the three-phase stator coils, and then based on the number of slots per pole and per phase. q Assigning data structure SW The phase band properties of each coil; further based on the slot pitch angle. α The three-phase potential of each branch is calculated based on the wiring information, and the virtual and real potentials are separated and stored in the potential data structure. BRE Next, rotate the potential of each branch of phase A as a whole. θ i Angle so that its end is perpendicular to the positive angle x When the axes coincide, the corresponding axes B and C rotate. θ i +240° and θ i After rotating by +120°, the results are stored separately. EA_R , EB_R and EC_R Based on this, the differences between all potential values ​​in each branch of phase A and phases B and C are calculated sequentially, and a similarity data structure is constructed. SIM ; and then judge SIM If a symmetric branch combination exists that meets the conditions, then its number is stored in the symmetric branch potential matrix. Sym Finally, if Sym The number of branches equals the total number of branches. N If the potential of the generator stator winding branch is good, it is determined that the potential is asymmetrical; otherwise, it is asymmetrical. Similarity data structure SIM The calculation expression is: ； Among them, elements MB n For phase B n The real and imaginary parts of the potential of each coil in the branch are related to the first phase of A. i The maximum difference in amplitude between the real and imaginary parts of the potential of each coil in the branch potential; element MC n For phase C n The real and imaginary parts of the potential of each coil in the branch are related to the first phase of A. i The maximum difference in amplitude between the real and imaginary parts of the potential of each coil in the branch potential; For the first rotation i The real and imaginary parts of the electromotive force of all coils in phase A of branch A, i.e., the rotating electromotive force data structure EA_R The Middle i A matrix; For the first rotation n The real and imaginary parts of the electromotive force of all coils in phase B of branch B, i.e., the rotating electromotive force data structure. EB_R The Middle n A matrix; For the first rotation n The real and imaginary parts of the electromotive force of all coils in phase C of a branch, i.e., the rotating electromotive force data structure. EC_R The Middle n A matrix; For phase B n Branch potential and phase A i The similarity of the branch potentials, i.e., the similarity data structure. SIM The Middle i The first row of the matrix n Column element values; For phase C n Branch potential and phase A i The similarity of branch potentials, i.e., similarity data structure. SIM The Middle i The second row of the matrix n Column element values.

2. The method for evaluating the symmetry of the branch potential of the stator winding of a large integer slot generator according to claim 1, characterized in that, Includes the following steps: Step S1: Utilize the number of generator stator slots Z With extreme logarithms 2p Calculate the slot spacing angle α Number of slots per pole per phase q ; Step S2: Based on the number of parallel branches of the stator winding N ,Establish N Branch wiring information data structure of the row SW ; Step S3: Set the data structure SW The Middle i ( i =1,2,…, N ) matrices SW { i }for L A 6-row, 6-column numerical matrix used to store the first... i The connection sequence of the three-phase stator coils of each branch and their phase band attributes; among which, L The total number of branch coils is represented by the matrix. Columns 1, 3, and 5 record the connection order of the three-phase stator coils A, B, and C from the neutral point side, respectively. Columns 2, 4, and 6 represent the phase band attributes of the corresponding coils, which are initially set to 0. Step S4, based on the matrix SW { i } and the number of slots per pole per phase q Each coil is assigned a corresponding phase band attribute. Step S5, based on the matrix SW { i } and slot pitch angle α Calculate the first i The three-phase potential values ​​at the ends of each coil in the branch are stored in the potential data structure after separating the real and virtual values. BRE Matrix in BRE { i }; Step S6: Calculate the first phase of phase A sequentially. i The terminal potential of the branch BRE { i }( L ,1:2) Tongzheng x Angle between axes θ i And thus rotate all its potential values ​​clockwise. θ i Angle, so that the end is perpendicular to the positive angle. x With axes aligned, the potential values ​​of each branch after rotation are stored in a rotating potential data structure. EA_R; Step S7, similarly, phases B and C are... i All potential values ​​of the branches rotate clockwise θ i +240° and θ i +120°, and store the rotated potential value in the data structure. EB_R and EC_R ; Step S8: Calculate the first phase of phase A sequentially. i The differences between the potential values ​​of all branches in phase B and phase C and the potential values ​​of all branches in phase C, and the difference in error capacity. err In this case, construct a similarity data structure SIM ; Step S9: Determine the similarity data structure SIM The Middle i matrices SIM { i If the sum of the elements in the two rows is greater than 1, then extract the column index of the first non-zero element in each row. N bi and N ci , the triple [ i , N bi , N ci Store the symmetric branch potential matrix Sym At the same time, all subsequent matrices SIM { i +1:end} is located in (1, N bi ) and (2, N ci The elements are cleared to zero; Step S10: Obtain the symmetric branch potential matrix Sym number of rows SNUM ,like SNUM = N If the branch potential of the generator stator winding is well symmetrical, then it is considered that the branch potential of the generator stator winding exhibits good symmetry; otherwise, it is asymmetrical.

3. The method for evaluating the symmetry of the branch potential of the stator winding of a large integer slot generator according to claim 2, characterized in that: In step S1, the slot pitch angle α and the number of slots per pole per phase q As shown in the following formula: ； 。 4. The method for evaluating the symmetry of the branch potential of the stator winding of a large integer slot generator according to claim 3, characterized in that: In step S4, the corresponding phase band attribute of each coil is described as follows: ； in, for Divide by The remainder, For the first i Branch number k Mutually( k =1 represents phase A. k =2 represents phase B. k =3 represents the C phase) in the first j The slot number of the root coil, i.e., the data structure SW The Middle i matrices SW { i } j line (2) k -1) Column element values; For the first i Branch number k The first j The phase band properties of the root coil, i.e., the data structure. SW The Middle i matrices SW { i } j OK 2k Column element values.

5. The method for evaluating the symmetry of the branch potential of the stator winding of a large integer slot generator according to claim 4, characterized in that: In step S5, the matrix BRE { i The expression for calculating} is: ； in, For the first i Branch number k The phase difference between the j-th coil in phase A and the first coil in phase A; For the first i The slot number of the first coil in phase A of branch A, i.e., the data structure. SW The Middle i matrices SW { i The value of the element in the first row and first column of}; For the first i Branch number k The first j The potential of +1 coil; For the first i Branch number k The first j The potential of the root coil; For the first i Branch number k The real part of the phase coil potential, i.e., the matrix BRE { i } second k -1 column contains all element values; For the first i Branch number k The imaginary part of the phase coil potential, i.e., the matrix BRE { i } second k List all element values; For the first i Branch number k The potential of all coils in a phase.

6. The method for evaluating the symmetry of the branch potential of the stator winding of a large integer slot generator according to claim 5, characterized in that: In step S6, the rotating potential data structure EA_R The calculation expression is: ； in, For the first i The imaginary part of the potential of the coil at the end of phase A of the branch, i.e., the matrix BRE { i }No. L The value of the element in the second column of the row; For the first i The real part of the coil potential at the end of phase A of the branch, i.e., the matrix BRE { i }No. L The value of the element in the first column of the row; For the first i Branch A, Phase A j The imaginary part of the potential of the root coil, i.e., the matrix BRE { i }No. j The value of the element in the second column of the row; For the first i Branch A, Phase A j The real part of the potential of the root coil, i.e., the matrix BRE { i }No. j The value of the element in the first column of the row; For the first rotation i Branch A phase number j The real part of the root coil potential, i.e., the rotating potential data structure. EA_R The Middle i The first matrix j The value of the element in row 1 and column 1; For the first rotation i Branch A phase number j The imaginary part of the root coil potential, i.e., the rotating potential data structure. EA_R The Middle i The first matrix j The value of the element in row 2 and column 2.

7. The method for evaluating the symmetry of the branch potential of the stator winding of a large integer slot generator according to claim 6, characterized in that: In step S7, the data structure EB_R and EC_R The calculation expression is: ； in, For the first i Branch B phase j The real part of the potential of the root coil, i.e., the matrix BRE { i }No. j The value of the element in the third column of the row; For the first i Branch B phase j The imaginary part of the potential of the root coil, i.e., the matrix BRE { i }No. j The value of the element in the 4th column of the row; For the first rotation i Branch B phase j The real part of the root coil potential, i.e., the rotating potential data structure. EB_R The Middle i The first matrix j The value of the element in row 1 and column 1; For the first rotation i Branch B phase j The imaginary part of the root coil potential, i.e., the rotating potential data structure. EB_R The Middle i The first matrix j The value of the element in row 2 and column 2; For the first i Branch C phase j The real part of the potential of the root coil, i.e., the matrix BRE { i }No. j The value of the element in the 5th column of the row; For the first i Branch C phase j The imaginary part of the potential of the root coil, i.e., the matrix BRE { i }No. j The value of the element in the 6th column of the row; For the first rotation i Branch C phase j The real part of the root coil potential, i.e., the rotating potential data structure. EC_R The Middle i The first matrix j The value of the element in row 1 and column 1; For the first rotation i Branch C phase j The imaginary part of the root coil potential, i.e., the rotating potential data structure. EC_R The Middle i The first matrix j The value of the element in row 2 and column 2.

8. A device, characterized in that: It includes a display device, a processor, a memory, and program instructions and operation modules stored in the memory and executable on the processor, wherein the processor executes the program instructions and operation modules to implement the method described in any one of claims 1-7.

9. A medium, characterized in that: A computer-readable storage medium stores computer instructions that cause a computer to perform the method described in any one of claims 1-7.

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