CN-122021149-A - Simulation analysis method and system for torque characteristic consistency of permanent magnet synchronous motor

CN122021149ACN 122021149 ACN122021149 ACN 122021149ACN-122021149-A

Abstract

The invention relates to a simulation analysis method and a simulation analysis system for torque characteristic consistency of a permanent magnet synchronous motor, and belongs to the technical field of consistency analysis of permanent magnet synchronous motors. The method comprises the steps of constructing a parameterized model capable of being independently assigned according to a motor structure, assigning an electromagnetic scheme, calculating electromagnetic loss through finite element analysis, constructing a magneto-thermal bidirectional coupling finite element simulation model, carrying out actual measurement statistics on repeated unit parameters such as the thickness of a batch of permanent magnets, identifying the optimal probability distribution type and distribution parameters of the parameters through fitting goodness-of-fit test and maximum likelihood estimation, utilizing Latin hypercube sampling and combining the identified optimal distribution to generate a plurality of groups of parameter data sets considering dispersibility, utilizing the magneto-thermal bidirectional coupling model to obtain torque characteristics, adopting a random forest model to construct a torque characteristic approximation model, utilizing the approximation model to calculate the torque characteristics, and utilizing the mean value and standard deviation of the torque characteristic approximation model to evaluate the torque characteristic consistency of the motor.

Inventors

WU LIQIN
YE XUERONG

Assignees

国网福建省电力有限公司电力科学研究院
国网福建省电力有限公司

Dates

Publication Date: 20260512
Application Date: 20260123

Claims (10)

1. The simulation analysis method for the torque characteristic consistency of the permanent magnet synchronous motor is characterized by comprising the following steps of: dividing structural parameters of the permanent magnet synchronous motor into non-repeating unit structural parameters and repeating unit structural parameters, extracting material characteristic parameters of the permanent magnet synchronous motor, and constructing a motor parameterized model on a simulation platform; the electromagnetic design scheme of the motor is assigned to a motor parameterized model, a motor electromagnetic model is established, and electromagnetic loss is calculated through finite element simulation; Carrying out actual measurement statistics on the repeated unit structure parameters and the material characteristic parameters of the batch motors, selecting a preset probability distribution candidate type for fitting goodness test, combining a maximum likelihood estimation method, taking the preset probability distribution candidate type with the maximum likelihood value as an optimal probability distribution type, and outputting the optimal probability distribution type and the corresponding distribution parameters; In the motor design domain, latin hypercube sampling is adopted to obtain a plurality of groups of motor design schemes, and each structure and material parameter is randomly sampled based on the optimal probability distribution type to form a data set; And calculating the torque characteristics of the batch motors by using the approximate model, and evaluating the consistency of the torque characteristics based on the mean value and the standard deviation of the torque characteristics.
2. The simulation analysis method for torque characteristic consistency of a permanent magnet synchronous motor according to claim 1, wherein the simulation platform is AnsysWorkbench, and the simulation platform constructs a motor parameterized model, specifically: Determining a point as the geometric center of the permanent magnet synchronous motor to be modeled, and defining the section contour locating point coordinates of a stator slot, a stator tooth and a permanent magnet of the permanent magnet synchronous motor through independent numbers in a polar coordinate system; The method comprises the steps of connecting and closing the coordinates of positioning points of the cross section profile of a stator slot sequentially through spline curves or straight line segments to generate a cross section profile area of a single stator slot, constructing a stator core annular structure with the outer diameter of the stator and the inner diameter of the stator, subtracting the cross section profile area of the single stator slot from the stator core annular structure, and obtaining an actual stator punching structure; The method comprises the steps of calculating according to the size chain of the outer radius and the inner radius of a permanent magnet, determining the boundary of an inner arc and an outer arc of the permanent magnet, combining the span angle of a polar arc, and constructing a section profile model of the permanent magnet; And further assigning structural parameters of the permanent magnet synchronous motor design to variables of the geometric model to form a motor parameterized model with independently assignable repeating units.
3. The method for simulation analysis of torque characteristic consistency of a permanent magnet synchronous motor according to claim 1, wherein the electromagnetic loss includes copper loss, iron loss and eddy current loss, and wherein: Copper loss is calculated based on the effective value of current, and expressed as: ; In the formula, The copper loss of the electromagnetic model of the permanent magnet synchronous motor is represented, Represents the phase number index of the permanent magnet synchronous motor, The total phase number of the permanent magnet synchronous motor is represented, Representing permanent magnet synchronous motor The effective value of the current in the phase windings, Representing permanent magnet synchronous motor Equivalent phase resistance of the phase windings; Based on the magnetic field density amplitude, the running frequency of the permanent magnet synchronous motor and a preset loss coefficient, the iron loss is calculated, and the iron loss is expressed as follows: ; ; ; ; In the formula, The iron loss of the electromagnetic model of the permanent magnet synchronous motor is represented, Indicating the hysteresis loss of the magnetic field, Indicating the loss of eddy currents, Indicating that the additional loss is to be taken, Indicating the frequency of the change in the magnetic flux density, Representing the maximum flux density in the core of the permanent magnet synchronous motor, Indicating the hysteresis loss factor(s), Indicating the coefficient of eddy-current loss, Representing the additional loss factor; based on the eddy current density, the eddy current loss is calculated by combining the conductivity and the volume of the permanent magnet, and expressed as the following formula: ; In the formula, Represents the eddy current loss of the electromagnetic model of the permanent magnet synchronous motor, Indicating the density of the eddy currents, Representing the density of the permanent magnet, Indicating the electrical conductivity of the permanent magnet material.
4. The simulation analysis method for torque characteristic consistency of a permanent magnet synchronous motor according to claim 1, wherein the method is characterized by constructing a magneto-caloric bidirectional coupling finite element simulation model, and specifically comprises the following steps: The method comprises the steps of taking electromagnetic loss of a motor electromagnetic model as a heat source, inputting the electromagnetic loss to a steady-state thermal coupling module of a simulation integration platform AnsysWorkbench, connecting the steady-state thermal coupling module with the motor electromagnetic model, setting a material temperature coefficient and temperature feedback in the steady-state thermal coupling module, and constructing a magneto-thermal bidirectional coupling finite element simulation model.
5. The simulation analysis method for torque characteristic consistency of a permanent magnet synchronous motor according to claim 1, wherein the method is characterized in that an optimal parameter distribution type and a corresponding distribution parameter are determined by using a fitting goodness test and maximum likelihood estimation method, and specifically comprises the following steps: Sampling repeated units in batch permanent magnet synchronous motor prototypes, and respectively measuring structural parameters and material characteristic parameters of the prototype repeated units by adopting an industrial CT and a fluxgraph to form repeated unit parameter sample data; Selecting a preset probability distribution candidate type based on repeating unit parameter sample data, wherein the preset probability distribution candidate type at least comprises normal distribution, exponential distribution, lognormal distribution and Weibull distribution, and calculating the number of sample grouping groups according to a Sturges formula, and the formula is as follows: ; In the formula, The number of groups of packets is indicated, Representing sample capacity; equidistant division is carried out on the value interval of the thickness of the permanent magnet according to the calculated sample grouping number, and the observation frequency in each grouping interval is counted; Calculating expected frequency corresponding to each grouping interval according to a theoretical probability density function of each preset probability distribution candidate type, calculating chi-square statistics based on the observed frequency and the expected frequency, and carrying out chi-square fitting goodness assumption test; based on the acceptable distribution types, respectively calculating the maximum log likelihood value of each distribution by using a maximum likelihood estimation method, taking the preset probability distribution candidate type with the maximum log likelihood value as the optimal probability distribution type of the repeated unit parameters, taking the parameter which enables the log likelihood function to reach the maximum value as the corresponding distribution parameter, and outputting the optimal probability distribution type and the corresponding distribution parameter.
6. The simulation analysis method for torque characteristic consistency of a permanent magnet synchronous motor according to claim 1, wherein the method inputs a data set into a motor electromagnetic model and outputs corresponding torque characteristics, specifically: inputting the data set into an electromagnetic model of the motor, and calculating to obtain electromagnetic loss; The magneto-thermal bidirectional coupling finite element simulation model feeds back the temperature rise of the permanent magnet synchronous motor in the running process to the motor body, corrects the internal material characteristics of the permanent magnet synchronous motor, and after the temperature is stabilized by cyclic iteration, the torque and torque fluctuation of the permanent magnet synchronous motor after the stable running are obtained, and the torque characteristics of the motor are analyzed and extracted to obtain the cogging torque and torque waveform of the permanent magnet synchronous motor under the rated working condition; Wherein, the temperature stabilization means that the difference between the temperature calculated at this time and the temperature at the last iteration does not exceed a set threshold.
7. The simulation analysis method for torque characteristic consistency of a permanent magnet synchronous motor according to claim 1, wherein the method is used for evaluating the consistency of the torque characteristic, and specifically comprises the following steps: Based on an approximate model, predicting torque characteristics of a plurality of permanent magnet synchronous motor samples under the same design scheme to obtain a torque characteristic data set of each sample motor under corresponding working conditions; Calculating a mean value of the torque characteristic for the torque characteristic data set, wherein the mean value is used for representing the integral output level of the batch permanent magnet synchronous motor under the working condition; the standard deviation of the torque characteristics is used as a torque consistency evaluation index, and when the standard deviation is smaller than a preset threshold value, the torque characteristics consistency of the batch of permanent magnet synchronous motors is judged to meet the design requirement; the smaller the standard deviation value is, the higher the consistency of the torque characteristics of the batch permanent magnet synchronous motors is.
8. The simulation analysis system for the torque characteristic consistency of the permanent magnet synchronous motor is characterized by comprising the following modules: The parameterized modeling module divides the structural parameters of the permanent magnet synchronous motor into non-repeated unit structural parameters and repeated unit structural parameters, extracts material characteristic parameters of the permanent magnet synchronous motor and constructs a motor parameterized model on the simulation platform; The magneto-thermal coupling simulation module is used for assigning the motor electromagnetic design scheme to a motor parameterized model, establishing a motor electromagnetic model and calculating electromagnetic loss through finite element simulation, inputting the electromagnetic loss as a heat source to the steady-state thermal coupling module of the simulation platform, and establishing a magneto-thermal bidirectional coupling finite element simulation model; The parameter distribution identification module is used for carrying out actual measurement statistics on the structural parameters and the material characteristic parameters of the repeated units of the batch motors, selecting a preset probability distribution candidate type for carrying out fitting goodness test, combining a maximum likelihood estimation method, taking the preset probability distribution candidate type with the maximum likelihood value as an optimal probability distribution type, and outputting the optimal probability distribution type and corresponding distribution parameters; The approximate model construction module is used for obtaining a plurality of groups of motor design schemes by Latin hypercube sampling in a motor design domain, randomly sampling each structure and material parameter based on the optimal probability distribution type to form a data set, inputting the data set into a motor electromagnetic model, and outputting corresponding torque characteristics; And the consistency evaluation module is used for calculating the torque characteristics of the batch motors by using the approximate model and evaluating the consistency of the torque characteristics based on the mean value and the standard deviation of the torque characteristics.
9. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor implements the method of any one of claims 1 to 7 when the program is executed by the processor.
10. A computer readable storage medium, on which a computer program is stored, characterized in that the program, when being executed by a processor, implements the method according to any one of claims 1 to 7.

Description

Simulation analysis method and system for torque characteristic consistency of permanent magnet synchronous motor Technical Field The invention relates to a simulation analysis method and a simulation analysis system for torque characteristic consistency of a permanent magnet synchronous motor, and belongs to the technical field of consistency analysis of permanent magnet synchronous motors. Background The permanent magnet synchronous motor has consistency problem due to the influence of processing dispersion, namely, the parameter dispersion is brought in the manufacturing process, so that the individual permanent magnet synchronous motors in batches have differences. The rotor system and the stator core structure are provided with repeating units, the dimension parameters and the material characteristics of the repeating units in a single motor are inconsistent due to processing uncertainty, and key influences are generated on the torque characteristics and consistency analysis results of the motor. The conventional symmetric finite element simulation model has limitations in evaluating torque characteristics of the permanent magnet synchronous motor. On the one hand, the traditional symmetrical finite element simulation model regards the motor repeating units as the identical structure, and the parameter difference between the single permanent magnet synchronous motor repeating units cannot be reflected, so that the permanent magnet synchronous motor simulation model which accords with the actual manufacturing process cannot be established. On the other hand, when the consistency simulation analysis is carried out on the permanent magnet synchronous motor, the motor parameters are sampled according to the distribution type of the structural parameters and the material characteristics of the permanent magnet synchronous motor, if the traditional symmetrical finite element simulation model is adopted for carrying out assignment and simulation on batch motor models, the obtained consistency simulation analysis result has larger difference from the actual, and the consistency distribution condition of the torque characteristics of the permanent magnet synchronous motor can not be accurately reflected. In the traditional analysis of torque fluctuation, the torque fluctuation of a single motor obtained by taking the model of the dispersibility of the repeating units into consideration is larger, so that the uncertainty of the torque fluctuation of the batch motors is increased, and the dispersibility of the torque fluctuation of the batch motors is underestimated by the symmetrical model. For torque consistency analysis, the standard deviation of the torque obtained by the ideal symmetric model is larger than that of the model considering the processing dispersion of the repeating units, because the torque is mainly influenced by the magnetizing quantity of the permanent magnet, the larger the magnetizing quantity of the repeating units of the permanent magnet is, the higher the torque is, and the influence by the dispersion degree of the magnetizing quantity of the repeating units is smaller. In the traditional symmetrical model, the magnetizing quantity of the permanent magnet repeating units in one motor is regarded as consistent, and when the magnetizing quantity is valued in the deviation range, the traditional symmetrical model can obtain samples with the repeating units being the consistent upper limit and the consistent lower limit of the magnetizing quantity, so that the torque of the sample model is large or small, and the standard deviation of the torque of the batch of simulation models is large. In the actual production process, the magnetizing quantity of the permanent magnet repeating units is inconsistent, so that the torque difference of the batch motors is not obvious as that of an ideal symmetrical model. The traditional symmetrical model overestimates the dispersity of the torque mean value of the batch motors, and the simulation model considering the machining dispersity of the repeated units can reflect the condition of inconsistent magnetizing quantity, so that the method is more suitable for practical conditions. Similar to torque fluctuation, for analysis of cogging torque consistency of a batch motor, a batch cogging torque mean value and a standard deviation obtained by model simulation considering machining dispersion of a repeating unit are larger than an ideal symmetrical model. Therefore, a method and a system for simulating and analyzing torque characteristic consistency of a permanent magnet synchronous motor are needed. Disclosure of Invention In order to solve the problems in the prior art, the invention provides a simulation analysis method and a simulation analysis system for torque characteristic consistency of a permanent magnet synchronous motor. The technical scheme of the invention is as follows: On one hand, the invention provides a simulation analysis method for torq