Motor controller test method and system, and storage medium

Abstract

The invention provides a motor controller test method and system, and a storage medium. The method comprises the following steps: selecting working points of a motor, and obtaining lookup table data of d-axis flux linkage, q-axis flux linkage, d-axis current, q-axis current and electrical angle at each working point from a lookup table pre-formed by a finite element lookup table model; carrying out fitting by utilizing lookup table data to obtain an analytical model of the d-axis flux linkage and the q-axis flux linkage; obtaining a voltage equation after the motor is optimized by using the analytical model, and obtaining an electromagnetic torque equation after the motor is optimized by using the analytical model; and the motor simulator tests a motor controller of the motor by using the optimized voltage equation and electromagnetic torque equation. According to the method, a motor analysis model based on flux linkage reconstruction and structural finite element fusion is constructed, simulation of magnetic saturation, a cross coupling effect and an air-gap magnetic field harmonic effect of the motor is realized on the basis of ensuring the real-time performance of the motor simulator, and the simulation precision of the motor simulator is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of motor hardware-in-the-loop testing, and in particular to a testing method for a motor controller, a system thereof, and a storage medium. Background Art

[0002] The Electric Motor Emulator (EME) is an emerging device for power-level testing of motor drive systems. Compared to traditional mechanical test benches, EMEs can simulate different types of motors through software model configuration, making the testing process more flexible and efficient. Furthermore, EMEs allow for safer testing of motors under extreme operating conditions and fault conditions, avoiding damage to the actual motor. This shortens the testing and development cycle and reduces R&D costs.

[0003] A motor simulator primarily consists of four components: a target motor model, a current control strategy, an interface coupling filter circuit, and a power inverter. The target motor model uses the inverter output voltage of the motor drive system under test as input, and the output target motor current also serves as the reference current for the motor simulator's interface coupling filter circuit, thereby simulating the electrical characteristics of the actual target motor. Therefore, the accuracy of the motor model solution fundamentally determines the precision of the motor simulator.

[0004] Most existing motor models used in motor simulators are linear mathematical models. While these models are computationally simple and fast, meeting the real-time requirements of motor simulators, they ignore the nonlinear characteristics of real motors (such as the motor's magnetic saturation effect, cross-coupling effect, and air gap magnetic field harmonics). Consequently, they exhibit poor accuracy and struggle to accurately describe the current characteristics of real motors under operating conditions. Target motor models based on finite element lookup table models, however, require magnetic flux data to be obtained from a pre-formed lookup table within the finite element lookup table model. While this approach can capture the motor's nonlinear characteristics (such as the motor's magnetic saturation effect, cross-coupling effect, and air gap magnetic field harmonics), better matching the operating characteristics of real motors and achieving the highest accuracy, the sheer volume of data required from the lookup table consumes significant FPGA (field programmable gate array) resources, placing high demands on FPGA performance and preventing real-time performance. Summary of the Invention

[0005] The main technical problem solved by the present invention is how to improve the simulation accuracy of the motor model while ensuring the real-time performance of the motor simulator. The present invention provides a test method for a motor controller, a system thereof, and a storage medium.

[0006] According to a first aspect, an embodiment provides a method for testing a motor controller, comprising:

[0007] Selecting an operating point of the motor and obtaining lookup table data of d-axis flux, q-axis flux, d-axis current, q-axis current, and electrical angle at each operating point from a lookup table pre-formed by a finite element lookup table model; wherein the finite element lookup table model is capable of characterizing the nonlinear characteristics of the motor, including magnetic saturation effect, cross-coupling effect, and air gap magnetic field harmonic effect;

[0008] deriving an analytical model of the d-axis magnetic flux and the q-axis magnetic flux by fitting the data in the lookup table;

[0009] Obtaining an optimized voltage equation of the motor using the analytical model, and / or obtaining an optimized electromagnetic torque equation of the motor using the analytical model;

[0010] The motor simulator tests the motor controller of the motor using the optimized voltage equation of the motor and the optimized electromagnetic torque equation of the motor.

[0011] In one embodiment, the fitting of the lookup table data to obtain the analytical model of the d-axis magnetic flux and the q-axis magnetic flux includes:

[0012] Performing Fourier series expansion on the d-axis magnetic flux and the q-axis magnetic flux respectively using the lookup table data to obtain the first N Fourier series of the d-axis magnetic flux and the q-axis magnetic flux;

[0013] Using the d-axis current and the q-axis current, a polynomial fit is performed on the Fourier coefficients of the first N Fourier series to obtain an approximate expression for the Fourier coefficients;

[0014] The analytical models of the d-axis magnetic flux and the q-axis magnetic flux are obtained using the approximate expression of the Fourier coefficient and the first N Fourier series. The expressions of the first N Fourier series of the d-axis magnetic flux and the q-axis magnetic flux are respectively:

[0015]

[0016] in,

[0017]

[0018] θ e Indicates the electrical angle of the motor, They represent the Fourier coefficients of the nth cosine component and sine component of the Fourier series of the d-axis magnetic flux at the mth operating point, and They represent the Fourier coefficients of the nth cosine component and sine component of the Fourier series of the q-axis magnetic flux at the mth operating point, respectively, and T represents θ e cycle.

[0019] In one embodiment, the approximate expression of the Fourier coefficient is:

[0020]

[0021] Among them, a n_d and b n_d They represent the Fourier coefficients of the nth cosine component and sine component of the Fourier series of the d-axis magnetic flux obtained by polynomial fitting, respectively. Here, a n_q and b n_q They represent the Fourier coefficients of the nth cosine component and sine component of the Fourier series of the q-axis magnetic flux obtained by polynomial fitting, and Respectively represent a n_d 、a n_q 、b n_d and b n_q The coefficient array of the fitting polynomial, X(i d ,i q ) represents the d-axis current i d and q-axis current i q The polynomial basis formed;

[0022]

[0023] M represents the highest order of the polynomial basis. The larger the value of M, the smaller the difference between the analytical model of the d-axis flux and the q-axis flux and the lookup table data of the d-axis flux and the q-axis flux respectively.

[0024] and Represents the coefficient arrays respectively The coefficients of Represents the coefficient arrays respectively The coefficients of Represents the coefficient arrays respectively The coefficients of Represents the coefficient arrays respectively The coefficients of .

[0025] In one embodiment, the analytical models of the d-axis magnetic flux and the q-axis magnetic flux are expressed as follows:

[0026]

[0027] Among them, C(θ e ), S(θ e ), A d 、A q 、B d and B q The expressions are:

[0028]

[0029] In one embodiment, the step of obtaining the optimized voltage equation of the motor using the analytical model and / or the step of obtaining the optimized electromagnetic torque equation of the motor using the analytical model includes:

[0030] Based on harmonic analysis, the order reduction processing is performed on the analytical models of the d-axis magnetic flux and the q-axis magnetic flux to obtain the analytical models of the d-axis magnetic flux and the q-axis magnetic flux after the order reduction processing respectively;

[0031] The optimized voltage equation of the motor is obtained by using the analytical model of the d-axis flux and the q-axis flux after the order reduction processing, and / or the electromagnetic torque equation of the motor is obtained by using the analytical model of the d-axis flux and the q-axis flux after the order reduction processing; wherein C(θ e ), S(θ e ), A d 、A q 、B d and B q The expressions are:

[0032]

[0033] And N0=N / 6.

[0034] In one embodiment, the method of obtaining the optimized voltage equation of the motor using the analytical model of the d-axis flux and the q-axis flux after the order reduction process includes:

[0035] Substituting the analytical models of the d-axis flux and the q-axis flux after the order reduction process into the first expression of the voltage equation, the second expression of the voltage equation is obtained; wherein the first expression of the voltage equation is:

[0036]

[0037] u d and u q They represent the d-axis component and q-axis component of the output voltage of the drive unit in the motor, R s Represents the phase resistance of the motor, ω e Indicates the electrical angular velocity of the motor;

[0038] Performing full differentiation on the analytical models of the d-axis flux linkage and the q-axis flux linkage after the order reduction process to obtain analytical models of the d-axis flux linkage and the q-axis flux linkage after the full differentiation process;

[0039] Substituting the analytical model of the d-axis flux and the q-axis flux after full differentiation into the second expression of the voltage equation, the voltage equation of the motor after optimization is obtained; wherein, the expression of the voltage equation of the motor after optimization is:

[0040] in, dX d and dX q Respectively represent X(i d ,i q )About i d and i q The differential of C′(θ e )S′(θ e ) respectively represent the C(θ e ) and S(θ e ) in θ e Find the derivative.

[0041] In one embodiment, the method of obtaining the electromagnetic torque equation of the motor using the analytical model of the d-axis flux and the q-axis flux after the order reduction process includes:

[0042] The first expression of the electromagnetic torque equation is obtained by using the expression of magnetic co-energy and the relationship between electromagnetic torque and magnetic co-energy; wherein, the expression of magnetic co-energy is:

[0043]

[0044] in, i′ d Refers to the i d , i′ q Refers to the i q ; The first expression of the electromagnetic torque equation is:

[0045]

[0046] P n Indicates the number of pole pairs of the motor;

[0047] The optimized electromagnetic torque equation of the motor is obtained by using the expression of the cogging torque of the motor and the first expression of the electromagnetic torque equation; wherein the expression of the cogging torque is obtained by pre-fitting, and the expression of the cogging torque is: T cog (θ e )=a1sin(b1x+c1); a1, b1 and c1 are the fitting coefficients of the cogging torque, and x represents the electrical angle; the electromagnetic torque equation of the motor after optimization is: T e =T e1 +T cog .

[0048] According to a second aspect, an embodiment provides a test system for a motor controller, comprising:

[0049] a preprocessing module configured to precalculate and store results of a finite element analysis of the motor using a finite element lookup table model to form a lookup table; wherein the finite element lookup table model is capable of characterizing nonlinear characteristics of the motor, including magnetic saturation, cross-coupling effects, and air gap magnetic field harmonic effects;

[0050] a flux reconstruction module configured to select an operating point of the motor and obtain, from the lookup table, the d-axis flux, the q-axis flux, the d-axis current, the q-axis current, and the electrical angle at each operating point;

[0051] an analytical model building module configured to obtain an analytical model of the d-axis magnetic flux and the q-axis magnetic flux by fitting the data in the lookup table;

[0052] a motor model building module, configured to obtain an optimized voltage equation of the motor using the analytical model, and / or to obtain an optimized electromagnetic torque equation of the motor using the analytical model;

[0053] The motor simulator is configured to test the motor controller of the motor by using the optimized voltage equation of the motor and the optimized electromagnetic torque equation of the motor.

[0054] In one embodiment, the step of obtaining the optimized voltage equation of the motor using the analytical model and / or the step of obtaining the optimized electromagnetic torque equation of the motor using the analytical model includes:

[0055] Based on harmonic analysis, the order reduction processing is performed on the analytical models of the d-axis magnetic flux and the q-axis magnetic flux to obtain the analytical models of the d-axis magnetic flux and the q-axis magnetic flux after the order reduction processing respectively;

[0056] The optimized voltage equation of the motor is obtained by using the analytical models of the d-axis flux and the q-axis flux after the order reduction processing, and / or the optimized electromagnetic torque equation of the motor is obtained by using the analytical models of the d-axis flux and the q-axis flux after the order reduction processing.

[0057] According to a third aspect, an embodiment provides a computer-readable storage medium, wherein the computer-readable storage medium includes a program, wherein the program can be executed by a processor to implement the method described in any embodiment herein.

[0058] The beneficial effects of this application are:

[0059] The test method of the motor controller of the present application reconstructs the flux, that is, the above-mentioned "using the lookup table data for fitting to obtain the analytical model of the d-axis flux and the q-axis flux", which changes the process of searching for the required flux data in the lookup table into a process of obtaining the required data through the analytical model, thereby reducing resource usage and improving the real-time performance of the calculation while retaining the nonlinear characteristics of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 A flowchart of a method for testing a motor controller according to an embodiment of the present invention is provided;

[0061] Figure 2 A schematic diagram of a process for obtaining an analytical model of d-axis flux and q-axis flux by fitting with lookup table data according to an embodiment;

[0062] Figure 3 A schematic diagram of a flow chart of obtaining an optimized voltage equation and / or electromagnetic torque equation for a motor according to an embodiment;

[0063] Figure 4 A schematic diagram of a flow chart of obtaining a voltage equation after motor optimization according to an embodiment;

[0064] Figure 5 A schematic diagram of a flow chart for obtaining an optimized electromagnetic torque equation of a motor according to an embodiment;

[0065] Figure 6 A schematic diagram of a logical calculation framework of an optimized voltage equation and electromagnetic torque equation obtained by the method according to an embodiment;

[0066] Figure 7 Schematic diagram of comparative data results of d-axis flux after order reduction processing in one embodiment;

[0067] Figure 8 Schematic diagram of comparative data results of q-axis flux after order reduction processing in one embodiment;

[0068] Figure 9 The electromagnetic torque and I under no-load condition of an embodiment are s Schematic diagram of the comparison results of electromagnetic torque when =1A, β=80°;

[0069] Figure 10 A module diagram of a motor controller test system according to an embodiment. DETAILED DESCRIPTION

[0070] The present invention will be further described in detail below by means of specific embodiments in conjunction with the accompanying drawings. Similar elements in different embodiments are numbered with associated similar elements. In the following embodiments, many detailed descriptions are provided to enable the present application to be better understood. However, those skilled in the art will readily appreciate that some of the features may be omitted in different circumstances, or may be replaced by other elements, materials, or methods. In some cases, some operations related to the present application are not shown or described in the specification. This is to avoid the core portion of the present application being overwhelmed by excessive descriptions, and for those skilled in the art, it is not necessary to describe these related operations in detail. They will fully understand the related operations based on the description in the specification and the general technical knowledge in the art.

[0071] In addition, the features, operations, or characteristics described in the specification may be combined in any appropriate manner to form various embodiments. Furthermore, the steps or actions in the method description may be reordered or adjusted in a manner readily apparent to those skilled in the art. Therefore, the various sequences in the specification and drawings are provided solely for the purpose of clearly describing a particular embodiment and are not intended to be mandatory, unless otherwise specified.

[0072] The serial numbers assigned to components herein, such as "first," "second," etc., are used solely to distinguish the objects being described and do not convey any sequential or technical meaning. References to "connection" and "coupling" herein, unless otherwise specified, include both direct and indirect connections (couplings).

[0073] Existing conventional motor models based on finite element lookup table models require a large amount of resources and storage space due to the large amount of data. Reducing the data amount can reduce resource usage but will result in poor accuracy of the motor model.

[0074] The technical solution of the present application will be described in detail below with reference to embodiments.

[0075] Please refer to Figure 1 The present application provides a method for testing a motor controller. The method comprises:

[0076] Step S100: Select a working point and obtain the required lookup table data;

[0077] Step S200: fitting an analytical model using the lookup table data;

[0078] Step S300: obtaining an optimized voltage equation of the motor using an analytical model, and / or obtaining an optimized electromagnetic torque equation of the motor using an analytical model;

[0079] Step S400: The motor simulator tests the motor controller of the motor using the optimized voltage equation and the optimized electromagnetic torque equation of the motor.

[0080] Specifically, in step S100, the operating point of the motor is selected, and the lookup table data of the d-axis flux, q-axis flux, d-axis current, q-axis current and electrical angle at each operating point are obtained from the lookup table pre-formed by the finite element lookup table model; wherein, the finite element lookup table model can characterize the nonlinear characteristics of the motor, and the above-mentioned nonlinear characteristics include magnetic saturation effect, cross-coupling effect and air gap magnetic field harmonic effect.

[0081] In some embodiments, in step S100, the operation of the motor can be considered to consist of multiple steady-state current operating points. The operating points of the motor can be expressed in polar coordinates in the synchronous coordinate system as (I s m ,β m ), where I s is the stator current space vector amplitude, β is the torque angle, and m represents the mth operating point. For example, the operating point of the motor can be selected in the following way: the actual operating range of the motor for the stator current space vector amplitude Is and the torque angle β is divided into w I With w β According to the power equivalence principle, W motor current operating points in the synchronous coordinate system are obtained, W = w I ×w β Those skilled in the art may also use other existing methods to select the operating point of the motor.

[0082] In some embodiments, in step S100, when each operating point of the motor has been determined, the current corresponding to each operating point can be used as the current excitation in the finite element simulation model to obtain the flux data of the motor at the corresponding operating point. For example, the lookup table data of the d-axis flux and the q-axis flux obtained at this time can be expressed as Since the d-axis current i d , q-axis current i q and the stator current space vector amplitude I s and the torque angle β satisfy the following relationship: d =I s cosβ,i q =I s sinβ, therefore, the lookup table data of the d-axis flux and the q-axis flux can be expressed as: The θ in the e .f d Indicates the finite element lookup table model and The mapping relationship, f q Indicates the finite element lookup table model and The mapping relationship.

[0083] It should be noted that in step S100, the above-mentioned specific process of "using the current corresponding to each working point as the current excitation in the finite element simulation model to obtain the magnetic flux data at the corresponding working point of the motor" is a conventional technical means in this field. The finite element lookup table model is a model that combines finite element analysis and lookup table technology, and is mainly used to improve calculation efficiency and accuracy. The finite element lookup table model pre-calculates and stores the results of the finite element analysis to form a lookup table, and then directly looks up the results from the table when needed, thereby reducing the real-time calculation amount and improving the simulation speed. Since the specific process of "obtaining the lookup table data of the d-axis magnetic flux, q-axis magnetic flux, d-axis current, q-axis current and electrical angle at each working point from the lookup table pre-formed by the finite element lookup table model" is a conventional technical means in this field, it will not be repeated here.

[0084] It can be understood that in step S100, the above lookup table can reflect the corresponding relationship between the magnetic flux and the three variables of d-axis current, q-axis current and electrical angle.

[0085] For some examples, please refer to Figure 2 In step S200, the analytical model of the d-axis magnetic flux and the q-axis magnetic flux is obtained by fitting the data in the lookup table, including:

[0086] Step S210: performing Fourier series expansion on the d-axis flux and the q-axis flux respectively using the lookup table data to obtain the first N Fourier series of the d-axis flux and the q-axis flux;

[0087] Step S220: performing polynomial fitting on the Fourier coefficients of the first N Fourier series using the d-axis current and the q-axis current to obtain an approximate expression for the Fourier coefficients;

[0088] Step S230: deriving analytical models of the d-axis magnetic flux and the q-axis magnetic flux using the approximate expression of the Fourier coefficient and the first N terms of the Fourier series.

[0089] It can be understood that the above step S200 is a process of flux reconstruction, which fits the lookup table data that cannot be described by an analytical model (such as the lookup table data of d-axis flux, q-axis flux, d-axis current, q-axis current and electrical angle) into an analytical equation. That is, the process of searching for the required flux data in the lookup table is changed to a process of obtaining the required data through an analytical model, which reduces resource usage and ensures the real-time performance of the motor simulator.

[0090] It is understood that in step S210, N is the number of terms in the Fourier series expansion. The larger the value of N, the higher the harmonic order that can be reflected by the analytical model finally obtained in step S230.

[0091] In some embodiments, in step S210, due to the fixed working point Under the condition of θ, the d-axis magnetic flux and the q-axis magnetic flux change with the electrical angle θ. e It shows periodic changes. Therefore, the expressions of the first N Fourier series of the d-axis magnetic flux and the q-axis magnetic flux are:

[0092]

[0093] in,

[0094]

[0095] θ e Indicates the electrical angle of the motor, They represent the Fourier coefficients of the nth cosine component and sine component of the Fourier series of the d-axis magnetic flux at the mth operating point, and They represent the Fourier coefficients of the nth cosine component and sine component of the Fourier series of the q-axis magnetic flux at the mth operating point, respectively, and T represents the electrical angle θ e The period is T = 2π.

[0096] In some embodiments, in step S220, since the above-mentioned Fourier coefficient is the current (i d ,i q ), using the lookup table data of d-axis flux, q-axis flux, d-axis current, q-axis current and electrical angle at each working point obtained in step S100, and based on i d and i q The M-order symmetric polynomial is fitted to the Fourier coefficients at all operating point currents, and then the approximate expression of the Fourier coefficients can be obtained. n_d 、a n_q 、b n_d and b n_q For example, the above Fourier coefficients can be obtained by using a bivariate polynomial fitting with respect to the operating point current (i d ,i q ) is approximate as:

[0097]

[0098] Among them, a n_d and b n_d They represent the Fourier coefficients of the nth cosine component and sine component of the Fourier series of the d-axis magnetic flux obtained by polynomial fitting, where a n_q and b n_qThey represent the Fourier coefficients of the nth cosine component and sine component of the Fourier series of the q-axis magnetic flux obtained by polynomial fitting, and Respectively represent a n_d 、a n_q 、b n_d and b n_q The coefficient array of the fitting polynomial, X(i d ,i q ) represents the d-axis current i d and q-axis current i q The polynomial basis formed;

[0099]

[0100] M represents the highest order of the polynomial basis; if the value of M is larger, the gap between the analytical model of the d-axis magnetic flux and the q-axis magnetic flux and the lookup table data of the d-axis magnetic flux and the q-axis magnetic flux will be smaller. Represents the coefficient arrays respectively The coefficients of Represents the coefficient arrays respectively The coefficients of Represents the coefficient arrays respectively The coefficients of Represents the coefficient arrays respectively The coefficients of the coefficient array are all fitted based on the lookup table data. The polynomial basis refers to a basis composed of a set of unit polynomials. Those skilled in the art can determine the specific value of M based on the actual application scenario.

[0101] In some embodiments, in step S200, the expressions of the analytical models of the d-axis magnetic flux and the q-axis magnetic flux are respectively:

[0102]

[0103] Among them, the coefficient matrix of the analytical model C(θ e ), S(θ e ), A d 、A q 、B d and B q The expressions are:

[0104]

[0105] In some embodiments, after obtaining the analytical models of the d-axis flux and the q-axis flux in step S200, the desired voltage equation and / or electromagnetic torque equation can be obtained directly using step S320 (i.e., without the order reduction processing of step S310). The specific process of "directly obtaining the desired voltage equation and / or electromagnetic torque equation using step S320 (i.e., without the order reduction processing of step S310)" can be referred to in steps S310 to S320 and will not be further described here.

[0106] For some examples, please refer to Figure 3 In step S300, the voltage equation of the motor after optimization is obtained by using the analytical model, and / or the electromagnetic torque equation of the motor after optimization is obtained by using the analytical model, including:

[0107] Step S310: performing order reduction processing on the analytical models of the d-axis flux and the q-axis flux based on harmonic analysis to obtain the analytical models of the d-axis flux and the q-axis flux after order reduction processing respectively;

[0108] Step S320: using the analytical models of the d-axis flux and the q-axis flux after the order reduction process to obtain the optimized voltage equation of the motor, and / or using the analytical model to obtain the optimized electromagnetic torque equation of the motor.

[0109] In some embodiments, in step S310, under an ideal three-phase symmetrical sinusoidal current input, the d-axis flux and the q-axis flux contain only the 6kth harmonic flux that varies with the torque angle, in addition to the DC component. Therefore, other harmonics can be ignored and the coefficient matrix of the analytical model can be reduced to obtain the analytical models of the d-axis flux and the q-axis flux after the reduced-order processing, thereby reducing the computational complexity. In step S310, the expressions of the analytical models of the d-axis flux and the q-axis flux after the reduced-order processing are respectively:

[0110]

[0111] After the order reduction, the coefficient matrix of the analytical model of the d-axis magnetic flux and the q-axis magnetic flux is C(θ e ), S(θ e ), A d 、A q 、B d and B q The expressions are:

[0112]

[0113] And N0=N / 6.

[0114] In some embodiments, the analytical model of the d-axis flux and the q-axis flux obtained after the order reduction process in step S310 can be combined to derive the d-axis voltage u d , q-axis voltage u q is the input, d-axis current i d , q-axis current i q is the output voltage equation. Please refer to Figure 4 In step S320, the optimized voltage equation of the motor is obtained by using the analytical model of the d-axis flux and the q-axis flux after the order reduction process, including:

[0115] Step S321a: Substitute the analytical models of the d-axis flux and the q-axis flux after the order reduction process into the first expression of the voltage equation to obtain the second expression of the voltage equation; the first expression of the voltage equation is the voltage equation of the permanent magnet synchronous motor in the dq coordinate system. The voltage equation of the permanent magnet synchronous motor in the dq coordinate system can be expressed as:

[0116]

[0117] u d and u q They represent the d-axis component and q-axis component of the output voltage of the drive unit in the motor, R s Represents the phase resistance of the motor (such as a permanent magnet synchronous motor), ω e Represents the electrical angular velocity of the motor, i d and i q denote the d-axis current and q-axis current, ψ d and ψ q represent the d-axis flux and the q-axis flux, respectively (such as the analytical models of the d-axis flux and the q-axis flux obtained in step S200 ); the second expression of the voltage equation is:

[0118]

[0119] and represent the analytical models of the d-axis magnetic flux and the q-axis magnetic flux after the reduced-order processing, respectively.

[0120] Step S322a: Fully differentiate the analytical models of the d-axis flux and the q-axis flux after the order reduction process to obtain analytical models of the d-axis flux and the q-axis flux after full differentiation; wherein the expressions of the analytical models of the d-axis flux and the q-axis flux after full differentiation are respectively:

[0121]

[0122] Step S323a: Substituting the analytical model of the d-axis flux and the q-axis flux after the full differentiation into the second expression of the voltage equation to obtain the optimized voltage equation of the motor;

[0123] Among them, the expression of the voltage equation of the motor after optimization is:

[0124] in, dX d and dX q Respectively represent X(i d ,i q )About i d and i q The differential of C′(θ e )S′(θ e ) respectively represent the C(θ e ) and S(θ e ) in θ e Find the derivative.

[0125] In some embodiments, in practical applications, these two differential equations (such as ) performs forward Euler discretization and computes iterations for application in motor simulators or other fields.

[0126] In some embodiments, the first expression of the voltage equation in step S321a may also be the voltage equation of other types of motors in the dq coordinate system. The voltage equations of different motor types may be different, that is, the first expression of the voltage equation in step S321a may also be in other forms.

[0127] In some embodiments, the above two differential equations (such as ) is integrated, and then u d and u q is the input (which is contained in the c and f items), with i d and i q It is understood that the optimized voltage equation can be directly applied to the motor simulator.

[0128] In some embodiments, by combining the analytical models of the d-axis flux and the q-axis flux after the order reduction process in step S310 and taking the cogging torque into consideration, a high-precision electromagnetic torque equation can be obtained. Figure 5 In step S320, the optimized electromagnetic torque equation of the motor is obtained by using the analytical model of the d-axis flux and the q-axis flux after the order reduction process, including:

[0129] Step S321b: Obtain a first expression of the electromagnetic torque equation using the expression of magnetic co-energy and the relationship between electromagnetic torque and magnetic co-energy; wherein the expression of magnetic co-energy is:

[0130]

[0131] in,

[0132]

[0133] i d ' refers to the i d ,i q ' refers to the i q ; The first expression of the electromagnetic torque equation is:

[0134] P n Indicates the number of pole pairs of the motor;

[0135] Step S322b: Utilize the expression of the cogging torque of the motor and the first expression of the electromagnetic torque equation to obtain the optimized electromagnetic torque equation of the motor; wherein the expression of the cogging torque is pre-fitted using finite element simulation data under no-load conditions, and the expression of the cogging torque is: T cog (θ e )=a1sin(b1x+c1); a1, b1 and c1 are all fitting coefficients of the cogging torque, and x represents the electrical angle.

[0136] It should be noted that, since the process of pre-fitting the cogging torque using finite element simulation data under no-load conditions is a conventional technical means in this field, it will not be described in detail here.

[0137] It should be noted that for those skilled in the art, the expression of magnetic co-energy and the relationship between electromagnetic torque and magnetic co-energy in step S321b is unique and unambiguous. Therefore, it will not be described in detail here. cog (θ e )=a1sin(b1x+c1) describes the relationship between the cogging torque and the electrical angle.

[0138] After that, the high-precision electromagnetic torque equation considering the cogging torque can be obtained as: T e =T e1 +T cog Furthermore, the mechanical motion equation of the motor can be expressed as:

[0139]

[0140] Among them, ω m represents the mechanical angular velocity of the motor; J represents the moment of inertia of the system (including the rotor); B represents the damping coefficient, which is usually a nonlinear function of the angular velocity; T e Represents electromagnetic torque; T LRepresents load torque, including no-load torque (no-load torque is caused by the motor's no-load losses and can be considered a constant resistance torque). The mechanical equation of motion describes the motion of the motor under the influence of electromagnetic torque and load torque. By controlling the electromagnetic torque, the motor speed and rotation can be precisely controlled.

[0141] It should be noted that the motor simulator uses the motor's optimized voltage equation and the motor's optimized electromagnetic torque equation to simulate the motor and calculate the current and speed characteristics under given voltage and load conditions. The motor simulator is used to simulate the motor to test the motor controller. Since the specific process of "the motor simulator uses the motor's optimized voltage equation and the motor's optimized electromagnetic torque equation to test the motor controller of the motor" in step S400 is prior art in this field, the specific process will not be repeated here.

[0142] Please refer to Figure 6 , Figure 6 The figure shows the logic calculation framework of the voltage equation and the electromagnetic torque equation obtained by the method after optimization in some embodiments; wherein, add represents the addition operation, and x in the solid rectangular box represents the multiplication symbol. Figure 6 The remaining symbols in are described above and will not be repeated here. The high-precision voltage equation and electromagnetic torque equation obtained by this method can be directly applied to the motor simulator.

[0143] Please refer to Figure 7 , Figure 7 Figures a and b show I s =1A, the comparison data results of the d-axis flux after reduced-order processing when the torque angle β is equal to 60 degrees and 80 degrees respectively. The horizontal and vertical axes in Figures a and b represent the electrical angle θ respectively. e (units are degrees (deg)) and flux Flux (units are Weber (Wb)). The "reconstructed flux" in Figures a and b represents the flux calculated using the analytical model of the reduced-order flux in step S300. The "finite element" in Figures a and b represents the flux lookup table data obtained using the finite element lookup table model in step S100. Comparing Figures a and b shows that the results of this method and the finite element method are essentially consistent. That is, the analytical model of this method (such as the analytical model of the reduced-order flux in step S300) has a better fitting effect, with a fitting error of 2‰ for the maximum flux at both torque angles.

[0144] Please refer to Figure 8 , Figure 8 Figures c and d show I s=1A, and the torque angle β is equal to 60 degrees and 80 degrees respectively. The horizontal and vertical axes in Figures c and d represent the electrical angle θ respectively. e and flux Flux (the unit of flux is Weber (Wb)). The "reconstructed flux" in Figures c and d represents the flux calculated by the analytical model after the reduced-order flux processing in step S300. The "finite element" in Figures c and d represents the flux lookup table data obtained by the finite element lookup table model in step S100. A comparison of Figures c and d shows that the error between the flux calculated by the analytical model after the reduced-order flux processing and the flux obtained by the finite element lookup table model does not exceed 3% (3% is within the acceptable range in this field).

[0145] Please refer to Figure 9 , Figure 9 Figures e and f show the electromagnetic torque (i.e., cogging torque) and I under no-load conditions, respectively. s =1A,β=80°, the horizontal and vertical axes in Figures e and f represent the electrical angle θ respectively. e and electromagnetic torque T e (T e The unit is Newton-meter (N·m). The "flux reconstruction" in Figures e and f represents the electromagnetic torque calculated using the electromagnetic torque equation of this method, and the "finite element" in Figures e and f represents the electromagnetic torque obtained using finite element analysis software. A comparison of Figures e and f shows that the curve representing the electromagnetic torque calculated by this method essentially coincides with the curve representing the electromagnetic torque obtained using finite element analysis software, indicating that the simulation accuracy of the electromagnetic torque calculated by this method is relatively accurate.

[0146] It can be seen that in some embodiments, the optimized voltage equation and the optimized electromagnetic torque equation obtained by the test method of the present application are particularly suitable for motor simulators. This is because the application on the motor simulator requires the motor model to run in a real single-chip microcomputer or FPGA (field programmable gate array), rather than running on a simulation software on a personal computer (PC) such as Simulink (a visual simulation tool), PSIM (a simulation application package software for the power electronics field and the motor control field), etc., so there are special requirements for real-time performance. It is specifically reflected in: 1) The essence of the analytical model of the motor is to solve differential equations, so when running the calculation in the FPGA, the calculation must be completed within the set time step, otherwise it will lead to inaccurate calculations; 2) The smaller the calculation step of the analytical model of the motor, the closer it is to continuity, so it can better simulate the motor in the real world. The test method of the motor controller of the present application can also be applied to other purposes besides motor simulators.

[0147] It can be seen that in some embodiments, the test method of the motor controller of the present application reconstructs the flux, that is, the above-mentioned step S200 "uses the lookup table data to fit and obtain the analytical model of the d-axis flux and the q-axis flux", which changes the process of searching for the required flux data in the lookup table into a process of obtaining the required data through the analytical model, thereby reducing resource usage and ensuring the real-time performance of the motor simulator. In other words, this method combines high-precision lookup table data to fit a motor analytical model that is easy to calculate, thereby reducing resource usage while retaining the nonlinear characteristics of the motor and improving the real-time performance of the calculation. Compared with linear mathematical models, this method can ensure real-time requirements while improving the accuracy of the motor model; compared with motor models based on finite element lookup table models, this method reduces resource usage, improves the real-time performance of the motor model while ensuring the accuracy requirements of the motor model.

[0148] It can be seen that in some embodiments, the test method of the motor controller of the present application reduces the order of the analytical model obtained by step S200 through step S310 based on harmonic analysis, that is, further simplifies the analytical model to further reduce the computational complexity of the motor model; then, in step S320, the voltage equation of the motor after optimization is obtained by using the analytical model of the d-axis flux and the q-axis flux after the order reduction, and / or the electromagnetic torque equation of the motor after optimization is obtained by using the analytical model of the d-axis flux and the q-axis flux after the order reduction. Compared with the linear mathematical model, this method can further ensure the real-time requirements while improving the accuracy of the motor model; compared with the motor model based on the finite element lookup table model, this method further reduces resource usage, and further ensures the accuracy requirements of the motor model while improving the real-time performance of the motor model. This method can achieve comprehensive optimization in terms of both the accuracy of the motor model and the real-time performance of the calculation.

[0149] It can be seen that in some embodiments, the testing method of the motor controller of the present application can simulate the magnetic saturation, cross-coupling effect and air gap magnetic field harmonic effect of the motor while ensuring the real-time performance of the motor simulator, thereby improving the simulation accuracy of the motor simulator.

[0150] The above is some description about a test method of a motor controller. In some embodiments of the present application, a test system for a motor controller is also disclosed. Figure 10 , the system comprises:

[0151] The pre-processing module 100 is configured to pre-calculate and store the results of the finite element analysis of the motor using a finite element lookup table model to form a lookup table;

[0152] The flux reconstruction module 200 is configured to select an operating point of the motor and obtain lookup table data for d-axis flux, q-axis flux, d-axis current, q-axis current, and electrical angle at each operating point from a lookup table pre-formed by a finite element lookup table model. The finite element lookup table model can characterize the nonlinear characteristics of the motor, including magnetic saturation, cross-coupling effects, and air gap magnetic field harmonic effects.

[0153] The analytical model building module 300 is configured to obtain the analytical model of the d-axis flux linkage and the q-axis flux linkage by fitting the data in the lookup table;

[0154] The motor model building module 400 is configured to obtain the optimized voltage equation of the motor using the analytical model, and / or obtain the optimized electromagnetic torque equation of the motor using the analytical model;

[0155] The motor simulator 500 is configured to test the motor controller of the motor using the optimized voltage equation and the optimized electromagnetic torque equation of the motor.

[0156] It should be noted that the lookup table generated by the preprocessing module includes lookup table data for d-axis flux, q-axis flux, d-axis current, q-axis current, and electrical angle. Because the specific process of the preprocessing module "precalculating and storing the results of finite element analysis of the motor using a finite element lookup table model to form the lookup table" is conventional in the art, it will not be detailed here.

[0157] It should be noted that since the specific process of the motor simulator 500 "using the optimized voltage equation and the optimized electromagnetic torque equation of the motor to test the motor controller of the motor" belongs to the existing technology in this field, the specific process will not be repeated here.

[0158] In some embodiments, obtaining the optimized voltage equation of the motor using an analytical model, and / or obtaining the optimized electromagnetic torque equation of the motor using an analytical model, includes:

[0159] Based on harmonic analysis, the order reduction processing is performed on the analytical models of the d-axis magnetic flux and the q-axis magnetic flux to obtain the analytical models of the d-axis magnetic flux and the q-axis magnetic flux after the order reduction processing respectively;

[0160] The optimized voltage equation of the motor is obtained by using the analytical models of the d-axis flux and the q-axis flux after the order reduction processing, and / or the optimized electromagnetic torque equation of the motor is obtained by using the analytical models of the d-axis flux and the q-axis flux after the order reduction processing.

[0161] It should be noted that the steps executed by the flux reconstruction module, the steps executed by the analytical model construction module, and the steps executed by the motor model construction module are roughly the same as the specific processing procedures and technical effects of step S100, step S200, and step S300 of the aforementioned method, respectively, so they will not be repeated here.

[0162] Some embodiments of the present application further disclose a computer-readable storage medium, including a program, which can be executed by a processor to implement the method described in any embodiment of the present invention.

[0163] This document is described with reference to various exemplary embodiments. However, those skilled in the art will recognize that changes and modifications may be made to the exemplary embodiments without departing from the scope of this document. For example, the various operational steps and components used to perform the operational steps may be implemented in different ways (e.g., one or more steps may be deleted, modified, or incorporated into other steps) depending on the specific application or considering any number of cost functions associated with the operation of the system.

[0164] In the above embodiments, all or part of the embodiments may be implemented through software, hardware, firmware, or any combination thereof. Furthermore, as will be appreciated by those skilled in the art, the principles herein may be embodied in a computer program product on a computer-readable storage medium pre-installed with computer-readable program code. Any tangible, non-transitory computer-readable storage medium may be used, including magnetic storage devices (hard disks, floppy disks, etc.), optical storage devices (CD-ROMs, DVDs, Blu-ray discs, etc.), flash memory, and / or the like. These computer program instructions may be loaded onto a general-purpose computer, a special-purpose computer, or other programmable data processing device to form a machine, such that the instructions executed on the computer or other programmable data processing device can generate a device that implements a specified function. These computer program instructions may also be stored in a computer-readable memory, which can instruct the computer or other programmable data processing device to operate in a specific manner, such that the instructions stored in the computer-readable memory can form an article of manufacture, including an implementation device that implements a specified function. The computer program instructions may also be loaded onto a computer or other programmable data processing device, thereby causing the computer or other programmable device to execute a series of operational steps to generate a computer-implemented process, such that the instructions executed on the computer or other programmable device can provide the steps for implementing the specified function.

[0165] Although the principles of this invention have been shown in various embodiments, many modifications of structure, arrangement, proportion, elements, materials and components that are particularly suitable for specific environments and operational requirements can be used without departing from the principles and scope of this invention. The above modifications and other changes or amendments are intended to be included within the scope of this invention.

[0166] The foregoing detailed description has been described with reference to various embodiments. However, those skilled in the art will recognize that various modifications and changes can be made without departing from the scope of this disclosure. Therefore, the present disclosure will be considered in an illustrative rather than a restrictive sense, and all such modifications will be included within its scope. Similarly, the advantages, other advantages and solutions to the problems of the various embodiments have been described above. However, the benefits, advantages, solutions to the problems and any elements that can produce these, or make them more specific, should not be interpreted as critical, required or necessary. The term "comprising" and any other variants used in this article are all non-exclusive inclusions, so that a process, method, article or device that includes a list of elements includes not only these elements, but also other elements that are not explicitly listed or do not belong to the process, method, system, article or device. In addition, the term "coupled" and any other variants used in this article refer to physical connections, electrical connections, magnetic connections, optical connections, communication connections, functional connections and / or any other connections.

[0167] Those skilled in the art will recognize that many changes can be made to the details of the above embodiments without departing from the basic principles of the invention. Therefore, the scope of the present invention should be determined solely by the claims.

Claims

1. A method for testing a motor controller, characterized in that: include: Selecting an operating point of the motor and obtaining lookup table data of d-axis flux, q-axis flux, d-axis current, q-axis current, and electrical angle at each operating point from a lookup table pre-formed by a finite element lookup table model; wherein the finite element lookup table model is capable of characterizing the nonlinear characteristics of the motor, including magnetic saturation effect, cross-coupling effect, and air gap magnetic field harmonic effect; deriving an analytical model of the d-axis magnetic flux and the q-axis magnetic flux by fitting the data in the lookup table; Obtaining an optimized voltage equation of the motor using the analytical model, and / or obtaining an optimized electromagnetic torque equation of the motor using the analytical model; The motor simulator tests the motor controller of the motor using the optimized voltage equation of the motor and the optimized electromagnetic torque equation of the motor.

2. The method according to claim 1, wherein The method of fitting the lookup table data to obtain the analytical model of the d-axis magnetic flux and the q-axis magnetic flux includes: Performing Fourier series expansion on the d-axis magnetic flux and the q-axis magnetic flux respectively using the lookup table data to obtain the first N Fourier series of the d-axis magnetic flux and the q-axis magnetic flux; Using the d-axis current and the q-axis current, a polynomial fit is performed on the Fourier coefficients of the first N Fourier series to obtain an approximate expression for the Fourier coefficients; Utilizing the approximate expression of the Fourier coefficient and the first N terms of the Fourier series, an analytical model of the d-axis magnetic flux and the q-axis magnetic flux is obtained; Among them, the expressions of the first N Fourier series of the d-axis magnetic flux and the q-axis magnetic flux are respectively: in, θ e Indicates the electrical angle of the motor, They represent the Fourier coefficients of the nth cosine component and sine component of the Fourier series of the d-axis magnetic flux at the mth operating point, and They represent the Fourier coefficients of the nth cosine component and sine component of the Fourier series of the q-axis magnetic flux at the mth operating point, respectively, and T represents θ e cycle.

3. The method according to claim 2, wherein The approximate expression of the Fourier coefficient is: Among them, a n_d and b n_d They represent the Fourier coefficients of the nth cosine component and sine component of the Fourier series of the d-axis magnetic flux obtained by polynomial fitting, where a n_q and b n_q They represent the Fourier coefficients of the nth cosine component and sine component of the Fourier series of the q-axis magnetic flux obtained by polynomial fitting, and Respectively represent a n_d 、a n_q 、b n_d and b n_q The coefficient array of the fitting polynomial, X(i d ,i q ) represents the d-axis current i d and q-axis current i q The polynomial basis formed; M represents the highest order of the polynomial basis. The larger the value of M, the smaller the difference between the analytical model of the d-axis magnetic flux and the q-axis magnetic flux and the lookup table data of the d-axis magnetic flux and the q-axis magnetic flux respectively. Represents the coefficient arrays respectively The coefficients of Represents the coefficient arrays respectively The coefficients of Represents the coefficient arrays respectively The coefficients of Represents the coefficient arrays respectively The coefficients of .

4. The method according to claim 3, wherein The expressions of the analytical models of the d-axis magnetic flux and the q-axis magnetic flux are: Among them, C(θ e ), S(θ e ), A d 、A q 、B d and B q The expressions are:

5. The method according to claim 4, wherein The step of obtaining the optimized voltage equation of the motor by using the analytical model, and / or obtaining the optimized electromagnetic torque equation of the motor by using the analytical model, includes: Based on harmonic analysis, the order reduction processing is performed on the analytical models of the d-axis magnetic flux and the q-axis magnetic flux to obtain the analytical models of the d-axis magnetic flux and the q-axis magnetic flux after the order reduction processing respectively; Obtaining an optimized voltage equation of the motor using the analytical models of the d-axis flux and the q-axis flux after the order reduction processing, and / or obtaining an electromagnetic torque equation of the motor using the analytical models of the d-axis flux and the q-axis flux after the order reduction processing; Among them, the analytical model of the d-axis magnetic flux and the q-axis magnetic flux after the order reduction process is C(θ e ), S(θ e ), A d 、A q 、B d and B q The expressions are: And N0=N / 6.

6. The method according to claim 5, wherein The method of obtaining the optimized voltage equation of the motor by using the analytical model of the d-axis flux and the q-axis flux after the order reduction process includes: Substituting the analytical models of the d-axis flux and the q-axis flux after the order reduction process into the first expression of the voltage equation, the second expression of the voltage equation is obtained; wherein the first expression of the voltage equation is: u d and u q They represent the d-axis component and q-axis component of the output voltage of the drive unit in the motor, R s Represents the phase resistance of the motor, ω e Indicates the electrical angular velocity of the motor; Performing full differentiation on the analytical models of the d-axis flux linkage and the q-axis flux linkage after the order reduction process to obtain analytical models of the d-axis flux linkage and the q-axis flux linkage after the full differentiation process; Substituting the analytical model of the d-axis flux and the q-axis flux after the full differentiation into the second expression of the voltage equation to obtain the optimized voltage equation of the motor; Among them, the expression of the voltage equation of the motor after optimization is: a=C(θ e )A d dX d +S(θ e )B d dX d b=C(θ e )A d dX q +S(θ e )B d dX q c=u d -R s i d -{C'(θ e )A d X(i d ,i q )ω e +S'(θ e )B d X(i d ,i q )ω e }+{C(θ e )A q X(i d ,i q )ω e +S(θ e )B q X(i d ,i q )ω e } where d = C(θ e )A q dX d + S(θ e )B q dX d ; e=C(θ e )A q dX q +S(θ e )B q dX q f=u q -R s i q -{C'(θ e )A q X(i d ,i q )ω e +S'(θ e )B q X(i d ,i q )ω e }-{C(θ e )A d X(i d ,i q )ω e +S(θ e )B d X(i d ,i q )ω e } dX d and dX q Respectively represent X(i d ,i q ) About id and i q The differential of C′(θ e )S′(θ e ) respectively represent the C(θ e ) and S(θ e ) in θ e Find the derivative.

7. The method according to claim 5, wherein The electromagnetic torque equation of the motor is obtained by using the analytical model of the d-axis flux and the q-axis flux after the order reduction process, including: The first expression of the electromagnetic torque equation is obtained by using the expression of magnetic co-energy and the relationship between electromagnetic torque and magnetic co-energy; wherein, the expression of magnetic co-energy is: in, i′ d Refers to the i d , i′ q Refers to the i q ; The first expression of the electromagnetic torque equation is: P n Indicates the number of pole pairs of the motor; The optimized electromagnetic torque equation of the motor is obtained by using the expression of the cogging torque of the motor and the first expression of the electromagnetic torque equation; wherein the expression of the cogging torque is obtained by pre-fitting, and the expression of the cogging torque is: T cog (θ e )=a1sin(b1x+c1); a1, b1 and c1 are the fitting coefficients of the cogging torque, and x represents the electrical angle; the electromagnetic torque equation of the motor after optimization is: T e =T e1 +T cog 。 8. A motor controller test system, characterized in that: include: a preprocessing module configured to precalculate and store results of a finite element analysis of the motor using a finite element lookup table model to form a lookup table; wherein the finite element lookup table model is capable of characterizing nonlinear characteristics of the motor, including magnetic saturation, cross-coupling effects, and air gap magnetic field harmonic effects; a flux reconstruction module configured to select an operating point of the motor and obtain, from the lookup table, the d-axis flux, the q-axis flux, the d-axis current, the q-axis current, and the electrical angle at each operating point; an analytical model building module configured to obtain an analytical model of the d-axis magnetic flux and the q-axis magnetic flux by fitting the data in the lookup table; a motor model building module, configured to obtain an optimized voltage equation of the motor using the analytical model, and / or to obtain an optimized electromagnetic torque equation of the motor using the analytical model; The motor simulator is configured to test the motor controller of the motor by using the optimized voltage equation of the motor and the optimized electromagnetic torque equation of the motor.

9. The test system according to claim 8, wherein: The step of obtaining the optimized voltage equation of the motor by using the analytical model, and / or obtaining the optimized electromagnetic torque equation of the motor by using the analytical model, includes: Based on harmonic analysis, the order reduction processing is performed on the analytical models of the d-axis magnetic flux and the q-axis magnetic flux to obtain the analytical models of the d-axis magnetic flux and the q-axis magnetic flux after the order reduction processing respectively; The optimized voltage equation of the motor is obtained by using the analytical models of the d-axis flux and the q-axis flux after the order reduction processing, and / or the optimized electromagnetic torque equation of the motor is obtained by using the analytical models of the d-axis flux and the q-axis flux after the order reduction processing.

10. A computer-readable storage medium, characterized in that The method comprises a program which can be executed by a processor to implement the method according to any one of claims 1 to 7.

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