A MTPA control method and related device for a permanent magnet synchronous motor

Abstract

The present invention discloses a MTPA control method and related devices for a permanent magnet synchronous motor, belonging to the technical field of motor control. The method comprises: establishing a current angle target function of the motor to be controlled based on the electromagnetic torque and stator current of the motor to be controlled; performing polynomial fitting on the current angle target function of the motor to be controlled to obtain a polynomial description of the current angle target function; performing an explicit description of the polynomial description of the current angle target function based on a Kolmogorov-Arnold network, obtaining and solving an interpretable target function, and obtaining an optimal current angle of the motor to be controlled; inputting the optimal current angle of the motor to be controlled into an MTPA control module of the motor to be controlled, and performing MTPA control on the motor to be controlled. The present invention realizes accurate calculation of the optimal current angle of the motor to be controlled, can ensure optimal distribution of the direct-axis current and the quadrature-axis current of the motor to be controlled, and achieves accurate control of the dynamic performance of the permanent magnet synchronous motor.

Description

Technical Field

[0001] The present invention belongs to the technical field of motor control, and in particular relates to a MTPA control method of a permanent magnet synchronous motor and a related device. Background Art

[0002] A permanent magnet synchronous motor (PMSM) is a synchronous motor that uses permanent magnets to generate a magnetic field. It plays a vital role in the electrical field. In particular, in the field of electric aviation, PMSM has become the preferred motor type for electric aircraft due to its low energy consumption, fast-response acceleration performance and extended flight endurance. Depending on the position of the permanent magnet material on the motor rotor, permanent magnet synchronous motors can be divided into inner-mounted permanent magnet synchronous motors (IPMSM) and surface-mounted permanent magnet synchronous motors (SPMSM). Compared with SPMSM, IPMSM has higher torque and power density and a wider speed adjustment range, making it more advantageous in the field of electric aircraft.

[0003] Currently, the control of permanent magnet synchronous motors generally includes a zero direct-axis control strategy and a maximum torque per ampere (MTPA) control strategy. Since the electromagnetic torque in a permanent magnet synchronous motor is mainly related to the direct-axis (d-axis) current, and the reluctance torque is related to both the d-axis current and the quadrature-axis (q-axis) current, the zero direct-axis control strategy will cause the reluctance torque to drop to zero, thereby reducing the output torque.

[0004] In contrast, the MTPA control strategy optimizes the distribution of d-axis current and q-axis current to enable the motor to output maximum electromagnetic torque while keeping the stator current amplitude fixed. Therefore, as an efficient control technology, the MTPA control strategy is widely used in the field of electric aircraft to ensure that the copper loss of permanent magnet synchronous motors is minimized during operation, thereby improving overall operating efficiency and flight stability, and bringing excellent performance and efficiency to the drive system of electric aircraft.

[0005] In the MTPA control strategy, its goal is to find the optimal current angle under a given stator current to maximize the output torque of the motor; wherein, the optimal current angle is called the MTPA angle; since the operating point of the MTPA angle will change with factors such as temperature, magnetic saturation and external disturbances during the actual operation of the permanent magnet synchronous motor; in view of this, parameter-based methods and search-based methods are generally used in the existing technology to obtain the MTPA angle, but the above methods rely heavily on complex mathematical models and signal injection techniques, and have problems such as low computational efficiency, poor interpretability and difficulty in scalability; specifically, the parameter-based method is directly calculated by equations and formulas, which is highly dependent on the availability of precise parameters and is easily affected by the specific working conditions and environmental factors of the electric aircraft; the search-based method relies on iterative optimization calculations or is obtained by injecting virtual high-frequency signals, and has a low computational speed and requires a large amount of computing resources. Summary of the Invention

[0006] In response to the technical problems existing in the prior art, the present invention provides a MTPA control method and related devices for a permanent magnet synchronous motor to solve the technical problems that the method for obtaining the MTPA angle in the prior art heavily relies on complex mathematical models and signal injection technology, resulting in low computational efficiency, poor interpretability and difficulty in scalability.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] The present invention provides a MTPA control method for a permanent magnet synchronous motor, comprising:

[0009] Obtain the electromagnetic torque and stator current of the motor to be controlled;

[0010] Taking the maximization of the ratio of the electromagnetic torque and stator current of the motor to be controlled as the goal, the current angle objective function of the motor to be controlled is established;

[0011] Based on Taylor expansion, a polynomial fitting is performed on the current angle objective function of the motor to be controlled to obtain a polynomial description of the current angle objective function;

[0012] According to the Kolmogorov-Arnold network, the polynomial description of the current angle objective function is explicitly described to obtain an interpretable objective function;

[0013] Solve the interpretable objective function to obtain the optimal current angle of the motor to be controlled;

[0014] Based on the optimal current angle of the motor to be controlled, MTPA control is performed on the motor to be controlled.

[0015] Furthermore, the process of obtaining the electromagnetic torque and stator current of the motor to be controlled includes:

[0016] According to the nonlinear equation of the motor to be controlled, the MTPA control logic rules of the motor to be controlled are established;

[0017] According to the MTPA control logic rule of the motor to be controlled and based on the preset current angle test value, the electromagnetic torque and stator current of the motor to be controlled are obtained.

[0018] Furthermore, the nonlinear equation of the motor to be controlled includes a steady-state voltage equation of the motor to be controlled and a torque equation of the motor to be controlled;

[0019] The steady-state voltage equation of the motor to be controlled is as follows:

[0020]

[0021]

[0022]

[0023]

[0024] in, is the equivalent voltage of the motor to be controlled on the direct axis; is the stator resistance of the motor to be controlled; is the equivalent current of the motor to be controlled on the direct axis; is the equivalent inductance of the motor to be controlled on the direct axis; is the equivalent current of the motor to be controlled on the quadrature axis; For time; is the number of pole pairs of the motor to be controlled; is the mechanical rotor speed of the motor to be controlled; is the equivalent inductance of the motor to be controlled on the quadrature axis; is the equivalent voltage of the motor to be controlled on the quadrature axis; is the permanent magnet flux of the motor to be controlled; is the stator current of the motor to be controlled; is the current angle of the motor to be controlled;

[0025] The torque equation of the motor to be controlled is as follows:

[0026]

[0027]

[0028] in, is the electromagnetic torque of the motor to be controlled.

[0029] Furthermore, the current angle objective function of the motor to be controlled is as follows:

[0030]

[0031] in, is the current angle objective function of the motor to be controlled; is the current angle of the motor to be controlled; is the electromagnetic torque of the motor to be controlled; is the stator current of the motor to be controlled.

[0032] Furthermore, the polynomial description of the current angle objective function is as follows:

[0033]

[0034] in, is the polynomial description of the current angle objective function. Coefficient of order expansion term; is the polynomial description of the current angle objective function. Coefficient of order expansion term; is the coefficient of the first-order expansion term in the polynomial description of the current angle objective function; is the coefficient of the zeroth-order expansion term in the polynomial description of the current angle objective function; is the expansion order, .

[0035] Further, the interpretable objective function is as follows:

[0036]

[0037] in, is an interpretable objective function; is the parameter describing the baseline of the current angle objective function; Parameters that describe the harmonic and periodic behavior of the motor model; is a parameter that describes the effect of magnetic saturation on the motor model.

[0038] Furthermore, the process of solving the interpretable objective function to obtain the optimal current angle of the motor to be controlled includes:

[0039] Solve the first-order derivative of the interpretable objective function to obtain the first-order derivative of the objective function with respect to the current angle;

[0040] The first-order derivative of the objective function with respect to the current angle is set to zero, and the optimal current angle of the motor to be controlled is calculated.

[0041] The present invention also provides an MTPA control system for a permanent magnet synchronous motor, comprising:

[0042] A data acquisition module, used to obtain the electromagnetic torque and stator current of the motor to be controlled;

[0043] A function building module is used to establish a current angle objective function of the motor to be controlled with the goal of maximizing the ratio of the electromagnetic torque and the stator current of the motor to be controlled;

[0044] A polynomial description module is used to perform polynomial fitting on the current angle target function of the motor to be controlled based on Taylor expansion to obtain a polynomial description of the current angle target function;

[0045] An explicit description module is used to explicitly describe the polynomial description of the current angle objective function based on the Kolmogorov-Arnold network to obtain an interpretable objective function;

[0046] Function solving module solves the interpretable objective function to obtain the optimal current angle of the motor to be controlled;

[0047] The input control module is used to perform MTPA control on the motor to be controlled based on the optimal current angle of the motor to be controlled.

[0048] The present invention also provides an electronic device, comprising:

[0049] a processor suitable for executing a computer program;

[0050] A computer-readable storage medium stores a computer program, and when the computer program is executed by the processor, the MTPA control method of the permanent magnet synchronous motor is executed.

[0051] The present invention also provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the MTPA control method of the permanent magnet synchronous motor is implemented.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] The present invention provides a MTPA control method for a permanent magnet synchronous motor. The method uses Taylor expansion to perform polynomial fitting on the current angle objective function of the motor to be controlled, and explicitly describes the polynomial description of the current angle objective function through a Kolmogorov-Arnold network, thereby accurately calculating the optimal current angle of the motor to be controlled. The MTPA control of the motor to be controlled is performed with the optimal current angle, which can ensure that the direct-axis current and the quadrature-axis current of the motor to be controlled are optimally distributed, thereby achieving precise control of the dynamic performance of the permanent magnet synchronous motor. The present invention does not require the inductance diagram or permanent magnet flux parameters of the motor, can effectively reduce the dependence on complex mathematical models and high-frequency signal injection, and has the advantages of strong interpretability, high scalability, and high efficiency and simplicity. At the same time, it can reduce the impact of motor parameter changes and enhance the robustness of the MTPA control method. It also improves load disturbance and transient response, further reduces copper loss, and improves the operating efficiency of the permanent magnet synchronous motor.

[0054] The MTPA control system, electronic device, and computer-readable storage medium of the permanent magnet synchronous motor provided by the present invention have all the advantages of the MTPA control method of the permanent magnet synchronous motor described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0056] Figure 1 Flowchart of the MTPA control method for the permanent magnet synchronous motor provided in Example 1;

[0057] Figure 2 Schematic diagram of the two-dimensional increase and decrease trend of the current angle in Example 1;

[0058] Figure 3 Schematic diagram of the three-dimensional increase and decrease trend of the current angle in Example 1;

[0059] Figure 4 A structural block diagram of the MTPA control system of the permanent magnet synchronous motor provided in Example 2;

[0060] Figure 5 A structural block diagram of an electronic device is provided for Example 3. DETAILED DESCRIPTION

[0061] In order to make the technical problems, technical solutions, and beneficial effects solved by this application more clearly understood, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of this application; it is obvious that the described embodiments are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of this application.

[0062] The present invention provides a MTPA control method for a permanent magnet synchronous motor, comprising the following steps:

[0063] Step 100: Obtain the electromagnetic torque and stator current of the motor to be controlled. The motor to be controlled is a permanent magnet synchronous motor, and a MTPA (Maximum Torque Per Ampere) control module is provided in the motor to be controlled.

[0064] Step 200 : Establish a current angle objective function of the motor to be controlled with the goal of maximizing the ratio of the electromagnetic torque and the stator current of the motor to be controlled.

[0065] Step 300: Based on Taylor expansion, perform polynomial fitting on the current angle target function of the motor to be controlled to obtain a polynomial description of the current angle target function.

[0066] Step 400: Based on Kolmogorov-Arnold Networks (KANs), the polynomial description of the current angle objective function is explicitly described to obtain an interpretable objective function.

[0067] Step 500: Solve the interpretable objective function to obtain the optimal current angle of the motor to be controlled.

[0068] Step 600: Perform MTPA control on the motor to be controlled based on the optimal current angle of the motor to be controlled.

[0069] The present invention also provides an MTPA control system for a permanent magnet synchronous motor, comprising a data acquisition module, a function construction module, a polynomial description module, a display description module, a function solving module and an input control module.

[0070] A data acquisition module is used to obtain the electromagnetic torque and stator current of the motor to be controlled; a function construction module is used to establish the current angle target function of the motor to be controlled with the goal of maximizing the ratio of the electromagnetic torque and stator current of the motor to be controlled; a polynomial description module is used to perform polynomial fitting on the current angle target function of the motor to be controlled based on Taylor expansion to obtain a polynomial description of the current angle target function; an explicit description module is used to perform an explicit description of the polynomial description of the current angle target function based on the Kolmogorov-Arnold network to obtain an interpretable target function; a function solving module is used to solve the interpretable target function to obtain the optimal current angle of the motor to be controlled; an input control module is used to perform MTPA control on the motor to be controlled based on the optimal current angle of the motor to be controlled.

[0071] The MTPA control method and system of a permanent magnet synchronous motor described in the present invention first establish a current angle target function of the motor to be controlled based on the electromagnetic torque and stator current of the motor to be controlled, then use Taylor expansion to perform polynomial fitting on the current angle target function of the motor to be controlled, and explicitly describe the polynomial description of the current angle target function through a Kolmogorov-Arnold network to obtain an interpretable target function. Then, by solving the interpretable target function, accurate calculation of the optimal current angle of the motor to be controlled is achieved, and MTPA control of the motor to be controlled is performed at the optimal current angle, which can ensure that the direct-axis current and the quadrature-axis current of the motor to be controlled are optimally distributed, thereby achieving precise control of the dynamic performance of the permanent magnet synchronous motor.

[0072] In the present invention, when the polynomial description of the current angle objective function is explicitly described by the Kolmogorov-Arnold network, the multi-layer nonlinear activation function structure of the Kolmogorov-Arnold network is utilized to fit the relationship between the optimal current angle and the motor parameters in a more intuitive manner, thereby improving the interpretability of the current angle objective function of the motor to be controlled; secondly, the architecture of the Kolmogorov-Arnold network allows the addition or reduction of the number of layers and the number of neurons to adapt to motor control tasks of different complexities, and has high flexibility and scalability; in addition, it can greatly reduce the computational complexity and the required test data flow, and thus can quickly learn and fit an interpretable objective function from a small amount of data, thereby reducing the number and cost of actual vehicle tests of the motor to be controlled; in addition, it has real-time response control requirements and rapid estimation of the optimal current angle, which is suitable for the rapid dynamic response requirements of permanent magnet synchronous motors in electric aircraft.

[0073] The following further explains the MTPA control method of the permanent magnet synchronous motor provided by the present invention with some specific embodiments:

[0074] Example 1

[0075] In this embodiment 1, the MTPA control process of the internal permanent magnet synchronous motor used in the electric aircraft is taken as an example; Figure 1 As shown, a MTPA control method for a permanent magnet synchronous motor is provided, comprising the following steps:

[0076] Step 1: Obtain the electromagnetic torque and stator current of the motor to be controlled. The motor to be controlled is an interior permanent magnet synchronous motor (IPMS) used in electric aircraft. The IPMMS is equipped with a MTPA control module. The MTPA control module is configured to control the IPMMS based on the MTPA angle.

[0077] It should be explained in detail that the process of obtaining the electromagnetic torque and stator current of the motor to be controlled is as follows:

[0078] Step 11: Establishing MTPA control logic rules for the motor to be controlled based on the nonlinear equations of the motor to be controlled, wherein the nonlinear equations of the motor to be controlled include the steady-state voltage equation and the torque equation of the motor to be controlled.

[0079] Specifically, the steady-state voltage equation of the motor to be controlled is as follows:

[0080]

[0081]

[0082]

[0083]

[0084] in, is the equivalent voltage of the motor to be controlled on the direct axis; is the stator resistance of the motor to be controlled; is the equivalent current of the motor to be controlled on the direct axis; is the equivalent inductance of the motor to be controlled on the direct axis; is the equivalent current of the motor to be controlled on the quadrature axis; For time; is the number of pole pairs of the motor to be controlled; is the mechanical rotor speed of the motor to be controlled; is the equivalent inductance of the motor to be controlled on the quadrature axis; is the equivalent voltage of the motor to be controlled on the quadrature axis; is the permanent magnet flux of the motor to be controlled; is the stator current of the motor to be controlled; is the current angle of the motor to be controlled;

[0085] Specifically, the torque equation of the motor to be controlled is as follows:

[0086]

[0087]

[0088] in, is the electromagnetic torque of the motor to be controlled.

[0089] It should be noted that the nonlinear equations of the motor to be controlled can reflect the complex electromagnetic relationships inside the motor to be controlled, such as the interaction between electromagnetic torque, stator current, permanent magnet flux linkage and current angle; since the MTPA control strategy of the permanent magnet synchronous motor aims to achieve high-efficiency operation of the permanent magnet synchronous motor under different working conditions, by reasonably allocating the direct-axis current and the quadrature-axis current, the current consumed by the permanent magnet synchronous motor when outputting the same torque is minimized, thereby improving the efficiency and performance of the permanent magnet synchronous motor; based on the nonlinear equations of the motor to be controlled, the MTPA control logic rules of the motor to be controlled are established, which can accurately determine the current distribution strategy according to the real-time operating status of the motor, and provide a theoretical basis and control criteria for accurately obtaining the electromagnetic torque and stator current; secondly, based on the MTPA control logic rules of the motor to be controlled, the current distribution of the motor to be controlled can be dynamically adjusted according to the torque and speed requirements of the electric aircraft for the motor to be controlled under different working conditions, to ensure efficient and stable operation of the motor and meet the power requirements of the electric aircraft.

[0090] Step 12: Obtain the electromagnetic torque and stator current of the motor to be controlled based on the preset current angle test value according to the MTPA control logic rules of the motor to be controlled. Specifically, according to the MTPA control logic rules of the motor to be controlled, the preset current angle test value is used as a test signal, and data is collected from the controller speed loop and torque sensor of the motor to be controlled to obtain the electromagnetic torque and stator current of the motor to be controlled. When collecting data from the controller speed loop of the motor to be controlled, the stator current of the motor to be controlled can be obtained; when collecting data from the torque sensor of the motor to be controlled, the electromagnetic torque of the motor to be controlled can be obtained.

[0091] It should be noted that the controller speed loop of the motor to be controlled is set in the control module of the motor to be controlled and is associated with the drive circuit of the motor to be controlled; the working principle of the controller speed loop includes: based on feedback control theory, collecting the speed information of the motor to be controlled in real time, and comparing it with the preset speed reference value; when there is a deviation between the real-time collected speed information of the motor to be controlled and the preset speed reference value, the controller speed loop will adjust the output control signal according to the preset control method, and then change the input current of the motor to maintain the speed stability of the motor to be controlled; when collecting data from the controller speed loop of the motor to be controlled, since the controller speed loop has the characteristic of controlling the motor current, the stator current of the motor to be controlled can be obtained by analyzing and calculating the control signal output by the controller speed loop.

[0092] It should also be noted that the torque sensor of the motor to be controlled is installed between the output shaft of the motor to be controlled and the external load, and can accurately measure the torque transmitted by the output shaft of the motor to be controlled; preferably, the torque sensor of the motor to be controlled is a strain gauge torque sensor; the working principle of the strain gauge torque sensor includes: when the motor to be controlled is working, the output shaft will generate torque, and the strain gauge torque sensor converts the torque into an electrical signal output based on the resistance strain effect, thereby obtaining the electromagnetic torque of the motor to be controlled.

[0093] Step 2: With the goal of maximizing the ratio of the electromagnetic torque and stator current of the motor to be controlled, establish the current angle objective function of the motor to be controlled. The current angle objective function of the motor to be controlled is as follows:

[0094]

[0095] in, is the current angle objective function of the motor to be controlled; is the current angle of the motor to be controlled; is the electromagnetic torque of the motor to be controlled; is the stator current of the motor to be controlled.

[0096] It should be noted that in the interior permanent magnet synchronous motor, both the permanent magnet torque and the reluctance torque depend on the current angle. For a given stator current, the electromagnetic torque of the interior permanent magnet synchronous motor is a function of the current angle. When the current angle increases from 0 to In the process, the function curve of the current angle shows a trend of increasing first and then decreasing, as shown in the attached figure. Figure 2-3 As shown; attached Figure 2 A two-dimensional diagram of the increase and decrease trend of the current angle is given in the appendix. Figure 3 The three-dimensional increase and decrease trend diagram of the current angle is given in the attached figure. Figure 2 It can be seen from the figure that when the stator current is 5A, 10A and 15A, the function curve of the current angle shows a trend of first increasing and then decreasing. At the same time, the actual measurement experiment proves that the trend of the function curve of the current angle first increasing and then decreasing is valid under different conditions, as shown in the attached figure. Figure 3 As shown; therefore, there is a specific current angle that can make the function of the current angle reach the maximum value; that is, when the ratio of the electromagnetic torque and the stator current of the motor to be controlled is maximized, the current angle objective function of the motor to be controlled is established; based on the extreme value theorem, the vertex of the current angle objective function of the motor to be controlled is the optimal current angle of the motor to be controlled.

[0097] Step 3: Based on Taylor expansion, perform polynomial fitting on the current angle objective function of the motor to be controlled to obtain a polynomial description of the current angle objective function. The polynomial description of the current angle objective function is as follows:

[0098]

[0099] in, is the polynomial description of the current angle objective function. Coefficient of order expansion term; is the polynomial description of the current angle objective function. Coefficient of order expansion term; is the coefficient of the first-order expansion term in the polynomial description of the current angle objective function; is the coefficient of the zeroth-order expansion term in the polynomial description of the current angle objective function; is the expansion order, .

[0100] Specifically, based on Taylor expansion, a polynomial fitting is performed on the current angle target function of the motor to be controlled. In the process of obtaining a polynomial description of the current angle target function, the least squares method or a predefined error function method is used to perform Taylor expansion to perform polynomial fitting on the current angle target function of the motor to be controlled.

[0101] The process of using the least squares method to perform Taylor expansion is applicable to the low-order case where the expansion order is 2 or 3. The process of using the least squares method to perform Taylor expansion is as follows:

[0102]

[0103] in, is the coefficient of the first-order expansion term in the polynomial description of the current angle objective function; is the coefficient of the second-order expansion term in the polynomial description of the current angle objective function; is the coefficient of the second-order expansion term in the polynomial description of the current angle objective function.

[0104] The Taylor expansion is performed based on a predefined error function method, which is applicable to high-order cases where the expansion order is greater than 3. The process of performing the Taylor expansion based on the predefined error function method is as follows:

[0105] Based on the preset current angle test value, the preset performance parameters of the motor to be controlled are calculated; wherein, the preset performance parameters of the motor to be controlled are, for example, electromagnetic power or motor efficiency; according to the preset current angle test value and the preset performance parameters of the motor to be controlled, an error function is constructed to obtain a predefined error function; the partial derivatives of the predefined error function with respect to the expansion term coefficients are calculated, and the partial derivatives are set to zero to obtain a system of linear equations; the system of linear equations is solved to obtain the expansion term coefficients in the polynomial description of the current angle objective function; finally, according to the expansion term coefficients in the polynomial description of the current angle objective function, the polynomial description of the current angle objective function can be obtained.

[0106] Among them, the predefined error function is:

[0107]

[0108] in, is a predefined error function; For the A preset current angle test value; Based on the Preset performance parameters of the motor to be controlled calculated based on a preset current angle test value; The number of preset current angle test values.

[0109] Step 4: Based on the Kolmogorov-Arnold network, the polynomial description of the current angle objective function is explicitly described to obtain an interpretable objective function. The interpretable objective function is as follows:

[0110]

[0111] in, is an interpretable objective function; It is a parameter that describes the baseline of the current angle objective function and is used to reflect the characteristics of the current angle objective function in the basic state, so as to determine the basic trend and approximate range of the current angle objective function; Parameters that describe the harmonic and periodic behavior of the motor model, used to quantify the impact of the harmonic and periodic characteristics generated by the motor during operation on the current angle objective function; It is a parameter that describes the influence of magnetic saturation on the motor model and is used to characterize the effect of magnetic saturation on the current angle objective function.

[0112] Specifically, based on the Kolmogorov-Arnold network, the polynomial description of the current angle objective function is explicitly described to obtain an interpretable objective function as follows:

[0113] Based on the coefficients of the expanded terms in the polynomial description of the current angle objective function and the preset sample data, a feature vector is constructed; wherein the preset sample data includes the current angle of the motor to be controlled and the electromagnetic torque of the motor to be controlled; the feature vector is input into the Kolmogorov-Arnold network to fit the parameters describing the baseline of the current angle objective function in the interpretable objective function. , parameters describing the harmonic and periodic behavior of the motor model and parameters describing the effects of magnetic saturation on the motor model .

[0114] It should be noted that a polynomial is used to model the current angle objective function of the motor to be controlled, based on preset experimental data, and curve fitting is performed using the Kolmogorov-Arnold network to identify the parameters in the interpretable objective function; when the current angle objective function of the motor to be controlled is expressed in the form of a polynomial, and the polynomial description of the current angle objective function is explicitly described by the Kolmogorov-Arnold network, the optimal current angle of the motor to be controlled can be analyzed.

[0115] It should also be noted that the eigenvector is input into the Kolmogorov-Arnold network to fit the parameters describing the baseline of the current angle objective function in the interpretable objective function. , parameters describing the harmonic and periodic behavior of the motor model and parameters describing the effects of magnetic saturation on the motor model In the process, the error between the output of the Kolmogorov-Arnold network and the parameter target curve is calculated by the back propagation algorithm, and the parameters of the Kolmogorov-Arnold network are adjusted according to the error; through continuous iteration, until the error converges to the preset range; wherein, the parameter target curve is the coefficient of the expansion term in the polynomial description of the current angle target function and the parameter describing the baseline of the current angle target function , parameters describing the harmonic and periodic behavior of the motor model and parameters describing the effects of magnetic saturation on the motor model target curve.

[0116] Step 5: Solve the interpretable objective function to obtain the optimal current angle of the motor to be controlled. Specifically, the process of solving the interpretable objective function to obtain the optimal current angle of the motor to be controlled includes:

[0117] Step 51: Solve the first-order derivative of the interpretable objective function to obtain the first-order derivative of the objective function with respect to the current angle.

[0118] Step 52: Set the first-order derivative of the objective function with respect to the current angle to zero, that is, , calculate the optimal current angle of the motor to be controlled.

[0119] Step 6: Based on the optimal current angle of the motor to be controlled, perform MTPA control on the motor to be controlled. Specifically, the optimal current angle of the motor to be controlled is input into the MTPA control module of the motor to be controlled, and MTPA control is performed on the motor to be controlled.

[0120] The MTPA control method for a permanent magnet synchronous motor described in Example 1 achieves efficient MTPA control by accurately calculating the optimal current angle of the motor to be controlled and performing MTPA control on the motor to be controlled based on the optimal current angle, so as to output torque under optimized stator current. This can effectively reduce the additional losses caused by the high-frequency signal injection method. Among them, the Kolmogorov-Arnold network is used to quickly and accurately explicitly describe the polynomial description of the current angle objective function, which can effectively overcome the traditional MTPA control method's reliance on complex mathematical models and signal injection technology, avoiding the problems of low computational efficiency, poor interpretability, and difficulty in scalability.

[0121] In this embodiment 1, the multi-layer nonlinear activation function structure of the Kolmogorov-Arnold network is utilized to fit the relationship between the optimal current angle and the motor parameters in a more intuitive manner. Specifically, each layer of the nonlinear activation function of the Kolmogorov-Arnold network can transform the input data to gradually extract key features in the input data. For example, the first layer extracts the basic linear relationship characteristics of current and torque, and the second layer, based on the first layer, explores the nonlinear relationship characteristics between the basic linear relationship characteristics of current and torque and the optimal current angle. In a layer-by-layer progressive manner, the relationship between the complex motor parameters and the optimal current angle is gradually decomposed and presented. At the same time, the Kolmogorov-Arnold network allows a clear understanding of the control law of the motor, thereby improving interpretability.

[0122] Secondly, the architecture of the Kolmogorov-Arnold network allows adding or reducing the number of layers and neurons to adapt to motor control tasks of different complexities; when determining the number of layers, for simple motor control tasks, such as the control of small, low-power permanent magnet synchronous motors, the number of layers of the Kolmogorov-Arnold network is set to 2-3; for complex motor control tasks, such as the control of large, high-power permanent magnet synchronous motors under variable working conditions, the number of layers of the Kolmogorov-Arnold network is set to 4-5 or more to fully extract and process complex features; when determining the number of neurons, a preliminary setting is made based on the dimension of the input data and the complexity of the task; for example, for cases where the input data dimension is low and the task is relatively simple, the number of neurons in each layer is small. The number of neurons can be set to a small number, such as 10-20; for situations where the input data dimension is high and the task is complex, the number of neurons in each layer can be increased accordingly, such as 50-100; then, through the cross-validation method, training is performed at different neuron number settings, and the neuron number configuration with the best performance is selected based on the training results; by flexibly adjusting the architecture of the Kolmogorov-Arnold network, it can be applied to various motor control scenarios from simple to complex, including but not limited to permanent magnet synchronous motors of different power levels and types; in addition, the network parameters of the Kolmogorov-Arnold network can be adjusted through preset machine learning methods to adapt to new control requirements and environmental changes, further enhancing the scalability of the method.

[0123] Compared with the traditional MTPA control method based on signal injection, the method described in Example 1 can significantly reduce the computational complexity and the amount of test data required; secondly, the Kolmogorov-Arnold network can quickly learn and fit an interpretable objective function from a small amount of test data, thereby reducing the number and cost of actual vehicle tests; in addition, the Kolmogorov-Arnold network can also respond to control requirements in real time and provide a fast optimal current angle estimation method to meet the requirements of electric aircraft that require fast dynamic response.

[0124] Example 2

[0125] As attached Figure 4 As shown, this embodiment 2 provides an MTPA control system for a permanent magnet synchronous motor, including a data acquisition module, a function construction module, a polynomial description module, a display description module, a function solving module and an input control module.

[0126] A data acquisition module is used to obtain the electromagnetic torque and stator current of the motor to be controlled; a function construction module is used to establish the current angle target function of the motor to be controlled with the goal of maximizing the ratio of the electromagnetic torque and stator current of the motor to be controlled; a polynomial description module is used to perform polynomial fitting on the current angle target function of the motor to be controlled based on Taylor expansion to obtain a polynomial description of the current angle target function; an explicit description module is used to perform an explicit description of the polynomial description of the current angle target function based on the Kolmogorov-Arnold network to obtain an interpretable target function; a function solving module is used to solve the interpretable target function to obtain the optimal current angle of the motor to be controlled; an input control module is used to perform MTPA control on the motor to be controlled based on the optimal current angle of the motor to be controlled.

[0127] Example 3

[0128] As attached Figure 5 As shown, this embodiment 3 provides an electronic device, including: a memory for storing a computer program; and a processor for implementing the steps of the MTPA control method of a permanent magnet synchronous motor when executing the computer program.

[0129] When the processor executes the computer program, the steps of the MTPA control method of the permanent magnet synchronous motor are implemented, for example:

[0130] The electromagnetic torque and stator current of the motor to be controlled are obtained. The motor to be controlled is a permanent magnet synchronous motor (PMSM) equipped with a MTPA control module. A current angle objective function of the motor to be controlled is established with the goal of maximizing the ratio of the electromagnetic torque to the stator current of the motor to be controlled. Based on a Taylor expansion, a polynomial fitting is performed on the current angle objective function of the motor to be controlled to obtain a polynomial description of the current angle objective function. Based on a Kolmogorov-Arnold network, the polynomial description of the current angle objective function is explicitly described to obtain an interpretable objective function. The interpretable objective function is solved to obtain the optimal current angle of the motor to be controlled. Based on the optimal current angle of the motor to be controlled, MTPA control is performed on the motor to be controlled.

[0131] Alternatively, when the processor executes the computer program, the functions of each module in the MTPA control system of the permanent magnet synchronous motor are realized, for example:

[0132] A data acquisition module is used to obtain the electromagnetic torque and stator current of the motor to be controlled; a function construction module is used to establish the current angle target function of the motor to be controlled with the goal of maximizing the ratio of the electromagnetic torque and stator current of the motor to be controlled; a polynomial description module is used to perform polynomial fitting on the current angle target function of the motor to be controlled based on Taylor expansion to obtain a polynomial description of the current angle target function; an explicit description module is used to perform an explicit description of the polynomial description of the current angle target function based on the Kolmogorov-Arnold network to obtain an interpretable target function; a function solving module is used to solve the interpretable target function to obtain the optimal current angle of the motor to be controlled; an input control module is used to perform MTPA control on the motor to be controlled based on the optimal current angle of the motor to be controlled.

[0133] Exemplarily, the computer program may be divided into one or more modules / units, which are stored in the memory and executed by the processor to implement the present invention. The one or more modules / units may be a series of computer program instruction segments capable of implementing preset functions, and the instruction segments are used to describe the execution process of the computer program in the electronic device.

[0134] For example, the computer program can be divided into a data acquisition module, a function construction module, a polynomial description module, a display description module, a function solving module and an input control module, and the specific functions of each module are as follows: a data acquisition module, used to obtain the electromagnetic torque and stator current of the motor to be controlled; a function construction module, used to establish the current angle target function of the motor to be controlled with the goal of maximizing the ratio of the electromagnetic torque and the stator current of the motor to be controlled; a polynomial description module, used to perform polynomial fitting on the current angle target function of the motor to be controlled based on Taylor expansion, and obtain a polynomial description of the current angle target function; an explicit description module, used to perform an explicit description of the polynomial description of the current angle target function based on the Kolmogorov-Arnold network, and obtain an interpretable target function; a function solving module, used to solve the interpretable target function to obtain the optimal current angle of the motor to be controlled; an input control module, used to perform MTPA control on the motor to be controlled based on the optimal current angle of the motor to be controlled.

[0135] The electronic device may be a computing device such as a desktop computer, laptop, PDA, or cloud server. The electronic device may include, but is not limited to, a processor and memory. Those skilled in the art will appreciate that the above are examples of electronic devices and do not constitute a limitation on electronic devices. The electronic device may include more components than those described above, or a combination of certain components, or different components. For example, the electronic device may also include input and output devices, network access devices, buses, etc.

[0136] The processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor. The processor is the control center of the electronic device, connecting all parts of the electronic device using various interfaces and lines.

[0137] The memory may be used to store the computer programs and / or modules, and the processor implements various functions of the electronic device by running or executing the computer programs and / or modules stored in the memory and calling the data stored in the memory.

[0138] The memory may primarily include a program storage area and a data storage area. The program storage area may store an operating system and at least one application required for a function (such as sound playback or image playback); the data storage area may store data generated based on the use of the mobile phone (such as audio data and a phone book). Furthermore, the memory may include high-speed random access memory (RAM) and non-volatile memory, such as a hard disk, internal memory, a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) card, a flash card, at least one disk storage device, a flash memory device, or other volatile solid-state storage device.

[0139] Example 4

[0140] This embodiment 4 also provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the steps of the MTPA control method of a permanent magnet synchronous motor are implemented.

[0141] If the module / unit integrated in the MTPA control system of the permanent magnet synchronous motor is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium.

[0142] Based on this understanding, the present invention can implement all or part of the processes in the above-mentioned MTPA control method for a permanent magnet synchronous motor by instructing related hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When executed by a processor, the computer program can implement the steps of the above-mentioned MTPA control method for a permanent magnet synchronous motor. The computer program includes computer program code, which can be in source code form, object code form, executable file, or a preset intermediate form.

[0143] The computer-readable storage medium may include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal, and software distribution medium, etc.

[0144] The above embodiment is only one of the implementation methods that can realize the technical solution of the present invention. The scope of protection claimed by the present invention is not limited only to this embodiment, but also includes changes, replacements and other implementation methods that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed by the present invention.

Claims

1. A MTPA control method for a permanent magnet synchronous motor, characterized in that: include: Obtain the electromagnetic torque and stator current of the motor to be controlled; Taking the maximization of the ratio of the electromagnetic torque and stator current of the motor to be controlled as the goal, the current angle objective function of the motor to be controlled is established; Based on Taylor expansion, a polynomial fitting is performed on the current angle objective function of the motor to be controlled to obtain a polynomial description of the current angle objective function; According to the Kolmogorov-Arnold network, the polynomial description of the current angle objective function is explicitly described to obtain an interpretable objective function; the interpretable objective function is as follows: in, is an interpretable objective function; is the current angle of the motor to be controlled; is the electromagnetic torque of the motor to be controlled; is the stator current of the motor to be controlled; is the parameter describing the baseline of the current angle objective function; Parameters that describe the harmonic and periodic behavior of the motor model; is a parameter that describes the effect of magnetic saturation on the motor model; Solve the interpretable objective function to obtain the optimal current angle of the motor to be controlled; Based on the optimal current angle of the motor to be controlled, MTPA control is performed on the motor to be controlled.

2. The MTPA control method of a permanent magnet synchronous motor according to claim 1, characterized in that: The process of obtaining the electromagnetic torque and stator current of the motor to be controlled includes: According to the nonlinear equation of the motor to be controlled, the MTPA control logic rules of the motor to be controlled are established; According to the MTPA control logic rule of the motor to be controlled and based on the preset current angle test value, the electromagnetic torque and stator current of the motor to be controlled are obtained.

3. The MTPA control method of a permanent magnet synchronous motor according to claim 2, characterized in that: The nonlinear equation of the motor to be controlled includes a steady-state voltage equation of the motor to be controlled and a torque equation of the motor to be controlled; The steady-state voltage equation of the motor to be controlled is as follows: in, is the equivalent voltage of the motor to be controlled on the direct axis; is the stator resistance of the motor to be controlled; is the equivalent current of the motor to be controlled on the direct axis; is the equivalent inductance of the motor to be controlled on the direct axis; is the equivalent current of the motor to be controlled on the quadrature axis; For time; is the number of pole pairs of the motor to be controlled; is the mechanical rotor speed of the motor to be controlled; is the equivalent inductance of the motor to be controlled on the quadrature axis; is the equivalent voltage of the motor to be controlled on the quadrature axis; is the permanent magnet flux of the motor to be controlled; is the stator current of the motor to be controlled; is the current angle of the motor to be controlled; The torque equation of the motor to be controlled is as follows: in, is the electromagnetic torque of the motor to be controlled.

4. The MTPA control method of a permanent magnet synchronous motor according to claim 1, characterized in that: The current angle objective function of the motor to be controlled is as follows: in, is the current angle objective function of the motor to be controlled.

5. The MTPA control method of a permanent magnet synchronous motor according to claim 4, characterized in that: The polynomial description of the current angle objective function is as follows: in, is the polynomial description of the current angle objective function. Coefficient of order expansion term; is the polynomial description of the current angle objective function. Coefficient of order expansion term; is the coefficient of the first-order expansion term in the polynomial description of the current angle objective function; is the coefficient of the zeroth-order expansion term in the polynomial description of the current angle objective function; is the expansion order, .

6. The MTPA control method of a permanent magnet synchronous motor according to claim 1, characterized in that: The process of solving the interpretable objective function to obtain the optimal current angle of the motor to be controlled includes: Solve the first-order derivative of the interpretable objective function to obtain the first-order derivative of the objective function with respect to the current angle; The first-order derivative of the objective function with respect to the current angle is set to zero, and the optimal current angle of the motor to be controlled is calculated.

7. A MTPA control system for a permanent magnet synchronous motor, characterized in that: include: A data acquisition module, used to obtain the electromagnetic torque and stator current of the motor to be controlled; A function building module is used to establish a current angle objective function of the motor to be controlled with the goal of maximizing the ratio of the electromagnetic torque and the stator current of the motor to be controlled; A polynomial description module is used to perform polynomial fitting on the current angle target function of the motor to be controlled based on Taylor expansion to obtain a polynomial description of the current angle target function; The explicit description module is used to explicitly describe the polynomial description of the current angle objective function based on the Kolmogorov-Arnold network to obtain an interpretable objective function; the interpretable objective function is as follows: in, is an interpretable objective function; is the current angle of the motor to be controlled; is the electromagnetic torque of the motor to be controlled; is the stator current of the motor to be controlled; is the parameter describing the baseline of the current angle objective function; Parameters that describe the harmonic and periodic behavior of the motor model; is a parameter that describes the effect of magnetic saturation on the motor model; Function solving module solves the interpretable objective function to obtain the optimal current angle of the motor to be controlled; The input control module is used to perform MTPA control on the motor to be controlled based on the optimal current angle of the motor to be controlled.

8. An electronic device, characterized in that: include: a processor suitable for executing a computer program; A computer-readable storage medium having a computer program stored therein, wherein when the computer program is executed by the processor, the MTPA control method for the permanent magnet synchronous motor according to any one of claims 1 to 6 is executed.

9. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the MTPA control method of the permanent magnet synchronous motor according to any one of claims 1 to 6 is implemented.

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