Permanent magnet synchronous motor external characteristic calibration data correction method, device and medium

Abstract

The application provides a permanent magnet synchronous motor external characteristic calibration data correction method, device and medium, relates to the permanent magnet synchronous motor calibration data processing technical field, and includes: obtaining the bus voltage and the rotating speed under the calibration condition, and obtaining the calibration permanent magnet magnetic chain; performing unit substitution to integrate a calibration data unit value table; the ratio of the bus voltage to the rotating speed and the calibration permanent magnet magnetic chain is input to the calibration data unit value, and the d-axis current unit data, the q-axis current unit data and the torque unit data are matched; obtaining the target bus voltage, the target rotating speed and the target rotor temperature, and obtaining the target permanent magnet magnetic chain; determining the correction input data, obtaining the target d-axis current unit data, the target q-axis current unit data and the target torque unit data; performing reverse unit substitution to obtain the target external characteristic data, and overcoming the problem that the permanent magnet synchronous motor external characteristic calibration data obtained by table lookup is inaccurate due to the difference between the actual rotor temperature and the calibration rotor temperature.

Description

Technical Field

[0001] This invention relates to the field of calibration data processing technology for permanent magnet synchronous motors, and in particular to a method, device, and medium for correcting external characteristic calibration data of permanent magnet synchronous motors. Background Technology

[0002] Permanent magnet synchronous motors are widely used in industrial control due to their high power density and high efficiency.

[0003] In the field of electric vehicles, permanent magnet synchronous motors are used as drive motors. To achieve precise control of output torque, the optimal parameters for motor control are typically calibrated offline and written into the program in a table. During actual operation, data such as motor torque and current at the current speed and voltage are obtained by looking up the table.

[0004] The flux linkage of permanent magnets is greatly affected by temperature, which in turn affects the external characteristic torque and current point of the motor. The offline calibration of the motor is generally carried out at a certain fixed rotor temperature. This means that when the rotor temperature in actual operation is different from the calibrated rotor temperature, the external characteristic torque and current point obtained by looking up the table will deviate from the actual value.

[0005] When a permanent magnet synchronous motor is in a voltage-limited weak magnetic field region and requires external characteristic torque, if the reference external characteristic torque obtained by looking up the table is greater than the actual output torque, and the reference current point in the table is also inaccurate, it will cause the software current controller to saturate, and in severe cases, it will lead to loss of control.

[0006] The theoretical calculation of the effect of changes in the flux linkage of permanent magnets on the external characteristic torque and current point is complex and inconvenient to calculate directly in the program. On the other hand, it is impractical to make calibration data of the external characteristics and current points at all rotor temperatures due to the large amount of data. Therefore, a simple and feasible method is needed to solve this problem. Summary of the Invention

[0007] In order to overcome the above-mentioned technical defects, the purpose of this invention is to provide a method, device and medium for correcting the external characteristic calibration data of permanent magnet synchronous motors, so as to overcome the problem that the external characteristic calibration data of permanent magnet synchronous motors obtained by looking up tables is inaccurate due to the difference between the rotor temperature and the calibrated rotor temperature during actual operation.

[0008] This invention discloses a method for correcting the external characteristic calibration data of a permanent magnet synchronous motor, comprising the following:

[0009] A mapping table is provided, wherein the mapping table includes multiple mapping relationships between rotor temperature and permanent magnet flux linkage;

[0010] Obtain the bus voltage and speed under the calibration conditions, and obtain the calibration permanent magnet flux from the mapping table based on the calibration rotor temperature under the calibration conditions;

[0011] The bus voltage and speed under the calibration conditions are input into a preset voltage limit circle function that includes d-axis current and q-axis current, and the calibration permanent magnet flux is used for per-unit replacement to generate the first function;

[0012] The torque is calculated using a preset torque function that includes d-axis current and q-axis current, and the per-unit replacement is performed using the square of the calibrated permanent magnet flux linkage to generate a second function;

[0013] Calculate the unique tangency point of the first function and the second function to obtain the per-unit data of d-axis current, q-axis current, and torque corresponding to the bus voltage and speed under the calibration conditions;

[0014] The bus voltage and the per-unit data of d-axis current, q-axis current, and torque corresponding to each speed under the calibration conditions are calculated and integrated into a calibration data per-unit value table; the calibration data per-unit value is input with the ratio of bus voltage to speed and calibration permanent magnet flux linkage, and matched with the corresponding d-axis current per-unit data, q-axis current per-unit data, and torque per-unit data;

[0015] Obtain the target bus voltage, target speed, and target rotor temperature under the target operating conditions, and obtain the target permanent magnet flux linkage from the mapping table based on the target rotor temperature;

[0016] The target bus voltage relative to the target rotational speed and the target permanent magnet flux ratio are determined as correction input data;

[0017] Obtain the target d-axis current per unit data, target q-axis current per unit data, and target torque per unit data that match the corrected input data from the calibration data per unit value table;

[0018] Based on the magnetic flux linkage of the target permanent magnet, the per-unit data of the d-axis current, q-axis current, and torque under the target operating condition are respectively replaced with reverse per-unit data to obtain the target external characteristic data.

[0019] Preferably, the step of performing per-unit replacement using the calibrated permanent magnet flux linkage to obtain the first function includes:

[0020] The first function is obtained by replacing the d-axis current, q-axis current, and target rotational speed in the voltage limit circle function with the ratios of d-axis current, q-axis current, bus voltage, and rotational speed to the ratios of the calibrated permanent magnet flux linkage, respectively.

[0021] The second function is obtained by per-unit substitution using the square of the calibrated permanent magnet flux linkage, including:

[0022] The torque in the torque function is replaced by the ratio of the torque to the square of the calibrated permanent magnet flux linkage to obtain the second function.

[0023] Preferably, the target permanent magnet flux linkage is used to correct the target bus voltage and target rotation speed to obtain corrected input data;

[0024] The step of performing reverse per-unit replacement on the d-axis current per-unit data and q-axis current per-unit data under the target operating condition based on the magnetic flux linkage of the target permanent magnet to obtain the target external characteristic data includes:

[0025] The target d-axis current and target q-axis current are obtained by multiplying the d-axis current per unit data and q-axis current per unit data under the target operating condition with the magnetic flux of the target permanent magnet, respectively.

[0026] The target torque is obtained by multiplying the per-unit torque value under the target operating condition by the square of the magnetic flux linkage of the target permanent magnet.

[0027] The target external characteristic data are obtained by combining the target d-axis current, target q-axis current, and target torque.

[0028] The present invention also provides a method for correcting the external characteristic calibration data of a permanent magnet synchronous motor, comprising the following:

[0029] A mapping table is provided, wherein the mapping table includes multiple mapping relationships between rotor temperature and permanent magnet flux linkage;

[0030] A parameter table is provided, wherein the parameter table takes the ratio of the bus voltage to each speed under the calibration condition as input and outputs the corresponding d-axis current, q-axis current and torque;

[0031] Obtain the calibrated rotor temperature under calibrated operating conditions, and obtain the calibrated permanent magnet flux linkage based on the mapping table;

[0032] Obtain the target rotor temperature under the target operating condition, and obtain the target permanent magnet flux linkage based on the mapping table;

[0033] The correction coefficient is calculated based on the ratio of the target permanent magnet flux linkage to the calibrated permanent magnet flux linkage;

[0034] Obtain the target bus voltage and target speed under the target operating conditions, and use the correction coefficient to correct the input based on the target bus voltage and target speed to obtain the first processed data;

[0035] Based on the first processed data, the matching d-axis current, q-axis current, and torque are obtained from the parameter table as the d-axis current, q-axis current, and torque to be corrected.

[0036] The correction coefficients are used to reverse the d-axis current, q-axis current, and torque to be corrected, thereby obtaining the target external characteristic data.

[0037] Preferably, the step of correcting the input based on the target bus voltage and target speed based on the correction coefficient to obtain the first processed data includes:

[0038] The first processed data is obtained by using the ratio of the target bus voltage to the product of the target rotational speed and the correction coefficient.

[0039] Preferably, the step of performing reverse correction on the d-axis current, q-axis current, and torque to be corrected based on the correction coefficient to obtain target external characteristic data includes:

[0040] The target d-axis current and target q-axis current are obtained by multiplying the d-axis current and q-axis current to be corrected with the correction coefficient;

[0041] The target torque is obtained by multiplying the torque to be corrected by the square of the correction coefficient.

[0042] The target external characteristic data are obtained by combining the target d-axis current, target q-axis current, and target torque.

[0043] The present invention also provides a computer device, the computer device comprising:

[0044] Memory, used to store executable program code; and

[0045] A processor for calling the executable program code in the memory, performing steps including any of the correction methods described above.

[0046] The present invention also provides a computer-readable storage medium having a computer program stored thereon.

[0047] When the computer program is executed by a processor, it implements the steps of any of the correction methods.

[0048] The present invention also provides a computer device, the computer device comprising:

[0049] Memory, used to store executable program code; and

[0050] A processor for calling the executable program code in the memory, performing steps including any of the correction methods described above.

[0051] The present invention also provides a computer-readable storage medium having a computer program stored thereon.

[0052] When the computer program is executed by a processor, it implements the steps of any of the correction methods.

[0053] Compared with existing technologies, the above technical solution has the following advantages:

[0054] According to the correction method of this invention, when the rotor temperature changes and causes the external characteristics of the motor to change, the accurate external characteristic data of the motor after the temperature change can be obtained simply by correcting the input and output of the calibration data lookup table without adding additional calibration data. This avoids the risk of runaway when the external characteristic torque is required and overcomes the problem that the calibration data of the permanent magnet synchronous motor obtained by looking up the table is inaccurate due to the difference between the rotor temperature and the calibration rotor temperature during actual operation. At the same time, this invention does not increase the calibration workload and software complexity, is simple to implement, and can be used for the precise control of permanent magnet synchronous motors. Attached Figure Description

[0055] Figure 1 This is a flowchart of an embodiment of the method for correcting the external characteristic calibration data of the permanent magnet synchronous motor described in this invention;

[0056] Figure 2 This is a schematic diagram of data processing in Embodiment 1 of the method for correcting the external characteristic calibration data of the permanent magnet synchronous motor described in this invention;

[0057] Figure 3 This is a flowchart of Embodiment 2 of the method for correcting the external characteristic calibration data of the permanent magnet synchronous motor according to the present invention;

[0058] Figure 4 This is a schematic diagram of data processing in Embodiment 2 of the method for correcting the external characteristic calibration data of the permanent magnet synchronous motor described in this invention;

[0059] Figure 5 This is a schematic diagram of a module in Embodiment 3 or Embodiment 5 of the present invention.

[0060] Figure label:

[0061] 31-Memory; 32-Processor. Detailed Implementation

[0062] The advantages of the present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments.

[0063] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0064] The terminology used in this disclosure is for descriptive purposes only and is not intended to be limiting of the disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0065] It should be understood that although the terms first, second, third, etc., may be used in this disclosure to describe various information, such information should not be limited to these terms. These terms are used only to distinguish information of the same type from one another. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0066] In the description of this invention, it should be understood that the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specified orientation, or be constructed and operated in a specified orientation. Therefore, they should not be construed as limitations on this invention.

[0067] In the description of this invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0068] Example 1: This example discloses a method for correcting the external characteristic calibration data of a permanent magnet synchronous motor. (See attached document.) Figure 1 and Figure 2 This includes the following steps:

[0069] A mapping table is provided, wherein the mapping table includes multiple rotor temperatures (t) and permanent magnet flux linkages. The mapping relationship; let the motor bus voltage (U) under each calibration condition be... lim The target current includes the motor's rotational speed (ω), d-axis current (id), and q-axis current (iq). Specifically, the target bus voltage and target rotational speed under the target operating conditions are expressed as U... lim_t ω t .

[0070] S110: Obtain the bus voltage and speed under the calibration conditions, and obtain the calibration permanent magnet flux from the mapping table according to the calibration rotor temperature under the calibration conditions;

[0071] Specifically, in this embodiment, the main issue is that the rotor temperature during actual operation differs from the calibrated rotor temperature, leading to a significant temperature-dependent effect on the permanent magnet flux linkage. This, in turn, affects the motor's external characteristic torque and current point, thus requiring correction. The calibrated permanent magnet flux linkage is determined from the mapping table. And subsequently found the corresponding permanent magnet flux linkage under the target working condition. Data correction can be performed using the magnetic flux of the permanent magnet.

[0072] S120: Input the bus voltage and speed under the calibration conditions into a preset voltage limit circle function that includes d-axis current and q-axis current, and use the calibration permanent magnet flux linkage to perform per-unit replacement to generate the first function;

[0073] Specifically, ignoring stator voltage drop and inductance changes, the preset voltage limit circle function including d-axis current and q-axis current is:

[0074]

[0075] Where Ld and Lq are the d-axis inductance and q-axis inductance, and Id and Iq are the d-axis current and q-axis current, respectively. For permanent magnet flux linkage, U lim ω represents the bus voltage and ω represents the rotational speed.

[0076] Specifically, the first function is obtained by per-unit replacement using the calibrated permanent magnet flux linkage, including: replacing the d-axis current, q-axis current, and bus voltage in the voltage limit circle function with the ratios of the d-axis current, q-axis current, bus voltage, and rotational speed to the ratios of the calibrated permanent magnet flux linkage, respectively, to obtain the first function;

[0077] Specifically, with Based on this, we perform per-unit substitution on both sides of the function (1) above to obtain:

[0078]

[0079] Then, based on the above equation (2), iq is used * replace id * replace for get:

[0080] That is, the first function.

[0081] S130: The torque is calculated using a preset torque function that includes d-axis current and q-axis current, and the per-unit replacement is performed using the square of the calibrated permanent magnet flux linkage to generate the second function;

[0082] Specifically, the preset torque formula, which includes d-axis current and q-axis current, is as follows:

[0083]

[0084] Where Trq is the torque, Pn is the number of pole pairs of the motor, Ld and Lq are the d-axis inductance and q-axis inductance, and Id and Iq are the d-axis current and q-axis current.

[0085] Specifically, the second function is obtained by replacing the torque with the square of the target permanent magnet flux linkage per unit value. This includes replacing the torque, d-axis current, and q-axis current in the preset function with the ratios of the torque, d-axis current, and q-axis current in the data to be corrected to the square of the calibrated permanent magnet flux linkage, respectively, to obtain the second function.

[0086] Specifically, to divide by Replace the torque with a per-unit rating:

[0087]

[0088] Then, based on the above equation (5), Trq is used. * replace id * replace replace get:

[0089] Trq * =1.5*Pn*(1+(Ld-Lq)*id) * )*iq * (6), which is the second function.

[0090] S140: Calculate the unique tangent point of the first function and the second function to obtain the per-unit data of d-axis current, q-axis current, and torque corresponding to the bus voltage and speed under the calibration conditions;

[0091] In this embodiment, based on the above equations (3) and (6), a system of equations is formed, and the unique definite solution (id) when they are tangent is calculated. * iq * This is the unique tangent point of the first and second functions mentioned above (i.e., the characteristic point outside the weak magnetic region limited by voltage), from which id can be obtained. * iq * Trq *This serves as the per-unit data for d-axis current, q-axis current, and torque under calibrated operating conditions.

[0092] S150: Calculate the bus voltage and the per-unit data of d-axis current, q-axis current, and torque corresponding to each speed under the calibration conditions, and integrate them into a calibration data per-unit value table; the calibration data per-unit value is input with the ratio of bus voltage to speed and calibration permanent magnet flux linkage, and matches the corresponding per-unit data of d-axis current, q-axis current, and torque.

[0093] Specifically, steps S110-140 above are all used to calibrate the per-unit value table of data (wherein, Figure 2 fixed The area containing the per-unit values ​​of external characteristics is the calibration data per-unit value table generated in this step, which realizes the per-unit scaling of the calibration data, and the calibration data will be fixed. Fixed U lim ω is determined at different rotational speeds. As the input axis, the corresponding (id) * iq * ), Trq * As the output shaft, it is used in subsequent steps to determine the target d-axis current per unit data, target q-axis current per unit data, and target torque per unit data by referring to tables based on the target bus voltage, target speed, and target rotor temperature under the target operating conditions.

[0094] S160: Obtain the target bus voltage, target speed, and target rotor temperature under the target operating condition, and obtain the target permanent magnet flux linkage from the mapping table based on the target rotor temperature; determine the ratio of the target bus voltage to the target speed and the target permanent magnet flux linkage as correction input data; obtain the target d-axis current per unit data, target q-axis current per unit data, and target torque per unit data that match the correction input data from the calibration data per unit value table;

[0095] In this embodiment, during actual operation, the target bus voltage and target speed under the target operating conditions are used as inputs. The per-unit data for d-axis current, q-axis current, and torque can be output according to the calibration data per-unit value table. That is, by inputting the target bus voltage, target speed, and target permanent magnet flux linkage, the per-unit data for d-axis current, q-axis current, and torque are directly obtained by looking up the table (stored table), and then reverse per-unit calibration is performed to obtain the target external characteristic data. In actual use, based on the current changes in rotor temperature... The current bus voltage is calculated to be U lim_T The current motor speed ω is calculated, and the final calculation is obtained by looking up the table (mapping table) input. The result of looking up the table (the calibration data per-unit value table) is the per-unit value (id) of the external characteristic current under the current rotor temperature, bus voltage, and speed. * iq * The per-unit value of the external characteristic torque is Trq. * .

[0096] S170: Based on the magnetic flux linkage of the target permanent magnet, the per-unit data of the d-axis current, the per-unit data of the q-axis current, and the per-unit data of the torque under the target operating condition are replaced with reverse per-unit data to obtain the target external characteristic data.

[0097] In this embodiment, based on the above equations (2) and (6), it can be seen that the per-unit values ​​of the d-axis current, q-axis current, and torque are respectively calculated by dividing the d-axis current and q-axis current by the permanent magnet flux linkage under the calibration condition. Torque divided by the square of the permanent magnet flux under the target operating condition Therefore, after obtaining the per-unit values ​​under the target operating conditions, it is necessary to reconstruct them to obtain the d-axis current, q-axis current, and torque under the target operating conditions (i.e., those conforming to the current rotor temperature).

[0098] Specifically, the step of performing reverse per-unit replacement on the d-axis current per-unit data and q-axis current per-unit data under the target operating condition based on the magnetic flux linkage of the target permanent magnet to obtain the target external characteristic data includes:

[0099] S171: Based on the product of the per-unit data of the d-axis current and the per-unit data of the q-axis current under the target operating condition and the magnetic flux of the target permanent magnet, the target d-axis current (Id) and the target q-axis current (Iq) are obtained respectively.

[0100] In this embodiment,

[0101] S172: The target torque is obtained by multiplying the per-unit torque value under the target operating condition by the square of the magnetic flux linkage of the target permanent magnet;

[0102] In this embodiment, Trp t The target torque is the torque under the target operating conditions.

[0103] S173: Combine the target d-axis current, target q-axis current and target torque to obtain the target external characteristic data.

[0104] Therefore, based on the above steps S161 and S162, the target d-axis current, target q-axis current, and target torque can be output, which are all currents and torques under the target operating conditions, i.e., matched with the actual rotor temperature. Considering that the permanent magnet flux linkage is greatly affected by temperature, which in turn affects the external characteristic torque and current of the motor, the calibration data of the motor at a certain fixed rotor temperature is corrected by using the permanent magnet flux linkage corresponding to the actual rotor temperature to overcome the problem of inaccurate external characteristic torque and current obtained by looking up the table.

[0105] In this embodiment, when the rotor temperature changes, causing a change in the motor's external characteristics, without adding additional calibration data, only the input and output of the calibration data lookup table are used (during the calibration process...). The bus voltage Ulim and ω at different speeds are determined. As the input axis, the corresponding (id) * iq * ), Trq * As the output shaft, in actual operation, the current temperature varies with the rotor temperature. The current bus voltage is calculated to be U lim_T The current motor speed ω is calculated, and the final calculation is obtained by looking up the table input. By making corrections, accurate motor external characteristic data corresponding to temperature changes can be obtained, avoiding the risk of runaway when demanding external characteristic torque. This invention does not increase calibration workload or software complexity, is simple to implement, and can be used for precise control of permanent magnet synchronous motors.

[0106] Example 2: This example also provides a method for correcting the external characteristic calibration data of a permanent magnet synchronous motor. (See attached document.) Figure 3 and Figure 4 This includes the following steps:

[0107] A mapping table is provided, wherein the mapping table includes multiple mapping relationships between rotor temperature and permanent magnet flux linkage; it should be noted that the mapping table has the same function and form as in Embodiment 1, and will not be described again here. It should also be noted that the symbol representation in this embodiment is consistent with that in Embodiment 1.

[0108] A parameter table is provided, wherein the parameter table takes the ratio of the bus voltage to each speed under the calibrated operating condition as input, and outputs the corresponding d-axis current, q-axis current, and torque (e.g., ...). Figure 4 Central fixation The area where the physical values ​​of the external characteristic calibration data are located is the parameter table); specifically, based on the ratio of bus voltage to rotational speed, the calibrated permanent magnet flux can be solved by combining formulas (1) and (4) in Example 1 to obtain the d-axis current, q-axis current and torque, or the d-axis current, q-axis current and torque can be directly collected and stored after processing under calibration conditions.

[0109] S210: Obtain the calibrated rotor temperature under calibrated operating conditions, and obtain the calibrated permanent magnet flux linkage based on the mapping table;

[0110] Specifically, the offline calibration of the motor is generally carried out at a certain fixed rotor temperature. Therefore, obtaining this fixed rotor temperature is the calibration rotor temperature, and the calibration permanent magnet flux can be obtained.

[0111] S220: Obtain the target rotor temperature under the target operating condition, and obtain the target permanent magnet flux linkage based on the mapping table;

[0112] Specifically, the main issue is that the rotor temperature during actual operation differs from the calibrated rotor temperature, leading to a significant temperature-dependent effect on the permanent magnet flux linkage. This, in turn, affects the motor's external characteristic torque and current point, thus requiring correction. Therefore, the target rotor temperature (t) is determined from the mapping table, and the corresponding permanent magnet flux linkage under the target operating condition is found. Data correction can be performed using the magnetic flux of the permanent magnet.

[0113] S230: Calculate the correction coefficient based on the ratio of the target permanent magnet flux linkage to the calibrated permanent magnet flux linkage;

[0114] In this embodiment, it is important to emphasize that, unlike in Embodiment 1, the correction coefficient is calculated using the ratio of the target permanent magnet flux linkage to the calibrated permanent magnet flux linkage to directly correct the d-axis current, q-axis current, and torque. Considering that the method of correcting the d-axis current, q-axis current, and torque using the target permanent magnet flux linkage and its square is not readily apparent in actual operation, the aforementioned correction coefficient is used. The input axis is multiplied by this correction coefficient, and then a table is looked up. Multiplying by the correction coefficient yields the corrected d-axis current and q-axis current (id, iq), and multiplying by the square of the correction coefficient yields the corrected torque Trq, thus achieving the correction effect. The operation is simple, convenient, and quick.

[0115] S240: Obtain the target bus voltage and target speed under the target operating condition, and use the correction coefficient to correct the input based on the target bus voltage and target speed to obtain the first processed data;

[0116] Specifically, the step of correcting the input based on the target bus voltage and target speed based on the correction coefficient to obtain the first processed data includes: obtaining the first processed data by using the ratio of the target bus voltage to the product of the target speed and the correction coefficient.

[0117] Specifically, the ratio of the target bus voltage to the product of the target rotational speed and the correction coefficient (i.e., the first processed data) can be expressed as follows: Based on this, the d-axis current, q-axis current, and torque can be matched in the following steps.

[0118] S250: Obtain the matching d-axis current, q-axis current and torque from the parameter table based on the first processing data, as the d-axis current, q-axis current and torque to be corrected;

[0119] It should be noted that the difference between this embodiment and Embodiment 1 is that the parameter table in this embodiment is the physical value of the calibration external characteristic data, which is corrected by the above correction coefficient, while in Embodiment 1 it is based on the per-unit value of the calibration external characteristic data. The two achieve the same effect, but this embodiment is more convenient to clearly demonstrate the actual operation.

[0120] S260: The correction coefficient is used to reverse the d-axis current, q-axis current and torque to be corrected, and the target external characteristic data is obtained;

[0121] Specifically, the step of performing reverse correction on the d-axis current, q-axis current, and torque to be corrected based on the correction coefficient to obtain target external characteristic data includes:

[0122] S261: Obtain the target d-axis current and target q-axis current by multiplying the d-axis current and q-axis current to be corrected with the correction coefficient;

[0123] Specifically, the table lookup result (id, iq) is multiplied by the correction coefficient to obtain the corrected (id, iq), which is (Id, Iq), i.e., Id = id * A, Iq = iq * A, where A is the correction coefficient.

[0124] S262: Obtain the target torque by multiplying the torque to be corrected by the square of the correction coefficient;

[0125] Specifically, the table lookup result Trq is multiplied by the square of the coefficient to obtain the corrected Trq, Trp. t =Trq*A 2 Trp t Let A be the target torque and A be the correction factor.

[0126] S263: Combine the target d-axis current, target q-axis current and target torque to obtain the target external characteristic data.

[0127] This embodiment can obtain the standardized physical values ​​(i.e., without performing the standardization described in Embodiment 1 above, directly obtaining the d-axis current, q-axis current, and torque under calibration conditions) through modification, specifically as follows: the calibration data lookup table values ​​do not use fixed... Instead of using per-unit notation, the physical values ​​(id, iq) and Trq are used directly, representing the variation with rotor temperature. Fixed corresponding to calibration data Divide to obtain the correction coefficient. Multiply the input axis of the lookup table by the correction coefficient, and then look up the table again. Multiply the lookup result (id, iq) by the correction coefficient to obtain the corrected (id, iq). Multiply the lookup result Trq by the square of the correction coefficient to obtain the corrected Trq. When the rotor temperature changes, causing changes in the motor's external characteristics, without adding additional calibration data, accurate motor external characteristic data corresponding to the temperature change can be obtained simply by correcting the input and output axes of the calibration data lookup table. This overcomes the problem of inaccurate calibration data of permanent magnet synchronous motor external characteristics obtained by looking up the table due to the difference between the rotor temperature during actual operation and the calibration rotor temperature.

[0128] Example 3: To achieve the above objectives, the present invention also provides a computer device, comprising: a memory for storing executable program code; and a processor for calling the executable program code in the memory, the execution steps including any of the correction methods described above. The computer device may be a smartphone, tablet computer, laptop computer, desktop computer, rack server, blade server, tower server, or cabinet server (including standalone servers or server clusters composed of multiple servers), etc., that executes programs. The computer device in this embodiment includes, but is not limited to: a memory 31 and a processor 32 that can be interconnected via a system bus, such as... Figure 5 As shown. It should be noted that, Figure 5 Only computer devices with components are shown; however, it should be understood that it is not required to implement all of the components shown, and more or fewer components may be implemented instead.

[0129] In this embodiment, the memory 31 (i.e., the readable storage medium) includes flash memory, hard disk, etc. In some embodiments, the memory 31 may be an internal storage unit of a computer device, such as the hard disk or memory of the computer device. In other embodiments, the memory 31 may also be an external storage device of the computer device, such as a plug-in hard disk or a smart media card (SMC) equipped on the computer device. In this embodiment, the memory 31 is typically used to store the operating system and various application software installed on the computer device, such as the program code of the correction method in Embodiment 1. In addition, the memory 31 may also be used to temporarily store various types of data that have been output or will be output.

[0130] In some embodiments, processor 32 may be a central processing unit (CPU), controller, microcontroller, microprocessor, or other data processing chip. This processor 32 is typically used to control the overall operation of a computer device. In this embodiment, processor 32 is used to run program code stored in memory 31 or process data, for example, to run the steps of the correction method to implement the correction method of Embodiment 1.

[0131] Example 4: To achieve the above objectives, the present invention also provides a computer-readable storage system, which includes multiple storage media, such as flash memory, hard disk, multimedia card, card-type memory (e.g., SD or DX memory), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM), magnetic memory, disk, optical disk, server, App application store, etc., on which computer programs are stored. When the program is executed by processor 32, it implements the corresponding function. In this embodiment, the computer-readable storage medium is used to store working parameters, and when executed by processor 32, it implements the modified method of Example 1.

[0132] Example 5: To achieve the above objectives, the present invention also provides a computer device, comprising: a memory for storing executable program code; and a processor for calling the executable program code in the memory, the execution steps including any of the correction methods described above. The computer device may be a smartphone, tablet computer, laptop computer, desktop computer, rack server, blade server, tower server, or cabinet server (including independent servers or server clusters composed of multiple servers), etc., that executes programs. The computer device in this embodiment includes, but is not limited to: a memory 31 and a processor 32 that can be interconnected via a system bus, such as... Figure 5 As shown. It should be noted that, Figure 5 Only computer devices with components are shown; however, it should be understood that it is not required to implement all of the components shown, and more or fewer components may be implemented instead.

[0133] In this embodiment, the memory 31 (i.e., the readable storage medium) includes flash memory, hard disk, etc. In some embodiments, the memory 31 may be an internal storage unit of a computer device, such as the hard disk or memory of the computer device. In other embodiments, the memory 31 may also be an external storage device of the computer device, such as a plug-in hard disk or a smart media card (SMC) equipped on the computer device. In this embodiment, the memory 31 is typically used to store the operating system and various application software installed on the computer device, such as the program code of the correction method in Embodiment 2. In addition, the memory 31 may also be used to temporarily store various types of data that have been output or will be output.

[0134] In some embodiments, processor 32 may be a central processing unit (CPU), controller, microcontroller, microprocessor, or other data processing chip. This processor 32 is typically used to control the overall operation of a computer device. In this embodiment, processor 32 is used to run program code stored in memory 31 or process data, for example, to run the steps of the correction method of Embodiment 2 to implement the correction method of Embodiment 2.

[0135] Example 6: To achieve the above objectives, the present invention also provides a computer-readable storage system, which includes multiple storage media, such as flash memory, hard disk, multimedia card, card-type memory (e.g., SD or DX memory), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM), magnetic memory, disk, optical disk, server, App application store, etc., on which computer programs are stored. When the program is executed by processor 32, it implements the corresponding function. In this embodiment, the computer-readable storage medium is used to store working parameters, and when executed by processor 32, it implements the modified method of Example 2.

[0136] In the following description, suffixes such as "module," "part," or "unit" used to denote elements are used only for the convenience of the description of the invention and have no inherent meaning. Therefore, "module" and "part" can be used interchangeably.

[0137] It should be noted that the embodiments of the present invention have better implementability and are not intended to limit the present invention in any way. Any person skilled in the art may use the above-disclosed technical content to change or modify it into equivalent effective embodiments. However, any modifications or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A method for correcting external characteristic calibration data of a permanent magnet synchronous motor, characterized in that, Including the following: A mapping table is provided, wherein the mapping table includes multiple mapping relationships between rotor temperature and permanent magnet flux linkage; Obtain the bus voltage and speed under the calibration conditions, and obtain the calibration permanent magnet flux from the mapping table based on the calibration rotor temperature under the calibration conditions; The bus voltage and speed under the calibration conditions are input into a preset voltage limit circle function that includes d-axis current and q-axis current, and the calibration permanent magnet flux is used for per-unit replacement to generate the first function; The torque is calculated using a preset torque function that includes d-axis current and q-axis current, and the per-unit replacement is performed using the square of the calibrated permanent magnet flux linkage to generate a second function; Calculate the unique tangency point of the first function and the second function to obtain the per-unit data of d-axis current, q-axis current, and torque corresponding to the bus voltage and speed under the calibration conditions; Calculate the per-unit data of d-axis current, q-axis current, and torque corresponding to each bus voltage and speed under the calibration conditions, and integrate them into a calibration data per-unit value table; the calibration data per-unit value table takes the ratio of bus voltage to speed and calibration permanent magnet flux linkage as input, and matches the corresponding per-unit data of d-axis current, q-axis current, and torque. Obtain the target bus voltage, target speed, and target rotor temperature under the target operating conditions, and obtain the target permanent magnet flux linkage from the mapping table based on the target rotor temperature; The target bus voltage relative to the target rotational speed and the target permanent magnet flux ratio are determined as correction input data; Obtain the target d-axis current per unit data, target q-axis current per unit data, and target torque per unit data that match the corrected input data from the calibration data per unit value table; Based on the magnetic flux linkage of the target permanent magnet, the per-unit data of the d-axis current, q-axis current, and torque under the target operating condition are respectively replaced with reverse per-unit data to obtain the target external characteristic data.

2. The correction method according to claim 1, characterized in that: The step of performing per-unit replacement using the calibrated permanent magnet flux linkage to obtain the first function includes: The first function is obtained by replacing the d-axis current, q-axis current, and target rotational speed in the voltage limit circle function with the ratios of d-axis current, q-axis current, bus voltage, and rotational speed to the ratios of the calibrated permanent magnet flux linkage, respectively. The second function is obtained by per-unit substitution using the square of the calibrated permanent magnet flux linkage, including: The torque in the torque function is replaced by the ratio of the torque to the square of the calibrated permanent magnet flux linkage to obtain the second function.

3. The correction method according to claim 1, characterized in that, The target permanent magnet flux linkage is used to correct the target bus voltage and target rotation speed to obtain correction input data; The step of performing reverse per-unit replacement on the d-axis current per-unit data and q-axis current per-unit data under the target operating condition based on the magnetic flux linkage of the target permanent magnet to obtain the target external characteristic data includes: The target d-axis current and target q-axis current are obtained by multiplying the d-axis current per unit data and q-axis current per unit data under the target operating condition with the magnetic flux of the target permanent magnet, respectively. The target torque is obtained by multiplying the per-unit torque value under the target operating condition by the square of the magnetic flux linkage of the target permanent magnet. The target external characteristic data are obtained by combining the target d-axis current, target q-axis current, and target torque.

4. A method for correcting external characteristic calibration data of a permanent magnet synchronous motor, characterized in that, Including the following: A mapping table is provided, wherein the mapping table includes multiple mapping relationships between rotor temperature and permanent magnet flux linkage; A parameter table is provided, wherein the parameter table takes the ratio of the bus voltage to each speed under the calibration condition as input and outputs the corresponding d-axis current, q-axis current and torque; Obtain the calibrated rotor temperature under calibrated operating conditions, and obtain the calibrated permanent magnet flux linkage based on the mapping table; Obtain the target rotor temperature under the target operating condition, and obtain the target permanent magnet flux linkage based on the mapping table; The correction coefficient is calculated based on the ratio of the target permanent magnet flux linkage to the calibrated permanent magnet flux linkage; Obtain the target bus voltage and target speed under the target operating conditions, and use the correction coefficient to correct the input based on the target bus voltage and target speed to obtain the first processed data; Based on the first processed data, the matching d-axis current, q-axis current, and torque are obtained from the parameter table as the d-axis current, q-axis current, and torque to be corrected. The correction coefficients are used to reverse the d-axis current, q-axis current, and torque to be corrected, thereby obtaining the target external characteristic data.

5. The correction method according to claim 4, characterized in that, The step of correcting the input based on the target bus voltage and target speed according to the correction coefficient to obtain the first processed data includes: The first processed data is obtained by using the ratio of the target bus voltage to the product of the target rotational speed and the correction coefficient.

6. The correction method according to claim 4, characterized in that, Based on the correction coefficient, the d-axis current, q-axis current, and torque to be corrected are reversed to obtain target external characteristic data, including: The target d-axis current and target q-axis current are obtained by multiplying the d-axis current and q-axis current to be corrected with the correction coefficient; The target torque is obtained by multiplying the torque to be corrected by the square of the correction coefficient. The target external characteristic data are obtained by combining the target d-axis current, target q-axis current, and target torque.

7. A computer device, characterized in that: The computer device includes: Memory, used to store executable program code; and A processor for calling the executable program code in the memory, performing steps including the correction method as described in any one of claims 1-3.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, it implements the steps of the correction method according to any one of claims 1-3.

9. A computer device, characterized in that: The computer device includes: Memory, used to store executable program code; and A processor for calling the executable program code in the memory, performing steps including the correction method as described in any one of claims 4-6.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, it implements the steps of the correction method according to any one of claims 4-6.

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