Current calibration method and device based on virtual calibration technology, and motor

Abstract

The invention discloses a current calibration method and device based on a virtual calibration technology, and a motor, and relates to the technical field of motors. The method comprises the following steps: acquiring a first set of direct-axis current and quadrature-axis current combinations under different voltages, different rotating speeds and different stator currents based on a virtual calibration platform; acquiring a second set of direct-axis current and quadrature-axis current combinations under different voltages, different rotating speeds and different stator currents based on the calibration rack and the first set; a target set of direct-axis current and quadrature-axis current combinations is determined based on the first set and the second set. According to the calibration method, a round of pre-calibration is carried out on the direct-axis current and quadrature-axis current combination under different voltages, different rotating speeds and different stator currents based on the virtual calibration platform, and then secondary calibration verification is carried out on the motor calibration rack so as to determine the target set of the direct-axis current and quadrature-axis current combination. Therefore, the calibration efficiency and the calibration precision can be improved, and the motor calibration time is shortened.

Description

Technical Field

[0001] The present application relates to the field of motor technology, and in particular to a current calibration method based on virtual calibration technology, a current calibration method based on virtual calibration technology, and a motor. Background Art

[0002] In the related technology, manual calibration is usually adopted, that is, under target operating conditions of different target torques and speeds, the direct-axis current and quadrature-axis current are manually adjusted to obtain the optimal torque, minimum current, and maximum system efficiency parameters under the target operating point. This method is prone to reading errors during manual processing, affecting the calibration accuracy, and also consumes a lot of time and labor costs. Summary of the invention

[0003] The present application aims to solve one of the technical problems in the related art at least to a certain extent. To this end, the first purpose of the present application is to propose a current calibration method based on virtual calibration technology, the method comprising: obtaining a first set of direct-axis current and quadrature-axis current combinations under different voltages, different speeds, and different stator currents based on a virtual calibration platform; obtaining a second set of direct-axis current and quadrature-axis current combinations under different voltages, different speeds, and different stator currents based on a calibration bench and the first set; determining a target set of direct-axis current and quadrature-axis current combinations based on the first set and the second set. The calibration method of the present application performs a round of pre-calibration on the direct-axis current and quadrature-axis current combinations under different voltages, different speeds, and different stator currents based on a virtual calibration platform, and then performs a secondary calibration verification on the direct-axis current and quadrature-axis current combinations under different voltages, different speeds, and different stator currents on a motor calibration bench to determine the target set of direct-axis current and quadrature-axis current combinations. In this way, the calibration efficiency and calibration accuracy can be improved, and the motor calibration time can be shortened.

[0004] The second objective of the present application is to provide a current calibration device based on virtual calibration technology.

[0005] The third object of the present application is to provide a motor.

[0006] To achieve the above-mentioned objectives, the first aspect of the present application proposes a current calibration method based on virtual calibration technology, the method comprising: obtaining a first set of direct-axis current and quadrature-axis current combinations under different voltages, different speeds, and different stator currents based on a virtual calibration platform; obtaining a second set of direct-axis current and quadrature-axis current combinations under different voltages, different speeds, and different stator currents based on the calibration bench and the first set; and determining a target set of direct-axis current and quadrature-axis current combinations based on the first set and the second set.

[0007] According to one embodiment of the present application, a first set of direct-axis current and quadrature-axis current combinations under different voltages, different speeds, and different stator currents is obtained based on a virtual calibration platform, including: when the speed is less than or equal to a preset inflection point speed, obtaining the current motor operating condition; determining the direct-axis current and quadrature-axis current combinations and the motor torque under different current angles according to the current motor operating condition and the current stator current; determining the first target direct-axis current and quadrature-axis current combination under the current voltage, the current speed, and the current stator current according to the maximum value of the motor torque; and determining the first set according to the first target direct-axis current and quadrature-axis current combination under different voltages, different speeds, and different stator currents.

[0008] According to one embodiment of the present application, a first set of direct-axis current and quadrature-axis current combinations under different voltages, different speeds, and different stator currents is obtained based on a virtual calibration platform, including: when the speed is greater than a preset inflection point speed, the voltage utilization rate is obtained; when the voltage utilization rate is less than the required voltage utilization rate, the direct-axis current and quadrature-axis current combinations under different current angles and the motor torque are determined according to the current motor operating condition and the current stator current, and the first target direct-axis current and quadrature-axis current combination under the current voltage, the current speed, and the current stator current is determined according to the maximum value of the motor torque; when the voltage utilization rate is greater than or equal to the required voltage utilization rate, the step size of the current angle is reduced, and the direct-axis current and quadrature-axis current combinations under different current angles and the motor torque are determined according to the current motor operating condition and the current stator current, and the first target direct-axis current and quadrature-axis current combination under the current voltage, the current speed, and the current stator current is determined according to the maximum value of the motor torque; the first set is determined according to the first target direct-axis current and quadrature-axis current combination under different voltages, different speeds, and different stator currents. According to one embodiment of the present application, direct-axis current and quadrature-axis current combinations under different current angles are determined according to the current motor operating condition and the current stator current, including: when the current motor operating condition is an electric operating condition, controlling the current angle to increase from a first preset angle to a second preset angle according to a first current angle step to obtain multiple direct-axis current and quadrature-axis current combinations; when the current motor operating condition is a power generation condition, controlling the current angle to decrease from a third preset angle to a second preset angle according to a second current angle step to obtain multiple direct-axis current and quadrature-axis current combinations, wherein the current angle is the angle between the stator current and the quadrature-axis current.

[0009] According to one embodiment of the present application, different voltages include the rated voltage, maximum allowable voltage and minimum allowable voltage of the motor, the stator current increases according to a first current step, and the speed increases according to a first speed step until a preset maximum speed is reached; at the current voltage and the current speed, if the speed is greater than the preset inflection point speed and the motor power corresponding to the current stator current is greater than the preset maximum motor power or the motor power change rate is less than the preset change rate, the speed is increased according to the first speed step; at the current voltage and the current speed, if the speed is less than or equal to the preset inflection point speed and the current stator current is greater than the preset maximum current or the motor power corresponding to the current stator current is greater than the preset maximum motor power, the speed is increased according to the first speed step.

[0010] According to one embodiment of the present application, in a second set obtained based on a calibration test bench, an increase step size of the stator current is greater than an increase step size of the stator current in a first set obtained based on a virtual test bench, and in a second set obtained based on a calibration test bench, an increase step size of the speed is greater than an increase step size of the speed in the first set obtained based on a virtual test bench. A second set of direct-axis current and quadrature-axis current combinations under different voltages, different speeds, and different stator currents is obtained based on the calibration test bench and the first set, including: when the speed is less than or equal to a preset inflection point speed, determining an initial value of the current angle according to a current stator current and a target direct-axis current and quadrature-axis current combination corresponding to the current stator current in the first set; determining a direct-axis current and quadrature-axis current combination and a motor torque under different current angles according to the initial value of the current angle; determining a second target direct-axis current and quadrature-axis current combination under the current voltage, the current speed, and the current stator current according to the maximum value of the motor torque; and determining a second set according to a second target direct-axis current and quadrature-axis current combination under different voltages, different speeds, and different stator currents.

[0011] According to one embodiment of the present application, a second set of direct-axis current and quadrature-axis current combinations under different voltages, different speeds, and different stator currents is obtained based on a calibration test bench and a first set, including: when the speed is greater than a preset inflection point speed, obtaining the voltage utilization; when the voltage utilization is less than the required voltage utilization, determining the direct-axis current and quadrature-axis current combinations under different current angles according to the speed and different stator currents; when the voltage utilization is greater than or equal to the required voltage utilization, reducing the step size of the current angle, and determining the direct-axis current and quadrature-axis current combinations under different current angles and the motor torque according to the current stator current, and determining the second target direct-axis current and quadrature-axis current combinations under the current voltage, current speed, and current stator current according to the maximum value of the motor torque; determining the second set according to the second target direct-axis current and quadrature-axis current combinations under different voltages, different speeds, and different stator currents.

[0012] According to one embodiment of the present application, the direct-axis current and quadrature-axis current combinations and the motor torque at different current angles are determined based on the initial value of the current angle, including: controlling the initial value of the current angle to increase to a third preset angle according to a third current angle step to obtain multiple direct-axis current and quadrature-axis current combinations and the motor torque; controlling the initial value of the current angle to decrease to a fourth preset angle according to the third current angle step to obtain multiple direct-axis current and quadrature-axis current combinations and the motor torque.

[0013] To achieve the above-mentioned objectives, the second aspect of the present application proposes a current calibration device based on virtual calibration technology, the device comprising: a first acquisition module, used to acquire a first set of direct-axis current and quadrature-axis current combinations under different voltages, different speeds, and different stator currents based on a virtual calibration platform; a second acquisition module, used to acquire a second set of direct-axis current and quadrature-axis current combinations under different voltages, different speeds, and different stator currents based on a calibration bench and the first set; and a determination module, used to determine a target set of direct-axis current and quadrature-axis current combinations based on the first set and the second set.

[0014] To achieve the above-mentioned objectives, the third aspect embodiment of the present application proposes a motor, including a memory, a processor, and a current calibration program based on virtual calibration technology stored in the memory and executable on the processor. When the processor executes the current calibration program based on virtual calibration technology, the aforementioned current calibration method based on virtual calibration technology is implemented.

[0015] According to the current calibration method, device and motor based on virtual calibration technology of the embodiment of the present application, a first set of direct-axis current and quadrature-axis current combinations under different voltages, different speeds and different stator currents is obtained based on the virtual calibration platform; a second set of direct-axis current and quadrature-axis current combinations under different voltages, different speeds and different stator currents is obtained based on the calibration bench and the first set; a target set of direct-axis current and quadrature-axis current combinations is determined based on the first set and the second set. The calibration method of the present application performs a round of pre-calibration on the direct-axis current and quadrature-axis current combinations under different voltages, different speeds and different stator currents based on the virtual calibration platform, and then performs a secondary calibration verification on the direct-axis current and quadrature-axis current combinations under different voltages, different speeds and different stator currents on the motor calibration bench to determine the target set of direct-axis current and quadrature-axis current combinations. In this way, the calibration efficiency and calibration accuracy can be improved, and the motor calibration time can be shortened. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a flow chart of a current calibration method based on virtual calibration technology according to some embodiments of the present application;

[0017] Figure 2 is a schematic diagram of a current angle according to some embodiments of the present application;

[0018] Figure 3 It is a structural schematic diagram of a current calibration device based on virtual calibration technology according to some embodiments of the present application;

[0019] Figure 4 is a block diagram of a motor according to some embodiments of the present application. DETAILED DESCRIPTION

[0020] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0021] The current calibration method, device and motor based on virtual calibration technology according to the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0022] Figure 1 Flow chart of a current calibration method based on virtual calibration technology according to some embodiments of the present application. Figure 1 The current calibration method based on the virtual calibration technology in the embodiment of the present application may include the following steps:

[0023] S110, acquiring a first set of combinations of direct-axis current and quadrature-axis current under different voltages, different speeds, and different stator currents based on the virtual calibration platform.

[0024] Specifically, the motor physical characteristic parameters, such as inductance, flux, stator resistance and temperature relationship, are extracted through MAXWEL and DOE sequence setting methods, and a matlab / simulink motor model is generated and obtained after training with a large amount of measured data in the early stage to cover the motor model that characterizes the actual motor characteristics. After the matlab / simulink virtual calibration platform including the dynamometer model, which can directly measure torque, speed and output power (different speeds can be set), the target inverter module model and the target motor model are established, the target electric drive system calibration software is loaded, and the current pre-calibration based on the virtual calibration platform can be performed to obtain multiple direct-axis currents and quadrature-axis currents under different voltages, different speeds, and different stator currents, and the non-smooth points need to be corrected to determine the first set.

[0025] S120, based on the calibration test bench and the first set, a second set of combinations of direct-axis current and quadrature-axis current under different voltages, different speeds, and different stator currents is obtained.

[0026] Specifically, based on the direct-axis current and quadrature-axis current pre-calibration results (first set) obtained by the virtual calibration platform, further calibration correction is required on the calibration bench to obtain multiple direct-axis current and quadrature-axis current combinations under different voltages, different speeds, and different stator currents, and the non-smooth points need to be corrected to determine the second set.

[0027] It should be noted that the calibration process of the calibration bench is basically the same as that of the virtual calibration, except that some parameter settings are slightly different and the parameter calibration step grid is larger, which can save calibration time and improve calibration efficiency.

[0028] S130 , determining a target set of combinations of direct-axis current and quadrature-axis current based on the first set and the second set.

[0029] Specifically, after obtaining the first set and the second set, the difference between the first set and the second set is compared using matlab / simulink, and the difference curves under different voltages, different speeds, and different stator currents are fitted. According to the calibration bench calibration correction, the second set and the difference curve obtained are fitted in matlab / simulink according to equal torque step and equal speed step under different voltages, different speeds, and different stator currents. Multiple direct-axis current and quadrature-axis current combinations are corrected and the non-smooth points are corrected to determine the target set of direct-axis current and quadrature-axis current combinations under different voltages, different speeds, and different stator currents.

[0030] The calibration method of the present application performs a round of pre-calibration on the direct-axis current and quadrature-axis current combination under different voltages, different speeds, and different stator currents based on a virtual calibration platform, and then performs secondary calibration verification on the direct-axis current and quadrature-axis current combination under different voltages, different speeds, and different stator currents on a motor calibration bench to determine the target set of direct-axis current and quadrature-axis current combinations. In this way, the calibration efficiency and calibration accuracy can be improved, and the motor calibration time can be shortened.

[0031] In some embodiments, a first set of direct-axis current and quadrature-axis current combinations under different voltages, different speeds, and different stator currents is obtained based on a virtual calibration platform, including: when the speed is less than or equal to a preset inflection point speed, obtaining the current motor operating condition; determining the direct-axis current and quadrature-axis current combinations and the motor torque under different current angles according to the current motor operating condition and the current stator current; determining the first target direct-axis current and quadrature-axis current combination under the current voltage, the current speed, and the current stator current according to the maximum value of the motor torque; and determining the first set according to the first target direct-axis current and quadrature-axis current combination under different voltages, different speeds, and different stator currents.

[0032] Specifically, the preset inflection point speed is 0.6-0.8 times the rated speed. However, due to the actual physical characteristics of the motor, there will be a certain difference between the theoretically calculated inflection point speed and the actual value. Therefore, the actual inflection point speed setting used to calibrate the inflection point speed will be smaller to ensure that the operating conditions below the inflection point speed will not enter weak magnetic field. The motor operating conditions include power generation conditions and electric conditions. The current motor operating conditions can be determined by obtaining the motor power direction. For example, if the power flows out of the supply system, it is determined that the motor is in a power generation condition. If the power is absorbed, the motor is in an electric condition. In order to obtain the first target direct-axis current and quadrature-axis current combination under different voltages, different speeds, and different stator currents, it is necessary to set the voltage to be calibrated. For example, the voltage to be calibrated is determined to be voltage 1, voltage 2, ..., voltage n. At each voltage to be calibrated, the speed to be calibrated is set. For example, the speed corresponding to voltage 1 can be speed 11, speed 12, ..., speed 1m. At each speed to be calibrated, the stator current to be calibrated is set. For example, the stator current corresponding to speed 11 can be stator current 111, stator current 112, ..., stator current 11p. At each stator current to be calibrated, the current angle to be calibrated is set. For example, the current angle corresponding to stator current 111 can be current angle 1111, current angle 1112, ..., current angle 111q, where the step size of the current angle can be 1°. If the current motor operating condition is an electric operating condition, the current angle 1111, the current angle 1112, ..., and the current angle 111q gradually increase. If the current motor operating condition is a power generation operating condition, the current angle 1111, the current angle 1112, ..., and the current angle 111q gradually decrease. If the current speed to be calibrated is less than or equal to the preset inflection point speed, the motor is controlled to operate at different current angles under the current voltage, the current speed, and the current stator current, and the torque sensor is used to detect the motor torque under different current angles, and the direct-axis current and quadrature-axis current combination corresponding to the maximum value of the motor torque is used as the first target direct-axis current and quadrature-axis current combination under the current voltage, the current speed, and the current stator current.

[0033] Exemplarily, it is assumed that the current voltage to be calibrated is voltage 1 (for example, voltage 1 may be the rated voltage), the current speed is speed 11 (for example, speed 11 may be 500 rpm), the current stator current is stator current 111 (for example, stator current 111 may be 20 A), and the current angle corresponding to stator current 111 is current angle 1111, current angle 1112, ..., current angle 111q. A combination 1111 of the direct-axis current and the quadrature-axis current corresponding to current angle 1111 and a corresponding motor torque 1111 are obtained, a combination 1112 of the direct-axis current and the quadrature-axis current corresponding to current angle 1112 and a corresponding motor torque 1112 are obtained, ..., a combination 111q of the direct-axis current and the quadrature-axis current corresponding to current angle 111q and a corresponding motor torque 111q are obtained. Compare motor torque 1111, motor torque 1112, …, motor torque 111q. If motor torque 1111 is the maximum value, the direct-axis current and quadrature-axis current combination 1111 corresponding to motor torque 1111 is used as the first target direct-axis current and quadrature-axis current combination under the current voltage (voltage 1), the current speed (speed 11), and the current stator current (stator current 111).

[0034] Further, according to the above method, when the rotation speed is less than or equal to the preset inflection point rotation speed, a first target direct-axis current and quadrature-axis current combination under different voltages, different rotation speeds, and different stator currents is obtained.

[0035] In some embodiments, a first set of direct-axis current and quadrature-axis current combinations under different voltages, different speeds, and different stator currents is obtained based on a virtual calibration platform, including: when the speed is greater than a preset inflection point speed, the voltage utilization rate is obtained; when the voltage utilization rate is less than the required voltage utilization rate, the direct-axis current and quadrature-axis current combinations under different current angles and the motor torque are determined according to the current motor operating condition and the current stator current, and the first target direct-axis current and quadrature-axis current combination under the current voltage, the current speed, and the current stator current is determined according to the maximum value of the motor torque; when the voltage utilization rate is greater than or equal to the required voltage utilization rate, the step size of the current angle is reduced, and the direct-axis current and quadrature-axis current combinations under different current angles and the motor torque are determined according to the current motor operating condition and the current stator current, and the first target direct-axis current and quadrature-axis current combination under the current voltage, the current speed, and the current stator current is determined according to the maximum value of the motor torque; the first set is determined according to the first target direct-axis current and quadrature-axis current combination under different voltages, different speeds, and different stator currents.

[0036] Specifically, if the current speed that needs to be calibrated is greater than the preset inflection point speed, the voltage utilization rate needs to be obtained in real time. The voltage utilization rate is calculated based on the bus voltage and the direct-axis voltage and quadrature-axis voltage. The voltage utilization rate is compared with the required voltage utilization rate to further determine the method for determining the target direct-axis current and quadrature-axis current combination.

[0037] Exemplarily, when the voltage utilization is less than the required voltage utilization, the method for determining the first target direct-axis current and quadrature-axis current combination is consistent with the method for determining when the speed is less than or equal to the preset inflection point speed, which has been described in detail in the above embodiments and will not be repeated here. When the voltage utilization is greater than or equal to the required voltage utilization, the step size of the current angle is reduced. For example, the step size of the current angle can be 0.05°, and the current angle to be calibrated is continued to be set based on the current angle calibrated by the previous stator current. For example, when the current angle that needs to be calibrated is determined to be current angle 1113 under the current stator current, and the voltage utilization is detected to be greater than or equal to the required voltage utilization, the determined current angle 1113, current angle 1112 and current angle 1111 are discarded, and the current angle that needs to be calibrated is continued to be set on the basis of the current angle 1111 calibrated by the previous stator current. If the current motor working condition is the electric working condition, the current angle corresponding to the current stator current needs to be gradually increased on the basis of the current angle 1111 with a step size of 0.05°. If the current motor working condition is the power generation working condition, the current angle corresponding to the current stator current needs to be gradually reduced on the basis of the current angle 1111 with a step size of 0.05°. In this way, by reducing the step size of the current angle, it is possible to avoid missing the first target direct-axis current and quadrature-axis current combination to a certain extent.

[0038] Under the current voltage, current speed, and current stator current, the motor is controlled to operate at different current angles, and a torque sensor is used to detect the motor torque under different current angles. The direct-axis current and quadrature-axis current combination corresponding to the maximum value of the motor torque is used as the first target direct-axis current and quadrature-axis current combination under the current voltage, current speed, and current stator current.

[0039] It should be noted that the step length of the current angle when the voltage utilization rate is less than the required voltage utilization rate is greater than the step length of the current angle when the voltage utilization rate is greater than or equal to the required voltage utilization rate.

[0040] Further, according to the above method, when the rotation speed is greater than the preset inflection point rotation speed, a first target direct-axis current and quadrature-axis current combination under different voltages, different rotation speeds, and different stator currents is obtained.

[0041] In summary, the first set is determined based on the first target direct-axis current and cross-axis current combination under different voltages, different speeds, and different stator currents when the speed is less than the preset inflection point speed and the first target direct-axis current and cross-axis current combination under different voltages, different speeds, and different stator currents when the speed is greater than the preset inflection point speed.

[0042] In some embodiments, direct-axis current and quadrature-axis current combinations under different current angles are determined based on the current motor operating condition and the current stator current, including: when the current motor operating condition is an electric operating condition, controlling the current angle to increase from a first preset angle to a second preset angle according to a first current angle step to obtain multiple direct-axis current and quadrature-axis current combinations; when the current motor operating condition is a power generation condition, controlling the current angle to decrease from a third preset angle to a second preset angle according to a second current angle step to obtain multiple direct-axis current and quadrature-axis current combinations, wherein the current angle is the angle between the stator current and the quadrature-axis current.

[0043] Specifically, at each stator current that needs to be calibrated, set the current angle that needs to be calibrated, refer to Figure 2 The current angle is the angle between the stator current and the quadrature-axis current. However, under different motor operating conditions, the setting method of the current angle for each stator current that needs to be calibrated is different.

[0044] Exemplarily, if the current motor operating condition is an electric operating condition, the current angle is controlled to increase from a first preset angle (e.g., 0°) to a second preset angle (e.g., 90°) according to a first current angle step (e.g., 1°), generating multiple current angles that need to be calibrated, such as 0°, 1°, ..., 90°, and determining the corresponding direct-axis current and quadrature-axis current combination according to each current angle. If the current motor operating condition is a power generation condition, the current angle is controlled to decrease from a third preset angle (e.g., 180°) to a second preset angle (e.g., 90°) according to a second current angle step (e.g., 1°), generating multiple current angles that need to be calibrated, such as 180°, 179°, ..., 90°, and determining the corresponding direct-axis current and quadrature-axis current combination according to each current angle.

[0045] It should be noted that as the stator current increases, the current angle generally shows an increasing / decreasing relationship. The automatic calibration software needs to be designed to compare with at least the previous two current points. When an abrupt current angle point appears, the initial current angle of the stator current point is the current angle corresponding to the last calibrated stator current, and then the step size of the current angle is reduced, for example, scanning the points with a step size of 0.5 times the original current angle.

[0046] In some embodiments, different voltages include the rated voltage, maximum allowable voltage and minimum allowable voltage of the motor, the stator current increases according to the first current step, and the speed increases according to the first speed step until the preset maximum speed is reached. At the current voltage and current speed, if the speed is greater than the preset inflection point speed and the motor power corresponding to the current stator current is greater than the preset maximum motor power or the motor power change rate is less than the preset change rate, the speed is increased according to the first speed step; at the current voltage and current speed, if the speed is less than or equal to the preset inflection point speed and the current stator current is greater than the preset maximum current or the motor power corresponding to the current stator current is greater than the preset maximum motor power, the speed is increased according to the first speed step. Among them, the preset maximum motor power, the preset change rate and the preset maximum current are all determined according to the actual situation, the first current step can also be determined according to the actual situation, and the first speed step is obtained according to the principle of preset maximum speed / integer multiple, and no specific restrictions are made here. Specifically, the voltage to be calibrated is the rated voltage, maximum allowable voltage and minimum allowable voltage of the motor. At each voltage that needs to be calibrated, the speed that needs to be calibrated is set, that is, the speed is controlled to increase according to the first speed step. For example, the speed set corresponding to the current voltage can be speed 11, speed 12, ..., speed 1m, wherein speed 11>speed 12>...>speed 1m, the difference between speed 12 and speed 11 is the first speed step, and speed 1m is the preset maximum speed. That is to say, when the speed set corresponding to the current voltage reaches the preset maximum speed, the calibration of the current voltage is stopped and the calibration of the next voltage is started.

[0047] At each speed that needs to be calibrated, the stator current that needs to be calibrated is set, that is, the stator current is controlled to increase according to the first current step. For example, the stator current set corresponding to the speed 11 can be stator current 111, stator current 112,…, stator current 11p, and stator current 111>stator current 112>…>stator current 11p.

[0048] At the current voltage and current speed, if the speed is greater than the preset inflection point speed and the motor power corresponding to the current stator current is greater than the preset maximum motor power or the motor power change rate is less than the preset change rate, then stop the calibration of the current speed and start the calibration of the next speed. At the current voltage and current speed, if the speed is less than or equal to the preset inflection point speed and the current stator current is greater than the preset maximum current or the motor power corresponding to the current stator current is greater than the preset maximum motor power, then stop the calibration of the current speed and start the calibration of the next speed.

[0049] It should be noted that when the speed is greater than the preset inflection point speed and the actual voltage utilization is greater than the required voltage utilization, the current angle needs to be set to 90° before increasing the speed to the target speed to ensure a certain direct-axis weak magnetic current without losing control.

[0050] In some embodiments, in the second set obtained based on the calibration test bench, the step size of the stator current increase is greater than the step size of the stator current increase in the first set obtained based on the virtual test bench, and in the second set obtained based on the calibration test bench, the step size of the speed increase is greater than the step size of the speed increase in the first set obtained based on the virtual test bench. Based on the calibration test bench and the first set, a second set of direct-axis current and quadrature-axis current combinations under different voltages, different speeds, and different stator currents is obtained, including: when the speed is less than or equal to the preset inflection point speed, determining the initial value of the current angle according to the current stator current and the target direct-axis current and quadrature-axis current combination corresponding to the current stator current in the first set; determining the direct-axis current and quadrature-axis current combination and the motor torque under different current angles according to the initial value of the current angle; determining the second target direct-axis current and quadrature-axis current combination under the current voltage, current speed, and current stator current according to the maximum value of the motor torque; and determining the second set according to the second target direct-axis current and quadrature-axis current combination under different voltages, different speeds, and different stator currents.

[0051] Specifically, when performing secondary calibration based on the calibration bench to obtain the second set, in order to save calibration time and improve calibration efficiency, it is necessary to reduce the speed, stator current and current angle that need to be calibrated, so it is necessary to set the calibration step grid larger. In other words, the increase step of the stator current when calibrating based on the virtual calibration is smaller than the increase step of the stator current when performing secondary calibration based on the calibration bench, and the increase step of the speed when calibrating based on the virtual calibration is smaller than the increase step of the speed when performing secondary calibration based on the calibration bench. For example, the speed that needs to be calibrated is divided by the preset inflection point speed. When the speed is less than or equal to the preset inflection point speed, 2 to 3 speeds are set, and when the speed is greater than the preset inflection point speed, 2 to 3 speeds are also set.

[0052] In order to obtain the target direct-axis current and quadrature-axis current combination under different voltages, different speeds, and different stator currents, it is necessary to set the voltages that need to be calibrated. For example, the voltages that need to be calibrated may be voltage 1, voltage 2, ..., voltage n. At each voltage that needs to be calibrated, set the speed that needs to be calibrated. When the speed is less than or equal to the preset inflection point speed, only 2 to 3 speeds need to be set. For example, the speeds corresponding to voltage 1 may be speed 11, speed 12, and speed 13. Speed ​​11, speed 12, and speed 13 are all less than or equal to the preset inflection point speed. At each speed that needs to be calibrated, set the stator current that needs to be calibrated. The number of stator currents that need to be calibrated is less than the number of stator currents that need to be calibrated based on the virtual calibration platform. For example, the stator current corresponding to the speed 11 can be stator current 111, stator current 112, ..., stator current 11x, and when setting the current angle to be calibrated at each stator current to be calibrated, it is necessary to determine the initial value of the current angle according to each stator current to be calibrated and the target direct-axis current and quadrature-axis current combination corresponding to each stator current to be calibrated in the first set, and determine the current angle to be calibrated for each stator current to be calibrated based on the initial value of the current angle, for example, the current angle to be calibrated is determined by adding several angles and then subtracting several angles on the basis of the initial value of the current angle, wherein the current angle step size can be 1°, and the corresponding combination of direct-axis current and quadrature-axis current is determined according to each current angle. For example, the current angle initial value corresponding to the stator current 111 is the current angle initial value 111, the current angle initial value corresponding to the stator current 112 is the current angle initial value 112, ..., the current angle initial value corresponding to the stator current 11x is the current angle initial value 11x, and the current angle that needs to be calibrated for each stator current that needs to be calibrated is determined based on the current angle initial value, for example, based on the current angle initial value 111, the current angle that needs to be calibrated for the stator current 111 is determined to be the current angle initial value 111-1°, the current angle initial value 111-2°, the current angle initial value 111+1°, the current angle initial value 111+2°, and the current angle initial value 111. If the current speed that needs to be calibrated is less than or equal to the preset inflection point speed, then under the current voltage, current speed, and current stator current, the motor is controlled to run at different current angles, and the torque sensor is used to detect the motor torque under different current angles, and the direct-axis current and quadrature-axis current combination corresponding to the maximum value of the motor torque is used as the second target direct-axis current and quadrature-axis current combination under the current voltage, current speed, and current stator current.

[0053] For example, assuming that the current voltage to be calibrated is voltage 1 (for example, voltage 1 can be the rated voltage), the current speed is speed 11 (for example, speed 11 can be 500 rpm), and the current stator current is stator current 111 (for example, stator current 111 can be 20 A), the current angle corresponding to stator current 111 is current angle initial value 111-1°, current angle initial value 111-2°, current angle initial value 111+1°, current angle initial value 111+2°, and current angle initial value 111. Obtain the combination of direct-axis current and quadrature-axis current corresponding to the initial current angle value 111 and the corresponding motor torque 1, the initial current angle value 111-1° corresponds to the combination of direct-axis current and quadrature-axis current and the corresponding motor torque 2, the initial current angle value 111-2° corresponds to the combination of direct-axis current and quadrature-axis current and the corresponding motor torque 3, the initial current angle value 111+1° corresponds to the combination of direct-axis current and quadrature-axis current and the corresponding motor torque 4, and the initial current angle value 111+2° corresponds to the combination of direct-axis current and quadrature-axis current and the corresponding motor torque 5. Compare motor torque 1, motor torque 2, motor torque 3, motor torque 4, and motor torque 5. If motor torque 1 is the maximum value, the direct-axis current and quadrature-axis current combination 1 corresponding to motor torque 1 is used as the second target direct-axis current and quadrature-axis current combination under the current voltage (voltage 1), the current speed (speed 11), and the current stator current (stator current 111).

[0054] Furthermore, according to the above method, a second target direct-axis current and quadrature-axis current combination under different voltages, different speeds, and different stator currents is obtained when the speed is less than a preset inflection point speed.

[0055] In some embodiments, a second set of direct-axis current and quadrature-axis current combinations under different voltages, different speeds, and different stator currents is obtained based on the calibration test bench and the first set, including: when the speed is greater than a preset inflection point speed, obtaining the voltage utilization; when the voltage utilization is less than the required voltage utilization, determining the direct-axis current and quadrature-axis current combinations under different current angles according to the speed and different stator currents; when the voltage utilization is greater than or equal to the required voltage utilization, reducing the step size of the current angle, and determining the direct-axis current and quadrature-axis current combinations under different current angles and the motor torque according to the current stator current, and determining the second target direct-axis current and quadrature-axis current combinations under the current voltage, current speed, and current stator current according to the maximum value of the motor torque; determining the second set according to the second target direct-axis current and quadrature-axis current combinations under different voltages, different speeds, and different stator currents.

[0056] Specifically, if the current speed that needs to be calibrated is greater than the preset inflection point speed, the voltage utilization rate needs to be obtained. The voltage utilization rate is calculated based on the bus voltage and the direct-axis voltage and quadrature-axis voltage. The voltage utilization rate is compared with the required voltage utilization rate to further determine the method for determining the target direct-axis current and quadrature-axis current combination.

[0057] Exemplarily, when the voltage utilization is less than the required voltage utilization, the method for determining the target direct-axis current and cross-axis current combination is consistent with the method for determining when the speed is less than or equal to the preset inflection point speed, which has been described in detail in the above embodiments and will not be repeated here. When the voltage utilization is greater than or equal to the required voltage utilization, it is also necessary to determine the initial value of the current angle based on each stator current that needs to be calibrated and the target direct-axis current and cross-axis current combination corresponding to each stator current that needs to be calibrated in the first set, and determine the current angle that needs to be calibrated for each stator current that needs to be calibrated based on the initial value of the current angle. For example, the current angle that needs to be calibrated is determined by adding a few angles and then reducing a few angles based on the initial value of the current angle, but the step size of the current angle needs to be reduced, wherein the current angle step size can be 0.05°, for example, the initial value of the current angle corresponding to the stator current 111 is the initial value of the current angle. The initial value 111, the current angle initial value corresponding to the stator current 112 is the current angle initial value 112, ..., the current angle initial value corresponding to the stator current 11x is the current angle initial value 11x, and the current angle that needs to be calibrated for each stator current that needs to be calibrated is determined based on the current angle initial value. For example, based on the current angle initial value 111, the current angle that needs to be calibrated for the stator current 111 is determined to be the current angle initial value 111-0.05°, the current angle initial value 111-0.1°, the current angle initial value 111+0.05°, the current angle initial value 111+0.1°, and the current angle initial value 111. Under the current voltage, current speed, and current stator current, the motor is controlled to run at different current angles, and the torque sensor is used to detect the motor torque under different current angles, and the direct-axis current and quadrature-axis current combination corresponding to the maximum value of the motor torque is used as the second target direct-axis current and quadrature-axis current combination under the current voltage, current speed, and current stator current.

[0058] It should be noted that the step length of the current angle when the voltage utilization rate is less than the required voltage utilization rate is greater than the step length of the current angle when the voltage utilization rate is greater than or equal to the required voltage utilization rate.

[0059] Furthermore, according to the above method, a second target direct-axis current and quadrature-axis current combination under different voltages, different speeds, and different stator currents is obtained when the speed is greater than a preset inflection point speed.

[0060] In summary, the second set is determined based on the second target direct-axis current and cross-axis current combination under different voltages, different speeds, and different stator currents when the speed is less than the preset inflection point speed and the second target direct-axis current and cross-axis current combination under different voltages, different speeds, and different stator currents when the speed is greater than the preset inflection point speed.

[0061] In some embodiments, the direct-axis current and quadrature-axis current combinations and the motor torque at different current angles are determined based on the initial value of the current angle, including: controlling the initial value of the current angle to increase to a third preset angle according to a third current angle step to obtain multiple direct-axis current and quadrature-axis current combinations and the motor torque; controlling the initial value of the current angle to decrease to a fourth preset angle according to the third current angle step to obtain multiple direct-axis current and quadrature-axis current combinations and the motor torque.

[0062] Specifically, since the current angle that needs to be calibrated needs to be reduced during calibration based on the calibration bench, the current angle that needs to be calibrated needs to be determined based on the initial current angle value of each stator current that needs to be calibrated, wherein the initial current angle value needs to be determined based on each stator current that needs to be calibrated and the target direct-axis current and quadrature-axis current combination corresponding to each stator current that needs to be calibrated in the first set. For example, it is necessary to control the initial current angle value to increase to a third preset angle according to a third current angle step, and to control the initial current angle value to decrease to a fourth preset angle according to the third current angle step, so as to determine the current angle corresponding to the current stator current, and determine the direct-axis current and quadrature-axis current combination and the motor torque under different current angles.

[0063] Exemplarily, when the current speed that needs to be calibrated is less than or equal to the preset inflection point speed, or when the current speed that needs to be calibrated is greater than the preset inflection point speed and the voltage utilization is less than the required voltage utilization, assuming that the initial current angle value corresponding to the current stator current is 20°, the initial current angle value is controlled to increase to a third preset angle (for example, 22°) according to a third current angle step of 1°, and the initial current angle value is controlled to decrease to a fourth preset angle (for example, 18°) according to the third current angle step of 1°, and the current angle corresponding to the current stator current is determined to be 18°, 19°, 20°, 21°, and 22°, and the direct-axis current and quadrature-axis current combinations and the motor torque at different current angles are determined.

[0064] When the current speed that needs to be calibrated is greater than the preset inflection point speed and the voltage utilization is greater than or equal to the required voltage utilization, assuming that the initial current angle value corresponding to the current stator current is 20°, the initial current angle value is controlled to increase to a third preset angle (for example, 21°) according to a third current angle step of 0.05°, and the initial current angle value is controlled to decrease to a fourth preset angle (for example, 19°) according to a third current angle step of 0.05°, and the current angle corresponding to the current stator current is determined to be 19°, 19.05°, 19.1°, …, 20°, 20.05°, 20.1°, …, 21°, and the direct-axis current and quadrature-axis current combinations and the motor torque at different current angles are determined.

[0065] In this way, the calibration efficiency can be improved, the calibration time can be shortened, and the temperature rise during the calibration process can be reduced, thereby reducing the impact of the temperature rise on the calibration accuracy.

[0066] In some embodiments, the method further includes: obtaining the temperature of the motor; when the temperature is greater than a preset temperature threshold, stopping calibration and data recording, reducing the stator current and speed until the temperature drops to a preset temperature, restoring the stator current and speed and starting automatic data recording. The preset temperature threshold and the preset temperature can be calibrated according to actual conditions, and no specific limitation is made here.

[0067] Specifically, if the calibration time is too long, the motor temperature will rise, which will have a great impact on the motor parameters and thus affect the calibration accuracy. Therefore, the motor temperature needs to be obtained during the calibration process. The motor temperature can be detected and obtained by the temperature sensor installed on the motor. The motor temperature is compared with the preset temperature threshold to determine whether the calibration needs to be stopped.

[0068] Exemplarily, if the temperature is greater than a preset temperature threshold, calibration and data recording are stopped, the stator current and speed are reduced until the temperature drops to a preset temperature, then the stator current and speed are restored and automatic data recording is started; if the temperature is less than or equal to the preset temperature threshold, calibration and data recording are continued.

[0069] In this way, the influence of excessive motor temperature on motor calibration can be avoided to a certain extent.

[0070] In some embodiments, when calibrating based on the virtual calibration platform, obtaining the direct-axis current and the quadrature-axis current can follow the target current and respond to motor controller parameters that meet the requirements as target controller parameters.

[0071] Specifically, before loading the calibration software of the target electric drive system and executing the current calibration based on the virtual calibration platform, the motor controller parameters need to be calibrated. Set different torque conditions at different speeds, and continuously adjust the controller parameters, such as PI (proportional-integral) parameters, until the feedback direct-axis current and quadrature-axis current can follow the target current and the response meets the requirements, and use the current controller parameters as the target controller parameters. When calibrating based on the calibration bench, input the target controller parameters obtained during the calibration based on the virtual calibration platform, and observe whether the feedback direct-axis current and quadrature-axis current can follow the target current and the response meets the requirements. If it is observed that the feedback direct-axis current and quadrature-axis current cannot follow the target current and the response does not meet the requirements, the target controller parameters are fine-tuned to ensure that the feedback direct-axis current and quadrature-axis current can follow the target current and the response meets the requirements. In this way, the parameter matching and debugging time of the actual calibration process and the risks of overcurrent caused by parameter mismatch can be saved.

[0072] In summary, the calibration method of the present application performs a round of pre-calibration on the direct-axis current and quadrature-axis current combination under different voltages, different speeds, and different stator currents based on the virtual calibration platform, and then performs secondary calibration verification on the direct-axis current and quadrature-axis current combination under different voltages, different speeds, and different stator currents on the motor calibration bench to determine the target set of direct-axis current and quadrature-axis current combinations. In this way, the calibration efficiency and calibration accuracy can be improved, and the motor calibration time can be shortened.

[0073] Corresponding to the above embodiment, the present application also proposes a current calibration device based on virtual calibration technology. Figure 3 The current calibration device 300 based on the virtual calibration technology includes: a first acquisition module 310 , a second acquisition module 320 and a determination module 330 .

[0074] Among them, the first acquisition module 310 is used to acquire a first set of direct-axis current and quadrature-axis current combinations under different voltages, different speeds, and different stator currents based on the virtual calibration platform. The second acquisition module 320 is used to acquire a second set of direct-axis current and quadrature-axis current combinations under different voltages, different speeds, and different stator currents based on the calibration bench and the first set. The determination module 330 is used to determine a target set of direct-axis current and quadrature-axis current combinations based on the first set and the second set.

[0075] According to one embodiment of the present application, the first acquisition module 310 is specifically used to obtain the current motor operating condition when the speed is less than or equal to the preset inflection point speed; determine the direct-axis current and quadrature-axis current combination and the motor torque at different current angles according to the current motor operating condition and the current stator current; determine the first target direct-axis current and quadrature-axis current combination at the current voltage, the current speed, and the current stator current according to the maximum value of the motor torque; determine the first set according to the first target direct-axis current and quadrature-axis current combination at different voltages, different speeds, and different stator currents.

[0076] According to one embodiment of the present application, the first acquisition module 310 is specifically used to obtain the voltage utilization when the speed is greater than the preset inflection point speed; when the voltage utilization is less than the required voltage utilization, determine the direct-axis current and quadrature-axis current combination at different current angles and the motor torque according to the current motor operating condition and the current stator current, and determine the first target direct-axis current and quadrature-axis current combination at the current voltage, the current speed, and the current stator current according to the maximum value of the motor torque; when the voltage utilization is greater than or equal to the required voltage utilization, reduce the step size of the current angle, and determine the direct-axis current and quadrature-axis current combination at different current angles and the motor torque according to the current motor operating condition and the current stator current, and determine the first target direct-axis current and quadrature-axis current combination at the current voltage, the current speed, and the current stator current according to the maximum value of the motor torque; determine the first set according to the first target direct-axis current and quadrature-axis current combination at different voltages, different speeds, and different stator currents.

[0077] According to one embodiment of the present application, the first acquisition module 310 is also used to, when the current motor operating condition is an electric operating condition, control the current angle to increase from a first preset angle to a second preset angle according to a first current angle step size to obtain multiple direct-axis current and quadrature-axis current combinations; when the current motor operating condition is a power generation condition, control the current angle to decrease from a third preset angle to a second preset angle according to a second current angle step size to obtain multiple direct-axis current and quadrature-axis current combinations, wherein the current angle is the angle between the stator current and the quadrature-axis current.

[0078] According to one embodiment of the present application, the different voltages include the rated voltage, the maximum allowable voltage, and the minimum allowable voltage of the motor, the stator current increases according to the first current step, and the speed increases according to the first speed step until the preset maximum speed is reached. At the current voltage and the current speed, if the speed is greater than the preset inflection point speed and the motor power corresponding to the current stator current is greater than the preset maximum motor power or the motor power change rate is less than the preset change rate, the speed is increased according to the first speed step; at the current voltage and the current speed, if the speed is less than or equal to the preset inflection point speed and the current stator current is greater than the preset maximum current or the motor power corresponding to the current stator current is greater than the preset maximum motor power, the speed is increased according to the first speed step.

[0079] According to one embodiment of the present application, in the second set obtained based on the calibration test bench, the step size of the stator current increase is greater than the step size of the stator current increase in the first set obtained based on the virtual test bench, and in the second set obtained based on the calibration test bench, the step size of the speed increase is greater than the step size of the speed increase in the first set obtained based on the virtual test bench. The second acquisition module 320 is specifically used to, when the speed is less than or equal to the preset inflection point speed, determine the initial value of the current angle according to the current stator current and the target direct-axis current and quadrature-axis current combination corresponding to the current stator current in the first set; determine the direct-axis current and quadrature-axis current combination and the motor torque under different current angles according to the initial value of the current angle; determine the second target direct-axis current and quadrature-axis current combination under the current voltage, the current speed, and the current stator current according to the maximum value of the motor torque; and determine the second set according to the second target direct-axis current and quadrature-axis current combination under different voltages, different speeds, and different stator currents.

[0080] According to one embodiment of the present application, the second acquisition module 320 is specifically used to obtain the voltage utilization when the rotational speed is greater than the preset inflection point rotational speed; when the voltage utilization is less than the required voltage utilization, determine the direct-axis current and quadrature-axis current combination at different current angles according to the rotational speed and different stator currents; when the voltage utilization is greater than or equal to the required voltage utilization, reduce the step size of the current angle, and determine the direct-axis current and quadrature-axis current combination at different current angles and the motor torque according to the current stator current, and determine the second target direct-axis current and quadrature-axis current combination at the current voltage, current rotational speed, and current stator current according to the maximum value of the motor torque; determine the second set according to the second target direct-axis current and quadrature-axis current combination at different voltages, different rotational speeds, and different stator currents.

[0081] According to one embodiment of the present application, the second acquisition module 320 is also used to control the initial value of the current angle to increase to a third preset angle according to a third current angle step to obtain multiple direct-axis current and quadrature-axis current combinations and motor torque; control the initial value of the current angle to decrease to a fourth preset angle according to the third current angle step to obtain multiple direct-axis current and quadrature-axis current combinations and motor torque.

[0082] It should be pointed out that the above explanation of the embodiments and beneficial effects of the current calibration method based on virtual calibration technology is also applicable to the current calibration device based on virtual calibration technology in the embodiments of the present application. To avoid redundancy, it will not be elaborated here.

[0083] Corresponding to the above embodiments, the present application also proposes a motor.

[0084] See also Figure 4As shown, the motor 400 of the present application includes a memory 410, a processor 420, and a current calibration program based on virtual calibration technology that is stored in the memory 410 and can be run on the processor 420. When the processor executes the current calibration program based on virtual calibration technology, the aforementioned current calibration method based on virtual calibration technology is implemented.

[0085] It should be pointed out that the above-mentioned explanation of the embodiments and beneficial effects of the current calibration method based on the virtual calibration technology is also applicable to the motor of the embodiment of the present application. In order to avoid redundancy, it will not be elaborated here.

[0086] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection portion with one or more wirings (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0087] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0088] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0089] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0090] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0091] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A current calibration method based on virtual calibration technology, characterized in that: The method comprises: Based on the virtual calibration platform, a first set of direct-axis current and quadrature-axis current combinations under different voltages, different speeds, and different stator currents is obtained; Acquire a second set of direct-axis current and quadrature-axis current combinations under different voltages, different speeds, and different stator currents based on the calibration bench and the first set; A target set of direct-axis current and quadrature-axis current combinations is determined based on the first set and the second set.

2. The method according to claim 1, characterized in that: A first set of direct-axis current and quadrature-axis current combinations under different voltages, different speeds, and different stator currents is obtained based on a virtual calibration platform, including: When the rotation speed is less than or equal to the preset inflection point rotation speed, obtaining the current motor operating condition; Determining a combination of direct-axis current and quadrature-axis current and a motor torque at different current angles according to the current motor operating condition and the current stator current; Determining a first target direct-axis current and quadrature-axis current combination under a current voltage, a current speed, and a current stator current according to the maximum value of the motor torque; The first set is determined according to a combination of first target direct-axis current and quadrature-axis current under different voltages, different speeds, and different stator currents.

3. The method according to claim 2, characterized in that A first set of direct-axis current and quadrature-axis current combinations under different voltages, different speeds, and different stator currents is obtained based on a virtual calibration platform, including: When the rotation speed is greater than the preset inflection point rotation speed, obtaining a voltage utilization rate; In the case where the voltage utilization rate is less than the required voltage utilization rate, the direct-axis current and quadrature-axis current combinations under the different current angles and the motor torque are determined according to the current motor operating condition and the current stator current, and a first target direct-axis current and quadrature-axis current combination under the current voltage, the current speed, and the current stator current is determined according to the maximum value of the motor torque; When the voltage utilization rate is greater than or equal to the required voltage utilization rate, the step size of the current angle is reduced, and the direct-axis current and quadrature-axis current combinations and the motor torque at different current angles are determined according to the current motor operating condition and the current stator current, and the first target direct-axis current and quadrature-axis current combination under the current voltage, the current speed, and the current stator current is determined according to the maximum value of the motor torque; The first set is determined according to a combination of first target direct-axis current and quadrature-axis current under different voltages, different speeds, and different stator currents.

4. The method according to claim 2 or 3, characterized in that: Determining the direct-axis current and quadrature-axis current combinations at different current angles according to the current motor operating condition and the current stator current includes: When the current motor operating state is an electric operating state, controlling the current angle to increase from a first preset angle to a second preset angle according to a first current angle step length, so as to obtain a plurality of direct-axis current and quadrature-axis current combinations; When the current motor operating condition is a power generation condition, the current angle is controlled to decrease from a third preset angle to the second preset angle according to a second current angle step to obtain multiple direct-axis current and quadrature-axis current combinations, wherein the current angle is the angle between the stator current and the quadrature-axis current.

5. The method according to claim 4, characterized in that The different voltages include a rated voltage, a maximum allowable voltage, and a minimum allowable voltage of the motor, the stator current increases according to a first current step, and the speed increases according to a first speed step until a preset maximum speed is reached; At the current voltage and current speed, if the speed is greater than the preset inflection point speed and the motor power corresponding to the current stator current is greater than the preset maximum motor power or the motor power change rate is less than the preset change rate, the speed is increased according to the first speed step; Under the current voltage and current speed, if the speed is less than or equal to the preset inflection point speed and the current stator current is greater than the preset maximum current or the motor power corresponding to the current stator current is greater than the preset maximum motor power, the speed is increased according to the first speed step.

6. The method according to claim 1, characterized in that In the second set obtained based on the calibration test bench, the step length of stator current increase is greater than the step length of stator current increase in the first set obtained based on the virtual test bench; in the second set obtained based on the calibration test bench, the step length of speed increase is greater than the step length of speed increase in the first set obtained based on the virtual test bench; a second set of direct-axis current and quadrature-axis current combinations under different voltages, different speeds, and different stator currents is obtained based on the calibration test bench and the first set, including: When the rotation speed is less than or equal to the preset inflection point rotation speed, determining the initial value of the current angle according to the current stator current and the target direct-axis current and quadrature-axis current combination corresponding to the current stator current in the first set; Determine the combination of direct-axis current and quadrature-axis current and the motor torque at different current angles according to the initial value of the current angle; Determining a second target direct-axis current and quadrature-axis current combination under a current voltage, a current speed, and a current stator current according to the maximum value of the motor torque; The second set is determined according to a second target direct-axis current and quadrature-axis current combination under different voltages, different speeds, and different stator currents.

7. The method according to claim 6, characterized in that Acquiring a second set of direct-axis current and quadrature-axis current combinations under different voltages, different speeds, and different stator currents based on the calibration bench and the first set, including: When the rotation speed is greater than the preset inflection point rotation speed, obtaining a voltage utilization rate; When the voltage utilization rate is less than the required voltage utilization rate, determining the combination of direct-axis current and quadrature-axis current under different current angles according to the rotation speed and the different stator currents; When the voltage utilization rate is greater than or equal to the required voltage utilization rate, the step size of the current angle is reduced, and the direct-axis current and quadrature-axis current combinations and the motor torque at different current angles are determined according to the current stator current, and the second target direct-axis current and quadrature-axis current combination under the current voltage, the current speed, and the current stator current is determined according to the maximum value of the motor torque; The second set is determined according to a second target direct-axis current and quadrature-axis current combination under different voltages, different speeds, and different stator currents.

8. The method according to claim 6, characterized in that Determining the direct-axis current and quadrature-axis current combinations and the motor torque at different current angles according to the initial value of the current angle includes: Controlling the initial value of the current angle to increase to a third preset angle according to a third current angle step length, so as to obtain a plurality of direct-axis current and quadrature-axis current combinations and motor torque; The initial value of the current angle is controlled to decrease to a fourth preset angle according to the third current angle step size, so as to obtain a plurality of direct-axis current and quadrature-axis current combinations and motor torque.

9. A current calibration device based on virtual calibration technology, characterized in that: The device comprises: A first acquisition module, used for acquiring a first set of direct-axis current and quadrature-axis current combinations under different voltages, different speeds, and different stator currents based on a virtual calibration platform; A second acquisition module, used for acquiring a second set of combinations of direct-axis current and quadrature-axis current under different voltages, different speeds, and different stator currents based on the calibration bench and the first set; A determination module is configured to determine a target set of combinations of direct-axis current and quadrature-axis current based on the first set and the second set.

10. A motor, characterized in that: It comprises a memory, a processor and a current calibration program based on virtual calibration technology which is stored in the memory and can be run on the processor. When the processor executes the current calibration program based on virtual calibration technology, it implements the current calibration method based on virtual calibration technology according to any one of claims 1-8.

Images