阅读说明：本技术 用于电机的控制方法和控制装置、汽车以及存储介质 (Control method and control device for an electric machine, motor vehicle and storage medium ) 是由 王洋洋 朱福堂 鲁超 于 2019-11-29 设计创作，主要内容包括：本发明实施方式提供一种用于电机的控制方法和控制装置、汽车以及存储介质,属于电机领域。所述控制方法包括：获取所述电机的控制参数；根据所述控制参数计算所述电机的固有参数；根据计算得到的所述固有参数修正电机的预定控制模型；以及基于修正后的所述预定控制模型对所述电机进行控制。在上述技术方案中,通过计算电机实际的固有参数,并基于实际的固有参数修正电机的预定控制模型,可以降低由于电机老化或制造差异对电机的控制精度的影响,进而提高电机的控制精度和工作效率,降低电机能耗,并且使电机控制更平稳。(The embodiment of the invention provides a control method and a control device for a motor, an automobile and a storage medium, and belongs to the field of motors. The control method comprises the following steps: acquiring control parameters of the motor; calculating intrinsic parameters of the motor according to the control parameters; correcting a preset control model of the motor according to the inherent parameters obtained by calculation; and controlling the motor based on the corrected preset control model. In the technical scheme, the actual intrinsic parameters of the motor are calculated, and the preset control model of the motor is corrected based on the actual intrinsic parameters, so that the influence of motor aging or manufacturing difference on the control precision of the motor can be reduced, the control precision and the working efficiency of the motor are improved, the energy consumption of the motor is reduced, and the motor is controlled more stably.)

1. A control method for an electric motor that is controlled based on a predetermined control model, characterized by comprising:

acquiring control parameters of the motor;

calculating intrinsic parameters of the motor according to the control parameters;

correcting the preset control model according to the inherent parameters obtained by calculation; and

and controlling the motor based on the corrected preset control model.

2. The control method according to claim 1, wherein the control parameters include quadrature-axis current, direct-axis current, and direct-axis voltage of the motor, the intrinsic parameters include quadrature-axis inductance and direct-axis inductance of the motor, and the calculating the intrinsic parameters of the motor from the control parameters includes:

calculating the direct axis inductance and the quadrature axis inductance according to the quadrature axis current, the direct axis current and the direct axis voltage, wherein

The direct axis inductance is calculated based on the following formula:

the quadrature axis inductance is calculated based on the following formula:

wherein the content of the first and second substances,is an estimate of the direct-axis inductance,is an estimate of the quadrature inductance, k_i1、k_i2For PI regulation parameters, d τ is the time constant, L_d(0) The direct axis inductance, L, currently stored for the preset control model_q(0) The quadrature axis inductance, i, currently stored for the preset control model_dFor the value of the look-up table of the direct axis current, i, determined on the basis of the preset control model_qFor the look-up table value of the quadrature axis current determined based on the preset control model,is an estimate of the direct-axis current,is an estimate of the quadrature axis current,is an estimate of the direct axis voltage.

3. The control method according to claim 2, wherein the motor is a permanent magnet synchronous motor, the intrinsic parameters further include a permanent magnet flux linkage of the motor, the control method further comprising:

detecting an operating parameter of the motor corresponding to the control parameter;

the calculating the intrinsic parameters of the motor according to the control parameters further comprises: and calculating the permanent magnet flux linkage of the motor according to the control parameters and the operation parameters.

4. The control method of claim 3, wherein the operating parameter comprises an angular velocity of the motor, and wherein calculating the permanent magnet flux linkage of the motor from the control parameter and the operating parameter comprises:

calculating the permanent magnet flux linkage according to the quadrature axis current and the angular velocity based on the following formula:

wherein the content of the first and second substances,is an estimate of the permanent magnet flux linkage, k_i3Adjusting the parameter, omega, for PI_rFor said angular velocity, #_f(0) The permanent magnet flux linkage currently stored for the preset control model.

5. The control method according to any one of claims 1 to 4, characterized by further comprising:

determining the actual torque of the motor according to the control parameters and the inherent parameters obtained by calculation;

comparing the actual torque to a target torque; and

in the case where the actual torque is different from the target torque, a control parameter of the motor is adjusted so that the actual torque reaches the target torque.

6. The control method according to any one of claims 1 to 4, wherein the predetermined control model includes a predetermined correspondence between the control parameter and a target parameter of a motor, and the modifying the predetermined control model according to the calculated intrinsic parameter includes:

determining the latest corresponding relation between the control parameters and the target parameters according to the intrinsic parameters obtained by calculation; and

and replacing the predetermined corresponding relation with the latest corresponding relation when the latest corresponding relation is different from the predetermined corresponding relation.

7. The control method according to claim 6, wherein the motor is a permanent magnet synchronous motor, the control parameters include quadrature axis current and direct axis current of the motor, the intrinsic parameters include quadrature axis inductance, direct axis inductance, and permanent magnet flux linkage of the motor, the target parameters include quadrature axis flux linkage and direct axis flux linkage of the motor, and the determining the latest correspondence between the control parameters and the target parameters according to the calculated intrinsic parameters of the motor includes:

determining the latest corresponding relation between the quadrature axis current and the direct axis current and the quadrature axis magnetic linkage and the direct axis magnetic linkage according to the quadrature axis inductance, the direct axis inductance and the permanent magnet magnetic linkage obtained through calculation, wherein

The correspondence of the direct-axis current to the direct-axis flux linkage is determined based on the following formula:

the correspondence of the quadrature axis current to the quadrature axis flux linkage is determined based on the following formula:

wherein i_dFor the direct axis current, i_qFor the purpose of the quadrature axis current,is an estimate of the direct axis flux linkage,is an estimate of the quadrature axis flux linkage,is an estimate of the flux linkage of the permanent magnet,is an estimate of the direct-axis inductance,is an estimate of the quadrature inductance.

8. The control method according to claim 6, wherein the motor is a permanent magnet synchronous motor, the control parameters include quadrature axis current and direct axis current of the motor, the intrinsic parameters include quadrature axis inductance, direct axis inductance, and permanent magnet flux linkage of the motor, the target parameters include torque of the motor, and the determining the latest correspondence between the control parameters and the target parameters according to the calculated intrinsic parameters of the motor includes:

determining the latest corresponding relation between the quadrature axis current and the direct axis current and the torque based on the following formula according to the calculated quadrature axis inductance, the calculated direct axis inductance and the calculated permanent magnet flux linkage:

wherein i_dFor the direct axis current, i_qFor the purpose of the quadrature axis current,is an estimate of said torque, n_pIs the number of the magnetic pole pairs of the motor,is an estimate of the flux linkage of the permanent magnet,is an estimate of the direct-axis inductance,is an estimate of the quadrature inductance.

9. A control device for an electric machine, characterized in that the control device comprises: memory, a processor and a computer program stored on the memory and executable on the processor, the processor executing the computer program to implement the control method for an electric machine according to any one of claims 1 to 8.

10. An automobile, characterized in that the automobile comprises:

a motor; and

the control device for an electric motor according to claim 9.

11. A machine-readable storage medium, characterized in that instructions are stored thereon for enabling a processor to carry out the control method for an electric machine according to any one of claims 1 to 8 when executed by the processor.

Technical Field

The present invention relates to the field of motors, and in particular, to a control method and a control device for a motor, an automobile, and a storage medium.

Background

Currently, motors are widely used as core components of new energy vehicles. The motor of the new energy automobile generally adopts maximum torque current ratio control (MTPA), and the implementation method is to make characteristic parameters in the motor into a table look-up model and write a program to input the program into a motor controller to realize accurate control of the motor, namely to make torque Te and rotation speed n and direct shaft current i_dAnd quadrature axis current i_qCorresponding relation between them, straight axis flux linkage F_dAnd quadrature axis linkage F_qAnd the direct axis current i_dAnd quadrature axis current i_qThe corresponding relation between the two models is written into the control program. Therefore, the precise control of the motor is realized by a table look-up model, and therefore, the accuracy of the table look-up model data is very important for the control of the motor.

In the prior art, a table look-up model is generally made based on calibrated initial characteristic parameters of the motor to write a control program and input the control program into a motor controller of each vehicle to accurately control the motor. However, when a new energy automobile runs for many years, the motor of the new energy automobile is aged, so that the characteristic parameters (such as direct-axis inductance L) in the motor_dQuadrature axis inductor L_qAnd permanent magnet flux linkage psi_fEtc.) are changed. And when the motor meets extreme working conditions, the permanent magnet is demagnetized and other parameters are changed. However, under the condition that the characteristic parameters in the motor have changed, the control program in the motor controller still performs motor control based on the initial table look-up model, which may cause the motor controller to control the motor with insufficient accuracy and large error, and result in the reduction of motor efficiency and even vehicle efficiency, the increase of energy consumption, and the driving comfort degree may also be greatly affected.

In addition, when one motor is designed, a batch of motors is produced in batch, but the batch of motors is different due to differences in manufacturing processes and manufacturing levels. However, only a few motor samples of the batch of motors are generally calibrated, the internal characteristic parameters of the sample motors are used for representing the internal characteristic parameters of the whole batch of motors, the difference between the internal characteristic parameters is ignored, then the control program of the whole batch of motors is written based on the parameter data, and finally the control program is input into each motor controller. Therefore, due to the difference among the motors, the control precision and the performance of part of the motors are influenced by using the same control program, so that the whole vehicle efficiency and the energy consumption of the new energy vehicle adopting different motors are different.

Disclosure of Invention

To at least partially solve the above problems in the prior art, an object of an embodiment of the present invention is to provide a control method and a control device for a motor, a vehicle, and a storage medium.

In order to achieve the above object, in a first aspect of embodiments of the present invention, there is provided a control method for a motor that is controlled based on a predetermined control model, the control method including:

acquiring control parameters of the motor;

calculating intrinsic parameters of the motor according to the control parameters;

correcting the preset control model according to the inherent parameters obtained by calculation; and

and controlling the motor based on the corrected preset control model.

Optionally, the controlling parameters include quadrature axis current, direct axis current, and direct axis voltage of the motor, the intrinsic parameters include quadrature axis inductance and direct axis inductance of the motor, and the calculating the intrinsic parameters of the motor according to the controlling parameters includes:

calculating the direct axis inductance and the quadrature axis inductance according to the quadrature axis current, the direct axis current and the direct axis voltage, wherein

The direct axis inductance is calculated based on the following formula:

the quadrature axis inductance is calculated based on the following formula:

wherein the content of the first and second substances,is an estimate of the direct-axis inductance,is an estimate of the quadrature inductance, k_i1、k_i2For PI regulation parameters, d τ is the time constant, L_d(0) The direct axis inductance, L, currently stored for the preset control model_q(0) The quadrature axis inductance, i, currently stored for the preset control model_dFor the value of the look-up table of the direct axis current, i, determined on the basis of the preset control model_qFor the look-up table value of the quadrature axis current determined based on the preset control model,is an estimate of the direct-axis current,is an estimate of the quadrature axis current,is an estimate of the direct axis voltage.

Optionally, the motor is a permanent magnet synchronous motor, the intrinsic parameters further include a permanent magnet flux linkage of the motor, and the control method further includes:

detecting an operating parameter of the motor corresponding to the control parameter;

the calculating the intrinsic parameters of the motor according to the control parameters further comprises: and calculating the permanent magnet flux linkage of the motor according to the control parameters and the operation parameters.

Optionally, the operating parameter includes an angular velocity of the motor, and the calculating a permanent magnet flux linkage of the motor according to the control parameter and the operating parameter includes:

calculating the permanent magnet flux linkage according to the quadrature axis current and the angular velocity based on the following formula:

wherein the content of the first and second substances,is an estimate of the permanent magnet flux linkage, k_i3Adjusting the parameter, omega, for PI_rFor said angular velocity, #_f(0) The permanent magnet flux linkage currently stored for the preset control model.

Optionally, the control method further includes:

determining the actual torque of the motor according to the control parameters and the inherent parameters obtained by calculation;

comparing the actual torque to a target torque; and

in the case where the actual torque is different from the target torque, a control parameter of the motor is adjusted so that the actual torque reaches the target torque.

Optionally, the predetermined control model includes a predetermined correspondence between the control parameter and a target parameter of the motor, and the modifying the predetermined control model according to the calculated intrinsic parameter includes:

determining the latest corresponding relation between the control parameters and the target parameters according to the intrinsic parameters obtained by calculation; and

and replacing the predetermined corresponding relation with the latest corresponding relation when the latest corresponding relation is different from the predetermined corresponding relation.

Optionally, the motor is a permanent magnet synchronous motor, the control parameter includes quadrature axis current and direct axis current of the motor, the intrinsic parameter includes quadrature axis inductance, direct axis inductance, and permanent magnet flux linkage of the motor, the target parameter includes quadrature axis flux linkage and direct axis flux linkage of the motor, and determining the latest correspondence between the control parameter and the target parameter according to the intrinsic parameter of the motor obtained by calculation includes:

determining the latest corresponding relation between the quadrature axis current and the direct axis current and the quadrature axis magnetic linkage and the direct axis magnetic linkage according to the quadrature axis inductance, the direct axis inductance and the permanent magnet magnetic linkage obtained through calculation, wherein

The correspondence of the direct-axis current to the direct-axis flux linkage is determined based on the following formula:

the correspondence of the quadrature axis current to the quadrature axis flux linkage is determined based on the following formula:

wherein i_dFor the direct axis current, i_qFor the purpose of the quadrature axis current,is an estimate of the direct axis flux linkage,is an estimate of the quadrature axis flux linkage,is an estimate of the flux linkage of the permanent magnet,being said direct-axis inductorThe value of the estimated value is,is an estimate of the quadrature inductance.

Optionally, the motor is a permanent magnet synchronous motor, the control parameter includes quadrature axis current and direct axis current of the motor, the intrinsic parameter includes quadrature axis inductance, direct axis inductance, and permanent magnet flux linkage of the motor, the target parameter includes torque of the motor, and determining a latest correspondence between the control parameter and the target parameter according to the intrinsic parameter of the motor obtained by calculation includes:

determining the latest corresponding relation between the quadrature axis current and the direct axis current and the torque based on the following formula according to the calculated quadrature axis inductance, the calculated direct axis inductance and the calculated permanent magnet flux linkage:

wherein i_dFor the direct axis current, i_qFor the purpose of the quadrature axis current,is an estimate of said torque, n_pIs the number of the magnetic pole pairs of the motor,is an estimate of the flux linkage of the permanent magnet,is an estimate of the direct-axis inductance,is an estimate of the quadrature inductance.

In a second aspect of the embodiments of the present invention, there is also provided a control device for a motor, the control device including: a memory, a processor and a computer program stored on the memory and executable on the processor, the processor executing the computer program to implement the control method for an electric machine described above.

In a third aspect of the embodiments of the present invention, there is also provided an automobile including:

a motor; and

the control device for the motor is described above.

In a fourth aspect of embodiments of the present invention, there is also provided a machine-readable storage medium having stored thereon instructions for enabling a processor to execute the above-mentioned control method for a motor when the instructions are executed by the processor.

In the technical scheme, the actual intrinsic parameters of the motor are calculated, and the preset control model of the motor is corrected based on the actual intrinsic parameters, so that the influence of motor aging or manufacturing difference on the control precision of the motor can be reduced, the control precision and the working efficiency of the motor are improved, the energy consumption of the motor is reduced, and the motor is controlled more stably.

Additional features and advantages of embodiments of the invention will be set forth in the detailed description which follows.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the embodiments of the invention without limiting the embodiments of the invention. In the drawings:

fig. 1 is a flowchart illustrating a control method for a motor according to an embodiment of the present invention;

FIG. 2 illustrates a flow chart of a control method for an electric machine provided in an alternative embodiment of the present invention;

fig. 3 is a block diagram schematically illustrating a control apparatus for a motor according to an embodiment of the present invention; and

fig. 4 is a block diagram schematically illustrating an automobile according to an embodiment of the present invention.

Description of the reference numerals

10 control device 20 motor

11 processor 12 memory

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

Fig. 1 is a flowchart illustrating a control method for a motor according to an embodiment of the present invention. As shown in fig. 1, an embodiment of the present invention provides a control method for a motor, the motor being controlled based on a predetermined control model, the control method may include:

and step S11, acquiring control parameters of the motor.

The control parameters of the motor can include quadrature axis current, direct axis voltage and the like of the motor, and the motor can be controlled by adjusting the control parameters.

In step S12, the intrinsic parameters of the motor are calculated based on the control parameters of the motor.

Here, when the control parameter of the motor is acquired, the intrinsic parameter of the motor may be calculated based on the control parameter of the motor. The intrinsic parameters may include intrinsic parameters such as direct axis inductance and quadrature axis inductance. In step S12, the value of the intrinsic parameter calculated based on the control parameter is the current actual parameter value of the motor.

And step S13, correcting the preset control model according to the calculated intrinsic parameters.

In step S13, it should be noted that, since the predetermined control model is determined based on the initially calibrated intrinsic parameters of the motor, when the values of the current actual intrinsic parameters of the motor are different from the initially calibrated intrinsic parameters due to aging of the motor or manufacturing errors, the control of the motor using the predetermined control model has an influence on the control accuracy. Therefore, the control precision and the working efficiency of the motor can be improved by correcting the preset control model by using the actual intrinsic parameters obtained by calculation.

And step S14, controlling the motor based on the corrected preset control model.

In step S14, the original control model may be covered with the modified control model, and the motor controller of the motor controls the motor by using the modified control model, so as to improve the control accuracy and the working efficiency of the motor.

Therefore, the actual intrinsic parameters of the motor, such as the direct axis inductance, the quadrature axis inductance and the like, are calculated in real time or periodically, and the preset control model of the motor is corrected based on the actual intrinsic parameters, so that the influence of motor aging or manufacturing difference on the control precision of the motor can be reduced, the control precision and the working efficiency of the motor are improved, the energy consumption of the motor is reduced, and the motor is controlled more stably.

In an alternative embodiment of the present invention, the control parameters may include quadrature-axis current, direct-axis current, and direct-axis voltage of the motor, and the intrinsic parameters may include quadrature-axis inductance and direct-axis inductance of the motor. The step S12 may include: and calculating the direct-axis inductance and the quadrature-axis inductance according to the quadrature-axis current, the direct-axis current and the direct-axis voltage. Wherein, when the motor is operated, the direct axis inductance can be calculated based on the following formula (1):

the quadrature inductance may be calculated based on the following equation (2):

in the above-mentioned formula,is an estimated value of the direct-axis inductance determined by estimation, i.e. the current actual direct-axis inductance determined by estimation.Is an estimated value of the quadrature axis inductance determined by estimation, i.e. the current actual quadrature axis inductance determined by estimation. k is a radical of_i1、k_i2For PI regulation parameters, d τ is the time constant, L_d(0) Direct axis inductance, L, currently stored for a preset control model_q(0) The current stored quadrature axis inductance, i, for the preset control model_dFor the value of a look-up table of direct-axis currents, i, determined on the basis of a preset control model_qFor the look-up table value of the quadrature axis current determined based on the preset control model,is an estimate of the direct-axis current,is an estimate of the quadrature axis current,is an estimate of the direct axis voltage.

In particular, an estimation method may be used to determine the direct and quadrature inductances of the motor. During the operation of the motor, a table lookup value i of the direct-axis current corresponding to the current torque can be determined according to a preset control model_dAnd the table-look-up value i of the quadrature axis current_qAnd estimating the estimated value of the direct-axis current corresponding to the current torque according to the currently stored permanent magnet flux linkage, the direct-axis inductance and the quadrature-axis inductance and the combination of the current rotating speed, the direct-axis voltage, the quadrature-axis voltage and other parameters of the motorEstimation of quadrature currentAnd an estimate of the direct-axis voltageThis estimation step is prior art and therefore not described in detail. Then, the table lookup value i of the direct-axis current is compared_dAnd estimateEvaluating valueTable lookup value i of quadrature axis current_qAnd the estimated valueEstimation of direct axis voltageSubstituting into the above formula (1) and formula (2) to perform PI (proportional Integral) closed loop operation to obtain the estimated value of direct axis inductanceEstimate of quadrature inductanceIn the formula, PI adjusting parameters ki1 and ki2 and a time constant d tau number are all preset. And Ld (0) is a direct axis inductor currently stored by the preset control model, and Lq (0) is a quadrature axis inductor currently stored by the preset control model. And when the determined current actual direct axis inductance and the determined current actual quadrature axis inductance are different from the direct axis inductance and the quadrature axis inductance stored in the preset control model, replacing the previously stored direct axis inductance and quadrature axis inductance with the current actual direct axis inductance and quadrature axis inductance. Therefore, the direct axis inductance and the quadrature axis inductance stored in the preset control model can be corrected based on the deviation between the table look-up values of the direct axis current and the quadrature axis current and the estimated value estimated in real time through the method, so that the current actual direct axis inductance and quadrature axis inductance of the motor can be estimated more accurately. It is understood that the embodiment of the present invention may also use other existing calculation methods to determine the current actual direct-axis inductance and quadrature-axis inductance of the motor.

In an alternative embodiment of the present invention, the motor may be a permanent magnet synchronous motor, and more specifically, the motor may be an interior permanent magnet synchronous motor commonly used in new energy vehicles. The intrinsic parameters of the electrical machine may also include the permanent magnet flux linkage of the electrical machine. Prior to the above step S12, the control method for the motor may further include: and detecting the operation parameters of the motor corresponding to the control parameters of the motor. The step S12 may further include: and calculating the permanent magnet flux linkage of the motor according to the control parameters and the operation parameters of the motor.

The operating parameter of the motor may include an angular velocity of the motor, which may be detected directly or indirectly by a sensor mounted on the motor. The permanent magnet flux linkage of the motor can be calculated according to the quadrature axis current and the angular velocity of the motor. Specifically, the permanent magnet flux linkage of the motor may be calculated when the motor is running according to the following formula (3):

wherein the content of the first and second substances,is an estimate of the permanent magnet flux linkage of the machine determined by the estimation, i.e. the current actual permanent magnet flux linkage determined by the estimation. ki3 is a PI regulation parameter, which is predetermined. Omega_rFor the angular speed of the motor corresponding to the current torque, the angular speed ω_rThe detection determination may be made by a sensor. Psi_f(0) The permanent magnet flux linkage currently stored for the preset control model. i.e. i_qIs a table lookup value of quadrature axis current corresponding to the present torque determined based on a preset control model,is an estimate of the quadrature current corresponding to the present torque. Thus, by looking up the table value iq and the estimated value of the quadrature currentSubstituting into the formula (3) to perform PI closed loop operation to obtain the estimated value of the permanent magnet flux linkage

In an alternative embodiment of the present invention, the control method for the motor may further include:

and step S21, determining the actual torque of the motor according to the control parameters of the motor and the calculated intrinsic parameters.

In step S22, the actual torque of the motor is compared with the target torque.

In step S23, in the case where the actual torque of the motor is different from the target torque, the control parameter of the motor is adjusted so that the actual torque of the motor reaches the target torque.

Specifically, when the motor runs, intrinsic parameters of the motor such as direct axis inductance, quadrature axis inductance, permanent magnet flux linkage and the like under the current torque and rotating speed can be calculated according to quadrature axis current, direct axis voltage, quadrature axis voltage and angular speed, and after the direct axis inductance, the quadrature axis inductance and the permanent magnet flux linkage are determined, the current actual torque of the motor can be calculated by combining the quadrature axis current and the direct axis current. After determining the actual torque of the electric machine, the actual torque of the electric machine may be compared with a required target torque, which may be a torque allocated to the electric machine by a VCU (Vehicle control unit) of the new energy Vehicle in which the electric machine is located. If the actual torque is not equal to the target torque, the motor can be controlled according to the difference between the actual rotating shaft and the target torque, so that the actual torque of the motor reaches the target torque. For example, in the case where the actual torque is greater than the target torque, the motor controller may send a command to decrease the torque to the motor to decrease the torque of the motor, and in the case where the actual torque is less than the target torque, the motor controller may send a command to increase the torque to the motor to increase the torque of the motor.

In an alternative embodiment of the invention, the predetermined control model may comprise a predetermined correspondence between control parameters of the electric machine and target parameters of the electric machine, the predetermined correspondence being determined based on initially calibrated intrinsic parameters of the electric machine (e.g. direct axis inductance, quadrature axis inductance and permanent magnet flux linkage). The step S14 may include:

step S141, determining the latest correspondence between the control parameter and the target parameter according to the calculated intrinsic parameters.

And step S142, replacing the predetermined corresponding relation with the latest corresponding relation when the latest corresponding relation is different from the predetermined corresponding relation.

Specifically, the motor may be, for example, a permanent magnet synchronous motor, the control parameters of the motor may include quadrature axis current and direct axis current of the motor, the intrinsic parameters of the motor may include quadrature axis inductance, direct axis inductance, and permanent magnet flux linkage of the motor, and the target parameters of the motor may include quadrature axis flux linkage, direct axis flux linkage, torque, and rotational speed of the motor. After the motor design is completed, the quadrature axis inductance, the direct axis inductance and the permanent magnet flux linkage of the motor can be calibrated according to a motor sample, and then a control model (namely a preset control model) of the motor is determined based on the calibrated quadrature axis inductance, the calibrated direct axis inductance and the calibrated permanent magnet flux linkage. The predetermined control model may include a correspondence (i.e., a predetermined correspondence) between a control parameter determined based on the calibrated quadrature-axis inductance, the direct-axis inductance, and the permanent magnet flux linkage and a target parameter. The predetermined correspondence relationship may specifically include a correspondence relationship between quadrature-axis current and direct-axis current and quadrature-axis flux linkage and direct-axis flux linkage, and a correspondence relationship between quadrature-axis current and direct-axis current and torque and rotation speed.

In the running process of the motor, the quadrature axis inductance, the direct axis inductance and the permanent magnet flux linkage under the current rotating speed and torque can be calculated according to the current quadrature axis current, the current of the direct axis, the voltage of the direct axis and the angular speed, the latest corresponding relation between the quadrature axis current and the current of the direct axis and the quadrature axis flux linkage and the direct axis flux linkage is determined according to the quadrature axis inductance, the direct axis inductance and the permanent magnet flux linkage, and the latest corresponding relation is compared with the preset corresponding relation contained in the control model. When the latest correspondence determined based on the actual intrinsic parameters is different from the predetermined correspondence, the predetermined correspondence is replaced with the latest correspondence. For example, in the operation process of the motor, the quadrature axis flux linkage and the direct axis flux linkage corresponding to the current quadrature axis current and the current direct axis current may be calculated based on the estimated quadrature axis inductance, the estimated direct axis inductance, and the estimated permanent magnet flux linkage, and compared with the quadrature axis flux linkage and the direct axis flux linkage corresponding to the current quadrature axis current and the current direct axis current in the predetermined correspondence relationship, if the quadrature axis flux linkage and the direct axis flux linkage are different, it is indicated that the latest correspondence relationship determined based on the actual intrinsic parameter is different from the predetermined correspondence relationship. Therefore, on one hand, the calculated quadrature axis magnetic flux linkage and the calculated direct axis magnetic flux linkage can be directly used for replacing the corresponding quadrature axis magnetic flux linkage and the corresponding direct axis magnetic flux linkage in the preset corresponding relation; on the other hand, the quadrature-axis current and the direct-axis current corresponding to different quadrature-axis magnetic chains and different direct-axis magnetic chains can be re-determined based on the calculated quadrature-axis inductance, direct-axis inductance and permanent magnet magnetic chain to form the latest corresponding relationship, and the preset corresponding relationship is replaced by the latest corresponding relationship. Therefore, the latest corresponding relation can be adopted to replace the preset corresponding relation through the two modes, and the correction of the control model is further realized.

Wherein the correspondence of the direct-axis current to the direct-axis flux linkage may be determined based on the following formula (4):

the correspondence of the quadrature axis current to the quadrature axis flux linkage may be determined based on the following equation (5):

in the formula, i_dIs a direct axis current, i_qIs quadrature axis current;is an estimate of the direct axis flux linkage, i.e. the direct axis current i_dA corresponding direct axis flux linkage;is an estimate of quadrature axis flux linkage, i.e. quadrature axis current i_qAnd (4) corresponding quadrature axis magnetic linkage.As an estimate of the flux linkage of the permanent magnet,is an estimate of the direct-axis inductance,is an estimate of quadrature inductance.

Further, the latest corresponding relation between the quadrature axis current and the direct axis current and the torque and the rotating speed can be determined according to the calculated quadrature axis inductance, the calculated direct axis inductance and the calculated permanent magnet flux linkage, and the latest corresponding relation is compared with the preset corresponding relation contained in the control model. When the latest correspondence determined based on the actual intrinsic parameters is different from the predetermined correspondence, the predetermined correspondence is replaced with the latest correspondence. For example, during the operation of the motor, the torque corresponding to the current quadrature-axis current and the current direct-axis current may be calculated based on the estimated quadrature-axis inductance, the estimated direct-axis inductance, and the estimated permanent magnet flux linkage, the rotational speed corresponding to the current quadrature-axis current and the current direct-axis current may be detected, and then the torque and the rotational speed corresponding to the current quadrature-axis current and the current direct-axis current in the predetermined correspondence may be compared, and if the torque and the rotational speed are different from each other, it may be indicated that the latest correspondence determined based on the actual intrinsic parameter is different from the predetermined correspondence. Therefore, the quadrature-axis current and the direct-axis current corresponding to different torques and rotating speeds can be redetermined according to the motor control strategy based on the calculated quadrature-axis inductance, direct-axis inductance and permanent magnet flux linkage to form the latest corresponding relation, and the preset corresponding relation is replaced by the latest corresponding relation. The motor control strategy may be predetermined according to motor control requirements, for example, the motor control strategy may be a maximum torque to current ratio control.

Wherein the correspondence relationship between the quadrature axis current and the direct axis current and the torque may be determined based on the following formula (6):

in the formula, i_dIs a direct axis current, i_qIs quadrature axis current;as an estimate of the torque, i.e. the direct-axis current i_dAnd quadrature axis current i_qA corresponding torque; n is_pIs the number of the magnetic pole pairs of the motor,as an estimate of the flux linkage of the permanent magnet,is an estimate of the direct-axis inductance,is an estimate of quadrature inductance.

Fig. 2 is a flowchart illustrating a control method for an electric motor according to an alternative embodiment of the present invention. In an alternative embodiment of the present invention, as shown in fig. 2, during the operation of the motor, the direct-axis current i of the motor at the current speed n and torque Te can be obtained_dQuadrature axis current i_qD.d. voltage u_dAnd quadrature axis voltage u_qAnd detecting the angular velocity omega of the motor_rThen according to the direct axis current i_dQuadrature axis current i_qD.d. voltage u_dQuadrature axis voltage u_qAnd angular velocity ω_rCalculating the direct-axis inductance L of the motor at the current rotating speed n and the current torque Te_dQuadrature axis inductor L_qAnd permanent magnet flux linkage psi_f. Then, the direct-axis inductance L is obtained through calculation_dQuadrature axis inductor L_qAnd permanent magnet flux linkage psi_fCombined with the current direct axis current i_dAnd quadrature axis current i_qCalculating the direct-axis flux linkage F of the motor under the current rotating speed n and the current torque Te together_dAnd quadrature axis linkage F_q. Then, the current direct axis current i is determined according to the preset corresponding relation in the preset control model_dAnd quadrature axis current i_qCorresponding direct axis flux linkage F_dAnd quadrature axis linkage F_qAnd determining the direct axis flux linkage F obtained by calculation_dAnd quadrature axis linkage F_qWith direct-axis flux linkage F determined on the basis of predetermined correspondence_dAnd quadrature axis linkage F_qWhether or not they are the same.If the two are the same, no processing is carried out; if different, the direct axis flux linkage F is obtained through calculation_dAnd quadrature axis linkage F_qCovering and replacing the corresponding direct axis flux linkage F in the predetermined correspondence_dAnd quadrature axis linkage F_q. Further, the current direct axis current i can be determined according to_dQuadrature axis current i_qStraight axis inductor L_dQuadrature axis inductor L_qAnd permanent magnet flux linkage psi_fCalculating the current torque Te and detecting the current rotation speed n of the motor, and then determining the calculated torque Te and the detected rotation speed n and the current direct-axis current i determined according to the preset corresponding relation_dAnd quadrature axis current i_qWhether the corresponding torque Te and the corresponding rotational speed n are the same. If the two values are the same, no processing is carried out, and if the two values are different, the direct axis inductance L obtained based on calculation is used_dQuadrature axis inductor L_qAnd permanent magnet flux linkage psi_fRe-determining different torque Te and quadrature axis current i corresponding to rotating speed n according to motor control strategy_qAnd a direct axis current i_dTo form the latest correspondence and replace the predetermined correspondence with the latest correspondence. The calculation processes can be performed locally on the device (such as a new energy automobile) where the motor is located, or can be transmitted to a remote server for online calculation. The specific calculation mode can adopt a table look-up estimation and can also carry out calculation based on a corresponding formula. In addition, the preset control model for regularly or real-timely correcting the motor can be selected according to actual needs.

In addition, the predetermined control model can be corrected and the direct-axis inductance L can be obtained based on calculation_dQuadrature axis inductor L_qAnd permanent magnet flux linkage psi_fCombined with the current direct axis current i_dAnd quadrature axis current i_qThe current actual torque of the electric machine is determined and it is determined whether the actual torque equals a target torque of the electric machine, which may be allocated to the electric machine, for example, by a vehicle control unit of a vehicle in which the electric machine is located. If the actual torque of the motor is equal to the target torque, no processing is performed; if the actual torque of the Motor is relatively small, a Motor Control Unit (MCU) controls the Motor to increase the torque; if the actual torque of the motor is relatively large,the motor controller controls the motor to reduce the torque. And repeating the steps until the actual torque of the motor is equal to the target torque.

Fig. 3 is a block diagram schematically illustrating a control apparatus for a motor according to an embodiment of the present invention. As shown in fig. 3, an embodiment of the present invention also provides a control apparatus for a motor, which may include: a memory 12, a processor 11 and a computer program stored on the memory 12 and executable on the processor 11, the processor 11 executing the computer program to implement the above-described control method for the motor. In some alternative embodiments, the control device may be an intelligent motor controller, so that the motor may be controlled directly, and in other alternative embodiments, the control device may control the motor indirectly through the motor controller.

Fig. 4 is a block diagram schematically illustrating an automobile according to an embodiment of the present invention. As shown in fig. 4, the embodiment of the present invention also provides an automobile which may include a motor 20 and the control device 10 for a motor described above. The motor 20 may be provided with a rotation speed sensor for detecting a rotation speed of the motor, and the control device 10 may detect the rotation speed of the motor 20 through the rotation speed sensor. The vehicle may be a new energy vehicle or the like using a motor, and more specifically, the vehicle may be a pure electric vehicle or a hybrid vehicle.

Embodiments also provide a machine-readable storage medium having stored thereon instructions for enabling a processor to execute the above-described control method for a motor when executed by the processor.

While the invention has been described in detail with reference to the drawings, the invention is not limited to the details of the embodiments, and various simple modifications can be made within the technical spirit of the embodiments of the invention.

It should be noted that the various features described in the above embodiments may be combined in any suitable manner without departing from the scope of the invention. In order to avoid unnecessary repetition, the embodiments of the present invention will not be described separately for the various possible combinations.

Those skilled in the art will appreciate that all or part of the steps in the method according to the above embodiments may be implemented by a program, which is stored in a storage medium and includes instructions for causing a single chip, a chip, or a processor (processor) to execute all or part of the steps in the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.

In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the idea of the embodiments of the present invention.