Motor field weakening control method, device and equipment and storage medium

Abstract

The invention provides a motor flux-weakening control method, device and equipment and a storage medium, and relates to the technical field of motor control, and the method comprises the steps: judging whether a current motor is in a deep flux-weakening region or not through the d-axis component and q-axis component of the current current and voltage of the motor; when the motor is judged to be in a deep flux weakening area, determining a target combined boundary value of a d-axis current and a q-axis current which are currently required by combining a theoretical q-axis voltage value which is set to be zero with a flux linkage, direct current inductance, alternating current inductance, a target rotating speed and an execution torque of the motor; and an actual combined boundary value obtained according to the current actual d-axis current and q-axis current is compared with a target combined boundary value, and then a preset parameter comparison table is combined to output a target current and a target torque required by the current motor, so that the motor is controlled more accurately in the deep flux weakening control region. In addition, the boundary value of the d-axis current and the q-axis current is adopted for field weakening control, so that the rotating speed of the motor can be increased to the maximum.

Description

Technical Field

[0001] The present application relates to the field of motor control technology, and in particular to a motor weak magnetic control method, device, equipment and storage medium. Background Art

[0002] In the prior art, when the motor is subjected to weak magnetic field control, the relationship between the d-axis current, the q-axis current and the electromagnetic torque is usually used to calculate the electromagnetic torque by combining the experimental data obtained through bench test with the theoretical formula analysis. However, there is a certain deviation between the electromagnetic torque obtained in the above manner and the measured torque. When the motor speed reaches above the rated speed value, that is, when entering deep weak magnetic field control, the deviation will be significantly aggravated and amplified, which can easily lead to reduced output control accuracy and reduced motor system efficiency. Summary of the invention

[0003] The main purpose of this application is to provide a motor weak magnetic control method, device, equipment and storage medium, aiming to solve the technical problem of how to more accurately perform deep weak magnetic control on the motor.

[0004] To achieve the above object, the present application provides a motor weak magnetic field control method, the motor weak magnetic field control method comprising the following steps:

[0005] Based on the current real-time speed and execution torque of the motor, the corresponding d-axis current value, q-axis current value, d-axis voltage value and q-axis voltage value are obtained in real time;

[0006] Determine the control zone in which the motor is currently located based on the d-axis current value, the q-axis current value, the d-axis voltage value, the q-axis voltage value, the maximum allowable bus voltage value, and the maximum current vector modulus value;

[0007] When the control area is a deep magnetic weakening control area, the theoretical q-axis voltage value is set to zero, and based on the real-time motor flux, DC inductance value, AC inductance value, target speed and the execution torque of the motor, the target dq-axis current combination boundary value is obtained;

[0008] Based on the target dq-axis current combination boundary value, the d-axis current value, the q-axis current value and a preset parameter comparison table, the target current and the target torque are output to the motor so that the motor performs deep magnetic weakening control.

[0009] In one embodiment, the step of determining the control zone in which the motor is currently located based on the d-axis current value, the q-axis current value, the d-axis voltage value, the q-axis voltage value, the maximum allowable bus voltage value, and the maximum current vector modulus value comprises:

[0010] Acquire a voltage vector modulus value based on an absolute value of the d-axis voltage value and an absolute value of the q-axis voltage value, and acquire a current vector modulus value based on an absolute value of the d-axis current value and an absolute value of the q-axis current value;

[0011] The control zone in which the motor is currently located is determined based on the voltage vector magnitude, the maximum allowable bus voltage value, the current vector magnitude and the maximum current vector magnitude.

[0012] In one embodiment, before the step of determining the control zone in which the motor is currently located based on the voltage vector modulus, the maximum allowable bus voltage value, the current vector modulus and the maximum current vector modulus, the step further includes:

[0013] Based on the real-time rotation speed and the execution torque, the currently corresponding maximum current vector modulus value is determined.

[0014] In one embodiment, when the control zone is a deep magnetic weakening control zone, the theoretical q-axis voltage value is set to zero, and based on the real-time motor flux, DC inductance value, AC inductance value, target speed and the execution torque of the motor, the step of obtaining the target dq-axis current combination boundary value includes:

[0015] When the control area is the deep magnetic weakening control area, the theoretical q-axis voltage value is set to zero, and a theoretical d-axis current boundary value is determined based on the real-time motor flux, the DC inductance value and the target speed;

[0016] Determining a theoretical q-axis current boundary value based on the theoretical d-axis current boundary value, the target speed, the execution torque, the real-time motor flux, the DC inductance value, and the AC inductance value;

[0017] Based on the theoretical d-axis current boundary value and the theoretical q-axis current boundary value, the target dq-axis current combination boundary value is acquired.

[0018] In one embodiment, the step of outputting the target current and the target torque to the motor based on the target dq axis current combination boundary value, the d axis current value, the q axis current value and the preset parameter comparison table includes:

[0019] Determining an actual dq axis current combination boundary value based on the d axis current value and the q axis current value;

[0020] When the actual dq axis current combination boundary value exceeds the target dq axis current combination boundary value, based on the target dq axis current combination boundary value and the preset parameter comparison table, output the corresponding target current and the target torque to the motor;

[0021] Or, when the actual dq axis current combination boundary value does not exceed the target dq axis current combination boundary value, based on the actual dq axis current combination boundary value and the preset parameter comparison table, the corresponding target current and the target torque are output to the motor.

[0022] In one embodiment, after the step of determining the actual dq-axis current combination boundary value based on the d-axis current value and the q-axis current value, the method further includes:

[0023] When the actual dq-axis current combination boundary value is integrally saturated, acquiring the current corresponding real-time voltage vector modulus value based on the d-axis voltage value and the q-axis voltage value;

[0024] The q-axis voltage value is switched to zero, and the d-axis current value is gradually increased and the absolute value of the d-axis current value is gradually decreased based on the preset step size until the real-time voltage vector modulus reaches the preset voltage value, so that the dq-axis current combination boundary value integral is desaturated.

[0025] In one embodiment, when the control zone is a deep magnetic weakening control zone, before the step of setting the theoretical q-axis voltage value to zero and obtaining the target dq-axis current combination boundary value based on the real-time motor flux, DC inductance, AC inductance, target speed and the execution torque of the motor, the step further includes:

[0026] Obtaining the working environment temperature of the motor, the number of motor poles, the preset mechanical speed in a no-load state, and the corresponding no-load back electromotive force;

[0027] Obtaining a theoretical motor flux based on the preset mechanical speed, the no-load back electromotive force, and the number of motor pole pairs;

[0028] Determining a flux compensation value based on the working environment temperature and a preset temperature compensation comparison table;

[0029] The real-time motor flux is obtained based on the flux compensation value and the theoretical motor flux.

[0030] In addition, to achieve the above-mentioned purpose, the present application also provides a motor weak magnetic field control device, the motor weak magnetic field control device comprising:

[0031] An electrical parameter acquisition module, used to acquire the corresponding d-axis current value, q-axis current value, d-axis voltage value and q-axis voltage value in real time based on the current real-time speed and execution torque of the motor;

[0032] a control zone determination module, configured to determine the control zone in which the motor is currently located based on the d-axis current value, the q-axis current value, the d-axis voltage value, the q-axis voltage value, the maximum allowable bus voltage value, and the maximum current vector modulus value;

[0033] a target parameter acquisition module, for setting the theoretical q-axis voltage value to zero when the control area is a deep magnetic weakening control area, and acquiring a target dq-axis current combination boundary value based on the real-time motor flux, DC inductance value, AC inductance value, target speed and execution torque of the motor;

[0034] A control parameter output module is used to output the target current and target torque to the motor based on the target dq axis current combination boundary value, the d axis current value, the q axis current value and a preset parameter comparison table, so that the motor performs deep magnetic weakening control.

[0035] In addition, to achieve the above-mentioned purpose, the present application also provides a motor weak magnetic field control device, which includes: a memory, a processor, and a motor weak magnetic field control program stored in the memory and executable on the processor, and the motor weak magnetic field control program is configured to implement the steps of the motor weak magnetic field control method as described above.

[0036] In addition, to achieve the above-mentioned purpose, the present application also provides a storage medium, which is a computer-readable storage medium, and a motor weak magnetic field control program is stored on the computer-readable storage medium. When the motor weak magnetic field control program is executed by the processor, the steps of the motor weak magnetic field control method described above are implemented.

[0037] The present application provides a motor weakening magnetic control method, device, equipment and storage medium, the steps of the motor weakening magnetic control method include: based on the current real-time speed and execution torque of the motor, real-time acquisition of the corresponding d-axis current value, q-axis current value, d-axis voltage value and q-axis voltage value; based on the d-axis current value, the q-axis current value, the d-axis voltage value, the q-axis voltage value, the maximum allowable bus voltage value and the maximum current vector modulus value, determine the control area where the motor is currently located; when the control area is a deep weakening magnetic control area, set the theoretical q-axis voltage value to zero, and based on the real-time motor flux, DC inductance value, AC inductance value, target speed and the execution torque of the motor, acquire the target dq-axis current combination boundary value; based on the target dq-axis current combination boundary value, the d-axis current value and the q-axis current value and a preset parameter comparison table, output the target current and target torque to the motor, so that the motor performs deep weakening magnetic control.

[0038] The d-axis component and q-axis component of the current current and voltage of the motor are used to determine whether the current motor is in a deep magnetic weakening area. When determining that the motor is in a deep magnetic weakening area, the target combined boundary value of the d-axis current and q-axis current currently required is determined by combining the magnetic flux, DC inductance, AC inductance, target speed and execution torque of the motor with the theoretical q-axis voltage value set to zero, and then the actual combined boundary value obtained according to the current actual d-axis current and q-axis current is compared with the target combined boundary value, and then combined with the preset parameter comparison table, the target current and target torque required by the current motor are output, so as to achieve more accurate control of the motor in the deep magnetic weakening control area. In addition, since the boundary values ​​of the d-axis current and the q-axis current are used for magnetic weakening control, the motor speed can also be increased to the maximum. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0040] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0041] Figure 1 A schematic diagram of a flow chart provided for the first embodiment of the motor weak magnetic field control method of the present application;

[0042] Figure 2 A flow chart of the second embodiment of the motor weak magnetic field control method of the present application;

[0043] Figure 3 A schematic diagram of a flow chart provided for Embodiment 3 of the motor weak magnetic field control method of the present application;

[0044] Figure 4 This is a schematic diagram of the module structure of the motor weak magnetic field control device according to an embodiment of the present application;

[0045] Figure 5 This is a schematic diagram of the structure of the motor weak magnetic control device according to an embodiment of the present application.

[0046] The purpose, features and advantages of this application will be further described in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0047] It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the present application and are not used to limit the present application.

[0048] In order to better understand the technical solution of the present application, a detailed description will be given below in conjunction with the accompanying drawings and specific implementation methods.

[0049] The main solution of the present application is: based on the current real-time speed and execution torque of the motor, the corresponding d-axis current value, q-axis current value, d-axis voltage value and q-axis voltage value are obtained in real time; based on the d-axis current value, the q-axis current value, the d-axis voltage value, the q-axis voltage value, the maximum allowable bus voltage value and the maximum current vector modulus value, the control zone in which the motor is currently located is determined; when the control zone is a deep magnetic weakening control zone, the theoretical q-axis voltage value is set to zero, and based on the real-time motor magnetic flux, DC inductance value, AC inductance value, target speed and the execution torque of the motor, the target dq-axis current combination boundary value is obtained; based on the target dq-axis current combination boundary value, the d-axis current value and the q-axis current value and the preset parameter comparison table, the target current and target torque are output to the motor to perform deep magnetic weakening control on the motor.

[0050] At present, when weak magnetic field control is performed on a motor, the relationship between the d-axis current, the q-axis current and the electromagnetic torque is usually used to calculate the electromagnetic torque by combining the experimental data obtained through bench test with the theoretical formula analysis. However, there is a certain deviation between the electromagnetic torque obtained in the above way and the measured torque. When the motor speed reaches a relatively high rated value, that is, when entering deep weak magnetic field control, the deviation will be significantly aggravated, which can easily lead to reduced output control accuracy and reduced motor system efficiency. Therefore, how to more accurately perform deep weak magnetic field control on the motor is a problem that needs to be solved urgently.

[0051] This application determines whether the current motor is in a deep magnetic weakening zone by the d-axis component and q-axis component of the current current and voltage of the motor. When determining that the motor is in a deep magnetic weakening zone, the target combined boundary value of the d-axis current and q-axis current currently required is determined by combining the magnetic flux, DC inductance, AC inductance, target speed and execution torque of the motor with the theoretical q-axis voltage value set to zero, and then the actual combined boundary value obtained according to the current actual d-axis current and q-axis current is compared with the target combined boundary value, and then combined with the preset parameter comparison table, the target current and target torque required by the current motor are output, so as to achieve more accurate control of the motor in the deep magnetic weakening control zone. In addition, since the boundary values ​​of the d-axis current and the q-axis current are used for magnetic weakening control, the motor speed can also be increased to the maximum.

[0052] It should be noted that the execution subject of this embodiment may be a motor weak magnetic field control device, or a motor weak magnetic field control device with data processing, network communication and program running functions, etc., and this embodiment does not specifically limit this. The following takes the motor weak magnetic field control device as an example to illustrate this embodiment and the following embodiments.

[0053] Based on this, the present application proposes a motor weak magnetic control method of the first embodiment, please refer to Figure 1 , the motor weak magnetic field control method comprises steps S10-S40:

[0054] Step S10, based on the current real-time speed and execution torque of the motor, obtaining the corresponding d-axis current value, q-axis current value, d-axis voltage value and q-axis voltage value in real time;

[0055] It should be understood that in this embodiment, the motor can be a permanent magnet synchronous motor, the d-axis current value refers to the DC component of the current used to control the motor, the q-axis current value refers to the AC component of the current used to control the motor, the d-axis voltage value refers to the DC component of the voltage used to control the motor, and the q-axis voltage value refers to the AC component of the voltage used to control the motor.

[0056] It is easy to understand that in this embodiment, the larger the synthetic vector of the d-axis current value and the q-axis current value, the higher the motor speed will be, and the greater the torque generated will be, and the corresponding d-axis voltage value and q-axis voltage value adjusted by the current loop will also increase. Therefore, the d-axis current value, q-axis current value, d-axis voltage value, and q-axis voltage value can be obtained in sequence through the current real-time speed and execution torque of the motor.

[0057] Step S20, determining the control zone in which the motor is currently located based on the d-axis current value, the q-axis current value, the d-axis voltage value, the q-axis voltage value, the maximum allowable bus voltage value, and the maximum current vector modulus value;

[0058] It should be noted that, in this embodiment, the maximum allowable bus voltage value refers to the maximum safe value of the voltage loaded to the three-phase terminals of the motor after adjustment by the motor controller. The maximum current vector modulus value refers to the maximum value of the current vector modulus value synthesized by the d-axis current and the q-axis current in their respective corresponding normal current change intervals.

[0059] It is easy to understand that in this embodiment, the currently acquired d-axis voltage value and q-axis voltage value can be compared with the corresponding maximum allowable bus voltage value, and then the current d-axis current value and q-axis current value can be compared with the maximum current vector modulus value, so as to determine whether the control area where the motor is currently located is a normal weak magnetic control area or a deep weak magnetic control area.

[0060] Step S30, when the control area is a deep magnetic weakening control area, setting the theoretical q-axis voltage value to zero, and acquiring a target dq-axis current combination boundary value based on the real-time motor flux, DC inductance value, AC inductance value, target speed and execution torque of the motor;

[0061] It should be noted that, in this embodiment, the theoretical q-axis voltage value refers to a set value used to calculate various theoretical parameters, which is used to represent a theoretical specific q-axis voltage value. The real-time motor flux, DC inductance value, and AC inductance value are parameters unique to the motor after it is assembled, which are generally fixed values ​​and are known quantities. The target speed refers to the speed that the motor needs to reach at the current setting. There is a corresponding relationship between the motor's speed, torque, flux, DC inductance, and AC inductance and the d-axis current and q-axis current, and the d-axis current and q-axis current have a certain relationship with the d-axis voltage and q-axis voltage. At the same time, the d-axis voltage and the q-axis voltage also have a certain relationship, so the corresponding theoretical parameters of the d-axis current and the q-axis current can be obtained through the theoretical q-axis voltage.

[0062] It is easy to understand that in this embodiment, if the motor is currently in the deep magnetic weakening control area, the theoretical d-axis current value and the theoretical q-axis current value can be calculated by using the theoretical q-axis voltage value, combined with the real-time motor flux, DC inductance value, AC inductance value, target speed and execution torque of the motor. Since there is a corresponding relationship between the change trend of the theoretical d-axis current value and the theoretical q-axis current value and the change trend of the theoretical q-axis voltage value and the theoretical d-axis voltage value, when the theoretical q-axis voltage value takes the limit boundary value (zero), the obtained theoretical d-axis current value and the theoretical q-axis current value are both corresponding boundary values. And by using the boundary value of the theoretical d-axis current value corresponding to the target speed and the boundary value of the theoretical q-axis current value, the target dq-axis current combination boundary value corresponding to the target speed can be obtained.

[0063] Step S40, based on the target dq axis current combination boundary value, the d axis current value, the q axis current value and a preset parameter comparison table, output the target current and target torque to the motor so that the motor performs deep magnetic weakening control.

[0064] It is easy to understand that the current d-axis current value and q-axis current value can be compared with the target dq-axis current combination boundary value, and the most appropriate boundary value parameters can be selected according to the comparison results, and substituted into the preset parameter comparison table for table lookup, so as to output the corresponding target current and target torque to the motor according to the table lookup results, so that the motor can be more accurately deeply weakened. In addition, since the boundary values ​​of current and voltage corresponding to the current motor speed can always be obtained to perform deep weakening control on the motor, it can be ensured that the bus electrical parameters of the motor are also within the boundary values ​​within the allowable range, so the adjustable range of the motor speed will be further increased.

[0065] The present application provides a motor weakening magnetic control method, the steps of the motor weakening magnetic control method include: based on the current real-time speed and execution torque of the motor, real-time acquisition of corresponding d-axis current value, q-axis current value, d-axis voltage value and q-axis voltage value; based on the d-axis current value, the q-axis current value, the d-axis voltage value, the q-axis voltage value, the maximum allowable bus voltage value and the maximum current vector modulus value, determine the control area where the motor is currently located; when the control area is a deep weakening magnetic control area, set the theoretical q-axis voltage value to zero, and based on the real-time motor flux, DC inductance value, AC inductance value, target speed and the execution torque of the motor, obtain the target dq-axis current combination boundary value; based on the target dq-axis current combination boundary value, the d-axis current value and the q-axis current value and the preset parameter comparison table, output the target current and target torque to the motor, so that the motor performs deep weakening magnetic control. Through the d-axis component and q-axis component of the current and voltage of the motor, it is judged whether the current motor is in the deep weakening magnetic area. When it is determined that the motor is in a deep magnetic weakening area, the target combined boundary value of the d-axis current and q-axis current currently required is determined by combining the magnetic flux, DC inductance, AC inductance, target speed and execution torque of the motor with the theoretical q-axis voltage value set to zero, and then the actual combined boundary value obtained based on the current actual d-axis current and q-axis current is compared with the target combined boundary value and combined with the preset parameter comparison table to output the target current and target torque required by the current motor, thereby achieving more accurate control of the motor in the deep magnetic weakening control area. In addition, since the boundary values ​​of the d-axis current and the q-axis current are used for magnetic weakening control, the motor speed can also be increased to the maximum.

[0066] Based on the first embodiment of the present application, in the second embodiment of the present application, the same or similar contents as those in the above-mentioned embodiment 1 can refer to the above introduction, and will not be repeated later. Figure 2 The step of determining the control zone in which the motor is currently located based on the d-axis current value, the q-axis current value, the d-axis voltage value, the q-axis voltage value, the maximum allowable bus voltage value, and the maximum current vector modulus value comprises:

[0067] Step S21, obtaining a voltage vector modulus value based on the absolute value of the d-axis voltage value and the absolute value of the q-axis voltage value, and obtaining a current vector modulus value based on the absolute value of the d-axis current value and the absolute value of the q-axis current value;

[0068] Step S22, determining the control zone in which the motor is currently located based on the voltage vector modulus, the maximum allowable bus voltage value, the current vector modulus and the maximum current vector modulus.

[0069] It should be noted that, in this embodiment, the voltage vector modulus is the modulus or absolute value of the vector superposition value of the d-axis voltage value and the q-axis voltage value, which should not exceed the preset maximum allowable bus voltage value, and its calculation formula is:

[0070]

[0071] Among them, U s is the voltage vector modulus, U d is the d-axis voltage value, U q is the q-axis voltage value, U dc is the maximum bus voltage, It is the maximum allowable bus voltage value (or the maximum voltage value that the bus can provide).

[0072] Correspondingly, the current vector modulus is the modulus or absolute value of the vector superposition value of the d-axis current value and the q-axis current value, which should not exceed the preset maximum current vector value. The calculation formula is:

[0073]

[0074] Among them, I s is the current vector modulus, I d is the d-axis current value, I q is the q-axis current value, I smax is the maximum current vector value.

[0075] It is easy to understand that in this embodiment, if the voltage vector modulus of the voltage vector synthesized by the d-axis voltage and the q-axis voltage exceeds the maximum allowable bus voltage value, the absolute value of the d-axis current value and the absolute value of the q-axis current value are also limited by the voltage vector and no longer increase. If the current vector modulus of the current vector synthesized by the d-axis current and the q-axis current at this time does not reach the maximum current vector value, it can be considered that the current motor is in the deep magnetic weakening control area, otherwise the motor is in the normal magnetic weakening control area.

[0076] Further, in this embodiment, before the step of determining the control zone in which the motor is currently located based on the voltage vector modulus, the maximum allowable bus voltage value, the current vector modulus and the maximum current vector modulus, the step further includes:

[0077] Step S201, determining the current corresponding maximum current vector modulus value based on the real-time rotation speed and the execution torque.

[0078] It is easy to understand that as the motor speed increases and the execution torque increases, the maximum current vector modulus will gradually decrease. There is a corresponding relationship between the three. Therefore, the maximum current vector modulus in the current situation can be determined by the current corresponding real-time speed and execution torque.

[0079] Further, in this embodiment, when the control area is a deep magnetic weakening control area, the theoretical q-axis voltage value is set to zero, and based on the real-time motor flux, DC inductance value, AC inductance value, target speed and the execution torque of the motor, the step of obtaining the target dq-axis current combination boundary value includes:

[0080] Step S31, when the control area is the deep magnetic weakening control area, setting the theoretical q-axis voltage value to zero, and determining a theoretical d-axis current boundary value based on the real-time motor flux, the DC inductance value and the target speed;

[0081] Step S32, determining a theoretical q-axis current boundary value based on the theoretical d-axis current boundary value, the target speed, the execution torque, the real-time motor flux, the DC inductance value, and the AC inductance value;

[0082] It should be noted that, in this embodiment, if the control area of ​​the motor is in the deep magnetic weakening control area, the calculation formulas of the d-axis voltage value and the q-axis voltage value are as follows:

[0083]

[0084] Among them, U d is the d-axis voltage value, U q is the q-axis voltage value, I d is the d-axis current value, I q is the q-axis current value, R is the stator resistance, w e is the angular velocity of the motor (which can be converted from the target speed of the motor), ψ f is the real-time motor flux, L d is the DC inductance value of the d-axis, L q is the AC inductance value of the q-axis.

[0085] It should be understood that after the motor is manufactured, under certain circumstances, the parameters such as flux and inductance are determined, that is, the real-time motor flux, DC inductance, and AC inductance are all known fixed values. When the motor is running in a stable condition, the stator resistance is very small and the differential of the current is also very small and can be ignored, so the simplified formula is as follows:

[0086] U d =-w e *L q *I q ;

[0087] U q =w e *(L d *I d +ψ f );

[0088] At this time, the theoretical q-axis voltage value is set to zero as the limit value condition, and the d-axis voltage value, q-axis voltage value and maximum allowable bus voltage value mentioned above are also used as the limit value conditions:

[0089]

[0090] Substituting into the above simplified formula, the theoretical d-axis current value corresponding to the target speed can be obtained. Since the current theoretical q-axis voltage value is set to the limit boundary value (zero), the theoretical d-axis current value obtained under this condition is the theoretical d-axis current boundary value.

[0091] The motor's execution torque, real-time motor flux, DC inductance, AC inductance, d-axis current, and q-axis current have the following relationship at a specific speed:

[0092]

[0093] Among them, T e is the actuating torque, p n is the number of pole pairs of the motor (a known quantity), I d is the d-axis current value, I q is the q-axis current value, ψ f is the real-time motor flux, L d is the DC inductance value of the d-axis, L q is the AC inductance value of the q-axis.

[0094] Therefore, the theoretical d-axis current boundary value can be substituted into the corresponding theoretical q-axis current boundary value.

[0095] Step S33: acquiring the target dq-axis current combination boundary value based on the theoretical d-axis current boundary value and the theoretical q-axis current boundary value.

[0096] It is easy to understand that the target dq axis current combination boundary value described in this article can be obtained by the ratio of the theoretical d axis current boundary value to the theoretical q axis current boundary value.

[0097] Based on the first embodiment and / or the second embodiment of the present application, in the third embodiment of the present application, the same or similar contents as those of the above-mentioned first and second embodiments can refer to the above introduction, and will not be repeated later. Figure 3 The step of outputting the target current and the target torque to the motor based on the target dq axis current combination boundary value, the d axis current value, the q axis current value and the preset parameter comparison table includes:

[0098] Step S41, determining an actual dq axis current combination boundary value based on the d axis current value and the q axis current value;

[0099] It is easy to understand that in this embodiment, the actual dq axis current combination boundary value corresponding to the current can be obtained by the ratio of the currently obtained d axis current value to the q axis current value.

[0100] Step S42, when the actual dq axis current combination boundary value exceeds the target dq axis current combination boundary value, based on the target dq axis current combination boundary value and the preset parameter comparison table, outputting the corresponding target current and the target torque to the motor;

[0101] Step S43, or, when the actual dq axis current combination boundary value does not exceed the target dq axis current combination boundary value, based on the actual dq axis current combination boundary value and the preset parameter comparison table, output the corresponding target current and the target torque to the motor.

[0102] It is easy to understand that in this embodiment, in order to ensure that the motor can work accurately and stably in the deep magnetic weakening control area, when the actual dq axis current combination boundary value at the current real-time speed is Exceeds the target dq axis current combination boundary value corresponding to the target speed When the maximum target dq axis current combination boundary value is used, As a parameter, the table is looked up, and the corresponding target current and target torque under the current situation are obtained in the preset parameter comparison table and output to the motor; when the actual dq axis current combination boundary value at the current real-time speed The target dq axis current combination boundary value corresponding to the target speed is not exceeded When the actual dq axis current combination boundary value at the real speed is used A table is looked up as a parameter, and the target current and target torque corresponding to the current situation are obtained in the preset parameter comparison table and output to the motor.

[0103] Further, in this embodiment, after the step of determining the actual dq-axis current combination boundary value based on the d-axis current value and the q-axis current value, the step further includes:

[0104] Step S44, when the actual dq-axis current combination boundary value is integrally saturated, obtaining the current corresponding real-time voltage vector modulus value based on the d-axis voltage value and the q-axis voltage value;

[0105] Step S45, switching the q-axis voltage value to zero, and gradually increasing the d-axis current value and gradually decreasing the absolute value of the d-axis current value based on the preset step size, until the real-time voltage vector modulus reaches the preset voltage value, so that the dq-axis current combination boundary value integral is desaturated.

[0106] It should be noted that, in this embodiment, there is still an integral saturation situation in the actual dq axis current combination boundary value. In this case, a desaturation operation is required, otherwise an overcurrent fault may occur.

[0107] It is easy to understand that in this embodiment, the real-time voltage vector modulus can be obtained in real time through the d-axis voltage value and the q-axis voltage value. First, the q-axis voltage value is adjusted to zero to ensure that the motor system does not lose control and has torque output capability, and then the vector of the d-axis current value is changed along the positive direction at every preset step, that is, the d-axis current value gradually increases and the absolute value of the d-axis current value gradually decreases. As the process proceeds step by step, the real-time voltage vector modulus gradually increases until the real-time voltage vector modulus increases to the preset voltage value, so that the motor reaches the optimal working efficiency point, thereby completing the desaturation operation.

[0108] It is worth noting that, in this embodiment, the preset voltage value may be the maximum operating bus voltage value mentioned above.

[0109] Further, in this embodiment, when the control area is a deep magnetic weakening control area, the theoretical q-axis voltage value is set to zero, and based on the real-time motor flux, DC inductance value, AC inductance value, target speed and the execution torque of the motor, before the step of obtaining the target dq-axis current combination boundary value, it also includes:

[0110] Step S301, obtaining the working environment temperature of the motor, the number of motor pole pairs, the preset mechanical speed in a no-load state, and the corresponding no-load back electromotive force;

[0111] Step S302, obtaining a theoretical motor flux based on the preset mechanical speed, the no-load back electromotive force, and the number of motor pole pairs;

[0112] It should be noted that in this embodiment, the motor flux can be obtained through no-load back electromotive force, motor pole pair number and other parameters under a specific motor speed and a specific temperature environment. Therefore, the motor can be tested under no-load conditions to obtain the no-load back electromotive force of the motor, and the test speed is the preset mechanical speed. Combined with the fixed motor pole pair number of the motor, the motor flux at a specific motor speed can be obtained:

[0113]

[0114] Among them, ψ f0is the calculated motor flux, U0 is the no-load back electromotive force, n rpm is the preset mechanical speed, p n is the number of motor pole pairs.

[0115] It is worth noting that in this embodiment, the motor flux can be obtained at different preset mechanical speeds by adjusting the preset mechanical speed, and the no-load back electromotive force corresponding to each electrode flux value can be linearly fitted to obtain a back electromotive force linear fitting curve and obtain the corresponding linear coefficient α, and then the linear fitting curve is subtracted from the actual value to obtain a linear compensation coefficient β. Through the linear coefficient α, the linear compensation coefficient β, and the back electromotive force linear fitting curve, a theoretical no-load back electromotive force with higher accuracy in the temperature environment can be obtained, so that the theoretical motor flux can be more accurately obtained according to the above formula.

[0116] Step S303, determining a flux compensation value based on the working environment temperature and a preset temperature compensation comparison table;

[0117] Step S304: acquiring the real-time motor flux based on the flux compensation value and the theoretical motor flux.

[0118] It should be noted that the deviation values ​​between the theoretical motor flux corresponding to each common temperature range obtained in the test can be used as compensation values ​​in a list format, and a mapping relationship can be established between the compensation values ​​and the test environment temperature to obtain a preset temperature compensation comparison table.

[0119] It is easy to understand that when obtaining the current working environment temperature, the flux compensation value corresponding to the current working environment temperature can be directly obtained by reading the table, and then the calculated theoretical motor flux is compensated by the flux compensation value to obtain the real-time motor flux.

[0120] It is worth noting that in this embodiment, the temperature difference between the upper and lower limits of the temperature interval can be 10°C, that is, a single temperature interval can be 10-20°C, and the overall value range of common temperature intervals can be -40-120°C. The specific working environment temperature can adopt the motor oil temperature.

[0121] The present application also provides a motor weak magnetic control device, please refer to Figure 4 , the motor weak magnetic control device comprises:

[0122] The electric parameter acquisition module 10 is used to acquire the corresponding d-axis current value, q-axis current value, d-axis voltage value and q-axis voltage value in real time based on the current real-time speed and execution torque of the motor;

[0123] A control zone determination module 20, configured to determine the control zone in which the motor is currently located based on the d-axis current value, the q-axis current value, the d-axis voltage value, the q-axis voltage value, the maximum allowable bus voltage value, and the maximum current vector modulus value;

[0124] A target parameter acquisition module 30 is used to set the theoretical q-axis voltage value to zero when the control area is a deep magnetic weakening control area, and to acquire a target dq-axis current combination boundary value based on the real-time motor flux, DC inductance value, AC inductance value, target speed and execution torque of the motor;

[0125] The control parameter output module 40 is used to output the target current and target torque to the motor based on the target dq axis current combination boundary value, the d axis current value, the q axis current value and a preset parameter comparison table, so that the motor performs deep magnetic weakening control.

[0126] The motor weakening magnetic field control device provided in the embodiment of the present application adopts the motor weakening magnetic field control method in the above embodiment, which can solve the technical problem of how to more accurately perform deep weakening magnetic field control on the motor. Compared with the prior art, the beneficial effects of the motor weakening magnetic field control device provided in the embodiment of the present application are the same as the beneficial effects of the motor weakening magnetic field control method provided in the above embodiment, and other technical features in the motor weakening magnetic field control device are the same as the features disclosed in the above embodiment method, which will not be repeated here.

[0127] The present application provides a motor weak magnetic field control device, which includes: at least one processor; and a memory connected to the at least one processor in communication; wherein the memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the motor weak magnetic field control method in the above-mentioned embodiment one.

[0128] Reference below Figure 5 , which shows a schematic diagram of the structure of a motor weak magnetic field control device suitable for implementing the embodiment of the present application. The motor weak magnetic field control device in the embodiment of the present application may include but is not limited to a vehicle-mounted terminal or other fixed terminal. Figure 5 The motor weak magnetic control device shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0129] like Figure 5As shown, the motor weakening magnetic control device may include a processing device 1001 (such as a central processing unit, a graphics processor, etc.), which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM: Read Only Memory) 1002 or a program loaded from a storage device 1003 to a random access memory (RAM: Random Access Memory) 1004. In RAM1004, various programs and data required for the operation of the motor weakening magnetic control device are also stored. The processing device 1001, ROM1002 and RAM1004 are connected to each other through a bus 1005. An input / output (I / O) interface 1006 is also connected to the bus. Generally, the following systems can be connected to the I / O interface 1006: an input device 1007 including, for example, a touch screen, a touch pad, a keyboard, a mouse, an image sensor, a microphone, an accelerometer, a gyroscope, etc.; an output device 1008 including, for example, a liquid crystal display (LCD: Liquid Crystal Display), a speaker, a vibrator, etc.; a storage device 1003 including, for example, a magnetic tape, a hard disk, etc.; and a communication device 1009. The communication device 1009 can allow the motor weakening magnetic field control device to communicate with other devices wirelessly or by wire to exchange data. Although the motor weakening magnetic field control device with various systems is shown in the figure, it should be understood that it is not required to implement or have all the systems shown. More or fewer systems can be implemented or provided alternatively.

[0130] In particular, according to the embodiments disclosed in the present application, the process described above with reference to the flowchart can be implemented as a computer software program. For example, the embodiments disclosed in the present application include a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program includes a program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network through a communication device, or installed from a storage device 1003, or installed from a ROM 1002. When the computer program is executed by the processing device 1001, the above-mentioned functions defined in the method of the embodiment disclosed in the present application are executed.

[0131] The motor weak magnetic field control device provided by the present application adopts the motor weak magnetic field control method in the above embodiment, which can solve the technical problem of how to more accurately perform deep weak magnetic field control on the motor. Compared with the prior art, the beneficial effects of the motor weak magnetic field control device provided by the present application are the same as the beneficial effects of the motor weak magnetic field control method provided by the above embodiment, and other technical features in the motor weak magnetic field control device are the same as the features disclosed in the method of the previous embodiment, which will not be repeated here.

[0132] It should be understood that the various parts disclosed in this application can be implemented by hardware, software, firmware or a combination thereof. In the description of the above embodiments, specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0133] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0134] The present application provides a computer-readable storage medium having computer-readable program instructions (ie, computer programs) stored thereon, the computer-readable program instructions being used to execute the motor weakening magnetic field control method in the above-mentioned embodiment.

[0135] The computer-readable storage medium provided in the present application may be, for example, a USB flash drive, but is not limited to electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, systems or devices, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this embodiment, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, system or device. The program code contained on the computer-readable storage medium may be transmitted using any appropriate medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination of the above.

[0136] The computer-readable storage medium may be included in the motor weak magnetic field control device; or may exist independently without being assembled into the motor weak magnetic field control device.

[0137] The computer-readable storage medium carries one or more programs. When the one or more programs are executed by the motor weak magnetic control device, the motor weak magnetic control device: based on the current real-time speed and execution torque of the motor, obtains the corresponding d-axis current value, q-axis current value, d-axis voltage value and q-axis voltage value in real time; based on the d-axis current value, the q-axis current value, the d-axis voltage value, the q-axis voltage value, the maximum allowable bus voltage value and the maximum current vector modulus value, determines the control area where the motor is currently located; when the control area is a deep weak magnetic control area, sets the theoretical q-axis voltage value to zero, and obtains the target dq-axis current combination boundary value based on the real-time motor flux, DC inductance value, AC inductance value, target speed and the execution torque of the motor; based on the target dq-axis current combination boundary value, the d-axis current value and the q-axis current value and a preset parameter comparison table, outputs the target current and target torque to the motor so that the motor performs deep weak magnetic control.

[0138] Computer program code for performing the operations of the present application may be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0139] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present application. In this regard, each square box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two square boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0140] The modules involved in the embodiments described in this application may be implemented by software or hardware, wherein the name of the module does not constitute a limitation on the unit itself in some cases.

[0141] The readable storage medium provided in the present application is a computer-readable storage medium, which stores computer-readable program instructions (i.e., computer programs) for executing the above-mentioned motor weakening magnetic control method, and can solve the technical problem of how to more accurately perform deep weakening magnetic control on the motor. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided in the present application are the same as the beneficial effects of the motor weakening magnetic control method provided in the above-mentioned embodiment, and will not be repeated here.

[0142] The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent processing scope of the present application.

Claims

1. A motor weak magnetic field control method, characterized in that: The motor weak magnetic field control method comprises the following steps: Based on the current real-time speed and execution torque of the motor, the corresponding d-axis current value, q-axis current value, d-axis voltage value and q-axis voltage value are obtained in real time; Determine the control zone in which the motor is currently located based on the d-axis current value, the q-axis current value, the d-axis voltage value, the q-axis voltage value, the maximum allowable bus voltage value, and the maximum current vector modulus value; When the control area is a deep magnetic weakening control area, the theoretical q-axis voltage value is set to zero, and based on the real-time motor flux, DC inductance value, AC inductance value, target speed and the execution torque of the motor, the target dq-axis current combination boundary value is obtained; Based on the target dq-axis current combination boundary value, the d-axis current value, the q-axis current value and a preset parameter comparison table, the target current and the target torque are output to the motor so that the motor performs deep magnetic weakening control.

2. The motor weak magnetic field control method according to claim 1, characterized in that: The step of determining the control zone in which the motor is currently located based on the d-axis current value, the q-axis current value, the d-axis voltage value, the q-axis voltage value, the maximum allowable bus voltage value, and the maximum current vector modulus value comprises: Acquire a voltage vector modulus value based on an absolute value of the d-axis voltage value and an absolute value of the q-axis voltage value, and acquire a current vector modulus value based on an absolute value of the d-axis current value and an absolute value of the q-axis current value; The control zone in which the motor is currently located is determined based on the voltage vector magnitude, the maximum allowable bus voltage value, the current vector magnitude, and the maximum current vector magnitude.

3. The motor weak magnetic field control method according to claim 2, characterized in that: Before the step of determining the control zone where the motor is currently located based on the voltage vector modulus, the maximum allowable bus voltage value, the current vector modulus and the maximum current vector modulus, the step further includes: Based on the real-time rotation speed and the execution torque, the currently corresponding maximum current vector modulus value is determined.

4. The motor weak magnetic field control method according to claim 1, characterized in that: When the control area is a deep magnetic weakening control area, the theoretical q-axis voltage value is set to zero, and based on the real-time motor flux, DC inductance value, AC inductance value, target speed and the execution torque of the motor, the step of obtaining the target dq-axis current combination boundary value includes: When the control area is the deep magnetic weakening control area, the theoretical q-axis voltage value is set to zero, and a theoretical d-axis current boundary value is determined based on the real-time motor flux, the DC inductance value and the target speed; Determining a theoretical q-axis current boundary value based on the theoretical d-axis current boundary value, the target speed, the execution torque, the real-time motor flux, the DC inductance value, and the AC inductance value; Based on the theoretical d-axis current boundary value and the theoretical q-axis current boundary value, the target dq-axis current combination boundary value is acquired.

5. The motor weak magnetic field control method according to claim 1, characterized in that: The step of outputting the target current and the target torque to the motor based on the target dq axis current combination boundary value, the d axis current value, the q axis current value and the preset parameter comparison table comprises: Determining an actual dq axis current combination boundary value based on the d axis current value and the q axis current value; When the actual dq axis current combination boundary value exceeds the target dq axis current combination boundary value, based on the target dq axis current combination boundary value and the preset parameter comparison table, output the corresponding target current and the target torque to the motor; Or, when the actual dq axis current combination boundary value does not exceed the target dq axis current combination boundary value, based on the actual dq axis current combination boundary value and the preset parameter comparison table, the corresponding target current and the target torque are output to the motor.

6. The motor weak magnetic field control method according to claim 5, characterized in that: After the step of determining the actual dq axis current combination boundary value based on the d axis current value and the q axis current value, the method further includes: When the actual dq-axis current combination boundary value is integrally saturated, acquiring the current corresponding real-time voltage vector modulus value based on the d-axis voltage value and the q-axis voltage value; The q-axis voltage value is switched to zero, and the d-axis current value is gradually increased and the absolute value of the d-axis current value is gradually decreased based on the preset step size until the real-time voltage vector modulus reaches the preset voltage value, so that the dq-axis current combination boundary value integral is desaturated.

7. The motor weak magnetic field control method according to claim 1, characterized in that: Before the step of setting the theoretical q-axis voltage value to zero and acquiring the target dq-axis current combination boundary value based on the real-time motor flux, DC inductance, AC inductance, target speed and execution torque of the motor when the control area is a deep magnetic weakening control area, the step further includes: Obtaining the working environment temperature of the motor, the number of motor poles, the preset mechanical speed in a no-load state, and the corresponding no-load back electromotive force; Obtaining a theoretical motor flux based on the preset mechanical speed, the no-load back electromotive force, and the number of motor pole pairs; Determining a flux compensation value based on the working environment temperature and a preset temperature compensation comparison table; The real-time motor flux is obtained based on the flux compensation value and the theoretical motor flux.

8. A motor weak magnetic field control device, characterized in that: The motor weak magnetic field control device comprises: the motor weak magnetic field control method comprises: An electrical parameter acquisition module, used to acquire the corresponding d-axis current value, q-axis current value, d-axis voltage value and q-axis voltage value in real time based on the current real-time speed and execution torque of the motor; a control zone determination module, configured to determine the control zone in which the motor is currently located based on the d-axis current value, the q-axis current value, the d-axis voltage value, the q-axis voltage value, the maximum allowable bus voltage value, and the maximum current vector modulus value; a target parameter acquisition module, for setting the theoretical q-axis voltage value to zero when the control area is a deep magnetic weakening control area, and acquiring a target dq-axis current combination boundary value based on the real-time motor flux, DC inductance value, AC inductance value, target speed and execution torque of the motor; A control parameter output module is used to output the target current and target torque to the motor based on the target dq axis current combination boundary value, the d axis current value, the q axis current value and a preset parameter comparison table, so that the motor performs deep magnetic weakening control.

9. A motor weak magnetic field control device, characterized in that: The motor weakening magnetic field control device comprises: a memory, a processor and a motor weakening magnetic field control program stored in the memory and executable on the processor, wherein the motor weakening magnetic field control program is configured to implement the steps of the motor weakening magnetic field control method as claimed in any one of claims 1 to 7.

10. A storage medium, characterized in that: The storage medium is a computer-readable storage medium, on which a motor flux-weakening control program is stored. When the motor flux-weakening control program is executed by a processor, the steps of the motor flux-weakening control method according to any one of claims 1 to 7 are implemented.

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