Motor magnetic weakening control method and device

Abstract

The present invention discloses a method and device for weakening magnetic field control of a motor. The method includes: obtaining the initial magnetic field vector and the reference magnetic field vector of the motor at the current moment; obtaining the reference magnetic field vector increment of the motor based on the initial magnetic field vector and the reference magnetic field vector; predicting the magnetic field vector increment of the motor at the next moment under each candidate switching state of the inverter; obtaining the weakening magnetic field compensation amount of the reference magnetic field vector based on the reference magnetic field vector increment and the magnetic field vector increment of the motor at the next moment under each candidate switching state; and performing weakening magnetic field control on the motor based on the weakening magnetic field compensation amount. Therefore, the method can perform weakening magnetic field control on the motor based on the weakening magnetic field compensation amount of the reference magnetic field vector of the motor, improve the response speed of the weakening magnetic field control of the motor, reduce the difficulty of the weakening magnetic field control of the motor, and is suitable for the weakening magnetic field control scenario of the motor without electrolytic capacitors.

Description

Technical Field

[0001] The present invention relates to the field of motor technology, and in particular to a motor magnetic weakening control method, device, motor, electronic equipment and computer-readable storage medium. Background Art

[0002] Currently, when the DC bus voltage is low, flux-weakening control is used to increase the motor's output capacity. However, conventional flux-weakening control methods suffer from slow response speeds, an inability to respond promptly to DC bus voltage fluctuations, and difficulty in controlling flux-weakening control. Summary of the Invention

[0003] The present invention aims to solve one of the technical problems in the above-mentioned technology at least to a certain extent.

[0004] To this end, one object of the present invention is to propose a method for weakening magnetic field control of a motor, which can perform weakening magnetic field control on the motor based on the weakening magnetic field compensation amount of the motor's reference flux vector, thereby improving the response speed of the motor's weakening magnetic field control and reducing the difficulty of the motor's weakening magnetic field control, and is suitable for motor weakening magnetic field control scenarios without electrolytic capacitors.

[0005] A second object of the present invention is to provide a magnetic field weakening control device for a motor.

[0006] The third object of the present invention is to provide a motor.

[0007] A fourth object of the present invention is to provide an electronic device.

[0008] A fifth object of the present invention is to provide a computer-readable storage medium.

[0009] To achieve the above-mentioned objectives, an embodiment of the first aspect of the present invention proposes a method for weakening magnetic field control of a motor, comprising: obtaining an initial magnetic field vector and a reference magnetic field vector of the motor at a current moment; obtaining a reference magnetic field vector increment of the motor based on the initial magnetic field vector and the reference magnetic field vector; predicting the magnetic field vector increment of the motor at the next moment under each candidate switching state of the inverter; obtaining a magnetic field weakening compensation amount of the reference magnetic field vector based on the reference magnetic field vector increment and the magnetic field vector increment of the motor at the next moment under each candidate switching state; and performing magnetic field weakening control on the motor based on the magnetic field weakening compensation amount.

[0010] According to the magnetic flux weakening control method of the motor according to the embodiment of the present invention, the reference magnetic flux vector increment of the motor can be obtained based on the initial magnetic flux vector and the reference magnetic flux vector of the motor at the current moment, and the magnetic flux vector increment of the motor at the next moment under each candidate switching state of the inverter can be predicted. Based on the reference magnetic flux vector increment and the magnetic flux vector increment of the motor at the next moment under each candidate switching state, the magnetic flux weakening compensation amount of the reference magnetic flux vector is obtained, and the motor is subjected to magnetic flux weakening control based on the magnetic flux weakening compensation amount. As a result, the motor can be subjected to magnetic flux weakening control based on the magnetic flux weakening compensation amount of the reference magnetic flux vector of the motor, which can improve the response speed of the motor magnetic flux weakening control and reduce the difficulty of the motor magnetic flux weakening control. The method is suitable for magnetic flux weakening control scenarios of motors without electrolytic capacitors.

[0011] In addition, the magnetic field weakening control method of the motor proposed in the above embodiment of the present invention may also have the following additional technical features:

[0012] In one embodiment of the present invention, obtaining the initial flux vector of the motor at a current moment includes: obtaining the three-phase stator current and the rotor position angle of the motor at a current moment; obtaining the direct-axis component and the quadrature-axis component of the stator current of the motor at a current moment based on the three-phase stator current; obtaining the rotor electrical angular velocity of the motor at a current moment based on the rotor position angle; obtaining the direct-axis component of the initial flux vector based on the direct-axis component of the stator current and the rotor electrical angular velocity; and obtaining the quadrature-axis component of the initial flux vector based on the quadrature-axis component of the stator current and the rotor electrical angular velocity.

[0013] In one embodiment of the present invention, obtaining the reference flux vector increment of the motor according to the initial flux vector and the reference flux vector includes: taking the difference between the reference flux vector and the initial flux vector as the reference flux vector increment.

[0014] In one embodiment of the present invention, the predicting of the flux vector increment of the motor at the next moment in each candidate switching state of the inverter includes: obtaining the DC bus voltage and rotor position angle of the motor at the current moment according to a sampling period; and predicting the flux vector increment of the motor at the next moment in any candidate switching state based on the DC bus voltage, the rotor position angle, the sampling period and any candidate switching state.

[0015] In one embodiment of the present invention, obtaining the weakening magnetic compensation amount of the reference flux vector according to the reference flux vector increment and the flux vector increment of the motor at the next moment in each candidate switching state includes: obtaining a target feedback amount of the regulator according to the reference flux vector increment and the flux vector increment of the motor at the next moment in each candidate switching state; and controlling the regulator to obtain the weakening magnetic compensation amount based on the target feedback amount.

[0016] In one embodiment of the present invention, obtaining the target feedback amount of the regulator based on the reference flux vector increment and the flux vector increment of the motor at the next moment in each candidate switching state includes: constructing a value function based on the reference flux vector increment and the flux vector increment at the next moment, wherein the value function is the absolute difference between the reference flux vector increment and the flux vector increment at the next moment; obtaining the optimal value of the value function based on the reference flux vector increment and the flux vector increment of the motor at the next moment in each candidate switching state, and using the optimal value as the target feedback amount.

[0017] In one embodiment of the present invention, the optimal value is the minimum value of the cost function.

[0018] In one embodiment of the present invention, it also includes: obtaining the DC bus voltage of the motor at the current moment according to the sampling period; obtaining a reference value of the value function according to the DC bus voltage and the sampling period, and using the reference value as the target reference quantity of the regulator; controlling the regulator to obtain the weakening magnetic compensation quantity based on the target feedback quantity, including: controlling the regulator to obtain the weakening magnetic compensation quantity based on the target feedback quantity and the target reference quantity.

[0019] In one embodiment of the present invention, the method further includes: using the candidate switching state corresponding to the optimal value as the target switching state of the inverter at the next moment; and controlling the switching state of the inverter according to the target switching state.

[0020] In one embodiment of the present invention, performing magnetic weakening control on the motor according to the magnetic weakening compensation amount includes: performing magnetic weakening compensation on the reference flux vector according to the magnetic weakening compensation amount to obtain a target reference flux vector; and performing magnetic weakening control on the motor according to the target reference flux vector.

[0021] In one embodiment of the present invention, performing magnetic weakening compensation on the reference magnetic flux vector according to the magnetic weakening compensation amount to obtain a target reference magnetic flux vector includes: obtaining the direct-axis component of the target reference magnetic flux vector according to the magnetic weakening compensation amount and the direct-axis component of the reference magnetic flux vector; obtaining the direct-axis inductance, quadrature-axis inductance, and stator current limit value of the motor; and obtaining the quadrature-axis component of the target reference magnetic flux vector according to the direct-axis inductance, the quadrature-axis inductance, the stator current limit value, and the magnetic weakening compensation amount.

[0022] To achieve the above-mentioned objectives, an embodiment of the second aspect of the present invention proposes a magnetic flux weakening control device for a motor, comprising: a first acquisition module, used to obtain the initial magnetic flux vector and the reference magnetic flux vector of the motor at the current moment; a second acquisition module, used to obtain the reference magnetic flux vector increment of the motor based on the initial magnetic flux vector and the reference magnetic flux vector; a prediction module, used to predict the magnetic flux vector increment of the motor at the next moment under each candidate switching state of the inverter; a third acquisition module, used to obtain the magnetic flux weakening compensation amount of the reference magnetic flux vector based on the reference magnetic flux vector increment and the magnetic flux vector increment of the motor at the next moment under each candidate switching state; and a control module, used to perform magnetic flux weakening control on the motor based on the magnetic flux weakening compensation amount.

[0023] The magnetic flux weakening control device of the motor of the embodiment of the present invention can obtain the reference magnetic flux vector increment of the motor based on the initial magnetic flux vector and the reference magnetic flux vector at the current moment of the motor, and predict the magnetic flux vector increment of the motor at the next moment under each candidate switching state of the inverter. According to the reference magnetic flux vector increment and the magnetic flux vector increment of the motor at the next moment under each candidate switching state, the magnetic flux weakening compensation amount of the reference magnetic flux vector is obtained, and the motor is subjected to magnetic flux weakening control based on the magnetic flux weakening compensation amount. As a result, the motor can be subjected to magnetic flux weakening control based on the magnetic flux weakening compensation amount of the reference magnetic flux vector of the motor, which can improve the response speed of the magnetic flux weakening control of the motor, reduce the difficulty of the magnetic flux weakening control of the motor, and is suitable for the magnetic flux weakening control scenario of the motor without electrolytic capacitors.

[0024] In addition, the magnetic field weakening control device of the motor proposed in the above embodiment of the present invention may also have the following additional technical features:

[0025] In one embodiment of the present invention, the first acquisition module is further used to: obtain the three-phase stator current and rotor position angle of the motor at the current moment; obtain the direct-axis component and quadrature-axis component of the stator current of the motor at the current moment based on the three-phase stator current; obtain the rotor electrical angular velocity of the motor at the current moment based on the rotor position angle; obtain the direct-axis component of the initial magnetic flux vector based on the direct-axis component of the stator current and the rotor electrical angular velocity; obtain the quadrature-axis component of the initial magnetic flux vector based on the quadrature-axis component of the stator current and the rotor electrical angular velocity.

[0026] In one embodiment of the present invention, the second acquisition module is further configured to: use the difference between the reference flux linkage vector and the initial flux linkage vector as the reference flux linkage vector increment.

[0027] In one embodiment of the present invention, the prediction module is further used to: obtain the DC bus voltage and rotor position angle of the motor at the current moment according to the sampling period; and predict the flux vector increment of the motor at the next moment under any candidate switching state based on the DC bus voltage, the rotor position angle, the sampling period and any candidate switching state.

[0028] In one embodiment of the present invention, the third acquisition module is further used to: obtain the target feedback amount of the regulator based on the reference flux vector increment and the flux vector increment of the motor at the next moment in each candidate switching state; and control the regulator to obtain the weakening magnetic compensation amount based on the target feedback amount.

[0029] In one embodiment of the present invention, the third acquisition module is further used to: construct a value function based on the reference flux vector increment and the flux vector increment at the next moment, wherein the value function is the absolute difference between the reference flux vector increment and the flux vector increment at the next moment; obtain the optimal value of the value function based on the reference flux vector increment and the flux vector increment of the motor at the next moment in each candidate switching state, and use the optimal value as the target feedback amount.

[0030] In one embodiment of the present invention, the optimal value is the minimum value of the cost function.

[0031] In one embodiment of the present invention, the third acquisition module is further used to: obtain the DC bus voltage of the motor at the current moment according to the sampling period; obtain a reference value of the value function based on the DC bus voltage and the sampling period, and use the reference value as the target reference quantity of the regulator; the third acquisition module is further used to: control the regulator to obtain the weak magnetic compensation quantity based on the target feedback quantity and the target reference quantity.

[0032] In one embodiment of the present invention, the control module is further configured to: use the candidate switching state corresponding to the optimal value as the target switching state of the inverter at the next moment; and control the switching state of the inverter according to the target switching state.

[0033] In one embodiment of the present invention, the control module is further configured to: perform magnetic weakening compensation on the reference flux vector according to the magnetic weakening compensation amount to obtain a target reference flux vector; and perform magnetic weakening control on the motor according to the target reference flux vector.

[0034] In one embodiment of the present invention, the control module is further used to: obtain the direct-axis component of the target reference flux vector based on the weakening flux compensation amount and the direct-axis component of the reference flux vector; obtain the direct-axis inductance, quadrature-axis inductance and stator current limit value of the motor; and obtain the quadrature-axis component of the target reference flux vector based on the direct-axis inductance, the quadrature-axis inductance, the stator current limit value and the weakening flux compensation amount.

[0035] To achieve the above-mentioned object, a third embodiment of the present invention provides a motor, comprising the magnetic field weakening control device of the motor described in the second embodiment of the present invention.

[0036] The motor of the embodiment of the present invention can obtain the reference flux vector increment of the motor based on the initial flux vector and the reference flux vector at the current moment of the motor, and predict the flux vector increment of the motor at the next moment under each candidate switching state of the inverter. Based on the reference flux vector increment and the flux vector increment of the motor at the next moment under each candidate switching state, the weakening magnetic field compensation amount of the reference flux vector is obtained, and the motor is subjected to weakening magnetic field control based on the weakening magnetic field compensation amount. As a result, the motor can be subjected to weakening magnetic field control based on the weakening magnetic field compensation amount of the reference flux vector of the motor, which can improve the response speed of the motor's weakening magnetic field control and reduce the difficulty of the motor's weakening magnetic field control. The motor is suitable for weakening magnetic field control scenarios of motors without electrolytic capacitors.

[0037] To achieve the above-mentioned purpose, the fourth embodiment of the present invention proposes an electronic device, including a memory and a processor; wherein the processor runs a program corresponding to the executable program code by reading the executable program code stored in the memory, so as to implement the weak magnetic field control method of the motor described in the first embodiment of the present invention.

[0038] The electronic device of the embodiment of the present invention can obtain the reference flux vector increment of the motor based on the initial flux vector and the reference flux vector of the motor at the current moment, and predict the flux vector increment of the motor at the next moment under each candidate switching state of the inverter. According to the reference flux vector increment and the flux vector increment of the motor at the next moment under each candidate switching state, the weakening magnetic compensation amount of the reference flux vector is obtained, and the motor is subjected to weakening magnetic control based on the weakening magnetic compensation amount. As a result, the motor can be subjected to weakening magnetic control based on the weakening magnetic compensation amount of the reference flux vector of the motor, which can improve the response speed of the motor's weakening magnetic control and reduce the difficulty of the motor's weakening magnetic control. The device is suitable for the weakening magnetic control scenario of the motor without electrolytic capacitors.

[0039] To achieve the above-mentioned purpose, the fifth embodiment of the present invention proposes a computer-readable storage medium, which stores a computer program. When the program is executed by a processor, it implements the weak magnetic control method of the motor described in the first embodiment of the present invention.

[0040] The computer-readable storage medium of an embodiment of the present invention, by storing a computer program and being executed by a processor, can obtain the reference flux vector increment of the motor based on the initial flux vector and the reference flux vector of the motor at the current moment, and predict the flux vector increment of the motor at the next moment under each candidate switching state of the inverter. Based on the reference flux vector increment and the flux vector increment of the motor at the next moment under each candidate switching state, the weakening magnetic field compensation amount of the reference flux vector is obtained, and the motor is subjected to weakening magnetic field control based on the weakening magnetic field compensation amount. As a result, the motor can be subjected to weakening magnetic field control based on the weakening magnetic field compensation amount of the reference flux vector of the motor, which can improve the response speed of the motor's weakening magnetic field control and reduce the difficulty of the motor's weakening magnetic field control. The motor is suitable for weakening magnetic field control scenarios of motors without electrolytic capacitors.

[0041] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0043] Figure 1 is a flow chart of a magnetic field weakening control method for a motor according to one embodiment of the present invention;

[0044] Figure 2 A flowchart of obtaining an initial flux vector in a magnetic field weakening control method for a motor according to an embodiment of the present invention;

[0045] Figure 3 A flowchart of obtaining a magnetic field weakening compensation amount in a magnetic field weakening control method of a motor according to an embodiment of the present invention;

[0046] Figure 4 is a block diagram of a magnetic field weakening control device for a motor according to an embodiment of the present invention;

[0047] Figure 5 is a block diagram of a motor according to one embodiment of the present invention; and

[0048] Figure 6 FIG. 1 is a block diagram of an electronic device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0049] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0050] The following describes a magnetic field weakening control method, device, motor, electronic device, and computer-readable storage medium for a motor according to embodiments of the present invention with reference to the accompanying drawings.

[0051] Figure 1 4 is a flow chart of a magnetic field weakening control method for a motor according to an embodiment of the present invention.

[0052] S101, obtaining the initial flux vector and reference flux vector of the motor at the current moment.

[0053] In embodiments of the present invention, the current initial flux vector and reference flux vector of the motor can be obtained. It is understood that the flux vector includes a direct-axis component and a quadrature-axis component. For example, the initial flux vector includes a direct-axis component of the initial flux vector and a quadrature-axis component of the initial flux vector, and the reference flux vector includes a direct-axis component of the reference flux vector and a quadrature-axis component of the reference flux vector.

[0054] In one embodiment, obtaining the initial flux vector of the motor at the current moment may include obtaining the direct-axis component and the quadrature-axis component of the stator current of the motor at the current moment, obtaining the direct-axis component of the initial flux vector of the motor at the current moment based on the direct-axis component of the stator current of the motor at the current moment, and obtaining the quadrature-axis component of the initial flux vector of the motor at the current moment based on the quadrature-axis component of the stator current of the motor at the current moment.

[0055] In one embodiment, obtaining the reference flux vector of the motor may include obtaining the rotor permanent magnet flux of the motor, using the rotor permanent magnet flux as the direct-axis component of the reference flux vector, obtaining the quadrature-axis inductance, reference motor torque, pole pair number, and rotor permanent magnet flux of the motor, and obtaining the quadrature-axis component of the reference flux vector based on the quadrature-axis inductance, reference motor torque, pole pair number, and rotor permanent magnet flux.

[0056] For example, obtaining the reference flux vector of the motor can be achieved through the following formula:

[0057]

[0058]

[0059] Among them, ψ d ref is the direct axis component of the reference flux vector, ψ q ref is the quadrature axis component of the reference flux vector, ψ f is the magnetic flux of the rotor permanent magnet, n p is the pole pair number, L q is the quadrature-axis inductance, T e ref is the reference motor torque.

[0060] S102 : Obtain a reference flux vector increment of the motor according to the initial flux vector and the reference flux vector.

[0061] In one embodiment, obtaining a reference flux vector increment of the motor based on the initial flux vector and the reference flux vector may include using the difference between the reference flux vector and the initial flux vector as the reference flux vector increment. It is understood that if the difference is large, the reference flux vector increment is also large, indicating a large deviation between the initial flux vector and the reference flux vector. Conversely, if the difference is small, the reference flux vector increment is also small, indicating a small deviation between the initial flux vector and the reference flux vector.

[0062] In one embodiment, obtaining a reference flux vector increment of the motor based on the initial flux vector and the reference flux vector may include using the ratio between the reference flux vector and the initial flux vector as the reference flux vector increment. It is understood that if the ratio is closer to 1, the reference flux vector increment is also closer to 1, indicating that the deviation between the initial flux vector and the reference flux vector is smaller. Conversely, if the ratio is closer to 0, the reference flux vector increment is also closer to 0, indicating that the deviation between the initial flux vector and the reference flux vector is larger.

[0063] S103 , predicting the flux vector increment of the motor at the next moment in each candidate switching state of the inverter.

[0064] In the embodiments of the present invention, the inverter includes switching devices, and there are no particular limitations on the type and topology of the switching devices. For example, the switching devices include, but are not limited to, diodes, IGBTs (Insulated Gate Bipolar Transistors), and MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors). For example, the inverter may have a three-phase bridge structure.

[0065] In an embodiment of the present invention, the inverter may have at least one candidate switching state. It should be noted that the candidate switching state refers to the candidate switching state of the switching device in the inverter, and the representation method of the switching state is not limited in many ways.

[0066] For example, when the inverter is a three-phase bridge structure, each bridge arm may have two candidate switch states. The first candidate switch state is that the upper bridge arm is on and the lower bridge arm is off, which can be represented by the value 1. The second candidate switch state is that the upper bridge arm is off and the lower bridge arm is on, which can be represented by the value 0. At this time, the inverter may have 8 candidate switch states, namely S1 (100), S2 (110), S3 (010), S4 (011), S5 (001), S6 (101), S7 (000) and S8 (111). Each candidate switch state of the inverter may include three values, which represent the candidate switch states of the first bridge arm, the second bridge arm, and the third bridge arm of the inverter from left to right. For example, S1 (100) indicates that the upper bridge arm of the first bridge arm of the inverter is on and the lower bridge arm is off, the upper bridge arm of the second bridge arm is off and the lower bridge arm is on, and the upper bridge arm of the third bridge arm is off and the lower arm is on.

[0067] In the embodiment of the present invention, the flux vector increment of the motor at the next moment in each candidate switching state of the inverter can be predicted. It is understandable that the flux vector increment of the motor at the next moment in different candidate switching states may be different.

[0068] In one embodiment, predicting the motor's flux vector increment at the next moment in each candidate switching state of the inverter may include obtaining the motor's current DC bus voltage and rotor position angle according to a sampling period, and predicting the motor's flux vector increment at the next moment in each candidate switching state based on the DC bus voltage, rotor position angle, sampling period, and each candidate switching state. It should be noted that the sampling period is not excessively limited; for example, the sampling period can be 2 seconds. Thus, this method comprehensively considers the impact of the DC bus voltage, rotor position angle, sampling period, and each candidate switching state on the flux vector increment at the next moment, resulting in a more accurate flux vector increment.

[0069] In one embodiment, the DC bus voltage may be obtained by a voltage detection device, which may include a voltage sensor.

[0070] In one embodiment, the rotor position angle may be acquired by an angle detection device, which may include an angle sensor, a camera, and the like.

[0071] For example, the prediction of the next moment's flux vector increment of the motor under each candidate switching state of the inverter can be achieved by the following formula:

[0072]

[0073] Where Δψ d (k+1) is the direct axis component of the flux vector increment at the next moment, Δψ q(k+1) is the quadrature axis component of the flux vector increment at the next moment, V dc is the DC bus voltage, T s is the sampling period, θ r is the rotor position angle, S a 、S b and S c They are the candidate switching states of the first bridge arm, the second bridge arm, and the third bridge arm of the inverter respectively.

[0074] S104 , obtaining a flux weakening compensation amount of the reference flux vector according to the reference flux vector increment and the flux vector increment of the motor at the next moment in each candidate switching state.

[0075] In one embodiment, obtaining a field weakening compensation amount for the reference flux vector based on a reference flux vector increment and a flux vector increment at a subsequent moment of the motor in each candidate switching state may include inputting the reference flux vector increment and the flux vector increment at a subsequent moment of the motor in each candidate switching state into a setting algorithm and / or a setting model to obtain the field weakening compensation amount for the reference flux vector. It should be noted that the setting algorithm and / or setting model are not particularly limited.

[0076] In one embodiment, obtaining a field-weakening compensation amount for a reference flux vector based on a reference flux vector increment and a flux vector increment at a next moment of the motor in each candidate switching state may include pre-establishing a mapping relationship or mapping table between the reference flux vector increment, the flux vector increment at the next moment, and the field-weakening compensation amount. After obtaining the reference flux vector increment and the flux vector increment at the next moment of the motor in each candidate switching state, the field-weakening compensation amount may be obtained by querying the mapping relationship or mapping table. It should be noted that the mapping relationship or mapping table is not particularly limited.

[0077] S105: Perform magnetic weakening control on the motor according to the magnetic weakening compensation amount.

[0078] In one embodiment, performing magnetic weakening control on the motor according to the magnetic weakening compensation amount may include determining the magnetic weakening current and / or magnetic weakening voltage of the motor according to the magnetic weakening compensation amount, and performing magnetic weakening control on the motor according to the magnetic weakening current and / or magnetic weakening voltage.

[0079] In one embodiment, performing field weakening control on the motor according to the field weakening compensation amount may include performing field weakening compensation on a reference flux vector according to the field weakening compensation amount to obtain a target reference flux vector, and performing field weakening control on the motor according to the target reference flux vector.

[0080] In one embodiment, the motor includes a regulator for performing field-weakening compensation on a reference flux vector. Performing field-weakening compensation on the reference flux vector based on a field-weakening compensation amount to obtain a target reference flux vector may include controlling the regulator to perform field-weakening compensation on the reference flux vector based on the field-weakening compensation amount to obtain the target reference flux vector. It should be noted that the structure of the regulator is not particularly limited; for example, the regulator includes, but is not limited to, a proportional regulator, a proportional-integral regulator, a proportional-derivative regulator, and the like.

[0081] In one embodiment, performing magnetic weakening compensation on a reference flux vector according to a magnetic weakening compensation amount to obtain a target reference flux vector may include obtaining the direct-axis component of the target reference flux vector according to the magnetic weakening compensation amount and the direct-axis component of the reference flux vector, obtaining the direct-axis inductance, quadrature-axis inductance, and stator current limit value of the motor, and obtaining the quadrature-axis component of the target reference flux vector according to the direct-axis inductance, quadrature-axis inductance, stator current limit value, and magnetic weakening compensation amount.

[0082] For example, according to the weakening magnetic compensation amount, the reference magnetic flux vector is weakened to obtain the target reference magnetic flux vector, which can be achieved by the following formula:

[0083]

[0084]

[0085] Among them, ψ' d ref is the direct axis component of the target reference flux vector, ψ' q ref is the quadrature axis component of the target reference flux vector, ψ d ref is the direct axis component of the reference flux vector, Δψ FW is the weak magnetic compensation, L d is the direct-axis inductance, L q is the quadrature-axis inductance, I max is the stator current limit value.

[0086] In one embodiment, performing flux weakening control on the motor according to the target reference flux vector may include determining the flux weakening current and / or flux weakening voltage of the motor according to the target reference flux vector, and performing flux weakening control on the motor according to the flux weakening current and / or flux weakening voltage.

[0087] In summary, according to the magnetic flux weakening control method of the motor of the embodiment of the present invention, the reference magnetic flux vector increment of the motor can be obtained based on the initial magnetic flux vector and the reference magnetic flux vector of the motor at the current moment, and the magnetic flux vector increment of the motor at the next moment in each candidate switching state of the inverter can be predicted. According to the reference magnetic flux vector increment and the magnetic flux vector increment of the motor at the next moment in each candidate switching state, the magnetic flux weakening compensation amount of the reference magnetic flux vector is obtained, and the motor is subjected to magnetic flux weakening control based on the magnetic flux weakening compensation amount. Therefore, the motor can be subjected to magnetic flux weakening control based on the magnetic flux weakening compensation amount of the reference magnetic flux vector of the motor, which can improve the response speed of the magnetic flux weakening control of the motor, reduce the difficulty of the magnetic flux weakening control of the motor, and is suitable for the magnetic flux weakening control scenario of the motor without electrolytic capacitors.

[0088] Based on any of the above embodiments, Figure 2 As shown, obtaining the initial flux vector of the motor at the current moment in step S101 may include:

[0089] S201, obtaining the three-phase stator current and rotor position angle of the motor at the current moment.

[0090] In one embodiment, the three-phase stator current and rotor position angle of the motor at the current moment can be obtained according to the sampling period. It should be noted that the relevant contents of the sampling period and the rotor position angle can be referred to the above embodiment and will not be repeated here.

[0091] In one embodiment, the three-phase stator current can be obtained by a current detection device. For example, the current detection device can include a current sensor.

[0092] S202 , obtaining the direct-axis component and the quadrature-axis component of the stator current of the motor at the current moment according to the three-phase stator current.

[0093] It is understandable that the direct-axis component and the quadrature-axis component of the stator current can be obtained based on the three-phase stator current. The specific method of obtaining the direct-axis component and the quadrature-axis component of the stator current of the motor at the current moment based on the three-phase stator current is not limited in detail.

[0094] S203: Obtain the rotor electrical angular velocity of the motor at the current moment according to the rotor position angle.

[0095] It is understood that the rotor electrical angular velocity can be obtained based on the rotor position angle. The specific method for obtaining the current rotor electrical angular velocity of the motor based on the rotor position angle is not particularly limited. For example, the rotor electrical angular velocity can be obtained by differentiating the rotor position angle.

[0096] S204 , obtaining the direct-axis component of the initial magnetic flux vector according to the direct-axis component of the stator current and the rotor electrical angular velocity.

[0097] In one embodiment, obtaining the direct-axis component of the initial flux vector based on the direct-axis component of the stator current and the rotor electrical angular velocity may include inputting the direct-axis component of the stator current and the rotor electrical angular velocity into a setting algorithm and / or a setting model to obtain the direct-axis component of the initial flux vector. It should be noted that the setting algorithm and / or setting model are not particularly limited.

[0098] In one embodiment, obtaining the direct-axis component of the initial flux vector based on the direct-axis component of the stator current and the rotor electrical angular velocity may include pre-establishing a mapping relationship or mapping table between the direct-axis component of the stator current, the rotor electrical angular velocity, and the direct-axis component of the initial flux vector. After obtaining the direct-axis component of the stator current and the rotor electrical angular velocity, the direct-axis component of the initial flux vector may be obtained by querying the mapping relationship or mapping table. It should be noted that the mapping relationship or mapping table is not particularly limited.

[0099] In one embodiment, obtaining the direct-axis component of the initial flux vector based on the direct-axis component of the stator current and the rotor electrical angular velocity may include obtaining the direct-axis component and the quadrature-axis component of the stator flux vector of the motor at the current moment, the stator winding resistance, and the sampling period. Obtaining the direct-axis component of the initial flux vector based on the direct-axis component and the quadrature-axis component of the stator flux vector of the motor at the current moment, the stator winding resistance, the sampling period, the direct-axis component of the stator current, and the rotor electrical angular velocity.

[0100] For example, the direct-axis component of the initial flux vector can be obtained based on the direct-axis component of the stator current and the rotor electrical angular velocity, which can be achieved by the following formula:

[0101] ψ 0d (k)=ψ d (k)-[R s i d (k)-ω e ψ q (k)]·T s

[0102] Among them, ψ 0d (k) is the direct axis component of the initial magnetic flux vector at the current moment, ψ d (k) is the direct axis component of the stator flux vector at the current moment, ψ q (k) is the quadrature axis component of the stator flux vector at the current moment, R s is the stator winding resistance, i d (k) is the direct axis component of the stator current at the current moment, ω e is the rotor electrical angular velocity, T s is the sampling period.

[0103] S205 , obtaining the quadrature-axis component of the initial magnetic flux vector according to the quadrature-axis component of the stator current and the rotor electrical angular velocity.

[0104] In one embodiment, obtaining the quadrature-axis component of the initial flux vector based on the quadrature-axis component of the stator current and the rotor electrical angular velocity may include obtaining the direct-axis component and the quadrature-axis component of the stator flux vector of the motor at the current moment, the stator winding resistance, and the sampling period, and obtaining the quadrature-axis component of the initial flux vector based on the direct-axis component and the quadrature-axis component of the stator flux vector of the motor at the current moment, the stator winding resistance, the sampling period, the quadrature-axis component of the stator current, and the rotor electrical angular velocity.

[0105] For example, the quadrature-axis component of the initial flux vector can be obtained based on the quadrature-axis component of the stator current and the rotor electrical angular velocity, which can be achieved by the following formula:

[0106] ψ 0q (k)=ψ q (k)-[R s i q (k)+ω e ψ d (k)]·T s

[0107] Among them, ψ 0q (k) is the quadrature component of the initial magnetic flux vector at the current moment, ψ d (k) is the direct axis component of the stator flux vector at the current moment, ψ q (k) is the quadrature axis component of the stator flux vector at the current moment, R s is the stator winding resistance, i q (k) is the quadrature axis component of the stator current at the current moment, ω e is the rotor electrical angular velocity, T s is the sampling period.

[0108] It should be noted that the relevant content of step S205 can be found in step S204 and will not be repeated here.

[0109] Therefore, this method can obtain the direct-axis component and the quadrature-axis component of the stator current of the motor at the current moment according to the three-phase stator current of the motor at the current moment, obtain the rotor electrical angular velocity of the motor at the current moment according to the rotor position angle of the motor at the current moment, obtain the direct-axis component of the initial magnetic flux vector according to the direct-axis component of the stator current and the rotor electrical angular velocity, and obtain the quadrature-axis component of the initial magnetic flux vector according to the quadrature-axis component of the stator current and the rotor electrical angular velocity, so as to achieve the acquisition of the initial magnetic flux vector.

[0110] Based on any of the above embodiments, Figure 3 As shown, in step S104, obtaining the flux weakening compensation amount of the reference flux vector according to the reference flux vector increment and the flux vector increment of the motor at the next moment in each candidate switching state may include:

[0111] S301 , obtaining a target feedback amount of a regulator according to a reference flux vector increment and a flux vector increment of the motor at the next moment in each candidate switching state.

[0112] In the embodiment of the present invention, the motor has a regulator. It should be noted that the relevant contents of the regulator can be found in the above embodiment and will not be repeated here.

[0113] In one embodiment, obtaining a target feedback amount for the regulator based on a reference flux vector increment and the flux vector increment at the next moment of the motor in each candidate switching state may include constructing a value function based on the reference flux vector increment and the flux vector increment at the next moment, wherein the value function is the absolute difference between the reference flux vector increment and the flux vector increment at the next moment. Based on the reference flux vector increment and the flux vector increment at the next moment of the motor in each candidate switching state, an optimal value of the value function is obtained, and the optimal value is used as the target feedback amount. It should be noted that there are no restrictions on the optimal value of the value function; for example, the optimal value is the minimum value of the value function.

[0114] For example, the value function C is as follows:

[0115] C=|Δψ dq ref -Δψ dq (k+1)|

[0116] Where Δψ dq ref is the reference flux vector increment, Δψ dq (k+1) is the flux vector increment at the next moment.

[0117] For example, when the optimal value is the minimum value of the value function, the reference flux vector increment and the flux vector increment of the motor at the next moment in any candidate switching state can be substituted into the value function to obtain a value of the value function. The minimum value of all values of the value function can be taken as the optimal value, and the optimal value can be used as the target feedback amount.

[0118] S302, controlling the regulator to obtain a magnetic weakening compensation amount based on a target feedback amount.

[0119] In one embodiment, controlling the regulator to obtain the field-weakening compensation amount based on the target feedback amount may include controlling the regulator to obtain the field-weakening compensation amount based on the target feedback amount and an adjustment parameter. It should be noted that there are no excessive restrictions on the type of adjustment parameter. For example, when the regulator is a proportional regulator, the adjustment parameter may include a proportional coefficient; when the regulator is a proportional-integral regulator, the adjustment parameter may include a proportional coefficient and an integral time constant; and when the regulator is a proportional-differential regulator, the adjustment parameter may include a proportional coefficient and a differential time constant.

[0120] In one embodiment, controlling the regulator to obtain the field weakening compensation amount based on the target feedback amount may include controlling the regulator to obtain the field weakening compensation amount based on the target feedback amount and a target reference amount, wherein the target reference amount is a reference value of the cost function.

[0121] For example, when the regulator is a proportional-integral regulator, the control regulator obtains the weak magnetic compensation amount based on the target feedback amount and the target reference amount, which can be achieved by the following formula:

[0122]

[0123] Where Δψ FW is the weak magnetic compensation, C ref is the target reference quantity, C opt is the target feedback amount, K p is the proportional coefficient of the regulator, K i is the integral time constant of the regulator, and 1 / s is the integral symbol.

[0124] In one embodiment, obtaining the reference value of the cost function may include obtaining the DC bus voltage of the motor at the current moment according to a sampling period, and obtaining the reference value of the cost function based on the DC bus voltage and the sampling period.

[0125] For example, according to the DC bus voltage and the sampling period, the reference value of the value function can be obtained by the following formula:

[0126]

[0127] Among them, C ref is the reference value of the value function, Δψ dq Flux vector increment, V dc is the DC bus voltage, T s is the sampling period.

[0128] Therefore, in this method, the target feedback amount of the regulator can be obtained according to the reference flux vector increment and the flux vector increment of the motor at the next moment in each candidate switching state, and the regulator can be controlled to obtain the weakening magnetic compensation amount based on the target feedback amount, so that the weakening magnetic compensation amount can be obtained through the regulator.

[0129] Based on any of the above embodiments, the candidate switching state corresponding to the optimal value may be used as the target switching state of the inverter at the next moment, and the switching state of the inverter may be controlled according to the target switching state.

[0130] For example, when the optimal value is the minimum value of the cost function, the candidate switching state corresponding to the minimum value of the cost function can be obtained as the target switching state of the inverter at the next moment. For example, if the candidate switching state corresponding to the minimum value of the cost function is S1(100), S1(100) can be used as the target switching state of the inverter at the next moment.

[0131] In one embodiment, controlling the switching state of the inverter according to the target switching state may include controlling the switching state of the inverter to be adjusted to the target switching state.

[0132] Therefore, in this method, the candidate switching state corresponding to the optimal value can be used as the target switching state of the inverter at the next moment, and the switching state of the inverter is controlled according to the target switching state, thereby improving the flexibility of the switching state of the inverter.

[0133] Figure 4 FIG. 4 is a block diagram of a magnetic field weakening control device for a motor according to an embodiment of the present invention.

[0134] like Figure 4 As shown, the magnetic field weakening control device 100 of the motor according to the embodiment of the present invention includes: a first acquisition module 11 , a second acquisition module 12 , a prediction module 13 , a third acquisition module 14 and a control module 15 .

[0135] The first acquisition module 11 is used to obtain the initial flux vector and the reference flux vector of the motor at the current moment;

[0136] The second acquisition module 12 is used to obtain a reference flux vector increment of the motor according to the initial flux vector and the reference flux vector;

[0137] The prediction module 13 is used to predict the flux vector increment of the motor at the next moment under each candidate switching state of the inverter;

[0138] The third acquisition module 14 is configured to acquire a flux weakening compensation amount of the reference flux vector according to the reference flux vector increment and the flux vector increment of the motor at the next moment in each candidate switching state;

[0139] The control module 15 is configured to perform magnetic field weakening control on the motor according to the magnetic field weakening compensation amount.

[0140] In one embodiment of the present invention, the first acquisition module 11 is further used to: obtain the three-phase stator current and rotor position angle of the motor at the current moment; obtain the direct-axis component and quadrature-axis component of the stator current of the motor at the current moment based on the three-phase stator current; obtain the rotor electrical angular velocity of the motor at the current moment based on the rotor position angle; obtain the direct-axis component of the initial magnetic flux vector based on the direct-axis component of the stator current and the rotor electrical angular velocity; obtain the quadrature-axis component of the initial magnetic flux vector based on the quadrature-axis component of the stator current and the rotor electrical angular velocity.

[0141] In one embodiment of the present invention, the second acquisition module 12 is further configured to use the difference between the reference flux linkage vector and the initial flux linkage vector as the reference flux linkage vector increment.

[0142] In one embodiment of the present invention, the prediction module 13 is further used to: obtain the DC bus voltage and rotor position angle of the motor at the current moment according to the sampling period; and predict the flux vector increment of the motor at the next moment under any candidate switching state based on the DC bus voltage, the rotor position angle, the sampling period and any candidate switching state.

[0143] In one embodiment of the present invention, the third acquisition module 14 is further used to: obtain a target feedback amount of the regulator based on the reference flux vector increment and the flux vector increment of the motor at the next moment in each candidate switching state; and control the regulator to obtain the weakening magnetic compensation amount based on the target feedback amount.

[0144] In one embodiment of the present invention, the third acquisition module 14 is further used to: construct a value function based on the reference flux vector increment and the flux vector increment at the next moment, wherein the value function is the absolute difference between the reference flux vector increment and the flux vector increment at the next moment; obtain the optimal value of the value function based on the reference flux vector increment and the flux vector increment of the motor at the next moment in each candidate switching state, and use the optimal value as the target feedback amount.

[0145] In one embodiment of the present invention, the optimal value is the minimum value of the cost function.

[0146] In one embodiment of the present invention, the third acquisition module 14 is further used to: obtain the DC bus voltage of the motor at the current moment according to the sampling period; obtain a reference value of the value function based on the DC bus voltage and the sampling period, and use the reference value as the target reference quantity of the regulator; the third acquisition module is further used to: control the regulator to obtain the weak magnetic compensation quantity based on the target feedback quantity and the target reference quantity.

[0147] In one embodiment of the present invention, the control module 15 is further configured to: use the candidate switching state corresponding to the optimal value as the target switching state of the inverter at the next moment; and control the switching state of the inverter according to the target switching state.

[0148] In one embodiment of the present invention, the control module 15 is further configured to: perform magnetic weakening compensation on the reference flux vector according to the magnetic weakening compensation amount to obtain a target reference flux vector; and perform magnetic weakening control on the motor according to the target reference flux vector.

[0149] In one embodiment of the present invention, the control module 15 is further used to: obtain the direct-axis component of the target reference flux vector based on the weakening flux compensation amount and the direct-axis component of the reference flux vector; obtain the direct-axis inductance, quadrature-axis inductance and stator current limit value of the motor; and obtain the quadrature-axis component of the target reference flux vector based on the direct-axis inductance, the quadrature-axis inductance, the stator current limit value and the weakening flux compensation amount.

[0150] It should be noted that for details not disclosed in the magnetic field weakening control device of the motor in the embodiment of the present invention, please refer to the details disclosed in the magnetic field weakening control method of the motor in the above embodiment of the present invention, which will not be repeated here.

[0151] In summary, the magnetic flux weakening control device of the motor in the embodiment of the present invention can obtain the reference magnetic flux vector increment of the motor based on the initial magnetic flux vector and the reference magnetic flux vector at the current moment of the motor, and predict the magnetic flux vector increment of the motor at the next moment under each candidate switching state of the inverter. According to the reference magnetic flux vector increment and the magnetic flux vector increment of the motor at the next moment under each candidate switching state, the magnetic flux weakening compensation amount of the reference magnetic flux vector is obtained, and the motor is subjected to magnetic flux weakening control based on the magnetic flux weakening compensation amount. Therefore, the motor can be subjected to magnetic flux weakening control based on the magnetic flux weakening compensation amount of the reference magnetic flux vector of the motor, which can improve the response speed of the magnetic flux weakening control of the motor, reduce the difficulty of the magnetic flux weakening control of the motor, and is suitable for the magnetic flux weakening control scenario of the motor without electrolytic capacitors.

[0152] In order to implement the above embodiment, the present invention further proposes a motor 200, such as Figure 5 As shown, the motor 200 according to the embodiment of the present invention includes the above-mentioned magnetic field weakening control device 100 of the motor.

[0153] The motor of the embodiment of the present invention can obtain the reference flux vector increment of the motor based on the initial flux vector and the reference flux vector at the current moment of the motor, and predict the flux vector increment of the motor at the next moment under each candidate switching state of the inverter. Based on the reference flux vector increment and the flux vector increment of the motor at the next moment under each candidate switching state, the weakening magnetic field compensation amount of the reference flux vector is obtained, and the motor is subjected to weakening magnetic field control based on the weakening magnetic field compensation amount. As a result, the motor can be subjected to weakening magnetic field control based on the weakening magnetic field compensation amount of the reference flux vector of the motor, which can improve the response speed of the motor's weakening magnetic field control and reduce the difficulty of the motor's weakening magnetic field control. The motor is suitable for weakening magnetic field control scenarios of motors without electrolytic capacitors.

[0154] In order to implement the above embodiment, the present invention further proposes an electronic device 300, such as Figure 6 As shown, the electronic device 300 includes a memory 31 and a processor 32. The processor 32 reads the executable program code stored in the memory 31 to run a program corresponding to the executable program code, so as to implement the above-mentioned motor flux weakening control method.

[0155] The electronic device of the embodiment of the present invention can obtain the reference flux vector increment of the motor based on the initial flux vector and the reference flux vector of the motor at the current moment, and predict the flux vector increment of the motor at the next moment under each candidate switching state of the inverter. According to the reference flux vector increment and the flux vector increment of the motor at the next moment under each candidate switching state, the weakening magnetic compensation amount of the reference flux vector is obtained, and the motor is subjected to weakening magnetic control based on the weakening magnetic compensation amount. As a result, the motor can be subjected to weakening magnetic control based on the weakening magnetic compensation amount of the reference flux vector of the motor, which can improve the response speed of the motor's weakening magnetic control and reduce the difficulty of the motor's weakening magnetic control. The device is suitable for the weakening magnetic control scenario of the motor without electrolytic capacitors.

[0156] In order to implement the above embodiment, the present invention further proposes a computer-readable storage medium storing a computer program, which implements the above-mentioned magnetic field weakening control method of the motor when executed by a processor.

[0157] The computer-readable storage medium of the embodiment of the present invention stores a computer program and is executed by a processor.

[0158] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0159] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0160] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0161] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0162] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0163] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A method for controlling a weak magnetic field of a motor, characterized in that: include: Get the initial flux vector and reference flux vector of the motor at the current moment; Obtaining a reference flux vector increment of the motor according to the initial flux vector and the reference flux vector; Predicting a flux vector increment of the motor at the next moment under each candidate switching state of the inverter; Obtaining a flux weakening compensation amount of the reference flux vector according to the reference flux vector increment and the flux vector increment of the motor at the next moment in each candidate switching state; According to the weakening magnetic compensation amount, the motor is subjected to weakening magnetic control; wherein, The obtaining of the flux weakening compensation amount of the reference flux vector according to the reference flux vector increment and the flux vector increment of the motor at the next moment in each candidate switching state includes: Obtaining a target feedback amount of the regulator according to the reference flux vector increment and the flux vector increment of the motor at the next moment in each candidate switching state; controlling the regulator to obtain the magnetic field weakening compensation amount based on the target feedback amount; The step of obtaining a target feedback amount of the regulator according to the reference flux vector increment and the flux vector increment of the motor at the next moment in each candidate switching state includes: Constructing a cost function according to the reference flux vector increment and the flux vector increment at the next moment, wherein the cost function is an absolute difference between the reference flux vector increment and the flux vector increment at the next moment; According to the reference flux vector increment and the flux vector increment of the motor at the next moment in each candidate switching state, an optimal value of the cost function is obtained, and the optimal value is used as the target feedback amount.

2. The method according to claim 1, characterized in that The step of obtaining the initial magnetic flux vector of the motor at the current moment includes: Obtaining the three-phase stator current and rotor position angle of the motor at the current moment; Obtaining a direct-axis component and a quadrature-axis component of the stator current of the motor at a current moment according to the three-phase stator current; Obtaining the rotor electrical angular velocity of the motor at a current moment according to the rotor position angle; Obtaining a direct-axis component of the initial flux vector according to the direct-axis component of the stator current and the rotor electrical angular velocity; The quadrature-axis component of the initial flux linkage vector is obtained according to the quadrature-axis component of the stator current and the rotor electrical angular velocity.

3. The method according to claim 1, characterized in that The step of obtaining a reference flux vector increment of the motor according to the initial flux vector and the reference flux vector includes: The difference between the reference flux linkage vector and the initial flux linkage vector is used as the reference flux linkage vector increment.

4. The method according to claim 1, wherein The predicting of the flux vector increment of the motor at the next moment under each candidate switching state of the inverter includes: Obtaining the DC bus voltage and rotor position angle of the motor at the current moment according to a sampling period; The flux vector increment of the motor at the next moment in any candidate switching state is predicted according to the DC bus voltage, the rotor position angle, the sampling period and any candidate switching state.

5. The method according to claim 1, wherein The optimal value is the minimum value of the cost function.

6. The method according to claim 1, characterized in that Also includes: Obtaining the DC bus voltage of the motor at the current moment according to a sampling period; Obtaining a reference value of the cost function according to the DC bus voltage and the sampling period, and using the reference value as a target reference quantity of the regulator; The controlling the regulator to obtain the magnetic field weakening compensation amount based on the target feedback amount includes: The regulator is controlled to obtain the weakening magnetic compensation amount based on the target feedback amount and the target reference amount.

7. The method according to claim 1, characterized in that Also includes: Using the candidate switching state corresponding to the optimal value as the target switching state of the inverter at the next moment; The switching state of the inverter is controlled according to the target switching state.

8. The method according to any one of claims 1 to 4, characterized in that The step of performing magnetic field weakening control on the motor according to the magnetic field weakening compensation amount includes: performing magnetic weakening compensation on the reference magnetic flux vector according to the magnetic weakening compensation amount to obtain a target reference magnetic flux vector; The motor is subjected to flux weakening control according to the target reference flux linkage vector.

9. The method according to claim 8, characterized in that The step of performing magnetic weakening compensation on the reference magnetic flux vector according to the magnetic weakening compensation amount to obtain a target reference magnetic flux vector includes: acquiring a direct-axis component of the target reference flux vector according to the flux weakening compensation amount and the direct-axis component of the reference flux vector; Obtaining the direct-axis inductance, quadrature-axis inductance, and stator current limit value of the motor; The quadrature-axis component of the target reference flux vector is obtained according to the direct-axis inductance, the quadrature-axis inductance, the stator current amplitude limit value, and the magnetic field weakening compensation amount.

10. A weak magnetic field control device for a motor, characterized in that: include: The first acquisition module is used to obtain the initial flux vector and the reference flux vector of the motor at the current moment; a second acquisition module, configured to acquire a reference flux vector increment of the motor according to the initial flux vector and the reference flux vector; A prediction module, configured to predict a flux vector increment of the motor at the next moment under each candidate switching state of the inverter; a third acquisition module, configured to acquire a flux weakening compensation amount of the reference flux vector according to the reference flux vector increment and the flux vector increment of the motor at the next moment in each candidate switching state; A control module is used to perform magnetic weakening control on the motor according to the magnetic weakening compensation amount; wherein, The third acquisition module is further configured to: Obtaining a target feedback amount of the regulator according to the reference flux vector increment and the flux vector increment of the motor at the next moment in each candidate switching state; controlling the regulator to obtain the magnetic field weakening compensation amount based on the target feedback amount; The third acquisition module is further configured to: Constructing a cost function according to the reference flux vector increment and the flux vector increment at the next moment, wherein the cost function is an absolute difference between the reference flux vector increment and the flux vector increment at the next moment; According to the reference flux vector increment and the flux vector increment of the motor at the next moment in each candidate switching state, an optimal value of the cost function is obtained, and the optimal value is used as the target feedback amount.

11. A motor, characterized in that: include: The magnetic flux weakening control device for a motor as claimed in claim 10.

12. An electronic device, characterized in that: Including memory and processor; The processor runs a program corresponding to the executable program code by reading the executable program code stored in the memory, so as to implement the magnetic field weakening control method of the motor according to any one of claims 1 to 9.

13. A computer-readable storage medium storing a computer program, characterized in that: When the program is executed by a processor, the magnetic field weakening control method of the motor according to any one of claims 1 to 9 is implemented.

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