Motor control method and device, computer readable storage medium and electronic device

Abstract

The application provides a motor control method and device, a computer readable storage medium and an electronic device. The control method comprises: obtaining a motor target torque, a current torque, a current D-axis current and a current Q-axis current, wherein the motor comprises a D-axis and a Q-axis; calculating a difference between the target torque and the current torque to obtain a torque error, and constructing a proportional integral element according to the torque error; inputting the target torque and the current torque into the proportional integral element to obtain an error current output by the proportional integral element; calculating a corrected D-axis current according to the current D-axis current and the error current, calculating a corrected Q-axis current according to the current Q-axis current and the error current, and inputting the corrected D-axis current and the corrected Q-axis current into the D-axis and the Q-axis of the motor respectively to correct the current D-axis current and the current Q-axis current. Through the application, the problem of a large workload caused by the need to obtain motor inductance parameters in the virtual signal injection method is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of motor control, in particular to a motor control method and device, a computer readable storage medium, a processor and an electronic device. BACKGROUND

[0002] In the field of motor control, the virtual signal injection method can avoid the tedious current map calibration process, but this method is easily affected by the change of motor inductance parameters. At present, there are mainly the following solutions to the problem of virtual signal injection method affected by motor parameter changes: obtaining motor parameter values under different working conditions of the motor by testing or obtaining motor parameters through online parameter identification algorithm. The above methods are to obtain motor parameters directly or indirectly to improve the performance of the virtual signal injection method. Therefore, the current mainstream method is to obtain motor parameters to solve the problem, but the direct measurement method is tedious and needs to measure motor parameters under different working conditions. The original intention of the virtual signal injection method is to avoid the calibration of the current map, and now in order to improve its performance, the motor parameters need to be retested, and the workload has not been reduced under the trade-off; in addition, the related algorithm for obtaining motor parameters through parameter identification also has its own defects, or the algorithm is too complex, increasing the operation burden of the controller, or the identified parameters are not accurate, or some parameter identification algorithms are still in the theoretical research stage. The method of obtaining motor parameters to improve the performance of the virtual signal injection method still has defects.

[0003] Therefore, there is an urgent need for a method that can solve the problem of large workload caused by obtaining motor inductance parameters in the virtual signal injection method. SUMMARY

[0004] The main purpose of the present application is to provide a motor control method and device, a computer readable storage medium, a processor and an electronic device to at least solve the problem that the virtual signal injection method in the prior art is easily affected by motor inductance parameters.

[0005] To achieve the above object, according to one aspect of the present application, a motor control method is provided, comprising: obtaining a target torque, a current torque, a current D-axis current and a current Q-axis current of a motor, wherein the motor comprises a D-axis and a Q-axis; calculating a difference between the target torque and the current torque to obtain a torque error, and constructing a proportional-integral link according to the torque error, wherein the proportional-integral link is composed of a sum of a proportional link and an integral link constructed by the torque error; inputting the target torque and the current torque into the proportional-integral link to obtain an error current output by the proportional-integral link; calculating a corrected D-axis current according to the current D-axis current and the error current, and calculating a corrected Q-axis current according to the current Q-axis current and the error current, and inputting the corrected D-axis current and the corrected Q-axis current into the D-axis and the Q-axis of the motor respectively to correct the current D-axis current and the current Q-axis current.

[0006] Optionally, constructing the proportional-integral link according to the torque error comprises: calculating a product of the torque error and a proportional constant to obtain the proportional link; calculating a product of an integral of the torque error and an integral constant to obtain the integral link; and calculating a sum of the proportional link and the integral link to obtain the proportional-integral link.

[0007] Optionally, calculating the corrected D-axis current according to the current D-axis current and the error current comprises: calculating a sum of the current D-axis current and the error current to obtain the corrected D-axis current; and calculating the corrected Q-axis current according to the current Q-axis current and the error current comprises: calculating a difference between the current Q-axis current and the error current to obtain the corrected Q-axis current.

[0008] Optionally, obtaining the current D-axis current and the current Q-axis current comprises: injecting a constant current into the D-axis and the Q-axis of the motor, and calculating the current D-axis current and the current Q-axis current by a virtual signal injection method.

[0009] Optionally, injecting a constant current into the D-axis and the Q-axis of the motor, and calculating the current D-axis current and the current Q-axis current by a virtual signal injection method comprises: injecting a constant current into the D-axis and the Q-axis of the motor to calculate a virtual output torque; calculating a first partial derivative and a second partial derivative according to the virtual output torque, wherein the first partial derivative is a partial derivative of the virtual output torque with respect to a D-axis current, and the second partial derivative is a partial derivative of the virtual output torque with respect to a Q-axis current; calculating a third partial derivative according to the first partial derivative and the second partial derivative, wherein the third partial derivative is a partial derivative of the virtual output torque with respect to a β angle; and calculating the current D-axis current and the current Q-axis current according to the second partial derivative and the third partial derivative.

[0010] Optionally, a constant current is injected into the D-axis and the Q-axis of the motor, and a virtual output torque is calculated, including: injecting the constant current into the Q-axis of the motor, and using the formula The virtual output torque corresponding to the Q-axis is calculated, wherein T e h represents the virtual output torque of the motor, A represents the constant current, i d represents the current of the D-axis of the motor, i q represents the current of the Q-axis of the motor, L d represents the inductance parameter of the D-axis of the motor, L q represents the inductance parameter of the Q-axis of the motor, n p represents the first constant, ψ f represents the electromagnetic loss of the motor; injecting the constant current into the D-axis of the motor, and using the formula The virtual output torque corresponding to the D-axis is calculated.

[0011] Optionally, according to the virtual output torque, a first partial derivative and a second partial derivative are calculated, including: according to the virtual output torque corresponding to the D-axis, using the formula The first partial derivative is calculated, wherein A represents the constant current, i d represents the current of the D-axis of the motor, i q represents the current of the Q-axis of the motor, represents the virtual output torque of the motor calculated by injecting the constant current into the D-axis of the motor, T e (i d ,i q represents the current torque of the motor, represents the partial derivative of the virtual output torque with respect to the D-axis current; according to the virtual output torque corresponding to the Q-axis, using the formula The second partial derivative is calculated, wherein represents the virtual output torque of the motor calculated by injecting the constant current into the Q-axis of the motor, represents the partial derivative of the virtual output torque with respect to the Q-axis current.

[0012] Optionally, according to the first partial derivative and the second partial derivative, a third partial derivative is calculated, including: according to the first partial derivative and the second partial derivative, using the formula The third partial derivative is calculated, wherein β represents the current vector angle, represents the partial derivative of the virtual output torque with respect to the D-axis current, represents the partial derivative of the virtual output torque with respect to the Q-axis current, denotes a partial derivative of the virtual output torque with respect to the current vector angle.

[0013] Alternatively, the current D-axis current and the current Q-axis current are calculated according to the second partial derivative and the third partial derivative, including: according to the second partial derivative and the third partial derivative, the formula The current D-axis current and the current Q-axis current are calculated, wherein T e denotes a current torque of the motor, denotes a target torque of the motor, denotes the current D-axis current, denotes the current Q-axis current.

[0014] According to another aspect of the present application, a motor control device is provided, comprising: a first obtaining unit configured to obtain a target torque of a motor, a current torque, a current D-axis current and a current Q-axis current, wherein the motor comprises a D-axis and a Q-axis; a constructing unit configured to calculate a torque error by subtracting the target torque from the current torque, and construct a proportional-integral link according to the torque error, wherein the proportional-integral link is composed of a proportional link and an integral link constructed by the torque error; a second obtaining unit configured to input the target torque and the current torque into the proportional-integral link, and obtain an error current output by the proportional-integral link; and a correcting unit configured to calculate a corrected D-axis current according to the current D-axis current and the error current, calculate a corrected Q-axis current according to the current Q-axis current and the error current, and input the corrected D-axis current and the corrected Q-axis current into the D-axis and the Q-axis of the motor respectively to correct the current D-axis current and the current Q-axis current. According to the technical solution of the present application, the target torque of the motor, the current torque, the current D-axis current and the current Q-axis current are obtained, wherein the motor comprises a D-axis and a Q-axis; a torque error is calculated by subtracting the target torque from the current torque, and a proportional-integral link is constructed according to the torque error, wherein the proportional-integral link is composed of a proportional link and an integral link constructed by the torque error; the target torque and the current torque are input into the proportional-integral link, and an error current output by the proportional-integral link is obtained; a corrected D-axis current is calculated according to the current D-axis current and the error current, a corrected Q-axis current is calculated according to the current Q-axis current and the error current, and the corrected D-axis current and the corrected Q-axis current are input into the D-axis and the Q-axis of the motor respectively to correct the current D-axis current and the current Q-axis current. Compared with the prior art, the technical solution of the present application does not need to obtain the inductance parameter of the motor, but constructs a proportional-integral link, inputs the target torque and the current torque of the motor into the proportional-integral link as inputs, and corrects the current D-axis current and the current Q-axis current calculated by the virtual signal injection method according to the error current output by the proportional-integral link, so as to correct the influence of the change of the inductance parameter of the motor, and solve the problem of large workload caused by the need to obtain the inductance parameter of the motor in the traditional virtual signal injection method. BRIEF DESCRIPTION OF DRAWINGS

[0015] The accompanying drawings, which form a part of the present description, illustrate the present application and together with the written description serve to explain the principles of the present application. In the drawings:

[0016] Figure 1A hardware structure block diagram of a mobile terminal for performing a motor control method according to an embodiment of the present application is shown.

[0017] Figure 2 A flowchart of a motor control method according to an embodiment of the present application is shown.

[0018] Figure 3 A flowchart of a specific motor control method according to an embodiment of the present application is shown.

[0019] Figure 4 A structure block diagram of a motor control apparatus according to an embodiment of the present application is shown.

[0020] 102, processor; 104, memory; 106, transmission device; 108, input / output device. DETAILED DESCRIPTION

[0021] It should be noted that the embodiments and features of the embodiments in the present application can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0022] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should fall within the scope of protection of the present application.

[0023] It should be noted that the terms "first", "second" and the like in the specification and claims of the present application and the above-described drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or a chronological sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device that includes a series of steps or units does not necessarily limit to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0024] For the convenience of description, the following describes some nouns or terms related to the embodiments of the present application:

[0025] Current Map: the expected current obtained by looking up the current speed and target torque table in the motor control process, and the table queried is the current Map.

[0026] Virtual signal injection method: an algorithm that calculates the desired current online by injecting a virtual constant current into the current.

[0027] As described in the background section, the existing virtual signal injection method requires obtaining the inductance parameters of the motor. To address the problem of the large workload caused by the virtual signal injection method requiring the acquisition of motor inductance parameters, embodiments of this application provide a motor control method, apparatus, computer-readable storage medium, processor, and electronic device.

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0029] The methods and embodiments provided in this application can be executed on a mobile terminal, computer terminal, or similar computing device. Taking running on a mobile terminal as an example, Figure 1 This is a hardware structure block diagram of a mobile terminal for a motor control method according to an embodiment of the present invention. Figure 1 As shown, a mobile terminal may include one or more ( Figure 1 Only one is shown in the diagram. A processor 102 (which may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.) and a memory 104 for storing data are also shown. The mobile terminal may further include a transmission device 106 for communication functions and an input / output device 108. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the mobile terminal described above. For example, the mobile terminal may also include components that are more... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0030] The memory 104 can be used to store computer programs, such as software programs of application software and modules, such as a computer program corresponding to the device information display method of the embodiments of the present application. The processor 102 executes various functional applications and data processing, i.e., implements the above method, by running the computer programs stored in the memory 104. The memory 104 can include a high-speed random access memory, and can further include a non-volatile memory, such as one or more magnetic storage devices, flash memories, or other non-volatile solid-state memories. In some examples, the memory 104 can further include memories disposed remotely with respect to the processor 102, which can be connected to the mobile terminal through a network. Examples of the above network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof. The transmission device 106 is used to receive or send data via a network. The specific examples of the above network can include a wireless network provided by a communication provider of the mobile terminal. In one example, the transmission device 106 includes a network adapter (NIC), which can be connected to other network devices through a base station so as to communicate with the Internet. In one example, the transmission device 106 can be a radio frequency (RF) module, which is used to communicate with the Internet in a wireless manner.

[0031] In the embodiments, a motor control method running on a mobile terminal, a computer terminal or a similar computing device is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0032] Figure 2 is a flowchart of a motor control method according to an embodiment of the present application. As shown in Figure 2 , the method includes the following steps:

[0033] In step S201, a motor target torque, a current torque, a current D-axis current and a current Q-axis current are acquired, wherein the motor includes a D-axis and a Q-axis.

[0034] Specifically, the motor generates a rotating magnetic field through an energized coil and acts on a rotor in the motor to form a magnetic electric power rotating torque, i.e., a torque of the motor. The motor is divided into a direct current motor and an alternating current motor according to different power sources, and most of the motors in the power system are alternating current motors, which can be synchronous motors or asynchronous motors (the motor stator magnetic field speed is not synchronized with the rotor rotating speed). In the control of the alternating current motor, in order to obtain the control characteristics similar to the direct current motor, a coordinate system is established on the motor rotor, the coordinate system rotates synchronously with the rotor, and the direction of the rotor magnetic field is taken as the D-axis, also called the direct axis, and the direction perpendicular to the rotor magnetic field is taken as the Q-axis, also called the quadrature axis. Therefore, the above-mentioned D-axis and Q-axis are actually coordinate axes, rather than actual axes. Converting the mathematical model of the motor into this coordinate system can realize the decoupling of the D-axis and the Q-axis, thereby obtaining good control characteristics. The target torque is the size of the torque that the motor is expected to output, and the target torque of the motor can usually be obtained and set in advance by the staff. The current torque is the actual output torque of the motor obtained by measurement. In the actual motor control process, the expected current is usually obtained according to the target torque and the current torque or the current speed, and then input to the D-axis and the Q-axis of the motor, so as to realize the control of the motor. In the prior art, the expected current is generally obtained by the current Map method, i.e., the table lookup method, or calculated by the virtual signal injection method. The current Map method has a relatively cumbersome lookup process. Therefore, in order to avoid the cumbersome table lookup process, the virtual signal injection method is generally used, and the virtual signal injection method needs to obtain the inductance parameter of the motor first. The inductance parameter is considered to accurately calculate the expected current, so as to realize the accurate control of the motor. The original intention of using the virtual signal injection method is to reduce the workload of the staff and improve the work efficiency. However, the process of obtaining the inductance parameter does not achieve the purpose of reducing the workload. The above-mentioned current D-axis current and current Q-axis current are the D-axis current and Q-axis current calculated by the virtual signal injection method without considering the influence of the inductance parameter.

[0035] In step S202, the difference between the target torque and the current torque is calculated to obtain a torque error, and a proportional integral element is constructed according to the torque error, wherein the proportional integral element is composed of the sum of a proportional element and an integral element constructed by the torque error.

[0036] Specifically, in the automatic control process, a PID control algorithm is usually adopted to achieve the purpose of automatic control, that is, control according to the proportion (P), integral (I) and differential (D) of the deviation, which is usually referred to as the proportional link, integral link and differential link. The above-mentioned deviation refers to the difference between the expected value (target value) and the actual value. In the actual control process, any combination of the above-mentioned proportional link, integral link and differential link can be selected for control according to the actual situation. For example, the difference between the expected value (target torque) and the actual value (current torque) of the motor, that is, the torque error, is used to achieve the purpose of automatically adjusting the current calculated by the virtual current injection method through the proportion (P) and integral (I) of the torque error, that is, the proportional integral (PI) link. Since PI control is a relatively mature control technology, it does not significantly increase the complexity and computational burden of the system, and has the characteristics of simplicity and easy implementation, and has broad engineering application value.

[0037] In step S203, the above-mentioned target torque and the above-mentioned current torque are input into the above-mentioned proportional integral link to obtain the error current output by the proportional integral link.

[0038] Specifically, the proportional integral link is constructed by the difference between the expected value (target torque) and the actual value (current torque), so the target torque and the current torque are input into the proportional integral link, and the output of the proportional integral link is the error current. The size of the error current value reflects the difference between the current torque (actual value) and the target torque (expected value). The current torque is the actual torque of the motor, which is inevitably affected by the inductance parameter of the motor.

[0039] In step S204, the corrected D-axis current is calculated according to the current D-axis current and the above-mentioned error current, and the corrected Q-axis current is calculated according to the current Q-axis current and the above-mentioned error current. The above-mentioned corrected D-axis current and the above-mentioned corrected Q-axis current are input into the D-axis and the Q-axis of the above-mentioned motor, respectively, to correct the above-mentioned current D-axis current and the current Q-axis current.

[0040] Specifically, since the current D-axis current and the current Q-axis current are calculated by the virtual signal injection method without considering the influence of the inductance parameter, and the error current is the current output by the proportional integral link after the target torque and the actual torque (affected by the inductance parameter) are input, the corrected D-axis current can be calculated according to the current D-axis current and the error current, and the corrected Q-axis current can be calculated according to the current Q-axis current and the error current. That is, the error current caused by the influence of the inductance parameter is indirectly obtained through the proportional integral link, and the current D-axis current and the current Q-axis current calculated by the virtual signal injection method without considering the influence of the inductance parameter are corrected. Thus, the purpose of avoiding the influence of the inductance parameter can be achieved without measuring the inductance parameter, thereby achieving the purpose of reducing the workload.

[0041] By the embodiment, a motor target torque, a current torque, a current D-axis current and a current Q-axis current are obtained, the motor includes a D-axis and a Q-axis; a torque error is calculated by the difference between the target torque and the current torque, and a proportional integral link is constructed according to the torque error, the proportional integral link is composed of a proportional link and an integral link constructed by the torque error; the target torque and the current torque are input into the proportional integral link to obtain an error current output by the proportional integral link; a corrected D-axis current is calculated according to the current D-axis current and the error current, and a corrected Q-axis current is calculated according to the current Q-axis current and the error current, and the corrected D-axis current and the corrected Q-axis current are input into the D-axis and the Q-axis of the motor respectively to correct the current D-axis current and the current Q-axis current. Compared with the prior art, the motor inductance parameter value needs to be obtained to solve the problem that the virtual signal injection method is affected by the motor inductance parameter, thereby resulting in a large amount of work. In the present application, the motor target torque and the current torque are input into the proportional integral link as the input of the proportional integral link, and the current D-axis current and the current Q-axis current calculated by the virtual signal injection method are corrected according to the error current output by the proportional integral link, so as to correct the influence of the change of the motor inductance parameter, thereby solving the problem of large amount of work caused by the need to obtain the motor inductance parameter in the traditional virtual signal injection method.

[0042] In the specific implementation process, the step S201 can be implemented by the following steps: injecting a constant current into the D-axis and the Q-axis of the motor, and calculating the current D-axis current and the current Q-axis current by the virtual signal injection method. The method calculates the current D-axis current and the current Q-axis current by the virtual signal injection method without considering the influence of inductance, so that the current D-axis current and the current Q-axis current can be further corrected.

[0043] Specifically, the virtual signal injection method can be implemented in simulation software, and a constant current A is injected into the D-axis and the Q-axis of the motor, so that the current D-axis current i d and the current Q-axis current i q .

[0044] In order to avoid the problem of heavy workload caused by the need to measure the inductance parameter, in some embodiments, a proportional integral element is constructed according to the above torque error, including: calculating the product of the above torque error and a proportional constant to obtain a proportional element; calculating the product of the integral of the above torque error and an integral constant to obtain an integral element; and calculating the sum of the above proportional element and the above integral element to obtain a proportional integral element. This method constructs a proportional integral element through the torque error, and adjusts the current calculated by the virtual signal injection method through the proportional integral element, so as to indirectly avoid the influence of the inductance parameter without measuring the inductance parameter.

[0045] Specifically, assuming that the target torque of the motor is The current torque (actual torque) is T e measured, and the torque error is The proportional integral (PI) element is Δi = K p e + K i ∫e, where K p is a proportional constant, and K i is an integral constant, which can be set by the staff according to the specific motor control scene, for example, K p = 5 and K i = 1, that is, the values of the above K p and K i are not specifically limited in the present application.

[0046] Specifically, the output of the above introduced proportional integral (PI) torque closed loop control element is superimposed on the current D-axis current and the current Q-axis current obtained by the virtual signal injection method. As long as there is an error between the current torque and the target torque, the proportional integral (PI) element can continuously adjust and output the error current, so as to improve the current distribution and ensure stable output performance even if the motor inductance parameter changes. The present application introduces a proportional integral (PI) torque closed loop control element based on the current torque of the motor, and adjusts the current distribution in real time through the torque closed loop element. First, it can solve the problem of performance degradation caused by the influence of the virtual signal injection method on the parameter; second, the entire process does not involve the motor inductance parameter problem, neither measuring the motor inductance parameter nor parameter identification, but only through the adjustment ability of the PI torque closed loop control element itself can the current be redistributed after the inductance parameter changes, ensuring the algorithm performance and output ability.

[0047] In some embodiments, the modified D-axis current is calculated according to the current D-axis current and the error current, including: calculating the sum of the current D-axis current and the error current to obtain the modified D-axis current; and the modified Q-axis current is calculated according to the current Q-axis current and the error current, including: calculating the difference between the current Q-axis current and the error current to obtain the modified Q-axis current. The method corrects the current D-axis current and the current Q-axis current by the error current, so that the error caused by the motor inductance parameter in the current calculated by the virtual signal injection method can be corrected.

[0048] Specifically, since the virtual signal injection method cannot output the target torque due to the change of the motor inductance with the increase of the current, the torque error is usually less than 0, so that the above Δi is usually less than 0. According to the bench test results, when the current increases, the current distribution is compared with the original current map, the D-axis current increases and the Q-axis current decreases. Therefore, according to the formula The current Q-axis current and the current D-axis current are corrected, wherein, is the modified Q-axis current, is the modified D-axis current. The modified Q-axis current and the modified D-axis current are input as expected currents to the Q-axis and the D-axis of the motor, so as to achieve the correction effect.

[0049] In some embodiments, a constant current is injected into the D-axis and the Q-axis of the motor, and the current D-axis current and the current Q-axis current are calculated by the virtual signal injection method, including: injecting a constant current into the D-axis and the Q-axis of the motor to calculate the virtual output torque; calculating the first partial derivative and the second partial derivative according to the virtual output torque, wherein the first partial derivative is the partial derivative of the virtual output torque with respect to the D-axis current, and the second partial derivative is the partial derivative of the virtual output torque with respect to the Q-axis current; calculating the third partial derivative according to the first partial derivative and the second partial derivative, wherein the third partial derivative is the partial derivative of the virtual output torque with respect to the β angle; and calculating the current D-axis current and the current Q-axis current according to the second partial derivative and the third partial derivative. The method calculates the current Q-axis current and the current D-axis current by the traditional virtual signal injection method to ensure that the current D-axis current and the current Q-axis current are further corrected subsequently.

[0050] In some embodiments, a constant current is injected into the D-axis and the Q-axis of the motor to calculate the virtual output torque, including: injecting the constant current into the Q-axis of the motor, and calculating the virtual output torque corresponding to the Q-axis by the formula e h wherein T represents the virtual output torque of the motor, A represents the constant current, i represents the current, and β represents the β angle. d ​represents a current of a D-axis of the motor, i q represents a current of a Q-axis of the motor, i d represents an inductance parameter of the D-axis of the motor, L q represents an inductance parameter of the Q-axis of the motor, n p represents a first constant, ψ f represents an electromagnetic loss of the motor; a constant current is injected into a D-axis of the motor, and a formula is used to calculate a virtual output torque corresponding to the D-axis.

[0051] Specifically, a constant current with a value of A is injected into the DQ axes of the motor, and virtual output torques of the D-axis and the Q-axis are respectively calculated by using a formula and a formula .

[0052] In some embodiments, according to the virtual output torques, a first partial derivative and a second partial derivative are calculated, including: according to the virtual output torque corresponding to the D-axis, a formula is used to calculate the first partial derivative, where A represents the constant current, i d represents a current of a D-axis of the motor, i q represents a current of a Q-axis of the motor, i represents a virtual output torque of the motor calculated by injecting the constant current into the D-axis of the motor, T e (i d , i q represents a current of a D-axis of the motor, i represents a partial derivative of the virtual output torque with respect to a current of the D-axis; according to the virtual output torque corresponding to the Q-axis, a formula is used to calculate the second partial derivative, where represents a virtual output torque of the motor calculated by injecting the constant current into the Q-axis of the motor, T represents a partial derivative of the virtual output torque with respect to a current of the Q-axis.

[0053] Specifically, after the virtual output torque is calculated, a Taylor expansion is performed on a torque injected with a virtual signal while ignoring a partial derivative of inductance with respect to a current, and a form of a partial derivative of the torque with respect to the DQ-axis current under a condition that the inductance is constant is obtained, that is, so as to obtain the first partial derivative and the second partial derivative. However, the above process of not considering the influence of the inductance parameter is only an ideal process, and in an actual control process, the motor is inevitably affected by the inductance parameter. When the influence of the inductance is considered, the current is represented as a function of the inductance: Under the condition of considering the influence of the inductance, the partial derivatives of the final torque with respect to the DQ-axis current can be written in the following forms: This involves the inductance-to-current bias term. The calculation and acquisition of inductance is a challenge. As mentioned in the background section, current methods solve this problem through calibration or parameter identification, which not only increases the computational load but also fails to guarantee the accuracy of the identified parameters. This application introduces a proportional-integral (PI) closed-loop control module to correct the current calculated by the virtual signal injection method, which does not consider the influence of inductance. This eliminates the need to measure the inductance parameter, indirectly correcting the impact of the inductance parameter. Therefore, the final result achieves the motor control effect described in the theoretical derivation expression considering the inductance effect.

[0054] In some embodiments, calculating the third partial derivative based on the first and second partial derivatives includes: using the formula... The third partial derivative is calculated, where β represents the current vector angle. This represents the partial derivative of the aforementioned virtual output torque with respect to the D-axis current. This represents the partial derivative of the aforementioned virtual output torque with respect to the Q-axis current. This represents the partial derivative of the virtual output torque with respect to the current vector angle. This method calculates the third partial derivative using the first and second partial derivatives, thereby achieving maximum current-to-torque ratio control of the motor.

[0055] Specifically, angle β is the vector angle of the current in the motor, used to allocate the D-axis current and Q-axis current. To achieve maximum current-to-torque ratio control, the partial derivative of the torque with respect to angle β needs to be calculated using the formula... The partial derivative of the torque with respect to angle β, i.e., the third partial derivative, can then be obtained.

[0056] In some embodiments, the current D-axis current and the current Q-axis current are calculated based on the second and third partial derivatives, including: using the formula... The current D-axis current and the aforementioned current Q-axis current are calculated, where T e This indicates the current torque of the aforementioned motor. This indicates the target torque of the aforementioned motor. This indicates the current D-axis current. This represents the current Q-axis current. The method calculates the current D-axis current and current Q-axis current using the first, second, and third partial derivatives. However, since the above calculations do not consider the influence of inductance, and the actual motor control process is inevitably affected by inductance, further corrections can be made to the current D-axis current and current Q-axis current.

[0057] In order for those skilled in the art to more clearly understand the technical solutions of the present application, the implementation process of the motor control method of the present application will be described in detail below in conjunction with specific embodiments.

[0058] The present embodiment relates to a specific motor control method, as shown in Figure 3 The present embodiment relates to a specific motor control method, as shown in

[0059] Step S1: Constant current is injected into the D-axis and Q-axis of the motor, and the current i d and the current i q are calculated by the virtual signal injection method.

[0060] Step S2: The current i d and the current i q are input as desired current into the D-axis and Q-axis, and the current input into the motor is obtained by current transformation, and the actual torque, i.e. the current torque T e is obtained by torque estimation.

[0061] Step S3: The target torque T and the current torque T e are input into the torque loop (proportional integral link), the current i d and the output of the torque loop, i.e. the error current Δi, are added to obtain the modified D-axis current i The current i q and the output of the torque loop, i.e. the error current Δi, are subtracted to obtain the modified Q-axis current i

[0062] Step S4: The modified D-axis current i and the modified Q-axis current i are input into the D-axis and Q-axis respectively to modify the current D-axis current and the current Q-axis current.

[0063] The present application also provides a motor control device, and it should be noted that the motor control device of the present application can be used to execute the motor control method provided by the present application. The device is used to implement the above embodiments and preferred embodiments, and those which have been described will not be repeated. As used below, the term "module" can be a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware, or a combination of software and hardware can also be implemented and conceived.

[0064] The motor control device provided by the present application will be described below.

[0065] Figure 4 is a schematic diagram of the motor control device according to the present application. AsFigure 4 The device comprises:

[0066] The first obtaining unit 10 is configured to obtain a motor target torque, a current torque, a current D-axis current and a current Q-axis current, wherein the motor comprises a D-axis and a Q-axis.

[0067] The constructing unit 20 is configured to calculate a torque error by subtracting the current torque from the target torque, and construct a proportional-integral link according to the torque error, wherein the proportional-integral link is composed of a proportional link and an integral link constructed by the torque error.

[0068] The second obtaining unit 30 is configured to input the target torque and the current torque into the proportional-integral link, and obtain an error current output by the proportional-integral link.

[0069] The correcting unit 40 is configured to calculate a corrected D-axis current according to the current D-axis current and the error current, calculate a corrected Q-axis current according to the current Q-axis current and the error current, and input the corrected D-axis current and the corrected Q-axis current into the D-axis and the Q-axis of the motor respectively, so as to correct the current D-axis current and the current Q-axis current.

[0070] In the specific implementation process, the first obtaining unit comprises a first calculation module configured to inject a constant current into the D-axis and the Q-axis of the motor, and calculate the current D-axis current and the current Q-axis current by a virtual signal injection method. The device calculates the current D-axis current and the current Q-axis current by the virtual signal injection method without considering the influence of inductance, so that the current D-axis current and the current Q-axis current can be further corrected.

[0071] Specifically, the virtual signal injection method can be implemented in simulation software, and a constant current A is injected into the D-axis and the Q-axis of the motor, so that the current D-axis current i d and the current Q-axis current i q .

[0072] In order to avoid the problem of large workload caused by the need to measure inductance parameters, in some embodiments, the constructing unit comprises a second calculation module, a third calculation module and a fourth calculation module, wherein the second calculation module is configured to calculate a product of the torque error and a proportional constant to obtain a proportional link; the third calculation module is configured to calculate a product of an integral of the torque error and an integral constant to obtain an integral link; and the fourth calculation module is configured to calculate a sum of the proportional link and the integral link to obtain a proportional-integral link. The device constructs the proportional-integral link by the torque error, adjusts the current calculated by the virtual signal injection method by the proportional-integral link, so as to indirectly avoid the influence of the inductance parameters without measuring the inductance parameters.

[0073] Specifically, assuming that the target torque of the motor is T By measuring, the current torque (actual torque) is T e The torque error is The proportional integral (PI) link is: Δi = K p e + K i ∫e, where K p is a proportional constant, and K i is an integral constant, which can be set by the staff according to the specific motor control scene, for example, K p = 5, K i = 1, that is, the values of K p and K i are not specifically limited in the present application.

[0074] Specifically, the proportional integral (PI) torque closed-loop control link introduced above is superimposed on the current D-axis current and the current Q-axis current obtained by the virtual signal injection method, and as long as there is an error between the current torque and the target torque, the proportional integral (PI) link can continuously adjust and output the error current, thereby achieving the effect of improving current distribution and ensuring stable output performance in the case of changes in motor inductance parameters. The present application introduces a proportional integral (PI) torque closed-loop control link based on the current torque of the motor, and adjusts the current distribution in real time through the torque closed-loop link. First, it can solve the problem of performance degradation caused by the influence of parameters on the virtual signal injection method; second, the entire process does not involve motor inductance parameters, neither measuring the motor inductance parameters nor identifying the parameters, but only through the adjustment ability of the PI torque closed-loop control link itself can the current be redistributed after the inductance parameters change, ensuring the algorithm performance and output ability.

[0075] In some embodiments, the correction unit comprises: a fifth calculation module for calculating the sum of the current D-axis current and the error current to obtain a corrected D-axis current; and a sixth calculation module for calculating the difference between the current Q-axis current and the error current to obtain a corrected Q-axis current. The device corrects the current D-axis current and the current Q-axis current by the error current, which can correct the error in the current calculated by the virtual signal injection method due to the influence of the motor inductance parameters.

[0076] Specifically, as the current increases, the virtual signal injection method cannot output the target torque due to the influence of the change in motor inductance, so the torque error is usually less than 0, and therefore Δi is usually less than 0. According to the bench test results, when the current increases, the current distribution compared to the original current Map, the D-axis current increases and the Q-axis current decreases. Therefore, according to the formula The current Q-axis current and the current D-axis current are corrected, wherein for correcting the Q-axis current, for correcting the D-axis current. The corrected Q-axis current and the corrected D-axis current are re-input as the expected current to the Q-axis and the D-axis of the motor, so as to achieve the correction effect.

[0077] In some embodiments, the first calculation module comprises a first calculation submodule, a second calculation submodule, a third calculation submodule and a fourth calculation submodule. The first calculation submodule is configured to inject a constant current into the D-axis and the Q-axis of the motor to obtain a virtual output torque. The second calculation submodule is configured to calculate a first partial derivative and a second partial derivative according to the virtual output torque, wherein the first partial derivative is the partial derivative of the virtual output torque with respect to the D-axis current, and the second partial derivative is the partial derivative of the virtual output torque with respect to the Q-axis current. The third calculation submodule is configured to calculate a third partial derivative according to the first partial derivative and the second partial derivative, wherein the third partial derivative is the partial derivative of the virtual output torque with respect to the β angle. The fourth calculation submodule is configured to calculate the current D-axis current and the current Q-axis current according to the second partial derivative and the third partial derivative. The device calculates the current Q-axis current and the current D-axis current by the conventional virtual signal injection method to ensure that the current D-axis current and the current Q-axis current are further corrected subsequently.

[0078] In some embodiments, the first calculation submodule comprises a fifth calculation submodule configured to inject the constant current into the Q-axis of the motor, and the virtual output torque corresponding to the Q-axis is calculated by the formula , wherein T e represents the output torque of the motor, T e h represents the virtual output torque of the motor, A represents the constant current, i d represents the current of the D-axis of the motor, i q represents the current of the Q-axis of the motor, L d represents the inductance parameter of the D-axis of the motor, L q represents the inductance parameter of the Q-axis of the motor, n p represents the first constant, ψ f represents the electromagnetic loss of the motor; the constant current is injected into the D-axis of the motor, and the virtual output torque corresponding to the D-axis is calculated by the formula

[0079] Specifically, a constant current with a constant A is injected into the DQ-axis of the motor, and the virtual output torques of the D-axis and the Q-axis are calculated by the formula and the formula respectively.​

[0080] In some embodiments, the second calculation sub-module comprises a sixth calculation sub-module configured to calculate the first partial derivative according to the virtual output torque corresponding to the Q-axis by using the formula wherein A represents the constant current, i d represents the current of the D-axis of the motor, i q represents the current of the Q-axis of the motor, represents the virtual output torque of the motor calculated by injecting the constant current into the D-axis of the motor, T e (i d , i q represents the current torque of the motor, represents the partial derivative of the virtual output torque with respect to the D-axis current; and the second partial derivative is calculated according to the virtual output torque corresponding to the Q-axis by using the formula wherein represents the virtual output torque of the motor calculated by injecting the constant current into the Q-axis of the motor, represents the partial derivative of the virtual output torque with respect to the Q-axis current.

[0081] Specifically, after the virtual output torque is calculated, the partial derivative of the inductance with respect to the current is ignored, and the torque injected by the virtual signal is Taylor expanded, so that a form of the partial derivative of the torque with respect to the DQ-axis current under the condition that the inductance is constant can be obtained, i.e. so as to obtain the first partial derivative and the second partial derivative. However, the above process of not considering the influence of the inductance parameter is only an ideal process. In actual control process, the motor is inevitably affected by the inductance parameter. When the influence of the inductance is considered, the current is represented as a function of the inductance: Under the condition of considering the influence of the inductance, the partial derivative of the final torque with respect to the DQ-axis current can be written in the following form: wherein the calculation and acquisition of the partial derivative term of the inductance with respect to the current is a difficulty. As mentioned in the background, the current devices solve the above problem by calibration or parameter identification. The result not only increases the calculation amount, but also cannot guarantee the accuracy of the identified parameters. Through the proportional integral link (PI closed loop control link) introduced in the present application, the current calculated by the virtual signal injection method without considering the influence of the inductance is corrected, so that the influence of the inductance parameter is indirectly corrected without measuring the value of the inductance parameter. Therefore, the control effect of the motor under the condition of considering the influence of the inductance can be finally achieved according to the theoretical derivation expression.

[0082] In some embodiments, the third calculating sub-module comprises a seventh calculating sub-module configured to calculate the third partial derivative according to the first partial derivative and the second partial derivative by using the formula wherein β represents the current vector angle, represents the partial derivative of the virtual output torque with respect to the D-axis current, represents the partial derivative of the virtual output torque with respect to the Q-axis current, represents the partial derivative of the virtual output torque with respect to the current vector angle. The device calculates the third partial derivative from the first partial derivative and the second partial derivative, thereby achieving maximum current torque ratio control of the motor.

[0083] Specifically, the β angle is the vector angle of the current in the motor, which is used to distribute the angle of the D-axis current and the Q-axis current. In order to achieve maximum current torque ratio control, the partial derivative of the torque with respect to the β angle needs to be obtained, and the formula can be used to obtain the partial derivative of the torque with respect to the β angle, i.e. the third partial derivative.

[0084] In some embodiments, the fourth calculating sub-module comprises an eighth calculating sub-module configured to calculate the current D-axis current and the current Q-axis current according to the second partial derivative and the third partial derivative by using the formula wherein T e represents the current torque of the motor, represents the target torque of the motor, represents the current D-axis current, represents the current Q-axis current. The device calculates the current D-axis current and the current Q-axis current from the first partial derivative, the second partial derivative and the third partial derivative, but since the current D-axis current and the current Q-axis current do not take into account the influence of inductance, the actual motor control process must be affected by inductance, so the current D-axis current and the current Q-axis current can be further corrected.

[0085] The motor control device comprises a processor and a memory, and the first obtaining unit, the constructing unit, the second obtaining unit and the correcting unit are all stored in the memory as program units, and the corresponding functions are realized by the processor executing the program units stored in the memory. The modules are all located in the same processor; or, the modules are located in different processors in any combination.

[0086] The processor contains a core, and the core retrieves the corresponding program unit from the memory. The core can be set to one or more, and the problem of large workload caused by the need to obtain motor inductance parameters in the virtual signal injection method can be solved by adjusting the core parameters.

[0087] The memory can include non-persistent memory in a computer readable medium, random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash memory (flash RAM), including at least one memory chip.

[0088] The embodiment of the present application provides a computer readable storage medium, the computer readable storage medium comprises a stored program, wherein the program controls a device where the computer readable storage medium is located to execute the motor control method when the program runs.

[0089] Specifically, the motor control method comprises the following steps.

[0090] In step S201, a motor target torque, a current torque, a current D-axis current and a current Q-axis current are acquired, wherein the motor comprises a D-axis and a Q-axis.

[0091] Specifically, the motor generates a rotating magnetic field through an energized coil and acts on a rotor in the motor to form a magnetic electric power rotating torque, i.e., a torque of the motor. The motor is divided into a direct current motor and an alternating current motor according to different power sources, and most of the motors in the power system are alternating current motors, which can be synchronous motors or asynchronous motors (the motor stator magnetic field speed is not synchronized with the rotor rotating speed). In the control of the alternating current motor, in order to obtain the control characteristics similar to the direct current motor, a coordinate system is established on the motor rotor, the coordinate system rotates synchronously with the rotor, and the direction of the rotor magnetic field is taken as the D-axis, also called the direct axis, and the direction perpendicular to the rotor magnetic field is taken as the Q-axis, also called the quadrature axis. Therefore, the above-mentioned D-axis and Q-axis are actually coordinate axes, rather than actual axes. Converting the mathematical model of the motor into this coordinate system can realize the decoupling of the D-axis and the Q-axis, thereby obtaining good control characteristics. The target torque is the size of the torque that the motor is expected to output, and the target torque of the motor can usually be obtained and set in advance by the staff. The current torque is the actual output torque of the motor obtained by measurement. In the actual motor control process, the expected current is usually obtained according to the target torque and the current torque or the current speed, and then input to the D-axis and the Q-axis of the motor, so as to realize the control of the motor. In the prior art, the expected current is generally obtained by the current Map method, i.e., the table lookup method, or calculated by the virtual signal injection method. The current Map method has a relatively cumbersome lookup process. Therefore, in order to avoid the cumbersome table lookup process, the virtual signal injection method is generally used, and the virtual signal injection method needs to obtain the inductance parameter of the motor first. The inductance parameter is considered to accurately calculate the expected current, so as to realize the accurate control of the motor. The original intention of using the virtual signal injection method is to reduce the workload of the staff and improve the work efficiency. However, the process of obtaining the inductance parameter does not achieve the purpose of reducing the workload. The above-mentioned current D-axis current and current Q-axis current are the D-axis current and Q-axis current calculated by the virtual signal injection method without considering the influence of the inductance parameter.

[0092] In step S202, the difference between the target torque and the current torque is calculated to obtain a torque error, and a proportional integral element is constructed according to the torque error, wherein the proportional integral element is composed of the sum of a proportional element and an integral element constructed by the torque error.

[0093] Specifically, in the automatic control process, a PID control algorithm is usually adopted to achieve the purpose of automatic control, that is, control according to the proportion (P), integral (I) and differential (D) of the deviation, which is usually referred to as the proportional link, integral link and differential link. The above-mentioned deviation refers to the difference between the expected value (target value) and the actual value. In the actual control process, any combination of the above-mentioned proportional link, integral link and differential link can be selected for control according to the actual situation. For example, the difference between the expected value (target torque) and the actual value (current torque) of the motor, that is, the torque error, is used to achieve the purpose of automatically adjusting the current calculated by the virtual current injection method through the proportion (P) and integral (I) of the torque error, that is, the proportional integral (PI) link. Since PI control is a relatively mature control technology, it does not significantly increase the complexity and computational burden of the system, and has the characteristics of simplicity and easy implementation, and has broad engineering application value.

[0094] In step S203, the target torque and the current torque are input into the proportional integral link to obtain the error current output by the proportional integral link.

[0095] Specifically, the proportional integral link is constructed by the difference between the expected value (target torque) and the actual value (current torque). Therefore, the target torque and the current torque are input into the proportional integral link, and the output of the proportional integral link is the error current. The value of the error current reflects the difference between the current torque (actual value) and the target torque (expected value). The current torque is the actual torque of the motor, which is inevitably affected by the inductance parameter of the motor.

[0096] In step S204, the corrected D-axis current is calculated according to the current D-axis current and the error current, and the corrected Q-axis current is calculated according to the current Q-axis current and the error current. The corrected D-axis current and the corrected Q-axis current are input into the D-axis and the Q-axis of the motor, respectively, to correct the current D-axis current and the current Q-axis current.

[0097] Specifically, since the current D-axis current and the current Q-axis current are calculated by the virtual signal injection method without considering the influence of the inductance parameter, and the error current is the current output by the proportional integral link after the target torque and the actual torque (affected by the inductance parameter) are input, the corrected D-axis current can be calculated according to the current D-axis current and the error current, and the corrected Q-axis current can be calculated according to the current Q-axis current and the error current. That is, the error current caused by the influence of the inductance parameter is indirectly obtained through the proportional integral link, and the current D-axis current and the current Q-axis current calculated by the virtual signal injection method without considering the influence of the inductance parameter are corrected. Thus, the purpose of avoiding the influence of the inductance parameter can be achieved without measuring the inductance parameter, thereby achieving the purpose of reducing the workload.

[0098] The embodiment of the present application provides a processor for running a program, wherein the processor is used for executing the motor control method.

[0099] Specifically, the motor control method comprises:

[0100] In step S201, a target torque of a motor, a current torque, a current D-axis current and a current Q-axis current are obtained, wherein the motor comprises a D-axis and a Q-axis.

[0101] Specifically, the motor generates a rotating magnetic field through an energized coil and acts on a rotor in the motor to form a magnetic electric power rotating torque, i.e., a torque of the motor. The motor is divided into a direct current motor and an alternating current motor according to different power sources, and most of the motors in a power system are alternating current motors, which can be synchronous motors or asynchronous motors (the motor stator magnetic field speed is not synchronized with the rotor rotating speed). In the control of the alternating current motor, in order to obtain the control characteristics similar to the direct current motor, a coordinate system is established on the motor rotor, the coordinate system rotates synchronously with the rotor, the direction of the rotor magnetic field is taken as the D-axis, also known as the direct axis, and the direction perpendicular to the rotor magnetic field is taken as the Q-axis, also known as the quadrature axis. Therefore, the D-axis and the Q-axis are actually coordinate axes, rather than actual axes. The mathematical model of the motor is converted to the coordinate system, the decoupling of the D-axis and the Q-axis is realized, and thus good control characteristics are obtained. The target torque is the size of the torque expected to be output by the motor, and the target torque of the motor can be obtained and set by a worker in advance. The current torque is the actual output torque of the motor obtained by measurement. In the actual motor control process, the expected current is generally obtained through a certain method according to the target torque and the current torque or the current speed, and the expected current is input to the D-axis and the Q-axis of the motor, so as to realize the control of the motor. In the prior art, the expected current is generally obtained directly through a current Map method, i.e., a lookup table method, or calculated through a virtual signal injection method. The lookup process of the current Map method is relatively cumbersome. Therefore, in order to avoid the cumbersome lookup process, the virtual signal injection method is generally used, and the inductance parameter of the motor needs to be obtained first. The expected current can be accurately calculated by considering the inductance parameter, so as to realize the accurate control of the motor. The original intention of using the virtual signal injection method is to reduce the workload of the worker and improve the work efficiency, but the process of obtaining the inductance parameter does not achieve the purpose of reducing the workload. The current D-axis current and the current Q-axis current are the D-axis current and the Q-axis current calculated by the virtual signal injection method without considering the influence of the inductance parameter.

[0102] In step S202, a torque error is obtained by calculating the difference between the target torque and the current torque, and a proportional integral link is constructed according to the torque error, wherein the proportional integral link is composed of the sum of a proportional link and an integral link constructed by the torque error.

[0103] Specifically, in the automatic control process, a PID control algorithm is usually adopted to achieve the purpose of automatic control, i.e. control according to the proportion (P), integral (I) and differential (D) of the deviation, which is usually referred to as the proportional link, integral link and differential link, and the above-mentioned deviation refers to the difference between the expected value (target value) and the actual value. In the actual control process, any combination of the above-mentioned proportional link, integral link and differential link can be selected for control according to the actual situation. For example, the difference between the expected value (target torque) and the actual value (current torque) of the motor, i.e. the torque error, is used to achieve the purpose of automatically adjusting the current calculated by the virtual current injection method through the proportion (P) and integral (I) of the torque error, i.e. the proportional integral (PI) link. Since PI control is a relatively mature control technology, it does not significantly increase the complexity and computational burden of the system, and has the characteristics of simplicity and easy implementation, and has broad engineering application value.

[0104] In step S203, the target torque and the current torque are input into the proportional integral link to obtain the error current output by the proportional integral link.

[0105] Specifically, the proportional integral link is constructed by the difference between the expected value (target torque) and the actual value (current torque), so the target torque and the current torque are input into the proportional integral link, and the output of the proportional integral link is the error current. The value of the error current reflects the difference between the current torque (actual value) and the target torque (expected value), and the current torque is the actual torque of the motor, which is inevitably affected by the inductance parameter of the motor.

[0106] In step S204, the corrected D-axis current is calculated according to the current D-axis current and the error current, and the corrected Q-axis current is calculated according to the current Q-axis current and the error current. The corrected D-axis current and the corrected Q-axis current are input into the D-axis and the Q-axis of the motor, respectively, to correct the current D-axis current and the current Q-axis current.

[0107] Obviously, those skilled in the art should understand that the modules or steps of the present application described above can be realized by general computing devices, which can be concentrated on a single computing device or distributed on a network composed of multiple computing devices, and they can be realized by program codes executable by the computing devices, so that they can be stored in storage devices and executed by the computing devices, and in some cases, the steps shown or described herein can be executed in different order, or they can be manufactured into individual integrated circuit modules, or multiple modules or steps thereof can be manufactured into a single integrated circuit module. Therefore, the present application is not limited to any specific combination of hardware and software.

[0108] Those skilled in the art will appreciate that embodiments of the application can be readily used as software, hardware, or a combination of software and hardware. In a typical configuration, a computing device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory.

[0109] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks.

[0110] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks.

[0111] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks.

[0112] In a typical configuration, a computing device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory.

[0113] The memory can include non-persistent memory and / or persistent memory, such as flash memory, read-only memory (ROM), and / or volatile or non-volatile random access memory (RAM), among others. The memory is an example of computer-readable media.

[0114] Computer-readable media includes permanent and non-permanent, movable and non-movable media that can be implemented by any method or technology to store information. The information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information accessible by a computing device. According to the definition herein, computer-readable media does not include transitory media such as modulated data signals and carriers.

[0115] It should also be noted that the terms "comprising", "including", or any other variant thereof are intended to cover non-exclusive inclusion, so that processes, methods, articles or devices including a series of elements not only include those elements, but also include other elements not explicitly listed, or inherent to such processes, methods, articles or devices. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0116] From the above description, it can be seen that the above-mentioned embodiments of the present application achieve the following technical effects:

[0117] 1) In the motor control method of the application, the target torque of the motor, the current torque, the current D-axis current and the current Q-axis current are obtained, wherein the motor includes a D-axis and a Q-axis; the difference between the target torque and the current torque is calculated to obtain a torque error, and a proportional integral element is constructed according to the torque error, wherein the proportional integral element is composed of the sum of the proportional element and the integral element constructed by the torque error; the target torque and the current torque are input into the proportional integral element, and the error current output by the proportional integral element is obtained; the corrected D-axis current is calculated according to the current D-axis current and the error current, and the corrected Q-axis current is calculated according to the current Q-axis current and the error current; the corrected D-axis current and the corrected Q-axis current are input into the D-axis and the Q-axis of the motor respectively to correct the current D-axis current and the current Q-axis current. Compared with the prior art, which needs to obtain the inductance parameter value of the motor to solve the problem that the virtual signal injection method is affected by the inductance parameter of the motor and thus requires a large amount of work, the application does not need to obtain the inductance parameter of the motor, but constructs a proportional integral element, inputs the target torque and the current torque of the motor into the proportional integral element as inputs of the proportional integral element, and corrects the current D-axis current and the current Q-axis current calculated by the virtual signal injection method according to the error current output by the proportional integral element, so as to achieve the purpose of correcting the influence of the change of the inductance parameter of the motor, and solve the problem of large amount of work caused by the need to obtain the inductance parameter of the motor in the traditional virtual signal injection method.

[0118] 2), the motor control method of the application, a constant current is injected into the D-axis and Q-axis of the motor, and the current D-axis and the current Q-axis are calculated by the virtual signal injection method. This method calculates the current D-axis and the current Q-axis by the virtual signal injection method without considering the influence of inductance, which can facilitate further correction of the current D-axis and the current Q-axis. Calculate the product of the torque error and the proportional constant to get the proportional link; calculate the integral of the torque error and the integral constant to get the integral link; calculate the sum of the proportional link and the integral link to get the proportional integral link. This method constructs a proportional integral link through the torque error, and adjusts the current calculated by the virtual signal injection method through the proportional integral link, so as to indirectly avoid the influence of inductance parameters without measuring inductance parameters. Calculate the sum of the current D-axis and the error current to get the corrected D-axis current; calculate the difference between the current Q-axis and the error current to get the corrected Q-axis current. In this way, the error in the current calculated by the virtual signal injection method due to the influence of motor inductance parameters can be corrected. A constant current is injected into the D-axis and Q-axis of the motor, and the virtual output torque is calculated; according to the virtual output torque, the first partial derivative and the second partial derivative are calculated; according to the first partial derivative and the second partial derivative, the third partial derivative is calculated, wherein the third partial derivative is the partial derivative of the virtual output torque with respect to the angle β; according to the second partial derivative and the third partial derivative, the current D-axis and the current Q-axis are calculated. This method calculates the current Q-axis and the current D-axis by the traditional virtual signal injection method to ensure that the current D-axis and the current Q-axis are further corrected subsequently.

[0119] The above is only the preferred embodiment of the application and is not used to limit the application. For those skilled in the art, the application can have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the application shall be included in the protection scope of the application.

Claims

1. A motor control method, characterized in that, include: The target torque, current torque, current D-axis current, and current Q-axis current of the motor are obtained, wherein the motor includes a D-axis and a Q-axis; The torque error is obtained by calculating the difference between the target torque and the current torque. Based on the torque error, a proportional-integral (PI) element is constructed, wherein the PI element is composed of the sum of the proportional element and the integral element constructed from the torque error. The target torque and the current torque are input into the proportional-integral circuit to obtain the error current output by the proportional-integral circuit. Based on the current D-axis current and the error current, the corrected D-axis current is calculated, and based on the current Q-axis current and the error current, the corrected Q-axis current is calculated. The corrected D-axis current and the corrected Q-axis current are then input into the D-axis and Q-axis of the motor, respectively, to correct the current D-axis current and the current Q-axis current. Obtain the current D-axis current and the current Q-axis current, including: A constant current is injected into the D-axis and Q-axis of the motor, and the current D-axis current and the current Q-axis current are calculated by the virtual signal injection method.

2. The control method according to claim 1, characterized in that, Based on the torque error, a proportional-integral (PI) element is constructed, including: The proportional element is obtained by multiplying the torque error by the proportional constant. The integral of the torque error is calculated and multiplied by the integral constant to obtain the integrator element; The sum of the proportional element and the integral element is calculated to obtain the proportional-integral element.

3. The control method according to claim 1, characterized in that, The corrected D-axis current is calculated based on the current D-axis current and the error current, including: calculating the sum of the current D-axis current and the error current to obtain the corrected D-axis current; The corrected Q-axis current is calculated based on the current Q-axis current and the error current, including: calculating the difference between the current Q-axis current and the error current to obtain the corrected Q-axis current.

4. The control method according to claim 1, characterized in that, A constant current is injected into the D-axis and Q-axis of the motor, and the current D-axis current and the current Q-axis current are calculated using the virtual signal injection method, including: A constant current is injected into the D-axis and Q-axis of the motor to calculate the virtual output torque; Based on the virtual output torque, a first partial derivative and a second partial derivative are calculated, wherein the first partial derivative is the partial derivative of the virtual output torque with respect to the D-axis current, and the second partial derivative is the partial derivative of the virtual output torque with respect to the Q-axis current. Based on the first and second partial derivatives, a third partial derivative is calculated, wherein the third partial derivative is the virtual output torque pair. The partial derivative of the angle, the The angle is the current vector angle; The current D-axis current and the current Q-axis current are calculated based on the second partial derivative and the third partial derivative.

5. The control method according to claim 4, characterized in that, A constant current is injected into the D-axis and Q-axis of the motor to calculate the virtual output torque, including: The constant current is injected into the Q-axis of the motor using the formula... The virtual output torque corresponding to the Q-axis is calculated, where T e h The virtual output torque of the motor is represented by A, and the constant current is represented by i. d i represents the current along the D-axis of the motor. q L represents the Q-axis current of the motor. d L represents the inductance parameter of the motor's D-axis. q n represents the inductance parameter of the Q-axis of the motor. p Denotes the first constant. This indicates the electromagnetic loss of the motor; The constant current is injected into the D-axis of the motor using the formula... The virtual output torque corresponding to the D-axis is calculated.

6. The control method according to claim 4, characterized in that, Based on the virtual output torque, the first partial derivative and the second partial derivative are calculated, including: Based on the virtual output torque corresponding to the D-axis, the formula is used. The first partial derivative is calculated, where A represents the constant current, and i d i represents the current along the D-axis of the motor. q This represents the Q-axis current of the motor. This represents the virtual output torque of the motor calculated by injecting the constant current into the D-axis of the motor. This indicates the current torque of the motor. This represents the partial derivative of the virtual output torque with respect to the D-axis current; Based on the virtual output torque corresponding to the Q-axis, the formula is used. The second partial derivative is calculated, where, This represents the virtual output torque of the motor calculated by injecting the constant current into the Q-axis of the motor. This represents the partial derivative of the virtual output torque with respect to the Q-axis current.

7. The control method according to claim 4, characterized in that, The third partial derivative is calculated based on the first and second partial derivatives, including: Based on the first partial derivative and the second partial derivative, the formula is used. The third partial derivative is calculated, where, Indicates the current vector angle. This represents the partial derivative of the virtual output torque with respect to the D-axis current. This represents the partial derivative of the virtual output torque with respect to the Q-axis current. This represents the partial derivative of the virtual output torque with respect to the current vector angle.

8. The control method according to claim 4, characterized in that, The current D-axis current and the current Q-axis current are calculated based on the second partial derivative and the third partial derivative, including: Based on the second partial derivative and the third partial derivative, the formula is used. The current D-axis current and the current Q-axis current are calculated, where, This indicates the current torque of the motor. This indicates the target torque of the motor. This indicates the current D-axis current. This indicates the current Q-axis current.

9. A motor control device, characterized in that, include: The first acquisition unit is used to acquire the target torque, current torque, current D-axis current and current Q-axis current of the motor, wherein the motor includes a D-axis and a Q-axis; A construction unit is used to calculate the difference between the target torque and the current torque to obtain the torque error, and to construct a proportional-integral (PI) element based on the torque error, wherein the PI element is composed of the sum of the proportional element and the integral element constructed from the torque error. The second acquisition unit is used to input the target torque and the current torque into the proportional-integral circuit to acquire the error current output by the proportional-integral circuit. The correction unit is used to calculate the corrected D-axis current based on the current D-axis current and the error current, and to calculate the corrected Q-axis current based on the current Q-axis current and the error current. The corrected D-axis current and the corrected Q-axis current are then input into the D-axis and Q-axis of the motor, respectively, to correct the current D-axis current and the current Q-axis current. The first acquisition unit includes: The first calculation module is used to inject a constant current into the D-axis and Q-axis of the motor, and calculate the current D-axis current and the current Q-axis current using the virtual signal injection method.

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