Motor control method and device, computer storage medium and motor driver

Abstract

The invention relates to the field of motor control, and relates to a motor control method and device, a computer storage medium and a motor driver, and the method comprises the steps: a first feedback current is a sampling current of a three-phase current at a moment before a current loop executes a control operation; the second feedback current is the sampling current of the PWM carrier center point; performing proportional processing on the direct-axis current instruction and a first direct-axis feedback current in the first feedback current, and performing integral processing on the direct-axis current instruction and a second direct-axis feedback current in the second feedback current to generate a target direct-axis voltage instruction; performing proportional processing on the quadrature-axis current instruction and a first quadrature-axis feedback current in the first feedback current, and performing integral processing on the quadrature-axis current instruction and a second quadrature-axis feedback current in the second feedback current to generate a target quadrature-axis voltage instruction; and controlling the motor to operate based on the target direct-axis voltage instruction and the target quadrature-axis voltage instruction. According to the method, the bandwidth of the current loop and the current control precision are improved.

Description

Technical Field

[0001] The present application relates to the field of motor control, and further to a motor control method, device, computer storage medium and motor driver. Background Art

[0002] Traditional current controllers generally use proportional-integral controllers, in which the proportional link and the integral link use the same feedback current. Since the dynamic characteristics of the proportional link and the integral link are different, using the same feedback current is not suitable for the dynamic characteristics of the two links, resulting in low current control accuracy. Summary of the invention

[0003] In order to solve the above technical problems, the present application provides a motor control method, device, computer storage medium and motor driver to improve the control accuracy of current.

[0004] In a first aspect, the present application provides a motor control method, including: obtaining a current command, a first feedback current, and a second feedback current of a current loop control; the current command includes a direct-axis current command and a quadrature-axis current command; the first feedback current includes a first direct-axis feedback current and a first quadrature-axis feedback current; the second feedback current includes a second direct-axis feedback current and a second quadrature-axis feedback current; the first feedback current is a sampled current of a three-phase current at a moment before the current loop performs a control operation; the second feedback current is a sampled current of a center point of a PWM carrier;

[0005] Performing proportional processing on the direct-axis current command and the first direct-axis feedback current, and performing integral processing on the direct-axis current command and the second direct-axis feedback current to generate a target direct-axis voltage command;

[0006] Performing proportional processing on the quadrature-axis current command and the first quadrature-axis feedback current, and performing integral processing on the quadrature-axis current command and the second quadrature-axis feedback current to generate a target quadrature-axis voltage command;

[0007] The operation of the motor is controlled based on the target direct-axis voltage command and the target quadrature-axis voltage command.

[0008] In the above motor control method, when performing proportional processing, the first feedback current is used to participate in the processing, for example, the first direct-axis feedback current in the direct-axis current command and the first feedback current is proportionally processed, and the first quadrature-axis feedback current in the quadrature-axis current command and the first feedback current is proportionally processed, so that the bandwidth of the current loop can be improved; when performing integral processing, the second feedback current is used to participate in the processing, for example, the second direct-axis feedback current in the direct-axis current command and the second feedback current is integrally processed, and the second quadrature-axis feedback current in the quadrature-axis current command and the second feedback current is integrally processed, so that the accuracy of current control can be improved. Finally, the motor operation is controlled according to the generated target direct-axis voltage command and the target quadrature-axis voltage command.

[0009] In one implementation, proportional processing is performed on the direct-axis current command and the first direct-axis feedback current, and integral processing is performed on the direct-axis current command and the second direct-axis feedback current to generate a target direct-axis voltage command, specifically including:

[0010] Calculating a first direct-axis current error based on a direct-axis current command and a first direct-axis feedback current;

[0011] Proportional processing is performed on the first straight-axis current error to obtain the first straight-axis voltage command;

[0012] Calculating a second direct-axis current error based on the direct-axis current command and the second direct-axis feedback current;

[0013] Integrating the second direct-axis current error to obtain a second direct-axis voltage command;

[0014] Based on the first direct-axis voltage command and the second direct-axis voltage command, a target direct-axis voltage command is generated.

[0015] In one implementation, proportional processing is performed on the quadrature-axis current command and the first quadrature-axis feedback current, and integral processing is performed on the quadrature-axis current command and the second quadrature-axis feedback current to generate a target quadrature-axis voltage command, specifically including:

[0016] Calculating a first quadrature-axis current error based on the quadrature-axis current command and the first quadrature-axis feedback current;

[0017] Proportionally processing the first quadrature-axis current error to obtain a first quadrature-axis voltage command;

[0018] Calculating a second quadrature-axis current error based on the quadrature-axis current command and the second quadrature-axis feedback current;

[0019] Integrating the second quadrature-axis current error to obtain a second quadrature-axis voltage command;

[0020] A target quadrature-axis voltage command is generated based on the first quadrature-axis voltage command and the second quadrature-axis voltage command.

[0021] In one implementation, the steps of sampling the first feedback current and the second feedback current include:

[0022] Acquire the three-phase current at a first sampling moment based on the first trigger signal, and acquire the three-phase fundamental current at a second sampling moment based on the second trigger signal, wherein the first sampling moment is the moment before the current loop performs the control operation, and the second sampling moment is the moment corresponding to the center point of the PWM carrier;

[0023] latching the position information of the motor at the third sampling moment based on the third trigger signal;

[0024] Performing coordinate transformation on the three-phase current based on the position information, the third triggering moment of the third triggering signal, the third sampling moment, the first triggering moment of the first triggering signal, and the first sampling moment to obtain a first feedback current;

[0025] Based on the position information, the third triggering moment, the third sampling moment, the second triggering moment and the second sampling moment of the second triggering signal, coordinate transformation is performed on the three-phase fundamental current to obtain the second feedback current.

[0026] In one implementation, the position information includes an angle and an angular velocity; performing coordinate transformation on the three-phase current based on the position information, the third triggering moment of the third trigger signal, the third sampling moment, the first triggering moment of the first trigger signal, and the first sampling moment to obtain the first feedback current specifically includes:

[0027] Calculating a first compensation angle based on the angular velocity, the third triggering moment, the third sampling moment, the first triggering moment, and the first sampling moment;

[0028] Calculating a first electrical angle based on the first compensation angle and the angle;

[0029] The three-phase current is subjected to coordinate transformation based on the first electrical angle to obtain a first feedback current.

[0030] In one implementation, the position information includes an angle and an angular velocity; based on the position information, the third triggering moment, the third sampling moment, the second triggering moment of the second triggering signal, and the second sampling moment, coordinate transformation is performed on the three-phase fundamental current to obtain the second feedback current, specifically including:

[0031] Calculating a second compensation angle based on the angular velocity, the third triggering moment, the third sampling moment, the second triggering moment, and the second sampling moment;

[0032] Calculating a second electrical angle based on the second compensation angle and the angle;

[0033] The coordinate transformation of the three-phase fundamental current is performed based on the second electrical angle to obtain the second feedback current.

[0034] In one implementation, it also includes: when the sampling moment corresponding to the three-phase current is after the preset switching tube moment, and the time interval between the sampling moment corresponding to the three-phase current and the switching tube moment is less than the time threshold, the sampling moment corresponding to the three-phase current is moved forward.

[0035] In a second aspect, the present application further provides a motor control device, the device comprising:

[0036] An acquisition module is used to acquire a current instruction, a first feedback current, and a second feedback current of a current loop control; the current instruction includes a direct-axis current instruction and a quadrature-axis current instruction; the first feedback current includes a first direct-axis feedback current and a first quadrature-axis feedback current; the second feedback current includes a second direct-axis feedback current and a second quadrature-axis feedback current; the first feedback current is a sampling current of the three-phase current at a moment before the current loop performs a control operation; the second feedback current is a sampling current of a center point of a PWM carrier;

[0037] A proportional module, used for performing proportional processing on the direct-axis current command and the first direct-axis feedback current, and performing integral processing on the direct-axis current command and the second direct-axis feedback current, so as to generate a target direct-axis voltage command;

[0038] an integral module, used for performing proportional processing on the quadrature-axis current command and the first quadrature-axis feedback current, and performing integral processing on the quadrature-axis current command and the second quadrature-axis feedback current, so as to generate a target quadrature-axis voltage command;

[0039] The control module is used to control the operation of the motor based on the target direct-axis voltage command and the target quadrature-axis voltage command.

[0040] In a third aspect, the present application further provides a computer storage medium on which a computer program is stored, and when the computer program is executed by a processor, any of the steps of the above motor control method is implemented.

[0041] In a fourth aspect, the present application further provides a motor driver, comprising a memory and a processor, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, any of the steps of the above motor control method is implemented.

[0042] Compared with the prior art, the present invention has the following beneficial effects: a target direct-axis voltage command is generated by proportionally processing the direct-axis current command and the first direct-axis feedback current in the current command controlled by the current loop, and integrating the direct-axis current command and the second direct-axis feedback current; a target quadrature-axis voltage command is generated by proportionally processing the quadrature-axis current command and the first quadrature-axis feedback current in the current command controlled by the current loop, and integrating the quadrature-axis current command and the second quadrature-axis feedback current; based on the target direct-axis voltage command and the target quadrature-axis voltage command, the motor operation is controlled, that is, in the proportional link, the sampled current of the three-phase current at the moment before the current loop performs the control operation is used as the first feedback current, and in the integral link, the sampled current of the center point of the PWM carrier is used as the second feedback current, which meets the dynamic characteristics of the proportional link and the integral link, thereby improving the control accuracy of the current. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The preferred implementation modes will be described below in a clear and understandable manner with reference to the accompanying drawings to further illustrate the above-mentioned characteristics, technical features, advantages and implementation methods of the present invention.

[0044] Figure 1 A schematic diagram of a topological structure of a motor driver provided in an embodiment of the present application is shown;

[0045] Figure 2 A timing diagram for obtaining three-phase fundamental current provided by an embodiment of the present application is shown;

[0046] Figure 3 A timing diagram for obtaining the three-phase current at a moment before the current loop performs a control operation provided by an embodiment of the present application is shown;

[0047] Figure 4 A schematic diagram showing the operation of a proportional-integral controller provided in an embodiment of the present application is shown;

[0048] Figure 5 A flow chart of a motor control method provided by an embodiment of the present application is shown;

[0049] Figure 6 A flow chart of generating a target direct-axis voltage instruction provided by an embodiment of the present application is shown;

[0050] Figure 7 A flow chart of generating a target quadrature-axis voltage instruction provided by an embodiment of the present application is shown;

[0051] Figure 8 A schematic diagram showing a working process of a proportional-integral controller provided in an embodiment of the present application to generate a target direct-axis voltage command and a target quadrature-axis voltage command is shown;

[0052] Fig. 9A flow chart of obtaining a first feedback current and a second feedback current provided in an embodiment of the present application is shown;

[0053] Fig.10 A timing diagram of a sampling moment provided by an embodiment of the present application is shown;

[0054] Fig.11 A flow chart of performing coordinate transformation on three-phase current to obtain a first feedback current provided by an embodiment of the present application is shown;

[0055] Fig.12 A flow chart of performing coordinate transformation on a three-phase fundamental current to obtain a second feedback current provided by an embodiment of the present application is shown;

[0056] Fig.13 A timing diagram of a sampling point affected by ringing noise provided by an embodiment of the present application is shown;

[0057] Fig.14 A timing diagram of a sampling point avoiding the influence of ringing noise provided by an embodiment of the present application is shown;

[0058] Fig.15 A schematic diagram of the topological structure of another motor driver provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0059] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings and other implementation methods can be obtained based on these drawings without creative work.

[0060] In order to simplify the drawings, only the parts related to the invention are schematically shown in each figure, and they do not represent the actual structure of the product. In addition, in order to simplify the drawings and facilitate understanding, in some figures, only one of the parts with the same structure or function is schematically drawn or marked. In this article, "one" not only means "only one", but also means "more than one".

[0061] It should be further understood that the term “and / or” used in the specification and appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0062] In this document, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0063] In addition, in the description of the present application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0064] It should be noted that the above embodiments can be freely combined as needed. The above are only preferred embodiments of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

[0065] A motor driver is a power electronic device that receives control signals and converts them into appropriate current and voltage to drive the motor to run at a predetermined speed, torque, and direction. Motor drivers usually include key components such as power input, rectifier, filter, inverter, controller, and protection circuit to achieve precise control of the motor. It ensures efficient and stable operation of the motor through built-in control algorithms such as pulse width modulation (PWM) technology, as well as current, speed, and position feedback systems. Motor drivers are widely used in many fields such as industrial automation, electric vehicles, home appliances, and medical equipment, and are an indispensable part of modern motor control systems.

[0066] The controller in the motor driver can be a proportional-integral controller (or PI controller). In the process of controlling the motor, in order to improve the control performance of the motor, it is necessary to decouple the motor in the rotor coordinate system in terms of the direct axis (D axis) / quadrature axis (Q axis), and use two proportional-integral controllers to control the direct axis feedback current and the quadrature axis feedback current respectively. Among them, the direct axis feedback current and the quadrature axis feedback current can be obtained by sampling the motor current through a two-phase / three-phase current sampling module, and performing coordinate conversion on the sampled current. The two proportional-integral controllers generate a direct axis voltage command and a quadrature axis voltage command based on the direct axis feedback current and the quadrature axis feedback current, respectively, and then process the obtained direct axis voltage command and the quadrature axis voltage command accordingly to control the operation of the motor.

[0067] The following is explained with reference to the accompanying drawings:

[0068] Reference Figure 1, which shows a schematic diagram of the topological structure of a motor driver provided in an embodiment of the present application. Figure 1 As shown, it includes: direct axis current controller (refer to the attached Figure 1 The current controller (D axis) is used to Figure 1 D-axis current command) and direct-axis feedback current (refer to Appendix Figure 1 D-axis feedback current) to generate the direct-axis voltage command (refer to the attached Figure 1 D-axis voltage command); quadrature-axis current controller (refer to Appendix Figure 1 The current controller (Q axis) is used to Figure 1 Q axis current command) and quadrature axis feedback current (refer to Appendix Figure 1 Q axis feedback current) to generate the quadrature axis voltage command (refer to the attached Figure 1 The current sampling module is used to obtain the three-phase current; the angle calculation module is used to calculate the Park transformation electrical angle and the reverse Park transformation electrical angle according to the motor rotor position; the Clark / Park transformation module (or Clark / Park transformation module) is used to convert the three-phase current into the direct-axis feedback current and the quadrature-axis feedback current; the reverse Park / Clark transformation module is used to convert the direct-axis voltage command and the quadrature-axis voltage command into the Alpha-axis voltage command and the Beta-axis voltage command; the PWM modulation module is used to convert the Alpha-axis voltage command and the Beta-axis voltage command into 6-channel PWM signals, and adjust the output of the inverter (or adjust the switching state of the inverter) through the 6-channel PWM signals, thereby controlling the operation of the motor.

[0069] The current flowing into the motor through the inverter is actually a current in the form of a PWM carrier. Therefore, in order to improve the current control accuracy, the direct-axis current controller and the quadrature-axis current controller can process the sampled current at the center point of the PWM carrier (where the sampled current at the center point of the PWM carrier is obtained by Clark / Park transformation of the three-phase fundamental current at the corresponding moment of the PWM carrier center point). Therefore, the current sampling module needs to obtain the three-phase fundamental current at the corresponding moment of the PWM carrier center point. For details, please refer to the attached Figure 2 A timing diagram for obtaining three-phase fundamental current is shown in FIG. Although this method can improve the control accuracy of the current, it limits the bandwidth of the current loop due to the large sampling delay.

[0070] There are many ways to increase the bandwidth of the current loop. For example, the sampling delay can be reduced so that the direct-axis current controller and the quadrature-axis current controller process the sampled current of the three-phase current at the moment before the current loop performs the control operation (wherein the sampled current is obtained by performing Clark / Park transformation on the three-phase current at the moment before the current loop performs the control operation). Therefore, the current sampling module needs to obtain the three-phase current at the moment before the current loop performs the control operation (that is, the latest three-phase current before the current loop performs the control operation, and the three-phase current obtained at this time contains fundamental current and ripple current). For details, please refer to the attached Figure 3 A timing diagram of obtaining the three-phase current at the moment before the current loop performs a control operation is shown, wherein the current loop performs a control operation which can also be called a current loop calculation. Although this method can improve the bandwidth of the current loop, it will also reduce the control accuracy of the current and introduce medium and low frequency harmonics in the current control, affecting the quality of the current control.

[0071] Both the direct-axis current controller and the quadrature-axis current controller are proportional-integral controllers, which include proportional and integral links. Figure 4 A schematic diagram of a proportional-integral controller operation is shown. In order to improve the control accuracy of the current and the bandwidth of the current loop, the proportional link and the integral link can be processed separately, that is, the proportional link and the integral link respectively process the feedback current calculated by different filter parameters. For example, if the current sampling module is a Σ-Δ type filter and obtains the three-phase current of the motor, the three-phase current is subjected to coordinate transformation (or Clark / Park transformation) in the Park / Clark transformation module to obtain the corresponding feedback current. The feedback current obtained by the coordinate transformation can include the feedback current of low decimation rate filtering (that is, the decimation rate corresponding to the feedback current is less than the first threshold) and the feedback current of high decimation rate filtering (that is, the decimation rate corresponding to the feedback current is not less than the first threshold). The feedback current of low decimation rate filtering can be proportionally processed in the proportional link, thereby reducing the sampling delay. The feedback current of high decimation rate filtering can be integrated in the integral link to improve the sampling accuracy. This method can improve the control performance to a certain extent, but it still cannot completely balance the requirements of controlling the bandwidth of the current loop and controlling the current accuracy.

[0072] The embodiment of the present application improves the bandwidth of the current loop by proportionally processing the sampled current of the three-phase current at a moment before the current loop executes the control operation; and integrates the sampled current at the center point of the PWM carrier to improve the control accuracy of the current.

[0073] For example, see Attachment Figure 5 , which shows a flow chart of a motor control method provided by an embodiment of the present application. Figure 5 As shown, including:

[0074] S500, obtaining the current command, the first feedback current and the second feedback current of the current loop control; the current command includes the direct-axis current command and the quadrature-axis current command; the first feedback current includes the first direct-axis feedback current and the first quadrature-axis feedback current; the second feedback current includes the second direct-axis feedback current and the second quadrature-axis feedback current; the first feedback current is the sampling current of the three-phase current at the moment before the current loop performs the control operation; the second feedback current is the sampling current of the center point of the PWM carrier.

[0075] S510, performing proportional processing on the direct-axis current command and the first direct-axis feedback current, and performing integral processing on the direct-axis current command and the second direct-axis feedback current, so as to generate a target direct-axis voltage command.

[0076] S520, performing proportional processing on the quadrature-axis current command and the first quadrature-axis feedback current, and performing integral processing on the quadrature-axis current command and the second quadrature-axis feedback current, so as to generate a target quadrature-axis voltage command.

[0077] S530, controlling the operation of the motor based on the target direct-axis voltage command and the target quadrature-axis voltage command.

[0078] The three-phase current at the moment before the current loop performs the control operation and the three-phase fundamental current at the moment corresponding to the center point of the PWM carrier are obtained. The three-phase current at the moment before the current loop performs the control operation is subjected to coordinate transformation (or Clark / Park transformation) to obtain the first direct-axis feedback current and the first quadrature-axis feedback current, and the three-phase fundamental current at the moment corresponding to the center point of the PWM carrier is subjected to coordinate transformation to obtain the second direct-axis feedback current and the second quadrature-axis feedback current. Then, the direct-axis current command and the first direct-axis feedback current are proportionally processed, and the direct-axis current command and the second direct-axis feedback current are integrally processed to generate a target direct-axis voltage command. The quadrature-axis current command and the first quadrature-axis feedback current are proportionally processed, and the quadrature-axis current command and the second quadrature-axis feedback current are integrally processed to generate a target quadrature-axis voltage command.

[0079] Furthermore, the target direct-axis voltage command and the target quadrature-axis voltage command are respectively subjected to inverse coordinate transformation (or inverse Park / Clark transformation) to be converted into corresponding Alpha-axis voltage command and Beta-axis voltage command. The Alpha-axis voltage command and Beta-axis voltage command are converted into multiple PWM signals (in the embodiment of the present application, 6 PWM signals can be used), and the output of the inverter is adjusted through the multiple PWM signals to control the operation of the motor.

[0080] In the embodiment of the present application, when performing proportional processing, the first feedback current is used to participate in the processing, for example, the first direct-axis feedback current in the direct-axis current command and the first feedback current is proportionally processed, and the first quadrature-axis feedback current in the quadrature-axis current command and the first feedback current is proportionally processed, so that the bandwidth of the current loop can be improved; when performing integral processing, the second feedback current is used to participate in the processing, for example, the second direct-axis feedback current in the direct-axis current command and the second feedback current is integrally processed, and the second quadrature-axis feedback current in the quadrature-axis current command and the second feedback current is integrally processed, so that the accuracy of current control can be improved. At the same time, medium and low-frequency harmonics will not be introduced in the current control, which improves the quality of current control. Finally, the motor operation is controlled according to the generated target direct-axis voltage command and target quadrature-axis voltage command.

[0081] Reference Figure 6 , which shows a flow chart of generating a target direct-axis voltage instruction provided by an embodiment of the present application. Figure 6 As shown, the direct-axis current command and the first direct-axis feedback current are proportionally processed, and the direct-axis current command and the second direct-axis feedback current are integrally processed to generate a target direct-axis voltage command, specifically including:

[0082] S600, calculating a first direct-axis current error based on the direct-axis current command and the first direct-axis feedback current.

[0083] S610, performing proportional processing on the first straight-axis current error to obtain a first straight-axis voltage command.

[0084] S620, calculating a second direct-axis current error based on the direct-axis current command and the second direct-axis feedback current.

[0085] S630, integrating the second direct-axis current error to obtain a second direct-axis voltage command.

[0086] S640: Generate a target direct-axis voltage command based on the first direct-axis voltage command and the second direct-axis voltage command.

[0087] The process of generating the target quadrature-axis voltage command is similar to that of generating the target direct-axis voltage command. Figure 7 , which shows a flow chart of generating a target quadrature-axis voltage instruction provided by an embodiment of the present application. Figure 7 As shown, the quadrature-axis current command and the first quadrature-axis feedback current are proportionally processed, and the quadrature-axis current command and the second quadrature-axis feedback current are integrally processed to generate a target quadrature-axis voltage command, specifically including:

[0088] S700, calculating a first quadrature-axis current error based on the quadrature-axis current command and the first quadrature-axis feedback current.

[0089] S710, performing proportional processing on the first quadrature-axis current error to obtain a first quadrature-axis voltage command.

[0090] S720, calculating a second quadrature-axis current error based on the quadrature-axis current command and the second quadrature-axis feedback current.

[0091] S730, integrating the second quadrature-axis current error to obtain a second quadrature-axis voltage command.

[0092] S740: Generate a target quadrature-axis voltage command based on the first quadrature-axis voltage command and the second quadrature-axis voltage command.

[0093] After the coordinate transformation of the three-phase current at the moment before the current loop performs the control operation to obtain the first direct-axis feedback current and the first quadrature-axis feedback current, and the coordinate transformation of the three-phase fundamental current at the moment corresponding to the center point of the PWM carrier to obtain the second direct-axis feedback current and the second quadrature-axis feedback current, the first direct-axis current error is calculated based on the current value carried in the direct-axis current command and the first direct-axis feedback current, and the first direct-axis current error is proportionally processed to obtain the first direct-axis voltage command. The second direct-axis current error is calculated based on the current value carried in the direct-axis current command and the second direct-axis feedback current, and the second direct-axis current error is integrated to obtain the second direct-axis voltage command. Then, the target direct-axis voltage command is generated according to the first direct-axis voltage command and the second direct-axis voltage command.

[0094] Similarly, based on the current value carried in the quadrature-axis current command and the first quadrature-axis feedback current, the first quadrature-axis current error is calculated, and the first quadrature-axis current error is proportionally processed to obtain the first quadrature-axis voltage command. Based on the current value carried in the quadrature-axis current command and the second quadrature-axis feedback current, the second quadrature-axis current error is calculated, and the second quadrature-axis current error is integrated to obtain the second quadrature-axis voltage command. Then, based on the first quadrature-axis voltage command and the second quadrature-axis voltage command, a target quadrature-axis voltage command is generated. Among them, the working schematic diagram of generating the target direct-axis voltage command and the target quadrature-axis voltage command by the proportional-integral controller can be referred to in the attached figure. Figure 8 .

[0095] Furthermore, the target direct-axis voltage command and the target quadrature-axis voltage command are respectively transformed into corresponding alpha-axis voltage command and beta-axis voltage command. The alpha-axis voltage command and beta-axis voltage command are converted into multiple PWM signals, and the output of the inverter is adjusted by the multiple PWM signals to control the operation of the motor.

[0096] Reference Fig. 9 , which shows a flow chart of obtaining a first feedback current and a second feedback current provided by an embodiment of the present application. Fig. 9 As shown, including:

[0097] S900, obtaining the three-phase current at a first sampling moment based on the first trigger signal, and obtaining the three-phase fundamental current at a second sampling moment based on the second trigger signal, wherein the first sampling moment is the moment before the current loop performs a control operation, and the second sampling moment is the moment corresponding to the center point of the PWM carrier.

[0098] S910, latching the position information of the motor at a third sampling time based on a third trigger signal.

[0099] S920, performing coordinate transformation on the three-phase current based on the position information, the third triggering moment of the third triggering signal, the third sampling moment, the first triggering moment of the first triggering signal, and the first sampling moment to obtain a first feedback current.

[0100] S930, performing coordinate transformation on the three-phase fundamental current based on the position information, the third triggering moment, the third sampling moment, the second triggering moment and the second sampling moment of the second triggering signal to obtain a second feedback current.

[0101] There will be a delay when a trigger signal is received and when the corresponding operation is started based on the trigger signal, that is, each trigger signal has a corresponding trigger time and sampling time. Fig.10 , attached Fig.10 A is the time when the current loop performs the control operation, B is the third triggering time (or the time when the trigger position is latched), C is the third sampling time, D is the second triggering time, E is the second sampling time (or the time corresponding to the center point of the PWM carrier), F is the first triggering time, and G is the first sampling time. T1 is the time interval between the third triggering time and the first triggering time, T2 is the time interval between the third triggering time and the second triggering time, T3 is the time interval between the first triggering time and the time when the current loop performs the control operation, T4 is the time interval between the first triggering time and the first sampling time, T5 is the time interval between the second triggering time and the second sampling time, and T6 is the time interval between the third triggering time and the third sampling time.

[0102] The first trigger signal, the second trigger signal and the third trigger signal can be preset according to user needs. The sampling moments corresponding to the second trigger signal and the third trigger are fixed, while the sampling moment corresponding to the first trigger signal can be adjusted within the time range before the current loop performs the control operation.

[0103] The three-phase current at the first sampling moment is acquired based on the first trigger signal, and the three-phase fundamental current at the second sampling moment is acquired based on the second trigger signal. The position information of the motor at the third sampling moment is latched based on the third trigger signal.

[0104] First, based on the position information, the third triggering moment, the third sampling moment, the first triggering moment and the first sampling moment, a first electrical angle is generated; and based on the position information, the third triggering moment, the third sampling moment, the second triggering moment and the second sampling moment, a second electrical angle is generated. Then, based on the first electrical angle, the three-phase current at the first sampling moment is transformed into a coordinate to obtain a first feedback current; based on the second electrical angle, the three-phase fundamental current at the second sampling moment is transformed into a coordinate to obtain a second feedback current.

[0105] Since the first feedback current includes the first direct-axis feedback current and the first quadrature-axis feedback current, and the second feedback current includes the second direct-axis feedback current and the second quadrature-axis feedback current, the processing flow is the same as the aforementioned embodiment, the direct-axis current command and the first direct-axis feedback current are proportionally processed, and the direct-axis current command and the second direct-axis feedback current are integrally processed to generate a target direct-axis voltage command; the quadrature-axis current command and the first quadrature-axis feedback current are proportionally processed, and the quadrature-axis current command and the second quadrature-axis feedback current are integrally processed to generate a target quadrature-axis voltage command, and the detailed flow is not repeated here.

[0106] Reference Fig.11 , which shows a flow chart of performing coordinate transformation on three-phase current to obtain the first feedback current provided by an embodiment of the present application. Fig.11 As shown, based on the position information, the third triggering moment of the third triggering signal, the third sampling moment, the first triggering moment of the first triggering signal and the first sampling moment, the three-phase current is transformed into a coordinate to obtain the first feedback current, specifically including:

[0107] S1100, calculating a first compensation angle based on the angular velocity, the third triggering moment, the third sampling moment, the first triggering moment and the first sampling moment.

[0108] S1110, calculating a first electrical angle based on a first compensation angle and an angle.

[0109] S1120, performing coordinate transformation on the three-phase current based on the first electrical angle to obtain a first feedback current.

[0110] The process of converting the three-phase fundamental current into the second feedback current is similar to the process of converting the three-phase current into the first feedback current. Fig.12 , which shows a flow chart of performing coordinate transformation on the three-phase fundamental current to obtain the second feedback current provided by an embodiment of the present application. Fig.12 As shown, based on the position information, the third triggering moment, the third sampling moment, the second triggering moment and the second sampling moment of the second trigger signal, coordinate transformation is performed on the three-phase fundamental current to obtain the second feedback current, specifically including:

[0111] S1200, calculating a second compensation angle based on the angular velocity, the third triggering moment, the third sampling moment, the second triggering moment and the second sampling moment.

[0112] S1210, calculating a second electrical angle based on a second compensation angle and an angle.

[0113] S1230, performing coordinate transformation on the three-phase fundamental current based on the second electrical angle to obtain a second feedback current.

[0114] Position information includes angle and angular velocity. When calculating the electrical angle, it is first necessary to calculate the compensation angle of each electrical angle. The calculation of the compensation angle needs to be based on the time interval between each trigger moment and the sampling moment. For example, when calculating the first electrical angle, determine the time interval T1 between the third trigger moment and the first trigger moment, the time interval T4 between the first trigger moment and the first sampling moment, and the time interval T6 between the third trigger moment and the third sampling moment. Then, substitute T1, T4, T6 and the angular velocity into the formula to obtain the first compensation angle. The specific formula is: Δθ1=(T1-T6+T4)·ω. Where ω is the angular velocity in rad / s. Further substitute the first compensation angle Δθ1 and the angle into the formula to obtain the first electrical angle. The specific formula is: θ1=θ+Δθ1, where θ is the angle. Then, based on the first electrical angle, the three-phase current at the first sampling moment is transformed into coordinates to obtain the first feedback current.

[0115] Similarly, when calculating the second electrical angle, determine the time interval T2 between the third trigger moment and the second trigger moment, the time interval T5 between the second trigger moment and the second sampling moment, and the time interval T6 between the third trigger moment and the third sampling moment. Then, substitute T2, T5, T6 and the angular velocity into the formula to obtain the second compensation angle. The specific formula is: Δθ2 = (T2-T6+T5)·ω. Further substitute the first compensation angle Δθ2 and the angle into the formula to obtain the second electrical angle. The specific formula is: θ2 = θ+Δθ2. Then, based on the second electrical angle, the three-phase fundamental current at the second sampling moment is transformed into coordinates to obtain the second feedback current.

[0116] Further, after obtaining the first feedback current and the second feedback current, the process of generating the target direct-axis voltage command and the target quadrature-axis voltage command based on the direct-axis current command, the quadrature-axis current command, the first direct-axis feedback current and the first quadrature-axis feedback current in the first feedback current, and the second direct-axis feedback current and the second quadrature-axis feedback current in the second feedback current is the same as the aforementioned embodiment and will not be repeated here.

[0117] In the embodiment of the present application, based on the position information, each triggering moment and each sampling moment, the calculated electrical angle can perform angle compensation on the three-phase current at the first sampling moment and the three-phase fundamental current at the second sampling moment, thereby achieving accurate coordinate conversion and obtaining accurate first feedback current and second feedback current. This process can effectively improve the accuracy of current feedback, provide more reliable input data for subsequent proportional processing and integral processing, and thus improve the control performance and stability of the entire system.

[0118] In one embodiment of the present application, it also includes: when the sampling moment corresponding to the three-phase current is after the preset switching tube moment, and the time interval between the sampling moment corresponding to the three-phase current and the switching tube moment is less than the time threshold, the sampling moment corresponding to the three-phase current is moved forward.

[0119] The sampling moment corresponding to the three-phase current is the first sampling moment. When the first sampling moment is after the preset switching moment (the preset switching moment or the power device switching moment), and the time interval between the first sampling moment and the preset switching moment is less than the time threshold, the three-phase current obtained at this time will be affected by the ringing noise, thereby causing greater current noise. For details, please refer to the attached Fig.13 A timing diagram showing a sampling point affected by ringing noise.

[0120] Therefore, in order to reduce the influence of ringing noise, when the first sampling moment is after the preset switching moment, and the time interval between the first sampling moment and the preset switching moment is less than the time threshold, the first sampling moment is advanced so as to obtain the three-phase current before the preset switching moment. For details, please refer to the attached Fig.14 A timing diagram showing a sampling point avoiding the influence of ringing noise. If the first sampling moment is before the preset switching tube moment, or the first sampling moment is after the preset switching tube moment, but the time interval between the first sampling moment and the preset switching tube moment is not less than the time threshold, the first sampling moment is kept unchanged. Among them, the time threshold is set according to the influence time of the ringing noise. If the three-phase current is obtained by a Σ-Δ type analog-to-digital converter, the time threshold is also related to the order and sampling rate of the filter in the Σ-Δ type analog-to-digital converter.

[0121] In the embodiment of the present application, when the first sampling moment is determined to be after the preset switch moment, and the time interval between the first sampling moment and the switch moment is less than the time threshold, it indicates that the three-phase current sampled at the first sampling moment may be affected by the ringing noise. Therefore, it is necessary to move the first sampling moment forward, which can effectively reduce the impact of the ringing noise on the three-phase current and improve the anti-interference ability of the entire system.

[0122] Reference Fig.15, which shows a schematic diagram of the topological structure of another motor driver provided in an embodiment of the present application. The motor control method in the above embodiment is applied in the motor driver. Fig.15 As shown, it includes: direct axis current controller (refer to the attached Fig.15 Medium current controller (D axis)), quadrature axis current controller (refer to Appendix Fig.15 Current controller (Q axis)), angle calculation module (refer to the attached Figure 7 The angle calculation in the first Clark / Park transformation module (see Appendix Fig.15 Clark / Park transformation 1), the second Clark / Park transformation module (refer to the attached Fig.15 Clark / Park transformation 2), the first current sampling module (refer to the attached Fig.15 Current sampling 1), the second current sampling module (refer to the attached Fig.15 Current sampling 2), position latch module (refer to the attached Fig.15 Position latch in the), timing trigger module (refer to the attached Fig.15 timing trigger in ).

[0123] The timing trigger module is used to set the first trigger signal, the second trigger signal and the third trigger signal (see Appendix Fig.15 The first current sampling module is configured to obtain the three-phase current at the first sampling moment based on the first trigger signal (refer to the attached Fig.15 The second current sampling module is configured to obtain the three-phase fundamental current at the second sampling moment based on the second trigger signal (refer to the attached Fig.15 The position latch module is configured to latch the position information of the motor based on the third trigger signal. The angle calculation module is configured to calculate the first compensation angle based on the angular velocity, the third trigger moment, the third sampling moment, the first trigger moment and the first sampling moment in the position information, and then calculate the first electrical angle according to the first compensation angle and the angle in the position information (see Appendix Fig.15 The angle calculation module is further configured to calculate the second compensation angle based on the angular velocity, the third triggering moment, the third sampling moment, the second triggering moment and the second sampling moment, and then calculate the second electrical angle according to the second compensation angle and the angle (see Appendix Fig.15 The first Clark / Park transformation module is configured to perform coordinate transformation on the three-phase current at the first sampling moment based on the first electrical angle to obtain the first feedback current; the second Clark / Park transformation module is configured to perform coordinate transformation on the three-phase fundamental current at the second sampling moment based on the second electrical angle to obtain the second feedback current.

[0124] The first feedback current includes a first straight-axis feedback current (see Appendix Fig.15 The D-axis feedback current 1) and the first quadrature-axis feedback current (see Appendix Fig.15 The second feedback current includes the second direct-axis feedback current (see Appendix Fig.15 The D-axis feedback current 2) and the second quadrature-axis feedback current (see Appendix Fig.15 The direct-axis current controller is configured to respond to the direct-axis current command (see Appendix Fig.15 The D-axis current command in the D-axis current command) and the first direct-axis feedback current are proportionally processed, and the direct-axis current command and the second direct-axis feedback current are integrated to generate the target direct-axis voltage command (refer to the attached Fig.15 The quadrature axis current controller is configured to respond to the quadrature axis current command (see Appendix Fig.15 The Q-axis current command in the Q axis) and the first quadrature-axis feedback current are proportionally processed, and the quadrature-axis current command and the second quadrature-axis feedback current are integrated to generate a target quadrature-axis voltage command (see Appendix Fig.15 Finally, the motor operation is controlled according to the target direct-axis voltage command and the target quadrature-axis voltage command.

[0125] The detailed processing flow of each module or controller in the embodiment of the present application has been described in detail in the aforementioned embodiment and will not be repeated here.

[0126] In one embodiment of the present application, refer to the attached Fig.15 , also includes: Inverse Park / Clark transformation module (refer to Appendix Figure 7 The inverse Park / Clark transformation in the three-phase stationary coordinate system is configured to convert the target direct-axis voltage command and the target quadrature-axis voltage command into the Alpha-axis voltage command and the Beta-axis voltage command in the three-phase stationary coordinate system, respectively; the PWM modulation module is configured to convert the Alpha-axis voltage command and the Beta-axis voltage command into multiple PWM signals; the output of the inverter can be adjusted through the multiple PWM signals, thereby controlling the operation of the motor.

[0127] In one embodiment of the present application, refer to the attached Fig.15 The first current sampling module and the second current sampling module can also obtain two-phase current, for example, U / V two-phase current, V / W two-phase current, and W / U two-phase current. Moreover, the processing process based on the two-phase current is the same as the above embodiment, and will not be repeated here.

[0128] In one embodiment of the present application, refer to the attached Fig.15, the first current sampling module and the second current sampling module can be a variety of analog-to-digital converters. For example, the first current sampling module and the second current sampling module can both be Σ-Δ analog-to-digital converters, in which case the first current sampling module can sample a low decimation rate for decoding, and the second current sampling module can sample a high decimation rate for decoding (decimation rate less than the first threshold is a low decimation rate, and decimation rate not less than the first threshold is a high decimation rate); for another example, the first current sampling module and the second current sampling module can both be successive approximation analog-to-digital converters, in which case the first current sampling module uses a filter with a low cutoff frequency for data processing, and the second current sampling module uses a filter with a high cutoff frequency for data processing (similarly, a filter with a cutoff frequency less than the second threshold is a filter with a low cutoff frequency, and a filter with a cutoff frequency not less than the second threshold is a filter with a high cutoff frequency). For another example, the first current sampling module is a successive approximation analog-to-digital converter, so that the first sampling moment can be flexibly adjusted to avoid ringing noise of the power device. The second current sampling module is a Σ-Δ analog-to-digital converter, which can improve sampling accuracy.

[0129] The embodiment of the present application also provides a motor control device, including: an acquisition module, used to acquire a current command, a first feedback current and a second feedback current controlled by a current loop; the current command includes a direct-axis current command and a quadrature-axis current command; the first feedback current includes a first direct-axis feedback current and a first quadrature-axis feedback current; the second feedback current includes a second direct-axis feedback current and a second quadrature-axis feedback current; the first feedback current is a sampled current of the three-phase current at a moment before the current loop performs a control operation; the second feedback current is a sampled current of the center point of the PWM carrier; a proportional module, used to perform proportional processing on the direct-axis current command and the first direct-axis feedback current, and to perform integral processing on the direct-axis current command and the second direct-axis feedback current to generate a target direct-axis voltage command; an integral module, used to perform proportional processing on the quadrature-axis current command and the first quadrature-axis feedback current, and to perform integral processing on the quadrature-axis current command and the second quadrature-axis feedback current to generate a target quadrature-axis voltage command; a control module, used to control the operation of the motor based on the target direct-axis voltage command and the target quadrature-axis voltage command.

[0130] The details of the embodiments of the present application have been described in the aforementioned embodiments and will not be repeated here.

[0131] An embodiment of the present application further provides a computer storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps of the motor control method of any of the above embodiments are implemented.

[0132] An embodiment of the present application further provides a motor driver, including a memory and a processor, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the steps of the motor control method of any of the above embodiments are implemented.

[0133] It should be noted that the above embodiments can be freely combined as needed. The above are only preferred embodiments of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A motor control method, characterized in that: include: Acquire a current command, a first feedback current, and a second feedback current of a current loop control; the current command includes a direct-axis current command and a quadrature-axis current command; The first feedback current includes a first direct-axis feedback current and a first quadrature-axis feedback current; the second feedback current includes a second direct-axis feedback current and a second quadrature-axis feedback current; the first feedback current is a sampling current of the three-phase current at a moment before the current loop performs a control operation; the second feedback current is a sampling current of the center point of the PWM carrier; Performing proportional processing on the direct-axis current command and the first direct-axis feedback current, and performing integral processing on the direct-axis current command and the second direct-axis feedback current to generate a target direct-axis voltage command; Performing proportional processing on the quadrature-axis current command and the first quadrature-axis feedback current, and performing integral processing on the quadrature-axis current command and the second quadrature-axis feedback current, so as to generate a target quadrature-axis voltage command; Based on the target direct-axis voltage command and the target quadrature-axis voltage command, the operation of the motor is controlled.

2. The motor control method according to claim 1, characterized in that: The performing proportional processing on the direct-axis current command and the first direct-axis feedback current, and performing integral processing on the direct-axis current command and the second direct-axis feedback current to generate a target direct-axis voltage command specifically includes: Calculating a first direct-axis current error based on the direct-axis current command and the first direct-axis feedback current; Performing proportional processing on the first direct-axis current error to obtain a first direct-axis voltage command; Calculating a second direct-axis current error based on the direct-axis current command and the second direct-axis feedback current; Integrating the second direct-axis current error to obtain a second direct-axis voltage command; A target direct-axis voltage command is generated based on the first direct-axis voltage command and the second direct-axis voltage command.

3. The motor control method according to claim 1, characterized in that: The performing proportional processing on the quadrature-axis current command and the first quadrature-axis feedback current, and performing integral processing on the quadrature-axis current command and the second quadrature-axis feedback current to generate a target quadrature-axis voltage command specifically includes: Calculating a first quadrature-axis current error based on the quadrature-axis current command and the first quadrature-axis feedback current; Performing proportional processing on the first quadrature-axis current error to obtain a first quadrature-axis voltage command; Calculating a second quadrature-axis current error based on the quadrature-axis current command and the second quadrature-axis feedback current; Integrating the second quadrature-axis current error to obtain a second quadrature-axis voltage command; A target quadrature-axis voltage command is generated based on the first quadrature-axis voltage command and the second quadrature-axis voltage command.

4. The motor control method according to claim 1, characterized in that: The sampling steps of the first feedback current and the second feedback current include: Acquire the three-phase current at a first sampling moment based on the first trigger signal, and acquire the three-phase fundamental current at a second sampling moment based on the second trigger signal, wherein the first sampling moment is the moment before the current loop performs a control operation, and the second sampling moment is the moment corresponding to the center point of the PWM carrier; latching the position information of the motor at the third sampling moment based on the third trigger signal; Performing coordinate transformation on the three-phase current based on the position information, the third triggering moment of the third triggering signal, the third sampling moment, the first triggering moment of the first triggering signal and the first sampling moment to obtain a first feedback current; The coordinate transformation of the three-phase fundamental current is performed based on the position information, the third triggering time, the third sampling time, the second triggering time of the second trigger signal and the second sampling time to obtain a second feedback current.

5. The motor control method according to claim 4, characterized in that: The position information includes an angle and an angular velocity; the coordinate transformation of the three-phase current based on the position information, the third triggering moment of the third trigger signal, the third sampling moment, the first triggering moment of the first trigger signal and the first sampling moment to obtain the first feedback current specifically includes: Calculating a first compensation angle based on the angular velocity, the third triggering moment, the third sampling moment, the first triggering moment, and the first sampling moment; Calculating a first electrical angle based on the first compensation angle and the angle; The three-phase current is subjected to coordinate transformation based on the first electrical angle to obtain a first feedback current.

6. The motor control method according to claim 4, characterized in that: The position information includes an angle and an angular velocity; the coordinate transformation of the three-phase fundamental current based on the position information, the third trigger moment, the third sampling moment, the second trigger moment of the second trigger signal and the second sampling moment to obtain the second feedback current specifically includes: Calculating a second compensation angle based on the angular velocity, the third triggering moment, the third sampling moment, the second triggering moment, and the second sampling moment; calculating a second electrical angle based on the second compensation angle and the angle; The coordinate transformation is performed on the three-phase fundamental current based on the second electrical angle to obtain the second feedback current.

7. The motor control method according to claim 1, characterized in that: Also includes: When the sampling moment corresponding to the three-phase current is after the preset switching tube moment, and the time interval between the sampling moment corresponding to the three-phase current and the switching tube moment is less than the time threshold, the sampling moment corresponding to the three-phase current is moved forward.

8. A motor control device, characterized in that: The device comprises: An acquisition module, used for acquiring a current command, a first feedback current, and a second feedback current of a current loop control; the current command includes a direct-axis current command and a quadrature-axis current command; the first feedback current includes a first direct-axis feedback current and a first quadrature-axis feedback current; the second feedback current includes a second direct-axis feedback current and a second quadrature-axis feedback current; the first feedback current is a sampling current of a three-phase current at a moment before the current loop performs a control operation; the second feedback current is a sampling current of a center point of a PWM carrier; a proportional module, configured to perform proportional processing on the direct-axis current command and the first direct-axis feedback current, and perform integral processing on the direct-axis current command and the second direct-axis feedback current, so as to generate a target direct-axis voltage command; an integration module, configured to perform proportional processing on the quadrature-axis current command and the first quadrature-axis feedback current, and perform integration processing on the quadrature-axis current command and the second quadrature-axis feedback current, so as to generate a target quadrature-axis voltage command; The control module is used to control the operation of the motor based on the target direct-axis voltage command and the target quadrature-axis voltage command.

9. A computer storage medium, characterized in that A computer program is stored thereon, and when the computer program is executed by a processor, the steps of the motor control method described in any one of claims 1 to 7 are implemented.

10. A motor driver, characterized in that: The method comprises a memory and a processor, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the steps of the motor control method according to any one of claims 1 to 7 are implemented.

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