Motor current modulation method, device, apparatus and storage medium

Abstract

The application discloses a motor current modulation method and device, equipment and storage medium, and relates to the technical field of motors. The technical scheme provided by the application comprises: acquiring a current value of a torque current of a motor rotor; determining a current value of a stator current of the motor according to the current value of the torque current; wherein the stator current is composed of the torque current of the motor rotor and an excitation current; determining a current value of the excitation current according to the current value of the stator current and the current value of the torque current; and modulating the excitation current according to the current value of the excitation current. Through the above technical means, the excitation current of the motor is actively modulated to increase the effective signal of the three-phase current, avoid the noise from covering the effective signal of the three-phase current, improve the detection accuracy of the software observer, and further improve the control efficiency of the motor, so as to solve the problems of low detection accuracy of the software observer and low control efficiency of the motor when the motor is in light load or low-speed operation in the prior art.

Description

Technical Field

[0001] This application relates to the field of motor technology, and in particular to a method, apparatus, device and storage medium for motor current modulation. Background Technology

[0002] Field-oriented control (FOC) is a common technique for motor drive control. FOC technology allows for precise control of the motor based on the electrical angle and speed of the rotor detected by a software observer. Software observers include flux linkage observers and back EMF observers.

[0003] In existing technologies, the error between the actual and estimated flux linkage is compensated for in the stator flux linkage calculation through inverter nonlinearity compensation. After inverter nonlinearity compensation, the flux linkage observer detects the electrical angle and speed of the motor rotor by collecting the three-phase current of the motor. However, when the motor is under light load or at low speed, if the amplitude of the stator current is small, noise will occupy the main part of the three-phase current. Even if the stator flux linkage is compensated, the flux linkage observer cannot accurately estimate the electrical angle and speed of the rotor based on the three-phase current. Therefore, the detection accuracy of the software observer is low when the motor is under light load or at low speed, which is not conducive to effective motor control and thus affects the motor control efficiency. Summary of the Invention

[0004] This application provides a motor current modulation method, apparatus, device, and storage medium. By actively modulating the excitation current of the motor to increase the effective signal of the three-phase current, it avoids noise from covering the effective signal of the three-phase current, improves the detection accuracy of the software observer, and thus improves the control efficiency of the motor. This solves the problems of low detection accuracy of the software observer and low motor control efficiency when the motor is under light load or at low speed in the prior art.

[0005] In a first aspect, this application provides a method for modulating motor current, including:

[0006] Obtain the torque current value of the motor rotor;

[0007] The stator current of the motor is determined based on the torque current value; wherein the stator current is synthesized from the rotor torque current and the excitation current of the motor.

[0008] The excitation current value is determined based on the stator current value and the torque current value.

[0009] The excitation current is modulated according to the current value of the excitation current.

[0010] Secondly, this application provides a motor current modulation device, comprising:

[0011] The torque current acquisition module is configured to acquire the current value of the torque current of the motor rotor;

[0012] The stator current determination module is configured to determine the stator current value of the motor stator based on the current value of the torque current; wherein the stator current is synthesized from the torque current and the excitation current of the motor rotor;

[0013] The excitation current determination module is configured to determine the excitation current value based on the current value of the stator current and the current value of the torque current.

[0014] The excitation current modulation module is configured to modulate the excitation current according to the current value of the excitation current.

[0015] Thirdly, this application provides a motor current modulation device, comprising:

[0016] One or more processors; a storage device storing one or more programs that, when executed by the one or more processors, cause the one or more processors to implement the motor current modulation method as described in the first aspect.

[0017] Fourthly, this application provides a storage medium containing computer-executable instructions, which, when executed by a computer processor, are used to perform the motor current modulation method as described in the first aspect.

[0018] This application collects the torque current value in each control cycle and estimates the stator current value based on the torque current value. Since the stator current is synthesized from the torque current and the excitation current, the excitation current value can be calculated based on the electronic current value and the torque current value, and the excitation current can be modulated based on the excitation current value. Through the above technical means, since the excitation current affects the magnetic field strength of the motor rotor but not the torque of the motor rotor, that is, the change in the excitation current does not affect the speed of the motor rotor. Therefore, when the excitation current increases, the effective signal of the three-phase current is enhanced, but the motor speed can be maintained at a low speed. This allows the software observer to capture the effective signal of the three-phase current and detect the accurate angle and speed. Then, the controller can perform precise control of the motor based on the accurate angle and speed, improving the motor control performance when the motor is running under light load or at low speed, and ensuring that the motor can start normally. Attached Figure Description

[0019] Figure 1 This is a flowchart of a motor current modulation method provided in an embodiment of this application;

[0020] Figure 2This is a schematic block diagram of the dual-loop control system of speed loop and current loop provided in the embodiments of this application;

[0021] Figure 3 This is a flowchart illustrating the determination of stator current values ​​provided in an embodiment of this application;

[0022] Figure 4 This is a flowchart illustrating the accumulated stator current values ​​provided in an embodiment of this application;

[0023] Figure 5 This is a flowchart of the cumulative stator current value provided in the embodiments of this application;

[0024] Figure 6 This is a schematic diagram of the dual-loop control system for automatic adjustment of excitation current provided in the embodiments of this application;

[0025] Figure 7 This is a schematic diagram of the structure of a motor current modulation device provided in an embodiment of this application;

[0026] Figure 8 This is a schematic diagram of the structure of a motor current modulation device provided in an embodiment of this application. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this application clearer, specific embodiments of this application will be described in further detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely for explaining this application and not for limiting it. It should also be noted that, for ease of description, only the parts relevant to this application are shown in the drawings, not all of them. Before discussing exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although the flowcharts describe operations (or steps) as sequential processes, many of these operations can be performed in parallel, concurrently, or simultaneously. Furthermore, the order of the operations can be rearranged. A process can be terminated when its operation is completed, but it may also have additional steps not included in the drawings. A process can correspond to a method, function, procedure, subroutine, subroutine, etc.

[0028] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0029] The motor current modulation method provided in this embodiment can be executed by a motor current modulation device, which can be implemented by software and / or hardware. The motor current modulation device can consist of two or more physical entities, or it can consist of a single physical entity. For example, the motor current modulation device can be a motor controller or a device equipped with a motor, such as an agricultural machine like a plant protection machine.

[0030] The motor current modulation device is equipped with at least one type of operating system. Based on this operating system, the device can install at least one application. This application can be a built-in application of the operating system or an application downloaded from a third-party device or server. In this embodiment, the motor current modulation device has at least one application capable of executing the motor current modulation method; therefore, the motor current modulation device itself can also be the application itself.

[0031] For ease of understanding, this embodiment uses a motor controller as the main body for executing the motor current modulation method as an example for description.

[0032] In one embodiment, to save costs, the brushless DC motor of the agricultural drone abandons Hall sensors and uses a flux linkage observer to detect the electrical angle and electrical speed of the motor rotor. The motor controller of the agricultural drone can perform FOC control on the motor based on the electrical angle and electrical speed collected by the flux linkage observer to control the motor rotor to a preset electrical angle and electrical speed. The drive circuit of the brushless DC motor is implemented using a three-phase inverter circuit. Since the nonlinearity of the three-phase inverter circuit will affect the detection accuracy of the flux linkage observer, the error between the actual flux linkage and the estimated flux linkage can be compensated for in the stator flux linkage calculation through nonlinearity compensation of the three-phase inverter circuit. After nonlinearity compensation of the three-phase inverter circuit, the flux linkage observer detects the electrical angle and electrical speed of the motor rotor by collecting the three-phase current of the motor. However, when the motor is running under light load or at low speed, if the amplitude of the stator current of the motor is small, noise will occupy the main part of the three-phase current. Even if the stator flux linkage is compensated, it is difficult to collect an effective signal of the three-phase current, so that the flux linkage observer cannot accurately estimate the electrical angle and electrical speed of the rotor based on the three-phase current. Therefore, the detection accuracy of the software observer is low when the motor is under light load or running at low speed, which is not conducive to the effective control of the motor. The motor cannot rotate effectively, such as by shaking, resulting in poor motor control effect and low control efficiency.

[0033] To address the issues of low detection accuracy of software observers and low motor control efficiency when the motor is under light load or at low speed in the prior art, this embodiment provides a motor current modulation method.

[0034] Figure 1 A flowchart of a motor current modulation method provided in an embodiment of this application is given. (Reference) Figure 1 The motor current modulation method specifically includes:

[0035] S110: Obtain the torque current value of the motor rotor.

[0036] Torque current refers to the current in the tangential direction of the motor rotor's rotation, while excitation current refers to the current in the radial direction of the motor rotor's rotation. For example, FOC control primarily uses three PID (Proportional Integral Differential) control loops: the current loop, speed loop, and position loop, from inner to outer. This means that the motor torque is controlled through current feedback, then the motor rotor speed is controlled through the motor torque, and finally, the rotor angle is controlled through the motor rotor speed. Assuming the motor operates at low speed in this embodiment, a dual-loop control algorithm based on the speed and current loops can be used to control the motor's low-speed operation. Figure 2 This is a schematic block diagram of the dual-loop control system (speed loop and current loop) provided in an embodiment of this application. Figure 2As shown, to maintain the rotor speed at the setpoint, the controller calculates the deviation between the setpoint speed and the motor speed ω fed back by the flux linkage observer in each control cycle. Based on this deviation, it uses a PI control algorithm to calculate the torque current setpoint for the current control cycle. The flux linkage observer then calculates the torque current setpoint based on the motor's three-phase current I... a I b and I c The current rotor speed ω and rotor angle θ of the motor are detected, and the three-phase current I is converted using Clark transformation. a I b and I c Converted to α-axis current I in α-β coordinate system α and β-axis current I β Based on the α-axis current I through Park transformation α β-axis current I β The rotor speed ω and rotor angle θ determine the torque current I. q and excitation current I d Calculate the torque current setpoint and the current motor torque current I. q The deviation is calculated, and the torque voltage V is calculated based on this deviation using a PI control algorithm. q Calculate the excitation voltage setpoint and the current motor excitation current I. d The deviation is calculated, and the excitation voltage V is calculated based on this deviation using a PI control algorithm. d The inverse Park transform, also known as the RevPark transform, is based on the torque-voltage V. q Excitation voltage V d The α-axis voltage V in the α-β coordinate system is determined by the rotor angle θ. α and β-axis voltage V β The SVPWM (Space Vector Pulse Width Modulation) algorithm is used based on the α-axis voltage V. α and β-axis voltage V β Calculate the current three-phase voltage V of the motor. a V b and V c The input value is used to adjust the three-phase voltage of the motor to the corresponding input value, so as to control the speed of the motor to the speed setpoint, thus completing one control cycle.

[0037] In this embodiment, the torque current setpoint is obtained as the torque current value. The torque current setpoint can reflect the rotor speed of the motor to a certain extent. Based on the torque current setpoint, it can be determined whether the motor is in a light load or low-speed operating state. When the motor is in a light load or low-speed operating state, the excitation current is actively modulated; when the motor is in a medium-to-high speed operating state, the active modulation of the excitation current is discontinued. It should be noted that the active modulation process of the excitation current is independent of the nonlinear compensation of the three-phase inverter circuit; that is, regardless of whether active modulation of the excitation current is performed, the nonlinear compensation of the three-phase inverter circuit will still be performed.

[0038] S120. Determine the stator current value of the motor based on the torque current value; wherein the stator current is synthesized from the rotor torque current and the excitation current of the motor.

[0039] For example, torque current and excitation current can be combined to form stator current. Increasing the amplitude of the stator current can enhance the effective signal of the three-phase current. The magnitude of the torque current affects the rotor speed, while the magnitude of the excitation current affects the rotor's magnetic field strength without affecting the rotor speed. Therefore, this embodiment proposes to increase the amplitude of the stator current and thus enhance the effective signal of the three-phase current by modulating the value of the excitation current.

[0040] The torque current setpoint is determined by the deviation between the speed setpoint and the rotor speed ω fed back by the flux linkage observer. When the speed setpoint or the rotor speed ω changes, the torque current setpoint will also change accordingly. Consequently, the stator current value will also change. To ensure the motor's dynamic response, the stator current value is dynamically determined in each control cycle. For example, Figure 3 This is a flowchart illustrating the determination of the stator current value according to an embodiment of this application. For example... Figure 3 As shown, the steps for determining the minimum stator current value specifically include S1201-S1202:

[0041] S1201. High-pass filtering is performed on the torque current value to obtain the high-frequency component of the torque current.

[0042] For example, the torque current setpoint is input to a high-pass filter with a cutoff frequency of 1 Hz to obtain the high-frequency component of the high-pass filter output. The high-frequency component can characterize the jitter amplitude of the torque current. The larger the high-frequency component, the larger the jitter amplitude of the torque current, which indicates a higher rotor speed. The smaller the high-frequency component, the smaller the amplitude jitter amplitude of the torque current, which indicates a lower rotor speed.

[0043] S1202. Compare the high-frequency component with the preset reference threshold, and determine the stator current value based on the comparison result.

[0044] The preset reference threshold is the amplitude of torque current fluctuation when the motor fails to rotate and vibrates in place, as set in this embodiment. The high-frequency component is compared with the preset reference threshold. If the high-frequency component is greater than the preset reference threshold, it indicates that the motor is rotating; if the high-frequency component is less than or equal to the preset reference threshold, it indicates that the motor is vibrating in place. Generally, the preset reference threshold can be set to 0.1.

[0045] In this embodiment, when the high-frequency component is greater than a preset reference threshold, the sum of the first current value and the preset current value is used as the stator current value; when the high-frequency component is less than or equal to the preset reference threshold, the difference between the first current value and the preset current value is used as the stator current value; wherein, the first current value is the stator current value of the previous control cycle. For example, assume the first current value corresponding to the initial control cycle is zero, and the preset current value is 0.01. When it is determined that the motor is rotating, the stator current value of the previous control cycle is increased by 0.01 to obtain the stator current value of the current control cycle. When it is determined that the motor is in a stationary state, the stator current value of the previous control cycle is decreased by 0.01 to obtain the stator current value of the current control cycle. In this embodiment, when the motor is rotating, the stator current value is increased to ensure that the flux linkage observer can capture the effective signal of the three-phase current; when the motor is in a stationary state, the stator current value is decreased to save energy consumption.

[0046] However, a larger stator current is not always better. With a constant torque current, a larger stator current indicates a larger excitation current, which is a reactive power loss in the motor, resulting in additional energy loss. To conserve this reactive power, the stator current can be accumulated to its maximum value, sufficient to capture a valid three-phase current signal when the motor is under light load or low speed operation. Accumulation can then cease, ensuring that a valid three-phase current signal can be captured even at this current value. For example... Figure 4 This is a flowchart illustrating the accumulated stator current values ​​provided in an embodiment of this application. For example... Figure 4 As shown, the steps for accumulating the stator current value specifically include S12021-S12023:

[0047] S12021. Compare the first current value with the preset maximum current value.

[0048] S12022. When the first current value is equal to the preset maximum current value, the preset maximum current value is assigned to the current value of the stator current.

[0049] S12023. If the first current value is less than the preset maximum current value, the sum of the first current value and the preset current value shall be used as the current value of the stator current.

[0050] The preset maximum current value can be understood as the maximum stator current value when the motor is under light load or low speed operation and a valid three-phase current signal can be obtained. When the stator current value reaches the preset maximum current value, the flux linkage observer can obtain a valid three-phase current signal. Therefore, the preset maximum current value can be assigned to the stator current value of the current control cycle to avoid blindly increasing the stator current and thus increasing reactive power loss.

[0051] Similarly, the stator current value should not be reduced blindly. Figure 5 This is a flowchart illustrating the cumulative stator current values ​​provided in an embodiment of this application. For example... Figure 5 As shown, the steps for cumulatively reducing the stator current value specifically include S12024-S12026:

[0052] S12024. Compare the first current value with the preset minimum current value.

[0053] S12025. When the first current value is equal to the preset minimum current value, the preset minimum current value is assigned to the current value of the stator current.

[0054] S12026. If the first current value is greater than the preset maximum current value, the difference between the first current value and the preset current value shall be used as the stator current value.

[0055] For example, since the stator current cannot be negative, the preset minimum current value can generally be set to 0. When the stator current decreases to zero, the stator current value will no longer decrease.

[0056] S130. Determine the excitation current value based on the stator current value and the torque current value.

[0057] Since the stator current is synthesized from the torque current and the excitation current, the excitation current value of the current control cycle can be calculated based on the stator current value and the torque current value of the current control cycle.

[0058] In one embodiment, the torque current value is compared with the stator current value, and the excitation current value is determined based on the comparison result. For example, if the stator current value is greater than the torque current value, it indicates that when controlling the motor based on the current torque current setpoint, the flux linkage observer still has difficulty capturing the effective signal of the three-phase current. Therefore, the effective signal of the three-phase current is increased by increasing the excitation current value. If the stator current value is less than or equal to the torque current value, it indicates that when controlling the motor based on the current torque current setpoint, the flux linkage observer can capture the effective signal of the three-phase current, and therefore, it is not necessary to increase the effective signal of the three-phase current by increasing the excitation current value.

[0059] In this embodiment, when the torque current is greater than or equal to the stator current, the excitation current is determined to be zero; when the torque current is less than the stator current, the excitation current is determined based on a first preset formula, which is:

[0060]

[0061] Among them, I dref I is the value of the excitation current. min I is the stator current value. qref Let be the value of the torque current. It can be understood that the value of the stator current at the same moment is equal to the square root of the sum of the squares of the excitation current and the torque current. Therefore, the first preset formula can be determined based on the synthesis relationship between the stator current, the excitation current, and the torque current.

[0062] S140. Modulate the excitation current according to the current value of the excitation current.

[0063] For example, the excitation current setpoint of the current control cycle is modulated to the current value of the currently determined excitation current. Figure 6 This is a schematic block diagram of the dual-loop control system for automatic adjustment of excitation current provided in an embodiment of this application. Figure 6 As shown, the active modulator of the excitation current outputs the excitation current setpoint based on the torque current setpoint, and uses the excitation current setpoint and the torque current setpoint as the input of the current loop.

[0064] In summary, the motor current modulation method provided in this application collects the torque current value in each control cycle and estimates the stator current value based on the torque current value. Since the stator current is synthesized from the torque current and the excitation current, the excitation current value can be calculated based on the electronic current value and the torque current value, and the excitation current is modulated based on the excitation current value. Through the above technical means, since the excitation current affects the magnetic field strength of the motor rotor but not the torque of the motor rotor, that is, the change in the excitation current does not affect the speed of the motor rotor. Therefore, when the excitation current increases, the effective signal of the three-phase current is enhanced, but the motor speed can be maintained at a low speed. This allows the software observer to capture the effective signal of the three-phase current and detect the accurate angle and speed. Then, the controller can perform precise control of the motor based on the accurate angle and speed, improving the motor control performance when the motor is running under light load or at low speed, and ensuring that the motor can start normally.

[0065] Based on the above embodiments, Figure 7 This is a schematic diagram of a motor current modulation device provided in an embodiment of this application. (Reference) Figure 7 The motor current modulation device provided in this embodiment specifically includes: a torque current acquisition module 21, a stator current determination module 22, an excitation current determination module 23, and an excitation current modulation module 24.

[0066] Among them, the torque current acquisition module is configured to acquire the current value of the torque current of the motor rotor;

[0067] The stator current determination module is configured to determine the stator current value of the motor stator based on the torque current value; wherein the stator current is synthesized from the torque current and excitation current of the motor rotor.

[0068] The excitation current determination module is configured to determine the excitation current value based on the stator current value and the torque current value.

[0069] The excitation current modulation module is configured to modulate the excitation current according to the current value of the excitation current.

[0070] Based on the above embodiments, the stator current acquisition includes: a high-pass filtering submodule, configured to perform high-pass filtering on the current value of the torque current to obtain the high-frequency component of the torque current; and a stator current determination submodule, configured to compare the high-frequency component with a preset reference threshold and determine the current value of the stator current based on the comparison result.

[0071] Based on the above embodiments, the stator current determination submodule includes: a current accumulation unit configured to, when the high-frequency component is greater than a preset reference threshold, take the sum of a first current value and a preset current value as the stator current value; wherein the first current value is the stator current value of the previous control cycle; and a current deduction unit configured to, when the high-frequency component is less than or equal to the preset reference threshold, take the difference between the first current value and the preset current value as the stator current value.

[0072] Based on the above embodiments, the current accumulation unit further includes: a first comparison subunit, configured to compare the first current value with a preset maximum current value before using the sum of the first current value and a preset current value as the current value of the stator current; and a first assignment subunit, configured to assign the preset maximum current value to the current value of the stator current when the first current value is equal to the preset maximum current value.

[0073] Based on the above embodiments, the current accumulation unit further includes: a second comparison subunit configured to compare the first current value with a preset minimum current value before using the difference between the first current value and the preset current value as the current value of the stator current; and a second assignment subunit configured to assign the preset minimum current value to the current value of the stator current when the first current value is equal to the preset minimum current value.

[0074] Based on the above embodiments, the excitation current determination module includes: an excitation current determination submodule, configured to compare the current value of the torque current with the current value of the stator current, and determine the current value of the excitation current based on the comparison result.

[0075] Based on the above embodiments, the excitation current determination submodule includes: a first determination unit configured to determine that the excitation current value is zero when the torque current value is greater than or equal to the stator current value; and a second determination unit configured to determine the excitation current value based on a first preset formula when the torque current value is less than the stator current value. The first preset formula is:

[0076]

[0077] Among them, I dref I is the current value of the excitation current. min I is the stator current value. qref This is the value of the torque current.

[0078] The motor current modulation device provided in this application, as described above, collects the torque current value in each control cycle and estimates the stator current value based on the torque current value. Since the stator current is synthesized from the torque current and the excitation current, the excitation current value can be calculated based on the electronic current value and the torque current value, and the excitation current is modulated based on the excitation current value. Through the above technical means, since the excitation current affects the magnetic field strength of the motor rotor but not the torque of the motor rotor, that is, the change in the excitation current does not affect the speed of the motor rotor. Therefore, when the excitation current increases, the effective signal of the three-phase current is enhanced, but the motor speed can be maintained in a low-speed operating state. This allows the software observer to capture the effective signal of the three-phase current and detect the accurate angle and speed. Then, the controller can perform precise control of the motor based on the accurate angle and speed, improving the motor control performance when the motor is running under light load or at low speed, and ensuring that the motor can start normally.

[0079] The motor current modulation device provided in this application embodiment can be used to execute the motor current modulation method provided in the above embodiment, and has corresponding functions and beneficial effects.

[0080] Figure 8 This is a schematic diagram of the structure of a motor current modulation device provided in an embodiment of this application, with reference to... Figure 8 The motor current modulation device includes a processor 31, a memory 32, a communication device 33, an input device 34, and an output device 35. The number of processors 31 and the number of memories 32 in the motor current modulation device can be one or more. The processor 31, memory 32, communication device 33, input device 34, and output device 35 of the motor current modulation device can be connected via a bus or other means.

[0081] The memory 32, as a computer-readable storage medium, can be used to store software programs, computer-executable programs, and modules, such as program instructions / modules corresponding to the motor current modulation method in any embodiment of this application (e.g., torque current acquisition module 21, stator current determination module 22, excitation current determination module 23, and excitation current modulation module 24 in the motor current modulation device). The memory 32 may primarily include a program storage area and a data storage area. The program storage area may store the operating system and at least one application program required for a function; the data storage area may store data created based on the use of the device, etc. Furthermore, the memory 32 may include high-speed random access memory and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other non-volatile solid-state storage device. In some instances, the memory may further include memory remotely located relative to the processor, and these remote memories can be connected to the device via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0082] The communication device 33 is used for data transmission.

[0083] The processor 31 executes various functional applications and data processing of the device by running software programs, instructions and modules stored in the memory 32, thereby realizing the above-mentioned motor current modulation method.

[0084] Input device 34 can be used to receive input digital or character information, and to generate key signal inputs related to user settings and function control of the device. Output device 35 may include display devices such as a display screen.

[0085] The motor current modulation device provided above can be used to execute the motor current modulation method provided in the above embodiments, and has corresponding functions and beneficial effects.

[0086] This application embodiment also provides a storage medium containing computer-executable instructions. When executed by a computer processor, the computer-executable instructions are used to perform a motor current modulation method. The motor current modulation method includes: acquiring the current value of the torque current of the motor rotor; determining the current value of the stator current of the motor based on the current value of the torque current; wherein the stator current is synthesized from the torque current of the motor rotor and the excitation current; determining the current value of the excitation current based on the current value of the stator current and the current value of the torque current; and modulating the excitation current based on the current value of the excitation current.

[0087] Storage medium – any type of memory device or storage device. The term “storage medium” is intended to include: mounting media, such as CD-ROM, floppy disk, or magnetic tape devices; computer system memory or random access memory, such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; non-volatile memory, such as flash memory, magnetic media (e.g., hard disk or optical storage); registers or other similar types of memory elements, etc. Storage medium may also include other types of memory or combinations thereof. Furthermore, storage medium may reside in a first computer system in which the program is executed, or it may reside in a different second computer system connected to the first computer system via a network (such as the Internet). The second computer system can provide program instructions to the first computer for execution. The term “storage medium” can include two or more storage media residing in different locations (e.g., in different computer systems connected via a network). Storage medium may store program instructions (e.g., specifically implemented as a computer program) executable by one or more processors.

[0088] Of course, the computer-executable instructions provided in the embodiments of this application are not limited to the motor current modulation method described above, but can also execute related operations in the motor current modulation method provided in any embodiment of this application.

[0089] The motor current modulation device, storage medium, and motor current modulation equipment provided in the above embodiments can execute the motor current modulation method provided in any embodiment of this application. For technical details not described in detail in the above embodiments, please refer to the motor current modulation method provided in any embodiment of this application.

[0090] The above description is merely a preferred embodiment and the technical principles employed in this application. This application is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions that can be made by those skilled in the art will not depart from the scope of protection of this application. Therefore, although this application has been described in detail through the above embodiments, this application is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of this application. The scope of this application is determined by the scope of the claims.

Claims

1. A method for modulating motor current, characterized in that, include: Obtain the current value of the torque current of the motor stator; The torque current value is high-pass filtered to obtain the high-frequency component of the torque current; The high-frequency component is compared with a preset reference threshold, and the stator current value is determined based on the comparison result; wherein, the stator current is synthesized from the torque current and excitation current of the motor stator; The excitation current value is determined based on the stator current value and the torque current value. The excitation current is modulated according to the current value of the excitation current.

2. The motor current modulation method according to claim 1, characterized in that, The step of comparing the high-frequency component with a preset reference threshold and determining the stator current value based on the comparison result includes: When the high-frequency component is greater than a preset reference threshold, the sum of the first current value and the preset current value is taken as the current value of the stator current; wherein, the first current value is the current value of the stator current in the previous control cycle. When the high-frequency component is less than or equal to a preset reference threshold, the difference between the first current value and the preset current value is taken as the current value of the stator current.

3. The motor current modulation method according to claim 2, characterized in that, Before using the sum of the first current value and the preset current value as the stator current value, the method further includes: Compare the first current value with the preset maximum current value; When the first current value is equal to the preset maximum current value, the preset maximum current value is assigned to the current value of the stator current.

4. The motor current modulation method according to claim 2, characterized in that, Before using the difference between the first current value and the preset current value as the stator current value, the method further includes: Compare the first current value with the preset minimum current value; If the first current value is equal to the preset minimum current value, the preset minimum current value is assigned to the current value of the stator current.

5. The motor current modulation method according to claim 1, characterized in that, Determining the excitation current value based on the stator current value and the torque current value includes: The current value of the torque current is compared with the current value of the stator current, and the current value of the excitation current is determined based on the comparison result.

6. The motor current modulation method according to claim 5, characterized in that, Determining the current value of the excitation current based on the comparison result includes: If the value of the torque current is greater than or equal to the value of the stator current, the value of the excitation current is determined to be zero. When the torque current is less than the stator current, the excitation current is determined based on a first preset formula, which is: in, The value of the excitation current. The current value of the stator current. The value of the torque current.

7. A motor current modulation device, characterized in that, include: The torque current acquisition module is configured to acquire the current value of the torque current of the motor stator; The stator current determination module is configured to perform high-pass filtering on the current value of the torque current to obtain the high-frequency component of the torque current; compare the high-frequency component with a preset reference threshold, and determine the current value of the stator current based on the comparison result; wherein the stator current is synthesized from the torque current and excitation current of the motor stator; The excitation current determination module is configured to determine the excitation current value based on the current value of the stator current and the current value of the torque current. The excitation current modulation module is configured to modulate the excitation current according to the current value of the excitation current.

8. A motor current modulation device, characterized in that, include: One or more processors; A storage device for storing one or more programs that, when executed by one or more processors, cause the one or more processors to implement the motor current modulation method as described in any one of claims 1-6.

9. A storage medium containing computer-executable instructions, characterized in that, The computer-executable instructions, when executed by a computer processor, are used to perform the motor current modulation method as described in any one of claims 1-6.

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