Motor current control method and device
By obtaining the motor speed and obtaining the current control parameters, performing peak current sampling and filtering, the problem of poor current control stability is solved, low-cost and effective motor current control is achieved, and the smooth operation of the motor driving equipment is ensured.
Patent Information
- Application Number
- CN202510471093.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-15
- Publication Date
- 2025-07-25
AI Technical Summary
The six-step square wave control method causes discontinuous current waveform, resulting in poor current control stability, and even damage to the control device.
By acquiring the motor speed, obtaining the current control parameters, including the cutoff frequency, performing peak current sampling and filtering, and generating a smooth current signal.
It realizes low-cost and effective motor current control, ensures smooth operation of the motor drive equipment, and blocks noise in the current signal.
Smart Images
Figure CN120377713A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the field of motor control, and in particular, to a method and device for controlling motor current. Background Art
[0002] The core of controlling a motor drive system is to control the motor current, and by adjusting the motor current, parameters such as the torque, speed, and position of the motor can be controlled.
[0003] The six-step square wave control method is a means of controlling a direct brushless motor. Due to its advantages such as low implementation cost and simple control, the six-step square wave control method has been widely used.
[0004] The six-step control method will cause the current waveform to be discontinuous, which will further lead to poor current control stability and even damage the performance of devices such as the controller. Summary of the Invention
[0005] To overcome the problems existing in the related art, the present disclosure provides a method and device for controlling motor current. The current control parameters are obtained based on the motor speed, and the current signal output by the motor is further processed according to the current control parameters, solving the problem of poor current control effect. While maintaining low implementation cost and simple control, the defects of the six-step square wave control method are effectively compensated, the effective control of the motor current is realized, and the smooth operation of motor drive devices such as electric vehicles is ensured.
[0006] According to the first aspect of the embodiments of the present disclosure, a method for controlling motor current is provided, including: Obtaining current control parameters according to the motor speed; Processing the current signal output by the motor according to the current control parameters.
[0007] Further, the step of obtaining current control parameters according to the motor speed includes: Obtaining the motor speed; Obtaining the current control parameters corresponding to the motor speed according to preset signal processing conditions, where the current control parameters at least include the cut-off frequency corresponding to the motor speed.
[0008] Further, the step of obtaining the motor speed includes: Obtaining the current motor speed; or, Obtaining the motor speed when meeting the preset obtaining conditions.
[0009] Further, the step of processing the current signal output by the motor according to the current control parameters includes: Performing peak current sampling on the current output by the motor to obtain a first current signal; Filter the first current signal according to the cut-off frequency to obtain a filtered second current signal.
[0010] Furthermore, the method further includes: Generate the signal processing condition according to the filtered signal quality obtained at different cut-off frequency values according to the motor speed, and the signal processing condition includes a plurality of corresponding relationships between the motor speed and the cut-off frequency.
[0011] According to a second aspect of an embodiment of the present disclosure, there is provided a motor current control device, including: A parameter configuration module, configured to obtain current control parameters according to the motor speed; A current control module, configured to process the current signal output by the motor according to the current control parameters.
[0012] Furthermore, the parameter configuration module includes: A speed acquisition sub-module, configured to acquire the motor speed; A parameter acquisition sub-module, configured to obtain the current control parameters corresponding to the motor speed according to a preset signal processing condition, and the current control parameters at least include the cut-off frequency corresponding to the motor speed.
[0013] Furthermore, the speed acquisition sub-module includes: A first speed acquisition sub-module, configured to acquire the current motor speed; A second speed acquisition sub-module, configured to acquire the motor speed when meeting a preset acquisition condition.
[0014] Furthermore, the current control module includes: A current sampling sub-module, configured to perform peak current sampling on the current output by the motor to obtain a first current signal; A first filtering sub-module, configured to filter the first current signal according to the cut-off frequency to obtain a filtered second current signal.
[0015] According to a third aspect of an embodiment of the present disclosure, there is provided a computer device, including: A processor; A memory for storing instructions executable by the processor; Wherein, the processor is configured to: Obtain current control parameters according to the motor speed; Process the current signal output by the motor according to the current control parameters.
[0016] The technical solutions provided by the embodiments of the present disclosure may include the following beneficial effects: obtaining a current control parameter according to the motor speed, and then processing the current signal output by the motor based on the current control parameter. On the premise of analyzing the correlation between the motor speed and the current, a solution for selecting a current signal processing strategy based on the motor speed is proposed, which solves the problem of poor current control stability and realizes low-cost and effective control of the motor current signal.
[0017] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The accompanying drawings herein are incorporated into the specification and constitute a part of this specification, showing embodiments consistent with the present disclosure, and are used together with the specification to explain the principles of the present disclosure.
[0019] Figure 1 is a flowchart of a method for controlling a motor current shown according to an exemplary embodiment.
[0020] Figure 2 is a flowchart of processing a current signal in another method for controlling a motor current shown according to an exemplary embodiment.
[0021] Figure 3 is a schematic diagram of a current signal waveform shown according to an exemplary embodiment.
[0022] Figure 4 is a flowchart of another method for controlling a motor current shown according to an exemplary embodiment.
[0023] Figure 5 is a schematic diagram of the relationship between the speed and the cut-off frequency shown according to an exemplary embodiment.
[0024] Figure 6 is a flowchart of another method for controlling a motor current shown according to an exemplary embodiment.
[0025] Figure 7 is a block diagram of a device for controlling a motor current shown according to an exemplary embodiment.
[0026] Figure 8 is a schematic diagram of the structure of a parameter configuration module 701 shown according to an exemplary embodiment.
[0027] Figure 9 is a schematic diagram of the structure of a speed acquisition sub-module 801 shown according to an exemplary embodiment.
[0028] Figure 10 is a schematic diagram of the structure of a current control module 702 shown according to an exemplary embodiment. Detailed implementation manners
[0029] Here, exemplary embodiments will be described in detail, and examples thereof are shown in the drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation manners described in the following exemplary embodiments do not represent all implementation manners consistent with the present disclosure. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.
[0030] The six-step square wave control method is a means for controlling a direct brushless motor. Due to its advantages such as low implementation cost and simple control, the six-step square wave control method has been widely used.
[0031] The six-step method control mode will cause the current waveform to be discontinuous, which will further lead to poor current control stability and even damage the performance of devices such as the controller.
[0032] To solve the above problems, embodiments of the present disclosure provide a method and device for controlling motor current. By obtaining a strategy for processing the current signal based on the motor speed, the problem of poor current control stability is solved, and low-cost and effective control of the motor current signal is achieved.
[0033] An exemplary embodiment of the present disclosure provides a method for controlling motor current. The process of processing the current signal based on the motor speed using this method is as Figure 1 shown and includes: Step 101: Obtain current control parameters according to the motor speed.
[0034] In this step, the motor speed is obtained, and then according to the preset signal processing conditions, the current control parameters corresponding to the motor speed are obtained.
[0035] According to an exemplary implementation manner, the current control parameters at least include the cut-off frequency corresponding to the motor speed.
[0036] Step 102: Process the current signal output by the motor according to the current control parameters.
[0037] This step is as Figure 2 shown and includes: Step 201: Perform peak current sampling on the current output by the motor to obtain a first current signal.
[0038] In this step, peak current sampling is performed on the current signal output by the motor to obtain the peak value of the current in each period, forming a first current signal.
[0039] Step 202: Filter the first current signal according to the cut-off frequency to obtain a filtered second current signal.
[0040] In this step, the first current signal is filtered to obtain the second current signal. The second current signal, as the actual current signal obtained by measurement, can be further output to the P regulation module in the current control system to generate a control signal for controlling and regulating the current.
[0041] According to an exemplary embodiment, filters such as a first-order filter and a high-pass filter are used to filter the first current signal to obtain the second current signal. The cut-off frequency of the filter is obtained according to the motor speed, and the amplitude of the first current signal is limited through the filter to obtain a more regular and smooth second current signal.
[0042] As Figure 3 shown, it is a waveform schematic of the motor current under a six-step square wave control method. It can be seen from Figure 3 that the noise in the current signal is relatively large. By filtering, the noise therein can be removed, the fluctuation amplitude of the current signal can be reduced, and the current signal can be made more regular.
[0043] An exemplary embodiment of the present disclosure also provides a method for controlling the motor current. The process of obtaining the cut-off frequency according to the motor speed using this method is as Figure 4 shown and includes: Step 401: Obtain the motor speed.
[0044] In this step, the current motor speed can be obtained in real time, and then the current signal is processed based on the motor speed.
[0045] The motor speed can also be obtained when meeting the preset acquisition conditions. For example, taking the switch frequency being lower than a certain threshold value as the acquisition condition, or taking each acquisition period as the acquisition condition to periodically obtain the motor speed.
[0046] Step 402: Obtain the current control parameter corresponding to the motor speed according to the preset signal processing conditions.
[0047] In this step, the current control parameter at least includes the cut-off frequency corresponding to the motor speed.
[0048] In this embodiment, the signal processing conditions at least include a set of correlation relationships between the motor speed and the cut-off frequency. According to an exemplary embodiment, a motor speed value or a motor speed value range is associated with a cut-off frequency value.
[0049] By presetting the correlation relationship between the motor speed and the cut-off frequency, during the operation of the motor, the matching cut-off frequency can be quickly obtained according to the motor speed, and then the current signal can be processed.
[0050] An exemplary embodiment of the present invention further provides a method for controlling motor current, which generates signal processing conditions for processing current signals during the operation of the motor. The specific process is as follows: Generate the signal processing conditions according to the quality of the filtered signal obtained at different cut-off frequency values based on the motor speed. The signal processing conditions include multiple pairs of corresponding relationships between the motor speed and the cut-off frequency.
[0051] According to an exemplary embodiment, the signal processing conditions include multiple sets of association relationships between motor speed values / motor speed value ranges and cut-off frequency values. Different motor speed values / motor speed value ranges correspond to different cut-off frequencies, and higher motor speed values / motor speed value ranges correspond to higher cut-off frequencies.
[0052] According to an exemplary embodiment, the current signals at different motor speeds are monitored respectively. Specifically, the cut-off frequencies can be adjusted at the same motor speed to filter the telecommunication signals, and the preferred cut-off frequency at this motor speed can be determined according to the quality of the filtered current signal (such as the amplitude of current fluctuation, etc.). The current signal data obtained at different motor speeds and different cut-off frequencies can be collected and fitted multiple times to obtain the cut-off frequencies associated with different motor speeds. As Figure 5 shown, it is a schematic diagram of the relationship between speed and cut-off frequency, where the horizontal axis is the speed n and the vertical axis is the cut-off frequency f. From Figure 5 it can be seen that as the speed increases, the cut-off frequency also increases. According to an exemplary embodiment, the growth rate of the cut-off frequency gradually slows down as the speed increases.
[0053] An exemplary embodiment of the present disclosure further provides a method for controlling motor current, which processes the current signal during the current control process. The specific process is as Figure 6 shown, including: Step 601, generate a speed error signal.
[0054] In this step, by comparing the motor target speed (Ref) carried in the speed command and the speed feedback (Rpm) of the actual speed, a speed error signal is generated.
[0055] Step 602, perform proportional-integral (PI) controller adjustment, In this step, a closed-loop control is performed through the PI controller to generate a control signal.
[0056] Step 603, filter the current signal.
[0057] In this step, first, sample the peak current of the current signal to obtain a first current signal (Current). Based on the motor speed, obtain the corresponding cut-off frequency and apply it to the filter. Input the first current signal into the filter (f) for filtering to obtain a second current signal (fCurrent).
[0058] Step 604, generate an error signal.
[0059] In this step, compare the second current signal with the current limit (CurrentLimit) to generate an error signal.
[0060] Step 605, perform proportional regulator (P-regulator) adjustment.
[0061] In this step, based on the error signal, use the P-regulator to adjust the control signal, and obtain and output a final control signal including information such as the signal duty cycle (Duty).
[0062] An exemplary embodiment of the present invention further provides a motor current control device, the structure of which is as Figure 7 shown, including: A parameter configuration module 701, configured to obtain current control parameters according to the motor speed.
[0063] A current control module 702, configured to process the current signal output by the motor according to the current control parameters.
[0064] Further, the parameter configuration module 701 is as Figure 8 shown, including: A speed acquisition sub-module 801, configured to acquire the motor speed.
[0065] A parameter acquisition sub-module 802, configured to acquire the current control parameters corresponding to the motor speed according to preset signal processing conditions, where the current control parameters at least include the cut-off frequency corresponding to the motor speed.
[0066] Further, the structure of the speed acquisition sub-module 801 is as Figure 9 shown, including: A first speed acquisition sub-module 901, configured to acquire the current motor speed; A second speed acquisition sub-module 902, configured to acquire the motor speed when meeting the preset acquisition conditions.
[0067] Further, the structure of the current control module 702 is as Figure 10 shown, including: A current sampling sub-module 1001, configured to perform peak current sampling on the current output by the motor to obtain a first current signal; The first filtering sub-module 1002 is configured to filter the first current signal according to the cut-off frequency to obtain a filtered second current signal.
[0068] The above device can be integrated into a device control system including a motor, and the corresponding functions are implemented by the control system. Regarding the device in the above embodiments, the specific manners in which each module performs operations have been described in detail in the embodiments related to the method, and will not be elaborated herein.
[0069] An exemplary embodiment of the present invention further provides a computer device, including: A processor; A memory for storing instructions executable by the processor; Wherein, the processor is configured to: Obtain current control parameters according to the motor speed; Process the current signal output by the motor according to the current control parameters.
[0070] An exemplary embodiment of the present invention further provides a non-transitory computer-readable storage medium. When the instructions in the storage medium are executed by the processor of a mobile terminal, the mobile terminal can execute a method for controlling motor current. The method includes: Obtain current control parameters according to the motor speed; Process the current signal output by the motor according to the current control parameters.
[0071] Embodiments of the present disclosure provide a method and device for controlling motor current. Current control parameters are obtained according to the motor speed, and then the current signal output by the motor is processed based on the current control parameters. On the premise of analyzing the correlation between the motor speed and the current, a solution for selecting a current signal processing strategy based on the motor speed is proposed, which solves the problem of poor current control stability and realizes low-cost and effective control of the motor current signal.
[0072] In the six-step square wave control mode, noise in the motor current signal is effectively shielded, and the motor current signal is controlled within a safe range, ensuring smooth and safe operation of the motor drive device.
[0073] Those skilled in the art can also understand that the various illustrative logical blocks and steps listed in the embodiments of the present application can be implemented by electronic hardware, computer software, or a combination of both. Whether such a function is implemented by hardware or software depends on the specific application and the design requirements of the entire system. Those skilled in the art can use various methods to implement the described function for each specific application, but such implementation should not be construed as exceeding the scope protected by the embodiments of the present application.
[0074] In addition, the word "exemplary" is used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as "exemplary" is not necessarily to be understood as being advantageous compared to other aspects or designs. Instead, the use of the word exemplary is intended to present concepts in a concrete manner. As used herein, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or". That is, unless otherwise specified or clear from the context, "X applies A or B" is intended to mean any arrangement in a natural inclusive arrangement. That is, if X applies A; X applies B; or X applies both A and B, then "X applies A or B" is satisfied in any of the foregoing instances. Additionally, unless otherwise specified or clear from the context referring to the singular form, the articles "a" and "an" as used in this application and the appended claims are generally understood to mean "one or more".
[0075] Similarly, although the present disclosure has been shown and described with respect to one or more implementations, those skilled in the art will envision equivalent variations and modifications after reading and understanding this specification and the drawings. The present disclosure includes all such modifications and variations and is limited only by the scope of the claims. Specifically with respect to the various functions performed by the components (e.g., elements, resources, etc.) described above, unless otherwise indicated, the terms used to describe such components are intended to correspond to any component (functionally equivalent) that performs the specific function of the described component, even if not structurally equivalent to the disclosed structure. Additionally, although a particular feature of the present disclosure may have been disclosed with respect to only one of several implementations, such a feature may be combined with one or more other features of other implementations as may be desired and advantageous for any given or particular application. Furthermore, with respect to the use of "comprises", "has", "includes", "owns", or variations thereof in the detailed description or claims, such terms are intended to be inclusive in a manner similar to the term "includes".
[0076] Other embodiments of the present disclosure will be readily apparent to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include known or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of the present disclosure are pointed out by the following claims.
[0077] It should be understood that the present disclosure is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present disclosure is only limited by the appended claims.
Claims
1. A method for controlling motor current, characterized in that, including: obtaining a current control parameter according to the motor speed; processing the current signal output by the motor according to the current control parameter.
2. The motor current control method according to claim 1, wherein, The step of obtaining a current control parameter according to the motor speed includes: obtaining the motor speed; obtaining the current control parameter corresponding to the motor speed according to a preset signal processing condition, where the current control parameter at least includes a cut-off frequency corresponding to the motor speed.
3. The motor current control method according to claim 2, wherein The step of obtaining the motor speed includes: obtaining the current motor speed; or, obtaining the motor speed when a preset obtaining condition is met.
4. The motor current control method according to claim 2, characterized in that The step of processing the current signal output by the motor according to the current control parameter includes: performing peak current sampling on the current output by the motor to obtain a first current signal; filtering the first current signal according to the cut-off frequency to obtain a filtered second current signal.
5. The motor current control method according to claim 2, wherein The method further includes: generating the signal processing condition according to the filtered signal quality obtained when the motor speed is below different cut-off frequency values, where the signal processing condition includes multiple pairs of corresponding relationships between the motor speed and the cut-off frequency.
6. A motor current control device, characterized in that, including: a parameter configuration module for obtaining a current control parameter according to the motor speed; a current control module for processing the current signal output by the motor according to the current control parameter.
7. The motor current control device according to claim 6, characterized in that, The parameter configuration module includes: a speed obtaining sub-module for obtaining the motor speed; a parameter obtaining sub-module for obtaining the current control parameter corresponding to the motor speed according to a preset signal processing condition, where the current control parameter at least includes a cut-off frequency corresponding to the motor speed.
8. The motor current control device according to claim 7, characterized in that, The speed obtaining sub-module includes: a first speed obtaining sub-module for obtaining the current motor speed; a second speed obtaining sub-module for obtaining the motor speed when a preset obtaining condition is met.
9. The motor current control device according to claim 7, wherein The current control module includes: a current sampling sub-module for performing peak current sampling on the current output by the motor to obtain a first current signal; a first filtering sub-module for filtering the first current signal according to the cut-off frequency to obtain a filtered second current signal.
10. A computer device, characterized in that, including: a processor; a memory for storing processor-executable instructions; wherein, the processor is configured to: obtain a current control parameter according to the motor speed; process the current signal output by the motor according to the current control parameter.