Permanent magnet synchronous motor parameter identification method and device

Abstract

The embodiment of the application discloses a permanent magnet synchronous motor parameter identification method, which comprises the following steps: obtaining a current curve of a current loop of a stepping motor; obtaining a first area according to a closed area formed by the current curve of the current loop and a preset current sine wave curve; obtaining a step coefficient according to the first area; obtaining a current transformation function according to the step coefficient; and adjusting the current of the stepping motor according to the current transformation function. The embodiment of the application also discloses a permanent magnet synchronous motor parameter identification device.

Description

Technical Field

[0001] This invention relates to the field of motor parameter identification technology, and in particular to a method and apparatus for identifying parameters of a permanent magnet synchronous motor. Background Technology

[0002] Stepper motors are generally used in low-speed, high-torque applications. In scenarios where precise positioning is not required, stepper motors typically use 4- or 8-step square wave drives. This results in low positioning resolution but high torque at high speeds. In scenarios requiring precise positioning, stepper motors generally use sufficiently finely subdivided sine waves. This provides high positioning resolution but lower torque at high speeds. In current technology, the sine wave cannot linearly transition to a square wave as the rotational speed increases, leading to inaccurate positioning at low speeds. Furthermore, when the stepper motor is at high speeds, its torque output characteristics are not stable enough, making it impossible to balance precise positioning with high torque at high speeds. Summary of the Invention

[0003] Based on this, it is necessary to propose a method and device for parameter identification of permanent magnet synchronous motors to address the above problems.

[0004] A method for identifying parameters of a permanent magnet synchronous motor, the method comprising:

[0005] Obtain the current curve of the current loop of the stepper motor;

[0006] The first area is obtained by the enclosed area formed by the current curve of the current loop and the sinusoidal curve of the preset current.

[0007] The step coefficient is obtained based on the first area;

[0008] The current transformation function is obtained based on the step coefficient; and...

[0009] Adjust the current of the stepper motor according to the current transformation function.

[0010] Optionally, the step value coefficient includes an actual value and a set value, wherein the actual value is the value of the first area and the set value is 0.

[0011] Optionally, the step value coefficient is reset when setting the current switching direction.

[0012] Optionally, the step coefficient of the rising segment of the current curve is greater than 0.

[0013] Optionally, the current transformation function is obtained based on the step coefficient, specifically according to the following formula (1):

[0014]

[0015] Among them, S i S-PID-O is the current transformation function for the stepper motor, where S-PID-O is the step coefficient. I-MAX represents the sinusoidal curve of the preset current, where I-MAX is the maximum value of the preset current.

[0016] A parameter identification device for a permanent magnet synchronous motor, the device comprising:

[0017] Acquisition module: Used to acquire the current curve of the current loop of the stepper motor;

[0018] Area calculation module: used to obtain the first area based on the enclosed area formed by the current curve of the current loop and the sine wave curve of the preset current.

[0019] Coefficient calculation module: used to obtain the step coefficient based on the first area;

[0020] Function calculation module: used to obtain the current transformation function based on the step coefficient; and,

[0021] Adjustment module: Used to adjust the current of the stepper motor according to the current transformation function.

[0022] Optionally, the step value coefficient includes an actual value and a set value, wherein the actual value is the value of the first area and the set value is 0.

[0023] Optionally, the step value coefficient is reset when setting the current switching direction.

[0024] Optionally, the step coefficient of the rising segment of the current curve is greater than 0.

[0025] Optionally, the current transformation function is obtained based on the step coefficient, specifically according to the following formula (1):

[0026]

[0027] Among them, S i S-PID-O is the current transformation function for the stepper motor, where S-PID-O is the step coefficient. I-MAX represents the sinusoidal curve of the preset current, where I-MAX is the maximum value of the preset current.

[0028] The embodiments of the present invention have the following beneficial effects: In a method for identifying parameters of a permanent magnet synchronous motor, the current curve of the current loop of the stepper motor is obtained to determine whether the currently used motor uses a 4-step square wave drive or an 8-step square wave drive. Further, a first area is obtained based on the current curve of the current loop and the sine wave curve of the preset current; a step coefficient is obtained based on the first area; and a current transformation function is obtained based on the step coefficient. Finally, the current of the stepper motor is adjusted according to the current transformation function. This ensures that the sine wave of the motor steadily and linearly transitions to a square wave as the speed increases, thereby making the positioning of the stepper motor more accurate at low speeds. Furthermore, when the stepper motor is at high speeds, the torque output characteristics of the stepper motor are ensured to be sufficiently stable, achieving a balance between accurate positioning and high torque at high speeds, thus improving the working performance of the stepper motor. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] in:

[0031] Figure 1 This is a flowchart of the permanent magnet synchronous motor parameter identification method in the first embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram of the first area in the first embodiment of the present invention;

[0033] Figure 3 This is a schematic diagram of the current in the permanent magnet synchronous motor parameter identification method in the first embodiment of the present invention;

[0034] Figure 4 This is a schematic diagram of the current in the permanent magnet synchronous motor parameter identification method in the first embodiment of the present invention;

[0035] Figure 5 This is a schematic diagram of the permanent magnet synchronous motor parameter identification device in the first embodiment of the present invention;

[0036] Figure 6 This is a schematic diagram of a computer device in the first embodiment of the present invention. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] The working principle of a stepper motor is actually the same as that of an electromagnet. It is an open-loop control stepper motor component that converts electrical pulse signals into angular or linear displacement. By controlling the sequence, frequency, and number of electrical pulses applied to the motor coil, the direction, speed, and rotation angle of the stepper motor can be controlled. With the help of a linear motion actuator or gearbox, more complex and precise linear motion control requirements can be achieved.

[0039] A stepper motor typically consists of front and rear end covers, bearings, a central shaft, a rotor core, a stator core, a stator assembly, corrugated washers, screws, and other components. Also called a stepper motor, it utilizes electromagnetic principles to convert electrical energy into mechanical energy, driven by coils wound around the stator teeth. Normally, a coiled metal wire is called a solenoid, while in a motor, the wire wound around the stator teeth is called a winding, coil, or phase. The direction of the motor's operation is related to the phase sequence of the energized circuit; changing the phase sequence changes the direction of operation. Each input pulse signal causes the rotor to rotate by an angle or move forward one step. The output angular or linear displacement is proportional to the number of input pulses, and the rotational speed is proportional to the pulse frequency. The motor's speed is related to the frequency of phase sequence switching; the faster the switching, the faster the motor rotates.

[0040] Please refer to the following: Figure 1 This is a flowchart of the permanent magnet synchronous motor parameter identification method in the first embodiment of the present invention. Specifically, the permanent magnet synchronous motor parameter identification method provided in this embodiment includes the following steps.

[0041] Step S101: Obtain the current curve of the stepper motor's current loop. In this embodiment, the current change curve is set during motor operation. However, in actual applications, due to the influence of various electronic components inside the motor, the actual current inside the motor differs from the preset current. Specifically, a current detection device is used to obtain the current curve of the stepper motor's current loop. If there is a need to display the current curve, it is displayed using a display device.

[0042] Step S102: Obtain the first area based on the enclosing area formed by the current curve of the current loop and the sinusoidal curve of the preset current. Please refer to [link / reference needed]. Figure 2Curve 20 is the preset current curve, and broken line 22 is the actual current curve. The closed area formed by curve 20 and broken line 22 is the first area, which is the basis for the parameters adjusted in this embodiment.

[0043] Step S103: Obtain the step coefficient based on the first area. In some feasible embodiments, the step coefficient includes an actual value and a set value, wherein the actual value is the value of the first area, and the set value is 0. Please refer to [reference needed]. Figure 3 The set value is 0, which corresponds to Figure 3 At point 32, the step coefficient is set to 0. This preset current setting helps the motor current quickly switch between large and small currents, and further ensures the accuracy of motor operation.

[0044] In some feasible embodiments, the step factor is reset when the current switching direction is set.

[0045] In some feasible embodiments, the step coefficient of the rising segment of the current curve is greater than 0.

[0046] Step S104: Obtain the current transformation function based on the step coefficient. Specifically, the current transformation function is obtained based on the step coefficient according to the following formula (1):

[0047]

[0048] Among them, S i S-PID-O is the current transformation function for the stepper motor, where S-PID-O is the step coefficient. I-MAX represents the sinusoidal curve of the preset current, where I-MAX is the maximum value of the preset current.

[0049] Step S105: Adjust the current of the stepper motor according to the current transformation function. Figure 3 The current curve shown represents a limit case in this embodiment. In practical applications, the relationship between the preset sinusoidal current curve and the actual current curve is as follows: Figure 4 As shown, curve 41 represents the set current curve, and curve 42 represents the actual current curve. This method aims to make curve 42 as close as possible to curve 41, thereby improving the performance of the stepper motor. All data mentioned in this embodiment are for illustrative purposes only and are not intended to be limiting.

[0050] The embodiments of the present invention have the following beneficial effects: In a method for identifying parameters of a permanent magnet synchronous motor, the current curve of the current loop of the stepper motor is obtained to determine whether the currently used motor uses a 4-step square wave drive or an 8-step square wave drive. Further, a first area is obtained based on the current curve of the current loop and the sine wave curve of the preset current; a step coefficient is obtained based on the first area; and a current transformation function is obtained based on the step coefficient. Finally, the current of the stepper motor is adjusted according to the current transformation function. This ensures that the sine wave of the motor steadily and linearly transitions to a square wave as the speed increases, thereby making the positioning of the stepper motor more accurate at low speeds. Furthermore, when the stepper motor is at high speeds, the torque output characteristics of the stepper motor are ensured to be sufficiently stable, achieving a balance between accurate positioning and high torque at high speeds, thus improving the working performance of the stepper motor.

[0051] This invention provides a permanent magnet synchronous motor parameter identification device 60, which includes an acquisition module 610, an area calculation module 620, a coefficient calculation module 630, a function calculation module 640, and an adjustment module 650.

[0052] Acquisition module 610: Used to acquire the current curve of the stepper motor's current loop. In this embodiment, the current change curve is set during motor operation. However, in actual applications, due to the influence of various electronic components inside the motor, the actual current inside the motor differs from the preset current. Specifically, a current detection device is used to acquire the current curve of the stepper motor's current loop. If there is a need to display the current curve, it is displayed using a display device.

[0053] Area calculation module 620: Used to obtain a first area based on the enclosed area formed by the current curve of the current loop and the sinusoidal curve of the preset current. Optionally, the step value coefficient includes an actual value and a set value, wherein the actual value is the value of the first area, and the set value is 0. Optionally, the step value coefficient is reset when the current switching direction is set. Optionally, the step coefficient of the rising segment of the current curve is greater than 0. Please refer to [reference needed]. Figure 2 Curve 20 is the preset current curve, and broken line 22 is the actual current curve. The closed area formed by curve 20 and broken line 22 is the first area, which is the basis for the parameters adjusted in this embodiment.

[0054] Coefficient calculation module 630: used to obtain the step coefficient based on the first area. In some feasible embodiments, setting the preset current in this way can help the current in the motor quickly switch between large and small currents, and further, it can also ensure the accuracy of motor operation.

[0055] Function calculation module 640: used to obtain the current transformation function based on the step coefficient. Specifically, the current transformation function is obtained based on the step coefficient according to the following formula (1):

[0056]

[0057] Among them, S i S-PID-O is the current transformation function for the stepper motor, where S-PID-O is the step coefficient. I-MAX represents the sinusoidal curve of the preset current, where I-MAX is the maximum value of the preset current.

[0058] Adjustment module 650: Used to adjust the current of the stepper motor according to the current transformation function. Figure 3 The current curve shown represents a limit case in this embodiment. In practical applications, the relationship between the preset sinusoidal current curve and the actual current curve is as follows: Figure 4 As shown, curve 41 represents the set current curve, and curve 42 represents the actual current curve. This method aims to make curve 42 as close as possible to curve 41, thereby improving the performance of the stepper motor. All data mentioned in this embodiment are for illustrative purposes only and are not intended to be limiting.

[0059] The embodiments of the present invention have the following beneficial effects: In a method for identifying parameters of a permanent magnet synchronous motor, the current curve of the current loop of the stepper motor is obtained to determine whether the currently used motor uses a 4-step square wave drive or an 8-step square wave drive. Further, a first area is obtained based on the current curve of the current loop and the sine wave curve of the preset current; a step coefficient is obtained based on the first area; and a current transformation function is obtained based on the step coefficient. Finally, the current of the stepper motor is adjusted according to the current transformation function. This ensures that the sine wave of the motor steadily and linearly transitions to a square wave as the speed increases, thereby making the positioning of the stepper motor more accurate at low speeds. Furthermore, when the stepper motor is at high speeds, the torque output characteristics of the stepper motor are ensured to be sufficiently stable, achieving a balance between accurate positioning and high torque at high speeds, thus improving the working performance of the stepper motor.

[0060] This invention also provides a computer-readable storage medium storing a computer program. When executed by a processor, the computer program causes the processor to perform the steps of any of the methods described above. Specifically, the program may be stored in a non-volatile computer-readable storage medium. When executed, the program may include the processes described in the embodiments of the methods above. Any references to memory, storage, databases, or other media used in the embodiments provided in this application may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0061] In one embodiment, a computer device is provided, including a memory and a processor, the memory storing a computer program that, when executed by the processor, causes the processor to perform the steps of the above-described permanent magnet synchronous motor parameter identification method.

[0062] Please refer to the following: Figure 6 This is a schematic diagram of the internal structure of a computer device in one embodiment. The computer device 900 includes a memory 910 and a processor 920. The memory 910 stores a computer program, which, when executed by the processor, causes the processor 920 to perform the steps of any of the methods described above.

[0063] The computer device 900 also includes a processor 920, a memory 910, and a network interface 940 connected via a system bus 930. The memory 910 includes a non-volatile storage medium and internal memory. The non-volatile storage medium of the computer device 900 stores an operating system and may also store a computer program. When executed by the processor 920, this computer program enables the processor 920 to implement a permanent magnet synchronous motor parameter identification method. The internal memory 910 may also store a computer program, which, when executed by the processor, enables the processor to perform the permanent magnet synchronous motor parameter identification method.

[0064] The memory 910 includes at least one type of computer-readable storage medium, including flash memory, hard disk, multimedia card, card-type memory (e.g., SD or DX memory), magnetic memory, magnetic disk, optical disk, etc. In some embodiments, the memory 910 can be an internal storage unit of the computer device 900, such as the hard disk of the computer device 900. In other embodiments, the memory 910 can be an external storage device of the computer device 900, such as a plug-in hard disk, smart media card (SMC), secure digital card (SD), flash card, etc., equipped on the computer device 900. Furthermore, the memory 910 can include both internal and external storage units of the computer device 900. The memory 910 can be used not only to store application software and various types of data installed on the computer device 900, such as computer programs for permanent magnet synchronous motor parameter identification methods, but also to temporarily store data that has been output or will be output, such as data generated by the execution of the permanent magnet synchronous motor parameter identification method. In some feasible embodiments, the processor 920 may be a central processing unit (CPU), but it can also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor.

[0065] Specifically, the processor 920 executes a computer program for a permanent magnet synchronous motor parameter identification method to control the computer device 900 to implement the permanent magnet synchronous motor parameter identification method.

[0066] Furthermore, the computer device 900 may also include a system bus 930, which may be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. This bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 6 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0067] Specifically, the computer device 900 may also include a network interface 940. The network interface may optionally include a wired network interface and / or a wireless network interface (such as a Wi-Fi network interface, a Bluetooth network interface, etc.), which is typically used to establish communication connections between the computer device 900 and other devices, such as a communication connection between the computer device 900 and a waveform display device.

[0068] In other feasible embodiments, the computer device 900 may also include a display component (not shown). The display component may be an LED (Light Emitting Diode) display, a liquid crystal display, a touch-sensitive liquid crystal display, or an OLED (Organic Light-Emitting Diode) touchscreen, etc. The display component may also be appropriately referred to as a display device or display unit, used to display information processed in the computer device 900 and to display a visual user interface.

[0069] Figure 6 Only the computer device 900, which includes components 910-940 and a method for identifying parameters of a permanent magnet synchronous motor, is shown. Those skilled in the art will understand that... Figure 6 The structure shown does not constitute a limitation on the computer device 900, and may include fewer or more components than shown, or combine certain components, or have different component arrangements. Since the computer device 900 employs all the technical solutions of the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be repeated here.

[0070] Furthermore, the method according to the present invention can also be implemented as a computer program or computer program product, which includes computer program code instructions for performing some or all of the steps in the above-described method of the present invention.

[0071] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0072] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

[0073] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0074] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for identifying parameters of a permanent magnet synchronous motor, characterized in that, The method includes: Obtain the current curve of the current loop of the stepper motor; The first area is obtained by the enclosed area formed by the current curve of the current loop and the sinusoidal curve of the preset current. The step coefficient is obtained based on the first area; The current transformation function is obtained based on the step coefficient; and... The current of the stepper motor is adjusted according to the current transformation function; The current transformation function is obtained based on the step coefficient, specifically according to the following formula (1): Among them, S i S-PID-O is the current transformation function of the stepper motor, and S-PID-O is the step coefficient. I-MAX represents the sinusoidal curve of the preset current, and I-MAX represents the maximum value of the preset current.

2. The method for identifying parameters of a permanent magnet synchronous motor according to claim 1, characterized in that, The step coefficient includes an actual value and a set value, wherein the actual value is the value of the first area, and the set value is 0.

3. The method for identifying parameters of a permanent magnet synchronous motor according to claim 2, characterized in that, The step coefficient is reset when the current switching direction is set.

4. The method for identifying parameters of a permanent magnet synchronous motor according to claim 3, characterized in that, The step coefficient of the rising segment of the current curve is greater than 0.

5. A parameter identification device for a permanent magnet synchronous motor, characterized in that, The device includes: Acquisition module: Used to acquire the current curve of the current loop of the stepper motor; Area calculation module: used to obtain the first area based on the enclosed area formed by the current curve of the current loop and the sine wave curve of the preset current. Coefficient calculation module: used to obtain the step coefficient based on the first area; Function calculation module: used to obtain the current transformation function based on the step coefficient; and, Adjustment module: used to adjust the current of the stepper motor according to the current transformation function; The function calculation module specifically obtains the current transformation function according to the following formula (1): Among them, S i S-PID-O is the current transformation function of the stepper motor, and S-PID-O is the step coefficient. I-MAX represents the sinusoidal curve of the preset current, and I-MAX represents the maximum value of the preset current.

6. The permanent magnet synchronous motor parameter identification device according to claim 5, characterized in that, The step coefficient includes an actual value and a set value, wherein the actual value is the value of the first area, and the set value is 0.

7. The permanent magnet synchronous motor parameter identification device according to claim 6, characterized in that, The step coefficient is reset when the current switching direction is set.

8. The permanent magnet synchronous motor parameter identification device according to claim 6, characterized in that, The step coefficient of the rising segment of the current curve is greater than 0.

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