Axial flux motor and method of step control thereof

Abstract

The application discloses an axial flux motor and a stepping control method thereof, and adopts a stepping control mode to realize accurate control of the motor. By acquiring operation parameters of the axial flux motor, initial angle and stepping angle of the axial flux motor are determined, and then the energization period of the axial flux motor is determined, a stator excitation waveform image is drawn, three-phase current for controlling the axial flux motor is generated, and the PWL function is used to realize stepping rotation of the axial flux motor. The technical scheme has the advantages of high precision, the rotation angle and speed of the axial flux motor are accurately controlled by controlling the number and frequency of current pulses, high-precision position positioning and motion control are realized, and the axial flux motor is suitable for application occasions such as communication and data transmission gimbals as a driving motor.

Description

An axial flux motor and its stepper control method Technical Field

[0001] This invention relates to the field of axial flux motor technology, and more specifically, to an axial flux motor and its stepping control method. Background Technology

[0002] With the rapid development of technology, industrial automation and intelligent manufacturing have become the backbone of modern manufacturing, leading the industry towards greater efficiency and intelligence. Against this backdrop, the performance improvement and optimization of motors, as key components of power systems, are crucial for the stable operation and efficiency of the entire system. Axial flux motors possess advantages such as small size, high torque, high power density, high efficiency, and precise positioning, making them suitable as drive motors for communication and data transmission PTZ devices. Furthermore, axial flux motors also play a key role in precision instrument manufacturing, electric vehicles, and other fields.

[0003] However, traditional control methods for axial flux motors cannot achieve precise stepping control. To improve the position positioning and motion control accuracy of axial flux motors, optimizing the control method is of great significance for precisely controlling the rotation angle and speed of the axial flux motor by controlling the number and frequency of current pulses. Summary of the Invention

[0004] In view of this, the present invention provides an axial flux motor and a control method for the axial flux motor to achieve step control of the axial flux motor and effectively improve control accuracy.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: an axial flux motor, comprising: a housing, a stator portion, and a rotor portion, wherein,

[0006] The housing includes a cavity, and the stator portion and the rotor portion are placed inside the cavity;

[0007] The stator section includes stator coils and stator core, wherein the stator core is disc-shaped and is composed of an iron disc made of a wound iron core;

[0008] The rotor section includes a rotor shaft, magnets, and rotor permanent magnets. The rotor shaft passes through both sides of the cavity and is rotatably connected to the housing. The magnets are solid steel discs, and the rotor permanent magnets are made of neodymium iron boron permanent magnet material and embedded in the solid steel discs. The magnets and the rotor permanent magnets are disposed in the cavity and sleeved on the rotor shaft, and are fixedly connected to the rotor shaft.

[0009] The stator coil is a toroidal winding made of epoxy resin.

[0010] A stepper control method for an axial flux motor, the method comprising the following steps:

[0011] S1: Obtain the operating parameters of the axial flux motor, including the rated speed, the initial angle of the motor, and the step angle of the motor;

[0012] S2: Based on the operating parameters of the axial flux motor, set the energizing pulse time of the three-phase stator coil, and determine the energizing cycle of the axial flux motor based on the energizing pulse time of the three-phase stator coil.

[0013] S3: Draw the stator excitation waveform image and use the PWL function to set the stator excitation waveform as the excitation of the axial flux motor, determine the energizing sequence of phases A, B and C of the axial flux motor, and then generate the three-phase current for controlling the axial flux motor.

[0014] Furthermore, S1 includes:

[0015] S11: Determine the initial angle of the axial flux motor based on the force equilibrium position of the magnetic field of the axial flux motor according to the power supply mode of the axial flux motor.

[0016] S12: Determine the step angle of the axial flux motor based on the number of poles and the number of stator teeth of the axial flux motor.

[0017] Furthermore, determining the initial angle of the axial flux motor based on its rotational force equilibrium position includes:

[0018] Taking phase C as an example, the two adjacent teeth of the stator of the axial flux motor are phase C+ and phase C-. Since phase C+ provides counterclockwise torque to the rotor and phase C- provides clockwise torque to the rotor, when the distance between phase C+ and the rotor permanent magnet is the same as the distance between phase C- and the rotor permanent magnet, the adjacent rotor permanent magnets are subjected to the same force, which is the position of force equilibrium of the magnetic field of the axial flux motor. The rotation angle when the rotor part of the axial flux motor rotates from the initial position to the position of force equilibrium of the magnetic field is the initial angle.

[0019] Further, determining the step angle of the axial flux motor includes:

[0020] The step angle of the axial flux motor depends on the number of poles and the number of stator teeth of the axial flux motor. When the axial flux motor rotates by one step angle, the power supply of the next phase is changed. At this time, the rotor permanent magnet is required to still be in the equilibrium position. By rotating the axial flux motor, the rotor permanent magnet is in the next equilibrium position when the axial flux motor rotates from the initial position by a certain angle. This rotation angle is set as the step angle of the axial flux motor.

[0021] Furthermore, the energizing period of the axial flux motor is determined based on the energizing time of the three-phase stator coils, wherein,

[0022] The rotational speed of the axial flux motor is set, and the angular velocity of the axial flux motor is obtained. Based on the step angle and angular velocity of the axial flux motor, the energizing time of each phase is determined according to formula (1).

[0023] (1),

[0024] In formula (1), This represents the step angle of the axial flux motor. The angular velocity of the axial flux motor is given by supplying power to phases A+, A-, B+, B-, C+, and C- respectively during one energizing cycle, thereby determining one energizing cycle of the axial flux motor.

[0025] Furthermore, step S3 specifically includes:

[0026] S31: Determine the time and value pairs required to plot the stator excitation waveform;

[0027] S32: Based on the time and value pairs determined in S31, draw a rectangular wave that reaches its peak value sequentially in time and has the same duty cycle based on one energizing cycle. Define it as the stator excitation waveform of the PWL function, which serves as the stator current excitation of the axial flux motor in one cycle.

[0028] S33: Set the PWL function as the stator excitation of the axial flux motor, determine the energizing sequence of the three phases of the axial flux motor according to the stator excitation waveform, and then obtain the three-phase current for controlling the axial flux motor.

[0029] By adopting the above technical solution, this invention achieves stepper control of an axial flux motor. Compared with the prior art, the advantages of this invention are: by plotting the stator excitation waveform image, the stator excitation waveform is set as the excitation of the axial flux motor using the PWL function, thereby generating a three-phase current for controlling the axial flux motor. By controlling the number and frequency of current pulses, the rotation angle and speed of the axial flux motor are precisely controlled, thereby improving the position positioning and motion control accuracy of the axial flux motor. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 is a schematic diagram of the structure of the axial flux motor according to an embodiment of the present invention;

[0032] Figure 2 is a flowchart of the core steps of the axial flux motor control method according to an embodiment of the present invention. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0034] The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0035] As shown in Figure 1, an axial flux motor includes: a housing 1, a stator portion T1, and a rotor portion T2, wherein...

[0036] The housing 1 includes a cavity 7; the stator part and the rotor part are placed in the cavity, the stator part T1 includes a stator coil 2 and a stator core 3; the rotor part T2 includes a rotor shaft 6, a magnet 4 and a permanent magnet 5.

[0037] Specifically, the stator core is disc-shaped and consists of an iron disc made of a wound core; the stator coil is a ring-shaped winding made of epoxy resin material.

[0038] Specifically, the rotor shaft passes through both sides of the cavity, the rotor shaft is rotatably connected to the housing, the magnet is composed of a solid steel disc, and the permanent magnet is composed of neodymium iron boron permanent magnet material and embedded in the solid steel disc.

[0039] Specifically, the magnet and the permanent magnet are disposed in the cavity and sleeved on the rotor shaft, and are fixedly connected to the rotor shaft.

[0040] Based on the axial flux motor provided in the above embodiments, this application also provides a stepper control method for an axial flux motor, comprising the following steps:

[0041] S1: Obtain the operating parameters of the axial flux motor, including the rated speed, the initial angle of the motor, and the step angle of the motor;

[0042] S2: Based on the operating parameters of the axial flux motor, set the energizing pulse time of the three-phase stator coil, and determine the energizing cycle of the axial flux motor based on the energizing pulse time of the three-phase stator coil.

[0043] S3: Based on Ansys Maxwell, the stator excitation waveform image is plotted, and the PWL function is used to set the stator excitation waveform as the excitation of the axial flux motor. The energizing sequence of phases A, B and C of the axial flux motor is determined, and then the three-phase current for controlling the axial flux motor is generated.

[0044] Figure 2 illustrates the key steps of the axial flux motor control method of this embodiment.

[0045] S1 includes:

[0046] S11: Determine the initial angle of the axial flux motor based on the force equilibrium position of the magnetic field of the axial flux motor according to the power supply mode of the axial flux motor.

[0047] S12: Determine the step angle of the axial flux motor based on the number of poles and the number of stator teeth of the axial flux motor.

[0048] Specifically, the initial angle of the axial flux motor is determined based on the rotational force equilibrium position of the axial flux motor, including:

[0049] Taking phase C as an example, the two adjacent teeth of the stator of the axial flux motor are phase C+ and phase C-. Since phase C+ provides counterclockwise torque to the rotor and phase C- provides clockwise torque to the rotor, when the distance of phase C+ relative to the rotor permanent magnet is the same as the distance of phase C- relative to the rotor permanent magnet, the adjacent rotor permanent magnets are subjected to the same force, which is the position of force equilibrium of the magnetic field of the axial flux motor. The rotation angle when the rotor part of the axial flux motor rotates from the initial position to the position of force equilibrium of the magnetic field is the initial angle.

[0050] Specifically, in step S12, the step angle of the axial flux motor is determined, wherein...

[0051] The step angle of the axial flux motor depends on the number of poles and the number of stator teeth of the axial flux motor. When the axial flux motor rotates by one step angle, the power supply of the next phase is changed. At this time, the rotor permanent magnet is required to still be in the equilibrium position. By rotating the axial flux motor model, it is found that when the axial flux motor rotates from the initial position by a certain angle, the rotor permanent magnet is exactly in the next equilibrium position. Therefore, this rotation angle is set as the step angle of the axial flux motor.

[0052] Specifically, in S2, the energizing period of the axial flux motor is determined based on the energizing time of the three-phase stator coils, wherein...

[0053] The rotational speed of the axial flux motor is set, and the angular velocity of the axial flux motor is obtained. Based on the step angle and angular velocity of the axial flux motor, the energizing time T of each phase is determined according to formula (1).

[0054] (1),

[0055] In formula (1), This represents the step angle of the axial flux motor. The angular velocity of the axial flux motor is given by supplying power to phases A+, A-, B+, B-, C+, and C- respectively during one energizing cycle, thereby determining one energizing cycle of the axial flux motor.

[0056] Specifically, S3 includes:

[0057] S31: Determine the time and value pairs required to plot the stator excitation waveform;

[0058] S32: Based on the time and value pairs determined in S31, in the Ansys Maxwell simulation software, a rectangular wave with the same duty cycle that reaches its peak value in time sequence is drawn based on one energizing cycle. This is defined as the stator excitation waveform of the PWL function and serves as the stator current excitation of the axial flux motor in one cycle.

[0059] S33: Set the PWL function as the stator excitation of the axial flux motor, determine the energizing sequence of the three phases of the axial flux motor according to the stator excitation waveform, and then obtain the three-phase current for controlling the axial flux motor.

[0060] This embodiment achieves step control of the axial flux motor by sequentially energizing the three-phase stator coils and utilizing the magnetic field generated around the stator coils to interact with the magnetic field of the permanent magnet on the rotor.

[0061] This embodiment precisely controls the rotation angle and speed of the axial flux motor by controlling the number and frequency of current pulses, achieving high-precision position positioning and motion control.

[0062] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0063] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A stepper control method for an axial flux motor, characterized in that, The method includes the following steps: S1: Obtain the operating parameters of the axial flux motor, including the rated speed, the initial angle of the motor, and the step angle of the motor; S2: Based on the operating parameters of the axial flux motor, set the energizing pulse time of the three-phase stator coils, and determine the energizing cycle of the axial flux motor based on the energizing pulse time of the three-phase stator coils; S3: Plot the stator excitation waveform image, and use the PWL function to set the stator excitation waveform as the excitation of the axial flux motor, determine the energizing sequence of phases A, B, and C of the axial flux motor, and then generate three phases for controlling the axial flux motor. Phase current; S3 specifically includes: S31: determining the time and value pairs required to draw the stator excitation waveform; S32: based on the time and value pairs determined in S31, drawing a rectangular wave with the same duty cycle that reaches its peak value in time sequence based on one energizing cycle, defined as the stator excitation waveform of the PWL function, as the stator current excitation of the axial flux motor in one cycle; S33: setting the PWL function as the stator excitation of the axial flux motor, determining the energizing sequence of the three phases of the axial flux motor based on the stator excitation waveform, and thus obtaining the three-phase current used to control the axial flux motor.

2. The stepping control method for an axial flux motor according to claim 1, characterized in that, S1 includes: S11: Determining the initial angle of the axial flux motor based on the force balance position of the magnetic field of the axial flux motor according to the power supply mode of the axial flux motor; S12: Determining the step angle of the axial flux motor according to the number of poles and the number of stator teeth of the axial flux motor.

3. The stepping control method for an axial flux motor according to claim 2, characterized in that, The determination of the initial angle of the axial flux motor based on the rotational force balance position of the axial flux motor includes: taking phase C as an example, the two adjacent teeth of the stator of the axial flux motor are phase C+ and phase C-. Since phase C+ provides counterclockwise torque to the rotor and phase C- provides clockwise torque to the rotor, when the distance of phase C+ relative to the rotor permanent magnet is the same as the distance of phase C- relative to the rotor permanent magnet, the adjacent rotor permanent magnets are subjected to the same force, which is the force balance position of the axial flux motor magnetic field. The rotation angle when the rotor part of the axial flux motor rotates from the initial position to the force balance position of the magnetic field is the initial angle.

4. The stepper control method for an axial flux motor according to claim 3, characterized in that, Determining the step angle of the axial flux motor includes: the step angle of the axial flux motor depends on the number of poles and the number of stator teeth of the axial flux motor. When the axial flux motor rotates by one step angle, the power supply of the next phase is changed. At this time, it is required that the rotor permanent magnet is still in the equilibrium position. By rotating the axial flux motor, when the axial flux motor rotates from the initial position by a certain angle, the rotor permanent magnet is in the next equilibrium position. This rotation angle is set as the step angle of the axial flux motor.

5. The stepper control method for an axial flux motor according to claim 2, characterized in that, The energizing period of the axial flux motor is determined based on the energizing time of the three-phase stator coils. Specifically, the rotational speed of the axial flux motor is set, and its angular velocity is obtained. Based on the step angle and angular velocity of the axial flux motor, the energizing time of each phase is determined according to formula (1). (1), in formula (1), This represents the step angle of the axial flux motor. The angular velocity of the axial flux motor is given by supplying power to phases A+, A-, B+, B-, C+, and C- respectively during one energizing cycle, thereby determining one energizing cycle of the axial flux motor.

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