A method and system for flux-oriented control of a hysteresis motor rotor

Abstract

The application relates to the technical field of hysteresis motor driving control, and discloses a hysteresis motor rotor flux linkage orientation control method and system, which comprises the following steps: acquiring real-time operation information of a hysteresis motor; determining the spatial position of the rotor flux linkage of the hysteresis motor and taking the spatial position as an orientation reference of a rotating coordinate system to perform coordinate conversion between a stationary coordinate system and the rotating coordinate system, so that the current control axis is dynamically kept consistent with the direction of the rotor flux linkage; performing speed outer loop control and current inner loop control to obtain a current component determined by the current control axis and a control voltage component obtained through closed loop adjustment based on the current component; and converting at least the control voltage component to generate a driving signal for hysteresis motor control. The application introduces the field orientation control idea to perform closed loop vector control on the hysteresis motor, decouples the stator current into independent excitation components and torque components, realizes approximate decoupling control of the flux linkage and the torque, and improves the dynamic performance and control precision of the hysteresis motor.

Description

Technical Field

[0001] This invention relates to the field of hysteresis motor drive control technology, specifically to a hysteresis motor rotor flux orientation control method and system. Background Technology

[0002] Hysteresis motors are a type of AC motor that generates electromagnetic torque by relying on the hysteresis characteristics of the rotor's magnetic material. Their rotors are typically made of semi-hard magnetic materials, eliminating the need for excitation windings or permanent magnets. This results in a simpler structure, higher mechanical reliability, and advantages such as smooth operation, lower vibration, and lower noise.

[0003] Hysteresis motors can be applied in a variety of technical fields with high requirements for operational stability and reliability. In the field of precision equipment, they can be used in timing devices, audio equipment, precision gyroscopes, and spatial optical positioning systems to achieve stable drive and precise control. In the field of medical equipment, they can be used in magnetic resonance imaging equipment and implantable or extracorporeal circulation drive devices. In addition, hysteresis alloy materials have low gas release characteristics and good chemical stability, making them suitable for use in high-cleanliness environments. They are suitable for magnetic levitation platforms in semiconductor manufacturing equipment and high-cleanliness experimental systems, and can also be used in blood-contact drive devices. Hysteresis motors also have application value under high temperature, high pressure, and high speed operating conditions. Their materials have high temperature resistance and mechanical strength, and can be used in electric turbocharging systems and submersible pumps to improve the operational reliability of devices under complex conditions.

[0004] During operation, the rotor magnetization state of a hysteresis motor lags behind the rotating magnetic field of the stator by a certain phase. This hysteresis effect causes a change in the distribution of the air gap magnetic field, thereby generating driving torque. Since this type of motor can generate torque from standstill to synchronous operation, it can usually achieve stable operation without a complex starting control mechanism.

[0005] Currently, hysteresis motors in engineering applications mostly operate using an open-loop power supply method. While this method is simple to implement, it has certain performance limitations. With the development of industrial automation and intelligent manufacturing, the requirements for motor control precision are continuously increasing. Motors need to provide low torque ripple, fast dynamic response, and high steady-state accuracy across the entire speed range. These performance indicators are almost impossible to achieve in open-loop control mode. Specifically: (1) Traditional open-loop hysteresis motors rely solely on their own synchronous torque to resist step loss when the load changes abruptly, resulting in long dynamic recovery time and large oscillation amplitude; (2) When the hysteresis motor is running in open loop, the stator current is determined only by the frequency and voltage, and the excitation and torque components cannot be distinguished. (3) The direction of rotor flux linkage is difficult to obtain, which restricts the application of high-performance control methods.

[0006] With the development of high-performance motor drive technology, especially the increasing demand for high dynamic response, high precision control and adaptation to complex working conditions, hysteresis motors, as another synchronous motor solution that does not rely on permanent magnets, have an undeniable strategic value in the trend of clean energy equipment industry. Traditional open-loop control methods can no longer meet the actual application requirements of hysteresis motors. Summary of the Invention

[0007] The present invention aims to provide a rotor flux orientation control method and system for hysteresis motors to solve the technical problem that traditional open-loop control methods can hardly meet the practical application requirements of hysteresis motors.

[0008] The basic solution provided by this invention is: a rotor flux orientation control method for a hysteresis motor, comprising: Obtain real-time operating information of the hysteresis motor; Determine the spatial position of the rotor flux linkage of the hysteresis motor and use it as the orientation reference of the rotating coordinate system. Perform coordinate transformation between the stationary coordinate system and the rotating coordinate system to dynamically keep the current control axis consistent with the direction of the rotor flux linkage. Perform speed outer loop control and current inner loop control, and obtain the current component determined by the current control axis and the control voltage component obtained by closed loop adjustment based on the current component. At least the control voltage component is converted to generate a drive signal for hysteresis motor control.

[0009] The present invention also provides a hysteresis motor rotor flux orientation control system to execute a hysteresis motor rotor flux orientation control method; the system includes: Hysteresis motor module, used to acquire real-time operating information of hysteresis motor; The flux linkage coordinate transformation module is used to determine the spatial position of the rotor flux linkage of the hysteresis motor and use it as the orientation reference of the rotating coordinate system to perform coordinate transformation between the stationary coordinate system and the rotating coordinate system, so that the current control axis and the rotor flux linkage direction are dynamically kept consistent. The outer and inner loop control modules are used to perform speed outer loop control and current inner loop control, and to obtain the current component determined by the current control axis and the control voltage component obtained by closed-loop adjustment based on the current component. An inverter drive module is used to convert at least the control voltage component into a drive signal for hysteresis motor control.

[0010] The working principle and advantages of this invention are as follows: To address the technical challenge that traditional open-loop control methods are insufficient for the practical application requirements of hysteresis motors, this invention introduces Field-Oriented Control (FOC) to perform closed-loop vector control of the hysteresis motor, which is substantially different from existing open-loop control methods. This invention obtains the real-time spatial position of the rotor flux linkage of the hysteresis motor and uses it as the orientation reference for the rotating coordinate system, ensuring that the current control axis is aligned with the rotor flux linkage direction. Through coordinate transformation and closed-loop adjustment, rotor flux linkage orientation control of the hysteresis motor is achieved. By decoupling the stator current into independent excitation and torque components, approximately decoupled control of flux linkage and torque is achieved, improving the dynamic performance and control accuracy of the hysteresis motor. For example, the torque response can reach the millisecond level (approaching the limit of the motor's mechanical time constant), and the acceleration and deceleration capabilities are extremely strong, making it suitable for scenarios requiring frequent and rapid responses.

[0011] Furthermore, since the rotor flux linkage of a hysteresis motor is formed by the dynamic magnetization of the rotor magnetic material under the action of a rotating magnetic field, its spatial orientation is not only related to the rotor's mechanical position but also affected by hysteresis, load changes, slip state, and magnetization history. This invention addresses the characteristics of hysteresis motor rotor flux linkage, such as dynamic hysteresis, the change of operating point with the hysteresis loop, and the need to maintain appropriate slip during control. It considers the permeability variation of the hysteresis material and the economical asynchronous operation to build a control system, ensuring precise and efficient operation of the hysteresis motor. This provides a better operating environment and input data source for the directional control of the hysteresis motor rotor flux linkage. With the operation of closed-loop control, the performance and accuracy of the directional control of the hysteresis motor rotor flux linkage are further improved. This invention is particularly suitable for hysteresis motors with rotors using semi-hard magnetic materials, including but not limited to iron-chromium-cobalt alloys, AlNiCo alloys, and other magnetic materials with hysteresis characteristics. It exhibits good applicability and robustness across different hysteresis characteristic ranges. Attached Figure Description

[0012] Figure 1 This is a schematic flowchart of a rotor flux orientation control method for a hysteresis motor provided in an embodiment of the present invention; Figure 2 This is a vector diagram showing the magnetic field orientation of a hysteresis motor provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the change in magnetic flux density during the dynamic process of an existing hysteresis motor. Figure 4 This is a schematic diagram comparing the real-time rotor flux linkage angle and the simulated rotor flux linkage angle provided in an embodiment of the present invention; Figure 5 A schematic diagram of the structure of a rotor flux orientation control system for a hysteresis motor provided in an embodiment of the present invention. Figure 1 ; Figure 6 A schematic diagram of the structure of a rotor flux orientation control system for a hysteresis motor provided in an embodiment of the present invention. Figure 2 . Detailed Implementation

[0013] The following detailed explanation illustrates the specific implementation methods: The basic implementation examples are as follows: Figure 1 As shown: A rotor flux orientation control method for a hysteresis motor, comprising: Obtain real-time operating information of the hysteresis motor; Determine the spatial position of the rotor flux linkage of the hysteresis motor and use it as the orientation reference of the rotating coordinate system. Perform coordinate transformation between the stationary coordinate system and the rotating coordinate system to dynamically keep the current control axis consistent with the direction of the rotor flux linkage. Perform speed outer loop control and current inner loop control, and obtain the current component determined by the current control axis and the control voltage component obtained by closed loop adjustment based on the current component. At least the control voltage component is converted to generate a drive signal for hysteresis motor control.

[0014] Specifically: The stator and rotor voltage equations and flux linkage equations of the hysteresis motor in the stationary coordinate system are established. The electromagnetic characteristics of the motor are described by introducing parameters such as stator resistance, rotor equivalent resistance, leakage inductance and mutual inductance. Among them, the flux linkage and current satisfy the coupling relationship. The rotor flux linkage is not only related to the current, but also to the magnetization history of the hysteresis material.

[0015] The stator and rotor voltage equations of the hysteresis motor are as follows: (1) In the formula, u sα , i sα They are respectively α Shaft stator voltage (V), current (A); u sβ , i sβ They are respectively β Shaft stator voltage (V), current (A); u rα , i rα They are respectively α Shaft rotor voltage (V), current (A); u rβ , i rβ They are respectively β Shaft rotor voltage (V), current (A); R s The resistance (Ω) of the stator coil. R r The rotor equivalent resistance (Ω); ψ sα , ψ sβ They are respectively α , β Shaft stator flux linkage (Wb); ψ rα , ψ rβ They are respectively α , β Rotor flux linkage (Wb).

[0016] The mathematical relationships between stator and rotor flux linkages, inductance, and current are as follows: (2) In the formula, L ls The leakage inductance (H) between the stator coils; L m The mutual inductance (H) between the stator and rotor; L hr The mutual inductance (H) is caused by the hysteresis effect of the rotor itself using magnetic materials.

[0017] like Figure 2 As shown, during dynamic operation, the relative phase between the rotor magnetic field and the magnetic flux density of a hysteresis motor changes with the load, causing the operating point of the hysteresis loop to shift. When the load torque is less than the electromagnetic torque, the motor accelerates, the hysteresis loop area decreases, and the electromagnetic torque decreases; when the load torque is greater than the electromagnetic torque, the motor decelerates, the hysteresis loop area increases, and the electromagnetic torque increases. The hysteresis motor achieves torque rebalancing through this dynamic adjustment process of the hysteresis loop. Specifically, as... Figure 2 As shown, the magnetic flux density changes during the dynamic process of the hysteresis motor. Points P and Q on the magnetic flux density distribution curve correspond to the operating points P0 and Q0 on the hysteresis loop L0, respectively. When the motor accelerates, the rotor magnetic field undergoes a positive phase shift relative to the magnetic flux density, and the operating point moves from P0, Q0 to P1, Q1, the hysteresis loop area decreases, and the electromagnetic torque decreases. Conversely, when the motor decelerates, the operating point returns from P1, Q1 to P0, Q0, the hysteresis loop area increases, and the electromagnetic torque increases. The hysteresis motor achieves automatic balance between output torque and load torque through this dynamic change in the hysteresis loop area.

[0018] During the dynamic operation of the hysteresis motor, an asynchronous operation mode is adopted by introducing a dynamic adjustment mechanism for the magnetic field angular velocity. Key parameters in the real-time operating information of the hysteresis motor are dynamically corrected based on the permeability, which reflects the actual magnetization behavior during dynamic operation, thereby obtaining real-time operating information adapted to the actual magnetization behavior of the hysteresis motor. Specifically: To ensure the hysteresis motor always operates at its maximum output torque, the control process maintains the motor in an asynchronous state. In the hysteresis motor modeling process of this invention, the permeability of the rotor hysteresis material is not a fixed constant, but rather a lookup table is established based on measured hysteresis loop data, according to the motor's operating state (magnetic flux density amplitude). B hm Real-time updates of the relative permeability of hysteresis materials μ rh .

[0019] (3) In the formula, B hm The magnetic flux density amplitude, , , All of these are constants related to electrode parameters. μ 0 is the permeability of free space. ε 0 represents the angle by which the electric field strength leads the magnetic flux density of the hysteresis material. μ rs The relative permeability of the stator core, γ 0 represents the angle at which the air gap magnetic flux density lags behind the magnetomotive force. I t This represents the stator current amplitude.

[0020] It should be noted that the test of the main hysteresis loop is conducted according to the national standard GB / T3658—2022. This standard specifies the test method for the magnetic properties of magnetic metallic materials under different frequency conditions. The test principle is as follows: a toroidal sample is used as the main body of the magnetic circuit, and a primary winding and a secondary winding are wound on the sample to form an unloaded transformer structure. During the test, an excitation current is applied to the primary winding. i main And by adjusting the current, the induced voltage on the secondary side is... u sense Then, the BH curve under the corresponding operating condition was recorded, and this is how it was obtained. μ rh And according to equation (3) B hm Go and check the status of this status. μ rh Further simulations were conducted.

[0021] During operation, the corresponding permeability or equivalent magnetization parameter is read from the lookup table based on the current magnetization operating point to characterize the actual magnetization characteristics of the hysteresis material under different magnetic field conditions, and the flux linkage equation uses... L hr The permeability dynamically corresponding to the current magnetization operating point μ rhIt is confirmed that the specific determination method is the existing method. This method can effectively reflect the nonlinearity, magnetization hysteresis, and operating point-related characteristics of hysteresis materials, thereby improving the accuracy of flux linkage calculation and the realism of the model.

[0022] In the initial control phase, a higher magnetic field angular velocity is set to drive the rotor to accelerate. Once the rotor speed reaches the set switching threshold, the magnetic field angular velocity is dynamically adjusted based on the actual rotor angular velocity and the preset slip rate. This ensures that the motor maintains a suitable slip range during stable operation, thereby improving torque output capability. The higher magnetic field angular velocity and the switching threshold are reasonably determined based on the actual operating conditions of the hysteresis motor.

[0023] (4) in, ω cut is the rotor angular velocity at the moment of magnetic field speed switching. ωr For real-time rotor angular velocity, ω 0 represents the given magnetic field angular velocity. s For slippage, ωe The angular velocity of the magnetic field is dynamically adjusted.

[0024] To better illustrate the subsequent process of determining the spatial position of the rotor flux linkage in the hysteresis motor, we will first explain the coordinate system, such as... Figure 3 As shown, α-β It is a stationary two-phase coordinate system. dq It is a rotating coordinate system for rotor flux orientation, where d The shaft and rotor flux linkage are aligned. q Axis perpendicular to d Axis, Vector i s This indicates the stator phase current.

[0025] It should be noted that conventional open-loop control typically measures the magnetic field electrical angle. α Used for Park and inverse Park transformations, as follows: (5) in, ω e Given a constant electric angular velocity.

[0026] The aforementioned magnetic field electrical angle α is preset or integrated by the control system and is essentially an open-loop quantity. However, since the rotor flux linkage of the hysteresis motor is not fixed but dynamically changes with the hysteresis loop and operating state, if the magnetic field electrical angle α is still used as the orientation reference, it cannot be guaranteed that the rotating coordinate system is always aligned with the rotor flux linkage direction, thus leading to... d The deviation between the axis and the direction of the flux linkage affects the decoupling effect between the flux linkage and the torque.

[0027] Unlike traditional control methods for hysteresis motors that directly use the electric angle of the magnetic field α As a coordinate transformation reference, this invention estimates the spatial direction of the rotor flux linkage in real time, and calculates the back electromotive force component (corresponding component in the stationary coordinate system) based on the real-time operating information of the hysteresis motor (sampled motor stator voltage, current, and other signals, i.e., components in the stationary coordinate system). , The rotor flux vector (corresponding component in the stationary coordinate system) is obtained by filtering and integrating the back EMF component. , The rotor flux linkage angle is calculated based on the rotor flux linkage vector, and then smoothed and made continuous using a phase-locked loop or filtering circuit, thereby achieving real-time estimation of the spatial direction of the rotor flux linkage. Specifically: The back EMF component and rotor flux linkage vector in the stationary coordinate system are calculated using the following formulas: (6) (7) In the formula, e For back potential, i s For stator current, u s Stator voltage, L ls For stator leakage, This is the estimated value of the rotor flux linkage.

[0028] The rotor flux linkage angle used for coordinate transformation is calculated using the following formula. : (8) (9) In the formula, In a stationary coordinate system α Estimated rotor flux linkage In a stationary coordinate system β Estimated value of rotor flux linkage.

[0029] With flux angle It replaces the traditional magnetic field electric angle and is used for Park transformation and inverse Park transformation, so that the d-axis is always aligned with the rotor flux direction and the q-axis is orthogonal to it, thereby achieving effective decoupling of flux component and torque component, improving the dynamic response performance and control accuracy of the control system.

[0030] Furthermore, the method for obtaining the flux linkage angle is not limited to the back potential integration method; it can also be estimated using a current model or an observer structure.

[0031] Furthermore, under low-speed or special operating conditions, the flux estimation results can be corrected by combining filtering or observer structures.

[0032] Furthermore, based on the stator and rotor voltage equations and flux linkage equations of the hysteresis motor in the stationary coordinate system, the values ​​in the stationary coordinate system are calculated. α , β Shaft rotor flux linkage, and based on calculations α , β The rotor flux linkage angle is directly calculated using equations (8)-(9) to compare and verify the spatial position of the rotor flux linkage of the hysteresis motor.

[0033] like Figure 4 As shown, the simulation compares the actual rotor flux linkage angle directly obtained through equations (1), (2), (8), and (9) with the rotor flux linkage angle indirectly obtained from the back electromotive force using equations (6)-(9). The trends of both are almost identical, with only minor deviations. The actual rotor flux linkage angle calculated in the simulation is theta_raw, and the rotor flux linkage angle obtained from the back electromotive force is theta_E. Of course, it can also be calculated based on the closed-loop system... Figure 6 In i sq Calculate the difference between the flux linkage angles of the two rotors at the same moment, and then compare the difference with... i sq A compensation function is established using hooks to make the rotor flux linkage angle obtained from the back EMF closer to the actual rotor flux linkage angle. Because in the experiment... i sq Since it is measurable, this method can also be used in specific simulation experiments.

[0034] like Figure 5 and Figure 6 As shown, this embodiment also provides a hysteresis motor rotor flux orientation control system, which executes any of the hysteresis motor rotor flux orientation control methods described above; the system includes: Hysteresis motor module, used to acquire real-time operating information of hysteresis motor; The flux linkage coordinate transformation module is used to determine the spatial position of the rotor flux linkage of the hysteresis motor and use it as the orientation reference of the rotating coordinate system to perform coordinate transformation between the stationary coordinate system and the rotating coordinate system, so that the current control axis and the rotor flux linkage direction are dynamically kept consistent. The outer and inner loop control modules are used to perform speed outer loop control and current inner loop control, and to obtain the current component determined by the current control axis and the control voltage component obtained by closed-loop adjustment based on the current component. An inverter drive module is used to convert at least the control voltage component into a drive signal for hysteresis motor control.

[0035] In practical use, such as Figure 5 As shown: The hysteresis motor module simulates the operation of the hysteresis motor (HM) based on a mathematical model of the hysteresis motor and obtains real-time operating information of the hysteresis motor. Considering the nonlinear magnetization characteristics of the hysteresis material, the permeability parameters of the rotor hysteresis material at different operating points are obtained by looking up table based on measured hysteresis loop data. These permeability parameters are then used for flux linkage calculation or control model updates, enabling the established control method to more accurately reflect the actual magnetization behavior during the dynamic operation of the hysteresis motor. The output hysteresis motor real-time operating information is used to complete the real-time calculation of the rotor flux angle through the flux linkage coordinate transformation module. Based on the rotor flux angle, the transformation between the stationary coordinate system and the rotating coordinate system is realized. The outer loop control of rotational speed and the inner loop control of current are executed through the flux linkage coordinate transformation module. The outer loop speed control compares the setpoint speed with the actual speed and outputs the result in a rotating coordinate system via a PI controller. q Shaft current reference value to adjust electromagnetic torque; The inner current loop is used to transform the sampled current signal into a rotating coordinate system. d shaft and q The shaft current component is regulated separately using closed-loop control to output the control voltage. u d and u q ; The inverter drive module converts at least the control voltage component into a drive signal for hysteresis motor control, obtains new real-time operating information of the hysteresis motor, and repeats the process cyclically.

[0036] Furthermore, it also includes a comparison and verification module, used to calculate the values ​​in the stationary coordinate system based on the stator and rotor voltage equations and flux linkage equations of the hysteresis motor in the stationary coordinate system. α , β Shaft rotor flux linkage, and based on calculations α , β The actual rotor flux linkage angle is calculated by shaft rotor flux linkage calculation, and the spatial position of rotor flux linkage in hysteresis motor is compared and verified.

[0037] This embodiment provides a rotor flux orientation control method and system for a hysteresis motor. It introduces the concept of field orientation control to perform closed-loop vector control on the hysteresis motor. By decoupling the stator current into independent excitation and torque components, it achieves approximately decoupled control of flux and torque, improving the dynamic performance and control accuracy of the hysteresis motor. Furthermore, based on a hysteresis motor operation control mode that reflects the actual magnetization behavior during dynamic operation, it ensures precise and efficient operation of the hysteresis motor, providing a better operating environment and input data source for rotor flux orientation control. With the operation of closed-loop control, the performance and accuracy of rotor flux orientation control of the hysteresis motor are further improved.

[0038] The above descriptions are merely embodiments of the present invention. Commonly known structures and characteristics of the solutions are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are aware of all existing technologies in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, under the guidance of this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the patent.

Claims

1. A method of hysteresis motor rotor flux orientation control, characterized in that, include: Obtain real-time operating information of the hysteresis motor; Determine the spatial position of the rotor flux linkage of the hysteresis motor and use it as the orientation reference of the rotating coordinate system. Perform coordinate transformation between the stationary coordinate system and the rotating coordinate system to dynamically keep the current control axis consistent with the direction of the rotor flux linkage. Perform speed outer loop control and current inner loop control, and obtain the current component determined by the current control axis and the control voltage component obtained by closed loop adjustment based on the current component. At least the control voltage component is converted to generate a drive signal for hysteresis motor control.

2. A hysteresis motor rotor flux oriented control method according to claim 1, characterized in that, The back EMF component is calculated based on the real-time operating information of the hysteresis motor. The rotor flux vector is obtained by filtering and integrating the back EMF component. The rotor flux angle is then calculated based on the rotor flux vector. Using the rotor flux angle as a reference, coordinate transformation is performed between the stationary coordinate system and the rotating coordinate system to ensure that the current control axis and the rotor flux direction are dynamically aligned.

3. The rotor flux orientation control method for a hysteresis motor according to claim 2, characterized in that, The back EMF and rotor flux linkage estimates are calculated using the following formulas, from which the back EMF components and rotor flux linkage vector in the stationary coordinate system are calculated: in, e It is the back potential; i s For stator current, u s Stator voltage, L ls For stator leakage, This is the estimated value of the rotor flux linkage; The rotor flux linkage angle is calculated using the following formula. : in, In the stationary coordinate system α Estimated rotor flux linkage on shaft In a stationary coordinate system β Estimated value of rotor flux linkage.

4. The rotor flux orientation control method for a hysteresis motor according to claim 1, characterized in that, During the dynamic operation of the hysteresis motor, an asynchronous operation mode is adopted by introducing a dynamic adjustment mechanism for the magnetic field angular velocity. Based on the permeability that reflects the actual magnetization behavior of the hysteresis motor during dynamic operation, the key parameters in the real-time operation information of the hysteresis motor are dynamically corrected to obtain real-time operation information that is adapted to the actual magnetization behavior of the hysteresis motor.

5. The rotor flux orientation control method for a hysteresis motor according to claim 4, characterized in that, Once the rotor speed reaches the set switching threshold, the magnetic field angular velocity is dynamically adjusted using the following formula: in, ωe For dynamically adjusted magnetic field angular velocity, ω cut is the rotor angular velocity at the moment of magnetic field speed switching. ωr For real-time rotor angular velocity, ω 0 represents the given magnetic field angular velocity. s This refers to the slippage rate.

6. The rotor flux orientation control method for a hysteresis motor according to claim 4, characterized in that, The dynamic determination process of magnetic permeability includes: during operation, the corresponding magnetic permeability is dynamically read from the lookup table according to the current magnetization operating point; wherein, the lookup table is established based on the measured hysteresis loop data, and the relative magnetic permeability of the hysteresis material is updated in real time according to the magnetic flux density amplitude in the motor operating state.

7. The rotor flux orientation control method for a hysteresis motor according to claim 6, characterized in that, Relative permeability of hysteresis materials μ rh Determine using the following formula: In the formula, B hm The magnetic flux density amplitude, , , All of these are constants related to electrode parameters. μ 0 is the permeability of free space. ε 0 represents the angle by which the electric field strength leads the magnetic flux density of the hysteresis material. μ rs The relative permeability of the stator core, γ 0 represents the angle at which the air gap magnetic flux density lags behind the magnetomotive force. I t This represents the stator current amplitude.

8. The rotor flux orientation control method for a hysteresis motor according to claim 4, characterized in that, Establish the stator and rotor voltage equations and flux linkage equations of the hysteresis motor in the stationary coordinate system, and calculate the values ​​in the stationary coordinate system. α , β Shaft rotor flux linkage, and based on calculations α , β The actual rotor flux linkage angle is directly calculated using the shaft rotor flux linkage, and the spatial position of the rotor flux linkage in the hysteresis motor is compared and verified.

9. The rotor flux orientation control method for a hysteresis motor according to claim 8, characterized in that, The stator and rotor voltage equations of the hysteresis motor are: In the formula, u sα , i sα They are respectively α Shaft stator voltage and current; u sβ , i sβ They are respectively β Shaft stator voltage and current; u rα , i rα They are respectively α Shaft rotor voltage and current; u rβ , i rβ They are respectively β Shaft rotor voltage and current; R s The resistance of the stator coil, R r The rotor's equivalent resistance; ψ sα , ψ sβ They are respectively α , β Shaft stator flux linkage; ψ rα , ψ rβ They are respectively α , β Rotor flux linkage; The flux linkage equation, which characterizes the mathematical relationship between stator and rotor flux linkage, inductance, and current, is as follows: In the formula, L ls Leakage inductance between stator coils; L m The mutual inductance between the stator and the rotor; L hr The mutual inductance caused by the hysteresis effect of the rotor itself using magnetic materials is determined by the permeability dynamically corresponding to the current magnetization operating point.

10. A rotor flux orientation control system for a hysteresis motor, characterized in that, A rotor flux orientation control method for a hysteresis motor according to any one of claims 1-9; the system includes: Hysteresis motor module, used to acquire real-time operating information of hysteresis motor; The flux linkage coordinate transformation module is used to determine the spatial position of the rotor flux linkage of the hysteresis motor and use it as the orientation reference of the rotating coordinate system to perform coordinate transformation between the stationary coordinate system and the rotating coordinate system, so that the current control axis and the rotor flux linkage direction are dynamically kept consistent. The outer and inner loop control modules are used to perform speed outer loop control and current inner loop control, and to obtain the current component determined by the current control axis and the control voltage component obtained by closed-loop adjustment based on the current component. An inverter drive module is used to convert at least the control voltage component into a drive signal for hysteresis motor control.

Images