A motor magnetic bearing assembly calibration method, system, electronic equipment and medium

Abstract

The present invention discloses a method for assembling and calibrating a magnetic bearing of a motor, a system, an electronic device and a medium. When calibrating the magnetic bearing, a correlation model between a control current and a three-phase current of the motor in a rotor rotating coordinate system is first established; the rotation angle of the rotor is adjusted by changing the control current, and the motor adjusts the three-phase current accordingly based on the control current to perform a rotation operation on the rotor; with the initial position in the rotor rotating coordinate system being the 0-degree position, the rotor is controlled to rotate one circle at 45-degree intervals in sequence, and at the 0-degree position and after each rotation, the rotor is controlled to suspend to a balanced position by a magnetic bearing controller, and the magnetic bearing is calibrated at each angle. The present invention can simplify the control strategy of the motor for the rotation of the rotor and can accurately control the rotor position, thereby reducing manual participation, saving operation time, and greatly improving the efficiency and accuracy of multi-angle calibration.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic levitation motors, and in particular to a method, system, electronic equipment and medium for assembling and calibrating a magnetic bearing of a motor. Background Art

[0002] Magnetic bearings primarily consist of electromagnets, displacement sensors, controllers, and power amplifiers. Magnetic bearings use electromagnets mounted on the stator to generate electromagnetic force on the rotor, enabling stable levitation and rotation without contact with the bearings. To ensure stable levitation during high-speed rotor rotation, the assembly process of the magnetic bearings and sensors—that is, the centrality of the magnetic bearing system—must be tested. The magnetic bearings primarily provide electromagnetic force to cause the rotor to move in a circular motion against the protective bearings. Sensors detect rotor displacement signals, and the controller processes these signals to obtain calibration information and generate control signals. The power amplifier converts these control signals into radial and axial control currents, which drive the electromagnets to generate magnetic force, levitating the rotor to its equilibrium position. This entire process is called magnetic bearing calibration. By measuring and comparing the offset, gain, and levitation current values ​​of the calibration results at multiple angles, the difference and absolute value at each angle are ensured to be within the rated range, thereby verifying the concentricity of the assembly process—that is, the concentricity of the magnetic bearing system. In the existing technology, judgment is generally made based on the results of multiple angle calibration. Multi-angle calibration requires the experimenter to remove the cabinet door, operate the rotor to rotate 45 degrees, calibrate once, and then operate the rotor to rotate 45 degrees again, repeat multiple times and record the results. Under this operation method, the debugger can only roughly operate the rotor to rotate 45 degrees by feel, and the measurement results are not very accurate. The process of removing the cabinet door and manual operation leads to low debugging efficiency. Moreover, for models such as vacuum pumps and refrigeration compressors, the rotor cannot be touched by simply removing the cabinet door. The pipes must also be disassembled, which brings great inconvenience to debugging and maintenance. Summary of the Invention

[0003] Technical purpose: In view of the shortcomings of the existing magnetic bearing calibration of magnetic levitation motors, the present invention discloses a motor magnetic bearing assembly calibration method, system, electronic equipment and medium.

[0004] Technical solution: To achieve the above technical objectives, the present invention adopts the following technical solution:

[0005] A method for assembling and calibrating a motor magnetic bearing comprises the following steps:

[0006] S01. Establish a correlation model between the control current and the three-phase current of the motor in the rotor rotating coordinate system;

[0007] S02. The rotation angle of the rotor is adjusted by changing the control current. The motor adjusts the three-phase current accordingly according to the control current to perform the rotation operation of the rotor.

[0008] S03. With the initial position of the rotor in the rotating coordinate system as the 0-degree position, the rotor is controlled to rotate one circle at 45-degree intervals in sequence. At the 0-degree position and after each rotation, the rotor is controlled to suspend to the equilibrium position through the magnetic bearing controller. The magnetic bearing is calibrated at each angle to obtain the bias value, gain value, and suspension current of the magnetic bearing.

[0009] Preferably, the process of establishing the association model in step S01 of the present invention includes: converting the natural coordinate system of the three-phase winding current of the motor into the stationary coordinate system of the two-phase orthogonal symmetrical winding, and then transforming the stationary coordinate system of the two-phase orthogonal symmetrical winding into the rotor rotating coordinate system, and establishing the association model between the control current and the three-phase current of the motor according to the coordinate transformation formula of each coordinate system.

[0010] Preferably, the transformation formula of the natural coordinate system to the stationary coordinate system of the present invention is: The transformation formula from the stationary coordinate system to the rotor rotating coordinate system is: where i α 、i β They represent the currents of the α and β axes in the stationary coordinate system, i A 、i B 、i C Respectively represent the current of phase A, B, and C in the natural coordinate system, i d 、i q They represent the currents of the d-axis and q-axis in the rotating coordinate system, and θ represents the angle of rotation of the rotor.

[0011] Preferably, in step S03 of the present invention, when calibrating the magnetic bearing, the rotor is first kept in a stationary state at a corresponding angle by controlling the current, and then the magnetic bearing controller controls the electromagnet to generate electromagnetic force, driving the rotor to perform circular motion along the inner circumference of the protective bearing, and the displacement sensor provided in the motor detects the displacement signal of the rotor during the circular motion to obtain the suspended position of the rotor, and the electromagnet is used to keep the rotor suspended to the equilibrium position to obtain the bias value, gain value and suspension current of the magnetic bearing at this time.

[0012] The present invention provides a motor magnetic bearing assembly calibration system, which uses the above-mentioned calibration method and includes a controller for controlling the current of the motor's three-phase winding. The controller is electrically connected to the motor's displacement sensor and magnetic bearing controller. The controller controls the motor rotor to rotate according to the calibration method to automatically calibrate the magnetic bearing.

[0013] The present invention discloses an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the above-mentioned method for calibrating the assembly of a motor magnetic bearing is implemented.

[0014] A computer-readable storage medium stores computer-executable instructions, wherein the computer-executable instructions are used to execute the above-mentioned motor magnetic bearing assembly calibration method.

[0015] Beneficial effects: Compared with the prior art method of manually operating the rotor to calibrate multiple angles, the motor magnetic bearing assembly calibration method, system, electronic equipment and medium disclosed in the present invention simplifies the control strategy and can accurately control the rotor position, reducing manual participation, saving operation time, greatly improving the efficiency and accuracy of multi-angle calibration, laying the foundation for the stability of the subsequent magnetic levitation system at high speed, and having wide applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for describing the embodiments or the prior art.

[0017] Figure 1 Flowchart for calibration of existing magnetic bearings;

[0018] Figure 2 Flowchart for assembling and calibrating the magnetic bearing of the present invention

[0019] Figure 3 This is a diagram showing the circular motion state of the rotor in the protective bearing when the magnetic bearing is calibrated in the present invention;

[0020] Figure 4 This is a schematic diagram of rotor rotation calibration during the magnetic bearing calibration process of the present invention. DETAILED DESCRIPTION

[0021] Reference will now be made in detail to the embodiments of the present disclosure, one or more examples of which are set forth herein below. Each embodiment and example is provided by way of explanation of the apparatus, composition, and materials of the present disclosure, and is not intended to be limiting. On the contrary, the following description provides a convenient illustration of exemplary embodiments for implementing the present disclosure. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made within the teachings of the present disclosure without departing from the scope or spirit of the present disclosure.

[0022] like Figures 1-4 As shown, the present invention discloses a method for assembling and calibrating a motor magnetic bearing, comprising the steps of:

[0023] S01. Establish a correlation model between the control current and the three-phase current of the motor in the rotor rotating coordinate system;

[0024] The process of establishing the association model in the present invention includes: converting the natural coordinate system of the motor three-phase winding current into the stationary coordinate system of the two-phase orthogonal symmetrical winding, then transforming the stationary coordinate system of the two-phase orthogonal symmetrical winding into the rotor rotating coordinate system, and establishing the association model between the control current and the motor three-phase current according to the coordinate transformation formula of each coordinate system.

[0025] The transformation formula of the natural coordinate system of the present invention into the stationary coordinate system is: The transformation formula from the stationary coordinate system to the rotor rotating coordinate system is: where i α 、i β They represent the currents of the α and β axes in the stationary coordinate system, i A 、i B 、i C Respectively represent the current of phase A, B, and C in the natural coordinate system, i d 、i q They represent the currents of the d-axis and q-axis in the rotating coordinate system, and θ represents the angle of rotation of the rotor.

[0026] S02. The rotation angle of the rotor is adjusted by changing the control current. The motor adjusts the three-phase current accordingly according to the control current and performs the rotation operation on the rotor. After obtaining the transformation formula of the associated model, the control current can be adjusted by controlling the i d 、i q The angle θ realizes the static positioning of the rotor at any angle in the circumferential direction, thereby meeting the positioning requirements of the rotor rotation direction during the magnetic bearing calibration process.

[0027] S03, such as Figure 4 As shown, the present invention takes the initial position of the rotor in the rotating coordinate system as the 0 degree position, and sequentially controls the rotor to rotate one circle at 45° intervals, for a total of 8 static angle calibration positions. At the 0° position and after each rotation, the rotor is controlled to suspend to the equilibrium position through the magnetic bearing controller, and the magnetic bearing is calibrated at each angle to obtain the bias value, gain value and suspension current of the magnetic bearing.

[0028] When calibrating the magnetic bearing, the rotor is first kept in a stationary state at the corresponding angle by controlling the current, and then the magnetic bearing controller controls the electromagnet to generate electromagnetic force, driving the rotor to perform circular motion along the inner circumference of the protective bearing. When the rotor moves close to the inner circumference of the protective bearing, a gap will be formed between the other parts and the protective bearing. The displacement sensor set in the motor detects the rotor to detect the gap change, obtains the displacement signal of the rotor during the circular motion, obtains the suspension position of the rotor, and uses the electromagnet to keep the rotor suspended to the equilibrium position, and obtains the bias value, gain value and suspension current of the magnetic bearing at this time. The above process is repeated in sequence to obtain the magnetic bearing calibration information corresponding to each angle of the rotor. The center degree of the magnetic bearing installation is analyzed through this calibration information to determine whether the magnetic bearing assembly meets the requirements.

[0029] The magnetic bearing calibration method of the present invention does not require disassembly of equipment structures such as cabinet door panels, pipes, etc., and can directly use the three-phase winding of the motor to control the corresponding angle of rotation of the rotor. The rotation accuracy is high, the accuracy of the calibration data is improved, and the assembly effect of the magnetic bearing can be improved; the calibration system, electronic equipment and computer medium based on the calibration method of the present invention, without departing from the design concept of the present invention, belong to the protection scope of the present invention. During the actual test process, the calibration process of the present invention can be controlled within 10 minutes, and the entire calibration process is automatically completed. Compared with the calibration process of up to 30 minutes in the prior art, the assembly detection efficiency can be effectively improved.

Claims

1. A method for assembling and calibrating a motor magnetic bearing, characterized in that: Including steps: S01. Establish a correlation model between the control current and the three-phase current of the motor in the rotor rotating coordinate system; S02. The rotation angle of the rotor is adjusted by changing the control current. The motor adjusts the three-phase current accordingly according to the control current to perform the rotation operation of the rotor. S03, with the initial position of the rotor in the rotating coordinate system as the 0 degree position, sequentially controlling the rotor to rotate one circle at 45 degree intervals, and controlling the rotor to levitate to the equilibrium position at the 0 degree position and after each rotation through the magnetic bearing controller, calibrating the magnetic bearing at each angle, and obtaining the bias value, gain value, and levitation current of the magnetic bearing; The process of establishing the association model in step S01 includes: converting the natural coordinate system of the motor three-phase winding current into the stationary coordinate system of the two-phase orthogonal symmetrical winding, then transforming the stationary coordinate system of the two-phase orthogonal symmetrical winding into the rotor rotating coordinate system, and establishing the association model between the control current and the motor three-phase current according to the coordinate transformation formula of each coordinate system; The transformation formula of the natural coordinate system into the stationary coordinate system is: The transformation formula from the stationary coordinate system to the rotor rotating coordinate system is: where i α 、i β They represent the currents of the α and β axes in the stationary coordinate system, i A 、i B 、i C Respectively represent the current of phase A, B, and C in the natural coordinate system, i d 、i q They represent the currents of the d-axis and q-axis in the rotating coordinate system, and θ represents the angle of rotor rotation; In step S03, when calibrating the magnetic bearing, the rotor is first kept in a stationary state at a corresponding angle by controlling the current, and then the magnetic bearing controller controls the electromagnet to generate electromagnetic force, driving the rotor to perform circular motion along the inner circumference of the protective bearing. The displacement sensor set in the motor detects the displacement signal of the rotor during the circular motion, obtains the suspension position of the rotor, and uses the electromagnet to keep the rotor suspended to the equilibrium position, and obtains the bias value, gain value and suspension current of the magnetic bearing at this time.

2. A motor magnetic bearing assembly calibration system, using the calibration method according to claim 1, characterized in that: The invention comprises a controller for controlling the current of the three-phase winding of the motor. The controller is electrically connected to the displacement sensor and the magnetic bearing controller of the motor. The controller controls the rotation of the motor rotor according to the calibration method to automatically calibrate the magnetic bearing.

3. An electronic device, characterized in that: The method comprises a memory, a processor and a computer program stored in the memory and executable on the processor. When the processor executes the program, the method for calibrating the assembly of a motor magnetic bearing as claimed in claim 1 is implemented.

4. A computer-readable storage medium, characterized in that Computer-executable instructions are stored, and the computer-executable instructions are used to execute the motor magnetic bearing assembly calibration method according to claim 1.

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