Motor magnetic bearing assembly calibration method and system, electronic equipment and medium

Abstract

The invention discloses a motor magnetic bearing assembly calibration method and system, electronic equipment and a medium, and the method comprises the steps: building a correlation model between a control current and a motor three-phase current under a rotor rotating coordinate system during the calibration of a magnetic bearing; the rotation angle of the rotor is adjusted by changing the control current, the motor correspondingly adjusts the three-phase current according to the control current, and rotation operation on the rotor is executed; taking the initial position of the rotor in a rotating coordinate system as a 0-degree position, sequentially controlling the rotor to rotate for a circle according to 45-degree intervals, controlling the rotor to suspend to a balance position through a magnetic bearing controller at the 0-degree position and after each rotation, and calibrating the magnetic bearing at each angle, according to the invention, the control strategy of the motor to the rotation of the rotor can be simplified, the position of the rotor can be accurately controlled, manual participation is reduced, the operation time is saved, and the efficiency and accuracy of multi-angle calibration are greatly improved.

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] The magnetic bearing is mainly composed of electromagnets, displacement sensors, controllers and power amplifiers. The magnetic bearing uses the electromagnets installed on the stator to generate electromagnetic force on the rotor, so that the rotor can be stably suspended and rotated without contact with the bearing. In order to ensure that the rotor remains stably suspended when rotating at high speed, it is necessary to first detect the assembly process of the magnetic bearing and the sensor, that is, the center of the magnetic bearing system. The magnetic bearing mainly provides electromagnetic force to make the rotor move in a circular motion against the protective bearing. The sensor detects the displacement signal of the rotor. The controller processes the displacement signal to obtain calibration information and generates a control signal. The power amplifier converts the control signal into radial and axial control currents, thereby driving the electromagnet to generate magnetic force and suspend the rotor to a balanced position. The whole process is called the calibration of the magnetic bearing. By detecting and comparing the offset value, gain value and suspension current of the calibration results at multiple angles, it is ensured that the difference and absolute value of each angle are within the rated range to detect the assembly process, that is, the concentricity of the magnetic bearing system. In the prior art, judgment is generally made through calibration results at multiple angles. Multi-angle calibration requires the experimenter to disassemble the cabinet door, operate the rotor to rotate 45 degrees, calibrate once, and then operate the rotor to rotate 45 degrees, repeat multiple times and record. In this operation mode, the debugging personnel can only roughly operate the rotor to rotate 45 degrees by feel, and the measurement results are not accurate. The process of disassembling the cabinet door and manual operation leads to low debugging efficiency. In addition, the rotor of vacuum pumps, refrigeration compressors and other models cannot be touched by only disassembling the cabinet door, and the pipeline needs to be disassembled, which brings more 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. Establishing a correlation model between the control current and the three-phase current of the motor in the rotor rotating coordinate system;

[0007] S02, adjusting the rotation angle of the rotor by changing the control current, and the motor correspondingly adjusts the three currents 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, and at the 0 degree 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.

[0009] Preferably, the process of establishing the association model in step S01 of 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, 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 motor three-phase current 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 current of the d-axis and q-axis in the rotating coordinate system respectively, 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 signal of the rotor during the circular motion is detected by the displacement sensor provided in the motor to obtain the suspended position of the rotor, and the rotor is kept suspended to a balanced position by the electromagnet 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 motor magnetic bearing assembly calibration method 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 device and medium disclosed in the present invention simplifies the control strategy and can accurately control the rotor position, reduces manual participation, saves operation time, greatly improves the efficiency and accuracy of multi-angle calibration, lays a foundation for the stability of the subsequent magnetic levitation system at high speed, and has 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 drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

[0017] Figure 1 Provide a flow chart for calibrating existing magnetic bearings;

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

[0019] Figure 3 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 It 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 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, rather than limitation. On the contrary, the following description provides a convenient illustration of an exemplary embodiment for implementing the present disclosure. In fact, it will be clear to those skilled in the art that various modifications and variations may be made in the teachings of the present disclosure without departing from the scope or spirit of the present disclosure.

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

[0023] S01. Establishing 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, 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 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 current of the d-axis and q-axis in the rotating coordinate system respectively, 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 currents accordingly according to the control current to perform the rotation operation on the rotor. After obtaining the transformation formula of the associated model, the control current can be adjusted by controlling 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 degree intervals, for a total of 8 static angle calibration positions. At the 0 degree 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 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. When the rotor moves close to the inner circumference of the protective bearing, a gap is formed between the other parts and the protective bearing. The rotor is detected by a displacement sensor arranged in the motor to detect the gap change, obtain the displacement signal of the rotor during the circular motion, obtain the suspension position of the rotor, and keep the rotor suspended to the equilibrium position by an electromagnet, obtain the offset value, gain value and suspension current of the magnetic bearing at this time, repeat the above process in sequence, obtain the magnetic bearing calibration information corresponding to each angle of the rotor, analyze the center degree of the magnetic bearing installation through these calibration information, and judge 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. In 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: Includes steps: S01. Establishing a correlation model between the control current and the three-phase current of the motor in the rotor rotating coordinate system; S02, adjusting the rotation angle of the rotor by changing the control current, and the motor correspondingly adjusts the three currents 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, 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 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.

2. A motor magnetic bearing assembly calibration method according to claim 1, characterized in that: 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, 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 motor three-phase current according to the coordinate transformation formula of each coordinate system.

3. A motor magnetic bearing assembly calibration method according to claim 2, characterized in that: The transformation formula of the natural coordinate system to 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 current of the d-axis and q-axis in the rotating coordinate system respectively, and θ represents the angle of rotation of the rotor.

4. A motor magnetic bearing assembly calibration method according to claim 1, characterized in that: 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, 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 a balanced position to obtain the bias value, gain value and suspension current of the magnetic bearing at this time.

5. A motor magnetic bearing assembly calibration system, using the calibration method according to any one of claims 1 to 4, 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 with 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.

6. An electronic device, characterized in that: It includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, a motor magnetic bearing assembly calibration method as described in any one of claims 1 to 4 is implemented.

7. A computer-readable storage medium, characterized in that: Computer executable instructions are stored, and the computer executable instructions are used to execute a motor magnetic bearing assembly calibration method as described in any one of claims 1-4.

Images