High-speed magnetic levitation motor rotor vibration prevention method, system, electronic equipment and medium

Abstract

The present invention discloses a high-speed magnetic levitation motor rotor vibration prevention method, system, electronic equipment and medium. The method maintains the rotor in a suspended state, sweeps the frequency across the full motor speed range to obtain a response matrix of an excitation signal, takes the inverse matrix of the response matrix to obtain compensation matrices AVC0 and AVC2, and stores the compensation matrices in a controller and in an EEPROM. One matrix is used to reduce the magnetic bearing force, and the other matrix is used to compensate for the phase and reduce the displacement, thereby realizing dual-matrix vibration prevention control of a high-speed magnetic levitation rotor that can reduce both the magnetic bearing force and the displacement.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic levitation motor rotor vibration control, and in particular to a high-speed magnetic levitation motor rotor vibration prevention method, system, electronic equipment and medium. Background Art

[0002] A levitation motor is a motor that uses magnetic bearings to suspend the motor rotor. With the magnetic bearing support technology, the motor rotor and bearings are contactless, which has the following advantages: (1) no friction and wear, long service life; (2) easy to achieve higher speeds; (3) no need for lubrication and maintenance; (4) low heat generation and low power consumption; (5) oil-free, suitable for use in the food, pharmaceutical and fermentation industries; (6) strong environmental adaptability, able to work in vacuum and corrosive media. Given the above advantages, magnetic levitation high-speed motors have been increasingly widely used in magnetic levitation fluid machinery such as blowers, air compressors, vacuum pumps, refrigeration compressors, and ORCs.

[0003] Due to design and processing flaws, material inhomogeneity, thermal deformation, and other factors, rotor systems inevitably experience mass imbalances. This generates centrifugal forces at the same frequency as the rotor's rotational speed. This centrifugal force is proportional to the square of the rotor's speed and causes rotor vibration. In addition to centrifugal force, rotor rotation is also affected by external disturbances (such as aerodynamics), inertia, and gravity. When rotating machinery operates at high speeds, excessive vibration can severely impact the system. Therefore, rotor vibration control technology is of paramount importance for high-speed rotating machinery.

[0004] In the prior art, rotor vibration control generally adopts bearing electromagnetic force minimum control or vibration displacement minimum control. The bearing electromagnetic force minimum algorithm and the rotor displacement minimum algorithm are two completely opposite control methods, each with its own advantages and disadvantages. The bearing electromagnetic force minimum control algorithm has the problem of closed-loop system instability at low speeds. Although the rotor displacement minimum algorithm can achieve high-precision rotation of the rotor, it is easy to cause power amplifier saturation and amplify the phase difference between the rotor vibration phase and the unbalanced force under high-speed conditions. It is usually suitable for situations with lower speeds. Moreover, neither of these two algorithms solves the phase lag problem. During the speed-up process, there is a lag phase between the rotor unbalance force and the rotor's co-frequency vibration displacement as the speed increases. If this lag phase is not compensated during the imbalance suppression process, it will lead to increased unbalanced vibration and even instability. Summary of the Invention

[0005] Technical purpose: In view of the shortcomings of existing rotor vibration control methods, the present invention discloses a high-speed magnetic levitation motor rotor vibration prevention method, system, electronic equipment and medium.

[0006] Technical solution: To achieve the above technical objectives, the present invention adopts the following technical solution:

[0007] A high-speed magnetic levitation motor rotor vibration prevention method comprises the following steps:

[0008] S01, the rotor is kept in suspension state, and the frequency is swept across the full speed range of the motor to obtain the displacement signal output by the displacement sensor minus the excitation signal, and the response matrix AVC0' corresponding to the response signal at the controller input end;

[0009] S02, the rotor is kept in suspension state, and the frequency is swept across the full speed range of the motor to obtain the control signal output by the controller and the excitation signal, and the response matrix AVC2' corresponding to the response signal at the output end of the displacement sensor;

[0010] S03. Take the inverse matrix of the response matrices AVC0' and AVC2' obtained in steps S01 and S02 to obtain compensation matrices AVC0 and AVC2. The compensation matrices are stored in the controller. When performing rotor vibration control, the electrical signals at the positions where the excitation signals are applied in steps S01 and S02 are compensated by calling the compensation matrices.

[0011] Preferably, in step S01 and step S02 of the present invention, the excitation signal is a sinusoidal signal with a frequency ranging from 10 Hz to the rated speed frequency of the motor and a step size of 10 Hz or 20 Hz.

[0012] Preferably, in step S03 of the present invention, the process of compensating the electrical signal using the compensation matrix includes:

[0013] S031. Generate corresponding same-frequency sine avcSin and cosine avcCos according to the sine function corresponding to the electrical signal;

[0014] S032. Determine the rotation angle range of the rotor in the current cycle, and multiply the sine function with the corresponding sine and cosine of the same frequency, perform periodic summing, and average to obtain the real part axis_s and imaginary part axis_c of the complex representation of the electrical signal;

[0015] S033. According to the product of the compensation matrix and the real part axis_s and the imaginary part axis_c of the electrical signal, a compensation function for the electrical signal is obtained: AVCComp = (comp_s * avcSin + comp_c * avcCos), where comp_s and comp_c are the real part and imaginary part of the corresponding matrix after calculation, respectively.

[0016] Preferably, when the present invention uses the compensation matrix AVC2 to perform electrical signal compensation, the modulus value of the current compensation function is calculated. ; and compare the modulus value with the modulus value AMP_Last of the compensation function of the previous vibration control cycle. When the modulus of the magnetic bearing current is greater than 50% of the bias current or the displacement change output by the displacement sensor is less than 10% of the gap, and AMP is greater than AMP_Last, the compensation is limited. =AMP_Last.

[0017] Preferably, in steps S01 and S02 of the present invention, the real and imaginary part changes of the response signal relative to the excitation signal are obtained by expressing the electrical signal in a complex form, and a corresponding response matrix between the two is obtained.

[0018] A high-speed magnetic levitation motor rotor vibration isolation system includes a magnetic bearing, a displacement sensor, and a controller. The displacement sensor is connected to the controller, and the coil of the magnetic bearing is connected to a power amplifier. The displacement sensor obtains a rotor displacement signal. According to the high-speed magnetic levitation motor rotor vibration isolation method described above, the input and output signals of the controller are compensated to control the vibration of the rotor.

[0019] An electronic device comprises: a memory for storing a computer program; and a processor for executing the computer program so that the device executes the above-mentioned high-speed magnetic levitation motor rotor vibration isolation method.

[0020] A computer-readable storage medium stores a computer program. When the computer program is executed, a device executing the computer program implements the above-mentioned high-speed magnetic levitation motor rotor vibration prevention method.

[0021] Beneficial effects: The high-speed magnetic levitation motor rotor vibration isolation method, system, electronic equipment, and medium disclosed in the present invention have the following beneficial effects:

[0022] 1. The present invention combines the advantages of minimum control of bearing electromagnetic force and minimum control of rotor displacement, and at the same time adds a phase compensation imbalance suppression method. Two compensation matrices are determined by a frequency sweep method and stored in the controller's storage medium EEPROM. One matrix is used to reduce the magnetic bearing force, and the other matrix is used to compensate for the phase to reduce the displacement. This realizes a high-speed magnetic levitation rotor dual-matrix vibration isolation control that can reduce both the magnetic bearing force and the displacement.

[0023] 2. The present invention obtains the compensation matrix through the pre-sweep method and stores it in EEPROM. In actual control, a lot of complex calculations are omitted. The corresponding compensation matrix can be directly called for calculation according to the operating conditions of the motor, which reduces the computing power requirements of the controller and is easy to implement in engineering. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] 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.

[0025] Figure 1 Schematic diagram of the structure of a single-degree-of-freedom magnetic bearing system;

[0026] Figure 2 Schematic diagram of applying excitation when obtaining the response matrix AVC0' of the present invention;

[0027] Figure 3 Schematic diagram of applying excitation when obtaining the response matrix AVC2' of the present invention;

[0028] Figure 4 This is a schematic diagram of the present invention using a compensation matrix to perform rotor vibration control;

[0029] Figure 5 Schematic diagram of 5-degree-of-freedom magnetic bearing of the present invention;

[0030] Among them, 1-electromagnet, 2-rotor, 3-displacement sensor, 4-controller, 5-power amplifier. DETAILED DESCRIPTION

[0031] 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.

[0032] like Figure 1-Figure 5 As shown, the present invention discloses a high-speed magnetic levitation motor rotor vibration prevention method, comprising the steps of:

[0033] S01, the rotor is kept in suspension state, and the frequency is swept across the full speed range of the motor to obtain the displacement signal output by the displacement sensor minus the excitation signal, and the response matrix AVC0' corresponding to the response signal at the controller input end;

[0034] like Figure 2 As shown in the figure, a represents the reference displacement signal, represented by Ref, which represents the suspension center of the rotor; g represents the output of the displacement sensor, represented by Vposition, q0 is the excitation signal 0, represented by Excitation0; b is the input of the controller, represented by En, and the input signal En=Ref-Vposition-Excitation0.

[0035] Point c represents the output of the controller, which is also the input of the power amplifier, expressed in voltage. Point e represents the output voltage of the power amplifier, and point f is the magnetic bearing current. Subtracting the excitation signal 0 from point q0 in the figure will result in a response at point b of the controller. Based on the response signal at the corresponding excitation signal frequency and the relationship between the response signal and the original excitation signal, the response matrix AVC0' of the signal change can be obtained.

[0036] S02, the rotor is kept in suspension state, and the frequency is swept across the full speed range of the motor to obtain the control signal output by the controller and the excitation signal, and the response matrix AVC2' corresponding to the response signal at the output end of the displacement sensor;

[0037] like Figure 3 As shown in the figure, a represents the reference displacement signal, represented by Ref, corresponding to the suspension center of the rotor; g represents the output of the displacement sensor, represented by Vposition, q2 is the excitation signal 2, represented by Excitation2; b is the input of the controller, represented by En. Since the electrical signals are all sinusoidal signals, they can be directly superimposed on each other, so the controller input signal En=Ref-Vposition.

[0038] c represents the output of the controller, represented by U4; h represents the input of the power amplifier, which is equal to Excitation2 + U4; e represents the output voltage of the power amplifier (abbreviated as power amplifier); f is the magnetic bearing current.

[0039] When excitation signal 2 is applied at q2, the input of the power amplifier changes, which is ultimately reflected in the output change of the displacement sensor, that is, the change of Vposition at g. The response matrix AVC2' is obtained based on the change of the response signal generated by excitation signal 2 at g.

[0040] In steps S01 and S02, the present invention obtains the corresponding response matrix between the real and imaginary parts of the response signal relative to the excitation signal by using a complex representation of the electrical signal. The excitation signal is a sinusoidal signal with a frequency ranging from 10 Hz to the rated speed of the motor, with a step size of 10 Hz or 20 Hz. The step size can be selected based on the controller EEPROM memory and the required rotor vibration control accuracy. By changing the corresponding excitation frequency, the corresponding compensation matrix is obtained at different motor speeds, thereby enabling control and compensation of rotor vibration under different operating conditions during the operation of the magnetic levitation motor.

[0041] S03. Take the inverse matrix of the response matrices AVC0' and AVC2' obtained in steps S01 and S02 to obtain compensation matrices AVC0 and AVC2, and store the compensation matrices in the controller EEPROM. When performing rotor vibration control, the electrical signals at the positions where the excitation signals are applied in steps S01 and S02 are compensated by calling the compensation matrices.

[0042] like Figure 3 As shown, when using the compensation matrix for vibration control, when using AVC0, the signal is extracted at the controller input and inserted at Ref-Vposition; when using AVC2, the signal is extracted at Ref-Vposition and inserted at the controller output.

[0043] In step S03 of the present invention, the process of compensating the electrical signal using the compensation matrix includes:

[0044] S031. Generate corresponding same-frequency sine avcSin and cosine avcCos according to the sine function corresponding to the electrical signal;

[0045] S032. Determine the rotation angle range of the rotor in the current cycle, and multiply the sine function with the corresponding sine and cosine of the same frequency, perform periodic summing, and average to obtain the real part axis_s and imaginary part axis_c of the complex representation of the electrical signal;

[0046] Assuming a sinusoidal signal , the amplitude is A, and the initial phase angle is ; Generate a sine wave with the same frequency as the sine signal and cosine ;

[0047] Multiplying the sine signal with its sine and cosine of the same frequency yields:

[0048] ;

[0049] ;

[0050] After low-pass filtering or periodic summation of the above formula, and then taking the average value, the real part is ; The imaginary part is ;

[0051] The amplitude ;

[0052] Initial phase .

[0053] For each control cycle of the controller, it is necessary to calculate the rotor angle change within one control cycle based on the control cycle Ts and the current frequency f. ; and according to the rotor angle position of the previous cycle , get the rotor angle of the current control cycle = + .

[0054] At this time, the same frequency sine avcSin= and the same frequency cosine avcCos= ), calculate the rotor angle within a control cycle The corresponding axis_s and axis_c.

[0055] S033. Based on the product of the compensation matrix and the real part axis_s and the imaginary part axis_c of the electrical signal, the compensation function for the electrical signal is obtained: AVCComp = (comp_s * avcSin + comp_c * avcCos), where comp_s and comp_c are the real and imaginary parts of the corresponding matrix after calculation, respectively; accordingly, the compensation function AVCComp0 corresponding to the compensation matrix AVC0 and the compensation function AVCComp2 corresponding to the compensation matrix AVC2 are obtained.

[0056] like Figure 5 As shown in the figure, the conventional rotor has five degrees of freedom of movement and one degree of freedom of rotation along the circumference of the rotor. The vibration control of the rotor is achieved by changing the five degrees of freedom of movement of the rotor through magnetic bearings. In the figure, X1 and Y1 are upper radial, X2 and Y2 are lower radial, and Z is axial, denoted as axi.

[0057] In the present invention, the z-axis is taken as an example to illustrate the process of establishing the compensation function through the compensation matrix of the present invention.

[0058] Compensation Matrix As the transfer function between signal input and output; axial Z direction ; where a11 is the real part of the transfer function, a21 is the imaginary part of the transfer function; axi_axis_s is the real part of the input signal (displacement), axi_axis_c is the imaginary part of the input signal (displacement); axi_comp_s is the real part of the compensation function, axi_comp_c is the imaginary part of the compensation function.

[0059] In addition, when the compensation matrix AVC2 is used for phase compensation in the present invention, AVCComp2 needs to be limited to avoid excessive reduction of displacement vibration, which leads to saturation of the power amplifier current and increases unnecessary losses; the modulus of the current compensation function is calculated; and the modulus is compared with the modulus AMP_Last of the compensation function of the previous vibration control cycle. When the modulus of the magnetic bearing current is greater than 50% of the bias current or the displacement change output by the displacement sensor is less than 10% of the gap, and AMP is greater than AMP_Last, the compensation is limited. At this time, limit = AMP_Last; as shown in FIG. Figure 1 As shown, the controller 4 generates a control signal, and the power amplifier 5 generates a corresponding control current so that the electromagnet 1 can generate magnetic force to control the stable suspension of the rotor 2; the bias current It is the basic current that continuously exists in the electromagnetic bearing coil, which is used to maintain the stable suspension of the rotor in the absence of external interference or control signals. When performing vibration control, it is necessary to increase or decrease the bias current of the coil on the corresponding electromagnet 1 accordingly; the gap is the movable stroke of the rotor. When the rotor floats at the center, the gap can be obtained by multiplying the single-side distance from the protective bearing by 2.

[0060] Preferably, in steps S01 and S02 of the present invention, the real and imaginary part changes of the response signal relative to the excitation signal are obtained by expressing the electrical signal in a complex form, and a corresponding response matrix between the two is obtained.

[0061] A high-speed magnetic levitation motor rotor vibration isolation system includes a magnetic bearing, a displacement sensor, and a controller. The rotor displacement sensor is connected to the controller, and the coil of the magnetic bearing is connected to a power amplifier. The rotor displacement signal is obtained by the displacement sensor. The input and output signals of the controller are compensated according to the high-speed magnetic levitation motor rotor vibration isolation method described above, thereby controlling the vibration of the rotor.

[0062] An electronic device comprises: a memory for storing matrix data; and a processor for executing the computer program so that the device executes the above-mentioned high-speed magnetic levitation motor rotor vibration isolation method.

[0063] A computer-readable storage medium stores matrix data. When the computer program is executed, the device executing the computer program implements the above-mentioned high-speed magnetic levitation motor rotor vibration isolation method.

[0064] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A high-speed magnetic levitation motor rotor vibration isolation method, characterized in that: Including steps: S01, the rotor is kept in suspension state, and the frequency is swept across the full speed range of the motor to obtain the displacement signal output by the displacement sensor minus the excitation signal, and the response matrix AVC0' corresponding to the response signal at the controller input end; S02, the rotor is kept in suspension state, and the frequency is swept across the full speed range of the motor to obtain the control signal output by the controller and the excitation signal, and the response matrix AVC2' corresponding to the response signal at the output end of the displacement sensor; S03, taking the inverse matrix of the response matrices AVC0' and AVC2' obtained in step S01 and step S02 to obtain compensation matrices AVC0 and AVC2, storing the compensation matrices in the controller, and compensating the electrical signals at the positions where the excitation signals are applied in steps S01 and S02 by calling the compensation matrices when performing rotor vibration control; In step S03, the process of compensating the electrical signal using the compensation matrix includes: S031. Generate corresponding same-frequency sine avcSin and cosine avcCos according to the sine function corresponding to the electrical signal; S032. Determine the rotation angle range of the rotor in the current cycle, and multiply the sine function with the corresponding sine and cosine of the same frequency, perform periodic summing, and average to obtain the real part axis_s and imaginary part axis_c of the complex representation of the electrical signal; S033. According to the product of the compensation matrix and the real part axis_s and the imaginary part axis_c of the electrical signal, a compensation function for the electrical signal is obtained: AVCComp = (comp_s * avcSin + comp_c * avcCos), where comp_s and comp_c are the real part and imaginary part of the corresponding matrix after calculation, respectively.

2. The high-speed magnetic levitation motor rotor vibration isolation method according to claim 1, characterized in that: In step S01 and step S02 , the excitation signal is a sinusoidal signal with a frequency ranging from 10 Hz to the rated speed frequency of the motor and a step length of 10 Hz or 20 Hz.

3. The high-speed magnetic levitation motor rotor vibration isolation method according to claim 1, characterized in that: When using the compensation matrix AVC2 for electrical signal compensation, calculate the modulus of the current compensation function ; The modulus value is compared with the modulus value AMP_Last of the compensation function of the previous vibration control cycle. When the modulus of the magnetic bearing current is greater than 50% of the bias current or the displacement change output by the displacement sensor is less than 10% of the gap, and AMP is greater than AMP_Last, the compensation is limited. =AMP_Last.

4. The high-speed magnetic levitation motor rotor vibration isolation method according to claim 1, characterized in that: In steps S01 and S02 , the electrical signal is expressed in a complex number form to obtain the real and imaginary part changes of the response signal relative to the excitation signal, and a corresponding response matrix between the two is obtained.

5. A high-speed magnetic levitation motor rotor vibration isolation system, characterized in that: The invention comprises a magnetic bearing, a displacement sensor and a controller, wherein the displacement sensor is connected to the controller, and the coil of the magnetic bearing is connected to a power amplifier. The displacement signal of the rotor is obtained by the displacement sensor. According to the high-speed magnetic levitation motor rotor vibration isolation method according to any one of claims 1 to 4, the input and output signals of the controller are compensated to control the vibration of the rotor.

6. An electronic device, characterized in that: include: memory for storing computer programs; A processor is used to execute the computer program so that the device performs the high-speed magnetic levitation motor rotor vibration isolation method according to any one of claims 1 to 4.

7. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program. When the computer program is executed, the device executing the computer program implements the high-speed magnetic levitation motor rotor vibration isolation method according to any one of claims 1 to 4.

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