High-speed magnetic suspension motor rotor anti-vibration method and system, electronic equipment and medium

Abstract

The invention discloses a high-speed magnetic suspension motor rotor anti-vibration method and system, electronic equipment and a medium, and the method comprises the steps: enabling a rotor to keep a suspension state, obtaining a response matrix of an excitation signal through frequency sweeping in a full rotation speed range of a motor, carrying out the inversion of the response matrix, obtaining compensation matrixes AVC0 and AVC2, enabling the compensation matrixes to be stored in a controller, storing the compensation matrixes into an EEPROM, and carrying out the control of the motor. One matrix is used for reducing the magnetic bearing force, and the other matrix is used for compensating the phase to reduce the displacement, so that the double-matrix anti-vibration control of the high-speed magnetic suspension rotor, which can reduce both the magnetic bearing force and the displacement, is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic levitation motor rotor vibration control, and specifically relates to a vibration prevention method, system, electronic device and medium for a high-speed magnetic levitation motor rotor. Background Technique

[0002] A magnetic levitation motor refers to a motor that suspends the motor rotor using a magnetic levitation bearing. After adopting the magnetic levitation bearing support technology, there is no contact between the rotor and the bearing of the motor, and it 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) small heat generation and low power consumption; (5) oil-free, can be used in the food, pharmaceutical and fermentation industries; (6) strong environmental adaptability, can work in vacuum and corrosive media. In view of the above advantages, magnetic levitation high-speed motors have been increasingly widely used in magnetic levitation fluid machinery fields such as blowers, air compressors, vacuum pumps, refrigeration compressors, and ORCs.

[0003] Due to reasons such as design and processing defects, non-uniform material, and thermal deformation, the rotor system inevitably has mass imbalance, which will generate a centrifugal force with the same frequency as the rotational speed. This centrifugal force is proportional to the square of the rotor speed and causes the rotor to vibrate. During the rotation of the rotor, in addition to the centrifugal force, there are also external force disturbances (such as pneumatic), inertial forces, gravity, etc. When the rotating machinery operates at high speeds, excessive vibration will have a serious impact on the system. Therefore, the rotor vibration control technology is of great significance for high-speed rotating machinery.

[0004] In the prior art, for the vibration control of the rotor, generally the minimum bearing electromagnetic force control or the minimum vibration displacement control is adopted. The bearing electromagnetic force minimum algorithm and the rotor displacement minimum algorithm are two completely opposite control methods, each having its own advantages and defects. The bearing electromagnetic force minimum control algorithm has the problem of instability of the closed-loop system at low speeds. Although the rotor displacement minimum algorithm can achieve high-precision rotation of the rotor, it is prone to amplifier saturation and amplify the phase difference between the rotor vibration phase and the unbalanced force phase under high-speed operating conditions, and is usually applicable to situations with relatively low speeds. Moreover, neither of these two algorithms solves the phase lag problem. During the speed-up process, there is a lag phase that increases with the rotational speed between the rotor unbalanced force and the rotor synchronous vibration displacement. If the lag phase is not compensated during the unbalance suppression process, it will lead to an increase in unbalanced vibration and even instability problems. Summary of the Invention

[0005] Technical Objective: Aiming at the deficiencies of the existing rotor vibration control methods, the present invention discloses a vibration prevention method, system, electronic device and medium for a high-speed magnetic levitation motor rotor.

[0006] Technical Solution: To achieve the above technical objective, the present invention adopts the following technical solutions: A method for preventing vibration of a high-speed maglev motor rotor, comprising the steps: S01. The rotor maintains a suspended state. In the full speed range of the motor, a frequency sweep is performed to obtain the response matrix AVC0' of the response signal corresponding to the input end of the controller after subtracting the excitation signal from the displacement signal output by the displacement sensor. S02. The rotor maintains a suspended state. In the full speed range of the motor, a frequency sweep is performed to obtain the response matrix AVC2' of the response signal corresponding to the output end of the displacement sensor after adding the excitation signal to the control signal output by the controller. S03. Take the inverse matrices of the response matrices AVC0' and AVC2' obtained in step S01 and step S02 to obtain the compensation matrices AVC0 and AVC2, and store the compensation matrices in the controller. When performing rotor vibration control, compensate the electrical signals at the positions where the excitation signals are applied in step S01 and step S02 by retrieving the compensation matrices.

[0007] Preferably, in step S01 and step S02 of the present invention, the excitation signal is a sine 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.

[0008] Preferably, in step S03 of the present invention, the process of compensating the electrical signal using the compensation matrix includes: S031. Generate corresponding in-phase sine avcSin and cosine avcCos according to the sine function corresponding to the electrical signal. S032. Confirm the rotation angle range of the rotor within the current period, and multiply the sine function by the corresponding in-phase sine and in-phase cosine respectively, perform periodic summation and averaging, and 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 imaginary part axis_c of the electrical signal, obtain the compensation function for the electrical signal: 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.

[0009] Preferably, when using the compensation matrix AVC2 to compensate the electrical signal in the present invention, calculate the modulus value of the current compensation function ; and compare the modulus value with the modulus value AMP_Last of the compensation function in the previous vibration control period. When the modulus of the magnetic bearing current is greater than 50% of the bias current or the displacement change amount output by the displacement sensor is less than 10% of the clearance, and AMP is greater than AMP_Last, then limit the compensation, limit = AMP_Last.

[0010] Preferably, in steps S01 and S02 of the present invention, by using the form of representing the electrical signal with complex numbers, the real and imaginary part changes of the response signal relative to the excitation signal are obtained, and the corresponding response matrix between the two is obtained.

[0011] A vibration prevention system for the rotor of a high-speed magnetic levitation motor 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 signal of the rotor is obtained through the displacement sensor, and according to the above-mentioned vibration prevention method for the rotor of the high-speed magnetic levitation motor, the input and output signals of the controller are compensated to control the vibration of the rotor.

[0012] An electronic device includes: a memory for storing a computer program; a processor for executing the computer program so that the device executes the above-mentioned vibration prevention method for the rotor of the high-speed magnetic levitation motor.

[0013] A computer-readable storage medium stores a computer program thereon. When the computer program is run, the device running the computer program implements the above-mentioned vibration prevention method for the rotor of the high-speed magnetic levitation motor.

[0014] Beneficial effects: The vibration prevention method, system, electronic device, and medium for the rotor of the high-speed magnetic levitation motor disclosed by the present invention have the following beneficial effects: 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 an unbalance suppression method of phase compensation. By using the frequency sweep method to determine two compensation matrices and storing them in the EEPROM of the controller's storage medium, one matrix is used to reduce the magnetic bearing force, and one matrix is used to compensate for the phase to reduce the displacement, realizing the dual-matrix vibration prevention control of the high-speed magnetic levitation rotor that can both reduce the magnetic bearing force and reduce the displacement.

[0015] 2. The present invention obtains the compensation matrix by the pre-frequency sweep method and stores it in the EEPROM. During actual control, a lot of complex calculations are omitted, and the corresponding compensation matrix can be directly retrieved according to the operating conditions of the motor for calculation, reducing the computing power requirement for the controller and being easy to implement in engineering. Description of the Drawings

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

[0017] Figure 1 It is a schematic structural diagram of a single-degree-of-freedom magnetic levitation bearing system; Figure 2 It is a schematic diagram of applying excitation when obtaining the response matrix AVC0' of the present invention; Figure 3Schematic diagram of applying excitation when obtaining the response matrix AVC2' for the present invention; Figure 4 Schematic diagram of using the compensation matrix for rotor vibration prevention control in the present invention; Figure 5 Schematic diagram of the 5 degrees of freedom of the magnetic bearing in the present invention; Among them, 1 - electromagnet, 2 - rotor, 3 - displacement sensor, 4 - controller, 5 - power amplifier. Detailed implementation manner

[0018] Now, reference will be made in detail to the embodiments of the present disclosure, one or more examples of which are set forth below. Each embodiment and example is provided by way of explanation of the apparatus, composition, and materials of the present disclosure, rather than by way of limitation. On the contrary, the following description provides a convenient illustration for implementing the exemplary embodiments of 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.

[0019] As Figures 1-5 shown, the present invention discloses a method for preventing vibration of a high - speed magnetic levitation motor rotor, including the steps: S01. The rotor maintains a suspended state, and within the full speed range of the motor, a sweep frequency is performed to obtain the response matrix AVC0' of the response signal corresponding to the input of the controller after subtracting the excitation signal from the displacement signal output by the displacement sensor. As Figure 2 shown, in the figure, the position a represents the reference displacement signal, denoted by Ref, representing the suspension center of the rotor; the position g represents the output of the displacement sensor, denoted by Vposition, q0 is the excitation signal 0, denoted by Excitation0; the position b is the input of the controller, denoted by En, and the input signal En = Ref - Vposition - Excitation0.

[0020] The position c represents the output of the controller, which is also the input of the power amplifier, represented by voltage, the position e represents the output voltage of the power amplifier, the position f is the magnetic bearing current. Subtracting the excitation signal 0 at the position q0 in the figure will obtain a response at the position b of the controller. The response matrix AVC0' of the signal change can be obtained according to the response signal corresponding to the excitation signal frequency and the relationship between the response signal and the original excitation signal.

[0021] S02. The rotor maintains a suspended state, and within the full speed range of the motor, a sweep frequency is performed to obtain the response matrix AVC2' of the response signal corresponding to the output of the displacement sensor after adding the excitation signal to the control signal output by the controller. As Figure 3As shown, the position a represents the reference displacement signal, denoted by Ref, corresponding to the suspension center of the rotor; the position g represents the output of the displacement sensor, denoted by Vposition, q2 is the excitation signal 2, denoted by Excitation2; the position b is the input of the controller, denoted by En. Since all electrical signals are sine signals and can be directly superimposed on each other, the controller input signal En = Ref - Vposition.

[0022] The position c represents the output of the controller, denoted by U4; the position h represents the input of the power amplifier, and the power amplifier input is equal to Excitation2 + U4. The position e represents the output voltage of the power amplifier (abbreviation: power amplifier), and the position f is the magnetic bearing current.

[0023] When the excitation signal 2 is applied at q2, the input of the power amplifier changes, which is finally reflected in the change of the output of the displacement sensor, that is, the change of Vposition at the position g. The response matrix AVC2’ is obtained according to the change of the response signal generated at the position g with the excitation signal 2.

[0024] In steps S01 and S02, the present invention represents the electrical signals in the form of complex numbers, obtains the real and imaginary part changes of the response signal with respect to the excitation signal, and obtains the corresponding response matrix between the two. The excitation signal is a sine signal with a frequency ranging from 10 Hz to the rated speed frequency of the motor, and the step size is 10 Hz or 20 Hz. The step size can be selected based on the controller EEPROM memory and the requirement for the rotor vibration control accuracy. By changing the corresponding excitation frequency, the corresponding compensation matrix at different motor speeds can be obtained, so as to be able to control and compensate the rotor vibration under different operating conditions during the operation of the magnetic levitation motor.

[0025] S03. Take the inverse matrices of the response matrices AVC0’ and AVC2’ obtained in steps S01 and S02 to obtain the compensation matrices AVC0 and AVC2, and store the compensation matrices in the controller EEPROM. When performing rotor vibration control, compensate the electrical signals at the corresponding positions where the excitation signals are applied in steps S01 and S02 by retrieving the compensation matrices.

[0026] As Figure 3 shown, when using the compensation matrix for vibration control, when using AVC0, extract the signal at the controller input and insert it at Ref - Vposition; when using AVC2, extract the signal at Ref - Vposition and insert it at the controller output.

[0027] In step S03 of the present invention, the process of compensating the electrical signals using the compensation matrix includes: S031. Generate the corresponding sine avcSin and cosine avcCos with the same frequency according to the sine function corresponding to the electrical signal; S032. Confirm the rotation angle range of the rotor within the current period. After multiplying the sine function by the corresponding sine and cosine of the same frequency respectively, performing periodic summation and averaging, obtain the real part axis_s and the imaginary part axis_c of the complex representation of the electrical signal. Assume a sine signal , with amplitude A and initial phase angle ; generate a sine and a cosine of the same frequency as this sine signal; Multiply this sine signal by its sine and cosine of the same frequency respectively to obtain: ; ; After performing low-pass filtering or periodic summation on the above formula and then taking the average value, the real part is ; the imaginary part is ; Then the amplitude ; The initial phase .

[0028] For each control period of the controller, it is necessary to calculate the change in the rotor angle within a control period according to the control period Ts and the current frequency f; and based on the rotor angle position in the previous period, obtain the rotor angle = + .

[0029] At this time, the sine of the same frequency avcSin = and the cosine of the same frequency avcCos = ), calculate the axis_s and axis_c corresponding to the rotor angle within a control period.

[0030] S033. And based on the product of the compensation matrix and the real part axis_s and the imaginary part axis_c of the electrical signal, obtain the compensation function for the electrical signal: AVCComp = (comp_s * avcSin + comp_c * avcCos), where comp_s and comp_c are the real part and the imaginary part of the corresponding matrix after calculation respectively; correspondingly, obtain the compensation function AVCComp0 corresponding to the compensation matrix AVC0 and the compensation function AVCComp2 corresponding to the compensation matrix AVC2.

[0031] Such as Figure 5As shown, the conventional rotor has five degrees of freedom of movement in different directions and a degree of freedom of rotation along the circumferential direction of the rotor. For the vibration control of the rotor, it is achieved by changing the five degrees of freedom of movement of the rotor through magnetic bearings. In the figure, X1 and Y1 are the upper radial directions, X2 and Y2 are the lower radial directions, and Z is the axial direction, denoted as axi.

[0032] In the present invention, taking the z-axis as an example, the process of establishing a compensation function through a compensation matrix in the present invention will be described.

[0033] Compensation matrix As the transfer function between signal input and output; in the 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, and axi_comp_c is the imaginary part of the compensation function.

[0034] In addition, when the present invention uses the compensation matrix AVC2 for phase compensation, it is necessary to limit the amplitude of AVCComp2 to avoid excessive reduction of displacement vibration resulting in saturation of the power amplifier current and increasing unnecessary losses; calculate the modulus value of the current compensation function; and compare the modulus value with the modulus value AMP_Last of the compensation function in 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 amount output by the displacement sensor is less than 10% of the clearance, and AMP is greater than AMP_Last, then the compensation is limited, and at this time, the limit = AMP_Last; as Figure 1 shown, a control signal is generated by the controller 4, and a corresponding control current is generated by the power amplifier 5 so that the electromagnet 1 can generate magnetic force to control the stable suspension of the rotor 2; the bias current is the basic current continuously present in the electromagnetic bearing coil, which is used to maintain the stable suspension of the rotor without external interference or control signal. When performing vibration control, it is necessary to correspondingly increase or decrease the bias current passed through the coil on the corresponding electromagnet 1; the clearance is the movable stroke of the rotor. When the rotor floats in the center, the unilateral distance from the protection bearing multiplied by 2 can obtain the clearance.

[0035] Preferably, in steps S01 and S02 of the present invention, by using the form of representing the electrical signal in complex numbers, the real part and the imaginary part changes of the response signal relative to the excitation signal are obtained, and the corresponding response matrix between the two is obtained.

[0036] A vibration prevention system for a high-speed magnetic levitation motor rotor, comprising 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 displacement signal of the rotor is obtained through the displacement sensor, and the input and output signals of the controller are compensated according to the above-mentioned vibration prevention method for the high-speed magnetic levitation motor rotor, so as to control the vibration of the rotor.

[0037] An electronic device, comprising: a memory for storing matrix data; a processor for executing the computer program to enable the device to execute the above-mentioned vibration prevention method for the high-speed magnetic levitation motor rotor.

[0038] A computer-readable storage medium, on which matrix data is stored. When the computer program is run, the device running the computer program implements the above-mentioned vibration prevention method for the high-speed magnetic levitation motor rotor.

[0039] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A high-speed magnetic levitation motor rotor vibration prevention method, characterized in that: Includes steps: S01, the rotor is kept in suspension state, and the frequency is swept in 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 input end of the controller; S02, the rotor is kept in suspension state, and the control signal output by the controller is scanned in the full speed range of the motor to obtain the response matrix AVC2' corresponding to the response signal at the output end of the displacement sensor after the excitation signal is added; S03. Take the inverse matrix of the response matrices AVC0' and AVC2' obtained in step S01 and step 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.

2. The high-speed magnetic levitation motor rotor vibration protection method according to claim 1 is 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 prevention method according to claim 1 is characterized in that: In step S03, the process of using the compensation matrix to compensate the electrical signal includes: S031. Generate corresponding sine avcSin and cosine avcCos of the same frequency according to the sine function corresponding to the electrical signal; S032, confirming the rotation angle range of the rotor in the current cycle, and multiplying the sine function with the corresponding sine and cosine of the same frequency to perform period summing and averaging, to obtain the real part axis_s and the 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), wherein comp_s and comp_c are the real part and the imaginary part of the corresponding matrix after calculation, respectively.

4. The high-speed magnetic levitation motor rotor vibration prevention method according to claim 3 is 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.

5. The high-speed magnetic levitation motor rotor vibration prevention 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 changes of the response signal relative to the excitation signal, thereby obtaining a corresponding response matrix between the two.

6. A high-speed magnetic suspension motor rotor vibration protection 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, the coil of the magnetic bearing is connected to the power amplifier, the displacement signal of the rotor is obtained through the displacement sensor, and the input and output signals of the controller are compensated according to the high-speed magnetic levitation motor rotor vibration protection method described in any one of claims 1 to 5, so as to control the vibration of the rotor.

7. 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 executes the high-speed magnetic levitation motor rotor vibration protection method as described in any one of claims 1-6.

8. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program. When the computer program is executed, a device executing the computer program implements the high-speed magnetic levitation motor rotor vibration protection method according to any one of claims 1 to 6.

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