Vibration suppression method, device and system for rotor in magnetic bearing system

Abstract

The present invention relates to a method, device, and system for suppressing rotor vibration in a magnetic bearing system, belonging to the field of magnetic bearing control technology. The method comprises: predicting a second displacement signal of the rotor at the current moment based on the current signal of the magnetic bearing winding at the current moment and the first displacement signal of the rotor at the previous moment; determining a current compensation signal based on the rotor's rotational frequency and the second displacement signal determined by the current signal of the winding at the current moment; and superimposing the current compensation signal and the original current command to obtain a target current command. The method provided by the present invention can extract the rotational frequency and rotor position without installing a position sensor inside the motor, greatly optimizing the motor's structural design and avoiding operational instability and maintenance costs caused by sensor damage. It can effectively implement a vibration suppression algorithm in magnetic bearing systems where sensors are not installed or cannot be installed, effectively suppressing rotor vibration.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic bearing control, and in particular to a method, device and system for suppressing vibration of a rotor in a magnetic bearing system. Background Art

[0002] Active magnetic bearings (AMBs), also known as active magnetic bearings, are currently the most widely used type of magnetic bearing. Because they lack mechanical contact and are dynamically controllable, they offer advantages over traditional mechanical bearings, such as long life, simple structure, and low noise. In many applications requiring high-speed motors, active magnetic bearings have been used to support rotor rotation, eliminating friction and providing active control. Vibration is a common problem in rotating machinery. Due to their mechanical properties, traditional bearings struggle to address vibrations caused by stiffness. Active magnetic bearings, however, offer controllable stiffness, making vibration suppression possible. Furthermore, due to the unique structure of some high-speed motors, sensors such as rotary encoders or displacement sensors cannot be installed. Therefore, real-time observation of the speed and rotor position is required while implementing the magnetic suspension system control algorithm.

[0003] Radial displacement vibration of the magnetic bearing rotor during motor rotation is a common problem in magnetic bearing systems. Due to machining errors, the rotor's geometric center and center of gravity do not coincide, generating centrifugal forces during rotor rotation. In magnetic bearing systems, this centrifugal force causes centrifugal displacement of the rotor, which in turn induces current fluctuations through sensors and controllers. Furthermore, resonant frequencies exist in the rotor's first and second modes, making the system more susceptible to instability at specific speeds, leading to mechanical collisions.

[0004] Existing magnetic bearing control methods and vibration suppression algorithms often require the use of speed sensors or displacement sensors. However, in practice, the unique structures of some high-speed motors make speed sensors and displacement sensors difficult to install, making vibration suppression in these magnetic bearing systems difficult to achieve. Summary of the Invention

[0005] In view of this, it is necessary to provide a method, device and system for suppressing vibration of a rotor in a magnetic bearing system, so as to solve the problem of how to suppress the vibration of the rotor without using a position sensor.

[0006] In order to solve the above problems, in a first aspect, the present invention provides a method for suppressing vibration of a rotor in a magnetic bearing system, comprising:

[0007] Predicting a second displacement signal of the rotor at the current moment based on a current signal of a winding of the magnetic bearing at the current moment and a first displacement signal of the rotor at the previous moment;

[0008] Determine a current compensation signal based on the rotor speed frequency determined by the current signal of the winding at the current moment and the second displacement signal; determine a current compensation signal based on the second displacement signal and the rotor speed frequency;

[0009] The current compensation signal and the original current instruction are superimposed to obtain a target current instruction; the target current instruction is used to indicate the generation of a target current signal in the winding; the target current signal is used to suppress the vibration of the rotor.

[0010] In a possible implementation, predicting a second displacement signal of the rotor at the current moment based on a current signal of the winding of the magnetic bearing at the current moment and a first displacement signal of the rotor at the previous moment includes:

[0011] Inputting the current signal and the first displacement signal into a trained prediction model to obtain the second displacement signal output by the prediction model;

[0012] The prediction model is obtained by training the RNN algorithm based on historical current signals and historical displacement signals.

[0013] In a possible implementation, before determining the current compensation signal based on the rotor speed frequency determined by the current signal of the winding at the current moment and the second displacement signal, the method further includes:

[0014] Using a high-pass filter to filter out a DC component in the current signal to obtain a filtered current signal;

[0015] A phase-locked loop is used to extract the frequency of the filtered current signal to obtain the rotational speed frequency.

[0016] In a possible implementation, determining the current compensation signal based on the rotor speed frequency determined by the current signal of the winding at the current moment and the second displacement signal includes:

[0017] The second displacement signal and the rotational speed frequency are input into a quasi-proportional resonator to obtain the current compensation signal.

[0018] In a possible implementation, before superimposing the current compensation signal and the original current command to obtain the target current command, the method further includes:

[0019] The original current command is determined based on the second displacement signal and a preset reference displacement command.

[0020] In a possible implementation, before predicting the second displacement signal of the rotor at the current moment based on the current signal of the winding of the magnetic bearing at the current moment and the first displacement signal of the rotor at the previous moment, the method further includes:

[0021] The current sensor is used to collect the current signal of the winding on any radial degree of freedom of the magnetic bearing.

[0022] In a second aspect, the present invention further provides a vibration suppression device for a rotor in a magnetic bearing system, comprising:

[0023] a displacement prediction model for predicting a second displacement signal of the rotor at a current moment based on a current signal of a winding of the magnetic bearing at a current moment and a first displacement signal of the rotor at a previous moment;

[0024] a quasi-proportional resonator, configured to determine a current compensation signal based on a rotational speed frequency of the rotor determined by a current signal of the winding at a current moment and the second displacement signal;

[0025] A power amplifier is used to superimpose the current compensation signal and the original current instruction to obtain a target current instruction; the target current instruction is used to indicate the generation of a target current signal in the winding; the target current signal is used to suppress the vibration of the rotor.

[0026] In a possible implementation, the method further includes:

[0027] a high-pass filter, configured to filter out a DC component in the current signal to obtain a filtered current signal;

[0028] A phase-locked loop is used to extract the frequency of the filtered current signal to obtain the rotational speed frequency.

[0029] In a possible implementation, the method further includes:

[0030] The controller is configured to determine the original current instruction based on the second displacement signal and a preset reference displacement instruction.

[0031] In a third aspect, the present invention further provides a magnetic bearing system, comprising the vibration suppression device for a rotor in the magnetic bearing system described in any of the above implementations.

[0032] The beneficial effects of the present invention are as follows: the vibration suppression method, device and system of the rotor in the magnetic levitation bearing system provided by the present invention predict the second displacement signal of the rotor at the current moment according to the current signal of the winding at the current moment and the first displacement signal of the rotor at the previous moment by using a neural network algorithm, and determine the rotational speed frequency according to the current signal. The rotational frequency and rotor position can be extracted without installing a position sensor inside the motor, which can greatly optimize the structural design of the motor, simplify the system architecture, avoid the working instability and maintenance cost caused by sensor damage, and determine the current compensation signal according to the second displacement signal and the rotational speed frequency of the rotor. The current compensation signal and the original current instruction are superimposed to obtain the target current instruction, thereby generating a target current signal in the winding to suppress the vibration of the rotor. The current compensation signal is introduced through the radial displacement and the winding current signal, which can effectively implement the vibration suppression algorithm in the magnetic bearing system where the sensor is not installed or cannot be installed, and effectively suppress the vibration of the rotor. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 This is a flow chart of one embodiment of a method for suppressing vibration of a rotor in a magnetic bearing system provided by the present invention;

[0035] Figure 2 This is one of the trajectory tracking schematic diagrams of the prediction model provided by the present invention;

[0036] Figure 3 This is the second trajectory tracking diagram of the prediction model provided by the present invention;

[0037] Figure 4 A schematic structural diagram of a quasi-proportional resonator provided by the present invention;

[0038] Figure 5 A schematic structural diagram of an embodiment of a vibration suppression device for a rotor in a magnetic bearing system provided by the present invention;

[0039] Figure 6 This is a second flow chart of an embodiment of a method for suppressing vibration of a rotor in a magnetic bearing system provided by the present invention;

[0040] Figure 7 This is a diagram of the simulation results of single-degree-of-freedom displacement vibration suppression of the magnetic levitation bearing control system provided by the present invention. DETAILED DESCRIPTION

[0041] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making any creative efforts shall fall within the scope of protection of the present invention.

[0042] In the description of the embodiments of the present invention, unless otherwise specified, "plurality" means two or more. "And / or" describes the association relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, or B exists alone.

[0043] The terms "first," "second," and so on, used in the embodiments of the present invention are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, technical features designated as "first" or "second" may explicitly or implicitly include at least one such feature.

[0044] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute a separate or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0045] The present invention provides a method, device and system for suppressing vibration of a rotor in a magnetic bearing system, which are described below respectively.

[0046] Figure 1 This is a flow chart of an embodiment of a method for suppressing vibration of a rotor in a magnetic bearing system provided by the present invention, as shown in FIG. Figure 1 As shown, the vibration suppression method of the rotor in the magnetic bearing system includes:

[0047] S101 : Predicting a second displacement signal of the rotor at the current moment based on a current signal of a winding of a magnetic bearing at the current moment and a first displacement signal of a rotor at the previous moment.

[0048] In step S101 , the current signal may be a current signal of a winding corresponding to any radial degree of freedom of the magnetic bearing at the current moment.

[0049] Based on the current current signal and the displacement signal from the previous moment, a neural network algorithm can accurately predict the rotor's second displacement signal at the current moment. This eliminates the need to install a position sensor inside the motor to obtain the rotor's displacement signal. This significantly optimizes the motor's structural design, simplifies the system architecture, and avoids operational instability and maintenance costs caused by sensor damage.

[0050] Neural network algorithms can learn and capture complex input-output relationships. By training the neural network model, it learns the potential correlation between the current signal and the displacement signal. This allows accurate prediction of the rotor's second displacement signal at the current moment based on the current current signal and the displacement signal at the previous moment. Neural network algorithms can be recurrent neural networks, decision trees, or support vector regression algorithms.

[0051] It is understandable that after the second displacement signal at the current moment is predicted, the second displacement signal and the current signal at the next moment can be used to predict the displacement signal at the next moment.

[0052] S102 : Determine a current compensation signal based on the rotational speed frequency of the rotor determined by the current signal of the winding at the current moment and the second displacement signal.

[0053] In step S102, the rotational frequency of the magnetic bearing rotor can be observed through a phase-locked loop using the winding current signal collected by the radial degree of freedom.

[0054] A current compensation signal for suppressing vibration can be calculated by utilizing the rotational speed frequency and the second displacement signal.

[0055] S103. Superimpose the current compensation signal and the original current instruction to obtain a target current instruction; the target current instruction is used to indicate the generation of a target current signal in the winding; the target current signal is used to suppress the vibration of the rotor.

[0056] In step S103, the original current command can be determined based on the second displacement signal and the preset reference displacement command, and the calculated current compensation signal is superimposed on the original current command to obtain a target current command.

[0057] The target current command is input into the winding of the magnetic bearing system. The winding can generate a target current signal according to the target current command. The target current signal can change the magnetic field distribution around the winding, thereby applying a specific electromagnetic force to the rotor to suppress the vibration of the rotor.

[0058] By precisely controlling the target current signal, the electromagnetic force acting on the rotor can be adjusted in real time to offset or reduce the various disturbance forces that cause rotor vibration. This effectively suppresses rotor vibration and improves the stability and performance of the magnetic bearing system.

[0059] The embodiment of the present invention provides a vibration suppression method for a rotor in a magnetic bearing system. Based on the current signal of the winding at the current moment and the first displacement signal of the rotor at the previous moment, a neural network algorithm is used to predict the second displacement signal of the rotor at the current moment, and the rotational speed frequency is determined based on the current signal. The rotational frequency and rotor position can be extracted without installing a position sensor inside the motor. This can greatly optimize the structural design of the motor, simplify the system architecture, and avoid unstable operation and maintenance costs caused by sensor damage. A current compensation signal is determined based on the second displacement signal and the rotational speed frequency of the rotor. The current compensation signal and the original current instruction are superimposed to obtain a target current instruction, thereby generating a target current signal in the winding to suppress the vibration of the rotor. The current compensation signal is introduced through the radial displacement and the winding current signal. This can effectively implement a vibration suppression algorithm in a magnetic bearing system where a sensor is not installed or cannot be installed, and effectively suppress the vibration of the rotor.

[0060] In some embodiments of the present invention, before predicting the second displacement signal of the rotor at the current moment based on the current signal of the winding of the magnetic bearing at the current moment and the first displacement signal of the rotor at the previous moment, the method further includes:

[0061] The current sensor is used to collect the current signal of the winding on any radial degree of freedom of the magnetic bearing.

[0062] Magnetic bearings have multiple radial degrees of freedom, and the windings associated with each degree of freedom control the rotor's motion in that direction. Current sensors can be used to sample the current signal corresponding to the winding in a specific radial degree of freedom of the magnetic bearing.

[0063] In some embodiments of the present invention, the method of predicting a second displacement signal of the rotor at the current moment based on the current signal of the winding of the magnetic bearing at the current moment and the first displacement signal of the rotor at the previous moment includes:

[0064] Inputting the current signal and the first displacement signal into a trained prediction model to obtain the second displacement signal output by the prediction model;

[0065] The prediction model is obtained by training the RNN algorithm based on historical current signals and historical displacement signals.

[0066] The current position is predicted using a neural network algorithm based on the acquired current signal and the magnetic bearing displacement signal at the previous moment.

[0067] In an embodiment of the present invention, a prediction model is obtained by training an RNN algorithm, and the prediction model is trained and verified using a collected data set, where the data set includes historical current signals and historical displacement signals. The displacement observation of the magnetic bearing rotor is completed by adjusting the structural parameters and sequence length.

[0068] For example, Figure 2 and Figure 3 A schematic diagram of the trajectory tracking of the prediction model provided by the present invention is shown in FIG. Figure 2 and Figure 3 As shown in the figure, the prediction model can accurately predict the rotor displacement signal by making full use of historical data for training, and has high accuracy when processing the complex dynamic characteristics of the magnetic bearing system.

[0069] The rotor vibration suppression method for a magnetic bearing system, provided in an embodiment of the present invention, uses an RNN algorithm for model training. Leveraging the RNN's ability to process sequential data, it effectively captures the dependencies within time series information. By continuously iteratively updating the network's weight parameters, the model gradually learns the mapping relationship between the current signal and the previous displacement signal, and the subsequent displacement signal.

[0070] In some embodiments of the present invention, before determining the current compensation signal based on the rotor speed frequency determined by the current signal of the winding at the current moment and the second displacement signal, the method further includes:

[0071] Using a high-pass filter to filter out a DC component in the current signal to obtain a filtered current signal;

[0072] A phase-locked loop is used to extract the frequency of the filtered current signal to obtain the rotational speed frequency.

[0073] The magnetic bearing winding current signal first passes through a high-pass filter and then enters the phase-locked loop to obtain the rotation frequency of the magnetic bearing rotor, thereby inputting the predicted second displacement signal and speed frequency signal into the quasi-proportional resonator control link, and outputting a vibration suppression compensation signal of the current command.

[0074] The motor rotation frequency can be obtained from the current signal using a phase-locked loop. Since the phase-locked loop is more sensitive to DC components, a high-pass filter is added to the front end of the phase-locked loop to filter out the DC component in the current signal.

[0075] In some embodiments of the present invention, determining the current compensation signal based on the rotor speed frequency determined by the current signal of the winding at the current moment and the second displacement signal includes:

[0076] The second displacement signal and the rotational speed frequency are input into a quasi-proportional resonator to obtain the current compensation signal.

[0077] Figure 4 The schematic diagram of the structure of the quasi-proportional resonator provided by the present invention is as follows: Figure 4 As shown, by inputting the second displacement signal and the rotational speed frequency into a quasi-proportional resonator (QPR), a vibration suppression compensation signal of the current command can be obtained.

[0078] The quasi-proportional resonator has a large gain at the resonant frequency and also has a certain gain bandwidth, which can ensure the stability of the system while suppressing vibration.

[0079] The vibration suppression method for the rotor in the magnetic bearing system provided by the embodiment of the present invention inputs the second displacement signal and the rotational speed frequency into a quasi-proportional resonator to obtain a current compensation signal. The quasi-proportional resonator has a large gain at the resonant frequency and also has a certain gain bandwidth, which can ensure the stability of the system while suppressing vibration.

[0080] In some embodiments of the present invention, before superimposing the current compensation signal and the original current instruction to obtain the target current instruction, the method further includes:

[0081] The original current command is determined based on the second displacement signal and a preset reference displacement command.

[0082] Through the predicted second displacement signal and the preset reference displacement instruction of the system, the original current instruction can be obtained through the position outer loop calculation.

[0083] Exemplarily, the second displacement signal is converted into an electrical signal to obtain the original radial displacement, and the displacement difference signal between the original radial displacement and the preset reference displacement instruction is input into the displacement controller. The displacement controller uses the control algorithm to process the displacement difference signal to obtain the corresponding original current instruction.

[0084] This invention utilizes an observation algorithm to derive speed and displacement signals from current signals, thereby implementing a vibration suppression algorithm for magnetic bearings. Its basic control algorithm includes an outer position loop, an inner current loop, a frequency observer, a displacement observer, and a vibration suppression feedforward compensation algorithm. This algorithm reduces radial displacement vibration of the magnetic bearing rotor, preventing vibration-induced system instability and damage from mechanical collisions. Unlike current mainstream methods, this invention obtains both displacement information and speed and frequency through current signal observation, expanding the application scenarios of this control algorithm.

[0085] Figure 5 A schematic structural diagram of an embodiment of a vibration suppression device for a rotor in a magnetic bearing system provided by the present invention is shown in FIG. Figure 5 As shown, the vibration suppression device 500 for a rotor in a magnetic bearing system provided by an embodiment of the present invention includes:

[0086] A displacement prediction model 501 is configured to predict a second displacement signal of the rotor at a current moment based on a current signal of a winding of the magnetic bearing at a current moment and a first displacement signal of the rotor at a previous moment;

[0087] a quasi-proportional resonator 502, configured to determine a current compensation signal based on the rotor speed frequency determined by the current signal of the winding at a current moment and the second displacement signal;

[0088] The power amplifier 503 is used to superimpose the current compensation signal and the original current instruction to obtain a target current instruction; the target current instruction is used to indicate the generation of a target current signal in the winding; the target current signal is used to suppress the vibration of the rotor.

[0089] The vibration suppression device for a rotor in a magnetic bearing system provided by an embodiment of the present invention utilizes a displacement prediction model to predict a second displacement signal of the rotor at the current moment based on a current signal of the winding at the current moment and a first displacement signal of the rotor at the previous moment, using a neural network algorithm, and determines the rotational speed frequency based on the current signal. This device can extract the rotational frequency and rotor position without installing a sensor inside the motor, thereby greatly optimizing the structural design of the motor, simplifying the system architecture, and avoiding operational instability and maintenance costs caused by sensor damage. Furthermore, a quasi-proportional resonator is used to determine a current compensation signal based on the second displacement signal and the rotational speed frequency of the rotor, and a power amplifier is used to superimpose the current compensation signal and the original current command to obtain a target current command, thereby generating a target current signal in the winding to suppress rotor vibration. By introducing the current compensation signal through radial displacement and the winding current signal, the device can effectively implement a vibration suppression algorithm in a magnetic bearing system where sensors are not installed or cannot be installed, adjust the system stiffness, and thereby solve problems such as mechanical device damage caused by excessive radial displacement at different speeds.

[0090] In some embodiments of the present invention, further comprising:

[0091] A high-pass filter 504 is used to filter out the DC component in the current signal to obtain a filtered current signal;

[0092] The phase-locked loop 505 is used to extract the frequency of the filtered current signal to obtain the rotational speed frequency.

[0093] The magnetic bearing winding current signal first passes through a high-pass filter and then enters the phase-locked loop to obtain the rotation frequency of the magnetic bearing rotor, thereby inputting the predicted second displacement signal and speed frequency signal into the quasi-proportional resonator control link, and outputting a vibration suppression compensation signal of the current command.

[0094] The motor rotation frequency can be obtained from the current signal using a phase-locked loop. Since the phase-locked loop is more sensitive to DC components, a high-pass filter is added to the front end of the phase-locked loop to filter out the DC component in the current signal.

[0095] In some embodiments of the present invention, further comprising:

[0096] The controller 506 is configured to determine the original current instruction based on the second displacement signal and a preset reference displacement instruction.

[0097] Through the predicted second displacement signal and the preset reference displacement instruction of the system, the original current instruction can be obtained through the position outer loop calculation.

[0098] Exemplarily, the second displacement signal is converted into an electrical signal to obtain the original radial displacement, and the displacement difference signal between the original radial displacement and the preset reference displacement instruction is input into the displacement controller. The displacement controller uses the control algorithm to process the displacement difference signal to obtain the corresponding original current instruction.

[0099] The present invention obtains the current signal of the radial degree of freedom of the magnetic bearing, obtains the speed frequency signal through phase-locked loop observation, obtains the displacement signal through machine learning model, calculates the original current command signal using the displacement signal, obtains the current compensation signal based on the speed frequency and radial displacement signal, and feedforwards and superimposes the original current command and the current compensation signal to obtain the actual target current command. The actual current generated enables the magnetic bearing to achieve more stable suspension at the speed. The present invention can effectively suppress the radial vibration of the magnetic bearing rotor and improve the stability of the magnetic bearing during the speed increase process. The corresponding observation algorithm solves the problem that sensors such as rotary encoders or position sensors cannot be installed due to the special structure of high-speed motors.

[0100] Based on the vibration suppression device for a rotor in a magnetic bearing system in the above embodiments, the present invention further provides a magnetic bearing system, including the vibration suppression device for a rotor in a magnetic bearing system described in any of the above implementations.

[0101] The magnetic bearing system only requires a current signal to suppress the displacement vibration of the magnetic bearing, thereby solving the collision and damage of mechanical components caused by the radial displacement of the magnetic bearing rotor at different speeds and improving the reliability and stability of the system.

[0102] That is, the present invention proposes a vibration suppression control method for a magnetic bearing system based on a position sensorless system. The advantage is that only a current signal is required to achieve displacement vibration suppression of the magnetic bearing, thereby solving the collision and damage of mechanical components caused by radial displacement of the magnetic bearing rotor at different speeds, and improving the reliability and stability of the system.

[0103] By using the winding current signal collected from the radial degrees of freedom, the magnetic bearing speed frequency is observed through a phase-locked loop (PLL), and the current position of the magnetic bearing is predicted using the position signal and current signal at the previous moment. A vibration suppression current compensation signal is calculated using the speed frequency and displacement signal, and the current command signal is fed forward to achieve sensorless vibration suppression of the magnetic bearing at different speeds.

[0104] For example, Figure 6 This is a second flow chart of an embodiment of a method for suppressing vibration of a rotor in a magnetic bearing system provided by the present invention, as shown in FIG. Figure 6 As shown, the vibration suppression method of the rotor in the magnetic bearing system includes:

[0105] S601: Acquire a winding current signal corresponding to a certain radial degree of freedom of the magnetic bearing in the current state through sampling by a current sensor.

[0106] S602 : Predicting the current position using a neural network algorithm based on the acquired current signal and the magnetic bearing displacement signal at the previous moment.

[0107] Among them, the location prediction algorithm uses the RNN algorithm for model training.

[0108] S603 , using the predicted displacement signal and a reference displacement instruction preset by the system, an original current instruction is calculated through a position outer loop.

[0109] S604: The collected current signal is passed through a phase-locked loop to obtain a rotational speed frequency observation signal, and a current compensation signal for vibration suppression is calculated based on the predicted displacement signal and the rotational speed frequency observation signal.

[0110] Among them, the magnetic bearing winding current signal first passes through a high-pass filter and then enters the phase-locked loop to obtain the rotation frequency of the magnetic bearing rotor. The predicted displacement signal and speed frequency signal are input into the quasi-proportional resonator control link to output the vibration suppression compensation signal of the current command.

[0111] S605 , feed-forward the current compensation signal and add it to the original current signal to obtain a system target current command.

[0112] S606: Generate a corresponding current signal in the magnetic bearing winding using the system target current instruction through the current loop to adjust the suspension state of the magnetic bearing system.

[0113] The magnetic bearing system is a typical high-order nonlinear system. Its nonlinear characteristics are primarily due to the nonlinearity of the force-current-displacement relationship. However, when the shaft deviates slightly from the center, the electromagnetic force can be expressed as a linear combination of the shaft's eccentric displacement and the control current, thus achieving linearization of the electromagnetic force. Two adjacent magnetic poles form a pair that exerts an attractive force on the rotor, while the opposing pair also exerts electromagnetic attraction. The differential action of these two pole pairs controls one degree of freedom of the rotor.

[0114] The power amplifier can usually be approximated as linear, so the transfer function from centrifugal force to displacement in the system can be expressed as:

[0115] (1)

[0116] in, The dynamic equation of the rotor with a single degree of freedom under the influence of electromagnetic force is expressed as follows: represents the controller transfer function, represents the current stiffness of the magnetic bearing, Indicates the sensor sampling gain.

[0117] make , and substitute into formula (1) to obtain:

[0118] (2)

[0119] (3)

[0120] in, 、 、 Represent PID control parameters respectively, represents the displacement stiffness of the magnetic bearing, represents the mass of the magnetic bearing rotor, Indicates the angular velocity of rotation.

[0121] In steady state, the centrifugal force can be expressed as:

[0122] (4)

[0123] in, represents the eccentricity, is the angular velocity of rotation, is the initial phase value of the centrifugal force.

[0124] Therefore, the vibration amplitude of the displacement can be expressed as:

[0125] (5)

[0126] According to the expression of vibration amplitude, when the PID parameters remain unchanged, increasing Can effectively suppress vibration, however, as As the gain of increases, the introduced noise gain also increases, affecting the stability of the system. To reduce vibration, it is sufficient to increase the controller gain. However, the proportional resonant controller has infinite gain at its resonant frequency. Applying a proportional resonant controller in the displacement control loop can effectively suppress vibration in the displacement.

[0127] However, in practical applications, proportional resonators cannot effectively suppress vibrations caused by rotational frequency due to fluctuations in rotational speed. Therefore, quasi-proportional resonators are often more widely used. QPR has a large gain at the resonant frequency and a certain gain bandwidth, which can ensure system stability while suppressing vibrations.

[0128] The motor rotation frequency is obtained from the current signal using a phase-locked loop. Since the phase-locked loop is sensitive to DC components, a high-pass filter is added at the front end to filter out the DC components. The specific control block diagram is as follows: Figure 4 shown.

[0129] When QPR is applied to the control loop, the transfer function of the system centrifugal force to displacement is:

[0130] (6)

[0131] in, 、 are the control parameters of the quasi-proportional resonator, represents the quasi-proportional resonator cutoff frequency, represents the resonant frequency of the quasi-proportional resonator, Represents the cutoff frequency of the power amplifier transfer function.

[0132] Figure 7 This is the simulation result diagram of the single-degree-of-freedom displacement vibration suppression of the magnetic bearing control system provided by the present invention. The Bode diagram of the transfer function corresponding to formula (6) is as follows: Figure 7 As shown in the figure, the gain of the QPR controller at the set resonant frequency is significantly lower than that of the traditional PID control. If the resonant frequency parameter always follows the rotation frequency, the displacement of the magnetic bearing system will not be affected by the centrifugal force, so the displacement vibration caused by the motor rotation will be suppressed.

[0133] The vibration suppression method for a rotor in a magnetic bearing system provided by the present invention has the following advantages:

[0134] (1) By collecting the winding current signal, the rotor displacement and rotation frequency at the corresponding degree of freedom are obtained. The rotation frequency and rotor position can be extracted without installing sensors inside the motor. This can greatly optimize the structural design of the motor, simplify the system architecture, and avoid unstable operation and maintenance costs caused by sensor damage.

[0135] (2) By introducing the current compensation signal through the radial displacement and winding current signal, the vibration suppression algorithm can be effectively implemented in the magnetic bearing system where the sensor is not installed or cannot be installed, and the system stiffness can be adjusted, thereby solving the problem of mechanical device damage caused by excessive radial displacement at different speeds.

[0136] Those skilled in the art will appreciate that all or part of the process flow of the above-described method embodiment can be implemented by instructing related hardware (such as a processor, controller, etc.) through a computer program, and the computer program can be stored in a computer-readable storage medium. The computer-readable storage medium may be a magnetic disk, an optical disk, a read-only memory, or a random access memory.

[0137] The above is a detailed introduction to the vibration suppression method, device and system for the rotor in the magnetic bearing system provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas. At the same time, for technical personnel in this field, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for suppressing vibration of a rotor in a magnetic bearing system, characterized in that: include: Predicting a second displacement signal of the rotor at the current moment based on a current signal of a winding of the magnetic bearing at the current moment and a first displacement signal of the rotor at the previous moment; determining a current compensation signal based on the rotational speed frequency of the rotor determined by the current signal of the winding at the current moment and the second displacement signal; Superimposing the current compensation signal and the original current command to obtain a target current command; The target current instruction is used to instruct the generation of a target current signal in the winding; The target current signal is used to suppress vibration of the rotor; The method of predicting a second displacement signal of the rotor at the current moment based on the current signal of the winding of the magnetic bearing at the current moment and the first displacement signal of the rotor at the previous moment includes: Inputting the current signal and the first displacement signal into a trained neural network prediction model to obtain the second displacement signal output by the neural network prediction model; The neural network prediction model is obtained by training the RNN algorithm based on historical current signals and historical displacement signals.

2. The method for suppressing rotor vibration in a magnetic bearing system according to claim 1, characterized in that: Before determining the current compensation signal based on the rotor speed frequency determined by the current signal of the winding at the current moment and the second displacement signal, the method further includes: Using a high-pass filter to filter out a DC component in the current signal to obtain a filtered current signal; A phase-locked loop is used to extract the frequency of the filtered current signal to obtain the rotational speed frequency.

3. The method for suppressing rotor vibration in a magnetic bearing system according to claim 1, characterized in that: The determining of the current compensation signal based on the rotor speed frequency determined by the current signal of the winding at the current moment and the second displacement signal includes: The second displacement signal and the rotational speed frequency are input into a quasi-proportional resonator to obtain the current compensation signal.

4. The method for suppressing vibration of a rotor in a magnetic bearing system according to claim 1, characterized in that: Before superimposing the current compensation signal and the original current instruction to obtain the target current instruction, the method further includes: The original current command is determined based on the second displacement signal and a preset reference displacement command.

5. The method for suppressing vibration of a rotor in a magnetic bearing system according to claim 1, characterized in that: Before predicting the second displacement signal of the rotor at the current moment based on the current signal of the winding of the magnetic bearing at the current moment and the first displacement signal of the rotor at the previous moment, the method further includes: The current sensor is used to collect the current signal of the winding on any radial degree of freedom of the magnetic bearing.

6. A vibration suppression device for a rotor in a magnetic bearing system, which implements the vibration suppression method for a rotor in a magnetic bearing system according to any one of claims 1 to 5, characterized in that: include: a displacement prediction model for predicting a second displacement signal of the rotor at a current moment based on a current signal of a winding of the magnetic bearing at a current moment and a first displacement signal of the rotor at a previous moment; a quasi-proportional resonator, configured to determine a current compensation signal based on a rotational speed frequency of the rotor determined by a current signal of the winding at a current moment and the second displacement signal; A power amplifier, configured to superimpose the current compensation signal and the original current instruction to obtain a target current instruction; The target current instruction is used to instruct the generation of a target current signal in the winding; the target current signal is used to suppress the vibration of the rotor.

7. The vibration suppression device for a rotor in a magnetic bearing system according to claim 6, characterized in that: Also includes: a high-pass filter, configured to filter out a DC component in the current signal to obtain a filtered current signal; A phase-locked loop is used to extract the frequency of the filtered current signal to obtain the rotational speed frequency.

8. The vibration suppression device for a rotor in a magnetic bearing system according to claim 6, characterized in that: Also includes: The controller is configured to determine the original current instruction based on the second displacement signal and a preset reference displacement instruction.

9. A magnetic bearing system, characterized in that: A vibration suppression device for a rotor in a magnetic bearing system comprising the device described in any one of claims 6 to 8.

Images