Magnetic suspension bearing resonance interference elimination method and resonance interference elimination system

Abstract

The invention provides a magnetic suspension bearing resonance interference elimination method and a resonance interference elimination system, and aims to solve the problem of specific-frequency resonance interference caused by external interference excitation in static floating of a magnetic suspension bearing system. A PID double-closed-loop control structure is adopted, PID control is adopted for a displacement loop, an incomplete differential link is added, the dynamic characteristic and the robust performance of the system are effectively improved, a proportional resonance (PR) controller is introduced into a current PI closed loop, and by means of the infinite gain characteristic of the PR controller at the specific resonant frequency, the dynamic characteristic and the robust performance of the system are improved. The method is advantaged in that accurate and rapid compensation of specific frequency resonance interference is realized, rotor displacement and coil current signals are acquired and analyzed in real time, the harmonic frequency is determined, and the resonance interference inhibition effect is further improved through adjustment of PR controller parameters. The system is clear in structure, is simple to realize, does not need complex operation and extra sensor equipment, and has the prominent advantages of high real-time performance, excellent control performance and easiness in engineering realization.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic levitation, and particularly relates to a method for eliminating resonance interference of a magnetic levitation bearing, a system for eliminating resonance interference of a magnetic levitation bearing, and a non-transitory computer-readable storage medium. Background Art

[0002] Active magnetic levitation bearings have outstanding advantages such as no mechanical contact, no friction, no lubrication, and long service life, and are widely used in high-precision and high-speed rotating equipment. Due to manufacturing and assembly errors, the rotor inevitably has a certain degree of imbalance. When the magnetic levitation bearing is in the static floating state, due to external interferences such as sampling noise and sensor errors, specific-frequency resonance interference will occur during the floating process, and the current in the bearing winding will oscillate. If not processed, the closed-loop divergent system will eventually become unstable.

[0003] Currently, the control method of magnetic levitation bearings generally adopts pure PID (Proportional Integral Derivative) control. Although this method is simple to implement, its suppression effect on resonance interference of specific frequencies is limited.

[0004] In related technologies, magnetic levitation bearings usually use a notch filter to suppress specific-frequency resonance interference, that is, a notch filter is connected in series between the given signal of the displacement loop and the feedback of the actual position deviation to attenuate the component corresponding to the resonance frequency in the displacement signal, thereby reducing the intensity of the resonance frequency component in the output signal of the displacement loop. Since this method directly connects the notch filter in series in the closed-loop control loop, the closed-loop transfer function of the system is changed, affecting the overall dynamic characteristics and stability margin of the system. In addition, the differential term in the displacement-loop PID controller amplifies high-frequency noise, further weakening the effective suppression ability of the notch filter for the resonance frequency. When high-frequency resonance occurs during the actual operation of the system, the notch filter is difficult to achieve precise suppression, resulting in a significant reduction in the resonance suppression performance of the system and making it difficult to effectively improve the suspension control accuracy. Summary of the Invention

[0005] In order to solve the technical problem of specific-frequency resonance interference caused by external interference excitation during the static floating of the above magnetic levitation bearing system, the present invention provides a method for eliminating resonance interference of a magnetic levitation bearing.

[0006] The present invention also provides a system for eliminating resonance interference of a magnetic levitation bearing.

[0007] The present invention also provides a non-transitory computer-readable storage medium.

[0008] The technical solution adopted by the present invention is as follows:

[0009] An embodiment of the first aspect of the present invention provides a method for eliminating resonance interference of a magnetic levitation bearing, including the following steps: obtaining the actual displacement of the rotor of the magnetic levitation bearing in real time and the actual current signal, where the current signal includes the current signal in the X-axis direction and the current signal in the Y-axis direction ; inputting the actual displacement into the displacement loop, where the displacement loop adopts an incomplete differential PID and outputs a current set value ; obtaining the bias current , adding and subtracting the bias current and the current set value respectively for differential control to obtain a positive differential current and a negative differential current ; inputting the positive differential current , the negative differential current , the current signal in the X-axis direction , and the current signal in the Y-axis direction into the current loop, where the current loop is used to perform real-time FFT (Fast Fourier Transform) analysis on and to obtain the resonance frequency point , controlling a PR (Proportional-Resonant) controller to output a resonance compensation current according to the resonance frequency point , controlling a PI controller to output a PI current according to the positive differential current and the negative differential current , and outputting a comprehensive current according to the resonance compensation current and the PI current; applying the comprehensive current to the magnetic levitation bearing coil.

[0010] The method for eliminating resonance interference of the magnetic levitation bearing proposed above in the present invention also has the following additional technical features:

[0011] According to an embodiment of the present invention, the transfer function of the first-order low-pass filter link of the incomplete differential PID is: ; where is the time constant of the first-order low-pass filter, and s is the Laplace operator.

[0012] According to an embodiment of the present invention, controlling the PR controller to output a resonance compensation current according to the resonance frequency point specifically includes: outputting a current error of the PR controller based on the current signal in the X-axis direction , the current signal in the Y-axis direction and the given current value of the PR controller , where ; Input the PR controller current error into the PR controller, so that the PR controller outputs a resonant compensation current according to the PR controller current error and the resonant frequency point. Output a resonant compensation current.

[0013] According to an embodiment of the present invention, the transfer function of the PR controller is as follows: ; where is the resonant frequency point, is the proportional gain of the PR controller, is the resonant coefficient, and s is the Laplace operator.

[0014] An embodiment of the second aspect of the present invention provides a magnetic levitation bearing resonant interference cancellation system, including: a sampling module for real-time acquisition of the actual displacement and the actual current signal of the magnetic levitation bearing rotor. The current signal includes the X-axis direction current signal and the Y-axis direction current signal ; a displacement loop for using an incomplete differential PID to output a current set value ; a differential module for obtaining a bias current , performing differential control by adding and subtracting the bias current and the current set value respectively to obtain a positive differential current and a negative differential current ; a current loop for performing FFT real-time analysis on and to obtain the resonant frequency point , controlling the PR controller to output a resonant compensation current according to the resonant frequency point , controlling the PI controller to output a PI current according to the positive differential current and the negative differential current , and outputting a combined current according to the resonant compensation current and the PI current; an application module for applying the combined current to the magnetic levitation bearing coil.

[0015] The above magnetic levitation bearing resonant interference cancellation system of the present invention further has the following additional technical features:

[0016] According to an embodiment of the present invention, the transfer function of the first-order low-pass filter link of the incomplete differential PID is: ; where is the time constant of the first-order low-pass filter, and s is the Laplace operator.

[0017] According to an embodiment of the present invention, the current loop is specifically used for: based on the X-axis direction current signal The Y-axis direction current signal and the given current value of the PR controller Output the current error of the PR controller, where ; input the current error of the PR controller into the PR controller, so that the PR controller outputs a resonant compensation current according to the current error of the PR controller and the resonant frequency point Output the resonant compensation current

[0018] According to an embodiment of the present invention, the transfer function of the PR controller is as follows ; where is the resonant frequency point is the proportional gain of the PR controller is the resonant coefficient, and s is the Laplace operator

[0019] An embodiment of the third aspect of the present invention proposes a non-transitory computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, it implements the magnetic levitation bearing resonant interference cancellation method described in the first aspect embodiment of the present invention

[0020] The present invention has the following beneficial effects

[0021] The present invention adopts a PID double closed-loop control structure. The displacement loop adopts PID control and adds an incomplete differential link, which effectively improves the dynamic characteristics and robustness of the system. A proportional resonance (PR) controller is introduced into the current PI closed-loop. Utilizing the infinite gain characteristic of the PR controller at a specific resonant frequency, it realizes precise and rapid compensation for specific frequency resonant interference. By real-time collecting and analyzing the rotor displacement and coil current signals, the harmonic frequency is determined, and by adjusting the PR controller parameters, the resonant interference suppression effect is further improved

[0022] The structure of the present invention is clear and easy to implement. Without complex operations and additional sensor devices, it can significantly improve the control accuracy and system stability of the magnetic levitation bearing, and has the outstanding advantages of strong real-time performance, excellent control performance, and easy engineering implementation

[0023] The present invention does not directly connect a frequency-selective element in the main control loop, so it avoids the problem of changing the system closed-loop characteristics caused by the notch filter connected in series in the closed-loop control structure, thus not having a negative impact on the overall dynamic characteristics of the system, and ensuring the stability and dynamic response speed of the closed-loop control system BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a flowchart of a magnetic levitation bearing resonant interference cancellation method according to an embodiment of the present invention

[0025] Figure 2 Schematic diagram of the principle of the displacement loop according to an embodiment of the present invention;

[0026] Figure 3 Schematic diagram of the principle of the method for eliminating resonance interference of a magnetic levitation bearing according to an embodiment of the present invention;

[0027] Figure 4 Block diagram of the system for eliminating resonance interference of a magnetic levitation bearing according to an embodiment of the present invention. Detailed implementation manners

[0028] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0029] Next, the method for eliminating resonance interference of a magnetic levitation bearing, the system for eliminating resonance interference of a magnetic levitation bearing, and a non - temporary computer - readable storage medium proposed in the embodiments of the present invention will be described in conjunction with the accompanying drawings.

[0030] Figure 1 Flowchart of the method for eliminating resonance interference of a magnetic levitation bearing according to an embodiment of the present invention. As Figure 1 shown, the method includes the following steps:

[0031] S1, obtain the actual displacement of the rotor of the magnetic levitation bearing and the actual current signal in real time. The current signal includes the current signal in the X - axis direction and the current signal in the Y - axis direction .

[0032] Specifically, the actual displacements of the rotor in the X - axis and Y - axis directions are obtained in real time through a magnetic levitation bearing displacement sensor , and the current feedback signal in the magnetic levitation bearing coil is collected in real time. The real - time sampling of the signal is completed through the analog - to - digital conversion module in the digital signal processor to obtain the current signal in the X - axis direction and the current signal in the Y - axis direction .

[0033] S2, input the actual displacement into the displacement loop. The displacement loop adopts an incomplete differential PID and outputs a current set value .

[0034] Specifically, the displacement loop adopts the PID control principle. As Figure 2 shown, the displacement loop takes the actual displacement of the rotor The deviation from the target displacement x_ref is used as the input, and through PID control, a corresponding control current command is generated to achieve stable suspension of the rotor. PID includes a proportional link, an integral link, and a differential link. The proportional time constant is 1, the integral time constant is 1 / s, and the differential time constant is , the proportional coefficient is kp, the integral coefficient is ki, and the differential coefficient is kd. The differential link does not adopt a pure differential form but an incomplete differential, that is, a first-order low-pass filtering process is performed on the differential term to avoid the amplification effect of the differential link on high-frequency noise.

[0035] In one embodiment of the present invention, the transfer function of the first-order low-pass filtering link of the incomplete differential PID is:

[0036] ;

[0037] wherein, is the time constant of the first-order low-pass filter, and s is the Laplace operator. By reasonably adjusting the time constant , the high-frequency noise interference in the displacement signal can be effectively suppressed, and the control stability and accuracy of the displacement signal can be improved.

[0038] S3. Obtain the bias current , and perform differential control by adding and subtracting the bias current and the current set value respectively to obtain the positive differential current and the negative differential current .

[0039] Specifically, the current command signal output by the displacement loop needs to enter the current loop closed-loop control through the differential current control method, that is, the current set value output by the displacement loop and the preset bias current are respectively superimposed and subtracted to generate a differential current between the relative coils, thereby generating a differential current control signal between the relative coils, that is, the positive differential current and the negative differential current , so as to form an accurate differential electromagnetic force and effectively control the rotor to achieve precise suspension positioning in the X-axis and Y-axis directions respectively.

[0040] S4. Input the positive differential current , the negative differential current , the current signal in the X-axis direction , and the current signal in the Y-axis direction into the current loop. The current loop is used to perform FFT real-time analysis on and to obtain the resonant frequency point , and control the PR controller according to the resonant frequency point Output the resonant compensation current, and control the PI controller according to the positive differential current and the negative differential current Output the PI current, and output the combined current according to the resonant compensation current and the PI current.

[0041] Specifically, in the actual operation process of the magnetic levitation bearing system, resonance interference of a specific frequency will occur, resulting in a decrease in the operation accuracy of the system. To effectively eliminate this resonant frequency, in this embodiment, a proportional resonance (PR) controller is introduced into the current loop. The tracking effect of the PR controller on the fixed-frequency AC signal is much better than that of the PI controller.

[0042] In an embodiment of the present invention, control the PR controller to output the resonant compensation current according to the resonant frequency point Specifically, it includes: based on the current signal in the X-axis direction and the current signal in the Y-axis direction and the given current value of the PR controller Output the current error of the PR controller, where ; input the current error of the PR controller into the PR controller, so that the PR controller outputs the resonant compensation current according to the current error of the PR controller and the resonant frequency point Output the resonant compensation current.

[0043] As a specific example, the transfer function of the PR controller is:

[0044] ;

[0045] where is the resonant frequency point, is the proportional gain of the PR controller, is the resonant coefficient, and s is the Laplace operator.

[0046] Specifically, as shown in Figure 3 , send the above positive differential current and the negative differential current to the PI controller in the current loop. The PI controller performs PI operation according to the differential current and outputs the PI current. At the same time, the current loop pairs and Similarly, in the DSP (Digital Signal Processing), use the FFT library function to analyze the spectrum information in real time, and determine the frequency with a significantly higher amplitude than other frequency components in the spectrum through the amplitude comparison method, which is the resonant frequency point in the real-time operation process of the magnetic levitation bearing system, and this resonant frequency point It is provided to the PR controller in real time as the real-time adjustment input of the PR controller parameters. The PR controller is based on the current signal in the X-axis direction , the current signal in the Y-axis direction respectively makes a difference with the given current value of the PR controller and outputs the current error of the PR controller. Among them, , the PR controller outputs the resonant compensation current according to the current error of the PR controller and the resonant frequency point . The resonant compensation current is superimposed with the PI current to form a combined current.

[0047] Thus, in the current loop, the PI controller is used for current tracking, and the PR controller can accurately suppress the resonant interference of specific frequencies.

[0048] S5, apply the combined current to the magnetic levitation bearing coil.

[0049] Specifically, as Figure 3 shown, through the PWM (Pulse Width Modulation) modulation module built in the DSP processor, calculate the corresponding PWM duty cycle according to the combined current, and drive the on and off of the switching tubes of the inverter through PWM modulation, so as to accurately control the actual drive current of the magnetic levitation AMB (Active Magnetic Bearing) coil, realize the high-precision stable suspension of the rotor at the command position, and eliminate the resonant interference of specific frequencies in real time.

[0050] The whole control principle can be seen in Figure 3 shown.

[0051] According to the method for eliminating resonant interference of a magnetic levitation bearing according to an embodiment of the present invention, a PID double closed-loop control structure is adopted. The displacement loop adopts PID control and adds an incomplete differential link, which effectively improves the dynamic characteristics and robustness of the system. A proportional resonance (PR) controller is introduced into the current PI closed-loop. Utilizing the infinite gain characteristic of the PR controller at a specific resonant frequency, accurate and rapid compensation for resonant interference of specific frequencies is realized. By real-time collecting and analyzing the rotor displacement and coil current signals, the harmonic frequency is determined, and by adjusting the parameters of the PR controller, the effect of suppressing resonant interference is further improved. The structure of the present invention is clear and simple to implement. Without complex operations and additional sensor devices, the control accuracy and system stability of the magnetic levitation bearing can be significantly improved. It has the outstanding advantages of strong real-time performance, excellent control performance, and easy engineering implementation. The present invention does not directly connect frequency-selective elements in the main control loop, so it avoids the problem of changing the closed-loop characteristics of the system caused by the series connection of notch filters in the closed-loop control structure, thus not having a negative impact on the overall dynamic characteristics of the system and ensuring the stability and dynamic response speed of the closed-loop control system.

[0052] Corresponding to the above method for eliminating the resonance interference of the magnetic levitation bearing, the present invention also provides a system for eliminating the resonance interference of the magnetic levitation bearing. Since the system embodiment of the present invention corresponds to the above method embodiment, for the details not disclosed in the system embodiment, reference may be made to the above method embodiment, and no further elaboration will be provided in the present invention.

[0053] Figure 4 is a schematic block diagram of a system for eliminating the resonance interference of a magnetic levitation bearing according to an embodiment of the present invention, as Figure 4 shown, the system includes: a sampling module 1, a displacement loop 2, a differential module 3, a current loop 4, and an application module 5.

[0054] The sampling module 1 is configured to obtain the actual displacement of the rotor of the magnetic levitation bearing in real time and the actual current signal, and the current signal includes the current signal in the X-axis direction and the current signal in the Y-axis direction ; the displacement loop 2 is configured to use an incomplete differential PID to output a current set value ; the differential module 3 is configured to obtain a bias current , perform differential control by adding and subtracting the bias current and the current set value respectively to obtain a positive differential current and a negative differential current ; the current loop 4 is configured to perform real-time FFT analysis on and to obtain a resonance frequency point , control the PR controller to output a resonance compensation current according to the resonance frequency point , control the PI controller to output a PI current according to the positive differential current and the negative differential current , and output a comprehensive current according to the resonance compensation current and the PI current; the application module 5 is configured to apply the comprehensive current to the magnetic levitation bearing coil.

[0055] According to an embodiment of the present invention, the transfer function of the first-order low-pass filter link of the incomplete differential PID is: ; where is the time constant of the first-order low-pass filter, and s is the Laplace operator.

[0056] According to an embodiment of the present invention, the current loop is specifically configured to: output a PR controller current error based on the current signal in the X-axis direction , the current signal in the Y-axis direction and the given current value of the PR controller , where ; Input the PR controller current error into the PR controller so that the PR controller can output a resonant compensation current according to the PR controller current error and the resonant frequency point. Output the resonant compensation current.

[0057] According to an embodiment of the present invention, the transfer function of the PR controller is as follows: ; where is the resonant frequency point, is the proportional gain of the PR controller, is the resonance coefficient, and s is the Laplace operator.

[0058] The resonant interference cancellation system of the magnetic levitation bearing according to the embodiment of the present invention adopts a PID double closed-loop control structure. The displacement loop adopts PID control and adds an incomplete differential link, effectively improving the dynamic characteristics and robustness of the system. A proportional resonance (PR) controller is introduced into the current PI closed-loop. Utilizing the infinite gain characteristic of the PR controller at a specific resonant frequency, precise and rapid compensation for specific frequency resonant interference is achieved. By real-time collecting and analyzing the rotor displacement and coil current signals, the harmonic frequency is determined, and by adjusting the PR controller parameters, the resonant interference suppression effect is further improved. The structure of the present invention is clear and easy to implement. Without complex operations and additional sensor devices, the control accuracy and system stability of the magnetic levitation bearing can be significantly improved, and it has the outstanding advantages of strong real-time performance, excellent control performance, and easy engineering implementation. The present invention does not directly connect frequency-selective elements in the main control loop, thus avoiding the problem of system closed-loop characteristic change caused by the notch filter connected in series in the closed-loop control structure, and will not have a negative impact on the overall dynamic characteristics of the system, ensuring the stability and dynamic response speed of the closed-loop control system.

[0059] In addition, the present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, the above-mentioned method for canceling resonant interference of the magnetic levitation bearing is implemented.

[0060] According to the non-transitory computer-readable storage medium of the embodiment of the present invention, when the computer program stored thereon is executed by a processor, the actual displacement of the rotor of the magnetic levitation bearing is obtained in real time and the actual current signal. The current signal includes the current signal in the X-axis direction and the current signal in the Y-axis direction . The actual displacement is input into the displacement loop. The displacement loop adopts incomplete differential PID and outputs the current set value . The bias current is obtained . The bias current and the current set value are respectively added and subtracted for differential control to obtain the positive differential current and negative differential current , the positive differential current , negative differential current , current signal in the X-axis direction , in the Y-axis direction input current loop, the current loop is used to and perform FFT real-time analysis to obtain the resonant frequency point , control the PR controller to output the resonant compensation current according to the resonant frequency point , control the PI controller to output the PI current according to the positive differential current and negative differential current Output the combined current according to the resonant compensation current and the PI current, and apply the combined current to the magnetic bearing coil. Thus, a PID double closed-loop control structure is adopted. The displacement loop adopts PID control and adds an incomplete differential link, effectively improving the dynamic characteristics and robustness of the system. A proportional resonance (PR) controller is introduced into the current PI closed-loop. Utilizing the infinite gain characteristic of the PR controller at a specific resonant frequency, precise and rapid compensation for specific frequency resonance interference is achieved. By real-time collecting and analyzing the rotor displacement and coil current signals, the harmonic frequency is determined, and by adjusting the parameters of the PR controller, the resonance interference suppression effect is further improved.

[0061] In the description of the present invention, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. The meaning of "a plurality" is two or more, unless otherwise specifically defined.

[0062] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not have to be directed to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0063] Any process or method description represented in a flowchart or otherwise described herein can be understood to represent a module, segment, or portion of code including one or more executable instructions for implementing a customized logic function or process, and the scope of the preferred embodiments of the present invention includes additional implementations where functions may be executed not in the order shown or discussed, including in a substantially simultaneous manner according to the functions involved or in a reverse order, which should be understood by those skilled in the art to which the embodiments of the present invention pertain.

[0064] The logic and / or steps represented in a flowchart or otherwise described herein, for example, can be considered a sequenced list of executable instructions for implementing a logical function, and can be embodied specifically in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, a system including a processor, or other systems that can fetch and execute instructions from the instruction execution system, apparatus, or device. As used in this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable medium include the following: an electrical connection having one or more wires (electronic device), a portable computer diskette (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium can even be paper or other suitable medium on which the program can be printed, as the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpretation, or otherwise processing as appropriate, and then storing it in a computer memory.

[0065] It should be understood that various parts of the present invention can be implemented by hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any one or a combination of the following techniques well known in the art can be used: discrete logic circuits having logic gate circuits for implementing logical functions on data signals, application specific integrated circuits having appropriate combinational logic gate circuits, programmable gate arrays (PGAs), field programmable gate arrays (FPGAs), and the like.

[0066] Those of ordinary skill in the art can understand that all or part of the steps carried out in implementing the above-described embodiment methods can be completed by instructing relevant hardware through a program. The said program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiment.

[0067] In addition, in each of the embodiments of the present invention, the functional units can be integrated into a processing module, or each unit can exist physically alone, or two or more units can be integrated into one module. The above-mentioned integrated module can be implemented in the form of hardware or in the form of a software functional module. When the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0068] The above-mentioned storage medium can be a read-only memory, a magnetic disk, an optical disc, etc.

[0069] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for eliminating resonance interference of a magnetic levitation bearing, characterized in that, Including the following steps: Obtain the actual displacement of the rotor of the magnetic levitation bearing in real time and the actual current signal, where the current signal includes the current signal in the X-axis direction and the current signal in the Y-axis direction ; The actual displacement is input into the displacement loop, and the displacement loop adopts an imperfect differential PID to output the current set value ; Obtain the bias current , and perform differential control by adding and subtracting the bias current and the current set value respectively to obtain the positive differential current and the negative differential current ; The positive differential current , the negative differential current , the current signal in the X-axis direction , the input current loop, which is used to and perform FFT real-time analysis to obtain the resonant frequency point , control the PR controller to output the resonant compensation current according to the resonant frequency point , control the PI controller to output the PI current according to the positive differential current and the negative differential current , and output the comprehensive current according to the resonant compensation current and the PI current; Applying the synthesized current to the magnetic levitation bearing coil.

2. The method for eliminating resonance interference of a magnetic levitation bearing according to claim 1, wherein The transfer function of the first-order low-pass filtering link of the incomplete differential PID is as follows: ； wherein, is the time constant of the first-order low-pass filter, and s is the Laplace operator.

3. The method for eliminating resonance interference of a magnetic levitation bearing according to claim 1, characterized in that The control PR controller is based on the resonant frequency point Output the resonant compensation current, specifically including: According to the current signal in the X-axis direction , the current signal in the Y-axis direction and the given current value of the PR controller output the current error of the PR controller, where ; Input the PR controller current error into the PR controller, so that the PR controller outputs a resonant compensation current according to the PR controller current error and the resonant frequency point ​ 4. The method for eliminating resonance interference of the magnetic levitation bearing according to claim 3, characterized in that The transfer function of the PR controller is as follows: ； Among them, is the resonant frequency point, is the proportional gain of the PR controller, is the resonance coefficient, and s is the Laplace operator.

5. A magnetic levitation bearing resonance interference elimination system, characterized in that Including: A sampling module, which is used to obtain the actual displacement of the rotor of the magnetic levitation bearing in real time and the actual current signal, where the current signal includes the current signal in the X-axis direction and the current signal in the Y-axis direction ; A displacement loop, which is used to adopt an incomplete differential PID to output a current set value ; Differential module, which is used to obtain a bias current , and perform differential control by adding and subtracting the bias current and the current set value respectively, to obtain a positive differential current and a negative differential current ; Current loop, the current loop is used to and perform FFT real-time analysis to obtain the resonant frequency point , control the PR controller to output the resonant compensation current according to the resonant frequency point , control the PI controller to output the PI current according to the positive differential current and the negative differential current output the comprehensive current according to the resonant compensation current and the PI current; An application module for applying the synthesized current to the magnetic levitation bearing coil.

6. The magnetic levitation bearing resonance interference elimination system according to claim 5, wherein The transfer function of the first-order low-pass filtering link of the incomplete differential PID is as follows: ； wherein, is the time constant of the first-order low-pass filter, and s is the Laplace operator.

7. The magnetic levitation bearing resonance interference elimination system according to claim 5, wherein The current loop is specifically used for: According to the current signal in the X-axis direction , the current signal in the Y-axis direction and the given current value of the PR controller output the current error of the PR controller, where ; Input the PR controller current error into the PR controller, so that the PR controller outputs a resonant compensation current according to the PR controller current error and the resonant frequency point Output a resonant compensation current.

8. The magnetic levitation bearing resonance interference elimination system according to claim 7, wherein The transfer function of the PR controller is: ； Among them, is the resonant frequency point, is the proportional gain of the PR controller, is the resonance coefficient, and s is the Laplace operator.

9. A non-transitory computer-readable storage medium, characterized in that, A computer program is stored thereon, and when the program is executed by a processor, it implements the method for eliminating resonance interference of a magnetic levitation bearing according to any one of claims 1-4.

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