Active magnetic suspension bearing damping device and method for damping hydroelectric generating set

Abstract

The invention belongs to the technical field of hydroelectric power generation equipment and electromagnetic control, and particularly relates to an active magnetic suspension bearing vibration reduction device and method for vibration reduction of a hydroelectric generating set. The device comprises a displacement sensor, a control system, a power amplifier, a radial magnetic bearing, an axial magnetic bearing and a high-speed motor, the rotor offset and the vibration signal are detected in real time through the sensor, the controller calculates output based on PID, fuzzy control or a self-adaptive algorithm, dynamic adjustable magnetic force is formed by adjusting the current of the excitation winding, rigidity and damping regulation and control are achieved, and therefore vibration of the hydroelectric generating set is restrained.

Description

Technical Field

[0001] This invention belongs to the field of hydropower equipment and electromagnetic control technology, specifically relating to an active magnetic levitation bearing vibration reduction device and method for hydropower unit vibration reduction. Background Technology

[0002] During long-term operation, hydro-generator units often experience significant vibrations due to factors such as water flow pulsation, hydraulic instability, shaft imbalance, and electromagnetic disturbances. These vibrations not only affect the stability and efficiency of the unit but also exacerbate bearing wear, shorten rotor life, and even lead to unit failure. While existing sliding and rolling bearings are commonly used, their vibration damping capabilities are limited, and they present issues related to friction, wear, and lubrication maintenance. Hydrodynamic / hydrostatic bearings can improve vibration to some extent, but their systems are complex and costly. Magnetic levitation bearings have been applied in fields such as high-speed motors, but their direct application in hydro-generator units faces challenges in terms of control stability and disturbance rejection under strong hydraulic pulsation environments. Therefore, a novel magnetic levitation bearing solution is urgently needed that can actively suppress vibration, improve unit stability, and reduce maintenance costs. Summary of the Invention

[0003] To address the problems existing in the prior art, this invention provides an active magnetic levitation bearing vibration reduction device and method for hydropower unit vibration reduction. The aim is to achieve adaptive vibration reduction through active adjustment of electromagnetic force, effectively reducing the vibration amplitude during the operation of the hydropower unit and improving its operational stability and reliability.

[0004] To achieve the above objectives, the present invention provides the following solution: An active magnetic levitation bearing vibration reduction device for hydroelectric generator sets, the device comprising: a displacement sensor, a control system, a power amplifier, a radial magnetic bearing, an axial magnetic bearing, and a high-speed motor; The displacement sensor is used to detect the radial displacement of the rotor assembly in real time. The control system is used to generate a position offset error based on the difference between a preset displacement command and a feedback signal, and to obtain an excitation current command. The power amplifier is connected to the control system and is used to amplify the excitation current command to drive the excitation winding of the radial magnetic bearing and form a controllable magnetic force in the air gap. The radial magnetic bearing is used to generate radial support force. The stator assembly constitutes the stator part of the radial magnetic bearing. The stator assembly includes an annular stator core with a stacked silicon steel sheet structure and a uniformly distributed excitation winding. The stator core is coaxially sleeved and fixed in the unit frame. A radial working air gap is formed between its inner circular surface and the magnetic sleeve on the rotor assembly. The excitation winding is wound in the pole teeth or slots of the stator core, uniformly distributed along the circumferential direction, and radially facing the rotor magnetic sleeve, so as to form a radial magnetic bearing together with the rotor assembly. The axial magnetic bearing is used to achieve axial positioning and balance; The high-speed motor is used to drive the rotor to rotate.

[0005] Preferably, the radial displacement signal of the rotor detected in real time by the displacement sensor is filtered and amplified to obtain a feedback signal that is input to the control system. The filtering and amplification module includes a low-noise differential amplifier circuit and a filtering stage: An instrumentation amplifier is used to amplify the signal. Noise and interference are removed by using Butterworth low-pass or band-pass filter circuits and DSP internal digital filtering algorithms.

[0006] Preferably, the control system calculates the excitation current command by integrating adaptive PID control, an adaptive notch filter based on the LMS algorithm, and feedforward compensation control. An adaptive PID algorithm is used as the main control loop, with the rotor radial position offset error as the input, and the PID excitation current is calculated in real time. Based on the stability of PID control, an adaptive notch filter based on LMS algorithm is used to identify and suppress narrowband periodic vibrations caused by hydraulic pulsation, blade frequency and electromagnetic imbalance, and to calculate the excitation compensation current. When the external disturbance signal of turbine operating parameters or flow pulsation is measurable, a feedforward compensation mechanism is introduced to construct a mathematical model of disturbance and displacement response and generate a canceling current that is opposite in phase to the disturbance. The final excitation current command is obtained based on the PID excitation current, excitation compensation current, and cancellation current.

[0007] Preferably, the adaptive notch filter can automatically track and lock onto specific frequency vibration components caused by hydraulic pulsation or electromagnetic imbalance, and generate a control signal with equal amplitude but opposite phase to cancel them out.

[0008] Preferably, the device further includes a protective bearing, installed on the outside or end of the rotor, and made of composite ceramic or polymer wear-resistant material; When the control system malfunctions or fails due to power failure, the protective bearings step in to bear the rotor load and ensure the safe operation of the unit.

[0009] The present invention also provides a method for vibration reduction of an active magnetic levitation bearing for hydroelectric generator units, the method being implemented using the aforementioned device, the method comprising: The radial displacement signal of the rotor is detected in real time by a displacement sensor. The radial displacement signal of the rotor is amplified and filtered by a signal conditioning circuit to obtain a feedback signal that is input to the control system. The control system generates a position offset error based on the difference between the preset displacement command and the feedback signal, and calculates the excitation current command through adaptive PID control, LMS notch filtering and feedforward compensation algorithm. The excitation current command is amplified by the power amplifier and drives the excitation winding of the radial magnetic bearing to form a controllable magnetic force in the air gap, thereby realizing active control of the rotor position and vibration. The rotor radial displacement signal detected in real time by the displacement sensor is used as feedback input to achieve closed-loop stable regulation of vibration reduction in the hydropower unit.

[0010] Preferably, the method of detecting the radial displacement signal of the rotor in real time using a displacement sensor, and obtaining a feedback signal input to the control system after amplification and filtering of the radial displacement signal by a signal conditioning circuit includes: The radial displacement signal of the rotor detected in real time by the displacement sensor is filtered and amplified to obtain a feedback signal that is input to the control system. The filtering and amplification module includes a low-noise differential amplifier circuit and a filtering stage: An instrumentation amplifier is used to amplify the signal. Noise and interference are removed by using Butterworth low-pass or band-pass filter circuits and DSP internal digital filtering algorithms.

[0011] Preferably, the method by which the control system generates a position offset error based on the difference between a preset displacement command and a feedback signal, and calculates the excitation current command through adaptive PID control, LMS notch filtering, and feedforward compensation algorithm includes: An adaptive PID algorithm is used as the main control loop, with the rotor radial position offset error as the input, and the PID excitation current is calculated in real time. Based on the stability of PID control, an adaptive notch filter based on LMS algorithm is used to identify and suppress narrowband periodic vibrations caused by hydraulic pulsation, blade frequency and electromagnetic imbalance, and to calculate the excitation compensation current. When the external disturbance signal of turbine operating parameters or flow pulsation is measurable, a feedforward compensation mechanism is introduced to construct a mathematical model of disturbance and displacement response and generate a canceling current that is opposite in phase to the disturbance. The final excitation current command is obtained based on the PID excitation current, excitation compensation current, and cancellation current.

[0012] Preferably, the adaptive notch filter can automatically track and lock onto specific frequency vibration components caused by hydraulic pulsation or electromagnetic imbalance, and generate a control signal with equal amplitude but opposite phase to cancel them out.

[0013] Preferably, the method further includes, in the event of an abnormality or power failure in the control system, using a protective bearing made of composite ceramic or polymer wear-resistant material to bear the rotor load and ensure safe operation of the unit.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Through feedforward and adaptive notch control, it is possible to directly cancel the force at the source of specific vibration sources of the water turbine (such as rotational frequency, blade frequency, and vortex frequency), which greatly reduces the vibration amplitude and is far superior to passive vibration reduction. 2. Adaptive control adapts to different operating conditions, achieving smooth operation throughout the entire process from start-up to shutdown; 3. Composite protective bearings ensure safety under partial system failures or extreme operating conditions; 4. Non-contact operation eliminates mechanical friction loss, saves on complex oil lubrication systems, and reduces operation and maintenance costs. Attached Figure Description

[0015] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments are briefly introduced below. 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 effort.

[0016] Figure 1 This is a schematic diagram of the magnetic levitation bearing vibration reduction device module according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the rotating shaft structure according to an embodiment of the present invention. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] Example 1 like Figure 1 , Figure 2 As shown, the present invention provides an active magnetic levitation bearing vibration reduction device for hydroelectric generator units, comprising: a displacement sensor, a control system, a power amplifier, a radial magnetic bearing, an axial magnetic bearing, and a high-speed motor; The displacement sensor is used to detect the radial displacement of the rotor assembly in real time. The control system is used to generate a position offset error based on the difference between the displacement command and the feedback signal, and to obtain the excitation current command. The power amplifier is connected to the control system and is used to amplify the excitation current command to drive the excitation winding of the radial magnetic bearing and form a controllable magnetic force in the air gap. The radial magnetic bearing is used to generate radial support force. The stator assembly constitutes the stator part of the radial magnetic bearing. The stator assembly includes an annular stator core with a stacked silicon steel sheet structure and a uniformly distributed excitation winding. The stator core is coaxially sleeved and fixed in the unit frame. A radial working air gap is formed between its inner circular surface and the magnetic sleeve on the rotor assembly. The excitation winding is wound in the pole teeth or slots of the stator core, uniformly distributed along the circumferential direction, and radially facing the rotor magnetic sleeve, so as to form a radial magnetic bearing together with the rotor assembly. The axial magnetic bearing is used to achieve axial positioning and balance; The high-speed motor is used to drive the rotor to rotate.

[0020] The device of the present invention achieves active magnetic force adjustment and vibration reduction support through closed-loop control. The specific implementation process is as follows: The stator assembly in the radial magnetic bearing includes a stator core with a stacked silicon steel sheet structure and uniformly distributed excitation windings. The excitation windings are evenly distributed radially on the inner wall of the stator. By adjusting the excitation current, a radially controllable magnetic field is generated to provide non-contact support force and damping adjustment capability for the rotor. The rotor assembly is set on the outer periphery of the unit's shaft and includes a magnetic sleeve made of high magnetic permeability material. It is installed concentrically with the main shaft of the hydropower unit. The outer surface of the magnetic sleeve is a smooth cylinder, which is used to generate a magnetic field interaction with the stator.

[0021] The specific connection method is as follows: A displacement sensor detects the rotor radial displacement signal in real time. The rotor radial displacement signal is amplified and filtered by a signal conditioning circuit to obtain a feedback signal (i.e., the collected rotor displacement signal), which is then input to the control system. The control system generates a position offset error based on the difference between the preset displacement command (e.g., the rotor's position at the geometric center of the magnetic bearing as the target displacement command) and the feedback signal. This error is then used to calculate the excitation current command through adaptive PID control, LMS notch filtering, and feedforward compensation algorithms. The excitation current command is amplified by a power amplifier and drives the excitation winding of the radial magnetic bearing, forming a controllable magnetic force in the air gap to achieve active control of the rotor position and vibration. On the other hand, the aforementioned rotor displacement feedback signal after signal conditioning is used to form a position closed loop to achieve stable adjustment of the rotor position.

[0022] Structurally, the shaft has a total length of 647.5 mm, consisting of a water pump interface section (142 mm) and a magnetic levitation bearing motor section (505.5 mm). Within the magnetic levitation bearing motor section, the following axial sequence is arranged: radial magnetic bearing—high-speed motor—radial magnetic bearing—axial sensor detection area—protective bearing—rotary transformer. The radial magnetic bearings are located at both ends of the high-speed motor to generate radial support force; the axial magnetic bearing is located at the tail end of the shaft to achieve axial positioning and balance; the protective bearing is located outside the magnetic bearings and intervenes to provide support when the control system is powered off or malfunctions (e.g., the magnetic levitation bearing cannot levitate properly), preventing direct contact between the rotor and stator; the axial sensor detection area measures the axial displacement of the rotor; and the rotary transformer measures the speed and position of the high-speed motor. The high-speed motor is installed between the two sets of radial magnetic bearings, effectively reducing eccentric torque and vibration coupling.

[0023] Specifically, the displacement sensor of the present invention is an eddy current displacement sensor, which can detect the micron-level displacement of the rotor relative to the stator. The present invention also includes an acceleration sensor for measuring broadband vibration signals.

[0024] Eddy current displacement sensors and accelerometers are arranged in the X and Y radial directions, respectively, to detect the micron-level displacement of the rotor relative to the stator and broadband vibration signals in real time. The rotor's displacement and vibration signals are acquired in real time by the eddy current displacement sensors and accelerometers, and the acquired signals are input into the control system for calculation after being filtered and amplified by the modules.

[0025] The filtering and amplification module includes a low-noise differential amplifier circuit and a filtering stage to ensure the stability and accuracy of the acquired signal. An instrumentation amplifier is used to amplify the signal. Noise and interference are removed by using Butterworth low-pass or band-pass filter circuits and DSP internal digital filtering algorithms.

[0026] Furthermore, the control system uses a digital signal processor (DSP) or a field-programmable gate array (FPGA) to achieve high-speed signal processing and control operations. By integrating adaptive PID control, an adaptive notch filter based on the LMS algorithm, and feedforward compensation control, it calculates the excitation current command to actively suppress unit vibration. In the control layer, an adaptive PID algorithm is used as the main control link, with the rotor radial position offset error as the input, and the PID excitation current is calculated in real time. ; ; in, x ref ( t () represents a displacement command. i PID (t ) represents the PID excitation current. These are proportional, integral, and differential gains, respectively. e ( t The error is the position offset. The displacement signal of the rotor is collected; To suppress measurement noise, a first-order filter is used in the derivative term to keep the rotor centered and suspended, and to provide necessary electromagnetic damping. The PID parameters can be automatically adjusted according to the unit's operating conditions (such as load, speed, and vibration amplitude), enabling the control system to have good stability and response speed under different operating conditions.

[0027] Based on the stability of PID control, an adaptive notch filter based on the LMS algorithm is used to identify and suppress narrowband periodic vibrations caused by hydraulic pulsation, blade frequency and electromagnetic imbalance, and to calculate the excitation compensation current.

[0028] An adaptive notch filter extracts the characteristic vibration frequencies of the vibration signal in real time. Within the control system, it uses a Fast Fourier Transform to identify the characteristic vibration frequencies of the main vibration components and generates a sinusoidal control signal with the same frequency but opposite phase. The control system then calculates the corresponding excitation compensation current based on the amplitude of this sinusoidal control signal. This causes the generated electromagnetic force to superimpose in the opposite direction to the disturbance force in time, thereby canceling out the vibration component of the characteristic vibration frequency.

[0029] The LMS algorithm uses the following weight update formula: ; in, For the first n The sampling time of the first sampling moment i Individual weight coefficients, This is the step size factor (learning rate). This represents the vibration control error signal at that moment. The reference signal or orthogonal basis function (e.g., sine and cosine components) is related to the target vibration frequency. n For discrete time sequence numbers. i This is the filter weight index.

[0030] It enables online learning and self-adjustment, allowing the control system to maintain its vibration reduction effect even when operating conditions change or frequency drifts.

[0031] At this point, when the external disturbance signal of the turbine operating parameters or flow pulsation is measurable, a feedforward compensation mechanism is introduced to construct a mathematical model of the disturbance and displacement response and generate a canceling current that is opposite in phase to the disturbance.

[0032] By establishing a mathematical model of disturbance and displacement response, the control system can respond to external disturbance signals. Predict the rotor response pattern.

[0033] The model building process includes three stages: data acquisition, signal preprocessing, and parameter identification. Rotor displacement signals are acquired under steady-state operation. External disturbance signals After filtering, amplification, and decoupling, the signal is input to the control system. The controller uses the least squares method to establish linear dynamic equations: ; in, , , For equivalent mass, damping, and stiffness, This is the gain coefficient of electromagnetic force on excitation current.

[0034] Based on frequency domain analysis, the disturbance transfer function and control transfer function can be further obtained: Perturbation transfer function: ; in, X ( s ) represents the displacement signal. D ( s ) indicates an external disturbance signal.

[0035] Control transfer function: , in, I ( s ) represents a current signal.

[0036] This leads to the determination of the feedforward compensation channel, which is used to generate a compensation current signal that is out of phase with the disturbance, thereby achieving active cancellation of predictable disturbances. ; By generating a canceling current in advance through feedforward compensation control, the predictable disturbance can be actively suppressed. .

[0037] Finally, the PID excitation current, excitation compensation current, and cancellation current are weighted and fused to obtain the final excitation current command.

[0038] The weighted fusion process is completed by the signal distribution module inside the control system. First, the weights are dynamically calculated based on the real-time performance indicators of each control element (such as error magnitude and vibration amplitude). , , and keep When the control system deviation is large, the weight of the PID loop is increased to ensure rapid stabilization; when vibration at a specific frequency is detected, the weight of the LMS loop is automatically increased to enhance the vibration suppression effect; if the external disturbance is predictable and reliable, the weight of the feedforward loop is increased accordingly to compensate in advance. The outputs of each channel are proportionally scaled and then superimposed in the DSP using a weighted summation method to obtain the comprehensive control current, which is the final excitation current command. ; The final excitation current command is output as a control signal, and then the power is converted by the power amplifier to generate the corresponding actual excitation current to drive the stator excitation winding to establish the required electromagnetic force in the air gap, which acts on the rotor to achieve stable suspension and vibration suppression.

[0039] The entire algorithm's operation flow is as follows: sensor sampling → signal conditioning → PID main control calculation → LMS notch filter adaptive adjustment → feedforward compensation superposition → excitation current output. This process constitutes a real-time closed-loop control link, enabling the control system to achieve active vibration reduction and adaptive stabilization under strong disturbance conditions.

[0040] Furthermore, the adaptive notch filter can automatically track and lock onto specific frequency vibration components caused by hydraulic pulsations (such as blade frequency, vortex frequency) or electromagnetic imbalances, and generate a control signal with equal amplitude but opposite phase to cancel them out.

[0041] The power amplifier is connected to the control system to convert the control signal into the corresponding excitation current and drive the stator excitation winding to form a dynamic magnetic force, thereby achieving rapid response and adjustment of rotor position and vibration.

[0042] Furthermore, the device also includes a protective bearing, installed on the outside or end of the rotor, made of composite ceramic or polymer wear-resistant material, which has high hardness and good energy absorption performance; such material can absorb about 15% to 25% of the instantaneous energy under radial impact, and can reduce the peak vibration by about 30% to 40% under contact collision conditions, effectively reducing the impact between the rotor and stator and improving the safety and reliability of the control system.

[0043] The device of this invention is used to suppress unit vibration in hydropower units. In the event of device malfunction or power failure, the protective bearing intervenes to bear the rotor load, thereby ensuring the safe operation of the unit.

[0044] In summary, this invention provides an active magnetic levitation bearing vibration damping device for hydroelectric generator units. The device employs an integrated electrical closed-loop and mechanical structure design, achieving tight coupling of sensing, control, drive, and feedback, thus forming a unified dynamic balance control system between the magnetic levitation bearing and the high-speed motor. Through shortening the axis and axially symmetrical arrangement, it effectively reduces inertial deviation and resonance risks, significantly improving the dynamic response and vibration damping performance of the control system.

[0045] Example 2 Based on the same inventive concept, the present invention also provides an active magnetic levitation bearing vibration reduction method for hydroelectric generator units, implemented using the device described in the foregoing embodiments, the method comprising: The radial displacement signal of the rotor is detected in real time by a displacement sensor. The radial displacement signal of the rotor is amplified and filtered by a signal conditioning circuit to obtain a feedback signal that is input to the control system. The control system generates a position offset error based on the difference between the preset displacement command and the feedback signal, and calculates the excitation current command through adaptive PID control, LMS notch filtering and feedforward compensation algorithm. The excitation current command is amplified by the power amplifier and drives the excitation winding of the radial magnetic bearing to form a controllable magnetic force in the air gap, thereby realizing active control of the rotor position and vibration. By using a displacement sensor to detect the radial displacement signal of the rotor in real time and simultaneously using it as feedback input, closed-loop stable regulation of vibration reduction in hydropower units can be achieved.

[0046] Furthermore, the method of detecting the radial displacement signal of the rotor in real time using a displacement sensor, and then amplifying and filtering the radial displacement signal of the rotor through a signal conditioning circuit to obtain a feedback signal input to the control system includes: The radial displacement signal of the rotor detected in real time by the displacement sensor is filtered and amplified to obtain a feedback signal that is input to the control system. The filtering and amplification module includes a low-noise differential amplifier circuit and a filtering stage: An instrumentation amplifier is used to amplify the signal. Noise and interference are removed by using Butterworth low-pass or band-pass filter circuits and DSP internal digital filtering algorithms.

[0047] Furthermore, the method by which the control system generates a position offset error based on the difference between the preset displacement command and the feedback signal, and calculates the excitation current command through adaptive PID control, LMS notch filtering, and feedforward compensation algorithm includes: An adaptive PID algorithm is used as the main control loop, with the rotor radial position offset error as the input, and the PID excitation current is calculated in real time. Based on the stability of PID control, an adaptive notch filter based on LMS algorithm is used to identify and suppress narrowband periodic vibrations caused by hydraulic pulsation, blade frequency and electromagnetic imbalance, and to calculate the excitation compensation current. When the external disturbance signal of turbine operating parameters or flow pulsation is measurable, a feedforward compensation mechanism is introduced to construct a mathematical model of disturbance and displacement response and generate a canceling current that is opposite in phase to the disturbance. The final excitation current command is obtained based on the PID excitation current, excitation compensation current, and cancellation current.

[0048] Furthermore, the adaptive notch filter can automatically track and lock onto specific frequency vibration components caused by hydraulic pulsations or electromagnetic imbalances, and generate a control signal with equal amplitude but opposite phase to cancel them out.

[0049] Furthermore, the method also includes, in the event of an abnormality or power failure in the control system, a protective bearing made of composite ceramic or polymer wear-resistant material is used to bear the rotor load, thereby ensuring the safe operation of the unit.

[0050] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. An active magnetic levitation bearing vibration damping device for hydroelectric generator units, characterized in that, The device includes: a displacement sensor, a control system, a power amplifier, a radial magnetic bearing, an axial magnetic bearing, and a high-speed motor; The displacement sensor is used to detect the radial displacement of the rotor assembly in real time. The control system is used to generate a position offset error based on the difference between a preset displacement command and a feedback signal, and to obtain an excitation current command. The power amplifier is connected to the control system and is used to amplify the excitation current command to drive the excitation winding of the radial magnetic bearing and form a controllable magnetic force in the air gap. The radial magnetic bearing is used to generate radial support force. The stator assembly constitutes the stator part of the radial magnetic bearing. The stator assembly includes an annular stator core with a stacked silicon steel sheet structure and a uniformly distributed excitation winding. The stator core is coaxially sleeved and fixed in the unit frame. A radial working air gap is formed between its inner circular surface and the magnetic sleeve on the rotor assembly. The excitation winding is wound in the pole teeth or slots of the stator core, uniformly distributed along the circumferential direction, and radially facing the rotor magnetic sleeve, so as to form a radial magnetic bearing together with the rotor assembly. The axial magnetic bearing is used to achieve axial positioning and balance; The high-speed motor is used to drive the rotor to rotate.

2. The apparatus according to claim 1, characterized in that, The radial displacement signal of the rotor detected in real time by the displacement sensor is filtered and amplified to obtain a feedback signal that is input to the control system. The filtering and amplification module includes a low-noise differential amplifier circuit and a filtering stage: An instrumentation amplifier is used to amplify the signal. Noise and interference are removed by using Butterworth low-pass or band-pass filter circuits and DSP internal digital filtering algorithms.

3. The apparatus according to claim 1, characterized in that, The control system calculates the excitation current command by integrating adaptive PID control, an adaptive notch filter based on the LMS algorithm, and feedforward compensation control. An adaptive PID algorithm is used as the main control loop, with the rotor radial position offset error as the input, and the PID excitation current is calculated in real time. Based on the stability of PID control, an adaptive notch filter based on LMS algorithm is used to identify and suppress narrowband periodic vibrations caused by hydraulic pulsation, blade frequency and electromagnetic imbalance, and to calculate the excitation compensation current. When the external disturbance signal of turbine operating parameters or flow pulsation is measurable, a feedforward compensation mechanism is introduced to construct a mathematical model of disturbance and displacement response and generate a canceling current that is opposite in phase to the disturbance. The final excitation current command is obtained based on the PID excitation current, excitation compensation current, and cancellation current.

4. The apparatus according to claim 3, characterized in that, Adaptive notch filters can automatically track and lock onto specific frequency vibration components caused by hydraulic pulsations or electromagnetic imbalances, and generate control signals with equal amplitude but opposite phase to cancel them out.

5. The apparatus according to claim 1, characterized in that, The device also includes a protective bearing, installed on the outside or end of the rotor, made of composite ceramic or polymer wear-resistant material; When the control system malfunctions or fails due to power failure, the protective bearings step in to bear the rotor load and ensure the safe operation of the unit.

6. A method for vibration reduction using an active magnetic levitation bearing in hydroelectric generator units, wherein the method is implemented using the device described in any one of claims 1-5, characterized in that, The method includes: The radial displacement signal of the rotor is detected in real time by a displacement sensor. The radial displacement signal of the rotor is amplified and filtered by a signal conditioning circuit to obtain a feedback signal that is input to the control system. The control system generates a position offset error based on the difference between the preset displacement command and the feedback signal, and calculates the excitation current command through adaptive PID control, LMS notch filtering and feedforward compensation algorithm. The excitation current command is amplified by the power amplifier and drives the excitation winding of the radial magnetic bearing to form a controllable magnetic force in the air gap, thereby realizing active control of the rotor position and vibration. The rotor radial displacement signal detected in real time by the displacement sensor is used as feedback input to achieve closed-loop stable regulation of vibration reduction in the hydropower unit.

7. The method according to claim 6, characterized in that, The radial displacement signal of the rotor is detected in real time by a displacement sensor. The radial displacement signal of the rotor is amplified and filtered by a signal conditioning circuit to obtain a feedback signal input to the control system. The radial displacement signal of the rotor detected in real time by the displacement sensor is filtered and amplified to obtain a feedback signal that is input to the control system. The filtering and amplification module includes a low-noise differential amplifier circuit and a filtering stage: An instrumentation amplifier is used to amplify the signal. Noise and interference are removed by using Butterworth low-pass or band-pass filter circuits and DSP internal digital filtering algorithms.

8. The method according to claim 6, characterized in that, The control system generates a position offset error based on the difference between a preset displacement command and a feedback signal. The method for calculating the excitation current command using adaptive PID control, LMS notch filtering, and feedforward compensation algorithms includes: An adaptive PID algorithm is used as the main control loop, with the rotor radial position offset error as the input, and the PID excitation current is calculated in real time. Based on the stability of PID control, an adaptive notch filter based on LMS algorithm is used to identify and suppress narrowband periodic vibrations caused by hydraulic pulsation, blade frequency and electromagnetic imbalance, and to calculate the excitation compensation current. When the external disturbance signal of turbine operating parameters or flow pulsation is measurable, a feedforward compensation mechanism is introduced to construct a mathematical model of disturbance and displacement response and generate a canceling current that is opposite in phase to the disturbance. The final excitation current command is obtained based on the PID excitation current, excitation compensation current, and cancellation current.

9. The method according to claim 8, characterized in that, Adaptive notch filters can automatically track and lock onto specific frequency vibration components caused by hydraulic pulsations or electromagnetic imbalances, and generate control signals with equal amplitude but opposite phase to cancel them out.

10. The method according to claim 6, characterized in that, The method also includes, in the event of an abnormality or power failure in the control system, using a protective bearing made of composite ceramic or polymer wear-resistant material to bear the rotor load and ensure safe operation of the unit.

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