Adaptive magnetic damping mechanism, damping method and application thereof in fan

Abstract

The application discloses a self-adaptive magnetic damping mechanism, a damping method and application of the self-adaptive magnetic damping mechanism and the damping method in a fan, relates to the technical field of fan damping devices, and comprises fixedly arranged magnetic annular grooves, multiple groups of telescopic counterweight strip assemblies integrated in fan blades and a control module, multiple groups of permanent magnets are symmetrically arranged on the two side walls of the magnetic annular grooves, and a gradually enhanced magnetic field is formed along the groove depth direction by reducing the magnet spacing, the telescopic counterweight strip assembly comprises a counterweight strip, end magnets are arranged at the ends of the counterweight strip and the end magnets are arranged to extend into the magnetic annular grooves to generate repulsion, and the control module dynamically adjusts the position of the counterweight strip based on the real-time rotating speed of the fan and a reference mapping relationship between the rotating speed of the fan and a target position of the counterweight strip, so as to adjust the mass distribution and the magnetic support stiffness of the fan blade, and the low-energy-consumption high responsiveness of fan low-speed start-stop and the vibration stability of high-speed operation are realized.

Description

Technical Field

[0001] This invention relates to the field of wind turbine vibration damping devices, and more specifically, to an adaptive magnetic vibration damping mechanism, a vibration damping method, and its application in wind turbine fans. Background Technology

[0002] As widely used power and ventilation equipment, the vibration and noise of fans during operation are key indicators for evaluating performance and quality. Excessive vibration not only generates noise pollution but also accelerates bearing wear, causes structural fatigue, and seriously affects equipment reliability and lifespan. Currently, fan vibration reduction mainly relies on passive technologies, such as adding rubber damping pads to the mounting base or installing damping rings inside the rotor. While these methods are structurally simple, their stiffness and damping parameters are fixed and cannot adapt to the dynamic characteristics of fans that vary over a wide speed range. For example, a high-damping system designed to suppress rapid vibrations may become overdamped at low speeds. This leads to starting difficulties, and conversely, it is impossible to avoid critical speeds at high speeds. Existing active vibration control technologies, such as active magnetic bearings, control the rotor position in real time through electromagnetic force and can avoid critical speeds, but their systems are extremely complex, requiring multi-degree-of-freedom electromagnet arrays, high-precision displacement sensors, high-speed digital controllers, and high-power amplifiers, resulting in high costs, high energy consumption, and reliability challenges, making it difficult to popularize in ordinary wind turbine products. Therefore, existing technologies lack a solution that can adaptively adjust vibration reduction performance according to wind turbine operating conditions while being engineering-feasible in terms of structural complexity, reliability, and cost. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide an adaptive magnetic vibration damping mechanism, method and application. This invention can automatically and continuously adjust the equivalent stiffness and mass distribution of the vibration damping system according to the real-time speed of the fan, thereby achieving optimal vibration suppression under all working conditions such as startup, avoiding critical speeds and high-speed operation, while maintaining a relatively simple system structure, reliable operation and controllable cost.

[0004] To achieve the above objectives, the present invention provides the following technical solution: The present invention provides an adaptive magnetic damping mechanism, which mainly includes: a magnetic annular groove, multiple sets of telescopic counterweights and a control module.

[0005] Furthermore, the magnetic annular groove is fixedly mounted on the stator component of the fan, i.e., the casing or the guide shroud, and is an annular cavity. Its central axis coincides with the fan shaft, and the opening of the groove faces the tip of the fan blade. Multiple sets of permanent magnets are symmetrically arranged on opposite side walls along the width direction inside the magnetic annular groove, and the magnetic polarities of the opposite surfaces of the permanent magnets on opposite side walls are opposite. That is, if the left magnet is on the right side... If the pole is on the right, then the left side of the magnet is on the right. The magnetic field is generated within the magnetic annular groove, and the distance between the permanent magnets on the two side walls gradually decreases along the depth direction of the magnetic annular groove, i.e., from the groove opening to the groove bottom. This results in a monotonically increasing gradient change in the magnetic field strength within the magnetic annular groove from the groove opening to the groove bottom, i.e., the magnetic field is weakest at the groove opening and strongest at the groove bottom, forming a magnetic field distribution that gradually strengthens along the depth direction inside the groove.

[0006] Furthermore, multiple sets of the telescopic counterweight assemblies are integrated inside each fan blade. Each set of telescopic counterweight assemblies includes a counterweight initially located at the blade root and movable radially within the blade, from the blade root to the blade tip; a drive unit for driving the counterweight; and an end magnet located at the end of the counterweight for interacting with the magnetic field inside the magnetic annular groove. The counterweight is made of high-density material to provide greater mass within a limited volume. Each fan blade has a radially extending linear slide rail for radial movement of the counterweight. The counterweight is mounted on the linear slide rail, with one end connected to the drive unit at the blade root and the other end (the end magnet) extending from the blade tip. The end magnet extends into the magnetic annular groove and can move along the depth of the groove. The polarity of the end magnet is configured such that when it extends into the magnetic annular groove... When the magnetic poles on both sides of the magnetic annular groove are the same polarity as the magnetic poles on the corresponding sidewalls of the magnetic annular groove, and the distances from both sides to the corresponding sidewalls of the magnetic annular groove are the same, thus generating radial repulsive forces of opposite direction and equal magnitude on both sides of the end magnet. When the fan blade vibrates and deviates, the magnitude of the radial repulsive force on both sides of the end magnet changes. The changing radial repulsive force generates a force difference opposite to the vibration deviation to counteract the vibration deviation. This force difference further promotes the recovery of the vibration deviation. The drive unit is a miniature linear motor integrated in the root of the fan blade or the hub of the fan blade root, and is electrically connected to the fan shaft through a rotary connector. The drive unit is used to control the position of the counterweight bar moving radially along the fan blade. The drive units in multiple sets of telescopic counterweight bar assemblies adopt synchronous control to ensure that the position of the counterweight bars in each set of telescopic counterweight bar assemblies is consistent, avoiding mass imbalance during the fan blade rotation caused by inconsistent counterweight bar positions. Furthermore, the control module is used to control the drive unit to drive the counterweight bar to move radially within the fan blades based on the real-time speed signal of the fan, and further to cause the end magnet located at the end of the counterweight bar to move along the depth direction inside the magnetic annular groove. The control module includes a main controller, a speed sensor, and a drive circuit. The main controller uses a microprocessor or a digital signal processor. The speed sensor is used to identify the real-time speed of the fan. The drive circuit is used to drive each micro linear motor. The control module and each micro linear motor are electrically connected to the fan shaft through a rotary connector. The main controller also stores a control algorithm for controlling the drive unit, that is, based on the real-time speed, by querying a pre-established reference mapping relationship between the fan speed and the target position of the counterweight bar, instructing each micro linear motor to execute the driving movement of each counterweight bar. That is, the control module is used to execute the following steps: S1. Obtain the real-time fan speed monitored by the speed sensor. ; S2, based on the real-time rotation speed By querying the aforementioned benchmark mapping relationship, the benchmark target position can be obtained. The reference target position This is expressed as the distance the counterweight bar moves radially along the fan blade; S3, Based on the reference target position Control commands are generated and the drive unit is controlled via the drive circuit to drive the counterweight bar according to the reference target position through each micro linear motor. Move.

[0007] Furthermore, in the control module, the reference mapping relationship between the fan speed and the target position of the counterweight is obtained through the following steps: M1. During the wind turbine commissioning phase, the position of the counterweight bar is determined at different locations. At that time, the critical speeds of each order of the wind turbine rotor system ,Location The distance the counterweight bar moves radially along the fan blade is represented by the distance, where, , The maximum limiting distance that the counterweight bar can move radially along the fan blades is represented by the critical speeds for each order. The distance the counterweight moves radially along the fan blade is expressed as... The first time The critical speed, where, The distance the counterweight moves radially along the fan blade is expressed as... Total First critical speed; M2, then, for a given operating speed By defining an optimization problem, namely finding a location This makes the operating speed With all critical speeds Maximizing the minimum relative distance between them, mathematically, is equivalent to solving the objective function. The constraints are ,in, The calculation is the operating speed. With the The relative distance between the first critical speeds It is the absolute difference, representing how much the two differ. Divide the absolute difference by... This is for normalization, because the critical speed values ​​for different orders can vary greatly. After normalization, a percentage is obtained to represent the operating speed. The relative degree of deviation from this critical speed. This is represented by the position of a fixed counterweight bar. Calculate the operating speed The relative distances to all critical speeds that need to be considered are then taken, and the minimum of these is taken. This minimum value represents the position of the current counterweight bar. Below, current operating speed The greatest risk of resonance faced by the bottom is ultimately through The function is located at all possible positions of the counterweight. The search is performed within the specified range, i.e., within the constraints. The search will proceed to find a specific error. Value, so that according to The calculated minimum relative distance reaches its maximum, thus achieving the optimal operating speed. With each critical speed The optimal reference position is determined by maximizing the minimum relative distance between the two positions, thus forming the reference mapping relationship. By solving this problem for a given series of discrete operating speeds, a curve describing the relationship between the operating speed and the optimal reference position can be obtained, i.e. , This is expressed as the relationship between the operating speed and the optimal reference position. When the operating speed is 0, the counterweight is initially located at the blade root, meaning the blade's center of gravity is biased towards the blade root to provide a smaller moment of inertia. Simultaneously, the end magnet extends shallowly into the magnetic annular groove, resulting in lower additional energy consumption from the magnetic field, thus improving the fan's start-up response speed and reducing its start-up energy consumption. As the operating speed gradually increases, the optimal reference position changes. The counterweight moves and extends according to the optimal reference position as the operating speed increases, shifting the fan blade's center of gravity towards the blade tip to provide a larger moment of inertia and causing the end magnet to extend deeper into the magnetic annular groove to obtain greater magnetic support stiffness. The greater moment of inertia and greater magnetic support stiffness improve the fan blade vibration stability as the operating speed increases. However, due to the existence of a critical speed, the reference mapping relationship is non-linear. For example, when the operating speed increases to near a certain critical speed... The counterweight bar can be driven to retract quickly instead of extending further to actively avoid the critical speed, thereby achieving a smooth crossing of the critical speed.

[0008] In another aspect, the present invention provides an adaptive magnetic damping method, applied to the adaptive magnetic damping mechanism described above, specifically including the following steps: The fan speed signal is acquired in real time; the target position of the counterweight bar is calculated based on the acquired fan speed signal and the preset reference mapping relationship; the control drive unit adjusts the counterweight bar to the target position, and at the same time, the end magnet of the end of the counterweight bar moves along the depth direction in the magnetic annular groove.

[0009] The present invention also includes a fan that includes the adaptive magnetic damping mechanism described above.

[0010] Beneficial Effects: In summary, this invention provides an adaptive magnetic vibration damping mechanism, method, and application. The beneficial effects of this invention lie in achieving an adaptive optimal vibration damping and suppression solution for the entire operating condition of the fan through the coordinated telescopic counterweight assembly and the gradient magnetic field distribution of the magnetic annular groove. The adaptive magnetic vibration damping mechanism of this invention can dynamically adjust the mass distribution and magnetic support stiffness of the fan blade structure according to the real-time rotational speed. It not only perfectly balances the low energy consumption and high responsiveness of low-speed start-stop with the vibration stability of high-speed operation, overcoming the inherent limitations of fixed parameters in traditional passive vibration damping devices, but also actively regulates the critical speed of the fan blade rotor to safely and smoothly pass through the resonance zone. At the same time, this invention, through the telescopic counterweight, can further optimize the position of the counterweight to minimize the moment of inertia while ensuring the vibration damping effect, achieving a balance between vibration control and operating energy efficiency, and achieving the effects of reducing operating noise, reducing transmitted vibration, and reducing additional energy consumption.

[0011] Other features and advantages of the present invention will be set forth in the following description. Attached Figure Description

[0012] To more clearly illustrate the embodiments of the present invention, the accompanying drawings used in the embodiments will be 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.

[0013] Figure 1 This is a partial structural diagram of an adaptive magnetic damping mechanism according to an embodiment of the present invention. Figure 1 ; Figure 2 This is a partial structural diagram of an adaptive magnetic damping mechanism according to an embodiment of the present invention. Figure 2 In the diagram, A is the magnetic annular groove; B is the counterweight bar; C is the end magnet; and D is the permanent magnet. Detailed Implementation

[0014] The present invention will be described below with reference to specific embodiments. It should be noted that the embodiments described below are examples of the present invention and are only used to illustrate the present invention, and are not intended to limit the present invention. Other combinations and various modifications within the scope of the present invention can be made without departing from the spirit or scope of the present invention.

[0015] Figure 1 This is a partial structural schematic diagram of an adaptive magnetic damping mechanism according to an embodiment of the present invention, as shown below. Figure 1 As shown, this embodiment provides an adaptive magnetic damping mechanism, which includes a magnetic annular groove A, multiple sets of telescopic counterweights, and a control module. Specifically, the magnetic annular groove A is fixedly installed on the stator component of the fan, i.e., the casing or the flow guide. Figure 1 As shown, the magnetic annular groove A is an annular groove whose central axis coincides with the fan shaft. The groove opening faces the tip of the fan blade, and the groove interior contains a magnetic field that gradually increases in depth. Multiple sets of telescopic counterweight assemblies are integrated inside each fan blade. Each telescopic counterweight assembly includes a counterweight B initially located at the root of the fan blade and capable of moving radially within the blade, a drive unit (not shown in the figure) for moving the counterweight B, and an end magnet C located at the end of the counterweight B for interacting with the magnetic field inside the magnetic annular groove A. Figure 1 As shown, the end magnet C extends from the tip of the fan blade and into the groove of the magnetic annular groove A, and can move along the depth direction inside the groove. The control module is used to control the drive unit to drive the counterweight bar B to move radially inside the fan blade according to the real-time speed signal of the fan, and further cause the end magnet C located at the end of the counterweight bar B to move along the depth direction inside the groove of the magnetic annular groove A.

[0016] Figure 2 This is a partial structural schematic diagram of an adaptive magnetic damping mechanism according to an embodiment of the present invention, as shown below. Figure 2 As shown, multiple sets of permanent magnets D are symmetrically arranged on opposite side walls along the width direction inside the magnetic annular groove A. The magnetic poles of the permanent magnets D on opposite side walls have opposite polarities, and the spacing between the permanent magnets D on opposite side walls gradually decreases along the depth direction of the magnetic annular groove. The polarity of the end magnet C is configured such that when it extends into the magnetic annular groove A, the magnetic poles on both sides have the same polarity as the corresponding side wall of the magnetic annular groove A, and the distances from both sides of it to the corresponding side wall of the magnetic annular groove are the same. The control module includes a main controller, a speed sensor, and a drive circuit. The main controller stores the reference mapping relationship between the fan speed and the target position of the counterweight bar B and is used to execute the following steps: S1, acquire the real-time fan speed monitored by the speed sensor. S2, based on real-time rotational speed Query the baseline mapping relationship to obtain the baseline target location. Baseline target position S3 represents the distance that counterweight B moves radially along the fan blade; based on the reference target position. The system generates control commands and drives the drive unit via the drive circuit to move the counterweight bar B according to the reference target position. Move; The reference mapping relationship between the fan speed and the target position of counterweight B is obtained through the following steps: M1, obtaining the counterweight B at different positions. At that time, the critical speeds of each order of the wind turbine rotor system ,Location This represents the distance that counterweight B moves radially along the fan blade, where... , The critical speeds for each order represent the maximum limiting distance that counterweight B can move radially along the fan blade. The distance that counterweight B moves radially along the fan blade is expressed as... The first time The critical speed, where, This is expressed as the distance that counterweight B moves radially along the fan blade. Total First critical speed; M2, for a given operating speed Solve the objective function This results in the operating speed. With each critical speed The optimal reference position is found by maximizing the minimum relative distance between them, thus forming a reference mapping relationship.

[0017] This embodiment also provides an adaptive magnetic vibration damping method, applied to the adaptive magnetic vibration damping mechanism described above, specifically including the following steps: acquiring the fan speed signal in real time; calculating the target position of the counterweight B based on the acquired fan speed signal and a preset reference mapping relationship; controlling the drive unit to adjust the counterweight B to the target position, while the end magnet C at the end of the counterweight B moves along the depth direction in the magnetic annular groove A.

[0018] This embodiment also provides a fan that includes the adaptive magnetic damping mechanism described above.

[0019] For example, in a specific application scenario of an axial cooling fan for a high-density server, an adaptive magnetic damping mechanism is included, wherein the adaptive magnetic damping mechanism includes: a magnetic annular groove: the annular groove is made of engineering plastic, and multiple rows of neodymium iron boron permanent magnets are embedded in the opposite side walls of the groove along the depth direction, and the center distance between the opposite magnets in the opposite side walls gradually decreases from the groove opening to the groove bottom, so as to form a magnetic field that gradually strengthens along the depth direction in the groove. Telescopic counterweight assembly: The fan blades are made of reinforced engineering plastic, and a radial linear slide rail with a rectangular cross section is formed inside each fan blade by molding. The counterweight is made of tungsten copper alloy, and a neodymium iron boron magnetic strip is bonded to the end of the counterweight as an end magnet. The drive unit is a micro linear motor, which is integrated into the hub at the root of the fan blade. It is installed on the fan shaft and electrically connected by a rotary connector. At the same time, the drive end of the micro linear motor is connected to the counterweight. Control module: Also integrated in the hub of the fan blade root, the main controller uses a microprocessor, the speed signal is obtained from the fan motor driver, and the reference mapping relationship between the fan speed and the target position of the counterweight is pre-stored in the main controller as a control algorithm; Working process: The server is powered on, the fan starts, and the speed increases from 0. The counterweight is initially located at the root of the fan blade. The fan blade has a small initial moment of inertia, and the start-up is rapid. The speed gradually increases, and the optimal reference position of the counterweight changes according to the reference mapping relationship. The control module drives the counterweight to move and extend according to the optimal reference position as the working speed increases by controlling the micro linear motor. This shifts the center of gravity of the fan blade towards the tip of the fan blade to provide a greater moment of inertia and allows the end magnet to extend deeper into the magnetic annular groove to obtain greater magnetic support stiffness. The greater moment of inertia and greater magnetic support stiffness improve the vibration stability of the fan blade when the working speed increases.

[0020] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. An adaptive magnetic damping mechanism, characterized in that, include: A magnetic annular groove is fixedly installed on the stator component of the fan. The magnetic annular groove is an annular groove whose central axis coincides with the fan shaft. The opening of the groove faces the tip of the fan blade, and the groove contains a magnetic field that gradually increases in depth. Multiple sets of telescopic counterweight assemblies are integrated inside each fan blade. Each set of telescopic counterweight assembly includes a counterweight initially located at the root of the fan blade and movable radially within the fan blade, a drive unit for driving the counterweight, and an end magnet located at the end of the counterweight for interacting with the magnetic field inside the magnetic annular groove. The end magnet extends from the tip of the fan blade and into the groove of the magnetic annular groove, and can move along the depth direction inside the groove. A control module controls the drive unit to drive the counterweight to move radially within the fan blade based on the real-time speed signal of the fan, and further causes the end magnet located at the end of the counterweight to move along the depth direction inside the magnetic annular groove.

2. The adaptive magnetic damping mechanism according to claim 1, characterized in that, Multiple sets of permanent magnets are symmetrically arranged in the two opposite side walls along the width direction inside the magnetic annular groove. The magnetic poles of the permanent magnets in the opposite side walls are opposite, and the spacing between the permanent magnets in the opposite side walls gradually decreases along the depth direction of the magnetic annular groove.

3. The adaptive magnetic damping mechanism according to claim 1, characterized in that, The polarity of the end magnet is configured such that when it extends into the magnetic annular groove, the magnetic poles on both sides have the same polarity as the magnetic poles of the corresponding sidewalls of the magnetic annular groove, and the distances on both sides from the corresponding sidewalls of the magnetic annular groove are the same.

4. The adaptive magnetic damping mechanism according to claim 1, characterized in that, The control module includes a main controller, a speed sensor, and a drive circuit. The main controller stores a reference mapping relationship between the fan speed and the target position of the counterweight bar, and is used to execute the following steps: S1, acquire the real-time fan speed monitored by the speed sensor. ; S2, based on the real-time rotation speed By querying the aforementioned benchmark mapping relationship, the benchmark target position can be obtained. The reference target position S3, based on the reference target position, represents the distance the counterweight bar moves radially along the fan blade. The system generates control commands and controls the drive unit via the drive circuit to drive the counterweight bar according to the reference target position. Move.

5. The adaptive magnetic damping mechanism according to claim 4, characterized in that, The baseline mapping relationship between the fan speed and the target position of the counterweight is obtained through the following steps: M1, obtaining the counterweight at different positions. At that time, the critical speeds of each order of the wind turbine rotor system ,Location The distance the counterweight bar moves radially along the fan blade is represented by the distance, where, , The maximum limiting distance that the counterweight bar can move radially along the fan blades is represented by the critical speeds for each order. The distance the counterweight moves radially along the fan blade is expressed as... The first time The critical speed, where, The distance the counterweight moves radially along the fan blade is expressed as... Total First critical speed; M2, for a given operating speed Solve the objective function This results in the operating speed. With each critical speed The optimal reference position is determined by maximizing the minimum relative distance between them, thereby forming the reference mapping relationship.

6. An adaptive magnetic damping method, applied to the adaptive magnetic damping mechanism according to any one of claims 1-5, characterized in that, Specifically, the following steps are included: The fan speed signal is acquired in real time; the target position of the counterweight bar is calculated based on the acquired fan speed signal and the preset reference mapping relationship; the control drive unit adjusts the counterweight bar to the target position, and at the same time, the end magnet of the end of the counterweight bar moves along the depth direction in the magnetic annular groove.

7. A fan, characterized in that, The adaptive magnetic damping mechanism includes any one of claims 1-5.

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