CN113124053B - Synchronous damping method and device - Google Patents
Synchronous damping method and device Download PDFInfo
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C32/00—Bearings not otherwise provided for
- F16C32/04—Bearings not otherwise provided for using magnetic or electric supporting means
- F16C32/0406—Magnetic bearings
- F16C32/044—Active magnetic bearings
- F16C32/0444—Details of devices to control the actuation of the electromagnets
- F16C32/0446—Determination of the actual position of the moving member, e.g. details of sensors
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C32/00—Bearings not otherwise provided for
- F16C32/04—Bearings not otherwise provided for using magnetic or electric supporting means
- F16C32/0406—Magnetic bearings
- F16C32/044—Active magnetic bearings
- F16C32/0444—Details of devices to control the actuation of the electromagnets
- F16C32/0451—Details of controllers, i.e. the units determining the power to be supplied, e.g. comparing elements, feedback arrangements with P.I.D. control
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- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C32/00—Bearings not otherwise provided for
- F16C32/04—Bearings not otherwise provided for using magnetic or electric supporting means
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- F16C32/0474—Active magnetic bearings for rotary movement
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- F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16F15/00—Suppression of vibrations in systems; Means or arrangements for avoiding or reducing out-of-balance forces, e.g. due to motion
- F16F15/002—Suppression of vibrations in systems; Means or arrangements for avoiding or reducing out-of-balance forces, e.g. due to motion characterised by the control method or circuitry
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- F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16F15/00—Suppression of vibrations in systems; Means or arrangements for avoiding or reducing out-of-balance forces, e.g. due to motion
- F16F15/02—Suppression of vibrations of non-rotating, e.g. reciprocating systems; Suppression of vibrations of rotating systems by use of members not moving with the rotating systems
- F16F15/03—Suppression of vibrations of non-rotating, e.g. reciprocating systems; Suppression of vibrations of rotating systems by use of members not moving with the rotating systems using magnetic or electromagnetic means
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- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C2300/00—Application independent of particular apparatuses
- F16C2300/20—Application independent of particular apparatuses related to type of movement
- F16C2300/22—High-speed rotation
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Abstract
The invention discloses a synchronous damping method and a device, wherein the method comprises the following steps: detecting a rotor real-time displacement signal and a phase discrimination signal; carrying out self-adaptive filtering on the real-time displacement signal by using the phase discrimination signal so as to extract the same-frequency vibration component of the rotor from the real-time displacement signal; amplifying and vector converting the same-frequency vibration components to output a synchronous damping signal opposite to the direction of the vortex speed of the rotor, and generating a synchronous damping force according to the synchronous damping signal to suppress the critical vibration of the rotor through the synchronous damping force. According to the method, synchronous damping current is used to replace the same-frequency output current of an asynchronous controller, so that negative effects caused by overhigh gain of a traditional supercritical controller are avoided, electromagnetic damping force aiming at critical whirling of a rotor is generated more efficiently, and the utilization efficiency of electromagnetic force is improved.
Description
Technical Field
The invention relates to the technical field of magnetic bearing rotor control, in particular to a synchronous damping method and a synchronous damping device.
Background
Modern rotary machines are developing to higher rotating speed, higher machine efficiency and higher precision, and the high-speed operation of a rotor often needs to exceed the flexible critical rotating speed, so that the flexible critical vibration problem has to be faced. The key to the stable operation of the rotor in a higher rotating speed range is to inhibit the critical vibration.
The rotor inevitably has unbalanced mass due to the influence of factors such as uneven materials, machining errors and the like. When the rotor runs, the unbalanced mass generates unbalanced force, the unbalanced force is synchronous with the rotating speed of the rotor, and the magnitude of the unbalanced force is in direct proportion to the square of the rotating speed. The residual unbalance of the high-speed rotor has a significant influence on the system vibration level and reliability. As the most main rotor excitation source, the unbalanced force is near the critical rotating speed, and the excitation effect on the rotor vibration is particularly outstanding.
The inhibition of the unbalanced critical vibration has two main ways, namely, the precise dynamic balance of the rotor is carried out, the residual unbalance of the rotor is reduced, and the exciting force is reduced from the source; and secondly, damping is provided through the supporting part, the vibration energy of the rotor is effectively attenuated, and the harmonic response peak value of the rotor is reduced.
From a balance cost perspective, precision dynamic balance is limited at the level of engineering achievable, which is reflected in relevant industry standards. In addition, in the process of high-speed rotor operation, due to the fact that stress of rotor materials is released, the temperature distribution of the rotor is unbalanced, local materials generate plastic deformation and the like, and the amount of unbalance can be changed. Thus, vibration damping will depend on the damping provided by the support member after the dynamic balance reaches a certain balance level.
The electromagnetic bearing supports the ferromagnetic rotor through controlled electromagnetic force, and non-contact suspension of the rotor is realized. When the electromagnetic bearing is applied to a supercritical rotor or used as a damper to work, the characteristic that the supporting characteristic of the electromagnetic bearing can be adjusted along with the frequency is utilized, and the critical damping can be provided for the rotor by adjusting the parameters of a controller near the critical frequency. However, when the critical frequency is relatively high, it is limited by factors such as the bandwidth of the system, and it is very challenging for the electromagnetic bearing to provide an effective electromagnetic damping force for the critical vibration. The electromagnetic force output by the electromagnet has the advance characteristic relative to the rotor displacement so as to effectively damp the vibration. In order to obtain the phase advance of the electromagnetic force, the controller parameters need to be finely adjusted, and the adjustment of the controller parameters is limited by various factors such as other vibration modes, system noise level and the like, so that it is very difficult to obtain sufficient electromagnetic damping force in an actual system.
In the high-speed supercritical state of the rotor, the phase advance characteristic in a local frequency range can be improved by means of parameter adjustment of a magnetic bearing controller, but the improvement is limited by various factors, electromagnetic force provides damping, a large specific gravity force can be used as elastic feedback force, and the utilization rate of bearing capacity is limited because the elastic feedback force cannot be used for attenuating vibration energy of the rotor. Moreover, this approach often excites the system high-frequency mode vibration while improving critical damping at the cost of greatly increasing the controller high-frequency gain.
Disclosure of Invention
The present invention is directed to solving, at least to some extent, one of the technical problems in the related art.
Therefore, an object of the present invention is to provide a synchronous damping method, in which synchronous damping current is used to replace the same-frequency output current of an asynchronous controller, so as to avoid the negative effect caused by too high gain of the conventional supercritical controller, generate an electromagnetic damping force for the critical whirling of a rotor more efficiently, and improve the utilization efficiency of the electromagnetic force.
Another object of the present invention is to provide a synchronous damping device.
In order to achieve the above object, an embodiment of an aspect of the present invention provides a synchronous damping method, including the following steps: detecting a rotor real-time displacement signal and a phase discrimination signal; carrying out self-adaptive filtering on the real-time displacement signal by using the phase discrimination signal so as to extract a same-frequency vibration component of the rotor from the real-time displacement signal; amplifying and vector-converting the same-frequency vibration components to output a synchronous damping signal opposite to the direction of the vortex speed of the rotor, and generating a synchronous damping force according to the synchronous damping signal to suppress the critical vibration of the rotor through the synchronous damping force.
According to the synchronous damping method, synchronous damping current is used for replacing the same-frequency output current of the controller, so that negative effects caused by overhigh gain of the traditional supercritical controller can be effectively avoided, electromagnetic damping force aiming at the critical vortex motion of the rotor is generated more efficiently, and the electromagnetic force utilization efficiency is effectively improved; in addition, the critical vortex motion damping is provided by the control force generated by the original magnetic bearing controller (asynchronous), and is provided by the synchronous damping force instead, so that the design difficulty of the magnetic bearing supercritical controller is effectively reduced.
In addition, the synchronous damping method according to the above embodiment of the present invention may further have the following additional technical features:
further, in an embodiment of the present invention, the method further includes: and superposing the synchronous reverse phase shift signal output by the self-adaptive filtering with the real-time displacement signal to filter out synchronous displacement.
Further, in one embodiment of the present invention, the outputting a synchronous damping signal in a direction opposite to a whirling speed of the rotor includes: rotating the amplified same-frequency vibration component subjected to vector transformation by a first preset angle; and obtaining the synchronous damping signal according to the product of the rotated vector same-frequency vibration component and a preset coefficient.
Further, in an embodiment of the present invention, before amplifying and vector-transforming the same-frequency vibration components, the method further includes: and acquiring a mass eccentricity vector and a displacement eccentricity vector, and calculating an angle of the mass eccentricity vector leading the displacement eccentricity vector. Estimating an advance angle according to a modal circle method in rotor dynamics, or estimating the advance angle according to a difference value between the current rotating speed and a critical rotating speed; and judging whether the advance angle is larger than a critical angle or not, and if so, determining that the rotating speed of the rotor is at the critical rotating speed.
Further, in an embodiment of the present invention, when the rotation speed of the rotor is at a critical rotation speed, the first preset angle may be 90 degrees.
In order to achieve the above object, another embodiment of the present invention provides a synchronous damping device, including: the detection module is used for detecting a rotor real-time displacement signal and a phase discrimination signal; the filtering module is used for carrying out self-adaptive filtering on the real-time displacement signal by utilizing the phase discrimination signal so as to extract a same-frequency vibration component of the rotor from the real-time displacement signal; and the control module is used for amplifying and vector-converting the same-frequency vibration components to output a synchronous damping signal opposite to the direction of the vortex speed of the rotor, and generating a synchronous damping force according to the synchronous damping signal to inhibit the critical vibration of the rotor through the synchronous damping force.
According to the synchronous damping device provided by the embodiment of the invention, the synchronous damping current is used for replacing the same-frequency output current of the controller, so that the negative effect caused by overhigh gain of the traditional supercritical controller can be effectively avoided, and the electromagnetic damping force aiming at the critical whirling of the rotor can be generated more efficiently, thereby effectively improving the utilization efficiency of the electromagnetic force; in addition, the critical vortex motion damping is provided by the control force generated by the original magnetic bearing controller (asynchronous), and is provided by the synchronous damping force instead, so that the design difficulty of the magnetic bearing supercritical controller is effectively reduced.
In addition, the synchronous damping device according to the above embodiment of the present invention may further have the following additional technical features:
further, in an embodiment of the present invention, the method further includes: and the superposition module is used for superposing the synchronous anti-phase shift signal output by the self-adaptive filtering and the real-time shift signal so as to filter out synchronous shift.
Further, in an embodiment of the present invention, the control module is further configured to rotate the amplified and vector-transformed common-frequency vibration component by a first preset angle, and obtain the synchronous damping signal according to a product of the rotated vector common-frequency vibration component and a preset coefficient.
Further, in an embodiment of the present invention, the control module is further configured to, before amplifying and vector-transforming the same-frequency vibration components, obtain a mass eccentricity vector and a displacement eccentricity vector, and calculate an angle at which the mass eccentricity vector leads the displacement eccentricity vector, wherein the lead angle is estimated according to a modal circle method in rotor dynamics, or the lead angle is estimated according to a difference between a current rotational speed and a critical rotational speed; and judging whether the advance angle is larger than a critical angle or not, and if so, determining that the rotating speed of the rotor is at the critical rotating speed.
Further, in an embodiment of the present invention, when the rotation speed of the rotor is at a critical rotation speed, the first preset angle may be 90 degrees.
Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Drawings
The foregoing and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
FIG. 1 is a schematic view of a single-disk rotor model provided in accordance with an embodiment of the present invention;
FIG. 2 is a rotor whirl curve provided in accordance with an embodiment of the present invention;
FIG. 3 is a graph of a disk center spiral decay trace provided in accordance with an embodiment of the present invention;
FIG. 4 is a schematic diagram of a disc motion in the presence of mass eccentricity provided in accordance with an embodiment of the present invention;
FIG. 5 is a schematic diagram illustrating the relationship between O, O' and point C at different rotational speeds according to an embodiment of the present invention;
FIG. 6 is a diagram of an ideal differentiator and an actual differentiator Bode provided according to an embodiment of the present invention;
FIG. 7 is a flow chart of a synchronous damping method provided in accordance with an embodiment of the present invention;
FIG. 8 is a schematic diagram of a synchronous damping implementation mechanism provided in accordance with an embodiment of the present invention;
FIG. 9 is a schematic diagram of the principle of synchronous damping provided according to an embodiment of the present invention;
fig. 10 is a block diagram of GNF synchronous damping provided in accordance with an embodiment of the present invention;
FIG. 11 shows a schematic diagram of a method for generating a signal according to an embodiment of the present inventionfA structure diagram;
FIG. 12 is a schematic diagram of a method for providing N according to an embodiment of the present inventionsA structure diagram;
FIG. 13 is a diagram illustrating the relationship between synchronous damping current and vibration displacement according to an embodiment of the present invention;
fig. 14 is a block diagram of a synchronous damping device according to an embodiment of the present invention.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.
In order to improve the effective utilization rate of the electromagnetic force, a method for more efficiently generating damping force needs to be researched, and therefore, the embodiment of the invention provides a method for improving critical damping through synchronous control, namely a magnetic bearing synchronous damping method. The basic idea of synchronous control is to obtain gain phase information of the rotor by detecting the synchronous displacement vibration of the rotor on line, and based on the information, superimpose a sinusoidal signal with specific gain and phase in a control loop, thereby effectively changing the synchronous motion state of the rotor. The working principle of the synchronous damping method of the magnetic bearing is as follows: the synchronous control principle is adopted to eliminate the same-frequency control current of an output channel of the asynchronous controller, and the same-frequency control current is replaced by an electromagnetic force which is directly generated by a synchronous damping channel and leads the rotor to carry out 90-degree vortex motion, acts on the rotor and inhibits the critical vibration of the rotor; the electromagnetic force is advanced by 90 degrees in advance of the rotor whirl, which is essentially equivalent to obtaining pure damping force for the rotor whirl, so that high electromagnetic force utilization efficiency can be obtained.
To explain the specific mechanism of the magnetic bearing synchronous damping method, the embodiment of the invention firstly introduces a simple single-disk rotor model and analyzes the critical vibration of the model, and the critical vibration characteristics of the model and the supercritical rotor of the magnetic bearing have common parts, specifically as follows:
the single-disc rotor model is shown in figure 1, and the rotor consists of a disc and a non-mass elastic rotating shaft, wherein the disc is arranged in the center of the shaft, and two ends of the rotating shaft are rigidly hinged. When the rotating shaft is not deformed, the disc middle point O' is coincided with the rotating shaft middle point O. The autorotation speed of the rotor is omega, and the distance between O' and O is r when the rotating shaft deforms.
Under the undamped condition, the differential equation of the motion of the center of the disc is as follows:
wherein: m is the disc mass and k is the spindle stiffness. The resonant frequency of the disc supported by the shaft is
Comprises the following steps:
the solution to equation 2 is:
as can be seen from equation 3, the motions of the rotor in the x and y directions are both simple harmonic vibrations with the same frequency. The ratio of X, Y,
the specific value is determined by the initial condition, and the track of O' is generally an ellipse, which is called asWhirling of the rotor. Defining the complex variable z ═ x + jy, which can be derived from equation 2:
the solution is:
the rotor whirl characterized by equation 5 can occur as follows:
1.B1≠0，B 20 positive whirl, with radius | B1A circle of |.
2.B1＝0，B2Not equal to 0 reverse whirl, track is radius | B2A circle of |.
3.B1＝B2，B1、B2The track not equal to 0 is a straight line.
4.B1≠B2，B1、B2Track not equal to 0 is ellipse (| B)1|>|B2L positive whirl; i B1|<|B2Reverse whirl).
The corresponding motion trajectory plane curve is shown in fig. 2. When the rotor is accelerated under unbalanced excitation, the direction of the vortex is the same as the direction of rotation of the rotor.
When there is damping of the rotor motion, equation 4 becomes:
the solution of equation 6 is:
at this time, the movement locus of the center of the disc is a spiral attenuation curve shown in fig. 3.
Consider a disc with mass eccentricity as shown in figure 4. At this time, the elastic restoring force borne by the disc is F, the damping force is R, the center of mass C of the disc and the centroid O' have a deviation e, and the motion equation is formula 8:
the special solution is as follows:
z＝rej(Ωt-θ) (9)
in equation 9, θ is an angle between CO 'representing the mass eccentricity direction and OO' representing the displacement eccentricity direction, and equation 9 is substituted into equation 8 to obtain:
in equation 10, let the real and imaginary parts on both sides of the equation be equal to obtain:
2σΩr＝eΩ2sinθ (12)
defining the frequency ratio lambda as omega/omeganDamping ratio ζ ═ σ/ωnFrom the equations 11 and 12, the relationship between the amplitude ratio of the rotor displacement eccentricity and the mass eccentricity as the rotation speed changes (i.e. the amplitude-frequency characteristic) is:
the relationship between θ and ζ and λ (i.e. the phase-frequency characteristics thereof) is:
the relationship between O, O' and point C at different speeds is shown in FIG. 5.
As can be seen from fig. 5, when the rotation speed is far from the critical rotation speed, the amplitude of the axis is small, and the vibration displacement phase is slightly behind the eccentric excitation; when the rotating speed is equal to the critical rotating speed, the amplitude is large, the specific magnitude depends on vibration damping, and the vibration displacement phase lags behind the eccentric excitation by about 90 degrees at the moment; when the rotating speed is far higher than the critical rotating speed, the amplitude of the rotor is equal to the eccentricity, and the vibration and the eccentric excitation phase are opposite. The eccentricity approaches to the rotating shaft, and then self-centering occurs.
From the above analysis, it is difficult to effectively suppress critical vibration by adjusting the support rigidity alone when the rotor is to perform supercritical operation. In the absence of damping, at the critical speed, the unbalanced driving force component orthogonal to the vibration displacement will continue to provide energy for the rotor revolution, causing it to accelerate continuously. Under the condition of unchanged supporting rigidity, the revolution radius is continuously increased, and the track of the axial center of the rotor is spirally diverged, so that destructive results are caused. This conclusion holds not only for this single-disk rotor model, but also for a magnetically supported supercritical rotor.
To counter the unbalanced excitation force, a damping force orthogonal to the direction of vibration displacement and opposite to the direction of the unbalanced force needs to be applied to the disk. The vibration suppression force is usually obtained by means of speed feedback, namely, the system applies damping force which is in direct proportion to the movement speed to the rotor in a closed-loop feedback mode to realize the attenuation of vibration energy. This is essentially the operating principle of the damper, providing damping of the whirling motion by force feedback to the speed of the whirling motion of the rotor. However, it is difficult to directly measure the moving speed of the rotor, and a speed signal is usually obtained by a speed observer based on the obtained displacement measurement signal.
The gain of an ideal speed observer, namely a differential unit, tends to be infinite along with the continuous increase of the frequency of an input signal, and a noise signal with small amplitude in a high frequency band can generate large influence on the response of a system and even destroy the stability of a closed-loop system under the action of a differentiator. Thus, the differentiating unit often has to be used with a low pass filter to control its high frequency gain. One important consequence of this is that the phase advance characteristic is degraded, which corresponds to a significant portion of the differential gain being proportional, without damping. A Bode plot of an ideal differentiator (solid line) versus an actual differentiator (broken line) with a break-over frequency (1000Hz) as shown in fig. 6, the actual differentiator gain is limited from the break-over frequency at the expense of a phase lead already significantly behind 90 degrees near the break-over frequency and close to 0 as the frequency is higher and away from the break-over frequency.
Since noise signals are unavoidable and high frequency gains excite high frequency modes of the system, introducing potential dynamic instability, it is difficult to suppress critical vibrations of the rotor simply by applying differential damping. In order to more effectively suppress critical vibration, the embodiment of the application provides a synchronous damping method and device for a magnetic bearing.
The synchronous damping method and apparatus proposed according to the embodiments of the present invention will be described below with reference to the accompanying drawings, and first, the synchronous damping method proposed according to the embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 7 is a flow chart of a synchronous damping method of one embodiment of the present invention.
Specifically, as shown in fig. 7, the synchronous damping method includes the steps of:
in step S101, a rotor real-time displacement signal and a phase detection signal are detected.
It can be understood that in the embodiment of the present invention, the real-time displacement signal of the rotor can be obtained by the displacement sensor, and the phase-detected signal can be detected by the phase detector.
In step S102, the real-time displacement signal is adaptively filtered by using the phase-discriminated signal, so as to extract the same-frequency vibration component of the rotor from the real-time displacement signal.
In one embodiment of the invention, the synchronous anti-phase shift signal output by the adaptive filtering is superposed with the real-time displacement signal to filter out the synchronous displacement.
Specifically, as shown in fig. 8, the adaptive filtering unit extracts the same-frequency component in the displacement signal by using the phase-discriminated signal, outputs the synchronous reverse phase-shifted signal to be superimposed with the original displacement signal, filters out the synchronous displacement, and avoids the controller (i.e., the asynchronous controller) in fig. 8 from outputting the same-frequency electromagnetic control force with lower efficiency. There are various implementations of adaptive filtering, for example, a classical approach is a General Notch Filter (GNF), and the GNF method may be used for adaptive filtering in the embodiments of the present invention.
In step S103, the same-frequency vibration components are amplified and vector-converted to output a synchronous damping signal in a direction opposite to the swirling speed of the rotor, and a synchronous damping force is generated according to the synchronous damping signal to suppress critical vibration of the rotor by the synchronous damping force.
It can be understood that, as shown in fig. 8, in the embodiment of the present invention, the displacement same-frequency component may be amplified and vector-converted, and then a synchronous component opposite to the direction of the rotor whirl speed, that is, a synchronous damping signal, is output and superimposed to the controller output to generate a synchronous damping force for damping the rotor whirl.
In one embodiment of the present invention, outputting a synchronous damping signal in a direction opposite to a whirling speed of a rotor includes: rotating the amplified same-frequency vibration component subjected to vector transformation by a first preset angle; and obtaining a synchronous damping signal according to the product of the rotated vector same-frequency vibration component and a preset coefficient. When the rotation speed of the rotor is at the critical rotation speed, the first preset angle may be 90 degrees.
Further, in an embodiment of the present invention, before amplifying and vector-transforming the same-frequency vibration components, the method further includes: acquiring a mass eccentricity vector and a displacement eccentricity vector, and calculating the angle of the mass eccentricity vector in advance of the displacement eccentricity vector, wherein the advance angle is estimated according to a modal circle method in rotor dynamics, or the advance angle is estimated according to the difference value of the current rotating speed and the critical rotating speed; and judging whether the advance angle is larger than a critical angle or not, and if so, determining that the rotating speed of the rotor is at the critical rotating speed.
The critical angle may be regarded as the angle at which the mass eccentricity vector leads the displacement eccentricity vector by about 90 degrees, but may be set to a range, for example, within 45 degrees from 90 degrees. The advance angle can be estimated by reference to a modal circle method in rotor dynamics, or simply by the size of the interval between the current rotational speed and the critical rotational speed.
Specifically, as shown in fig. 9, the same-frequency vibration component of the rotor is obtained
Then, when the rotor generates obvious forward whirling motion, namely near the critical rotating speed, the rotor excited by the unbalanced excitation force moves; and the centroid vector
Advance in
At about 90 degrees, embodiments of the present invention may be directly coupled to
Rotated 90 degrees and multiplied by a constant ksyncObtaining vibration damping force
The vibration suppression force is opposite to the unbalanced excitation force in direction, the excitation effect of the vibration suppression force can be effectively suppressed, and the critical vibration is attenuated.
Specifically, the synchronous damping diagram is shown in FIG. 10, where ε is the convergence factor, where N isfThe structure is shown in FIG. 11, NsThe structure is shown in fig. 12. In FIG. 12, ksFor synchronous damping gain, θ is the lead phase. k is a radical ofsCan be determined by theoretical analysis, simulation or experiment; theoretically, when theta is 90 degrees, the optimal synchronous damping can be obtained, and at the moment, the synchronous electromagnetic force is 90 degrees ahead of the rotor vortex motion displacement vector, so that the pure damping effect is achieved.
When the optimal synchronous damping effect is achieved, the same-frequency control current output by the controller is almost 0, and N issFIG. 13 shows the relationship between the output synchronous damping current and the vibration displacement, where the solid line represents the vibration displacement in a certain radial degree of freedom of a certain supercritical rotor when the rotor is operated at a critical speed, and the dotted line represents the corresponding NsAnd outputting synchronous current, and multiplying the current value by the electromagnet force current coefficient to obtain the corresponding synchronous control force. It can be seen that the dotted line is ahead of the solid line90 degrees, the effect of pure damping force is achieved for vibration displacement by the electromagnetic force corresponding to the dotted line. Thereby effectively suppressing critical vibration of the rotor.
In summary, aiming at the problem that the magnetic bearing controller provides damping for the critical vibration of the rotor when the magnetic bearing rotor runs in a high-speed supercritical state, the embodiment of the invention adopts the synchronous control principle to eliminate the same-frequency control current of the output channel of the controller, and replaces the same-frequency control current with the electromagnetic force which is directly generated by the synchronous damping channel and leads the rotor to carry out 90-degree eddy motion displacement to act on the rotor so as to restrain the critical vibration of the rotor; the electromagnetic force is advanced by 90 degrees in advance of the rotor whirl, which is essentially equivalent to obtaining pure damping force for the rotor whirl, so that high electromagnetic force utilization efficiency can be obtained. Therefore, the synchronous damping current is used for replacing the same-frequency output current of the asynchronous controller, so that the negative effect caused by overhigh gain of the traditional supercritical controller can be avoided, the electromagnetic damping force aiming at the critical vortex motion of the rotor can be generated more efficiently, and the utilization efficiency of the electromagnetic force is effectively improved.
According to the synchronous damping method provided by the embodiment of the invention, the synchronous damping current is used for replacing the same-frequency output current of the controller, so that the negative effect caused by overhigh gain of the traditional supercritical controller can be effectively avoided, and the electromagnetic damping force aiming at the critical vortex motion of the rotor can be generated more efficiently, thereby effectively improving the utilization efficiency of the electromagnetic force; in addition, the critical vortex motion damping is provided by the control force generated by the original magnetic bearing controller (asynchronous), and is provided by the synchronous damping force instead, so that the design difficulty of the magnetic bearing supercritical controller is effectively reduced.
Next, a synchronous damping device proposed according to an embodiment of the present invention is described with reference to the accompanying drawings.
FIG. 14 is a block schematic diagram of a synchronous damping device according to an embodiment of the present invention.
As shown in fig. 14, the synchronous damping device 10 includes: a detection module 100, a filtering module 200 and a control module 300.
The detection module 100 is configured to detect a real-time rotor displacement signal and a phase discrimination signal; the filtering module 200 is configured to perform adaptive filtering on the real-time displacement signal by using the phase-discriminated signal, so as to extract a co-frequency vibration component of the rotor from the real-time displacement signal; the control module 300 is configured to amplify and perform vector transformation on the same-frequency vibration components to output a synchronous damping signal in a direction opposite to a whirling speed of the rotor, and generate a synchronous damping force according to the synchronous damping signal to suppress critical vibration of the rotor through the synchronous damping force.
Further, in an embodiment of the present invention, the method further includes: and the superposition module is used for superposing the synchronous anti-phase shift signal output by the self-adaptive filtering and the real-time shift signal so as to filter the synchronous shift.
Further, in an embodiment of the present invention, the control module 300 is further configured to rotate the amplified and vector-transformed same-frequency vibration component by a first preset angle, and obtain the synchronous damping signal according to a product of the rotated vector same-frequency vibration component and a preset coefficient.
Further, in an embodiment of the present invention, the control module 300 is further configured to, before amplifying and vector-transforming the same-frequency vibration components, obtain a mass eccentricity vector and a displacement eccentricity vector, and calculate an angle of the mass eccentricity vector leading the displacement eccentricity vector, wherein the leading angle is estimated according to a modal circle method in rotor dynamics, or the leading angle is estimated according to a difference between a current rotational speed and a critical rotational speed; and judging whether the advance angle is larger than a critical angle or not, and if so, determining that the rotating speed of the rotor is at the critical rotating speed.
Further, in an embodiment of the present invention, when the rotation speed of the rotor is at the critical rotation speed, the first preset angle may be 90 degrees.
It should be noted that the foregoing explanation of the embodiment of the synchronous damping method is also applicable to the synchronous damping device of the embodiment, and is not repeated herein.
According to the synchronous damping device provided by the embodiment of the invention, the synchronous damping current is used for replacing the same-frequency output current of the controller, so that the negative effect caused by overhigh gain of the traditional supercritical controller can be effectively avoided, the electromagnetic damping force aiming at the critical vortex motion of the rotor can be generated more efficiently, and the electromagnetic force utilization efficiency can be effectively improved; in addition, the critical vortex motion damping is provided by the control force generated by the original magnetic bearing controller (asynchronous), and is provided by the synchronous damping force instead, so that the design difficulty of the magnetic bearing supercritical controller is effectively reduced.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.
Claims (10)
1. A synchronous damping method, comprising the steps of:
detecting a rotor real-time displacement signal and a phase discrimination signal;
carrying out self-adaptive filtering on the real-time displacement signal by using the phase discrimination signal so as to extract a same-frequency vibration component of the rotor from the real-time displacement signal; and
amplifying and vector-converting the same-frequency vibration components to output a synchronous damping signal opposite to the direction of the vortex speed of the rotor, and generating a synchronous damping force according to the synchronous damping signal to suppress the critical vibration of the rotor through the synchronous damping force.
2. The method of claim 1, further comprising:
and superposing the synchronous reverse phase shift signal output by the self-adaptive filtering with the real-time displacement signal to filter out synchronous displacement.
3. The method of claim 1, wherein outputting a synchronous damping signal in a direction opposite to a rotor whirl velocity comprises:
rotating the amplified same-frequency vibration component subjected to vector transformation by a first preset angle;
and obtaining the synchronous damping signal according to the product of the rotated vector same-frequency vibration component and a preset coefficient.
4. The method according to claim 3, before amplifying and vector-transforming the same-frequency vibration components, further comprising:
acquiring a mass eccentricity vector and a displacement eccentricity vector, and calculating an angle of the mass eccentricity vector ahead of the displacement eccentricity vector, wherein the advance angle is estimated according to a difference value between the current rotating speed and a critical rotating speed;
and judging whether the advance angle is larger than a critical angle or not, and if so, determining that the rotating speed of the rotor is at the critical rotating speed.
5. The method of claim 4, wherein the first predetermined angle is 90 degrees when the rotational speed of the rotor is at a critical rotational speed.
6. A synchronous damping device, comprising:
the detection module is used for detecting a rotor real-time displacement signal and a phase discrimination signal;
the filtering module is used for carrying out self-adaptive filtering on the real-time displacement signal by utilizing the phase discrimination signal so as to extract a same-frequency vibration component of the rotor from the real-time displacement signal; and
and the control module is used for amplifying and vector-converting the same-frequency vibration components to output a synchronous damping signal opposite to the direction of the vortex speed of the rotor, and generating a synchronous damping force according to the synchronous damping signal to inhibit the critical vibration of the rotor through the synchronous damping force.
7. The apparatus of claim 6, further comprising:
and the superposition module is used for superposing the synchronous anti-phase shift signal output by the self-adaptive filtering and the real-time shift signal so as to filter out synchronous shift.
8. The apparatus according to claim 6, wherein the control module is further configured to rotate the amplified and vector-transformed co-frequency vibration component by a first preset angle, and obtain the synchronous damping signal according to a product of the rotated vector co-frequency vibration component and a preset coefficient.
9. The device of claim 8, wherein the control module is further configured to obtain a mass eccentricity vector and a displacement eccentricity vector before amplifying and vector transforming the co-frequency vibration components, and calculate an angle at which the mass eccentricity vector leads the displacement eccentricity vector, wherein the lead angle is estimated according to a difference between a current rotation speed and a critical rotation speed; and judging whether the advance angle is larger than a critical angle or not, and if so, determining that the rotating speed of the rotor is at a critical rotating speed.
10. The apparatus of claim 9, wherein the first predetermined angle is 90 degrees when the rotational speed of the rotor is at a critical rotational speed.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101325335A (en) * | 2008-07-24 | 2008-12-17 | 清华大学 | Hyposynchronous damped control system |
| CN102425563A (en) * | 2011-12-08 | 2012-04-25 | 北京中科科仪技术发展有限责任公司 | Method and system for synchronously inhibiting subcritical vibration of rotor of magnetic suspension molecular pump |
| JP6300040B2 (en) * | 2015-11-12 | 2018-03-28 | 株式会社サンセイアールアンドディ | Game machine |
| CN112511054A (en) * | 2019-09-13 | 2021-03-16 | 通用电气公司 | Method and system for rotor stabilization |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JPH01206115A (en) * | 1988-02-12 | 1989-08-18 | Toshiba Corp | Magnetic bearing device |
| JP2565438B2 (en) * | 1991-09-20 | 1996-12-18 | 株式会社日立製作所 | Electromagnetic bearing controller |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101325335A (en) * | 2008-07-24 | 2008-12-17 | 清华大学 | Hyposynchronous damped control system |
| CN102425563A (en) * | 2011-12-08 | 2012-04-25 | 北京中科科仪技术发展有限责任公司 | Method and system for synchronously inhibiting subcritical vibration of rotor of magnetic suspension molecular pump |
| JP6300040B2 (en) * | 2015-11-12 | 2018-03-28 | 株式会社サンセイアールアンドディ | Game machine |
| CN112511054A (en) * | 2019-09-13 | 2021-03-16 | 通用电气公司 | Method and system for rotor stabilization |
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