阅读说明：本技术 一种磁悬浮轴承系统中转子振动抑制系统及方法 (Rotor vibration suppression system and method in magnetic suspension bearing system ) 是由 朱益利 于建英 李渊 张恒 于 2021-08-10 设计创作，主要内容包括：本发明属于磁悬浮轴承技术领域,具体涉及一种磁悬浮轴承系统中转子振动抑制系统及方法,当转子受到干扰力时,转子扰动补偿观测器接收转子振动位移信号、转子振动加速度信号后,发送转子振动抑制补偿控制信号,再通过功率放大器调节控制电流,提供电磁力；当基座受到干扰力时,基座加速度前馈补偿器接收基座振动加速度信号后,发送基座加速度前馈补偿信号,再由位置控制器提供参考位移；当磁悬浮轴承系统失控时,切断位置误差控制通道,加入失稳后转子振动抑制控制信号,抑制转子在保护轴承中产生全间隙涡动；同时转子扰动补偿观测器发送转子振动抑制补偿控制信号,通过功率放大器调节磁悬浮轴承的控制电流,提供电磁力。(The invention belongs to the technical field of magnetic suspension bearings, and particularly relates to a system and a method for suppressing rotor vibration in a magnetic suspension bearing system, wherein when a rotor is subjected to interference force, a rotor disturbance compensation observer receives a rotor vibration displacement signal and a rotor vibration acceleration signal, then sends a rotor vibration suppression compensation control signal, and adjusts a control current through a power amplifier to provide electromagnetic force; when the base is subjected to interference force, the base acceleration feedforward compensator sends a base acceleration feedforward compensation signal after receiving a base vibration acceleration signal, and then the position controller provides reference displacement; when the magnetic suspension bearing system is out of control, cutting off the position error control channel, adding a destabilized rotor vibration suppression control signal, and suppressing the rotor from generating full-gap whirling in the protection bearing; and meanwhile, the rotor disturbance compensation observer sends a rotor vibration suppression compensation control signal, and the control current of the magnetic suspension bearing is adjusted through the power amplifier to provide electromagnetic force.)

1. A system for suppressing rotor vibration in a magnetic bearing system, comprising: the device comprises a magnetic suspension bearing system, a displacement sensor, a base acceleration feedforward compensator, a rotor disturbance compensation observer, a notch filter, a position controller and a power amplifier;

the displacement sensor is used for detecting the rotor displacement; adding two differentiating circuits and a filtering link into a conditioning circuit of the displacement sensor, and differentiating the rotor vibration displacement signal twice to obtain a rotor vibration acceleration signal;

the rotor disturbance compensation observer is used for receiving the rotor vibration displacement signal and the rotor vibration acceleration signal and sending a rotor vibration suppression compensation control signal to the power amplifier;

the power amplifier is used for adjusting the control current of the magnetic suspension bearing;

the base acceleration feedforward compensator is used for receiving a base vibration acceleration signal and sending a base acceleration feedforward compensation signal to the position controller;

the position controller is used for providing compensation displacement for the displacement of the base and sending a position error control signal to the power amplifier;

the notch filter is used for extracting a disturbance signal with the same frequency as the rotation frequency of the rotor.

2. A system for suppressing rotor vibration in a magnetic suspension bearing system as claimed in claim 1, wherein: the device also comprises a rotor stress estimation module and an electromagnetic force estimation module, wherein the rotor stress estimation module receives a rotor vibration acceleration signal, and the electromagnetic force estimation module receives a control signal; and the rotor stress estimation module and the electromagnetic force estimation module are used for evaluating the vibration suppression effect of the rotor in real time and giving out an early warning signal.

3. A method for suppressing a rotor vibration suppression system in a magnetic suspension bearing system according to claim 1, characterized in that:

when the rotor is subjected to external interference force, a position error control channel is opened, the rotor disturbance compensation observer receives a rotor vibration displacement signal and a rotor vibration acceleration signal and then sends a rotor vibration suppression compensation control signal, the control current of the magnetic suspension bearing is adjusted through a power amplifier, electromagnetic force opposite to the direction of the external interference force is provided, and rotor vibration is suppressed;

when the base is subjected to external interference force, a position error control channel is opened, the base acceleration feedforward compensator sends a base acceleration feedforward compensation signal after receiving a base vibration acceleration signal, and the position controller provides reference displacement for compensating the base vibration displacement to inhibit the rotor vibration;

when the magnetic suspension bearing system is out of control, cutting off the position error control channel, adding a destabilized rotor vibration suppression control signal, and suppressing the rotor from generating full-gap whirling in the protection bearing; meanwhile, the rotor disturbance compensation observer sends a rotor vibration suppression compensation control signal, the control current of the magnetic suspension bearing is adjusted through the power amplifier, electromagnetic force opposite to the direction of external interference force is provided, and rotor vibration is suppressed; when the magnetic suspension bearing system is controllable, a position error control channel is opened, and a rotor vibration suppression control signal after instability is cut off to enable the rotor to be suspended again;

the position error control path includes: the displacement of the rotor when the rotor and the base are not disturbed is differed from the set suspension position quantity to obtain an error signal I; filtering disturbance signals in the error signal I, which have the same rotation frequency as the rotor, to obtain an error signal II; and after receiving the second error signal, the position controller sends a position error control signal to the power amplifier, and the power amplifier adjusts the control current of the magnetic suspension bearing to ensure that the rotor is stably suspended in the middle of the stator and rotates around the inertia main shaft of the rotor.

4. The suppression method according to claim 3, characterized in that: the device also comprises a rotor stress estimation module for receiving a rotor vibration acceleration signal and an electromagnetic force estimation module for receiving a control signal; the rotor stress estimation module and the electromagnetic force estimation module are used for evaluating the vibration suppression effect of the rotor in real time and giving out an early warning signal; when the rotor stress estimation module evaluates that the rotor suspension effect and the anti-interference capability are poor but the rotor is not unstable, the compensation controllability is continuously evaluated; and when the electromagnetic force estimation module finds that the change rate of the compensation electromagnetic force is greater than the maximum change rate of the electromagnetic force which can be responded by the magnetic suspension bearing, or the expected current change rate of a control signal required by the compensation force is greater than the maximum current change rate which can be responded by the power amplifier, an early warning signal is given.

5. The suppression method according to claim 4, characterized in that: and the rotor stress estimation module is used for evaluating whether the magnetic suspension bearing system is controllable.

6. The suppression method according to claim 3, characterized in that: the rotor displacement is measured by a displacement sensor.

7. The suppression method according to claim 6, characterized in that: the rotor vibration acceleration signal is obtained by adding two differentiating circuits and a filtering link in a conditioning circuit of the displacement sensor and performing twice differentiation on the rotor vibration displacement signal.

8. The suppression method according to claim 3, characterized in that: the disturbance signal at the same frequency as the rotor rotation frequency is extracted by a notch filter.

9. The suppression method according to claim 3, characterized in that: and setting a time node, and cutting off the magnetic suspension bearing support and the motor drive when the rotor is not resuspended within the set time.

Technical Field

The invention belongs to the technical field of magnetic suspension bearings, and particularly relates to a system and a method for suppressing rotor vibration in a magnetic suspension bearing system.

Background

The magnetic suspension bearing is a novel bearing which realizes non-contact by utilizing electromagnetic force and is often applied to occasions with high rotor rotating speed. At present, a magnetic suspension bearing control system basically adopts a control strategy based on a rotor position error, namely, a displacement sensor is used for detecting real-time vibration displacement of a rotor, the real-time vibration displacement is compared with reference displacement to obtain a displacement error, and the displacement error is eliminated by corresponding electromagnetic force generated by a controller, a power amplifier and a magnetic suspension bearing stator.

In the current control strategy, when a high-speed rotating rotor supported by a magnetic suspension bearing is acted by an external interference force, the vibration acceleration of the rotor is firstly generated and is reflected on the vibration displacement of the rotor through twice integration of time, and only when the vibration displacement of the rotor is reflected, the displacement error can be controlled by a controller, so that certain hysteresis exists. The hysteresis makes the rotor inevitably produce corresponding vibration displacement after the disturbance force is applied, as shown in fig. 1 and 2, which greatly limits the application of the magnetic suspension bearing in some occasions requiring the rotor to have higher position control precision, such as the magnetic suspension motorized spindle used in high-grade numerical control machine tools. When the high-speed rotating rotor supported by the magnetic suspension bearing is subjected to an excessive external interference force, the rotor can be caused to collide with a protective bearing which is arranged in the magnetic suspension bearing system and used for temporarily supporting the rotor and protecting the safety of the system, the collision force between the rotor and the protective bearing can enable the rotor to enter a nonlinear motion state, and a magnetic suspension bearing control system with hysteresis cannot recover the rotor to re-suspend, namely control instability is caused, as shown in fig. 3 and 4, so that the stator and the rotor can be damaged. When the base is subjected to external interference force, the base is firstly vibrated, so that the relative position between the magnetic suspension bearing stator, particularly between the displacement sensor and the rotor is changed, the change of a feedback signal of the displacement sensor can cause the vibration of the rotor, and excessive disturbance can also cause instability of a control system.

The above problems exist mainly because the position error control strategy of the conventional magnetic suspension bearing system has hysteresis and does not have the capability of rapidly suppressing the rotor vibration after the base displacement compensation and control instability. In the prior art, for the vibration suppression research of a rotor in a magnetic suspension bearing system caused by interference force, the compensation force observed only based on a displacement signal has larger error (greatly influenced by sampling frequency and signal-to-noise ratio), and the accurate real-time compensation of random interference force is difficult to realize; for the research on the resuspension of the system after the instability caused by the interference force, the magnetic suspension bearing cannot provide proper active restraining force in time due to the large error in the analysis based on the rotor displacement, cannot rapidly reduce the impact and the vibration of the rotor, and is difficult to rapidly realize the resuspension of the magnetic suspension bearing system.

Disclosure of Invention

In view of the above-mentioned shortcomings, the present invention provides a system and method for suppressing rotor vibration in a magnetic suspension bearing system.

The invention provides the following technical scheme:

a rotor vibration suppression system in a magnetic bearing system, comprising: the device comprises a magnetic suspension bearing system, a displacement sensor, a base acceleration feedforward compensator, a rotor disturbance compensation observer, a notch filter, a position controller and a power amplifier;

the displacement sensor is used for detecting the rotor displacement; adding two differentiating circuits and a filtering link into a conditioning circuit of the displacement sensor, and differentiating the rotor vibration displacement signal twice to obtain a rotor vibration acceleration signal;

the rotor disturbance compensation observer is used for receiving the rotor vibration displacement signal and the rotor vibration acceleration signal and sending a rotor vibration suppression compensation control signal to the power amplifier;

the power amplifier is used for adjusting the control current of the magnetic suspension bearing;

the base acceleration feedforward compensator is used for receiving a base vibration acceleration signal and sending a base acceleration feedforward compensation signal to the position controller;

the position controller is used for providing compensation displacement for the displacement of the base and sending a position error control signal to the power amplifier;

the notch filter is used for extracting a disturbance signal with the same frequency as the rotation frequency of the rotor.

The device also comprises a rotor stress estimation module and an electromagnetic force estimation module, wherein the rotor stress estimation module receives a rotor vibration acceleration signal, and the electromagnetic force estimation module receives a control signal; and the rotor stress estimation module and the electromagnetic force estimation module are used for evaluating the vibration suppression effect of the rotor in real time and giving out an early warning signal.

A method for inhibiting rotor vibration in a magnetic suspension bearing system,

when the rotor is subjected to external interference force, a position error control channel is opened, the rotor disturbance compensation observer receives a rotor vibration displacement signal and a rotor vibration acceleration signal and then sends a rotor vibration suppression compensation control signal, the control current of the magnetic suspension bearing is adjusted through a power amplifier, electromagnetic force opposite to the direction of the external interference force is provided, and rotor vibration is suppressed;

when the base is subjected to external interference force, a position error control channel is opened, the base acceleration feedforward compensator sends a base acceleration feedforward compensation signal after receiving a base vibration acceleration signal, and the position controller provides reference displacement for compensating the base vibration displacement to inhibit the rotor vibration;

when the magnetic suspension bearing system is out of control, cutting off the position error control channel, adding a destabilized rotor vibration suppression control signal, and suppressing the rotor from generating full-gap whirling in the protection bearing; meanwhile, the rotor disturbance compensation observer sends a rotor vibration suppression compensation control signal, the control current of the magnetic suspension bearing is adjusted through the power amplifier, electromagnetic force opposite to the direction of external interference force is provided, and rotor vibration is suppressed; when the magnetic suspension bearing system is controllable, a position error control channel is opened, and a rotor vibration suppression control signal after instability is cut off to enable the rotor to be suspended again;

the position error control path includes: the displacement of the rotor when the rotor and the base are not disturbed is differed from the set suspension position quantity to obtain an error signal I; filtering disturbance signals in the error signal I, which have the same rotation frequency as the rotor, to obtain an error signal II; and after receiving the second error signal, the position controller sends a position error control signal to the power amplifier, and the power amplifier adjusts the control current of the magnetic suspension bearing to ensure that the rotor is stably suspended in the middle of the stator and rotates around the inertia main shaft of the rotor.

The device also comprises a rotor stress estimation module for receiving a rotor vibration acceleration signal and an electromagnetic force estimation module for receiving a control signal; and the rotor stress estimation module and the electromagnetic force estimation module are used for evaluating the vibration suppression effect of the rotor in real time and giving out an early warning signal. When the rotor stress estimation module evaluates that the rotor suspension effect and the anti-interference capability are poor but the rotor is not unstable, the compensation controllability is continuously evaluated; and when the electromagnetic force estimation module finds that the change rate of the compensation electromagnetic force is greater than the maximum change rate of the electromagnetic force which can be responded by the magnetic suspension bearing, or the expected current change rate of a control signal required by the compensation force is greater than the maximum current change rate which can be responded by the power amplifier, an early warning signal is given.

And the rotor stress estimation module is used for evaluating whether the magnetic suspension bearing system is controllable.

The rotor displacement is measured by a displacement sensor.

The rotor vibration acceleration signal is obtained by adding two differentiating circuits and a filtering link in a conditioning circuit of the displacement sensor and performing twice differentiation on the rotor vibration displacement signal.

The disturbance signal at the same frequency as the rotor rotation frequency is extracted by a notch filter.

And setting a time node, and cutting off the magnetic suspension bearing support and the motor drive when the rotor is not resuspended within the set time.

The invention has the beneficial effects that:

the invention can enable the magnetic suspension bearing to provide the electromagnetic force opposite to the interference force in time to inhibit the vibration acceleration of the rotor when the rotor is subjected to the external interference force, so as to avoid the occurrence of large-amplitude vibration displacement of the rotor in the later period; when the magnetic suspension bearing stator base is subjected to external interference force, compensation reference displacement is provided in time, and the rotor is restrained from vibrating greatly; after the magnetic suspension bearing is unstable due to strong impact, the large-amplitude high-frequency vibration of the rotor is quickly inhibited. The invention can compensate the rotor in time when the rotor is subjected to external small-amplitude low-frequency interference force, and the rotor amplitude inhibition effect reaches more than 70 percent; when the base is subjected to a small-amplitude low-frequency interference force, compensation reference displacement can be provided in time, and the rotor amplitude suppression effect reaches more than 70%; when the rotor is subjected to external large-amplitude high-frequency interference force, the possibility of instability of a magnetic suspension bearing control system can be reduced to a certain extent, and after the instability occurs, the rotor can be quickly restrained from vibrating greatly, so that the magnetic suspension bearing system can be helped to realize resuspension under the condition that the speed of the rotor is not reduced.

Drawings

FIG. 1 is a graph of rotor vibration displacement with small disturbance forces affecting rotor vibration;

FIG. 2 is a diagram of the rotor axis locus when small disturbance force affects the rotor vibration;

FIG. 3 is a graph of rotor vibration displacement as a large disturbance force affects rotor vibration;

FIG. 4 is a graph of rotor axis trajectories when large disturbance forces affect rotor vibration;

fig. 5 is a control flow diagram of the present invention.

Labeled as: the control method comprises the steps of rotor displacement 101, a base acceleration feedforward compensation signal 102, a set levitation displacement 103, a disturbance signal 104 with the same rotor rotation frequency, a second error signal 105, a post-instability rotor vibration suppression control signal 106, a position error control signal 107, a rotor vibration suppression compensation control signal 108, a power amplifier 109, a control current 110, a current stiffness coefficient 111, a rotor electromagnetic force 112, a rotor disturbance force 113, a base vibration acceleration signal 114, a displacement stiffness coefficient 115, a displacement sensor 116, a first differential circuit 117, a second differential circuit 118, a rotor acceleration signal transfer function 119, a rotor vibration acceleration signal 120 and a position controller 121.

Detailed Description

As shown in fig. 5, a rotor vibration suppression system in a magnetic suspension bearing system includes: the device comprises a magnetic suspension bearing system, a displacement sensor, a base acceleration feedforward compensator, a rotor disturbance compensation observer, a notch filter, a position controller and a power amplifier; the displacement sensor is used for detecting the rotor displacement; adding two differentiating circuits and a filtering link into a conditioning circuit of the displacement sensor, and differentiating the rotor vibration displacement signal twice to obtain a rotor vibration acceleration signal; the rotor disturbance compensation observer is used for receiving the rotor vibration displacement signal and the rotor vibration acceleration signal and sending a rotor vibration suppression compensation control signal to the power amplifier; the power amplifier is used for adjusting the control current of the magnetic suspension bearing; the base acceleration feedforward compensator is used for receiving a base vibration acceleration signal and sending a base acceleration feedforward compensation signal to the position controller; the position controller is used for providing compensation displacement for the displacement of the base and sending a position error control signal to the power amplifier; the notch filter is used for extracting a disturbance signal with the same frequency as the rotation frequency of the rotor. The device also comprises a rotor stress estimation module and an electromagnetic force estimation module, wherein the rotor stress estimation module receives a rotor vibration acceleration signal, and the electromagnetic force estimation module receives a control signal; and the rotor stress estimation module and the electromagnetic force estimation module are used for evaluating the vibration suppression effect of the rotor in real time and giving out an early warning signal.

A method for suppressing rotor vibration in a magnetic suspension bearing system comprises a position error control channel, wherein the position error control channel comprises: the method comprises the steps that the difference between rotor displacement 101 when a rotor and a base are not disturbed and set suspension position quantity 103 is obtained to obtain an error signal I; filtering a disturbance signal 104 in the error signal I, which has the same rotation frequency as the rotor, to obtain an error signal II 105; after receiving the second error signal 105, the position controller 121 sends a position error control signal 107 to the power amplifier 109, and the power amplifier 109 adjusts the control current 110 of the magnetic suspension bearing, so that the rotor is stably suspended in the middle of the stator and rotates around the inertia spindle of the stator, thereby improving the stability of the system. Therein, the rotor displacement 101 is measured by a displacement sensor 116 and the disturbance signal 104 at the same frequency as the rotor rotation frequency is extracted by a notch filter.

When the rotor is subjected to an external interference force, a position error control channel is opened, namely the power amplifier 109 receives a position error control signal 107, the rotor disturbance compensation observer receives a rotor vibration displacement signal and a rotor vibration acceleration signal 120 and then sends a rotor vibration suppression compensation control signal 108, and the power amplifier 109 adjusts a control current 110 of the magnetic suspension bearing to provide an electromagnetic force opposite to the direction of the external interference force so as to suppress rotor vibration. The rotor vibration acceleration signal 120 is obtained by adding two differentiating circuits and a filtering element to a conditioning circuit of the displacement sensor 116 to differentiate the displacement signal twice. The two differentiating circuits are differentiating circuit one 117 and differentiating circuit two 118.

When the base receives external interference force, a position error control channel is opened, namely the power amplifier 109 receives a position error control signal 107, the base acceleration feedforward compensator receives a base vibration acceleration signal 114 and then sends a base acceleration feedforward compensation signal 102, and the position controller 121 provides reference displacement for compensating base vibration displacement to timely compensate large vibration which may occur to the rotor.

A rotor stress estimation module for receiving the rotor vibration acceleration signal 120 and an electromagnetic force estimation module for receiving a control signal are also arranged; and the rotor stress estimation module and the electromagnetic force estimation module are used for evaluating the vibration suppression effect of the rotor in real time and giving out an early warning signal. When the rotor stress estimation module evaluates that the rotor suspension effect and the anti-interference capability are poor but the rotor is not unstable, the compensation controllability is continuously evaluated; and when the electromagnetic force estimation module finds that the change rate of the compensation electromagnetic force is greater than the maximum change rate of the electromagnetic force which can be responded by the magnetic suspension bearing, or the expected current change rate of a control signal required by the compensation force is greater than the maximum current change rate which can be responded by the power amplifier, an early warning signal is given.

When the magnetic suspension bearing system is out of control, cutting off a position error control channel, namely cutting off a position error control signal 107, and adding a destabilized rotor vibration suppression control signal 106 to suppress the rotor from generating full-gap vortex motion in the protection bearing; meanwhile, the rotor disturbance compensation observer sends a rotor vibration suppression compensation control signal 108, adjusts a control current 110 of the magnetic suspension bearing through a power amplifier 109, provides an electromagnetic force with the direction opposite to that of an external interference force, suppresses rotor vibration, and thus rapidly suppresses rotor large-amplitude high-frequency vibration; when the rotor stress estimation module evaluates that the magnetic suspension bearing system is controllable, a position error control channel is started, namely a power amplifier 109 receives a position error control signal 107, and a rotor vibration suppression control signal 106 after instability is cut off, so that the rotor is suspended again. Meanwhile, a time node can be set, and when the rotor is not resuspended within the set time, the magnetic suspension bearing support and the motor drive are cut off, so that the safety of the system is ensured.

Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.