WO2015188669A1 - Magnetic bearing system control method, control device and air conditioner - Google Patents

Abstract

A magnetic bearing system control method, comprising: obtaining a displacement signal of a rotor in a magnetic bearing system; determining in the displacement signal a sinusoidal component at the same frequency with the rotational speed; compensating the displacement signal with a compensation signal, the compensation signal being a product of the sinusoidal component and an optimal vortex motion separation weighted coefficient; generating a control signal based on the current compensated displacement signal so as to control a power amplifier to adjust the exciting current flowing through the bearing coil in the magnetic bearing. The control method can reduce control signal fluctuation and improve the levitation precision and stability of a rotor. In addition, the present invention also relates to a corresponding control device and air conditioner.

Description

Control method, control device and air conditioner of magnetic suspension bearing system

This application claims priority to Chinese Patent Application No. 201410259063.9, entitled "Control Method, Control Device and Air Conditioning of Magnetic Bearing System" on June 11, 2014, the entire contents of which are incorporated by reference. In this application.

Technical field

The invention belongs to the technical field of magnetic suspension bearings, and particularly relates to a control method, a control device and an air conditioner of a magnetic suspension bearing system.

Background technique

The magnetic suspension bearing system is a new type of bearing system. During its operation, the rotor is suspended in the air by magnetic force, so that there is no mechanical contact between the rotor and the stator, which has the advantages of low wear, low energy consumption and low noise. At present, magnetic suspension bearing systems are mostly used in compressors, that is, magnetic suspension compressors. During the operation of the magnetic suspension bearing system, the eccentricity of the rotor's mass will cause vibration, which will affect the suspension accuracy and stability of the rotor. Among them, the suspension accuracy characterizes the amount of displacement of the rotor from the center position.

How to control the operation process of the magnetic suspension bearing system in order to improve its suspension accuracy and stability is a problem faced by those skilled in the art.

Summary of the invention

In view of the above, an object of the present invention is to provide a control method and a control device for a magnetic suspension bearing system to realize control of a magnetic suspension bearing system and improve suspension accuracy and stability of the rotor. In addition, the present invention also discloses an air conditioner.

To achieve the above object, the present invention provides the following technical solutions:

The invention discloses a control method of a magnetic suspension bearing system, and the control method comprises:

Obtaining a displacement signal of the rotor in the magnetic suspension bearing system;

Determining a sinusoidal component of the displacement signal that is at the same frequency as the rotational speed;

Compensating the displacement signal with a compensation signal, the compensation signal being the sinusoidal component The product of the optimal eddy separation weighting coefficients;

A control signal is generated based on the currently compensated displacement signal to control the power amplifier to adjust the excitation current flowing through the bearing coil in the magnetic suspension bearing.

Preferably, the initial value of the eddy separation weighting coefficient is 0 or 1, and the operation of determining the optimal eddy separation weighting coefficient comprises:

Determining a suspension accuracy of the rotor after compensation based on a current eddy separation weighting coefficient;

Determining whether the currently acquired suspension accuracy of the rotor is higher than the suspension accuracy of the rotor obtained in the previous week;

If yes, adjusting the eddy separation weighting coefficient along the preset direction by using the first step length, and returning to performing the step of determining the suspension accuracy of the rotor after the compensation based on the current eddy separation weighting coefficient;

If not, the eddy separation weighting coefficient used in the previous week is determined as the optimal eddy separation weighting coefficient.

Preferably, the first step length is between 0.001 and 0.01.

Preferably, the initial value of the eddy separation weighting coefficient is a first value greater than 0 and less than 1, and the operation of determining the optimal eddy separation weighting coefficient comprises:

Determining a suspension accuracy of the rotor after compensation based on a current eddy separation weighting coefficient;

Determining whether the currently acquired suspension accuracy of the rotor is higher than the suspension accuracy of the rotor obtained in the previous week;

If yes, adjusting the eddy separation weighting coefficient in the first direction by using the second step, and returning to performing the step of determining the suspension accuracy of the rotor after the compensation based on the current eddy separation weighting coefficient;

If not, determining the eddy separation weighting coefficient used in the previous week as the first eddy separation weighting coefficient, adjusting the eddy separation weighting coefficient to a second value, and the second value is located in the first In the second direction of the value, determining whether the suspension accuracy of the rotor after the compensation is based on the eddy separation weighting coefficient of the second value is lower than the suspension accuracy after compensation based on the first eddy separation weighting coefficient, and if so, Determining that the first eddy separation weighting coefficient is an optimal eddy separation weighting coefficient; otherwise, adjusting the eddy separation weighting coefficient along the second direction by using a third step until the adjusted eddy separation weighting is performed After the coefficient is compensated, the suspension accuracy of the rotor is lower than that of the previous week. Degree, the eddy separation weighting coefficient used in the previous week is determined as the optimal eddy separation weighting coefficient.

Preferably, the second step and the third step are between 0.001 and 0.01.

The invention also discloses a control device for a magnetic suspension bearing system, comprising:

a displacement signal acquiring unit, configured to acquire a displacement signal of the rotor in the magnetic suspension bearing system;

a sinusoidal component determining unit, configured to determine a sinusoidal component of the displacement signal acquired by the displacement signal acquiring unit and the same frequency as the rotational speed;

a compensation unit, configured to compensate the displacement signal by using a compensation signal, where the compensation signal is a product of the sinusoidal component and an optimal eddy separation weighting coefficient;

a control unit, configured to generate a control signal based on the currently compensated displacement signal to control the power amplifier to adjust an excitation current flowing through the bearing coil in the magnetic suspension bearing;

A weighting coefficient determining unit is configured to determine an optimal eddy separation weighting coefficient.

Preferably, the initial value of the eddy separation weighting coefficient is 0 or 1, and the weighting coefficient determining unit comprises:

a suspension accuracy determining module, configured to determine a suspension accuracy of the rotor after being compensated based on a current eddy separation weighting coefficient;

a first judging module, configured to determine whether the currently acquired suspension accuracy of the rotor is higher than a suspension accuracy of the rotor acquired in a previous period;

a first processing module, configured to: when the determination result of the first determining module is YES, adjust a vortex separation weighting coefficient along a preset direction by using a first step length, and then trigger the levitation precision determining module;

The second processing module is configured to determine, as the determination result of the first determining module is negative, the eddy separation weighting coefficient used in the previous period as the optimal eddy separation weighting coefficient.

Preferably, the initial value of the eddy separation weighting coefficient is a first value greater than 0 and less than 1, and the weighting coefficient determining unit comprises:

a suspension accuracy determining module, configured to determine a suspension accuracy of the rotor after being compensated based on a current eddy separation weighting coefficient;

a first determining module, configured to determine whether the currently acquired suspension accuracy of the rotor is higher than a previous one Suspension accuracy of the rotor obtained during the cycle;

a third processing module, configured to: in the case that the determination result of the first determining module is YES, adjust the eddy separation weighting coefficient in the first direction by using the second step, and then trigger the suspension precision determining module;

a fourth processing module, configured to determine, when the determination result of the first determining module is negative, a vortex separation weighting coefficient used in a previous period as a first eddy separation weighting coefficient, and to vortex separation weighting The coefficient is adjusted to a second value, the second value is located in a second direction of the first value, and then the suspension accuracy determining module is triggered;

a second judging module, configured to determine whether the suspension accuracy of the rotor after being compensated based on the second value-based eddy separation weighting coefficient is lower than a suspension accuracy after being compensated based on the first eddy separation weighting coefficient;

a fifth processing module, configured to determine, in a case that the determination result of the second determining module is YES, that the first eddy separation weighting coefficient is an optimal eddy separation weighting coefficient;

a sixth processing module, configured to adjust, according to the second step, the vortex separation weighting coefficient in the second direction, if the determination result of the second determining module is negative, until the adjusted whirl After the separation weighting coefficient is compensated, the suspension accuracy of the rotor is lower than the suspension precision of the previous week, and the eddy separation weighting coefficient used in the previous week is determined as the optimal eddy separation weighting coefficient.

The invention also discloses an air conditioner comprising a magnetic levitation compressor, the magnetic levitation compressor comprising a magnetic levitation bearing system, the magnetic levitation bearing system comprising: a magnetic levitation bearing, a rotor, a power amplifier, a displacement detecting device and any one of the above control devices.

It can be seen that the beneficial effects of the present invention are: the control method and the control device of the magnetic suspension bearing system disclosed by the present invention, after acquiring the displacement signal of the rotor, determining the sinusoidal component of the current displacement signal and the same frequency as the rotational speed, The product of the sinusoidal component and the optimal eddy separation weighting coefficient is used as a compensation signal to compensate the current displacement signal to reduce or even cancel the periodic interference signal in the displacement signal, thereby reducing the fluctuation component of the control signal and improving the rotor's Suspension accuracy and stability.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description are Some embodiments of the present invention may also be used to obtain other drawings based on these drawings without departing from the art.

1 is a flow chart of a control method of a magnetic suspension bearing system disclosed by the present invention;

2 is a flow chart of a method for determining an optimal eddy separation weighting coefficient in the present invention;

3 is a flow chart of another method for determining an optimal eddy separation weighting coefficient in the present invention;

4 is a schematic block diagram of determining a sinusoidal component of the same frequency as the rotational speed in the displacement signal by using a variable step length LMS method;

Figure 5 is a schematic block diagram of a control process of the magnetic suspension bearing system disclosed in the present invention;

6 is a comparison diagram of effects of a control method disclosed in the present invention on a magnetic suspension bearing system and an existing control method;

7 is a schematic structural view of a control device of the magnetic suspension bearing system disclosed in the present invention;

FIG. 8 is a schematic structural diagram of a weighting coefficient determining unit according to the present invention; FIG.

FIG. 9 is another schematic structural diagram of a weighting coefficient determining unit in the present invention.

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. It is a partial embodiment of the invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

The invention discloses a control method of a magnetic suspension bearing system, which realizes control of a magnetic suspension bearing system and improves suspension precision and stability of the rotor.

Referring to FIG. 1, FIG. 1 is a flow chart of a control method of a magnetic suspension bearing system disclosed by the present invention. The control method includes:

Step S11: Acquire a displacement signal of the rotor in the magnetic suspension bearing system.

The magnetic suspension bearing system mainly includes a magnetic suspension bearing, a rotor, a control device, a power amplifier and a displacement detecting device. During the operation of the magnetic suspension bearing system, the displacement detecting device can detect the displacement of the rotor from the center position and output a displacement signal.

Step S12: determining a sinusoidal component of the displacement signal that is the same frequency as the rotational speed.

Step S13: Compensating the current displacement signal by using a compensation signal, which is a product of the sinusoidal component and the optimal eddy separation weighting coefficient.

The displacement signal detected by the displacement detecting device includes both a periodic interference signal and a random vibration signal (useful signal). The periodic interfering signals in the displacement signal cause fluctuations in the same frequency in the control signal, which ultimately leads to vibration of the rotor. In the invention, the sinusoidal component of the displacement signal and the same speed as the rotational speed is extracted, and a part of the sinusoidal component is used to compensate the displacement signal detected by the displacement sensor, thereby reducing or even canceling the periodic interference signal in the displacement signal, thereby reducing the control. The wave component in the signal improves the suspension accuracy and stability of the rotor.

Step S14: generating a control signal based on the currently compensated displacement signal to control the power amplifier to adjust the excitation current flowing through the bearing coil in the magnetic suspension bearing.

The control device in the magnetic levitation bearing system generates a control signal based on the compensated displacement signal, which is consistent with the prior art process of generating a control signal based on the displacement signal. The control signal generated by the control device is transmitted to the power amplifier in the magnetic suspension bearing system, and the power amplifier amplifies the control signal to adjust the current flowing through the bearing coil in the magnetic suspension bearing system, thereby changing the magnetic force acting on the rotor, and adjusting the rotor Suspended position.

The control method of the magnetic suspension bearing system disclosed by the present invention determines the sinusoidal component of the current displacement signal and the same frequency as the rotational speed after acquiring the displacement signal of the rotor, and compensates the product of the sinusoidal component and the optimal eddy separation weighting coefficient as compensation The signal compensates the current displacement signal to reduce or even cancel the periodic interference signal in the displacement signal, thereby reducing the fluctuation component of the control signal and improving the suspension accuracy and stability of the rotor.

The optimal eddy separation weighting coefficient in the invention is obtained by automatically optimizing the suspension accuracy of the rotor as the optimization target. The operation of determining the optimal eddy separation weighting factor can be carried out for the first time in the magnetic suspension bearing system. Execution at the time of the line can also be performed periodically, for example once a day or once a week. The optimal eddy separation weighting factor can be determined in a variety of ways, as explained below in connection with Figures 2 and 3.

Referring to FIG. 2, FIG. 2 is a flow chart of a method for determining an optimal eddy separation weighting coefficient in the present invention. Wherein, the initial value of the eddy separation weighting coefficient is 0 or 1, and the method comprises:

Step S21: determining the suspension accuracy of the rotor after compensation based on the current eddy separation weighting coefficient.

The suspension accuracy of the rotor characterizes the displacement of the rotor from the center position. When the suspension accuracy of the rotor is high, the distance between the current position of the rotor and its center position is small. When the suspension accuracy of the rotor is low, the current position of the rotor is indicated. The distance between it and its center position is large.

Step S22: It is judged whether the suspension precision of the currently obtained rotor is higher than the suspension precision of the rotor acquired in the previous period, and if yes, step S23 is performed, otherwise, step S24 is performed.

Step S23: adjusting the vortex separation weighting coefficient along the preset direction by using the first step length, and executing step S21.

If the suspension accuracy of the rotor is higher than the suspension accuracy of the rotor obtained in the previous week after the current eddy separation weighting coefficient is compensated, the first step is used to adjust the eddy separation weighting coefficient along the preset direction. Specifically: in the case where the initial value of the vortex separation weighting coefficient is 0, the first step is used to adjust the eddy separation weighting coefficient along the preset direction, specifically by using the first step length to increase the eddy separation weighting coefficient; In the case where the initial value of the dynamic separation weighting coefficient is 1, the first step is used to adjust the eddy separation weighting coefficient along the preset direction, specifically by using the first step length to reduce the eddy separation weighting coefficient.

In the implementation, the first step length can be a fixed value or a variable value. Preferably, the first step is between 0.001 and 0.01.

Step S24: Determine the eddy separation weighting coefficient in the previous week as the optimal eddy separation weighting coefficient.

If the suspension accuracy of the rotor is lower than the suspension accuracy of the rotor obtained in the previous week after compensation based on the current eddy separation weighting coefficient, it indicates that the eddy separation weighting coefficient before the most recent adjustment is the optimal eddy separation. The weighting factor, that is, the eddy separation weighting coefficient used in the previous week is the optimal eddy separation weighting coefficient.

In the method shown in FIG. 2 of the present invention, the initial value of the eddy separation weighting coefficient is 0 or 1, and the eddy separation weighting coefficient is adjusted along the preset direction by the first step length, after each adjustment of the eddy separation weighting coefficient Determine the suspension accuracy of the rotor after compensation based on the adjusted eddy separation weighting coefficient, and determine whether the suspension accuracy is higher than the suspension accuracy of the rotor in the previous week until the suspension accuracy of the rotor is lower than the previous one. For the suspension accuracy, the eddy separation weighting coefficient used in the previous week is determined as the optimal eddy separation weighting coefficient.

Referring to FIG. 3, FIG. 3 is a flow chart of another method for determining an optimal eddy separation weighting coefficient in the present invention. Wherein, the initial value of the eddy separation weighting coefficient is a first value greater than 0 and less than 1, the method comprising:

Step S31: determining the suspension accuracy of the rotor after compensation based on the current eddy separation weighting coefficient.

Step S32: It is judged whether the suspension precision of the currently obtained rotor is higher than the suspension precision of the rotor acquired in the previous period, and if yes, step S33 is performed, otherwise, step S34 is performed.

Step S33: adjusting the eddy separation weighting coefficient in the first direction by using the second step, and performing step S31.

The adjusting the eddy separation weighting coefficient in the first direction by using the second step is specifically: increasing the eddy separation weighting coefficient by using the second step, or reducing the eddy separation weighting coefficient by using the second step.

After adjusting the vortex separation weighting coefficient in the first direction by using the second step length, determining the suspension accuracy of the rotor after compensation based on the adjusted eddy separation weighting coefficient, if the suspension accuracy is higher than the suspension precision of the rotor in the previous week (That is, the suspension accuracy of the rotor after compensation based on the eddy separation weighting coefficient before the last adjustment), and then continue to adjust the eddy separation weighting system along the first direction by using the second step.

Step S34: Determine the eddy separation weighting coefficient used in the previous week as the first eddy separation weighting coefficient, and adjust the eddy separation weighting coefficient to the second value.

Wherein the second value is located in the second direction of the first value. The second direction is opposite to the first direction. When the first direction is to increase the vortex separation weighting coefficient, the second direction is to reduce the eddy separation weighting coefficient, and when the first direction is to reduce the eddy separation weighting coefficient, The second direction is to increase the eddy separation weighting coefficient.

When the suspension accuracy of the rotor is lower than the suspension accuracy of the rotor during the previous week, it indicates that the eddy separation weighting coefficient used in the previous week is the optimal eddy of the eddy separation weighting coefficient from the initial value in the first direction adjustment process. The weighting coefficient is separated, and then the eddy separation weighting coefficient is adjusted to a second value to determine whether there is a better value in the adjustment process of the eddy separation weighting coefficient from the initial value in the second direction.

Step S35: determining whether the suspension accuracy of the rotor after compensating based on the vortex separation weighting coefficient of the second value is lower than the suspension accuracy after compensation based on the first eddy separation weighting factor, and if yes, executing step S36, otherwise, performing steps S37.

Step S36: determining that the first eddy separation weighting coefficient is an optimal eddy separation weighting coefficient.

Step S37: Adjust the eddy separation weighting coefficient in the second direction by using the third step.

Step S38: It is judged whether the suspension accuracy of the rotor after the compensation based on the adjusted eddy separation weighting coefficient is lower than the suspension accuracy of the previous period, and if so, step S39 is performed, otherwise, step S37 is performed.

Step S39: Determine the eddy separation weighting coefficient used in the previous week as the optimal eddy separation weighting coefficient.

After adjusting the eddy separation weighting coefficient to the second value, determining the suspension accuracy of the rotor after compensating based on the eddy separation weighting coefficient of the second value. When the suspension accuracy is lower than the suspension accuracy of the rotor after the compensation based on the first eddy separation weighting coefficient, the first eddy separation weighting coefficient is determined as the optimal eddy separation weighting coefficient. When the suspension accuracy is higher than the suspension accuracy of the rotor after compensation based on the first eddy separation weighting coefficient, the vortex separation weighting coefficient is adjusted along the second direction by the third step until the adjusted eddy separation weighting coefficient is performed. After the compensation, the suspension accuracy of the rotor is lower than that of the previous one week, and the eddy separation weighting coefficient used in the previous week is determined as the optimal eddy separation weighting coefficient, that is, the eddy separation weighting before the last adjustment is weighted. The coefficient is determined as the optimal eddy separation weighting coefficient.

In the implementation, the second step and the third step may be fixed values or variable values. Preferably, the second step and the third step are between 0.001 and 0.01.

In the method shown in FIG. 3 of the present invention, the initial value of the eddy separation weighting coefficient is between 0 and 1, and the eddy separation weighting coefficient is first adjusted in the first direction in the second step to determine the first eddy separation. Weighting coefficient, the first eddy separation weighting coefficient is an optimal whirl in the process of adjusting from the initial value in the first direction Separating the weighting coefficient, and then adjusting the eddy separation weighting coefficient to a second value in the second direction of the initial value, and the suspension accuracy after the rotor is compensated based on the second value is lower than the first eddy separation weighting coefficient When the suspended suspension accuracy is compensated, the first eddy separation weighting coefficient is determined as the optimal eddy separation weighting coefficient, and the suspension accuracy after the rotor is compensated based on the second value is higher than that based on the first eddy separation weighting coefficient In the suspension accuracy, the vortex separation weighting coefficient is adjusted along the second direction in the third step until the suspension accuracy of the rotor is compensated based on the adjusted eddy separation weighting coefficient, and the suspension accuracy is lower than the previous one. The eddy separation weighting coefficient used in one cycle is determined as the optimal eddy separation weighting coefficient.

In the implementation, the variable step size LMS (least mean square) method can be used to determine the sinusoidal component of the rotor's displacement signal at the same frequency as the rotational speed. The principle is shown in Fig. 4.

The displacement signal of the rotor contains both periodic interference signals and random vibration signals (useful signals). e(k) is the displacement signal of the rotor. The reference inputs x ₁ (k) and x ₂ (k) are standard sinusoidal signals of the same period as the interfering signals, and the two signals are 90° out of phase. The purpose of the LMS algorithm is to obtain the values of the weight vectors w ₁ (k) and w ₂ (k) such that the combined output signal y(k) cancels out the periodic interference signal in the original displacement signal e(k), thereby achieving The mean square of the error is the smallest. The output signal y(k) is the sinusoidal component of the displacement signal e(k) at the same frequency as the rotational speed, y(k)=x ₁ (k)*w ₁ (k)+x ₂ (k)*w ₂ (k ). The LMS algorithm changes the gain parameters at each sampling time, which is easier to implement.

The weight vectors w ₁ (k) and w ₂ (k) iteratively search for the optimal weight vector using the steepest descent method, so that the mean square error is minimized. The iterative formula is:

Where μ is a fixed compensation factor. The key to this algorithm lies in the selection of μ. The larger μ is, the faster the system converges, but the bandwidth of the adaptive filter will become larger, which will affect the signal that does not need compensation, or even be filtered out. The stability of the impact, ultimately leading to the divergence of the LMS algorithm. On the other hand, when μ is taken too small, the system convergence speed will be slower, but the performance will be better, and μ can be adjusted by the following formula:

Where f is the rotational frequency of the rotor and α is the weighting factor, the purpose is to increase the influence of the error signal on the variable step size.

The control process of the magnetic suspension bearing system disclosed in the present invention is as shown in FIG. After the applicant applies control to the magnetic suspension bearing system according to the control method disclosed by the present invention, compared with the existing control mode, the fluctuation of the excitation current in the bearing coil is reduced by about 55%, and the suspension accuracy of the rotor is increased by about 30%. 6 is shown.

The above invention discloses a control method of a magnetic suspension bearing system. Accordingly, the present invention also discloses a control device for a magnetic suspension bearing system to implement the control method.

Referring to FIG. 7, FIG. 7 is a schematic structural view of a control device of the magnetic suspension bearing system disclosed in the present invention. The control device includes a displacement signal acquisition unit 1, a sine component determination unit 2, a compensation unit 3, a control unit 4, and a weighting coefficient determination unit 5.

among them:

The displacement signal acquisition unit 1 is configured to acquire a displacement signal of the rotor in the magnetic suspension bearing system. During the operation of the magnetic suspension bearing system, the displacement detecting device can detect the displacement of the rotor from the center position and output a displacement signal, and the displacement signal acquiring unit 1 acquires the signal of the rotor from the displacement detecting device.

The sinusoidal component determining unit 2 is configured to determine a sinusoidal component of the displacement signal acquired by the displacement signal acquiring unit 1 at the same frequency as the rotational speed.

The compensation unit 3 is configured to compensate the displacement signal by using the compensation signal, wherein the compensation signal is the product of the sinusoidal component determined by the sinusoidal component determining unit 2 and the optimal eddy separation weighting coefficient.

The control unit 4 is configured to generate a control signal based on the currently compensated displacement signal to control the power amplifier to adjust the excitation current flowing through the bearing coil in the magnetic suspension bearing.

The weighting coefficient determining unit 5 is configured to determine an optimal eddy separation weighting coefficient.

The control device of the magnetic suspension bearing system disclosed by the present invention, after acquiring the displacement signal of the rotor, Determining the sinusoidal component of the current displacement signal at the same frequency as the rotational speed, and using the product of the sinusoidal component and the optimal eddy separation weighting coefficient as a compensation signal to compensate the current displacement signal to reduce or even cancel the period in the displacement signal The interference signal, thereby reducing the fluctuation component of the control signal, improving the suspension accuracy and stability of the rotor.

The optimal eddy separation weighting coefficient can be determined in various ways, and correspondingly, the weighting coefficient determining unit 5 has a different structure. The following description will be respectively made.

Referring to FIG. 8, FIG. 8 is a schematic structural diagram of a weighting coefficient determining unit according to the present invention. The initial value of the eddy separation weighting coefficient is 0 or 1. The weighting coefficient determining unit includes a floating precision determining module 501, a first determining module 502, a first processing module 503, and a second processing module 504.

among them:

The suspension accuracy determining module 501 is configured to determine a suspension accuracy of the rotor after the compensation based on the current eddy separation weighting coefficient.

The first determining module 502 is configured to determine whether the currently acquired suspension accuracy of the rotor is higher than the suspension accuracy of the rotor acquired in the previous week.

The first processing module 503 is configured to adjust the eddy separation weighting coefficient along the preset direction by using the first step length in the case that the determination result of the first determining module 502 is YES, and then trigger the suspension precision determining module 501.

In the case where the initial value of the vortex separation weighting coefficient is 0, the eddy separation weighting coefficient is adjusted along the preset direction by using the first step length, specifically by using the first step length to increase the eddy separation weighting coefficient; In the case where the initial value of the coefficient is 1, the first step is used to adjust the eddy separation weighting coefficient along the preset direction. Specifically, the first step length is used to reduce the eddy separation weighting coefficient. In the implementation, the first step length can be a fixed value or a variable value. Preferably, the first step is between 0.001 and 0.01.

The second processing module 504 is configured to determine, as the determination result of the first determining module 502 is negative, the eddy separation weighting coefficient used in the previous period as the optimal eddy separation weighting coefficient.

The weighting coefficient determining unit shown in FIG. 8 of the present invention, the initial value of the eddy separation weighting coefficient is 0 or 1, and the eddy separation weighting coefficient is adjusted along the preset direction by the first step length, and the eddy separation is added at each adjustment. After the weight coefficient, determine the suspension accuracy of the rotor after compensation based on the adjusted eddy separation weighting coefficient, and determine whether the suspension accuracy is higher than the suspension accuracy of the rotor in the previous week until the suspension accuracy of the rotor is lower than the previous one. The levitation accuracy in the period is determined by the eddy separation weighting coefficient used in the previous week as the optimal eddy separation weighting coefficient.

Referring to FIG. 9, FIG. 9 is a schematic structural diagram of a weighting coefficient determining unit according to the present invention. The initial value of the eddy separation weighting coefficient is a first value greater than 0 and less than 1. The weighting coefficient determining unit includes a suspension accuracy determining module 511, a first determining module 512, a third processing module 513, a fourth processing module 514, and a first value. The second determining module 515, the fifth processing module 516 and the sixth processing module 517.

among them:

The suspension accuracy determining module 511 is configured to determine a suspension accuracy of the rotor after being compensated based on the current eddy separation weighting coefficient.

The first determining module 512 is configured to determine whether the currently acquired suspension accuracy of the rotor is higher than the suspension accuracy of the rotor acquired in the previous period.

The third processing module 513 is configured to adjust the eddy separation weighting coefficient in the first direction by using the second step in the case that the determination result of the first determining module 512 is YES, and then trigger the suspension precision determining module 511.

The fourth processing module 514 is configured to determine, when the determination result of the first determining module 512 is negative, the eddy separation weighting coefficient used in the previous period as the first eddy separation weighting coefficient, and the eddy separation weighting The coefficient is adjusted to a second value, and the second value is located in the second direction of the first value, after which the suspension accuracy determination module 511 is triggered. The second direction is opposite to the first direction.

The second determining module 515 is configured to determine whether the suspension accuracy of the rotor after being compensated based on the eddy separation weighting coefficient of the second value is lower than the suspension accuracy after the compensation based on the first eddy separation weighting coefficient.

The fifth processing module 516 is configured to determine, in a case where the determination result of the second determining module 515 is YES, that the first eddy separation weighting coefficient is an optimal eddy separation weighting coefficient.

The sixth processing module 517 is configured to: when the determination result of the second determining module 515 is negative, Adjusting the eddy separation weighting coefficient in the second direction by using the third step length until the suspension accuracy of the rotor is compensated by the adjusted eddy separation weighting coefficient is lower than the suspension precision of the previous period, and will be used in the previous period The eddy separation weighting coefficient is determined as the optimal eddy separation weighting coefficient.

Adjusting the eddy separation weighting coefficient along the first direction by using the second step is specifically: increasing the eddy separation weighting coefficient by using the second step size, or reducing the eddy separation weighting coefficient by using the second step size. The second direction is opposite to the first direction. When the first direction is to increase the vortex separation weighting coefficient, the second direction is to reduce the eddy separation weighting coefficient, and when the first direction is to reduce the eddy separation weighting coefficient, The second direction is to increase the eddy separation weighting coefficient. In the implementation, the second step and the third step may be fixed values or variable values. Preferably, the second step and the third step are between 0.001 and 0.01.

In the weighting coefficient determining unit shown in FIG. 9 of the present invention, the initial value of the eddy separation weighting coefficient is between 0 and 1, and the vortex separation weighting coefficient is first adjusted in the first direction by the second step to determine the first vortex. Separating the weighting coefficient, the first eddy separation weighting coefficient is an optimal eddy separation weighting coefficient during the adjustment from the initial value in the first direction, and then adjusting the eddy separation weighting coefficient to the second direction of the initial value The second value determines that the first eddy separation weighting coefficient is the optimal eddy separation when the suspension accuracy after the rotor is compensated based on the second value is lower than the suspension accuracy compensated based on the first eddy separation weighting coefficient The weighting coefficient adjusts the eddy separation weighting coefficient in the second direction along the third step when the suspension accuracy after the rotor is compensated based on the second value is higher than the suspension accuracy compensated based on the first eddy separation weighting coefficient, Until the compensation based on the adjusted eddy separation weighting coefficient is less than the suspension accuracy of the previous week, the eddy separation used in the previous week Weights determined as optimum separation eddy weighting coefficients.

The present invention also discloses an air conditioner including a magnetic levitation compressor including a magnetic levitation bearing system, wherein the magnetic levitation bearing system includes a magnetic levitation bearing, a rotor, a power amplifier, a displacement detecting device, and the above-disclosed control device of the present invention. The air conditioner disclosed in the invention has high suspension precision and stability of the rotor in the magnetic suspension bearing system.

Finally, it should also be noted that in this paper, relational terms such as first and second are only It is only used to distinguish one entity or operation from another entity or operation, and does not necessarily require or imply any such actual relationship or order. Furthermore, the term "comprises" or "comprises" or "comprises" or any other variations thereof is intended to encompass a non-exclusive inclusion, such that a process, method, article, or device that comprises a plurality of elements includes not only those elements but also Other elements, or elements that are inherent to such a process, method, item, or device. An element that is defined by the phrase "comprising a ..." does not exclude the presence of additional equivalent elements in the process, method, item, or device that comprises the element.

The various embodiments in the present specification are described in a progressive manner, and each embodiment focuses on differences from other embodiments, and the same similar parts between the various embodiments may be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments are obvious to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but the scope of the invention is to be accorded

Claims (9)

1. A control method for a magnetic suspension bearing system, characterized in that the control method comprises:

   Obtaining a displacement signal of the rotor in the magnetic suspension bearing system;

   Determining a sinusoidal component of the displacement signal that is at the same frequency as the rotational speed;

   Compensating the displacement signal with a compensation signal, the compensation signal being a product of the sinusoidal component and an optimal eddy separation weighting coefficient;

   A control signal is generated based on the currently compensated displacement signal to control the power amplifier to adjust the excitation current flowing through the bearing coil in the magnetic suspension bearing.
2. The control method according to claim 1, wherein the initial value of the eddy separation weighting coefficient is 0 or 1, and the operation of determining the optimal eddy separation weighting coefficient comprises:

   Determining a suspension accuracy of the rotor after compensation based on a current eddy separation weighting coefficient;

   Determining whether the currently acquired suspension accuracy of the rotor is higher than the suspension accuracy of the rotor obtained in the previous week;

   If yes, adjusting the eddy separation weighting coefficient along the preset direction by using the first step length, and returning to performing the step of determining the suspension accuracy of the rotor after the compensation based on the current eddy separation weighting coefficient;

   If not, the eddy separation weighting coefficient used in the previous week is determined as the optimal eddy separation weighting coefficient.
3. The control method according to claim 2, wherein the first step length is between 0.001 and 0.01.
4. The control method according to claim 1, wherein the initial value of the eddy separation weighting coefficient is a first value greater than 0 and less than 1, and the operation of determining the optimal eddy separation weighting coefficient comprises:

   Determining a suspension accuracy of the rotor after compensation based on a current eddy separation weighting coefficient;

   Determining whether the currently acquired suspension accuracy of the rotor is higher than the suspension accuracy of the rotor obtained in the previous week;

   If yes, adjusting the eddy separation weighting coefficient in the first direction by using the second step, and returning to performing the step of determining the suspension accuracy of the rotor after the compensation based on the current eddy separation weighting coefficient;

   If not, the eddy separation weighting coefficient used in the previous week is determined as the first eddy separation weighting a coefficient, the vortex separation weighting coefficient is adjusted to a second value, the second value is located in a second direction of the first value, and the rotor is determined to be compensated based on a vortex separation weighting coefficient of the second value Whether the suspension accuracy is lower than the suspension accuracy compensated based on the first eddy separation weighting coefficient, and if so, determining that the first eddy separation weighting coefficient is the optimal eddy separation weighting coefficient; otherwise, using the third Steps adjust the vortex separation weighting coefficient along the second direction until the suspension accuracy of the rotor is lower than the suspension precision of the previous period based on the adjusted eddy separation weighting coefficient, and the previous cycle The eddy separation weighting coefficient used internally is determined as the optimal eddy separation weighting coefficient.
5. The control method according to claim 4, wherein said second step size and said third step size are between 0.001 and 0.01.
6. A control device for a magnetic suspension bearing system, comprising:

   a displacement signal acquiring unit, configured to acquire a displacement signal of the rotor in the magnetic suspension bearing system;

   a sinusoidal component determining unit, configured to determine a sinusoidal component of the displacement signal acquired by the displacement signal acquiring unit and the same frequency as the rotational speed;

   a compensation unit, configured to compensate the displacement signal by using a compensation signal, where the compensation signal is a product of the sinusoidal component and an optimal eddy separation weighting coefficient;

   a control unit, configured to generate a control signal based on the currently compensated displacement signal to control the power amplifier to adjust an excitation current flowing through the bearing coil in the magnetic suspension bearing;

   A weighting coefficient determining unit is configured to determine an optimal eddy separation weighting coefficient.
7. The control device according to claim 6, wherein the initial value of the eddy separation weighting coefficient is 0 or 1, and the weighting coefficient determining unit comprises:

   a suspension accuracy determining module, configured to determine a suspension accuracy of the rotor after being compensated based on a current eddy separation weighting coefficient;

   a first judging module, configured to determine whether the currently acquired suspension accuracy of the rotor is higher than a suspension accuracy of the rotor acquired in a previous period;

   a first processing module, configured to: when the determination result of the first determining module is YES, adjust a vortex separation weighting coefficient along a preset direction by using a first step length, and then trigger the levitation precision determining module;

   The second processing module is configured to determine, as the determination result of the first determining module is negative, the eddy separation weighting coefficient used in the previous period as the optimal eddy separation weighting coefficient.
8. The control device according to claim 6, wherein the initial value of the eddy separation weighting coefficient is a first value greater than 0 and less than 1, and the weighting coefficient determining unit comprises:

   a suspension accuracy determining module, configured to determine a suspension accuracy of the rotor after being compensated based on a current eddy separation weighting coefficient;

   a first judging module, configured to determine whether the currently acquired suspension accuracy of the rotor is higher than a suspension accuracy of the rotor acquired in a previous period;

   a third processing module, configured to: in the case that the determination result of the first determining module is YES, adjust the eddy separation weighting coefficient in the first direction by using the second step, and then trigger the suspension precision determining module;

   a fourth processing module, configured to determine, when the determination result of the first determining module is negative, a vortex separation weighting coefficient used in a previous period as a first eddy separation weighting coefficient, and to vortex separation weighting The coefficient is adjusted to a second value, the second value is located in a second direction of the first value, and then the suspension accuracy determining module is triggered;

   a second judging module, configured to determine whether the suspension accuracy of the rotor after being compensated based on the second value-based eddy separation weighting coefficient is lower than a suspension accuracy after being compensated based on the first eddy separation weighting coefficient;

   a fifth processing module, configured to determine, in a case that the determination result of the second determining module is YES, that the first eddy separation weighting coefficient is an optimal eddy separation weighting coefficient;

   a sixth processing module, configured to adjust, according to the second step, the vortex separation weighting coefficient in the second direction, if the determination result of the second determining module is negative, until the adjusted whirl After the separation weighting coefficient is compensated, the suspension accuracy of the rotor is lower than the suspension precision of the previous week, and the eddy separation weighting coefficient used in the previous week is determined as the optimal eddy separation weighting coefficient.
9. An air conditioner comprising a magnetic levitation compressor, the magnetic levitation compressor comprising a magnetic levitation bearing system, characterized in that the magnetic levitation bearing system comprises: a magnetic levitation bearing, a rotor, a power amplifier, a displacement detecting device and the like, claim 6, 7 or 8 Said control device.

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