CN116044901A - Magnetic suspension compressor and control method and device thereof - Google Patents

Magnetic suspension compressor and control method and device thereof Download PDF

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Publication number
CN116044901A
CN116044901A CN202211632055.5A CN202211632055A CN116044901A CN 116044901 A CN116044901 A CN 116044901A CN 202211632055 A CN202211632055 A CN 202211632055A CN 116044901 A CN116044901 A CN 116044901A
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China
Prior art keywords
magnetic bearing
magnetic
compressor
state
bearing rotor
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CN202211632055.5A
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Chinese (zh)
Inventor
赵科杰
闫傲
赵超一
林郁成
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Gree Electric Appliances Inc of Zhuhai
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Gree Electric Appliances Inc of Zhuhai
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Priority to CN202211632055.5A priority Critical patent/CN116044901A/en
Publication of CN116044901A publication Critical patent/CN116044901A/en
Pending legal-status Critical Current

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D25/00—Pumping installations or systems
    • F04D25/02—Units comprising pumps and their driving means
    • F04D25/06—Units comprising pumps and their driving means the pump being electrically driven
    • F04D25/0606—Units comprising pumps and their driving means the pump being electrically driven the electric motor being specially adapted for integration in the pump
    • 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
    • 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
    • F16C32/0459—Details of the magnetic circuit
    • F16C32/0468—Details of the magnetic circuit of moving parts of the magnetic circuit, e.g. of the rotor

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Magnetic Bearings And Hydrostatic Bearings (AREA)

Abstract

The invention discloses a control method and device of a magnetic suspension compressor and the magnetic suspension compressor, wherein the method comprises the following steps: after the operation of the magnetic suspension compressor is stable, determining whether the suspension state of the magnetic bearing rotor is in an unstable state according to the displacement precision of the magnetic bearing rotor; if the suspension state of the magnetic bearing rotor is in an unstable state, determining whether the suspension state of the magnetic bearing rotor is in the unstable state or not due to pressure fluctuation of an internal cavity of the magnetic suspension compressor according to the fluctuation value of the working parameter of the compressor; if the suspension state of the magnetic bearing rotor is in an unstable state and is caused by pressure fluctuation of the internal cavity of the magnetic suspension compressor, adjusting the control parameters of the magnetic bearing to obtain new control parameters of the magnetic bearing, and controlling the magnetic bearing to operate according to the new control parameters. According to the scheme, the running state of the magnetic bearing rotor is analyzed by utilizing the current of a frequency converter of the magnetic suspension compressor or the fluctuation condition of the exhaust pressure of the magnetic suspension compressor, so that the stable running of the magnetic bearing rotor is controlled.

Description

Magnetic suspension compressor and control method and device thereof
Technical Field
The invention belongs to the technical field of magnetic suspension, and particularly relates to a control method and device of a magnetic suspension compressor and the magnetic suspension compressor, in particular to a control method and device of a magnetic suspension bearing in the magnetic suspension compressor and the magnetic suspension compressor.
Background
The magnetic suspension bearing (i.e. magnetic bearing) is an intelligent bearing system (i.e. magnetic bearing control system) which uses controllable electromagnetic force to make the rotor of the magnetic suspension bearing (i.e. magnetic bearing rotor) in a non-contact suspension state. The magnetic suspension bearing has the characteristics of no abrasion, high rotating speed and low power consumption, and can realize intelligent control of the magnetic bearing rotor by combining a bearing control system, and the operation precision reaches the micron level.
In the related scheme, the magnetic bearing control system adjusts electromagnetic force of the magnetic bearing by detecting displacement precision of the magnetic bearing rotor in real time, so as to realize stable suspension of the magnetic bearing rotor. For the magnetic suspension compressor, a magnetic suspension bearing is adopted, and a magnetic suspension rotor rotating at a high speed drives an impeller to generate centrifugal force, so that low-pressure refrigerant is sucked in and high-pressure refrigerant is discharged. Because the impeller is embedded into the magnetic suspension rotor, when the pressure of the cavity of the compressor fluctuates severely, such as surge, the air flow impacts the impeller, so that the displacement precision of the magnetic bearing rotor is poor, and at the moment, the current fluctuation of the bearing coil is not obvious and is usually within 0.5A; meanwhile, the unstable state of the magnetic bearing rotor causes the change of the driving torque of the magnetic bearing rotor, and the current of the frequency converter flowing through the motor stator fluctuates greatly, which is more than 2A. Therefore, the running characteristic of the rotor cannot be fed back accurately only by means of the current of the magnetic bearing coil, and the running stability of the magnetic bearing rotor of the magnetic suspension compressor is affected.
The foregoing is provided merely for the purpose of facilitating understanding of the technical solutions of the present invention and is not intended to represent an admission that the foregoing is prior art.
Disclosure of Invention
The invention aims to provide a control method and device of a magnetic suspension compressor and the magnetic suspension compressor, so as to solve the problem that when the stable suspension of the magnetic bearing rotor is realized by detecting the displacement precision of the magnetic bearing rotor in real time and adjusting the electromagnetic force of the magnetic bearing, the stable suspension of the magnetic bearing rotor is realized by utilizing the current fluctuation condition of a frequency converter of the magnetic suspension compressor or the exhaust pressure fluctuation condition of the magnetic suspension compressor, analyzing the running state of the magnetic bearing rotor and further controlling the stable running of the magnetic bearing rotor, and further ensuring the running stability of the magnetic bearing rotor of the magnetic compressor.
The invention provides a control method of a magnetic suspension compressor, which comprises the following steps of; the control method of the magnetic suspension compressor comprises the following steps: after the magnetic suspension compressor is started, controlling the magnetic suspension compressor to run; under the condition that the running stability of the magnetic suspension compressor reaches a set stability, the displacement precision of the magnetic bearing rotor is obtained; determining whether the suspension state of the magnetic bearing rotor is in an unstable state according to the displacement precision of the magnetic bearing rotor; the unsteady state refers to a state that the suspension position of the magnetic bearing rotor deviates from a set reference position; acquiring a working parameter fluctuation value of the compressor under the condition that the suspension state of the magnetic bearing rotor is in the unstable state; according to the fluctuation value of the working parameters of the compressor, determining whether the suspension state of the magnetic bearing rotor is in the unstable state or not due to the fluctuation of the pressure of the internal cavity of the magnetic suspension compressor; under the condition that the suspension state of the magnetic bearing rotor is in the unsteady state and is caused by the pressure fluctuation of the internal cavity of the magnetic suspension compressor, adjusting the control parameters of the magnetic bearing to obtain new control parameters of the magnetic bearing; and controlling the magnetic bearing to operate according to the new control parameters of the magnetic bearing.
In some embodiments, wherein the magnetic levitation compressor further has a frequency converter; the working parameter fluctuation value of the compressor comprises the following components: the current fluctuation value of the frequency converter current of the compressor in the set detection time and/or the discharge pressure fluctuation value of the discharge pressure of the compressor in the set detection time.
In some embodiments, determining whether the levitated state of the magnetic bearing rotor is in a destabilized state according to displacement accuracy of the magnetic bearing rotor includes: determining whether the displacement precision of the magnetic bearing rotor is greater than a set displacement precision threshold; if the displacement precision of the magnetic bearing rotor is determined to be larger than the set displacement precision threshold, determining that the suspension state of the magnetic bearing rotor is in a destabilization state, and initiating a reminding message that the suspension state of the magnetic bearing rotor is in the destabilization state; if the displacement precision of the magnetic bearing rotor is determined to be smaller than or equal to the set displacement precision threshold, determining that the suspension state of the magnetic bearing rotor is in a stable state, and returning to continuously determine whether the displacement precision of the magnetic bearing rotor is larger than the set displacement precision threshold; the steady state refers to a state in which the levitation position of the magnetic bearing rotor is not deviated from a set reference position.
In some embodiments, determining whether the suspension state of the magnetic bearing rotor is in the unstable state due to pressure fluctuation of an internal cavity of the magnetic suspension compressor according to an operating parameter fluctuation value of the compressor comprises: determining whether the fluctuation value of the working parameter of the compressor is larger than a set threshold value of the fluctuation value of the working parameter; if the working parameter fluctuation value of the compressor is larger than the set working parameter fluctuation value threshold, determining that the suspension state of the magnetic bearing rotor is in the unstable state and is caused by the pressure fluctuation of the internal cavity of the magnetic suspension compressor; if the working parameter fluctuation value of the compressor is smaller than or equal to the set working parameter fluctuation value threshold, determining that the suspension state of the magnetic bearing rotor is in the unstable state and is not caused by the fluctuation of the pressure of the inner cavity of the magnetic suspension compressor, controlling the magnetic bearing to maintain the control parameter operation of the magnetic bearing, and returning to continuously determine whether the working parameter fluctuation value of the compressor is larger than the set working parameter fluctuation value threshold.
In some embodiments, further comprising: after the magnetic bearing is controlled to run according to the new control parameters of the magnetic bearing, determining whether the displacement precision of the magnetic bearing rotor is greater than a set displacement precision threshold; if the displacement precision of the magnetic bearing rotor is determined to be greater than the set displacement precision threshold, determining that the suspension state of the magnetic bearing rotor is still in an unstable state, and returning to continuously adjust the control parameters of the magnetic bearing to obtain new control parameters of the magnetic bearing; and continuing to control the magnetic bearing to run according to the new control parameters of the magnetic bearing; if the displacement precision of the magnetic bearing rotor is determined to be smaller than or equal to the set displacement precision threshold, determining that the suspension state of the magnetic bearing rotor is restored to a stable state, removing a reminding message that the suspension state of the magnetic bearing rotor is in a instable state, controlling the magnetic bearing to maintain the control parameter operation of the magnetic bearing, and returning to determine whether the suspension state of the magnetic bearing rotor is in the instable state or not according to the displacement precision of the magnetic bearing rotor again.
In accordance with the above method, another aspect of the present invention provides a control device for a magnetic levitation compressor, the magnetic levitation compressor having a magnetic bearing and a magnetic bearing rotor; the control device of the magnetic suspension compressor comprises: the control unit is configured to control the magnetic suspension compressor to run after the magnetic suspension compressor is started; an acquisition unit configured to acquire displacement accuracy of the magnetic bearing rotor in a case where a degree of stability of operation of the magnetic levitation compressor reaches a set degree of stability; the control unit is further configured to determine whether the suspension state of the magnetic bearing rotor is in a destabilization state according to the displacement precision of the magnetic bearing rotor; the unsteady state refers to a state that the suspension position of the magnetic bearing rotor deviates from a set reference position; the acquisition unit is further configured to acquire an operating parameter fluctuation value of the compressor under the condition that the suspension state of the magnetic bearing rotor is determined to be in the unstable state; the control unit is further configured to determine whether the suspension state of the magnetic bearing rotor is in the unstable state or not due to pressure fluctuation of an internal cavity of the magnetic suspension compressor according to the fluctuation value of the working parameter of the compressor; the control unit is further configured to adjust control parameters of the magnetic bearing to obtain new control parameters of the magnetic bearing under the condition that the suspension state of the magnetic bearing rotor is determined to be in the unstable state and is caused by pressure fluctuation of an internal cavity of the magnetic suspension compressor; and controlling the magnetic bearing to operate according to the new control parameters of the magnetic bearing.
In some embodiments, wherein the magnetic levitation compressor further has a frequency converter; the working parameter fluctuation value of the compressor comprises the following components: the current fluctuation value of the frequency converter current of the compressor in the set detection time and/or the discharge pressure fluctuation value of the discharge pressure of the compressor in the set detection time.
In some embodiments, the control unit determines whether the levitation state of the magnetic bearing rotor is in a unstable state according to the displacement accuracy of the magnetic bearing rotor, including: determining whether the displacement precision of the magnetic bearing rotor is greater than a set displacement precision threshold; if the displacement precision of the magnetic bearing rotor is determined to be larger than the set displacement precision threshold, determining that the suspension state of the magnetic bearing rotor is in a destabilization state, and initiating a reminding message that the suspension state of the magnetic bearing rotor is in the destabilization state; if the displacement precision of the magnetic bearing rotor is determined to be smaller than or equal to the set displacement precision threshold, determining that the suspension state of the magnetic bearing rotor is in a stable state, and returning to continuously determine whether the displacement precision of the magnetic bearing rotor is larger than the set displacement precision threshold; the steady state refers to a state in which the levitation position of the magnetic bearing rotor is not deviated from a set reference position.
In some embodiments, the control unit determines, according to an operating parameter fluctuation value of the compressor, whether a suspension state of the magnetic bearing rotor is in the unstable state or not due to pressure fluctuation of an internal cavity of the magnetic suspension compressor, including: determining whether the fluctuation value of the working parameter of the compressor is larger than a set threshold value of the fluctuation value of the working parameter; if the working parameter fluctuation value of the compressor is larger than the set working parameter fluctuation value threshold, determining that the suspension state of the magnetic bearing rotor is in the unstable state and is caused by the pressure fluctuation of the internal cavity of the magnetic suspension compressor; if the working parameter fluctuation value of the compressor is smaller than or equal to the set working parameter fluctuation value threshold, determining that the suspension state of the magnetic bearing rotor is in the unstable state and is not caused by the fluctuation of the pressure of the inner cavity of the magnetic suspension compressor, controlling the magnetic bearing to maintain the control parameter operation of the magnetic bearing, and returning to continuously determine whether the working parameter fluctuation value of the compressor is larger than the set working parameter fluctuation value threshold.
In some embodiments, further comprising: the control unit is further configured to determine whether the displacement precision of the magnetic bearing rotor is greater than a set displacement precision threshold value after controlling the magnetic bearing to operate according to the new control parameters of the magnetic bearing; the control unit is further configured to determine that the suspension state of the magnetic bearing rotor is still in a unsteady state if the displacement precision of the magnetic bearing rotor is determined to be greater than a set displacement precision threshold value, and return the suspension state to continuously adjust the control parameters of the magnetic bearing to obtain new control parameters of the magnetic bearing; and continuing to control the magnetic bearing to run according to the new control parameters of the magnetic bearing; and the control unit is further configured to determine that the suspension state of the magnetic bearing rotor is restored to the stable state if the displacement precision of the magnetic bearing rotor is determined to be smaller than or equal to the set displacement precision threshold value, remove the reminding message that the suspension state of the magnetic bearing rotor is in the unstable state, control the magnetic bearing to maintain the control parameter operation of the magnetic bearing, and return to determine whether the suspension state of the magnetic bearing rotor is in the unstable state or not according to the displacement precision of the magnetic bearing rotor again.
In accordance with another aspect of the present invention, there is provided a magnetic levitation compressor comprising: the control device of the magnetic suspension compressor is described above.
Therefore, according to the scheme of the invention, the current fluctuation threshold value of the frequency converter of the magnetic suspension compressor is set for the magnetic suspension compressor, and the running state of the magnetic bearing rotor is determined by detecting the current fluctuation value of the frequency converter in unit time; or, setting an exhaust pressure fluctuation threshold of the magnetic suspension compressor, and determining the running state of the magnetic bearing rotor by detecting the exhaust pressure fluctuation value of the magnetic suspension compressor in unit time; when the instability of the magnetic bearing rotor is determined according to the running state of the magnetic bearing rotor, the control parameters of the magnetic bearing are dynamically adjusted, and the self-adaptive stable control of the magnetic bearing rotor is realized, so that the running state of the magnetic bearing rotor is analyzed by utilizing the current fluctuation condition of a frequency converter of the magnetic suspension compressor or the exhaust pressure fluctuation condition of the magnetic suspension compressor, and the stable running of the magnetic bearing rotor is further controlled, so that the running stability of the magnetic bearing rotor of the magnetic suspension compressor is ensured.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
The technical scheme of the invention is further described in detail through the drawings and the embodiments.
Drawings
FIG. 1 is a schematic diagram of a magnetic bearing rotor destabilization state of a magnetic levitation compressor;
FIG. 2 is a flow chart of a control method of a magnetic levitation compressor according to an embodiment of the present invention;
FIG. 3 is a flow chart of an embodiment of the method of determining whether the levitation state of the magnetic bearing rotor is in a unstable state;
FIG. 4 is a flow chart of an embodiment of the method of the present invention for determining whether the levitation state of the magnetic bearing rotor is in the unstable state due to pressure fluctuations within the interior cavity of the magnetic levitation compressor;
FIG. 5 is a flow chart of an embodiment of the method of the present invention for dynamically adjusting control parameters of the magnetic bearing;
FIG. 6 is a schematic diagram illustrating a control apparatus of a magnetic levitation compressor according to an embodiment of the present invention;
FIG. 7 is a schematic diagram of displacement accuracy curves of a magnetic bearing rotor of a magnetic levitation compressor;
FIG. 8 is a schematic diagram of the current ripple of the frequency converter of the magnetic levitation compressor;
fig. 9 is a flow chart of a magnetic bearing control strategy for a magnetic levitation compressor.
In the embodiment of the present invention, reference numerals are as follows, in combination with the accompanying drawings:
102-an acquisition unit; 104-a control unit.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to specific embodiments of the present invention and corresponding drawings. It will be apparent that the described embodiments are only some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Fig. 1 is a schematic structural diagram of a magnetic bearing rotor of a magnetic levitation compressor in a unstable state. As shown in fig. 1, when the magnetic bearing rotor of the magnetic suspension compressor runs stably, the magnetic bearing rotor slightly fluctuates near the stable position A0, and the distance between the magnetic bearing rotor and the motor stator is the stable distance S0; when the magnetic bearing rotor is in an unstable state, the magnetic bearing rotor greatly fluctuates to a first fluctuation position A1 and a second fluctuation position A2, the distance between the magnetic bearing rotor and the motor stator is the first fluctuation distance S1 and the second fluctuation distance S2, the current of the frequency converter of the magnetic suspension compressor greatly fluctuates, and the exhaust pressure of the magnetic suspension compressor also greatly fluctuates. In the following, the implementation process of the scheme of the invention is exemplified by the fact that the current of the frequency converter of the magnetic levitation compressor can fluctuate greatly.
The magnetic suspension compressor needs to suspend the rotor at a stable central position, and the stable position A0 is a set reference central position. The first fluctuation position A1 and the second fluctuation position A2 refer to approximate positions of the magnetic bearing rotor when the current of the frequency converter greatly fluctuates after the rotor is unstable. The stabilizing distance S0, the first fluctuation distance S1, and the second fluctuation distance S2 are used to represent the relationship between the data amounts, for example: the stabilizing distance S0 is approximately 2000um, the first fluctuating distance S1 is 1000um, and the second fluctuating distance S2 is 3000um.
Considering that, referring to the example shown in fig. 1, for a magnetic levitation compressor, the magnetic bearing coil current is only used to levitate the rotor shaft, typically only a few a (amperes, current intensity units), and after the compressor starts to operate, as the magnetic bearing rotor rotates, the magnetic bearing coil current will fluctuate normally and slightly; meanwhile, even if the compressor is surging, the current fluctuation of the magnetic bearing coil is almost no more than 0.5A. Therefore, the levitation state of the magnetic bearing rotor at the moment cannot be judged only according to the current fluctuation of the magnetic bearing coil, and the stable operation of the magnetic bearing rotor cannot be controlled. The surge state of the compressor system can be accurately fed back under the current fluctuation condition of the frequency converter of the magnetic suspension compressor and the exhaust pressure fluctuation condition of the magnetic suspension compressor. Therefore, in order to solve the problem that the instability state of the magnetic bearing rotor of the magnetic suspension compressor shown in fig. 1 affects the operation stability of the magnetic bearing rotor, the invention provides a control method of the magnetic suspension compressor, in particular to a control method of the magnetic bearing in the magnetic suspension compressor, which can analyze the operation state of the magnetic bearing rotor by utilizing the current fluctuation condition of a frequency converter of the magnetic suspension compressor or the exhaust pressure fluctuation condition of the magnetic suspension compressor, thereby controlling the stable operation of the magnetic bearing rotor so as to ensure the operation stability of the magnetic bearing rotor of the magnetic suspension compressor.
According to an embodiment of the present invention, a control method of a magnetic levitation compressor is provided, as shown in fig. 2, which is a schematic flow chart of an embodiment of the method of the present invention. The magnetic suspension compressor is provided with a magnetic bearing and a magnetic bearing rotor. The control method of the magnetic suspension compressor comprises the following steps: step S110 to step S160.
At step S110, after the magnetic levitation compressor is started, the magnetic levitation compressor is controlled to operate.
In step S120, in the case where the degree of stability of the operation of the magnetic levitation compressor reaches the set degree of stability, the displacement accuracy of the magnetic bearing rotor is obtained, as the displacement accuracy X of the magnetic bearing rotor is actually detected.
At step S130, it is determined whether the levitation state of the magnetic bearing rotor is in an unstable state according to the displacement accuracy of the magnetic bearing rotor. The unstable state refers to a state in which the levitation position of the magnetic bearing rotor deviates from a set reference position.
In some embodiments, step S130 is a specific process of determining whether the levitation state of the magnetic bearing rotor is in the unstable state according to the displacement accuracy of the magnetic bearing rotor, see the following exemplary description.
An exemplary flowchart of determining whether the levitation state of the magnetic bearing rotor is in the unstable state in the method of the present invention shown in fig. 3 is further described below, which further describes a specific process of determining whether the levitation state of the magnetic bearing rotor is in the unstable state in step S130, including: step S210 to step S230.
Step S210, determining whether the displacement precision of the magnetic bearing rotor is larger than a set displacement precision threshold value. The set displacement accuracy threshold value is as set as displacement accuracy threshold value X of magnetic bearing rotor θ 。
Step S220, if the displacement precision of the magnetic bearing rotor is determined to be larger than the set displacement precision threshold, determining that the suspension state of the magnetic bearing rotor is in a destabilization state, and initiating a reminding message that the suspension state of the magnetic bearing rotor is in the destabilization state.
Step S230, if it is determined that the displacement precision of the magnetic bearing rotor is less than or equal to the set displacement precision threshold, determining that the suspension state of the magnetic bearing rotor is in a stable state, i.e. in a non-unstable state, and returning to continuously determine whether the displacement precision of the magnetic bearing rotor is greater than the set displacement precision threshold. The steady state refers to a state in which the levitation position of the magnetic bearing rotor is not deviated from a set reference position.
Specifically, fig. 9 is a flowchart of a magnetic bearing control strategy of the magnetic suspension compressor. As shown in fig. 9, a magnetic suspension bearing control strategy of a magnetic suspension compressor according to the present invention includes:
and step 1, after a unit in which the magnetic suspension compressor is positioned is started, controlling the magnetic suspension compressor to operate until the magnetic suspension compressor operates stably.
And 2, under the condition that the magnetic suspension compressor stably operates, if the magnetic suspension compressor reaches a stable operation state after operating for a set time, detecting the displacement precision of the magnetic bearing rotor in real time, and recording the displacement precision as the displacement precision X of the magnetic bearing rotor detected in real time. Specifically, the magnetic suspension bearing detects the displacement voltage value of the rotor through the displacement sensor, and the control system regards the difference value between the displacement voltage value measured in real time and the target voltage value as displacement precision.
Step 3, setting the displacement precision threshold value of the magnetic bearing rotor as X θ Judging whether the displacement precision X of the magnetic bearing rotor detected in real time is larger than a set displacement precision threshold value X of the magnetic bearing rotor θ . If yes, the magnetic bearing rotor is considered to be in an unstable state, and step 4 is executed to analyze the unstable state of the magnetic bearing rotor and adjust the control strategy of the magnetic bearing. Otherwise, the magnetic bearing rotor is considered to be in stable operation (namely stable operation), the magnetic bearing rotor is controlled to continue to be in stable operation, and the step 3 is returned to continue to judge whether the displacement precision X of the magnetic bearing rotor detected in real time is larger than the displacement precision threshold value of the magnetic bearing rotor is set as X θ 。
FIG. 7 is a graph schematically illustrating the displacement accuracy of the magnetic bearing rotor of the magnetic levitation compressor, as shown in FIG. 7, when the displacement accuracy X of the magnetic bearing rotor detected in real time is less than or equal to the set displacement accuracy threshold X of the magnetic bearing rotor θ At this time, the magnetic bearing rotor is in stable operation. When the displacement precision X of the magnetic bearing rotor detected in real time is more than the displacement precision threshold X of the magnetic bearing rotor θ When the magnetic bearing rotor is in a destabilization state, the magnetic bearing rotor is judged to alarm a unit (namely, the unit where the magnetic suspension compressor is located), and the destabilization state of the magnetic bearing rotor needs to be analyzed, and the control strategy of the magnetic bearing is adjusted.
At step S140, in the case where it is determined that the levitation state of the magnetic bearing rotor is in the unstable state, an operation parameter fluctuation value of the compressor is acquired.
The magnetic suspension compressor is further provided with a frequency converter. The working parameter fluctuation value of the compressor comprises the following components: the current fluctuation value of the frequency converter current of the compressor in the set detection time and/or the discharge pressure fluctuation value of the discharge pressure of the compressor in the set detection time.
At step S150, it is determined, according to the fluctuation value of the working parameter of the compressor, whether the suspension state of the magnetic bearing rotor is in the unstable state or not due to the fluctuation of the pressure of the internal cavity of the magnetic suspension compressor.
In some embodiments, in step S150, it is determined whether the suspension state of the magnetic bearing rotor is in the unstable state or not according to the fluctuation value of the operation parameter of the compressor, which is a specific process caused by the fluctuation of the pressure of the internal cavity of the magnetic levitation compressor, see the following exemplary description.
In the following, referring to fig. 4, a flowchart of an embodiment of determining whether the floating state of the magnetic bearing rotor is caused by the pressure fluctuation of the internal cavity of the magnetic suspension compressor in the method of the present invention is further described, where the determining in step S150 whether the floating state of the magnetic bearing rotor is caused by the pressure fluctuation of the internal cavity of the magnetic suspension compressor includes: step S310 to step S330.
Step S310, determining whether the fluctuation value of the working parameter of the compressor is larger than a set threshold value of the fluctuation value of the working parameter. The set operating parameter fluctuation value threshold is a set parameter threshold corresponding to the operating parameter fluctuation value. For example: when the fluctuation value of the working parameter is the current fluctuation value of the frequency converter, the set threshold value of the fluctuation value of the working parameter is the current standard fluctuation value delta I of the frequency converter θ . And when the working parameter fluctuation value is the exhaust pressure fluctuation value of the compressor, the set working parameter fluctuation value threshold is the set exhaust pressure standard fluctuation value of the compressor.
Step S320, if it is determined that the operating parameter fluctuation value of the compressor is greater than the set operating parameter fluctuation value threshold, it is determined that the suspension state of the magnetic bearing rotor is in the unstable state due to the pressure fluctuation of the internal cavity of the magnetic suspension compressor.
Step S330, if it is determined that the operating parameter fluctuation value of the compressor is less than or equal to the set operating parameter fluctuation value threshold, determining that the suspension state of the magnetic bearing rotor is not caused by the fluctuation of the internal cavity pressure of the magnetic suspension compressor, controlling the magnetic bearing to maintain the control parameter operation of the magnetic bearing, and returning to continuously determine whether the operating parameter fluctuation value of the compressor is greater than the set operating parameter fluctuation value threshold.
Specifically, as shown in fig. 9, the magnetic suspension bearing control strategy of the magnetic suspension compressor provided by the scheme of the invention further comprises:
and 4, analyzing the running state of the magnetic bearing rotor by detecting the current fluctuation value delta I of the frequency converter in unit time in real time.
Specifically, in step 4, the current standard fluctuation value of the frequency converter in unit time is set to be Δi θ . And detecting the current fluctuation value of the frequency converter of the compressor in unit time in real time, and recording the current fluctuation value as the current fluctuation value delta I of the frequency converter of the compressor in unit time detected in real time. Further, it is determined whether the current fluctuation value ΔI of the frequency converter of the compressor in the unit time detected in real time is greater than the current standard fluctuation value ΔI of the frequency converter in the set unit time θ : if yes, go to step 5 to adjust the control parameters of the magnetic bearing. Otherwise, the control parameters of the magnetic bearing are controlled to be unchanged, so that the magnetic bearing keeps the control parameters to operate.
FIG. 8 is a schematic diagram showing current fluctuation of a frequency converter of the magnetic levitation compressor, as shown in FIG. 8, setting the current standard fluctuation value of the frequency converter within a unit time to be DeltaI θ . When the current fluctuation value delta I of the frequency converter of the compressor in the unit time detected in real time is less than or equal to the current standard fluctuation value delta I of the frequency converter in the unit time θ And when the magnetic bearing rotor is in a unstable state, the magnetic bearing rotor is not caused by pressure fluctuation of the magnetic suspension compressor, and the control parameters of the bearing are not modified, so that the bearing rotor continues to operate and observe data. The return to the step of measuring the rotor displacement accuracy, the arrival here indicating that the rotor instability condition is not caused by compressor pressure fluctuations, and therefore to the magnetic axis The control parameters are not modified, and the rotor state is continuously observed. When the real-time detected current fluctuation value delta I of the frequency converter of the compressor in unit time is larger than the current standard fluctuation value delta I of the frequency converter in unit time θ And when the instability state of the magnetic bearing rotor is judged, the pressure of the internal cavity of the magnetic suspension compressor is greatly fluctuated, such as surge of the magnetic suspension compressor, so that the magnetic bearing rotor is disturbed, the displacement precision X of the magnetic bearing rotor detected in real time is deteriorated, and at the moment, the step 5 is executed.
In step S160, in the case that it is determined that the suspension state of the magnetic bearing rotor is in the unstable state and is caused by the pressure fluctuation of the internal cavity of the magnetic suspension compressor, the control parameter of the magnetic bearing is adjusted, so as to obtain a new control parameter of the magnetic bearing. And controlling the magnetic bearing to operate according to the new control parameters of the magnetic bearing.
According to the control method for the magnetic bearing in the magnetic suspension compressor, provided by the scheme of the invention, the running state of the magnetic bearing rotor is analyzed by utilizing the current fluctuation condition of the frequency converter of the magnetic suspension compressor or the exhaust pressure fluctuation condition of the magnetic suspension compressor, so that the stable running of the magnetic bearing rotor is controlled, and the running stability of the magnetic bearing rotor of the magnetic suspension compressor is ensured. Therefore, the problem that the magnetic bearing control system in the related scheme can realize the stable suspension of the magnetic bearing rotor by detecting the displacement accuracy of the magnetic bearing rotor in real time and adjusting the electromagnetic force of the magnetic bearing is solved, and the magnetic suspension compressor can not quickly and accurately detect the running state of the magnetic bearing rotor and can not quickly adjust the instability state of the magnetic bearing rotor.
Specifically, in the scheme of the invention, the current fluctuation value of the frequency converter in unit time is detected by setting the current fluctuation threshold value of the frequency converter, and the running state of the magnetic bearing rotor at the moment is analyzed. Or when the compressor stably operates, the operation state of the magnetic bearing rotor is judged by detecting the exhaust pressure fluctuation of the magnetic suspension compressor in unit time. Specifically, the exhaust pressure fluctuation threshold is set as well, and if the threshold is exceeded, it is determined that the rotor instability is caused by the internal pressure fluctuation of the compressor. The method is logically the same as the method for judging the current fluctuation value of the frequency converter, but is more accurate according to the current fluctuation value of the frequency converter. For example, under the condition of high-load operation of the compressor, the exhaust pressure also greatly fluctuates, but the magnetic bearing rotor is in stable operation, and the fluctuation of the current of the frequency converter more intuitively reflects the pressure change in the compressor, so that the operation state of the rotor is fed back. And then, in the unstability state of the magnetic bearing rotor, alarming is carried out to the magnetic bearing control system, bearing control parameters are dynamically adjusted, the self-immunity of the magnetic bearing control system is improved, the self-adaptive control of the magnetic bearing rotor is realized, the stable operation of the magnetic bearing rotor can be controlled, and the operation stability of the magnetic bearing rotor of the magnetic suspension compressor is ensured.
In some embodiments, in the method for controlling a magnetic levitation compressor according to the aspect of the present invention, the method further includes: and (3) circulating to dynamically adjust the control parameters of the magnetic suspension bearing.
The following is a schematic flow chart of an embodiment of the method of the present invention for dynamically adjusting the control parameters of the magnetic bearing, in conjunction with fig. 5, further illustrating a specific process for dynamically adjusting the control parameters of the magnetic bearing, which includes: step S410 to step S430.
Step S410, after the magnetic bearing is controlled to operate according to the new control parameters of the magnetic bearing, determining whether the displacement precision of the magnetic bearing rotor is greater than a set displacement precision threshold. The set displacement accuracy threshold value is as set as displacement accuracy threshold value X of magnetic bearing rotor θ 。
Step S420, if the displacement precision of the magnetic bearing rotor is determined to be greater than the set displacement precision threshold, determining that the suspension state of the magnetic bearing rotor is still in an unstable state, and returning to continuously adjust the control parameters of the magnetic bearing to obtain new control parameters of the magnetic bearing; and continuing to control the magnetic bearing to operate according to the new control parameters of the magnetic bearing.
Step S430, if it is determined that the displacement precision of the magnetic bearing rotor is less than or equal to the set displacement precision threshold, determining that the suspension state of the magnetic bearing rotor has been restored to a stable state, that is, in a non-unstable state, releasing a reminder message that the suspension state of the magnetic bearing rotor is in an unstable state, controlling the magnetic bearing to maintain the control parameters of the magnetic bearing to operate, and returning to determine whether the suspension state of the magnetic bearing rotor is in an unstable state according to the displacement precision of the magnetic bearing rotor again.
As shown in fig. 9, a magnetic suspension bearing control strategy of a magnetic suspension compressor according to the present invention further includes:
and 5, enabling the magnetic bearing control system to dynamically adjust control parameters of the magnetic bearing, and executing the step 6. The magnetic bearing control system parameters including bearing rigidity and damping are common to the magnetic bearing development industry. The dynamic adjustment means that the magnetic bearing control system can analyze the acquired real-time displacement voltage value, analyze the change trend of the displacement voltage value and adjust the rigidity damping parameter until the rotor stably runs.
Step 6, in the process of dynamically adjusting the control parameters of the magnetic bearing, detecting the displacement precision of the magnetic bearing rotor in real time to obtain the displacement precision X of the magnetic bearing rotor detected in real time, and judging whether the displacement precision X of the magnetic bearing rotor detected in real time is larger than a displacement precision threshold value X of the set magnetic bearing rotor or not θ : if yes, returning to the step 5, and continuing to enable the magnetic bearing control system to dynamically adjust the control parameters of the magnetic bearing. Otherwise, the magnetic bearing rotor is considered to be stable in suspension, and the step 2 is returned to carry out circulation control.
In this way, in the process of dynamically adjusting the control parameters of the magnetic bearing, the displacement precision of the magnetic bearing rotor is detected in real time to obtain the displacement precision X of the magnetic bearing rotor detected in real time until the optimal magnetic bearing control parameters are matched, so that the displacement precision X of the magnetic bearing rotor detected in real time is less than or equal to the displacement precision threshold X of the magnetic bearing rotor θ The rotor of the magnetic bearing is enabled to stably operate, the alarm is released, and the self-adaptive regulation function of the control parameters of the magnetic bearing is realized.
According to the scheme, the running state of the magnetic bearing rotor is analyzed by utilizing the current fluctuation condition of the frequency converter of the magnetic suspension compressor or the exhaust pressure fluctuation condition of the magnetic suspension compressor, the running state of the magnetic bearing rotor can be detected in real time, the quick response and adjustment of the magnetic bearing control system are realized, the anti-interference capability of the magnetic bearing control system is enhanced, and the reliability of the magnetic bearing control system is improved, so that the magnetic suspension compressor can run safely and stably.
By adopting the technical scheme of the embodiment, the running state of the magnetic bearing rotor is determined by setting the current fluctuation threshold value of the frequency converter of the magnetic suspension compressor aiming at the magnetic suspension compressor and detecting the current fluctuation value of the frequency converter in unit time. Or, setting the exhaust pressure fluctuation threshold of the magnetic suspension compressor, and determining the running state of the magnetic bearing rotor by detecting the exhaust pressure fluctuation value of the magnetic suspension compressor in unit time. When the instability of the magnetic bearing rotor is determined according to the running state of the magnetic bearing rotor, the control parameters of the magnetic bearing are dynamically adjusted, and the self-adaptive stable control of the magnetic bearing rotor is realized, so that the running state of the magnetic bearing rotor is analyzed by utilizing the current fluctuation condition of a frequency converter of the magnetic suspension compressor or the exhaust pressure fluctuation condition of the magnetic suspension compressor, and the stable running of the magnetic bearing rotor is further controlled, so that the running stability of the magnetic bearing rotor of the magnetic suspension compressor is ensured.
According to an embodiment of the present invention, there is also provided a control apparatus of a magnetic levitation compressor corresponding to the control method of the magnetic levitation compressor. Referring to fig. 6, a schematic diagram of an embodiment of the apparatus of the present invention is shown. The magnetic suspension compressor is provided with a magnetic bearing and a magnetic bearing rotor. The control device of the magnetic suspension compressor comprises: an acquisition unit 102 and a control unit 104.
Wherein, the control unit 104 is configured to control the operation of the magnetic suspension compressor after the magnetic suspension compressor is started. The specific function and process of the control unit 104 refer to step S110.
An acquisition unit 102 configured to acquire the displacement accuracy of the magnetic bearing rotor, X as actually detected, in the case where the degree of stability of the operation of the magnetic levitation compressor reaches a set degree of stability. The specific function and process of the acquisition unit 102 refer to step S120.
The control unit 104 is further configured to determine whether the levitation state of the magnetic bearing rotor is in a unstable state according to the displacement accuracy of the magnetic bearing rotor. The unstable state refers to a state in which the levitation position of the magnetic bearing rotor deviates from a set reference position. The specific function and processing of the control unit 104 is also referred to in step S130.
In some embodiments, the control unit 104 determines whether the levitation state of the magnetic bearing rotor is in a unstable state according to the displacement accuracy of the magnetic bearing rotor, including:
the control unit 104 is in particular further configured to determine whether the displacement accuracy of the magnetic bearing rotor is greater than a set displacement accuracy threshold. The set displacement accuracy threshold value is as set as displacement accuracy threshold value X of magnetic bearing rotor θ . The specific function and process of the control unit 104 also refer to step S210.
The control unit 104 is specifically further configured to determine that the suspension state of the magnetic bearing rotor is in a destabilized state if it is determined that the displacement precision of the magnetic bearing rotor is greater than the set displacement precision threshold, and initiate a notification message that the suspension state of the magnetic bearing rotor is in a destabilized state. The specific function and process of the control unit 104 is also referred to as step S220.
The control unit 104 is specifically further configured to determine that the suspension state of the magnetic bearing rotor is in a stable state, i.e. in an unstable state, and return to continuously determine whether the displacement precision of the magnetic bearing rotor is greater than a set displacement precision threshold if it is determined that the displacement precision of the magnetic bearing rotor is less than or equal to the set displacement precision threshold. The steady state refers to a state in which the levitation position of the magnetic bearing rotor is not deviated from a set reference position. The specific function and process of the control unit 104 is also referred to as step S230.
Specifically, fig. 9 is a flowchart of a magnetic bearing control strategy of the magnetic suspension compressor. As shown in fig. 9, a magnetic suspension bearing control strategy of a magnetic suspension compressor according to the present invention includes:
and step 1, after a unit in which the magnetic suspension compressor is positioned is started, controlling the magnetic suspension compressor to operate until the magnetic suspension compressor operates stably.
And 2, under the condition that the magnetic suspension compressor stably operates, if the magnetic suspension compressor reaches a stable operation state after operating for a set time, detecting the displacement precision of the magnetic bearing rotor in real time, and recording the displacement precision as the displacement precision X of the magnetic bearing rotor detected in real time.
Step 3, setting the displacement precision threshold value of the magnetic bearing rotor as X θ Judging whether the displacement precision X of the magnetic bearing rotor detected in real time is larger than a set displacement precision threshold value X of the magnetic bearing rotor θ . If yes, the magnetic bearing rotor is considered to be in an unstable state, and step 4 is executed to analyze the unstable state of the magnetic bearing rotor and adjust the control strategy of the magnetic bearing. Otherwise, the magnetic bearing rotor is considered to be in stable operation (namely stable operation), the magnetic bearing rotor is controlled to continue to be in stable operation, and the step 3 is returned to continue to judge whether the displacement precision X of the magnetic bearing rotor detected in real time is larger than the displacement precision threshold value of the magnetic bearing rotor is set as X θ 。
FIG. 7 is a graph schematically illustrating the displacement accuracy of the magnetic bearing rotor of the magnetic levitation compressor, as shown in FIG. 7, when the displacement accuracy X of the magnetic bearing rotor detected in real time is less than or equal to the set displacement accuracy threshold X of the magnetic bearing rotor θ At this time, the magnetic bearing rotor is in stable operation. When the displacement precision X of the magnetic bearing rotor detected in real time is more than the displacement precision threshold X of the magnetic bearing rotor θ When the magnetic bearing rotor is in a destabilization state, the magnetic bearing rotor is judged to alarm a unit (namely, the unit where the magnetic suspension compressor is located), and the destabilization state of the magnetic bearing rotor needs to be analyzed, and the control strategy of the magnetic bearing is adjusted.
The obtaining unit 102 is further configured to obtain an operating parameter fluctuation value of the compressor in a case where it is determined that the levitation state of the magnetic bearing rotor is in the unstable state. The specific function and processing of the acquisition unit 102 is also referred to in step S140.
The magnetic suspension compressor is further provided with a frequency converter. The working parameter fluctuation value of the compressor comprises the following components: the current fluctuation value of the frequency converter current of the compressor in the set detection time and/or the discharge pressure fluctuation value of the discharge pressure of the compressor in the set detection time.
The control unit 104 is further configured to determine, according to the operating parameter fluctuation value of the compressor, whether the suspension state of the magnetic bearing rotor is in the unstable state or not due to the pressure fluctuation of the internal cavity of the magnetic suspension compressor. The specific function and process of the control unit 104 also refer to step S150.
In some embodiments, the control unit 104 determines, according to the fluctuation value of the working parameter of the compressor, whether the suspension state of the magnetic bearing rotor is in the unstable state or not due to the fluctuation of the pressure of the internal cavity of the magnetic suspension compressor, including:
the control unit 104 is in particular further configured to determine whether the operating parameter fluctuation value of the compressor is greater than a set operating parameter fluctuation value threshold. The set operating parameter fluctuation value threshold is a set parameter threshold corresponding to the operating parameter fluctuation value. For example: when the fluctuation value of the working parameter is the current fluctuation value of the frequency converter, the set threshold value of the fluctuation value of the working parameter is the current standard fluctuation value delta I of the frequency converter θ . And when the working parameter fluctuation value is the exhaust pressure fluctuation value of the compressor, the set working parameter fluctuation value threshold is the set exhaust pressure standard fluctuation value of the compressor. The specific function and process of the control unit 104 also refer to step S310.
The control unit 104 is specifically further configured to determine that the suspension state of the magnetic bearing rotor is in the unstable state due to pressure fluctuation of the internal cavity of the magnetic suspension compressor if it is determined that the operating parameter fluctuation value of the compressor is greater than the set operating parameter fluctuation value threshold. The specific function and process of the control unit 104 also refer to step S320.
The control unit 104 is specifically further configured to determine that the suspension state of the magnetic bearing rotor is in the unstable state and is not caused by the pressure fluctuation of the internal cavity of the magnetic suspension compressor if it is determined that the working parameter fluctuation value of the compressor is smaller than or equal to the set working parameter fluctuation value threshold, control the magnetic bearing to maintain the control parameter operation of the magnetic bearing, and return to continuously determine whether the working parameter fluctuation value of the compressor is greater than the set working parameter fluctuation value threshold. The specific function and process of the control unit 104 also refer to step S330.
Specifically, as shown in fig. 9, the magnetic suspension bearing control strategy of the magnetic suspension compressor provided by the scheme of the invention further comprises:
and 4, analyzing the running state of the magnetic bearing rotor by detecting the current fluctuation value delta I of the frequency converter in unit time in real time.
Specifically, in step 4, the current standard fluctuation value of the frequency converter in unit time is set to be Δi θ . And detecting the current fluctuation value of the frequency converter of the compressor in unit time in real time, and recording the current fluctuation value as the current fluctuation value delta I of the frequency converter of the compressor in unit time detected in real time. Further, it is determined whether the current fluctuation value ΔI of the frequency converter of the compressor in the unit time detected in real time is greater than the current standard fluctuation value ΔI of the frequency converter in the set unit time θ : if yes, go to step 5 to adjust the control parameters of the magnetic bearing. Otherwise, the control parameters of the magnetic bearing are controlled to be unchanged, so that the magnetic bearing keeps the control parameters to operate.
FIG. 8 is a schematic diagram showing current fluctuation of a frequency converter of the magnetic levitation compressor, as shown in FIG. 8, setting the current standard fluctuation value of the frequency converter within a unit time to be DeltaI θ . When the current fluctuation value delta I of the frequency converter of the compressor in the unit time detected in real time is less than or equal to the current standard fluctuation value delta I of the frequency converter in the unit time θ And when the magnetic bearing rotor is in a unstable state, the magnetic bearing rotor is not caused by pressure fluctuation of the magnetic suspension compressor, and the control parameters of the bearing are not modified, so that the bearing rotor continues to operate and observe data. When the real-time detected current fluctuation value delta I of the frequency converter of the compressor in unit time is larger than the current standard fluctuation value delta I of the frequency converter in unit time θ When the instability state of the magnetic bearing rotor is judged, the pressure of the internal cavity of the magnetic suspension compressor greatly fluctuates, such as surge of the magnetic suspension compressor, so that the magnetic bearing rotor is disturbed, and the magnetic bearing is detected in real timeThe displacement accuracy X of the rotor becomes poor, and at this time, step 5 is performed.
The control unit 104 is further configured to adjust a control parameter of the magnetic bearing to obtain a new control parameter of the magnetic bearing when it is determined that the suspension state of the magnetic bearing rotor is in the unstable state due to pressure fluctuation of an internal cavity of the magnetic suspension compressor. And controlling the magnetic bearing to operate according to the new control parameters of the magnetic bearing. The specific function and process of the control unit 104 is also referred to as step S160.
According to the control device for the magnetic bearing in the magnetic suspension compressor, provided by the scheme of the invention, the running state of the magnetic bearing rotor is analyzed by utilizing the current fluctuation condition of the frequency converter of the magnetic suspension compressor or the exhaust pressure fluctuation condition of the magnetic suspension compressor, so that the stable running of the magnetic bearing rotor is controlled, and the running stability of the magnetic bearing rotor of the magnetic suspension compressor is ensured. Therefore, the problem that the magnetic bearing control system in the related scheme can realize the stable suspension of the magnetic bearing rotor by detecting the displacement accuracy of the magnetic bearing rotor in real time and adjusting the electromagnetic force of the magnetic bearing is solved, and the magnetic suspension compressor can not quickly and accurately detect the running state of the magnetic bearing rotor and can not quickly adjust the instability state of the magnetic bearing rotor.
Specifically, in the scheme of the invention, the current fluctuation value of the frequency converter in unit time is detected by setting the current fluctuation threshold value of the frequency converter, and the running state of the magnetic bearing rotor at the moment is analyzed. Or when the compressor stably operates, the operation state of the magnetic bearing rotor is judged by detecting the exhaust pressure fluctuation of the magnetic suspension compressor in unit time. And then, in the unstability state of the magnetic bearing rotor, alarming is carried out to the magnetic bearing control system, bearing control parameters are dynamically adjusted, the self-immunity of the magnetic bearing control system is improved, the self-adaptive control of the magnetic bearing rotor is realized, the stable operation of the magnetic bearing rotor can be controlled, and the operation stability of the magnetic bearing rotor of the magnetic suspension compressor is ensured.
In some embodiments, in the control device for a magnetic levitation compressor according to the aspect of the present invention, the control device further includes: the process of dynamically adjusting the control parameters of the magnetic suspension bearing by circulation is specifically as follows:
the control unit 104 is further configured to determine whether the displacement accuracy of the magnetic bearing rotor is greater than a set displacement accuracy threshold after controlling the magnetic bearing to operate with new control parameters of the magnetic bearing. The set displacement accuracy threshold value is as set as displacement accuracy threshold value X of magnetic bearing rotor θ . The specific function and process of the control unit 104 also refer to step S410.
The control unit 104 is further configured to determine that the suspension state of the magnetic bearing rotor is still in a unstable state if it is determined that the displacement precision of the magnetic bearing rotor is greater than the set displacement precision threshold, and return the suspension state to continuously adjust the control parameters of the magnetic bearing to obtain new control parameters of the magnetic bearing; and continuing to control the magnetic bearing to operate according to the new control parameters of the magnetic bearing. The specific function and process of the control unit 104 also refer to step S420.
The control unit 104 is further configured to determine that the suspension state of the magnetic bearing rotor is restored to a stable state, that is, is in a non-unstable state, and remove a notification message that the suspension state of the magnetic bearing rotor is in a unstable state, control the magnetic bearing to maintain the control parameter operation of the magnetic bearing, and return the control parameter operation, so as to determine whether the suspension state of the magnetic bearing rotor is in a unstable state again according to the displacement precision of the magnetic bearing rotor, if it is determined that the displacement precision of the magnetic bearing rotor is less than or equal to the set displacement precision threshold. The specific function and process of the control unit 104 also refer to step S430.
As shown in fig. 9, a magnetic suspension bearing control strategy of a magnetic suspension compressor according to the present invention further includes:
and 5, enabling the magnetic bearing control system to dynamically adjust control parameters of the magnetic bearing, and executing the step 6.
Step 6, in the process of dynamically adjusting the control parameters of the magnetic bearing, detecting the displacement precision of the magnetic bearing rotor in real time to obtain the displacement precision X of the magnetic bearing rotor detected in real time, and judging the magnetic shaft detected in real timeWhether the displacement precision X of the bearing rotor is larger than the displacement precision threshold value X of the set magnetic bearing rotor or not θ : if yes, returning to the step 5, and continuing to enable the magnetic bearing control system to dynamically adjust the control parameters of the magnetic bearing. Otherwise, the magnetic bearing rotor is considered to be stable in suspension, and the step 2 is returned to carry out circulation control.
In this way, in the process of dynamically adjusting the control parameters of the magnetic bearing, the displacement precision of the magnetic bearing rotor is detected in real time to obtain the displacement precision X of the magnetic bearing rotor detected in real time until the optimal magnetic bearing control parameters are matched, so that the displacement precision X of the magnetic bearing rotor detected in real time is less than or equal to the displacement precision threshold X of the magnetic bearing rotor θ The rotor of the magnetic bearing is enabled to stably operate, the alarm is released, and the self-adaptive regulation function of the control parameters of the magnetic bearing is realized.
According to the scheme, the running state of the magnetic bearing rotor is analyzed by utilizing the current fluctuation condition of the frequency converter of the magnetic suspension compressor or the exhaust pressure fluctuation condition of the magnetic suspension compressor, the running state of the magnetic bearing rotor can be detected in real time, the quick response and adjustment of the magnetic bearing control system are realized, the anti-interference capability of the magnetic bearing control system is enhanced, and the reliability of the magnetic bearing control system is improved, so that the magnetic suspension compressor can run safely and stably.
Since the processes and functions implemented by the apparatus of the present embodiment substantially correspond to the embodiments, principles and examples of the foregoing methods, the descriptions of the embodiments are not exhaustive, and reference may be made to the descriptions of the foregoing embodiments and their descriptions are omitted herein.
By adopting the technical scheme, the running state of the magnetic bearing rotor is determined by setting the current fluctuation threshold value of the frequency converter of the magnetic suspension compressor aiming at the magnetic suspension compressor and detecting the current fluctuation value of the frequency converter in unit time; or, setting an exhaust pressure fluctuation threshold of the magnetic suspension compressor, and determining the running state of the magnetic bearing rotor by detecting the exhaust pressure fluctuation value of the magnetic suspension compressor in unit time; when the instability of the magnetic bearing rotor is determined according to the running state of the magnetic bearing rotor, the control parameters of the magnetic bearing are dynamically adjusted, the self-adaptive stable control of the magnetic bearing rotor is realized, the anti-interference capability of a magnetic bearing control system can be enhanced, and the magnetic suspension compressor can run safely and stably.
According to an embodiment of the present invention, there is also provided a magnetic levitation compressor corresponding to the control device of the magnetic levitation compressor. The magnetic levitation compressor may include: the control device of the magnetic suspension compressor is described above.
Since the processing and functions implemented by the magnetic suspension compressor of the present embodiment basically correspond to the embodiments, principles and examples of the foregoing apparatus, the description of the present embodiment is not exhaustive, and reference may be made to the related descriptions of the foregoing embodiments, which are not repeated herein.
By adopting the technical scheme, the running state of the magnetic bearing rotor is determined by setting the current fluctuation threshold value of the frequency converter of the magnetic suspension compressor aiming at the magnetic suspension compressor and detecting the current fluctuation value of the frequency converter in unit time; or, setting an exhaust pressure fluctuation threshold of the magnetic suspension compressor, and determining the running state of the magnetic bearing rotor by detecting the exhaust pressure fluctuation value of the magnetic suspension compressor in unit time; when the instability of the magnetic bearing rotor is determined according to the running state of the magnetic bearing rotor, the control parameters of the magnetic bearing are dynamically adjusted, so that the self-adaptive stable control of the magnetic bearing rotor is realized, the running state of the magnetic bearing rotor can be rapidly and accurately detected, the instability state of the magnetic bearing rotor can be rapidly adjusted, the active disturbance rejection capability of a magnetic bearing control system can be improved, and the stable running of the magnetic bearing rotor is ensured.
In summary, it is readily understood by those skilled in the art that the above-described advantageous ways can be freely combined and superimposed without conflict.
The above description is only an example of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims (11)

1. The control method of the magnetic suspension compressor is characterized in that the magnetic suspension compressor is provided with a magnetic bearing and a magnetic bearing rotor; the control method of the magnetic suspension compressor comprises the following steps:
after the magnetic suspension compressor is started, controlling the magnetic suspension compressor to run;
under the condition that the running stability of the magnetic suspension compressor reaches a set stability, the displacement precision of the magnetic bearing rotor is obtained;
determining whether the suspension state of the magnetic bearing rotor is in an unstable state according to the displacement precision of the magnetic bearing rotor; the unsteady state refers to a state that the suspension position of the magnetic bearing rotor deviates from a set reference position;
Acquiring a working parameter fluctuation value of the compressor under the condition that the suspension state of the magnetic bearing rotor is in the unstable state;
according to the fluctuation value of the working parameters of the compressor, determining whether the suspension state of the magnetic bearing rotor is in the unstable state or not due to the fluctuation of the pressure of the internal cavity of the magnetic suspension compressor;
under the condition that the suspension state of the magnetic bearing rotor is in the unsteady state and is caused by the pressure fluctuation of the internal cavity of the magnetic suspension compressor, adjusting the control parameters of the magnetic bearing to obtain new control parameters of the magnetic bearing; and controlling the magnetic bearing to operate according to the new control parameters of the magnetic bearing.
2. The method for controlling a magnetic levitation compressor according to claim 1, wherein the magnetic levitation compressor further comprises a frequency converter; the working parameter fluctuation value of the compressor comprises the following components: the current fluctuation value of the frequency converter current of the compressor in the set detection time and/or the discharge pressure fluctuation value of the discharge pressure of the compressor in the set detection time.
3. A control method of a magnetic levitation compressor according to claim 1 or 2, wherein determining whether a levitation state of the magnetic bearing rotor is in a unstable state according to displacement accuracy of the magnetic bearing rotor comprises:
Determining whether the displacement precision of the magnetic bearing rotor is greater than a set displacement precision threshold;
if the displacement precision of the magnetic bearing rotor is determined to be larger than the set displacement precision threshold, determining that the suspension state of the magnetic bearing rotor is in a destabilization state, and initiating a reminding message that the suspension state of the magnetic bearing rotor is in the destabilization state;
if the displacement precision of the magnetic bearing rotor is determined to be smaller than or equal to the set displacement precision threshold, determining that the suspension state of the magnetic bearing rotor is in a stable state, and returning to continuously determine whether the displacement precision of the magnetic bearing rotor is larger than the set displacement precision threshold; the steady state refers to a state in which the levitation position of the magnetic bearing rotor is not deviated from a set reference position.
4. A control method of a magnetic levitation compressor according to any of claims 1 to 3, wherein determining whether the levitation state of the magnetic bearing rotor is caused by the fluctuation of the pressure of the internal cavity of the magnetic levitation compressor according to the fluctuation value of the operation parameter of the compressor comprises:
determining whether the fluctuation value of the working parameter of the compressor is larger than a set threshold value of the fluctuation value of the working parameter;
If the working parameter fluctuation value of the compressor is larger than the set working parameter fluctuation value threshold, determining that the suspension state of the magnetic bearing rotor is in the unstable state and is caused by the pressure fluctuation of the internal cavity of the magnetic suspension compressor;
if the working parameter fluctuation value of the compressor is smaller than or equal to the set working parameter fluctuation value threshold, determining that the suspension state of the magnetic bearing rotor is in the unstable state and is not caused by the fluctuation of the pressure of the inner cavity of the magnetic suspension compressor, controlling the magnetic bearing to maintain the control parameter operation of the magnetic bearing, and returning to continuously determine whether the working parameter fluctuation value of the compressor is larger than the set working parameter fluctuation value threshold.
5. The control method of a magnetic levitation compressor according to any one of claims 1 to 4, further comprising:
after the magnetic bearing is controlled to run according to the new control parameters of the magnetic bearing, determining whether the displacement precision of the magnetic bearing rotor is greater than a set displacement precision threshold;
if the displacement precision of the magnetic bearing rotor is determined to be greater than the set displacement precision threshold, determining that the suspension state of the magnetic bearing rotor is still in an unstable state, and returning to continuously adjust the control parameters of the magnetic bearing to obtain new control parameters of the magnetic bearing; and continuing to control the magnetic bearing to run according to the new control parameters of the magnetic bearing;
If the displacement precision of the magnetic bearing rotor is determined to be smaller than or equal to the set displacement precision threshold, determining that the suspension state of the magnetic bearing rotor is restored to a stable state, removing a reminding message that the suspension state of the magnetic bearing rotor is in a instable state, controlling the magnetic bearing to maintain the control parameter operation of the magnetic bearing, and returning to determine whether the suspension state of the magnetic bearing rotor is in the instable state or not according to the displacement precision of the magnetic bearing rotor again.
6. A control device of a magnetic suspension compressor, which is characterized in that the magnetic suspension compressor is provided with a magnetic bearing and a magnetic bearing rotor; the control device of the magnetic suspension compressor comprises:
the control unit is configured to control the magnetic suspension compressor to run after the magnetic suspension compressor is started;
an acquisition unit configured to acquire displacement accuracy of the magnetic bearing rotor in a case where a degree of stability of operation of the magnetic levitation compressor reaches a set degree of stability;
the control unit is further configured to determine whether the suspension state of the magnetic bearing rotor is in a destabilization state according to the displacement precision of the magnetic bearing rotor; the unsteady state refers to a state that the suspension position of the magnetic bearing rotor deviates from a set reference position;
The acquisition unit is further configured to acquire an operating parameter fluctuation value of the compressor under the condition that the suspension state of the magnetic bearing rotor is determined to be in the unstable state;
the control unit is further configured to determine whether the suspension state of the magnetic bearing rotor is in the unstable state or not due to pressure fluctuation of an internal cavity of the magnetic suspension compressor according to the fluctuation value of the working parameter of the compressor;
the control unit is further configured to adjust control parameters of the magnetic bearing to obtain new control parameters of the magnetic bearing under the condition that the suspension state of the magnetic bearing rotor is determined to be in the unstable state and is caused by pressure fluctuation of an internal cavity of the magnetic suspension compressor; and controlling the magnetic bearing to operate according to the new control parameters of the magnetic bearing.
7. The control device of a magnetic levitation compressor of claim 6, wherein the magnetic levitation compressor further comprises a frequency converter; the working parameter fluctuation value of the compressor comprises the following components: the current fluctuation value of the frequency converter current of the compressor in the set detection time and/or the discharge pressure fluctuation value of the discharge pressure of the compressor in the set detection time.
8. The control device of a magnetic levitation compressor according to claim 6 or 7, wherein the control unit determining whether a levitation state of the magnetic bearing rotor is in a unstable state according to displacement accuracy of the magnetic bearing rotor comprises:
determining whether the displacement precision of the magnetic bearing rotor is greater than a set displacement precision threshold;
if the displacement precision of the magnetic bearing rotor is determined to be larger than the set displacement precision threshold, determining that the suspension state of the magnetic bearing rotor is in a destabilization state, and initiating a reminding message that the suspension state of the magnetic bearing rotor is in the destabilization state;
if the displacement precision of the magnetic bearing rotor is determined to be smaller than or equal to the set displacement precision threshold, determining that the suspension state of the magnetic bearing rotor is in a stable state, and returning to continuously determine whether the displacement precision of the magnetic bearing rotor is larger than the set displacement precision threshold; the steady state refers to a state in which the levitation position of the magnetic bearing rotor is not deviated from a set reference position.
9. The control device of a magnetic levitation compressor according to any one of claims 6 to 8, wherein the control unit determining whether the levitation state of the magnetic bearing rotor is in the unstable state due to pressure fluctuation of an internal cavity of the magnetic levitation compressor according to an operation parameter fluctuation value of the compressor comprises:
Determining whether the fluctuation value of the working parameter of the compressor is larger than a set threshold value of the fluctuation value of the working parameter;
if the working parameter fluctuation value of the compressor is larger than the set working parameter fluctuation value threshold, determining that the suspension state of the magnetic bearing rotor is in the unstable state and is caused by the pressure fluctuation of the internal cavity of the magnetic suspension compressor;
if the working parameter fluctuation value of the compressor is smaller than or equal to the set working parameter fluctuation value threshold, determining that the suspension state of the magnetic bearing rotor is in the unstable state and is not caused by the fluctuation of the pressure of the inner cavity of the magnetic suspension compressor, controlling the magnetic bearing to maintain the control parameter operation of the magnetic bearing, and returning to continuously determine whether the working parameter fluctuation value of the compressor is larger than the set working parameter fluctuation value threshold.
10. A control device of a magnetic levitation compressor according to any of claims 6 to 9, further comprising:
the control unit is further configured to determine whether the displacement precision of the magnetic bearing rotor is greater than a set displacement precision threshold value after controlling the magnetic bearing to operate according to the new control parameters of the magnetic bearing;
The control unit is further configured to determine that the suspension state of the magnetic bearing rotor is still in a unsteady state if the displacement precision of the magnetic bearing rotor is determined to be greater than a set displacement precision threshold value, and return the suspension state to continuously adjust the control parameters of the magnetic bearing to obtain new control parameters of the magnetic bearing; and continuing to control the magnetic bearing to run according to the new control parameters of the magnetic bearing;
and the control unit is further configured to determine that the suspension state of the magnetic bearing rotor is restored to the stable state if the displacement precision of the magnetic bearing rotor is determined to be smaller than or equal to the set displacement precision threshold value, remove the reminding message that the suspension state of the magnetic bearing rotor is in the unstable state, control the magnetic bearing to maintain the control parameter operation of the magnetic bearing, and return to determine whether the suspension state of the magnetic bearing rotor is in the unstable state or not according to the displacement precision of the magnetic bearing rotor again.
11. A magnetic levitation compressor, comprising: a control apparatus of a magnetic levitation compressor as claimed in any one of claims 6 to 10.
CN202211632055.5A 2022-12-19 2022-12-19 Magnetic suspension compressor and control method and device thereof Pending CN116044901A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117588491A (en) * 2024-01-18 2024-02-23 瑞纳智能设备股份有限公司 Magnetic suspension bearing system, shutdown control method and device thereof and electrical equipment

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117588491A (en) * 2024-01-18 2024-02-23 瑞纳智能设备股份有限公司 Magnetic suspension bearing system, shutdown control method and device thereof and electrical equipment
CN117588491B (en) * 2024-01-18 2024-04-12 瑞纳智能设备股份有限公司 Magnetic suspension bearing system, shutdown control method and device thereof and electrical equipment

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