Rotor levitation control method and device, storage medium and magnetic levitation bearing system

Abstract

The application provides a rotor floating control method, device, storage medium and magnetic suspension bearing system. The method comprises the following steps: controlling rotor floating of the magnetic suspension bearing based on a determined center floating reference position; if the rotor floating fails, controlling rotor floating of the magnetic suspension bearing according to a first set floating direction based on the center floating reference position; wherein the first set floating direction is a set direction offset relative to the center floating reference position when the rotor floating. The scheme provided by the application can solve the problem that the current loop and displacement loop errors affect bearing control due to product structure, process and magnetic steel demagnetization.

Description

Rotor levitation control method, device, storage medium and magnetic levitation bearing system Technical Field

[0001] This invention relates to the field of control, and more particularly to a rotor lifting control method, device, storage medium, and magnetic levitation bearing system. Background Technology

[0002] In existing magnetic levitation control systems, the stable levitation of the rotor is mainly controlled by the electromagnetic force generated by energizing the bearing coils. The magnitude of the coil current is determined by the force required for the rotor to return from its current position to the reference position, which can be simply expressed as the required current. The rotor's reference position is determined by taking the median value after detecting the maximum and minimum values ​​from the displacement sensor. However, in practice, due to factors such as product manufacturing processes, structure, usage time, and temperature, the gap between the output bearing and the rotor may be too large, or the magnets in the bearing may demagnetize, resulting in insufficient bearing output and unstable rotor control. This can lead to the controller being unable to maintain stable rotor levitation. Summary of the Invention

[0003] The main objective of this invention is to overcome the deficiencies of the aforementioned related technologies and provide a rotor levitation control method, device, storage medium, and magnetic levitation bearing system for magnetic levitation bearings, so as to solve the problem in the related technologies where the rotor cannot be stably controlled when it is levitated, resulting in the controller being unable to control the rotor to levitate stably.

[0004] The present invention provides a method for controlling the buoyancy of a magnetic levitation bearing rotor, comprising: controlling the buoyancy of the magnetic levitation bearing rotor based on a determined center buoyancy reference position; if the rotor buoyancy fails, controlling the buoyancy of the magnetic levitation bearing rotor according to a first set deflection direction based on the center buoyancy reference position; wherein, the first set deflection direction is a set direction offset relative to the center buoyancy reference position when the rotor buoyancy occurs.

[0005] Optionally, the first set deflection direction is determined based on the levitation accuracy of the rotor or the bearing coil current during the levitation process; based on the central levitation reference position, controlling the rotor of the magnetic levitation bearing to levitate according to the first set deflection direction includes: offsetting the central levitation reference position by a preset unit deflection displacement according to the first set deflection direction to obtain the offset central levitation reference position; and controlling the rotor of the magnetic levitation bearing to levitate based on the obtained offset central levitation reference position.

[0006] Optionally, controlling the rotor of the magnetic levitation bearing to float according to a first set deflection direction based on the central levitation reference position further includes: when controlling the rotor of the magnetic levitation bearing to float based on the obtained offset central levitation reference position, if the rotor fails to float, then offset the offset central levitation reference position by a preset unit deflection displacement according to the first set deflection direction to obtain an offset central levitation reference position, and so on, until the rotor successfully floats or the total offset displacement reaches a preset threshold; and / or, when controlling the rotor of the magnetic levitation bearing to float based on the obtained offset central levitation reference position, if the rotor successfully floats, then the total offset displacement is used as a second set deflection displacement, and the first set deflection direction is used as the second set deflection direction, and stored in the controller of the magnetic levitation bearing.

[0007] Optionally, the first set deflection direction includes: two or more set deflection directions; based on the central buoyancy reference position, controlling the rotor of the magnetic levitation bearing to levitate according to the first set deflection direction includes: according to one of the two or more set deflection directions, offsetting the central buoyancy reference position by a preset unit deflection displacement to obtain the offset central reference position, and controlling the rotor of the magnetic levitation bearing to levitate based on the obtained offset central reference position; if the rotor fails to levitate, then according to the current deflection direction, offsetting the offset central buoyancy reference position by another preset unit deflection displacement to obtain the offset central buoyancy reference position, and so on, until the rotor successfully levitates or the total offset displacement reaches a preset threshold; if the rotor still fails to levitate until the total offset displacement reaches the preset threshold, then according to another of the two or more set deflection directions, offsetting the central buoyancy reference position by a preset unit deflection displacement to obtain the offset central reference position, and controlling the rotor of the magnetic levitation bearing to levitate based on the obtained offset central reference position, and so on, until the rotor successfully levitates.

[0008] Optionally, controlling the rotor of the magnetic levitation bearing to float according to the first set deflection direction based on the central levitation reference position further includes: when controlling the rotor of the magnetic levitation bearing to float based on the obtained offset central levitation reference position, if the rotor floats successfully, then the current offset direction is used as the second set deflection direction, and the total displacement offset according to the current offset direction is used as the second set deflection displacement, and stored in the controller of the magnetic levitation bearing.

[0009] Optionally, it further includes: a detection unit, configured to detect whether a second preset buoyancy direction and a second preset buoyancy displacement are stored in the controller of the magnetic levitation bearing before the first control unit controls the rotor of the magnetic levitation bearing to levitate; the second control unit is further configured to: if the detection unit detects that the controller stores a second preset buoyancy direction and a second preset buoyancy displacement, then control the rotor of the magnetic levitation bearing to levitate according to the second preset buoyancy direction and the second preset buoyancy displacement; if the detection unit detects that the controller does not store a second preset buoyancy direction and a second preset buoyancy displacement, then control the rotor of the magnetic levitation bearing to levitate based on a determined center buoyancy reference position.

[0010] Another aspect of the present invention provides a rotor levitation control device for a magnetic levitation bearing, comprising: a first control unit for controlling the levitation of the rotor of the magnetic levitation bearing based on a determined center levitation reference position; and a second control unit for controlling the levitation of the rotor of the magnetic levitation bearing according to a first set deflection direction based on the center levitation reference position if the rotor levitation fails; wherein the first set deflection direction is a set direction offset relative to the center levitation reference position when the rotor levits.

[0011] Optionally, the first set deflection direction is determined based on the levitation accuracy of the rotor or the bearing coil current during the levitation process; the second control unit, based on the central levitation reference position, controls the rotor of the magnetic levitation bearing to levitate according to the first set deflection direction, including: offsetting the central levitation reference position by a preset unit deflection displacement according to the first set deflection direction to obtain the offset central levitation reference position; and controlling the rotor of the magnetic levitation bearing to levitate based on the obtained offset central levitation reference position.

[0012] Optionally, the second control unit, based on the central buoyancy reference position and according to a first preset deflection direction, controls the rotor of the magnetic levitation bearing to levitate, further includes: when controlling the rotor of the magnetic levitation bearing to levitate based on the obtained offset central buoyancy reference position, if the rotor buoyancy fails, then according to the first preset deflection direction, further offset the offset central buoyancy reference position by a preset unit deflection displacement to obtain an offset central buoyancy reference position, and so on, until the rotor buoyancy is successful or the total offset displacement reaches a preset threshold; and / or, the device further includes: a first storage unit, used to, when the second control unit controls the rotor of the magnetic levitation bearing to levitate based on the obtained offset central buoyancy reference position, if the rotor buoyancy is successful, store the total offset displacement as a second preset deflection displacement and the first preset deflection direction as a second preset deflection direction in the controller of the magnetic levitation bearing.

[0013] Optionally, the first set deflection direction includes: two or more set deflection directions; the second control unit, based on the central buoyancy reference position, controls the rotor of the magnetic levitation bearing to levitate according to the first set deflection direction, including: according to one of the two or more set deflection directions, offsetting the central buoyancy reference position by a preset unit deflection displacement to obtain the offset central reference position, and controlling the rotor of the magnetic levitation bearing to levitate based on the obtained offset central reference position; if the rotor levitates but fails to levitate, then according to the current deflection direction, offsetting the offset central buoyancy reference position by another preset unit deflection displacement to obtain the offset central buoyancy reference position, and so on, until the rotor levitates successfully or the total displacement reaches a preset threshold; if the rotor still fails to levitate after the total displacement reaches the preset threshold, then according to another of the two or more set deflection directions, offsetting the central buoyancy reference position by a preset unit deflection displacement to obtain the offset central reference position, and controlling the rotor of the magnetic levitation bearing to levitate based on the obtained offset central reference position, and so on, until the rotor levitates successfully.

[0014] Optionally, the device further includes: a second storage unit, configured to, when the second control unit controls the rotor of the magnetic levitation bearing to levitate based on the obtained offset center levitation reference position, if the rotor levitation is successful, store the current offset direction as the second set deflection direction and the total displacement offset according to the current offset direction as the second set deflection displacement in the controller of the magnetic levitation bearing.

[0015] Optionally, it further includes: a detection unit, configured to detect whether a second preset buoyancy direction and a second preset buoyancy displacement are stored in the controller of the magnetic levitation bearing before the first control unit controls the rotor of the magnetic levitation bearing to levitate; if the controller is found to store a second preset buoyancy direction and a second preset buoyancy displacement, then the rotor of the magnetic levitation bearing is controlled to levitate according to the second preset buoyancy direction and the second preset buoyancy displacement; if the controller is found not to store a second preset buoyancy direction and a second preset buoyancy displacement, then the rotor of the magnetic levitation bearing is controlled to levitate based on a determined center buoyancy reference position.

[0016] In another aspect, the present invention provides a storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any of the methods described above.

[0017] In another aspect, the present invention provides a magnetic levitation bearing system, including a processor, a memory, and a computer program stored in the memory that can run on the processor, wherein the processor executes the program to implement the steps of any of the methods described above.

[0018] In another aspect, the present invention provides a magnetic levitation bearing system, including a rotor levitation control device for any of the aforementioned magnetic levitation bearings.

[0019] According to the technical solution of the present invention, by adding levitation and deflection control to the magnetic levitation control system, the problem of bearing control being affected by current loop and displacement loop errors caused by product structure, process, and magnet demagnetization can be solved. The software solution determines the required deflection direction and magnitude through data analysis or a loop mechanism; the hardware solution stores the deflection direction and displacement magnitude in EEPROM, allowing direct deflection upon the next power-on. According to the technical solution of the present invention, control errors caused by compressor structure, sensor design, and magnet demagnetization can be effectively eliminated. Attached Figure Description

[0020] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0021] Figure 1 is a schematic diagram of an embodiment of the rotor levitation control method for magnetic levitation bearings provided by the present invention;

[0022] Figure 2 shows a simplified structural diagram of the magnetic levitation bearing control system;

[0023] Figure 3 illustrates the yaw forward control;

[0024] Figure 4 shows a simplified diagram of rotor buoyancy control according to a specific embodiment of the present invention;

[0025] Figure 5 is a schematic diagram of a specific embodiment of the rotor levitation control method for magnetic levitation bearings provided by the present invention;

[0026] Figure 6 is a structural block diagram of an embodiment of the rotor levitation control device for magnetic levitation bearings provided by the present invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0028] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0029] In practice, due to product manufacturing processes, structure, and demagnetization of magnets, the gap between the output bearing and the rotor may be too large, or the magnets in the bearing may demagnetize. The center position detected by the displacement sensor is not the true center position of the rotor relative to the bearing. This may result in insufficient bearing output and unstable rotor control under certain adverse rotation conditions, as the distance between the bearing output side and the rotor force-bearing side may be relatively large in a certain direction. This may lead to the controller being unable to control the rotor to float stably.

[0030] By incorporating a bias control method into the magnetic levitation control system, the problems of displacement loop errors and insufficient bearing output affecting bearing control caused by product structure, process, and demagnetization of magnets can be solved.

[0031] This invention provides a rotor levitation control method for magnetic levitation bearings.

[0032] Figure 1 is a schematic diagram of an embodiment of the rotor levitation control method for magnetic levitation bearings provided by the present invention.

[0033] As shown in Figure 1, according to an embodiment of the present invention, the rotor levitation control method of the magnetic levitation bearing includes at least steps S110 and S120.

[0034] Step S110: Based on the determined center buoyancy reference position, control the rotor of the magnetic levitation bearing to levitate.

[0035] Specifically, before the rotor is lifted, a position detection is performed. The center lifting reference position is determined by analyzing the displacement data detected by the displacement sensor. This reference position can be determined by the rotor center position detected by the displacement sensor.

[0036] Step S120: If the rotor levitation fails, then based on the central levitation reference position, control the rotor of the magnetic levitation bearing to levitate according to the first set deflection direction. This is referred to as levitation deflection control.

[0037] The first set deflection direction is the direction in which the rotor deflects relative to the central buoyancy reference position when it is buoyed. That is, the direction in which the rotor deflects relative to the central buoyancy reference position when the rotor is controlled to buoy.

[0038] In one specific embodiment, the first set deflection direction is determined based on the levitation accuracy of the rotor or the bearing coil current during the levitation process. A preset unit deflection displacement is offset from the central levitation reference position according to the first set deflection direction to obtain the offset central levitation reference position; based on the obtained offset central levitation reference position, the rotor of the magnetic levitation bearing is controlled to levitate.

[0039] Specifically, the deflection direction is determined based on the levitation accuracy or bearing coil current during rotor levitation or before static levitation instability. The unit deflection displacement is the displacement relative to the central levitation reference position, and must be less than the gap between the bearing and the rotor; for example, it can be set to 25 reference units. A higher levitation accuracy indicates a greater displacement of the rotor from the center position in the corresponding direction. Specifically, the direction with the greatest rotor levitation accuracy can be determined as the first set deflection direction. A greater fluctuation in the bearing coil current indicates a greater displacement of the rotor from the center position in that current direction. Therefore, the direction with the greatest current fluctuation can be determined as the first set deflection direction.

[0040] When controlling the levitation of the rotor of the magnetic levitation bearing based on the obtained offset center levitation reference position, if the rotor fails to levitation, the rotor is offset by a preset unit displacement according to the first set offset direction based on the offset center levitation reference position to obtain the offset center levitation reference position. This process is repeated until the rotor successfully levits or the total offset displacement reaches a preset threshold.

[0041] For example, if the deflection direction is determined to be Fx, and the preset unit deflection displacement is 25 reference units, the center buoyancy reference position is obtained by offsetting 25 reference units according to the deflection direction Fx based on the center buoyancy reference position. The rotor is then controlled to buoy according to the offset center buoyancy reference position again. If buoyancy fails, the rotor is offset by twice the preset unit deflection displacement, i.e., (25+25) reference units, according to the deflection direction Fx based on the center buoyancy reference position to obtain the offset center buoyancy reference position. The rotor is then controlled to buoy according to the offset center buoyancy reference position again. This process is repeated until the rotor successfully buoys or the total displacement offset according to the first set deflection direction reaches a preset threshold.

[0042] Furthermore, when controlling the buoyancy of the rotor of the magnetic levitation bearing based on the obtained offset center buoyancy reference position, if the rotor buoyancy is successful, the total displacement of the offset is used as the second set offset displacement, and the first set offset direction is used as the second set offset direction, and stored in the controller of the magnetic levitation bearing.

[0043] Furthermore, before controlling the levitation of the rotor of the magnetic levitation bearing, it is detected whether the controller of the magnetic levitation bearing stores a second preset levitation direction and a second preset levitation displacement. If the controller stores the second preset levitation direction and the second preset levitation displacement, the rotor of the magnetic levitation bearing is controlled to levit according to the second preset levitation direction and the second preset levitation displacement. If the controller does not store the second preset levitation direction and the second preset levitation displacement, the rotor of the magnetic levitation bearing is controlled to levit based on the determined center levitation reference position. That is, the next time the rotor is controlled to levit, the stored second preset levitation direction and the second preset levitation displacement are directly read, and the rotor of the magnetic levitation bearing is controlled to levit based on the center levitation reference position and the second preset levitation direction and the second preset levitation displacement.

[0044] For example, if the center buoyancy reference position is obtained by offsetting the buoyancy direction Fx by a preset unit displacement of 2 times, and the rotor is successfully controlled to buoy at the offset center buoyancy reference position, the buoyancy direction Fx and the total displacement are stored in the controller EEPROM as the second set buoyancy direction and the second set buoyancy displacement. Before the unit is started up next time, the controller reads the second set buoyancy direction and the second set buoyancy displacement from the EEPROM and directly performs buoyancy control.

[0045] In another specific embodiment, the first set deflection direction includes: two or more set deflection directions.

[0046] According to one of the two or more pre-defined buoyancy directions, the rotor of the magnetic levitation bearing is offset by a preset unit buoyancy displacement based on the central buoyancy reference position to obtain the offset central reference position. Based on the obtained offset central reference position, the rotor of the magnetic levitation bearing is controlled to buoy. If the rotor fails to buoy, the rotor is offset by another preset unit buoyancy displacement based on the first pre-defined buoyancy direction based on the offset central buoyancy reference position to obtain the offset central buoyancy reference position. This process is repeated until the rotor successfully buoys or the total offset displacement reaches a preset threshold.

[0047] If the rotor fails to float even after the total displacement reaches a preset threshold, then according to another of the two or more pre-set deflection directions, a preset unit deflection displacement is applied to the center floating reference position to obtain the deflected center reference position. Based on the obtained deflected center reference position, the rotor of the magnetic levitation bearing is controlled to float, and so on, until the rotor successfully floats. Preferably, the two or more deflection directions have a preset order, for example, Fx, Fy, Rx, Ry. Fx is the horizontal direction of the rotor front section (forward bearing section); Fy is the vertical direction of the rotor front section (forward bearing section); Rx is the horizontal direction of the rotor rear section (rear bearing section); Ry is the vertical direction of the rotor rear section (rear bearing section).

[0048] In other words, if the offset center reference position obtained in one of the two or more offset directions fails to successfully lift the rotor, the other offset direction is changed, and the aforementioned steps are repeated to obtain the offset center reference position. The rotor is then controlled to lift, and this process is continued until the rotor successfully lifts. For rotor lifting control in any of the two or more offset directions, please refer to the description in the aforementioned specific embodiments; it will not be repeated here.

[0049] Furthermore, when controlling the levitation of the rotor of the magnetic levitation bearing based on the obtained offset center levitation reference position, if the rotor levitation is successful, the current offset direction is used as the second set deflection direction, and the total displacement offset according to the current offset direction is used as the second set deflection displacement, and stored in the controller of the magnetic levitation bearing.

[0050] Furthermore, before controlling the levitation of the rotor of the magnetic levitation bearing, it is detected whether the controller of the magnetic levitation bearing stores a second preset levitation direction and a second preset levitation displacement; if the controller stores a second preset levitation direction and a second preset levitation displacement, the rotor of the magnetic levitation bearing is controlled to levitation according to the second preset levitation direction and the second preset levitation displacement; if the controller does not store a second preset levitation direction and a second preset levitation displacement, the rotor of the magnetic levitation bearing is controlled to levitation based on the determined center levitation reference position.

[0051] For example, if the initial buoyancy direction is Fx and the unit buoyancy displacement is 25 units, and after three offsets in the buoyancy direction Fx, if buoyancy still fails, the buoyancy direction is changed: the second buoyancy direction is Fy, the third is Rx, the fourth is Ry, and so on, until buoyancy is successful. If buoyancy is successful in a certain state, the controller stores the buoyancy direction and displacement of that state in the controller EEPROM. Before the next unit startup, the controller first reads the buoyancy direction and displacement from the EEPROM and directly performs buoyancy control.

[0052] To clearly illustrate the technical solution of the present invention, the execution flow of the rotor levitation control method for magnetic levitation bearings provided by the present invention will be described below with a specific embodiment.

[0053] Figure 2 shows a simplified structural diagram of the magnetic levitation bearing control system. The magnetic levitation bearing control system includes: controller 1, bearings (including forward bearings, backward bearings, and axial bearings), displacement sensors, and a rotor. A five-degree-of-freedom magnetic levitation bearing control system is used as an example. Figure 3 shows the forward levitation control, i.e., the levitation control for the forward bearing. Before executing the rotor levitation control, the gap between the bearing and the rotor is 'a'. After executing the rotor levitation control, the gap between the bearing and the rotor is 'b', where b < a, resulting in more stable rotor levitation.

[0054] Figure 4 shows a simplified diagram of rotor buoyancy control according to a specific embodiment of the present invention. In the conventional method, if rotor buoyancy fails, displacement and current data prior to the failure are collected by sensors to determine the initial buoyancy direction. Control unit 1 analyzes the collected displacement data, determining the direction with the highest displacement accuracy as the buoyancy direction. Control unit 2 executes the buoyancy operation based on the determined buoyancy direction and displacement. The controller then performs another buoyancy operation. If buoyancy fails again, a rotating buoyancy mechanism is implemented until buoyancy is successful.

[0055] Figure 5 is a schematic diagram of a specific embodiment of the rotor levitation control method for magnetic levitation bearings provided by the present invention. As shown in Figure 5, firstly, the controller is powered on to prepare for the floating shaft operation, performs bearing position detection, and determines the center levitation reference position based on the detected displacement data. The system reads the floating shaft control flag bit from the EEPROM, which contains the center floating reference position of the rotor. During the initial floating, conventional floating shaft control is executed, and the controller performs the floating operation. If floating fails (either during the initial floating or due to instability and shaft drop during static levitation), a yaw control operation is performed. The initial yaw direction and displacement magnitude are determined by analyzing the accuracy and current data during the floating process or before static levitation instability. For example, the initial yaw displacement magnitude can be determined as 25 reference units. The floating operation is then performed again. If floating fails, the yaw control is performed again until floating is successful. If floating is successful, the yaw direction and displacement magnitude of this yaw control are stored in the EEPROM. Before the next rotor floating, the stored yaw direction and displacement magnitude are read from the EEPROM, and the yaw operation is executed directly.

[0056] The present invention also provides a rotor levitation control device for a magnetic levitation bearing.

[0057] Figure 6 is a structural block diagram of an embodiment of the rotor levitation control device for a magnetic levitation bearing provided by the present invention. As shown in Figure 6, the rotor levitation control device 100 includes a first control unit 110 and a second control unit 120.

[0058] The first control unit 110 is used to control the levitation of the rotor of the magnetic levitation bearing based on a determined center levitation reference position.

[0059] Specifically, before the rotor is lifted, a position detection is performed. The center lifting reference position is determined by analyzing the displacement data detected by the displacement sensor. This reference position can be determined by the rotor center position detected by the displacement sensor.

[0060] The second control unit 120 is used to control the rotor of the magnetic levitation bearing to float according to the first set deflection direction based on the center floating reference position if the rotor fails to float.

[0061] The first set deflection direction is the direction in which the rotor deflects relative to the central buoyancy reference position when it is buoyed. That is, the direction in which the rotor deflects relative to the central buoyancy reference position when the rotor is controlled to buoy.

[0062] In one specific embodiment, the first set deflection direction is determined based on the levitation accuracy of the rotor during the levitation process or the bearing coil current. The second control unit 120, based on the central levitation reference position and according to the first set deflection direction, controls the levitation of the magnetic levitation bearing rotor, which specifically includes: offsetting the central levitation reference position by a preset unit deflection displacement according to the first set deflection direction to obtain the offset central levitation reference position; and controlling the levitation of the magnetic levitation bearing rotor based on the obtained offset central levitation reference position.

[0063] Specifically, the deflection direction is determined based on the levitation accuracy or bearing coil current during rotor levitation or before static levitation instability. The unit deflection displacement is the displacement relative to the central levitation reference position, and must be less than the gap between the bearing and the rotor; for example, it can be set to 25 reference units. A higher levitation accuracy indicates a greater displacement of the rotor from the center position in the corresponding direction; specifically, the direction with the greatest levitation accuracy can be determined as the set deflection direction. A greater fluctuation in the bearing coil current indicates a greater displacement of the rotor from the center position in that current direction; therefore, the direction with the greatest current fluctuation can be determined as the first set deflection direction.

[0064] The second control unit 120, based on the central buoyancy reference position and according to the first set deflection direction, controls the rotor of the magnetic levitation bearing to levitate. It further includes: when controlling the rotor of the magnetic levitation bearing to levitate based on the obtained offset central buoyancy reference position, if the rotor buoyancy fails, then according to the first set deflection direction, it further offsets the offset central buoyancy reference position by a preset unit deflection displacement to obtain the offset central buoyancy reference position, and so on, until the rotor successfully buoys or the total offset displacement reaches a preset threshold.

[0065] For example, if the deflection direction is determined to be Fx, and the preset unit deflection displacement is 25 reference units, the center buoyancy reference position is obtained by offsetting 25 reference units according to the deflection direction Fx based on the center buoyancy reference position. The rotor is then controlled to buoy according to the offset center buoyancy reference position again. If buoyancy fails, the rotor is offset by twice the preset unit deflection displacement, i.e., (25+25) reference units, according to the deflection direction Fx based on the center buoyancy reference position to obtain the offset center buoyancy reference position. The rotor is then controlled to buoy according to the offset center buoyancy reference position again. This process is repeated until the rotor successfully buoys or the total displacement offset according to the first set deflection direction reaches a preset threshold.

[0066] Furthermore, the device 100 further includes: a first storage unit (not shown), used to store in the controller of the magnetic levitation bearing if the rotor of the magnetic levitation bearing is successfully lifted when the second control unit 120 controls the rotor of the magnetic levitation bearing to lift based on the obtained center lifting reference position after the offset, and the total displacement of the offset is used as the second set offset displacement, and the first set offset direction is used as the second set offset direction.

[0067] Furthermore, the device 100 further includes: a detection unit (not shown), configured to detect whether a second preset buoyancy direction and a second preset buoyancy displacement are stored in the controller of the magnetic levitation bearing before the first control unit 110 controls the rotor of the magnetic levitation bearing to levitate; the second control unit is further configured to: if the detection unit detects that the controller stores the second preset buoyancy direction and the second preset buoyancy displacement, then control the rotor of the magnetic levitation bearing to levitate according to the second preset buoyancy direction and the second preset buoyancy displacement; if the detection unit detects that the controller does not store the second preset buoyancy direction and the second preset buoyancy displacement, then control the rotor of the magnetic levitation bearing to levitate based on a determined center buoyancy reference position.

[0068] For example, if the center buoyancy reference position is obtained by offsetting the buoyancy direction Fx by a preset unit displacement of 2 times, and the rotor is successfully controlled to buoy at the offset center buoyancy reference position, the buoyancy direction Fx and the total displacement are stored in the controller EEPROM as the second set buoyancy direction and the second set buoyancy displacement. Before the unit is started up next time, the controller reads the second set buoyancy direction and the second set buoyancy displacement from the EEPROM and directly performs buoyancy control.

[0069] In another specific embodiment, the first set deflection direction includes: two or more set deflection directions; the second control unit 120, based on the central buoyancy reference position, controls the buoyancy of the magnetic levitation bearing rotor according to the first set deflection direction, specifically includes: according to one of the set two or more deflection directions, offsetting the central buoyancy reference position by a preset unit deflection displacement to obtain the offset central reference position, and controlling the buoyancy of the magnetic levitation bearing rotor based on the obtained offset central reference position; if the rotor fails to buoy, then according to the current deflection direction, offsetting the offset central buoyancy reference position by another preset unit deflection displacement to obtain the offset central buoyancy reference position, and so on, until the rotor successfully buoys or the total offset displacement reaches a preset threshold; if the rotor still fails to buoy until the total offset displacement reaches the preset threshold, then according to another of the set two or more deflection directions, offsetting the central buoyancy reference position by a preset unit deflection displacement to obtain the offset central reference position, and controlling the buoyancy of the magnetic levitation bearing rotor based on the obtained offset central reference position, and so on, until the rotor successfully buoys.

[0070] Preferably, the two or more deflection directions have a preset order, for example, Fx, Fy, Rx, Ry. Fx is the horizontal direction of the abscissa of the rotor front section (forward bearing section); Fy is the vertical direction of the ordinate of the rotor front section (forward bearing section); Rx is the horizontal direction of the abscissa of the rotor rear section (rear bearing section); Ry is the vertical direction of the ordinate of the rotor rear section (rear bearing section).

[0071] In other words, if the offset center reference position obtained in one of the two or more offset directions fails to successfully lift the rotor, the other offset direction is changed, and the aforementioned steps are repeated to obtain the offset center reference position. The rotor is then controlled to lift, and this process is continued until the rotor successfully lifts. For rotor lifting control in any of the two or more offset directions, please refer to the description in the aforementioned specific embodiments; it will not be repeated here.

[0072] Furthermore, the device 100 also includes a second storage unit (not shown), which, when the second control unit controls the rotor of the magnetic levitation bearing to float based on the obtained offset center levitation reference position, if the rotor floats successfully, stores the current offset direction as the second set deflection direction and the total displacement offset according to the current offset direction as the second set deflection displacement in the controller of the magnetic levitation bearing.

[0073] Furthermore, the device 100 further includes: a detection unit (not shown), used to detect whether a second preset buoyancy direction and a second preset buoyancy displacement are stored in the controller of the magnetic levitation bearing before the first control unit controls the rotor of the magnetic levitation bearing to levitate; the second control unit 120 is further used to: if the detection unit detects that the controller stores the second preset buoyancy direction and the second preset buoyancy displacement, then control the rotor of the magnetic levitation bearing to levitate according to the second preset buoyancy direction and the second preset buoyancy displacement; if the detection unit detects that the controller does not store the second preset buoyancy direction and the second preset buoyancy displacement, then control the rotor of the magnetic levitation bearing to levitate based on the determined center buoyancy reference position.

[0074] For example, if the initial buoyancy direction is Fx and the unit buoyancy displacement is 25 units, and after three offsets in the buoyancy direction Fx, if buoyancy still fails, the buoyancy direction is changed: the second buoyancy direction is Fy, the third is Rx, the fourth is Ry, and so on, until buoyancy is successful. If buoyancy is successful in a certain state, the controller stores the buoyancy direction and displacement of that state in the controller EEPROM. Before the next unit startup, the controller first reads the buoyancy direction and displacement from the EEPROM and directly performs buoyancy control.

[0075] The present invention also provides a storage medium corresponding to the rotor levitation control method of the magnetic levitation bearing, wherein a computer program is stored thereon, which, when executed by a processor, implements the steps of any of the aforementioned methods.

[0076] The present invention also provides a magnetic levitation bearing system corresponding to the rotor lifting control method of the magnetic levitation bearing, comprising a processor, a memory, and a computer program stored in the memory that can run on the processor, wherein the processor executes the program to implement the steps of any of the aforementioned methods.

[0077] The present invention also provides a magnetic levitation bearing system corresponding to the rotor levitation control device of the magnetic levitation bearing, including the rotor levitation control device of any of the aforementioned magnetic levitation bearings.

[0078] Accordingly, the solution provided by this invention, by adding levitation and deflection control to the magnetic levitation control system, can solve the problem of bearing control being affected by current loop and displacement loop errors caused by product structure, manufacturing process, and magnet demagnetization. The software solution determines the required deflection direction and magnitude through data analysis or a loop mechanism; the hardware solution stores the deflection direction and displacement magnitude in EEPROM, allowing for direct deflection upon the next power-on. According to the technical solution of this invention, control errors caused by compressor structure, sensor design, and magnet demagnetization can be effectively eliminated.

[0079] The functions described herein can be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions can be stored as one or more instructions or codes on or transmitted via a computer-readable medium. Other examples and embodiments are within the scope and spirit of this invention and the appended claims. For example, due to the nature of software, the functions described above can be implemented using software executed by a processor, hardware, firmware, hardwired, or any combination thereof. Furthermore, the functional units can be integrated into a single processing unit, or each unit can exist physically separately, or two or more units can be integrated into a single unit.

[0080] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0081] The units described as separate components may or may not be physically separate. Similarly, the components of the control device may or may not be physical units; they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0082] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to related technologies, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0083] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A rotor levitation control method for a magnetic levitation bearing, characterized in that, include: Based on a determined center buoyancy reference position, the rotor of the magnetic levitation bearing is controlled to levitate. If the rotor buoyancy fails, the rotor of the magnetic levitation bearing is controlled to levitate according to a first predetermined deflection direction based on the center buoyancy reference position. The first predetermined deflection direction is a predetermined direction offset relative to the center buoyancy reference position during rotor buoyancy. The first predetermined deflection direction includes two or more predetermined deflection directions. Controlling the rotor of the magnetic levitation bearing to levitate according to the first predetermined deflection direction based on the center buoyancy reference position includes: offsetting the center buoyancy reference position by a preset unit deflection displacement according to one of the two or more predetermined deflection directions to obtain the offset center reference position, and then... The offset center reference position is used to control the buoyancy of the magnetic levitation bearing rotor. If the rotor fails to buoy, the current deflection direction is offset by a preset unit deflection displacement from the offset center buoyancy reference position to obtain the offset center buoyancy reference position. This process is repeated until the rotor successfully buoys or the total deflection displacement reaches a preset threshold. If the rotor still fails to buoy until the total deflection displacement reaches the preset threshold, the offset center reference position is offset by a preset unit deflection displacement from the center buoyancy reference position according to another deflection direction among the two or more preset deflection directions to obtain the offset center reference position. Based on the obtained offset center reference position, the rotor of the magnetic levitation bearing is controlled to buoy. This process is repeated until the rotor successfully buoys.

2. The method according to claim 1, characterized in that, The first set deflection direction is determined based on the levitation accuracy of the rotor or the bearing coil current during the levitation process; based on the central levitation reference position, the rotor of the magnetic levitation bearing is controlled to levitate according to the first set deflection direction, including: offsetting the central levitation reference position by a preset unit deflection displacement according to the first set deflection direction to obtain the offset central levitation reference position; and controlling the rotor of the magnetic levitation bearing to levitate based on the obtained offset central levitation reference position.

3. The method according to claim 2, characterized in that, Based on the central buoyancy reference position, controlling the rotor of the magnetic levitation bearing to levitate according to the first preset deflection direction further includes: when controlling the rotor of the magnetic levitation bearing to levitate based on the obtained offset central buoyancy reference position, if the rotor buoyancy fails, then according to the first preset deflection direction, further offset the offset central buoyancy reference position by a preset unit deflection displacement to obtain the offset central buoyancy reference position, and so on, until the rotor buoyancy is successful or the total offset displacement reaches a preset threshold; and / or, when controlling the rotor of the magnetic levitation bearing to levitate based on the obtained offset central buoyancy reference position, if the rotor buoyancy is successful, then the total offset displacement is used as the second preset deflection displacement, and the first preset deflection direction is used as the second preset deflection direction, and stored in the controller of the magnetic levitation bearing.

4. The method according to claim 1, characterized in that, Based on the central buoyancy reference position, the rotor of the magnetic levitation bearing is controlled to levitate according to the first set deflection direction. The method further includes: when controlling the rotor of the magnetic levitation bearing to levitate based on the obtained offset central buoyancy reference position, if the rotor levitates successfully, the current offset direction is used as the second set deflection direction, and the total displacement offset according to the current offset direction is used as the second set deflection displacement, which is stored in the controller of the magnetic levitation bearing.

5. The method according to claim 3 or 4, characterized in that, Also includes: Before controlling the rotor of the magnetic levitation bearing to float, it is detected whether the controller of the magnetic levitation bearing stores a second set deflection direction and a second set deflection displacement. If the controller detects that a second set buoyancy direction and a second set buoyancy displacement are stored, the rotor of the magnetic levitation bearing is controlled to levitate according to the second set buoyancy direction and the second set buoyancy displacement; if the controller does not detect that a second set buoyancy direction and a second set buoyancy displacement are stored, the rotor of the magnetic levitation bearing is controlled to levitate based on the determined center buoyancy reference position.

6. A rotor levitation control device for a magnetic levitation bearing, characterized in that, include: The first control unit is used to control the levitation of the rotor of the magnetic levitation bearing based on a determined center levitation reference position; The second control unit is configured to, if the rotor fails to levitate, control the rotor of the magnetic levitation bearing to levitate according to a first preset deflection direction based on the central levitation reference position; wherein, the first preset deflection direction is a preset direction offset relative to the central levitation reference position when the rotor levitates; the first preset deflection direction includes: two or more preset deflection directions; the second control unit controls the rotor of the magnetic levitation bearing to levitate according to the first preset deflection direction based on the central levitation reference position, including: offsetting the central levitation reference position by a preset unit deflection displacement according to one of the two or more preset deflection directions to obtain the offset central reference position, and based on the obtained offset central reference position... The reference position is used to control the buoyancy of the magnetic levitation bearing rotor. If the rotor fails to buoy, the reference position is shifted by a preset unit displacement based on the current deflection direction to obtain the shifted reference position. This process is repeated until the rotor successfully buoys or the total displacement reaches a preset threshold. If the rotor still fails to buoy after the total displacement reaches the preset threshold, the reference position is shifted by a preset unit displacement based on another deflection direction from the set two or more deflection directions to obtain the shifted reference position. The rotor of the magnetic levitation bearing is then controlled to buoy based on the obtained shifted reference position. This process is repeated until the rotor successfully buoys.

7. The apparatus according to claim 6, characterized in that, The set deflection direction is determined based on the levitation accuracy of the rotor during the levitation process or the bearing coil current; the second control unit, based on the central levitation reference position, controls the rotor of the magnetic levitation bearing to levitate according to the first set deflection direction, including: offsetting the central levitation reference position by a preset unit deflection displacement according to the first set deflection direction to obtain the offset central levitation reference position; and controlling the rotor of the magnetic levitation bearing to levitate based on the obtained offset central levitation reference position.

8. A storage medium, characterized in that, It stores a computer program that, when executed by a processor, implements the steps of the method according to any one of claims 1-5.

9. A magnetic levitation bearing system, characterized in that, It includes a processor, a memory, and a computer program stored in the memory that can run on the processor, wherein the processor executes the program to implement the steps of the method of any one of claims 1-5, or includes the rotor buoyancy control device of any one of claims 6-7.

Images