Control Method, Device, Maglev System and Storage Medium of Maglev System

Abstract

The present invention discloses a control method, device, magnetic levitation system and storage medium for a magnetic levitation system. The method includes: after the magnetic levitation system is powered on, obtaining the number of turns of the bearing coil, denoted as the original number of turns of the bearing coil; controlling the coil turn number adjustable device to increase the original number of turns of the bearing coil, and using the axial suction force of the axial bearing that can be provided after the original number of turns of the bearing coil becomes larger to control the axial floating of the rotor; after the axial floating of the rotor is successful, controlling the coil turn number adjustable device to restore the current number of turns of the bearing coil to the original number of turns of the bearing coil. This solution realizes the reliable axial floating of the rotor by using the coil turn number variable device to adjust the number of turns of the internal coil of the axial bearing, so as to improve the reliability of the axial floating of the rotor.

Description

Technical Field

[0001] The present invention belongs to the technical field of magnetic levitation, and particularly relates to a control method, device, magnetic levitation system and storage medium for a magnetic levitation system. Background Art

[0002] In a magnetic levitation control system (i.e., the control system of a magnetic levitation system), the force on the rotor of the motor is controlled by electromagnetic force and magnetic force. The electromagnetic force generates magnetic force by energizing the coil in the bearing of the motor, while the magnetic force exists due to a certain amount of permanent magnets placed in the bearing of the motor. However, over time, the permanent magnets in the bearing of the motor may experience demagnetization, which directly leads to a decrease in the magnetic force of the permanent magnets, resulting in the problem that the rotor cannot levitate because the permanent magnets in the bearing cannot attract in all directions during demagnetization and floating.

[0003] The above content is only used to assist in understanding the technical solution of the present invention, and does not represent an admission that the above content is prior art. Summary of the Invention

[0004] The purpose of the present invention is to provide a control method, device, magnetic levitation system and storage medium for a magnetic levitation system, so as to solve the problem that when the permanent magnets in the bearing are demagnetized over time, the inherent magnetic force of the permanent magnets decreases, and the current in the coil of the bearing cannot be increased infinitely, resulting in insufficient suction in all directions of the bearing and the rotor cannot levitate. The effect is achieved by using a coil turn number variable device to adjust the number of turns of the internal coil of the axial bearing, realizing reliable axial levitation of the rotor, and improving the reliability of the axial levitation of the rotor.

[0005] In a control method for a magnetic levitation system provided by the present invention, the magnetic levitation system includes a magnetic levitation bearing and a rotor; inside the axial bearing of the magnetic levitation bearing, a bearing coil and a coil turn number adjustable device are provided; the coil turn number adjustable device can adjust the number of turns of the bearing coil to obtain the current number of turns of the bearing coil; the control method of the magnetic levitation system includes: after the magnetic levitation system is powered on, obtaining the number of turns of the bearing coil, denoted as the original number of turns of the bearing coil; controlling the coil turn number adjustable device to increase the original number of turns of the bearing coil, and using the axial suction of the axial bearing provided after the original number of turns of the bearing coil is increased to control the axial levitation of the rotor; after the axial levitation of the rotor is successful, controlling the coil turn number adjustable device to restore the current number of turns of the bearing coil to the original number of turns of the bearing coil.

[0006] In some embodiments, the bearing coil turn number adjustable device includes: a bearing coil and an adjustment switch; the bearing coil has a fixed connection end and n turn number adjustment taps, and the number of turns of the coil connected to each turn number adjustment tap is different, where n is a positive integer; the adjustment switch has a fixed connection end and a turn number adjustment end; wherein, the fixed connection end of the bearing coil is connected to the fixed connection end of the adjustment switch; the turn number adjustment end of the adjustment switch can be connected to any one of the n turn number adjustment taps to adjust the turn number of the bearing coil and obtain the current turn number of the bearing coil.

[0007] In some embodiments, controlling the coil turn number adjustable device to increase the original turn number of the bearing coil and using the axial suction force of the axial bearing that can be provided after the original turn number of the bearing coil is increased to control the axial floating of the rotor includes: determining whether there is a pre-stored initial turn number of the bearing coil; wherein, the initial turn number of the bearing coil is the turn number of the bearing coil when the current of the bearing coil does not exceed a preset overcurrent protection threshold and the axial floating of the rotor is successful after the last startup of the magnetic levitation system; if there is a pre-stored initial turn number of the bearing coil, then controlling the coil turn number adjustable device to make the original turn number of the bearing coil be the initial turn number of the bearing coil to obtain the current turn number of the bearing coil, and then using the axial suction force of the axial bearing that can be provided by the bearing coil at the current turn number to control the axial floating of the rotor; if there is no pre-stored initial turn number of the bearing coil, then taking the original turn number of the bearing coil as the current turn number of the bearing coil, and then using the axial suction force of the axial bearing that can be provided by the bearing coil at the current turn number to control the axial floating of the rotor.

[0008] In some embodiments, controlling the axial floating of the rotor by using the axial suction force of the axial bearing that can be provided by the bearing coil at the current number of coil turns includes: controlling the rotor to start axial floating by using the axial suction force of the axial bearing that can be provided by the bearing coil at the current number of coil turns according to a preset axial floating mode; during the process of controlling the axial floating of the rotor, obtaining the actual position of the axial bearing; determining whether the axial floating of the rotor is successful according to the actual position of the axial bearing; if the axial floating of the rotor is not successful, controlling the coil turn adjustable device to further increase the number of coil turns of the bearing coil on the basis of the current number of coil turns to obtain the new current number of coil turns of the bearing coil; controlling the axial floating of the rotor continuously by using the axial suction force of the axial bearing that can be provided by the new bearing coil at the current number of coil turns; and repeating and accumulating in this way until the axial floating of the rotor is successful when the current of the bearing coil does not exceed the preset overcurrent protection threshold.

[0009] In some embodiments, determining whether the axial floating of the rotor is successful according to the actual position of the axial bearing includes: determining the actual current of the bearing coil according to the actual position of the axial bearing; determining whether the actual position of the axial bearing reaches a preset reference position and determining whether the actual current of the bearing coil is greater than the preset overcurrent protection threshold; if it is determined that the actual position of the axial bearing has reached the preset reference position and the actual current of the bearing coil is less than or equal to the preset overcurrent protection threshold, determining that the axial floating of the rotor is successful; if it is determined that the actual position of the axial bearing does not reach the preset reference position, and / or it is determined that the actual current of the bearing coil is greater than the preset overcurrent protection threshold, determining that the axial floating of the rotor is not successful.

[0010] In some embodiments, after the axial floating of the rotor is successful, controlling the coil turn adjustable device to restore the current number of coil turns of the bearing coil to the original number of coil turns of the bearing coil includes: when the current of the bearing coil does not exceed the preset overcurrent protection threshold and the axial floating of the rotor is successful, restoring the current number of coil turns of the bearing coil or the new current number of coil turns of the bearing coil to the original number of coil turns of the bearing coil when the magnetic levitation system is powered on, and controlling the normal operation of the magnetic levitation system; and when there is a new current number of coil turns of the bearing coil, determining the new current number of coil turns of the bearing coil as the initial number of coil turns of the new bearing coil, so as to control the axial floating of the rotor according to the initial number of coil turns of the new bearing coil after the magnetic levitation system is powered on next time.

[0011] In some embodiments, the coil turn number adjustable device is controlled to increase the original coil turn number of the bearing coil, and the axial suction force of the axial bearing provided by the increased original coil turn number of the bearing coil is utilized to control the axial floating of the rotor. It further includes: after the magnetic levitation system is powered on, the coil turn number adjustable device is controlled to make the original coil turn number of the bearing coil be the maximum coil turn number of the bearing coil, so as to obtain the current coil turn number of the bearing coil; according to a preset axial floating mode, the axial suction force of the axial bearing provided by the bearing coil at the current coil turn number is utilized to control the rotor to start axial floating, so that the axial floating of the rotor is successful; when the axial floating of the rotor is successful, the current coil turn number of the bearing coil is restored to the original coil turn number of the bearing coil when the magnetic levitation system is powered on, and the magnetic levitation system is controlled to operate normally.

[0012] Matched with the above method, on the other hand, the present invention provides a control device of a magnetic levitation system. The magnetic levitation system includes a magnetic levitation bearing and a rotor; inside the axial bearing of the magnetic levitation bearing, a bearing coil and a coil turn number adjustable device are provided; the coil turn number adjustable device can adjust the number of turns of the bearing coil to obtain the current coil turn number of the bearing coil; the control device of the magnetic levitation system includes an acquisition unit configured to, after the magnetic levitation system is powered on, acquire the coil turn number of the bearing coil, denoted as the original coil turn number of the bearing coil; a control unit configured to control the coil turn number adjustable device to increase the original coil turn number of the bearing coil, and utilize the axial suction force of the axial bearing provided by the increased original coil turn number of the bearing coil to control the axial floating of the rotor; the control unit is further configured to, after the axial floating of the rotor is successful, control the coil turn number adjustable device to restore the current coil turn number of the bearing coil to the original coil turn number of the bearing coil.

[0013] In some embodiments, the bearing coil turn number adjustable device includes a bearing coil and an adjustment switch; the bearing coil has a fixed connection end and n turn number adjustment taps, and the number of coil turns connected to each turn number adjustment tap is different, where n is a positive integer; the adjustment switch has a fixed connection end and a turn number adjustment end; wherein, the fixed connection end of the bearing coil is connected to the fixed connection end of the adjustment switch; the turn number adjustment end of the adjustment switch can be connected to any one of the n turn number adjustment taps to adjust the number of turns of the bearing coil to obtain the current coil turn number of the bearing coil.

[0014] In some embodiments, the control unit controls the coil turn number adjustable device to increase the original coil turn number of the bearing coil, and uses the axial suction force of the axial bearing provided after the increase of the original coil turn number of the bearing coil to control the axial floating of the rotor, including: determining whether there is a pre-stored initial coil turn number of the bearing coil; wherein, the initial coil turn number of the bearing coil is the coil turn number of the bearing coil when the current of the bearing coil does not exceed a preset overcurrent protection threshold and the axial floating of the rotor is successful after the last startup of the magnetic levitation system; if there is a pre-stored initial coil turn number of the bearing coil, then control the coil turn number adjustable device to make the original coil turn number of the bearing coil be the initial coil turn number of the bearing coil to obtain the current coil turn number of the bearing coil, and then use the axial suction force of the axial bearing provided by the bearing coil at the current coil turn number to control the axial floating of the rotor; if there is no pre-stored initial coil turn number of the bearing coil, then use the original coil turn number of the bearing coil as the current coil turn number of the bearing coil, and then use the axial suction force of the axial bearing provided by the bearing coil at the current coil turn number to control the axial floating of the rotor.

[0015] In some embodiments, the control unit uses the axial suction force of the axial bearing provided by the bearing coil at the current coil turn number to control the axial floating of the rotor, including: according to a preset axial floating mode, using the axial suction force of the axial bearing provided by the bearing coil at the current coil turn number to control the rotor to start axial floating; during the process of controlling the axial floating of the rotor, obtaining the actual position of the axial bearing; determining whether the axial floating of the rotor is successful according to the actual position of the axial bearing; if the axial floating of the rotor is not successful, then control the coil turn number adjustable device to further increase the coil turn number of the bearing coil on the basis of the current coil turn number to obtain a new current coil turn number of the bearing coil; using the axial suction force of the axial bearing provided by the new bearing coil at the current coil turn number to continue to control the axial floating of the rotor; and repeating this process in a loop until the axial floating of the rotor is successful under the condition that the current of the bearing coil does not exceed a preset overcurrent protection threshold.

[0016] In some embodiments, the control unit determines whether the rotor axially floats successfully according to the actual position of the axial bearing, including: determining the actual current of the bearing coil according to the actual position of the axial bearing; determining whether the actual position of the axial bearing reaches a preset reference position, and determining whether the actual current of the bearing coil is greater than a preset overcurrent protection threshold; if it is determined that the actual position of the axial bearing has reached the preset reference position and the actual current of the bearing coil is less than or equal to the preset overcurrent protection threshold, it is determined that the rotor axially floats successfully; if it is determined that the actual position of the axial bearing does not reach the preset reference position, and / or it is determined that the actual current of the bearing coil is greater than the preset overcurrent protection threshold, it is determined that the rotor axially floats unsuccessfully.

[0017] In some embodiments, after the rotor axially floats successfully, the control unit controls the coil turn number adjustable device to restore the current turn number of the bearing coil to the original turn number of the bearing coil, including: when the current of the bearing coil does not exceed the preset overcurrent protection threshold and the rotor axially floats successfully, restoring the current turn number of the bearing coil or the current turn number of the new bearing coil to the original turn number of the bearing coil when the magnetic levitation system is powered on, and controlling the normal operation of the magnetic levitation system; and when there is a current turn number of the new bearing coil, determining the current turn number of the new bearing coil as the initial turn number of the new bearing coil, so as to control the axial floating of the rotor according to the initial turn number of the new bearing coil after the magnetic levitation system is powered on next time.

[0018] In some embodiments, the control unit controls the coil turn number adjustable device to increase the original turn number of the bearing coil, and uses the axial suction force of the axial bearing that can be provided after the original turn number of the bearing coil increases to control the axial floating of the rotor, further including: after the magnetic levitation system is powered on, controlling the coil turn number adjustable device to make the original turn number of the bearing coil the maximum turn number of the bearing coil to obtain the current turn number of the bearing coil; according to a preset axial floating mode, using the axial suction force of the axial bearing that can be provided when the bearing coil is at the current turn number to control the rotor to start axial floating, so that the rotor axially floats successfully; when the rotor axially floats successfully, restoring the current turn number of the bearing coil to the original turn number of the bearing coil when the magnetic levitation system is powered on, and controlling the normal operation of the magnetic levitation system.

[0019] Matched with the above device, on the other hand, the present invention provides a magnetic levitation system, including: the control device of the magnetic levitation system described above.

[0020] Corresponding to the above method, on the other hand, the present invention provides a storage medium, which includes a stored program. When the program runs, it controls the device where the storage medium is located to execute the control method of the magnetic levitation system described above.

[0021] Thus, in the solution of the present invention, by adding a device with variable number of turns of the coil on the inner coil of the axial bearing of the magnetic levitation bearing, when the rotor axially floats after the magnetic levitation system is powered on, if the initial number of turns of the inner coil of the axial bearing cannot complete the axial floating of the rotor, the device with variable number of turns of the coil increases the number of turns of the inner coil of the axial bearing in an accumulative manner until the axial floating of the rotor is successful. After the axial floating of the rotor is successful, the device with variable number of turns of the coil restores the number of turns of the inner coil of the axial bearing to the initial number of turns. Therefore, by using the device with variable number of turns of the coil to adjust the number of turns of the inner coil of the axial bearing, the reliable axial floating of the rotor is realized, so as to improve the reliability of the axial floating of the rotor.

[0022] Other features and advantages of the present invention will be described in the following specification, and, in part, will be obvious from the specification, or will be understood by implementing the present invention.

[0023] The technical solution of the present invention will be further described in detail below through the drawings and embodiments. Description of the Drawings

[0024] Figure 1 It is a schematic flow chart of an embodiment of the control method of the magnetic levitation system of the present invention;

[0025] Figure 2 It is a schematic flow chart of an embodiment of the first control process of controlling the axial floating of the rotor by using the axial suction force of the axial bearing that can be provided after the original number of turns of the bearing coil becomes larger in the method of the present invention;

[0026] Figure 3 It is a schematic flow chart of an embodiment of controlling the axial floating of the rotor by using the axial suction force of the axial bearing that can be provided at the current number of turns of the bearing coil in the method of the present invention;

[0027] Figure 4 It is a schematic flow chart of an embodiment of determining whether the axial floating of the rotor is successful according to the actual position of the axial bearing in the method of the present invention;

[0028] Figure 5 It is a schematic flow chart of an embodiment of restoring the current number of turns of the bearing coil to the original number of turns of the bearing coil after the first control process in the method of the present invention;

[0029] Figure 6Schematic diagram of a process of a second control process for controlling the axial floating of a rotor by using the axial suction force provided by the original number of turns of a bearing coil after the number of turns increases in the method of the present invention;

[0030] Figure 7 Schematic diagram of a structure of an embodiment of a control device of a magnetic levitation system of the present invention;

[0031] Figure 8 Schematic diagram of a structure of an embodiment of a magnetic levitation bearing;

[0032] Figure 9 Schematic diagram of a structure of an embodiment of a first state of adding a coil turn number variable device to an axial bearing of a magnetic levitation bearing;

[0033] Figure 10 Schematic diagram of a structure of an embodiment of a second state of adding a coil turn number variable device to an axial bearing of a magnetic levitation bearing;

[0034] Figure 11 Schematic diagram of a structure of an embodiment of a controller controlling a coil turn number variable device;

[0035] Figure 12 Flowchart of an embodiment of a method for controlling the axial floating of a magnetic levitation bearing, specifically a floating process schematic diagram taking the axial direction as an example.

[0036] Combined with the accompanying drawings, the reference numerals in the embodiments of the present invention are as follows:

[0037] 1 - Coil; 2 - Permanent magnet; 3 - Coil turn number variable device; 4 - Coil turn number adjustment end; 5 - Turn number adjustment switch; 6 - Controller. Specific implementation manner

[0038] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0039] Figure 8 Schematic diagram of a structure of an embodiment of a magnetic levitation bearing. As Figure 8 shown, in the magnetic levitation bearing, the magnetic levitation bearing can be simply divided into a forward bearing, a backward bearing and an axial bearing in the axial direction. The adsorption of the axial bearing often requires a large force. However, due to the demagnetization of the permanent magnet 2 in the axial bearing and the current limiting of the bearing coil (such as coil 1), the maximum suction force of the bearing cannot meet the axial floating.

[0040] Considering that in the case of the demagnetization of the permanent magnet in the bearing over time, the inherent magnetic force of the permanent magnet will decrease, resulting in insufficient suction force in all directions of the bearing and causing the rotor to fail to levitate. Taking the axial direction as an example, when the rotor starts to levitate axially in the magnetic levitation system, a greater force is usually required for the axial movement of the bearing. However, due to the demagnetization of the permanent magnet, the axial force of the bearing decreases, which requires an increase in the electromagnetic force of the bearing coil, that is, an increase in the current passing through the coil in the bearing. However, due to the physical characteristics of the coil in the bearing, the magnitude of the current passing through the coil in the bearing is limited, which leads to the problem that the rotor cannot levitate due to the too small axial force of the bearing. And multiple failures of the rotor to levitate will cause phenomena such as wear and shaft collision of components such as the rotor and bearing in the magnetic levitation system, seriously affecting the magnetic levitation system. Therefore, the solution of the present invention provides a control method for a magnetic levitation system, by adding a device with variable coil turns in the magnetic levitation control system, which can effectively solve the problem that the bearing cannot attract in all directions during the demagnetization and levitation of the permanent magnet in the bearing, resulting in the rotor being unable to levitate. Furthermore, it can avoid the problem that multiple failures of the rotor to levitate will cause phenomena such as wear and shaft collision of components such as the rotor and bearing in the magnetic levitation system, seriously affecting the magnetic levitation system.

[0041] According to an embodiment of the present invention, there is provided a control method for a magnetic levitation system, as Figure 1 shown in the flowchart of an embodiment of the method of the present invention. The magnetic levitation system includes: a magnetic levitation bearing and a rotor. The magnetic levitation bearing includes: a forward bearing, an axial bearing, and a backward bearing. The bearing is located between the forward bearing and the backward bearing. Inside the axial bearing of the magnetic levitation bearing, a bearing coil and a coil turn adjustable device (such as a coil turn variable device 3) are provided. The coil turn adjustable device can adjust the number of turns of the bearing coil to obtain the current number of turns of the bearing coil. Specifically, Figure 9 FIG. is a schematic structural diagram of a first state of adding a coil turn variable device to the axial bearing of the magnetic levitation bearing, Figure 10 FIG. is a schematic structural diagram of a second state of adding a coil turn variable device to the axial bearing of the magnetic levitation bearing. As Figure 9 and Figure 10 shown, the coil 1 in the axial bearing is replaced with a coil with variable number of turns (such as a coil matching the coil turn variable device 3), which greatly improves the adaptability of the axial bearing.

[0042] In some embodiments, the bearing coil turn number adjustable device includes: a bearing coil and an adjustment switch. The bearing coil is a turn number adjustable coil, and the adjustment switch is, for example, a turn number adjustment switch 5. The bearing coil has a fixed connection end and n turn number adjustment taps, and the number of turns of the coil connected to each turn number adjustment tap is different, where n is a positive integer. The adjustment switch has a fixed connection end and a turn number adjustment end. Among them, the fixed connection end of the bearing coil is connected to the fixed connection end of the adjustment switch. The turn number adjustment end of the adjustment switch can be connected to any one of the n turn number adjustment taps to adjust the turn number of the bearing coil and obtain the current turn number of the bearing coil.

[0043] Specifically, Figure 11 FIG. is a schematic structural diagram of an embodiment of a controller for controlling a coil turn number variable device. As Figure 11 shown, when the controller controls the coil turn number variable device, the turn number adjustment switch 5 is controlled by the controller, and the turn number 4 of the coil is changed through the turn number adjustment switch 5 to realize the adjustment of the turn number of the bearing coil in the axial bearing.

[0044] In the solution of the present invention, a bearing coil turn number variable device (such as the coil turn number variable device 3) is added to the magnetic levitation system. As Figure 11 can be seen, the bearing coil turn number variable device 3 is composed of two parts. The first part is a coil, and a pin is led out from each turn of the coil for connecting a toggle switch (such as the turn number adjustment switch 5). The second part is a toggle switch (such as the turn number adjustment switch 5). One end of the toggle switch is connected to the controller 6 and is controlled by the controller 6, and the other end is connected to the corresponding coil joint according to the instruction of the controller 6. The bearing coil turn number variable device is used to solve the problem that the magnetic steel is demagnetized, the axial force becomes smaller, and then the current passing through the coil in the bearing is over-protected. When the axial force of the bearing is too small and the bearing cannot be axially attracted, the number of turns of the coil in the bearing is increased. At this time, the electromagnetic force range of the coil becomes larger, the axial force of the bearing becomes larger, and the bearing can be axially attracted to realize the floating of the rotor. However, if only the number of turns of the bearing coil is increased and the number of turns is uncontrollable, then the power consumption of the coil in the bearing will increase after the bearing floats successfully, resulting in waste of energy. Therefore, after the rotor axially floats successfully, the number of turns of the coil in the bearing is changed back to the original number of turns. In this way, by adding a bearing coil turn number variable device to the magnetic levitation system, the problem that the axial floating of the rotor fails due to insufficient axial force of the bearing caused by demagnetization of the magnetic steel in the bearing is avoided, and at the same time, the power consumption of the coil in the bearing is reduced, the cost is saved, which greatly increases the reliability and adaptability of the magnetic levitation system.

[0045] For example, the internal coil of the axial bearing has a plurality of coil taps arranged in parallel. One of the coil taps located at the end of the internal coil of the axial bearing among the plurality of coil taps is the first connection end, and the remaining coil taps among the plurality of coil taps are n turns adjustment ends (n is a positive integer). For example, the internal coil of the axial bearing has a first connection end, a first turns adjustment end, a second turns adjustment end, a third turns adjustment end, and a fourth turns adjustment end. The turns adjustment switch 5 has a switch connection end and a switch adjustment end. The switch connection end of the turns adjustment switch 5 is connected to the first connection end of the internal coil of the axial bearing. The switch adjustment end of the turns adjustment switch 5 can be connected to any one of the turns adjustment ends among the first turns adjustment end, the second turns adjustment end, the third turns adjustment end, and the fourth turns adjustment end of the internal coil of the axial bearing. Among them, when the switch adjustment end of the turns adjustment switch 5 is connected to the first turns adjustment end of the internal coil of the axial bearing, the actual number of turns of the internal coil of the axial bearing is the first number of turns of the coil. When the switch adjustment end of the turns adjustment switch 5 is connected to the second turns adjustment end of the internal coil of the axial bearing, the actual number of turns of the internal coil of the axial bearing is the second number of turns of the coil, and the second number of turns of the coil is greater than the first number of turns of the coil. When the switch adjustment end of the turns adjustment switch 5 is connected to the third turns adjustment end of the internal coil of the axial bearing, the actual number of turns of the internal coil of the axial bearing is the third number of turns of the coil, and the third number of turns of the coil is greater than the second number of turns of the coil. When the switch adjustment end of the turns adjustment switch 5 is connected to the fourth turns adjustment end of the internal coil of the axial bearing, the actual number of turns of the internal coil of the axial bearing is the fourth number of turns of the coil, and the fourth number of turns of the coil is greater than the third number of turns of the coil.

[0046] As Figure 1 shown, in the solution of the present invention, the control method of the magnetic levitation system includes: step S110 to step S130.

[0047] At step S110, after the magnetic levitation system is powered on, obtain the number of turns of the bearing coil, and record it as the original number of turns of the bearing coil.

[0048] At step S120, control the turns number adjustable device to make the original number of turns of the bearing coil increase, and use the axial suction force of the axial bearing provided after the original number of turns of the bearing coil increases to control the axial floating of the rotor. Specifically, control the turns number adjustable device to make the original number of turns of the bearing coil increase to obtain the current number of turns of the bearing coil. And according to the preset axial floating mode, use the axial suction force of the axial bearing provided by the bearing coil at the current number of turns to control the axial floating of the rotor. The current number of turns of the bearing coil is greater than the original number of turns of the bearing coil.

[0049] In some embodiments, in step S120, the coil turn number adjustable device is controlled to increase the original coil turn number of the bearing coil, and the axial floating of the rotor is controlled by using the axial suction force of the axial bearing provided after the original coil turn number of the bearing coil becomes larger, including: a first control process of controlling the axial floating of the rotor by using the axial suction force of the axial bearing provided after the original coil turn number of the bearing coil becomes larger. For specific details, reference can be made to the following exemplary description.

[0050] The following combines Figure 2 FIG. is a schematic flowchart of an embodiment of the first control process of controlling the axial floating of the rotor by using the axial suction force of the axial bearing provided after the original coil turn number of the bearing coil becomes larger in the method of the present invention shown, further illustrating the specific process of the first control process of controlling the axial floating of the rotor by using the axial suction force of the axial bearing provided after the original coil turn number of the bearing coil becomes larger in step S120, including: steps S210 to S230.

[0051] Step S210, after the magnetic levitation system is powered on, determine whether there is a pre-stored initial coil turn number of the bearing coil. The initial coil turn number of the bearing coil is the coil turn number of the bearing coil when the current of the bearing coil does not exceed a preset overcurrent protection threshold and the rotor axially floats successfully after the magnetic levitation system is powered on last time.

[0052] Step S220, if there is a pre-stored initial coil turn number of the bearing coil, control the coil turn number adjustable device to make the original coil turn number of the bearing coil be the initial coil turn number of the bearing coil to obtain the current coil turn number of the bearing coil. Then, control the axial floating of the rotor by using the axial suction force of the axial bearing provided by the bearing coil at the current coil turn number.

[0053] Step S230, if there is no pre-stored initial coil turn number of the bearing coil, take the original coil turn number of the bearing coil as the current coil turn number of the bearing coil. Then, control the axial floating of the rotor by using the axial suction force of the axial bearing provided by the bearing coil at the current coil turn number.

[0054] That is to say, if there is a pre-stored initial coil turn number of the bearing coil, the pre-stored initial coil turn number of the bearing coil can be called. If there is no pre-stored initial coil turn number of the bearing coil, take the original coil turn number of the bearing coil as the current coil turn number of the bearing coil. In the case of obtaining the current coil turn number of the bearing coil, control the axial floating of the rotor by using the axial suction force of the axial bearing provided by the bearing coil at the current coil turn number.

[0055] Combined withFigure 11 In the example shown, when the controller 6 of the maglev system is powered on to control the axial floating of the rotor, if the controller 6 detects overcurrent in the bearing coil of the axial bearing, the controller 6 controls the toggle switch (such as the turn number adjustment switch 5) to change the turn number adjustment terminal 4 of the coil to increase the coil turn number, and continues to control the axial floating of the rotor until the rotor floats axially and the controller detects that there is no overcurrent in the bearing coil of the axial bearing. After the rotor floats axially successfully, the turn number data is stored in the EEPROM. When starting up and floating next time, the turn number is directly changed to this value. After floating successfully, the turn number is changed back to the initial value to avoid the increase and waste of the power consumption of the bearing coil.

[0056] In some embodiments, for the specific process of controlling the axial floating of the rotor by using the axial suction force of the axial bearing provided by the bearing coil at the current coil turn number in steps S220 and S230, refer to the following exemplary description.

[0057] The following combines Figure 3 FIG. is a schematic flowchart of an embodiment of controlling the axial floating of the rotor by using the axial suction force of the axial bearing provided by the bearing coil at the current coil turn number in the method of the present invention shown, and further illustrates the specific process of controlling the axial floating of the rotor by using the axial suction force of the axial bearing provided by the bearing coil at the current coil turn number in steps S220 and S230, including: steps S310 to S360.

[0058] Step S310, according to a preset axial floating mode, use the axial suction force of the axial bearing provided by the bearing coil at the current coil turn number to control the rotor to start axial floating.

[0059] Step S320, after controlling the rotor to start axial floating, during the process of controlling the axial floating of the rotor, obtain the actual position of the axial bearing.

[0060] Step S330, during the process of controlling the axial floating of the rotor, determine whether the axial floating of the rotor is successful according to the actual position of the axial bearing.

[0061] Step S340, if the axial floating of the rotor is not successful, control the coil turn number adjustable device to further increase the coil turn number of the bearing coil on the basis of the current coil turn number to obtain a new current coil turn number of the bearing coil, so as to increase the axial suction force of the axial bearing. The new current coil turn number of the bearing coil is greater than the current coil turn number of the bearing coil.

[0062] Step S350, continue to control the axial floating of the rotor according to the floating mode by using the axial suction force of the axial bearing provided by the new bearing coil at the current coil turn number.

[0063] Step S360, perform cyclic accumulation until the rotor floats axially successfully when the current in the bearing coil does not exceed the preset overcurrent protection threshold.

[0064] Of course, if the rotor floats axially successfully, it means that the current number of turns of the bearing coil, i.e., the initial number of turns of the bearing coil, can already meet the rotor axial floating requirement. Therefore, in this case, it is not necessary to further increase the number of turns of the bearing coil based on the current number of turns.

[0065] Refer to Figure 9 and Figure 10 the example shown. Before the rotor floats axially, the axial bearing needs to be adsorbed to the set reference position. Therefore, when the magnetic levitation system is powered on and the rotor floats axially, the magnitude of the coil current in the axial bearing is determined according to the actual position of the axial bearing detected by the sensor. During the adjustment process, if the coil current in the axial bearing is greater than the protection threshold, the number of turns of the coil in the axial bearing is adjusted to increase the axial suction force of the axial bearing. The increase in the number of turns of the coil in the axial bearing can be achieved by the method of accumulation until the current in the axial bearing does not exceed the protection threshold and the rotor floats axially successfully.

[0066] In some embodiments, the specific process of determining whether the rotor floats axially successfully according to the actual position of the axial bearing in step S330 is as follows in the following exemplary description.

[0067] The following combines Figure 4 the schematic flowchart of an embodiment of determining whether the rotor floats axially successfully according to the actual position of the axial bearing in the method of the present invention shown, and further describes the specific process of determining whether the rotor floats axially successfully according to the actual position of the axial bearing in step S330, including: step S410 to step S440.

[0068] Step S410, determine the actual current of the bearing coil according to the actual position of the axial bearing.

[0069] Step S420, determine whether the actual position of the axial bearing reaches the preset reference position, and determine whether the actual current of the bearing coil is greater than the preset overcurrent protection threshold.

[0070] Step S430, if it is determined that the actual position of the axial bearing has reached the preset reference position and the actual current of the bearing coil is less than or equal to the preset overcurrent protection threshold, then determine that the rotor floats axially successfully.

[0071] Step S440: If it is determined that the actual position of the axial bearing has not reached the preset reference position, and / or it is determined that the actual current of the bearing coil is greater than the preset overcurrent protection threshold, then it is determined that the axial floating of the rotor is unsuccessful.

[0072] Among them, floating is a process in which the rotor floats from the initial position to the reference position due to the control system; during this process, if the required force is too large at a certain moment, the current may exceed the protection threshold. After floating, if the actual position is within the error range of the preset reference position, it can be determined that the floating is successful (the current does not exceed the protection threshold).

[0073] Specifically, Figure 12 is a flowchart of an embodiment of the axial floating control method for a magnetic levitation bearing, specifically a schematic diagram of the floating process taking the axial direction as an example. A module for controlling the number of turns of the bearing coil is added to the control system program of the magnetic levitation system, and a function of storing the number of turns of the coil when floating successfully into the EEPROM module is added. As Figure 12 shown, the axial floating control method for a magnetic levitation bearing includes:

[0074] Step 1: Read the number of turns of the bearing coil in the axial bearing stored in the EEPROM module, denoted as the initial number of turns of the coil.

[0075] Step 2: During floating, the displacement sensor detects the actual position of the axial bearing and feeds it back to the control system of the magnetic levitation system. The control system of the magnetic levitation system determines the current magnitude of the bearing coil in the axial bearing according to the magnitude of the actual position of the axial bearing, and judges whether the axial floating of the rotor is successful: if so, execute Step 3, otherwise execute Step 4. Among them, judging that the axial floating is successful is based on the error between the actual position of the rotor after floating and the preset reference position being within the set interval, and there is no overcurrent phenomenon (the current exceeds the protection threshold) during the floating process. For example: if the set reference position is 2 and the acceptable error is 0.5, then the actual position of the rotor after floating can be between 2.5 - 1.5 (when the current is normal).

[0076] Step 3: After successful floating, store the number of turns of the coil at this time into the EEPROM, and directly call this number of turns of the coil when starting up and floating next time. After successful floating, through the coil turn control program, restore the number of turns of the coil to the initial value to avoid the increase in power consumption and loss of the bearing coil.

[0077] Step 4: If the axial floating cannot be completed with the initial number of turns of the bearing coil in the axial bearing, then the turn control program at this time controls the number of turns of the coil, and realizes the increase in the number of turns by means of accumulation. For example, gradually increase the number of turns of the axial bearing coil by the accumulation method until the floating is successful.

[0078] In some embodiments, in step S120, the coil turn number adjustable device is controlled to increase the original coil turn number of the bearing coil, and the axial floating of the rotor is controlled by using the axial suction force of the axial bearing provided after the original coil turn number of the bearing coil becomes larger. It further includes: a second control process of controlling the axial floating of the rotor by using the axial suction force of the axial bearing provided after the original coil turn number of the bearing coil becomes larger. For specific details, please refer to the following exemplary description.

[0079] The following combines Figure 6 FIG. is a schematic flowchart of an embodiment of the second control process of controlling the axial floating of the rotor by using the axial suction force of the axial bearing provided after the original coil turn number of the bearing coil becomes larger in the method of the present invention shown. The specific process of the second control process of controlling the axial floating of the rotor by using the axial suction force of the axial bearing provided after the original coil turn number of the bearing coil becomes larger in step S120 is further described, including: steps S610 to S630.

[0080] Step S610, after the magnetic levitation system is powered on, control the coil turn number adjustable device to make the original coil turn number of the bearing coil the maximum coil turn number of the bearing coil, and obtain the current coil turn number of the bearing coil.

[0081] Step S620, according to a preset axial floating mode, use the axial suction force of the axial bearing provided by the bearing coil at the current coil turn number to control the rotor to start axial floating until the axial floating of the rotor is successful.

[0082] Step S630, when the axial floating of the rotor is successful, restore the current coil turn number of the bearing coil to the original coil turn number of the bearing coil when the magnetic levitation system is powered on, and control the normal operation of the magnetic levitation system.

[0083] Specifically, in the solution of the present invention, the number of turns of the axial bearing coil can be pulled to the maximum value when the magnetic levitation system is powered on for the first time. After successful floating, the number of turns is changed back to the initial value, and this process is repeated every time the system is powered on.

[0084] At step S130, after the axial floating of the rotor is successful, control the coil turn number adjustable device to restore the current coil turn number of the bearing coil to the original coil turn number of the bearing coil, that is, restore to the coil turn number of the bearing coil when the magnetic levitation system is powered on. Wherein, the current coil turn number of the bearing coil is the coil turn number that can make the axial floating of the rotor successful after the original coil turn number of the bearing coil becomes larger.

[0085] A control method for a magnetic levitation system provided by the solution of the present invention. By adding a device with variable number of turns of the bearing coil in the magnetic levitation control system, after adding the device with variable number of turns of the bearing coil, when encountering the situation that during the axial levitation of the rotor, due to the too small bearing force when the permanent magnet in the bearing demagnetizes and it is impossible to complete the axial levitation of the rotor, and if the current passing through the coil in the bearing is continuously increased, it will cause the overcurrent protection, then the number of turns of the bearing coil is increased by the device with variable number of turns of the bearing coil, so that the suction range of the bearing becomes larger, the suction force of the whole bearing increases, and the axial force required for the axial levitation of the rotor can be satisfied. Thus, the problem that the rotor cannot levitate due to the inability of the bearing to attract in all directions when the permanent magnet in the bearing demagnetizes and levitates can be effectively solved. Furthermore, it can avoid the problem that the repeated failure of the rotor to levitate will cause wear, shaft collision and other phenomena of components such as the rotor and the bearing in the magnetic levitation system, which will have a serious impact on the magnetic levitation system. And after the levitation is successful, the number of turns is changed back to the initial value to avoid the increase and waste of the power consumption of the bearing coil.

[0086] In some embodiments, after the axial levitation of the rotor is successful in step S130, the specific process of controlling the coil turn number adjustable device to restore the current turn number of the bearing coil to the original turn number of the bearing coil is as follows in the following exemplary description.

[0087] The following combines Figure 5 The schematic flow chart of an embodiment of restoring the current turn number of the bearing coil to the original turn number of the bearing coil after the first control process in the method of the present invention shown below further illustrates the specific process of restoring the current turn number of the bearing coil to the original turn number of the bearing coil after the first control process in step S130, including: step S510 to step S520.

[0088] Step S510, when the current of the bearing coil does not exceed the preset overcurrent protection threshold and the axial levitation of the rotor is successful, restore the current turn number of the bearing coil or the current turn number of the new bearing coil to the original turn number of the bearing coil when the magnetic levitation system is powered on, and control the normal operation of the magnetic levitation system. And,

[0089] Step S520, when there is a current turn number of the new bearing coil, determine the current turn number of the new bearing coil as the initial turn number of the new bearing coil, so as to control the axial levitation of the rotor according to the initial turn number of the new bearing coil after the magnetic levitation system is powered on next time.

[0090] In this way, the solution of the present invention can improve the adaptability of the magnetic levitation system by adding an axial bearing coil turn number variable device, specifically adding an axial bearing coil turn number variable device to the inner coil of the axial bearing, which can change the number of turns of the inner coil of the axial bearing. Specifically, when the rotor of the magnetic levitation system starts up and axially levitates, due to various reasons such as the demagnetization of the permanent magnet in the bearing, the bearing force of the bearing during levitation is not sufficient to attract the rotor, resulting in the rotor being unable to successfully levitate. After adding the axial bearing coil turn number variable device, when the bearing force of the original number of turns of the bearing coil is insufficient, the number of turns of the bearing coil is gradually increased by the cumulative method until the rotor successfully levitates. After the rotor successfully levitates, the number of turns of the bearing coil is adjusted back to the initial value to reduce the power consumption of the bearing coil, and the number value of the number of turns of the bearing coil in the case of the rotor successfully levitating is stored in a memory (such as EEPROM). When the rotor of the magnetic levitation system starts up and axially levitates next time, this number of turns is directly used for levitation, saving the levitation process and ensuring the reliability of levitation.

[0091] Adopting the technical solution of this embodiment, by installing a coil turn number variable device on the inner coil of the axial bearing of the magnetic levitation bearing, when the rotor axially levitates after the magnetic levitation system is started up, when the initial number of turns of the inner coil of the axial bearing cannot complete the axial levitation of the rotor, the number of turns of the inner coil of the axial bearing is increased in an accumulative manner through the coil turn number variable device until the axial levitation of the rotor is successful. After the axial levitation of the rotor is successful, the number of turns of the inner coil of the axial bearing is restored to the initial number of turns through the coil turn number variable device. Thus, by using the coil turn number variable device to adjust the number of turns of the inner coil of the axial bearing, the reliable axial levitation of the rotor is realized to improve the reliability of the axial levitation of the rotor.

[0092] According to an embodiment of the present invention, there is also provided a control device for a magnetic levitation system corresponding to the control method of the magnetic levitation system. Refer to Figure 7 the structural schematic diagram of an embodiment of the device of the present invention shown. The magnetic levitation system includes a magnetic levitation bearing and a rotor. The magnetic levitation bearing includes a forward bearing, an axial bearing, and a backward bearing. The bearing is located between the forward bearing and the backward bearing. Inside the axial bearing of the magnetic levitation bearing, a bearing coil and a coil turn number adjustable device (such as the coil turn number variable device 3) are provided. The coil turn number adjustable device can adjust the number of turns of the bearing coil to adjust the number of turns of the bearing coil to obtain the current number of turns of the bearing coil. Specifically, Figure 9 is the structural schematic diagram of an embodiment of the first state of adding a coil turn number variable device to the axial bearing of the magnetic levitation bearing, Figure 10 is the structural schematic diagram of an embodiment of the second state of adding a coil turn number variable device to the axial bearing of the magnetic levitation bearing. As Figure 9 and Figure 10As shown, the coil 1 in the axial bearing is replaced with a coil with variable number of turns (such as the coil matched with the device 3 for variable number of turns of the coil), which greatly improves the adaptability of the axial bearing.

[0093] In some embodiments, the device for adjusting the number of turns of the bearing coil includes: a bearing coil and an adjustment switch. The bearing coil is a coil with adjustable number of turns, and the adjustment switch is such as the turn number adjustment switch 5. The bearing coil has a fixed connection end and n turn number adjustment taps, and the number of turns of the coil connected to each turn number adjustment tap is different, where n is a positive integer. The adjustment switch has a fixed connection end and a turn number adjustment end. Among them, the fixed connection end of the bearing coil is connected to the fixed connection end of the adjustment switch. The turn number adjustment end of the adjustment switch can be connected to any one of the n turn number adjustment taps to adjust the number of turns of the bearing coil and obtain the current number of turns of the bearing coil.

[0094] Specifically, Figure 11 It is a schematic structural diagram of an embodiment where a controller controls the device for variable number of turns of the coil. As Figure 11 shown, when the controller controls the device for variable number of turns of the coil, the turn number adjustment switch 5 is controlled by the controller, and the number of turns of the coil 4 is changed through the turn number adjustment switch 5 to realize the adjustment of the number of turns of the bearing coil in the axial bearing.

[0095] In the solution of the present invention, a device for variable number of turns of the bearing coil (such as the device 3 for variable number of turns of the coil) is added to the magnetic levitation system. As Figure 11 can be seen, the device 3 for variable number of turns of the bearing coil is composed of two parts. The first part is a coil, and a pin is led out from each turn of the coil for connecting a toggle switch (such as the turn number adjustment switch 5). The second part is a toggle switch (such as the turn number adjustment switch 5), one end of which is connected to the controller 6 and is controlled by the controller 6, and the other end is connected to the corresponding coil joint according to the instruction of the controller 6. The device for variable number of turns of the bearing coil is used to solve the problem that the magnetic steel is demagnetized, the axial force becomes smaller, and then the current passing through the coil in the bearing is overprotected. When the axial force of the bearing is too small and the bearing cannot be axially attracted, the number of turns of the coil in the bearing is increased. At this time, the electromagnetic force range of the coil becomes larger, the axial force of the bearing becomes larger, and the bearing can be axially attracted to realize the floating of the rotor. However, if only the number of turns of the bearing coil is increased and the number of turns is uncontrollable, then the power consumption of the coil in the bearing will increase after the bearing floating is successful, resulting in waste of energy. Therefore, after the rotor axially floats successfully, the number of turns of the coil in the bearing is changed back to the original number of turns. In this way, by adding a device for variable number of turns of the bearing coil to the magnetic levitation system, the problem that the axial force of the bearing is insufficient due to the demagnetization of the magnetic steel in the bearing, resulting in the failure of the rotor to axially float, is avoided. At the same time, the power consumption of the coil in the bearing is reduced, the cost is saved, which greatly increases the reliability and adaptability of the magnetic levitation system.

[0096] For example, the inner coil of the axial bearing has a plurality of coil taps arranged in parallel. One of the coil taps located at the end of the inner coil of the axial bearing is the first connection end, and the remaining coil taps among the plurality of coil taps are n turns adjustment ends (n is a positive integer). For example, the inner coil of the axial bearing has a first connection end, a first turns adjustment end, a second turns adjustment end, a third turns adjustment end, and a fourth turns adjustment end. The turns adjustment switch 5 has a switch connection end and a switch adjustment end. The switch connection end of the turns adjustment switch 5 is connected to the first connection end of the inner coil of the axial bearing. The switch adjustment end of the turns adjustment switch 5 can be connected to any one of the turns adjustment ends among the first turns adjustment end, the second turns adjustment end, the third turns adjustment end, and the fourth turns adjustment end of the inner coil of the axial bearing. Among them, when the switch adjustment end of the turns adjustment switch 5 is connected to the first turns adjustment end of the inner coil of the axial bearing, the actual number of coil turns of the inner coil of the axial bearing is the first number of coil turns. When the switch adjustment end of the turns adjustment switch 5 is connected to the second turns adjustment end of the inner coil of the axial bearing, the actual number of coil turns of the inner coil of the axial bearing is the second number of coil turns, and the second number of coil turns is greater than the first number of coil turns. When the switch adjustment end of the turns adjustment switch 5 is connected to the third turns adjustment end of the inner coil of the axial bearing, the actual number of coil turns of the inner coil of the axial bearing is the third number of coil turns, and the third number of coil turns is greater than the second number of coil turns. When the switch adjustment end of the turns adjustment switch 5 is connected to the fourth turns adjustment end of the inner coil of the axial bearing, the actual number of coil turns of the inner coil of the axial bearing is the fourth number of coil turns, and the fourth number of coil turns is greater than the third number of coil turns.

[0097] Such as Figure 1 As shown, in the solution of the present invention, the control device of the magnetic levitation system includes: an acquisition unit 102 and a control unit 104.

[0098] Among them, the acquisition unit 102 is configured to acquire the number of coil turns of the bearing coil after the magnetic levitation system is powered on, and record it as the original number of coil turns of the bearing coil. The specific functions and processes of the acquisition unit 102 are described in step S110.

[0099] The control unit 104 is configured to control the coil turn number adjustable device to increase the original coil turn number of the bearing coil, and use the axial suction force of the axial bearing provided after the original coil turn number of the bearing coil becomes larger to control the axial floating of the rotor. Specifically, the coil turn number adjustable device is controlled to increase the original coil turn number of the bearing coil to obtain the current coil turn number of the bearing coil. And according to a preset axial floating mode, the axial suction force of the axial bearing provided by the bearing coil at the current coil turn number is used to control the axial floating of the rotor. The current coil turn number of the bearing coil is greater than the original coil turn number of the bearing coil. For the specific functions and processes of this control unit 104, refer to step S120.

[0100] In some embodiments, the control unit 104 controls the coil turn number adjustable device to increase the original coil turn number of the bearing coil, and uses the axial suction force of the axial bearing provided after the original coil turn number of the bearing coil becomes larger to control the axial floating of the rotor, including: a first control process of controlling the axial floating of the rotor by using the axial suction force of the axial bearing provided after the original coil turn number of the bearing coil becomes larger. Specifically, refer to the following exemplary description.

[0101] The control unit 104 is further specifically configured to determine whether there is a pre-stored initial coil turn number of the bearing coil after the magnetic levitation system is powered on. The initial coil turn number of the bearing coil is the coil turn number of the bearing coil when the current of the bearing coil does not exceed a preset overcurrent protection threshold and the rotor axially floats successfully after the magnetic levitation system is powered on last time. For the specific functions and processes of this control unit 104, also refer to step S210.

[0102] The control unit 104 is further specifically configured to, if there is a pre-stored initial coil turn number of the bearing coil, control the coil turn number adjustable device to make the original coil turn number of the bearing coil be the initial coil turn number of the bearing coil to obtain the current coil turn number of the bearing coil. Then, the axial suction force of the axial bearing provided by the bearing coil at the current coil turn number is used to control the axial floating of the rotor. For the specific functions and processes of this control unit 104, also refer to step S220.

[0103] The control unit 104 is further specifically configured to, if there is no pre-stored initial coil turn number of the bearing coil, use the original coil turn number of the bearing coil as the current coil turn number of the bearing coil. Then, the axial suction force of the axial bearing provided by the bearing coil at the current coil turn number is used to control the axial floating of the rotor. For the specific functions and processes of this control unit 104, also refer to step S230.

[0104] That is to say, if the initial number of turns of the bearing coil is pre-stored, the pre-stored initial number of turns of the bearing coil can be called. If the initial number of turns of the bearing coil is not pre-stored, the original number of turns of the bearing coil is used as the current number of turns of the bearing coil. In the case of obtaining the current number of turns of the bearing coil, the axial suction force of the axial bearing provided by the bearing coil at the current number of turns is used to control the axial floating of the rotor.

[0105] Combined with Figure 11 Taking the example shown, when the controller 6 of the magnetic levitation system is powered on to control the axial floating of the rotor, if the controller 6 detects that the bearing coil of the axial bearing is overcurrent, the controller 6 controls the toggle switch (such as the turn number adjustment switch 5) to change the turn number adjustment terminal 4 to increase the number of turns, and continues to control the axial floating of the rotor until the rotor axially floats and the controller detects that the bearing coil of the axial bearing does not have overcurrent. After the rotor axially floats successfully, this turn number data is stored in the EEPROM. When starting up and floating next time, the turn number is directly changed to this value. After floating successfully, the turn number is changed back to the initial value to avoid the increase and waste of the power consumption of the bearing coil.

[0106] In some embodiments, the control unit 104 controls the axial floating of the rotor by using the axial suction force of the axial bearing provided by the bearing coil at the current number of turns, including:

[0107] The control unit 104 is specifically further configured to control the rotor to start axial floating by using the axial suction force of the axial bearing provided by the bearing coil at the current number of turns according to a preset axial floating mode. For the specific functions and processes of this control unit 104, refer to step S310.

[0108] The control unit 104 is specifically further configured to obtain the actual position of the axial bearing during the process of controlling the axial floating of the rotor after controlling the rotor to start axial floating. For the specific functions and processes of this control unit 104, refer to step S320.

[0109] The control unit 104 is specifically further configured to determine whether the axial floating of the rotor is successful according to the actual position of the axial bearing during the process of controlling the axial floating of the rotor. For the specific functions and processes of this control unit 104, refer to step S330.

[0110] The control unit 104 is further specifically configured that if the axial floating of the rotor is not successful, it controls the coil turn number adjusting device to further increase the coil turn number of the bearing coil on the basis of the current coil turn number, so as to obtain the current coil turn number of the new bearing coil, thereby increasing the axial suction force of the axial bearing. The current coil turn number of the new bearing coil is greater than the current coil turn number of the bearing coil. For the specific functions and processing of this control unit 104, reference is also made to step S340.

[0111] The control unit 104 is further specifically configured to continue to control the axial floating of the rotor by using the axial suction force of the axial bearing that the new bearing coil can provide at the current coil turn number according to the floating mode. For the specific functions and processing of this control unit 104, reference is also made to step S350.

[0112] The control unit 104 is further specifically configured to perform such cyclic accumulation until the axial floating of the rotor is successful when the current of the bearing coil does not exceed the preset overcurrent protection threshold. For the specific functions and processing of this control unit 104, reference is also made to step S360.

[0113] Certainly, if the axial floating of the rotor is successful, it indicates that the current coil turn number of the bearing coil, i.e., the initial coil turn number of the bearing coil, can already meet the requirement of the axial floating of the rotor. Therefore, in this case, it is not necessary to further increase the coil turn number of the bearing coil on the basis of the current coil turn number.

[0114] See Figure 9 and Figure 10 As shown in the example, before the axial floating of the rotor, the axial bearing needs to be adsorbed to the set reference position. Therefore, when the magnetic levitation system is powered on and the rotor axially floats, the magnitude of the coil current in the axial bearing is determined according to the actual position of the axial bearing detected by the sensor. During the adjustment process, if the coil current in the axial bearing is greater than the protection threshold, the axial suction force of the axial bearing is increased by adjusting the coil turn number of the axial bearing. The increase in the coil turn number of the axial bearing can be achieved through an accumulation device until the coil current in the axial bearing does not exceed the protection threshold and the axial floating of the rotor is successful.

[0115] In some embodiments, the control unit 104 determines whether the axial floating of the rotor is successful according to the actual position of the axial bearing, including:

[0116] The control unit 104 is further specifically configured to determine the actual current of the bearing coil according to the actual position of the axial bearing. For the specific functions and processing of this control unit 104, reference is also made to step S410.

[0117] The control unit 104 is further specifically configured to determine whether the actual position of the axial bearing reaches a preset reference position, and determine whether the actual current of the bearing coil is greater than a preset overcurrent protection threshold. For the specific functions and processing of this control unit 104, refer to step S420.

[0118] The control unit 104 is further specifically configured to determine that the rotor axially floats successfully if it is determined that the actual position of the axial bearing has reached the preset reference position and the actual current of the bearing coil is less than or equal to the preset overcurrent protection threshold. For the specific functions and processing of this control unit 104, refer to step S430.

[0119] The control unit 104 is further specifically configured to determine that the rotor axially floats unsuccessfully if it is determined that the actual position of the axial bearing does not reach the preset reference position, and / or determine that the actual current of the bearing coil is greater than the preset overcurrent protection threshold. For the specific functions and processing of this control unit 104, refer to step S440.

[0120] Specifically, Figure 12 is a flowchart of an embodiment of the axial floating control device for a magnetic levitation bearing, specifically a schematic diagram of the floating process taking the axial direction as an example. A module for controlling the number of turns of the bearing coil is added to the control system program of the magnetic levitation system, and a function of storing the number of turns of the coil at the time of successful floating into the EEPROM module is added. As Figure 12 shown, the axial floating control device for a magnetic levitation bearing includes:

[0121] Step 1: Read the number of turns of the bearing coil in the axial bearing stored in the EEPROM module, denoted as the initial number of turns of the coil.

[0122] Step 2: During floating, the displacement sensor detects the actual position of the axial bearing and feeds it back to the control system of the magnetic levitation system. The control system of the magnetic levitation system determines the current magnitude of the bearing coil in the axial bearing according to the magnitude of the actual position of the axial bearing, and judges whether the rotor axially floats successfully: if so, execute Step 3, otherwise execute Step 4.

[0123] Step 3: After successful floating, store the number of turns of the coil at this time into the EEPROM, and directly call this number of turns of the coil when starting up and floating next time. After successful floating, through the coil number control program, restore the number of turns of the coil to the initial value to avoid the increase and loss of the power consumption of the bearing coil.

[0124] Step 4: If the axial floating cannot be completed with the initial number of turns of the bearing coil in the axial bearing, then the number of turns control program controls the number of turns of the coil at this time, and realizes the increase of the number of turns through an accumulation device, such as gradually increasing the number of turns of the axial bearing coil by using the accumulation method until the floating is successful.

[0125] In some embodiments, the control unit 104 controls the coil turn number adjustable device to increase the original coil turn number of the bearing coil, and uses the axial suction force of the axial bearing provided after the increase of the original coil turn number of the bearing coil to control the axial floating of the rotor. It further includes: a second control process of controlling the axial floating of the rotor by using the axial suction force of the axial bearing provided after the increase of the original coil turn number of the bearing coil. For specific details, reference can be made to the following exemplary description.

[0126] Specifically, the control unit 104 is further configured to, after the magnetic levitation system is powered on, control the coil turn number adjustable device to make the original coil turn number of the bearing coil be the maximum coil turn number of the bearing coil, so as to obtain the current coil turn number of the bearing coil. For the specific functions and processes of this control unit 104, reference is also made to step S610.

[0127] Specifically, the control unit 104 is further configured to, according to a preset axial floating mode, use the axial suction force of the axial bearing provided by the bearing coil at the current coil turn number to control the rotor to start axial floating until the axial floating of the rotor is successful. For the specific functions and processes of this control unit 104, reference is also made to step S620.

[0128] Specifically, the control unit 104 is further configured to, when the axial floating of the rotor is successful, restore the current coil turn number of the bearing coil to the original coil turn number of the bearing coil when the magnetic levitation system is powered on, and control the normal operation of the magnetic levitation system. For the specific functions and processes of this control unit 104, reference is also made to step S630.

[0129] Specifically, the solution of the present invention can pull the number of turns of the axial bearing coil to the maximum value when the magnetic levitation system is powered on for the first time, change the number of turns back to the initial value after successful floating, and this process is repeated every time the system is powered on.

[0130] The control unit 104 is further configured to, after the axial floating of the rotor is successful, control the coil turn number adjustable device to restore the current coil turn number of the bearing coil to the original coil turn number of the bearing coil, that is, to the coil turn number of the bearing coil when the magnetic levitation system is powered on. Wherein, the current coil turn number of the bearing coil is the coil turn number that can make the axial floating of the rotor successful after the increase of the original coil turn number of the bearing coil. For the specific functions and processes of this control unit 104, reference is also made to step S130.

[0131] A control device for a magnetic levitation system provided by the solution of the present invention adds a device with variable number of turns of the bearing coil to the magnetic levitation control system. After adding the device with variable number of turns of the bearing coil, when the rotor floats axially and the bearing force is too small due to the demagnetization of the permanent magnet in the bearing and the rotor cannot complete axial floating, and if the current passing through the coil in the bearing is continuously increased, it will cause overcurrent protection. In this case, the number of turns of the bearing coil is increased by the device with variable number of turns of the bearing coil, so that the suction range of the bearing becomes larger, the overall suction of the bearing increases, and the axial force required for the rotor to float axially can be satisfied. Thus, the problem that the rotor cannot float due to the inability of the bearing to attract in all directions during the demagnetization and floating of the permanent magnet in the bearing can be effectively solved. Furthermore, the problem that multiple floating failures of the rotor will cause wear, shaft collision and other phenomena of components such as the rotor and the bearing in the magnetic levitation system, which will seriously affect the magnetic levitation system, can be avoided. And after the floating is successful, the number of turns is restored to the initial value to avoid the increase and waste of the power consumption of the bearing coil.

[0132] In some embodiments, the control unit 104, after the rotor axially floats successfully, controls the coil turn number adjustable device to restore the current turn number of the bearing coil to the original turn number of the bearing coil, including:

[0133] The control unit 104 is specifically further configured to, when the current of the bearing coil does not exceed the preset overcurrent protection threshold and the rotor axially floats successfully, restore the current turn number of the bearing coil or the current turn number of the new bearing coil to the original turn number of the bearing coil when the magnetic levitation system is powered on, and control the normal operation of the magnetic levitation system. For the specific functions and processes of this control unit 104, refer to step S510. And,

[0134] The control unit 104 is specifically further configured to, when there is a current turn number of the new bearing coil, determine the current turn number of the new bearing coil as the initial turn number of the new bearing coil, so as to control the axial floating of the rotor according to the initial turn number of the new bearing coil after the magnetic levitation system is powered on next time. For the specific functions and processes of this control unit 104, refer to step S520.

[0135] In this way, the solution of the present invention, by adding a device for varying the number of turns of the axial bearing coil, specifically adding a device for varying the number of turns of the axial bearing coil to the internal coil of the axial bearing, can change the number of turns of the internal coil of the axial bearing to improve the adaptability of the magnetic levitation system. Specifically, when the rotor of the magnetic levitation system starts up and axially levitates, due to various reasons such as the demagnetization of the permanent magnet in the bearing, the bearing force of the bearing during levitation is not sufficient to attract the rotor, resulting in the failure of the rotor to successfully levitate. After adding the device for varying the number of turns of the axial bearing coil, when the bearing force of the original number of turns of the bearing coil is insufficient, the number of turns of the bearing coil is gradually increased by the cumulative method until the rotor successfully levitates. After the rotor successfully levitates, the number of turns of the bearing coil is adjusted back to the initial value to reduce the power consumption of the bearing coil, and the number value of the number of turns of the bearing coil in the case of successful rotor levitation is stored in a memory (such as EEPROM). When the rotor of the magnetic levitation system starts up and axially levitates next time, this number of turns is directly used for levitation, saving the levitation process and ensuring the reliability of levitation.

[0136] Since the processing and functions implemented by the device of this embodiment are basically corresponding to the embodiments, principles and examples of the foregoing method, for the details not described in the description of this embodiment, reference may be made to the relevant descriptions in the foregoing embodiments and will not be elaborated herein.

[0137] By adopting the technical solution of the present invention, by installing a device for varying the number of turns of the coil on the internal coil of the axial bearing of the magnetic levitation bearing, when the rotor axially levitates after the magnetic levitation system starts up and the initial number of turns of the internal coil of the axial bearing cannot complete the axial levitation of the rotor, the number of turns of the internal coil of the axial bearing is increased in an accumulative manner by the device for varying the number of turns of the coil until the axial levitation of the rotor is successful. After the axial levitation of the rotor is successful, the number of turns of the internal coil of the axial bearing is restored to the initial number of turns by the device for varying the number of turns of the coil. By the device for varying the number of turns of the coil, the problem that the insufficient axial force of the bearing caused by the demagnetization of the permanent magnet in the bearing leads to the failure of the axial levitation of the rotor is avoided, and at the same time, the power consumption of the coil in the bearing is reduced and the cost is saved.

[0138] According to an embodiment of the present invention, there is also provided a magnetic levitation system corresponding to a control device of a magnetic levitation system. The magnetic levitation system may include: the control device of the magnetic levitation system described above.

[0139] Since the processing and functions implemented by the magnetic levitation system of this embodiment are basically corresponding to the embodiments, principles and examples of the foregoing device, for the details not described in the description of this embodiment, reference may be made to the relevant descriptions in the foregoing embodiments and will not be elaborated herein.

[0140] By adopting the technical solution of the present invention, a device with variable number of turns is added to the internal coil of the axial bearing of the magnetic levitation bearing. When the rotor axially floats after the magnetic levitation system is powered on, if the initial number of turns of the internal coil of the axial bearing cannot complete the axial floating of the rotor, the device with variable number of turns increases the number of turns of the internal coil of the axial bearing in an accumulative manner until the axial floating of the rotor is successful. After the axial floating of the rotor is successful, the device with variable number of turns restores the number of turns of the internal coil of the axial bearing to the initial number of turns. Increasing the number of turns of the coil in the bearing makes the electromagnetic force range of the coil larger at this time, and the axial force of the bearing becomes larger, so that the bearing can axially attract and realize the floating of the rotor.

[0141] According to an embodiment of the present invention, there is also provided a storage medium corresponding to the control method of the magnetic levitation system. The storage medium includes a stored program, wherein when the program runs, it controls the device where the storage medium is located to execute the control method of the magnetic levitation system described above.

[0142] Since the processing and functions implemented by the storage medium of this embodiment are basically corresponding to the embodiments, principles and examples of the foregoing method, for the parts not described in detail in the description of this embodiment, reference can be made to the relevant descriptions in the foregoing embodiments, and details will not be repeated here.

[0143] By adopting the technical solution of the present invention, a device with variable number of turns is added to the internal coil of the axial bearing of the magnetic levitation bearing. When the rotor axially floats after the magnetic levitation system is powered on, if the initial number of turns of the internal coil of the axial bearing cannot complete the axial floating of the rotor, the device with variable number of turns increases the number of turns of the internal coil of the axial bearing in an accumulative manner until the axial floating of the rotor is successful. After the axial floating of the rotor is successful, the device with variable number of turns restores the number of turns of the internal coil of the axial bearing to the initial number of turns. By using the device with variable number of turns of the bearing coil to increase the number of turns of the bearing coil, the suction range of the bearing is made larger, so that the overall suction of the bearing increases, which can meet the axial force required for the axial floating of the rotor and realize the floating of the rotor.

[0144] In summary, it is easy for those skilled in the art to understand that, on the premise of no conflict, the above advantageous ways can be freely combined and superimposed.

[0145] The above are only embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the scope of the claims of the present invention.

Claims

1. A control method for a magnetic levitation system, characterized in that, the magnetic levitation system includes: a magnetic levitation bearing and a rotor; inside the axial bearing of the magnetic levitation bearing, a bearing coil and a coil turn number adjustable device are provided; the coil turn number adjustable device can adjust the number of turns of the bearing coil to obtain the current number of turns of the bearing coil; the control method for the magnetic levitation system includes: after the magnetic levitation system is powered on, obtain the number of turns of the bearing coil, denoted as the original number of turns of the bearing coil; control the coil turn number adjustable device to increase the original number of turns of the bearing coil, and use the axial suction force of the axial bearing provided after the original number of turns of the bearing coil is increased to control the axial floating of the rotor; after the axial floating of the rotor is successful, control the coil turn number adjustable device to restore the current number of turns of the bearing coil to the original number of turns of the bearing coil; increase the number of turns of the internal coil of the axial bearing in an accumulative manner through the coil turn number variable device until the axial floating of the rotor is successful.

2. The control method for the magnetic levitation system according to claim 1, characterized in that, the bearing coil turn number adjustable device includes: a bearing coil and an adjustment switch; the bearing coil has a fixed connection end and n turn number adjustment taps, and the number of turns of the coil connected to each turn number adjustment tap is different, where n is a positive integer; the adjustment switch has a fixed connection end and a turn number adjustment end; wherein, the fixed connection end of the bearing coil is connected to the fixed connection end of the adjustment switch; the turn number adjustment end of the adjustment switch can be connected to any one of the n turn number adjustment taps to adjust the number of turns of the bearing coil to obtain the current number of turns of the bearing coil.

3. The control method for the magnetic levitation system according to claim 1 or 2, characterized in that, controlling the coil turn number adjustable device to increase the original number of turns of the bearing coil, and using the axial suction force of the axial bearing provided after the original number of turns of the bearing coil is increased to control the axial floating of the rotor includes: determine whether there is a pre-stored initial number of turns of the bearing coil; wherein, the initial number of turns of the bearing coil is the number of turns of the bearing coil when the current of the bearing coil does not exceed the preset overcurrent protection threshold and the axial floating of the rotor is successful after the magnetic levitation system is powered on last time; if there is a pre-stored initial number of turns of the bearing coil, then control the coil turn number adjustable device to make the original number of turns of the bearing coil be the initial number of turns of the bearing coil to obtain the current number of turns of the bearing coil, and then use the axial suction force of the axial bearing provided by the bearing coil at the current number of turns to control the axial floating of the rotor; If there is no pre-stored initial number of turns of the bearing coil, the original number of turns of the bearing coil is used as the current number of turns of the bearing coil. Thereafter, the axial floating of the rotor is controlled by using the axial suction force of the axial bearing that can be provided by the bearing coil at the current number of turns.

4. The control method of the magnetic levitation system according to claim 3, wherein, controlling the axial floating of the rotor by using the axial suction force of the axial bearing that can be provided by the bearing coil at the current number of turns includes: According to a preset axial floating mode, controlling the rotor to start axial floating by using the axial suction force of the axial bearing that can be provided by the bearing coil at the current number of turns; During the process of controlling the axial floating of the rotor, obtaining the actual position of the axial bearing; Determining whether the axial floating of the rotor is successful according to the actual position of the axial bearing; If the axial floating of the rotor is not successful, controlling the coil turn number adjustable device to further increase the number of turns of the bearing coil on the basis of the current number of turns to obtain the new current number of turns of the bearing coil; Continuing to control the axial floating of the rotor by using the axial suction force of the axial bearing that can be provided by the new bearing coil at the current number of turns; Accumulating in this cycle until the axial floating of the rotor is successful when the current of the bearing coil does not exceed the preset overcurrent protection threshold.

5. The control method of the magnetic levitation system according to claim 4, wherein, Determining whether the axial floating of the rotor is successful according to the actual position of the axial bearing includes: Determining the actual current of the bearing coil according to the actual position of the axial bearing; Determining whether the actual position of the axial bearing reaches a preset reference position and determining whether the actual current of the bearing coil is greater than a preset overcurrent protection threshold; If it is determined that the actual position of the axial bearing has reached the preset reference position and the actual current of the bearing coil is less than or equal to the preset overcurrent protection threshold, it is determined that the axial floating of the rotor is successful; If it is determined that the actual position of the axial bearing does not reach the preset reference position, and / or it is determined that the actual current of the bearing coil is greater than the preset overcurrent protection threshold, it is determined that the axial floating of the rotor is not successful.

6. The control method of the magnetic levitation system according to claim 3, wherein, After the axial floating of the rotor is successful, controlling the coil turn number adjustable device to restore the current number of turns of the bearing coil to the original number of turns of the bearing coil, including: When the current of the bearing coil does not exceed the preset overcurrent protection threshold and the axial floating of the rotor is successful, restoring the current number of turns of the bearing coil or the new current number of turns of the bearing coil to the original number of turns of the bearing coil of the magnetic levitation system when it is powered on, and controlling the normal operation of the magnetic levitation system; and, In the case of having the current number of turns of the new bearing coil, determine the current number of turns of the new bearing coil as the initial number of turns of the new bearing coil, so as to control the axial floating of the rotor according to the initial number of turns of the new bearing coil after the magnetic levitation system is powered on next time.

7. The control method of the magnetic levitation system according to claim 1 or 2, characterized in that controlling the coil turn number adjustable device to increase the original number of turns of the bearing coil, and using the axial suction force of the axial bearing provided after the original number of turns of the bearing coil becomes larger to control the axial floating of the rotor, further comprising: after the magnetic levitation system is powered on, controlling the coil turn number adjustable device to make the original number of turns of the bearing coil be the maximum number of turns of the bearing coil, and obtaining the current number of turns of the bearing coil; according to a preset axial floating mode, using the axial suction force of the axial bearing provided by the bearing coil at the current number of turns to control the rotor to start axial floating and make the axial floating of the rotor successful.

8. A control device of a magnetic levitation system, characterized in that the magnetic levitation system includes a magnetic levitation bearing and a rotor; inside the axial bearing of the magnetic levitation bearing, a bearing coil and a coil turn number adjustable device are provided; the coil turn number adjustable device can adjust the number of turns of the bearing coil to obtain the current number of turns of the bearing coil; the control device of the magnetic levitation system includes: an acquisition unit configured to acquire the number of turns of the bearing coil after the magnetic levitation system is powered on, and record it as the original number of turns of the bearing coil; a control unit configured to control the coil turn number adjustable device to increase the original number of turns of the bearing coil, and use the axial suction force of the axial bearing provided after the original number of turns of the bearing coil becomes larger to control the axial floating of the rotor; the control unit is further configured to, after the axial floating of the rotor is successful, control the coil turn number adjustable device to make the current number of turns of the bearing coil return to the original number of turns of the bearing coil; increase the number of turns of the internal coil of the axial bearing in an accumulative manner through the coil turn number variable device until the axial floating of the rotor is successful.

9. The control device of the magnetic levitation system according to claim 8, characterized in that the bearing coil turn number adjustable device includes a bearing coil and an adjustment switch; the bearing coil has a fixed connection end and n turn number adjustment taps, and the number of turns of the coil connected to each turn number adjustment tap is different, where n is a positive integer; the adjustment switch has a fixed connection end and a turn number adjustment end; wherein, the fixed connection end of the bearing coil is connected to the fixed connection end of the adjustment switch; the turn number adjustment end of the adjustment switch can be connected to any one of the n turn number adjustment taps to adjust the number of turns of the bearing coil to obtain the current number of turns of the bearing coil.

10. The control device of the magnetic levitation system according to claim 8 or 9, characterized in that, the control unit controls the coil turn number adjustable device to increase the original coil turn number of the bearing coil, and uses the axial suction force of the axial bearing provided after the increase of the original coil turn number of the bearing coil to control the axial floating of the rotor, including: determining whether there is a pre-stored initial coil turn number of the bearing coil; wherein, the initial coil turn number of the bearing coil is the coil turn number of the bearing coil when the current of the bearing coil does not exceed a preset overcurrent protection threshold and the axial floating of the rotor is successful after the magnetic levitation system is powered on last time; if there is a pre-stored initial coil turn number of the bearing coil, then control the coil turn number adjustable device to make the original coil turn number of the bearing coil be the initial coil turn number of the bearing coil to obtain the current coil turn number of the bearing coil, and then use the axial suction force of the axial bearing provided by the bearing coil at the current coil turn number to control the axial floating of the rotor; if there is no pre-stored initial coil turn number of the bearing coil, then take the original coil turn number of the bearing coil as the current coil turn number of the bearing coil, and then use the axial suction force of the axial bearing provided by the bearing coil at the current coil turn number to control the axial floating of the rotor.

11. The control device of the magnetic levitation system according to claim 10, characterized in that, the control unit uses the axial suction force of the axial bearing provided by the bearing coil at the current coil turn number to control the axial floating of the rotor, including: controlling the rotor to start axial floating by using the axial suction force of the axial bearing provided by the bearing coil at the current coil turn number according to a preset axial floating mode; acquiring the actual position of the axial bearing during the process of controlling the axial floating of the rotor; determining whether the axial floating of the rotor is successful according to the actual position of the axial bearing; if the axial floating of the rotor is not successful, then control the coil turn number adjustable device to continue to increase the coil turn number of the bearing coil on the basis of the current coil turn number to obtain a new current coil turn number of the bearing coil; using the axial suction force of the axial bearing provided by the new bearing coil at the current coil turn number to continue to control the axial floating of the rotor; accumulating in this cycle until the axial floating of the rotor is successful under the condition that the current of the bearing coil does not exceed the preset overcurrent protection threshold.

12. The control device of the magnetic levitation system according to claim 11, characterized in that, the control unit determines whether the axial floating of the rotor is successful according to the actual position of the axial bearing, including: determining the actual current of the bearing coil according to the actual position of the axial bearing; determining whether the actual position of the axial bearing reaches a preset reference position and determining whether the actual current of the bearing coil is greater than a preset overcurrent protection threshold; If it is determined that the actual position of the axial bearing has reached the preset reference position and the actual current of the bearing coil is less than or equal to the preset overcurrent protection threshold, it is determined that the rotor axially floats successfully; If it is determined that the actual position of the axial bearing has not reached the preset reference position, and / or it is determined that the actual current of the bearing coil is greater than the preset overcurrent protection threshold, it is determined that the rotor axially floats unsuccessfully.

13. The control device of the magnetic levitation system according to claim 10, characterized in that after the rotor axially floats successfully, the control unit controls the coil turn number adjustable device to restore the current turn number of the bearing coil to the original turn number of the bearing coil, including: when the current of the bearing coil does not exceed the preset overcurrent protection threshold and the rotor axially floats successfully, restoring the current turn number of the bearing coil or the current turn number of the new bearing coil to the original turn number of the bearing coil when the magnetic levitation system is powered on, and controlling the normal operation of the magnetic levitation system; and, when there is a current turn number of the new bearing coil, determining the current turn number of the new bearing coil as the initial turn number of the new bearing coil, so as to control the axial floating of the rotor according to the initial turn number of the new bearing coil after the magnetic levitation system is powered on next time.

14. The control device of the magnetic levitation system according to claim 8 or 9, characterized in that the control unit controls the coil turn number adjustable device to increase the original turn number of the bearing coil, and uses the axial suction force of the axial bearing provided by the increased original turn number of the bearing coil to control the axial floating of the rotor, and further includes: after the magnetic levitation system is powered on, controlling the coil turn number adjustable device to make the original turn number of the bearing coil the maximum turn number of the bearing coil, and obtaining the current turn number of the bearing coil; according to the preset axial floating mode, using the axial suction force of the axial bearing provided by the bearing coil at the current turn number to control the rotor to start axial floating, so that the rotor axially floats successfully.

15. A magnetic levitation system, characterized in that it includes: the control device of the magnetic levitation system according to any one of claims 8 to 14.

16. A storage medium, characterized in that the storage medium includes a stored program, wherein when the program runs, it controls the device where the storage medium is located to execute the control method of the magnetic levitation system according to any one of claims 1 to 7.

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