Online automatic calibration method and device for active magnetic suspension bearing gap sensor

Abstract

The invention relates to an online automatic calibration method and device for an active magnetic suspension bearing clearance sensor. The method comprises the following steps: controlling a radial electromagnet on a radial bearing in an active magnetic suspension bearing to output according to preset first and second adjusting currents, attracting a rotor to one side close to or far away from a radial clearance sensor to move back and forth, and obtaining a minimum or maximum sampling value output by the radial clearance sensor; controlling an axial electromagnet on an axial bearing in the active magnetic suspension bearing to output according to a preset third adjusting current, attracting a rotor to one side close to or far away from an axial gap sensor, and obtaining a minimum or maximum sampling value output by the axial gap sensor; and performing linear fitting on a sampling result and a corresponding actual gap value by adopting a least square method to obtain a linear relationship between the sampling value of the radial or axial gap sensor and the actual gap value, and completing online automatic calibration of the radial or axial gap sensor of the active magnetic suspension bearing.

Description

Technical Field

[0001] The present application relates to the technical field of gap sensor calibration, and in particular to an online automatic calibration method and device for an active magnetic bearing gap sensor. Background Art

[0002] Magnetic bearings use magnetic force to suspend the rotor in the air, achieving a new type of high-performance bearing without any mechanical contact between the rotor and the stator. They are the first choice of support technology in the current high-speed, vacuum, ultra-clean and heavy-load fields. They can be used in blowers, centrifugal pumps, electric spindles, high-speed motors, etc., and have broad application prospects in the oil and gas, mechanical processing, turbomachinery, aerospace, energy, semiconductors, medical and other industries.

[0003] At present, the research on magnetic bearings is very in-depth, among which active magnetic bearings based on electromagnet control are one of the current research hotspots and have broad application prospects in various industries. Active magnetic bearings use electromagnets to control five degrees of freedom except axial rotation, and it is necessary to collect the gap data between the rotor and the stator in five directions in real time. Inductive or eddy current sensors are usually used to sense the gap data, but these sensors will have errors in the gap data after being used for a period of time due to various reasons such as mechanical wear, temperature changes, and changes in the characteristics of sensor parts, and need to be recalibrated. However, the process of disassembling the sensor for manual calibration is time-consuming and laborious. Summary of the invention

[0004] Based on this, it is necessary to provide an online automatic calibration method and device for the gap sensor of an active magnetic bearing, which can perform online automatic calibration of the gap sensor during the use of the active magnetic bearing without removing the gap sensor from the active magnetic bearing.

[0005] An online automatic calibration method for an active magnetic bearing gap sensor, the method is controlled by a host computer, and the specific steps of the method include:

[0006] For an active magnetic bearing in which gap sensors and electromagnets are alternately arranged, the radial electromagnets on the radial bearings in the active magnetic bearings are controlled to output according to a preset first regulating current and a second regulating current, so that the rotor is attracted to a side close to or away from the radial gap sensor to move back and forth, and the minimum sampling value or the maximum sampling value output by the radial gap sensor is obtained during the back and forth movement of the rotor;

[0007] According to a preset third regulating current, the axial electromagnet on the axial bearing in the active magnetic bearing is controlled to output, so as to attract the rotor to a side close to or away from the axial gap sensor, and obtain a minimum sampling value or a maximum sampling value output by the axial gap sensor;

[0008] According to the minimum sampling value, the maximum sampling value and the corresponding actual gap value, the least square method is used for linear fitting to obtain the linear relationship between the radial or axial gap sensor sampling value and the actual gap value, thereby completing the online automatic calibration of the radial or axial gap sensor of the active magnetic bearing.

[0009] In one embodiment, four groups of symmetrically arranged radial electromagnets, a radial X-direction gap sensor probe and a radial Y-direction gap sensor probe are provided on the radial bearing of the active magnetic bearing, and the two gap sensor probes are staggered at 90 degrees between the radial electromagnets.

[0010] In one embodiment, a radial electromagnet on a radial bearing in an active magnetic bearing is controlled to output according to a preset first regulating current and a second regulating current, so that the rotor is attracted to a side close to or away from a radial gap sensor to move back and forth, and a minimum sampling value or a maximum sampling value output by the radial gap sensor is obtained during the back and forth movement of the rotor, including:

[0011] According to the preset first regulating current, the radial electromagnet on the radial bearing is controlled to output, so as to attract the rotor to a side close to or away from the radial X-direction gap sensor probe to move back and forth, and the minimum sampling value or the maximum sampling value of the radial X-direction gap sensor output is obtained during the back and forth movement of the rotor;

[0012] The radial electromagnet on the radial bearing is controlled to output according to the preset second regulating current, so as to attract the rotor to move back and forth close to or away from the side of the radial Y-direction gap sensor probe, and obtain the minimum sampling value or the maximum sampling value of the radial Y-direction gap sensor output during the back and forth movement of the rotor.

[0013] In one embodiment, the radial electromagnet on the radial bearing is controlled to output according to a preset first regulating current, so as to attract the rotor to a side close to or away from the radial X-direction gap sensor probe to move back and forth, and the minimum sampling value or the maximum sampling value of the radial X-direction gap sensor output is obtained during the back and forth movement of the rotor, including:

[0014] Synchronously passing the initial value of the first regulating current into two groups of radial electromagnets close to or away from the radial X-direction gap sensor probe, thereby attracting the rotor to the side close to or away from the radial X-direction gap sensor probe;

[0015] After the first regulating current passed through the two groups of radial electromagnets close to or away from the radial X-direction gap sensor probe is increased to the maximum value in sequence, the first regulating current passed through the two groups of radial electromagnets close to or away from the radial X-direction gap sensor probe is restored to the initial value in sequence, so that the rotor moves back and forth along the Y-axis direction on the side close to or away from the radial X-direction gap sensor probe, and the minimum sampling value or the maximum sampling value output by the radial X-direction gap sensor is obtained during the back and forth movement of the rotor.

[0016] In one embodiment, the radial electromagnet on the radial bearing is controlled to output according to the preset second regulating current, so as to attract the rotor to a side close to or away from the radial Y-direction gap sensor probe to move back and forth, and the minimum sampling value or the maximum sampling value of the radial Y-direction gap sensor output is obtained during the back and forth movement of the rotor, including:

[0017] Synchronously passing the initial value of the second regulating current into two groups of radial electromagnets close to or away from the radial Y-direction gap sensor probe, thereby attracting the rotor to the side close to or away from the radial Y-direction gap sensor probe;

[0018] After the second regulating current passed through the two groups of radial electromagnets close to or away from the radial Y-direction gap sensor probe is increased to the maximum value in turn, the second regulating current passed through the two groups of radial electromagnets close to or away from the radial Y-direction gap sensor probe is restored to the initial value in turn, so that the rotor moves back and forth along the X-axis direction on the side close to or away from the radial Y-direction gap sensor probe, and the minimum sampling value or the maximum sampling value output by the radial Y-direction gap sensor is obtained during the back-and-forth movement of the rotor.

[0019] In one of the embodiments, a group of axial electromagnets and an axial Z-direction gap sensor probe are disposed on the axial bearing of the active magnetic bearing, and the axial Z-direction gap sensor probe is arranged opposite to the axial electromagnet.

[0020] In one embodiment, the axial electromagnet on the axial bearing in the active magnetic bearing is controlled to output according to a preset third regulating current, so as to attract the rotor to a side close to or away from the axial gap sensor, and obtain the minimum sampling value or the maximum sampling value output by the axial gap sensor, including:

[0021] The axial electromagnet on the axial bearing in the active magnetic bearing is controlled to output according to a preset third regulating current, and when the axial electromagnet has no output and the rotor is attracted to a side close to the axial Z-direction gap sensor probe, a minimum sampling value of the axial Z-direction gap sensor output is obtained;

[0022] When the axial electromagnet outputs a large amount and the rotor is attracted to a side away from the axial Z-direction gap sensor probe, the maximum sampling value of the axial Z-direction gap sensor output is obtained.

[0023] In one embodiment, according to the minimum sampling value, the maximum sampling value and the corresponding actual gap value, the least square method is used to perform linear fitting to obtain the linear relationship between the radial or axial gap sensor sampling value and the actual gap value, and the online automatic calibration of the radial or axial gap sensor of the active magnetic bearing is completed, including:

[0024] According to the minimum sampling value and the maximum sampling value outputted by the radial X-direction gap sensor multiple times and the corresponding actual gap value, the least square method is used for linear fitting to obtain the linear relationship between the radial X-direction gap sensor sampling value and the actual gap value, thereby completing the online automatic calibration of the radial X-direction gap sensor;

[0025] According to the minimum sampling value and the maximum sampling value outputted by the radial Y-direction gap sensor multiple times and the corresponding actual gap value, the least square method is used for linear fitting to obtain the linear relationship between the radial Y-direction gap sensor sampling value and the actual gap value, thereby completing the online automatic calibration of the radial Y-direction gap sensor;

[0026] According to the minimum sampling value and the maximum sampling value output by the axial Z-direction gap sensor multiple times and the corresponding actual gap value, the least squares method is used for linear fitting to obtain the linear relationship between the axial Z-direction gap sensor sampling value and the actual gap value, thereby completing the online automatic calibration of the axial Z-direction gap sensor.

[0027] In one embodiment, the radial electromagnet and the axial electromagnet are each composed of two coils.

[0028] An online automatic calibration device for an active magnetic bearing gap sensor, the device comprising:

[0029] A radial gap sensor sampling module is used for an active magnetic bearing in which gap sensors and electromagnets are alternately arranged, and controls the radial electromagnets on the radial bearings in the active magnetic bearings to output according to a preset first regulating current and a second regulating current, so as to attract the rotor to a side close to or away from the radial gap sensor to move back and forth, and obtain the minimum sampling value or the maximum sampling value output by the radial gap sensor during the back and forth movement of the rotor;

[0030] An axial clearance sensor sampling module is used to control the axial electromagnet on the axial bearing in the active magnetic bearing to output according to a preset third regulating current, so as to attract the rotor to a side close to or away from the axial clearance sensor, and obtain a minimum sampling value or a maximum sampling value output by the axial clearance sensor;

[0031] The online automatic calibration module is used to perform linear fitting using the least squares method according to the minimum sampling value, the maximum sampling value and the corresponding actual gap value, to obtain the linear relationship between the radial or axial gap sensor sampling value and the actual gap value, and complete the online automatic calibration of the radial or axial gap sensor of the active magnetic bearing.

[0032] The above-mentioned online automatic calibration method for the gap sensor of an active magnetic bearing has the following technical effects:

[0033] 1. This method has high calibration accuracy. During the calibration process, it is ensured that the actual maximum / minimum value of the gap in each direction of the active magnetic bearing can be sampled. The accuracy of the gap sensor after calibration can reach 10 -7 Meter level;

[0034] 2. This method is easy and quick to implement. There is no need to remove the gap sensor from the active magnetic bearing. You only need to issue a calibration command on the host computer to obtain the calibrated gap sensor parameters with one click, without manual operation or calculation.

[0035] 3. The implementation of this method consumes very little time and money, only about 1 minute, and the economic consumption is negligible. No additional equipment is required, and it can meet the needs of calibrating the gap sensor after each start-up of the magnetic bearing, ensuring the high-precision operation of the magnetic bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A schematic diagram of a flow chart of an online automatic calibration method for an active magnetic bearing gap sensor in one embodiment;

[0037] Figure 2 A schematic diagram of the arrangement of a radial bearing in an active magnetic bearing in which gap sensors and electromagnets are alternately arranged in one embodiment;

[0038] Figure 3 A schematic diagram of the steps of obtaining the maximum sampling value output by the radial X-direction gap sensor according to an embodiment; Figure 3 (a) is a schematic diagram of the movement state of the rotor when no current is passed through the radial electromagnets A2 and A3, and 1.5A current is passed through the radial electromagnets A1 and A4 at the same time; Figure 3 (b) is a schematic diagram of the movement state of the rotor when no current is passed through the radial electromagnets A2 and A3, a 2.0A current is passed through the radial electromagnet A1, and a 1.5A current is passed through the radial electromagnet A4; Figure 3 (c) is a schematic diagram of the movement state of the rotor when no current is passed through the radial electromagnets A2 and A3, and 2.0A current is passed through the radial electromagnets A1 and A4 at the same time; Figure 3(d) is a schematic diagram of the movement state of the rotor when no current is passed through the radial electromagnets A2 and A3, a current of 1.5 A is passed through the radial electromagnet A1, and a current of 2.0 A is passed through the radial electromagnet A4;

[0039] Figure 4 A schematic diagram of a process of online automatic calibration of a multi-directional gap sensor in one embodiment;

[0040] Figure 5 The figure is a schematic diagram of the linear relationship between the radial X-direction gap sensor sampling value and the actual gap value obtained by least squares fitting in one embodiment. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0042] In one embodiment, Figure 1 As shown, an online automatic calibration method for an active magnetic bearing gap sensor is provided, the method is controlled by a host computer, and the specific steps of the method include:

[0043] Step S1, for an active magnetic bearing in which gap sensors and electromagnets are alternately arranged, the radial electromagnets on the radial bearings in the active magnetic bearings are controlled to output according to the preset first adjustment current and the second adjustment current, so as to attract the rotor to the side close to or away from the radial gap sensor to move back and forth, and obtain the minimum sampling value or the maximum sampling value output by the radial gap sensor during the back and forth movement of the rotor.

[0044] Step S2, controlling the axial electromagnet on the axial bearing in the active magnetic bearing to output according to the preset third regulating current, attracting the rotor to the side close to or away from the axial gap sensor, and obtaining the minimum sampling value or the maximum sampling value output by the axial gap sensor.

[0045] Step S3, according to the minimum sampling value, the maximum sampling value and the corresponding actual gap value, the least squares method is used for linear fitting to obtain the linear relationship between the radial or axial gap sensor sampling value and the actual gap value, and the online automatic calibration of the radial or axial gap sensor of the active magnetic bearing is completed.

[0046] In one embodiment, if Figure 2As shown, the radial bearing of the active magnetic bearing is provided with four groups of radial electromagnets A1-A4 composed of eight coils 31-38, a radial X-direction gap sensor probe 30 and a radial Y-direction gap sensor probe 39, which are symmetrically arranged around the rotor 40, and the two gap sensor probes are staggered at 90 degrees between the radial electromagnets. Thus, a rectangular coordinate system XOY is set, and the origin O of the coordinate system is the center of the circle surrounded by the four groups of radial electromagnets A1-A4.

[0047] In one embodiment, a radial electromagnet on a radial bearing in an active magnetic bearing is controlled to output according to a preset first regulating current and a second regulating current, so that the rotor is attracted to a side close to or away from a radial gap sensor to move back and forth, and a minimum sampling value or a maximum sampling value output by the radial gap sensor is obtained during the back and forth movement of the rotor, including:

[0048] According to the preset first regulating current, the radial electromagnet on the radial bearing is controlled to output, so as to attract the rotor to a side close to or away from the radial X-direction gap sensor probe to move back and forth, and the minimum sampling value or the maximum sampling value of the radial X-direction gap sensor output is obtained during the back and forth movement of the rotor;

[0049] The radial electromagnet on the radial bearing is controlled to output according to the preset second regulating current, so as to attract the rotor to move back and forth close to or away from the side of the radial Y-direction gap sensor probe, and obtain the minimum sampling value or the maximum sampling value of the radial Y-direction gap sensor output during the back and forth movement of the rotor.

[0050] It can be understood that since there are multiple sets of radial electromagnets on the radial bearing, there are assembly errors between the radial electromagnets. When the rotor is attracted to the side close to or far away from the radial clearance sensor, the rotor is not necessarily at the position closest to or farthest from the radial clearance sensor, that is, the radial clearance sensor may not sample the true minimum or maximum value at this time. Therefore, in order to ensure that the radial clearance sensor samples the true minimum or maximum value, the rotor is controlled to move back and forth near the position closest to or farthest from the radial clearance sensor by adjusting the current, ensuring that the rotor must pass through the position closest to or farthest from the radial clearance sensor during this process, ensuring that the radial clearance sensor can definitely sample the true minimum or maximum value, thereby improving the calibration accuracy of the sensor.

[0051] In one embodiment, the radial electromagnet on the radial bearing is controlled to output according to a preset first regulating current, so as to attract the rotor to a side close to or away from the radial X-direction gap sensor probe to move back and forth, and the minimum sampling value or the maximum sampling value of the radial X-direction gap sensor output is obtained during the back and forth movement of the rotor, including:

[0052] Synchronously passing the initial value of the first regulating current into two groups of radial electromagnets close to or away from the radial X-direction gap sensor probe, thereby attracting the rotor to the side close to or away from the radial X-direction gap sensor probe;

[0053] After the first regulating current passed through the two groups of radial electromagnets close to or away from the radial X-direction gap sensor probe is increased to the maximum value in sequence, the first regulating current passed through the two groups of radial electromagnets close to or away from the radial X-direction gap sensor probe is restored to the initial value in sequence, so that the rotor moves back and forth along the Y-axis direction on the side close to or away from the radial X-direction gap sensor probe, and the minimum sampling value or the maximum sampling value output by the radial X-direction gap sensor is obtained during the back and forth movement of the rotor.

[0054] Specifically, the steps of obtaining the maximum sampling value output by the radial X-direction gap sensor are as follows: Figure 3 (a) to Figure 3 (d) is shown. First, when no current is passed through the radial electromagnets A2 and A3, and the radial electromagnets A1 and A4 are simultaneously passed through the first adjustment current with an initial value of 1.5A, the combined force of the radial electromagnets A1 and A4 attracts the rotor 40 to the positive direction of the X-axis. Theoretically, it can be considered that the sampling value of the radial X-direction gap sensor at this time is the maximum sampling value. However, in practice, due to the existence of assembly errors, there are also differences in the suction force of the radial electromagnets A1 and A4. Various factors cause the rotor to be not necessarily at the farthest position from the radial X-direction gap sensor at this time, that is, the radial X-direction gap sensor may not sample the maximum value at this time. In order to ensure that the radial X-direction gap sensor can sample the maximum value, the current passed through the radial electromagnet A1 is continuously increased from 1.5A to the maximum value of 2.0A, so that the suction force of the radial electromagnet A1 is increased, and the rotor is slightly attracted upward; then, the current of the radial electromagnet A4 is also increased from 1.5A to 2.0A, so that the rotor returns to the middle position; finally, the current of the radial electromagnet A1 is reduced from 2.0A to 1.5A, so that the rotor is slightly attracted downward. Through Figure 3 (a) to Figure 3 The above steps shown in (d) make the rotor move back and forth near the position farthest from the radial X-direction gap sensor, ensuring that the rotor must pass the position farthest from the radial X-direction gap sensor during this process, so the radial X-direction gap sensor can definitely sample the maximum value. The minimum sampling value output by the remaining radial X-direction gap sensor and the maximum / minimum sampling value output by the radial Y-direction gap sensor are all obtained in this way.

[0055] In one embodiment, the radial electromagnet on the radial bearing is controlled to output according to the preset second regulating current, so as to attract the rotor to a side close to or away from the radial Y-direction gap sensor probe to move back and forth, and the minimum sampling value or the maximum sampling value of the radial Y-direction gap sensor output is obtained during the back and forth movement of the rotor, including:

[0056] Synchronously passing the initial value of the second regulating current into two groups of radial electromagnets close to or away from the radial Y-direction gap sensor probe, thereby attracting the rotor to the side close to or away from the radial Y-direction gap sensor probe;

[0057] After the second regulating current passed through the two groups of radial electromagnets close to or away from the radial Y-direction gap sensor probe is increased to the maximum value in turn, the second regulating current passed through the two groups of radial electromagnets close to or away from the radial Y-direction gap sensor probe is restored to the initial value in turn, so that the rotor moves back and forth along the X-axis direction on the side close to or away from the radial Y-direction gap sensor probe, and the minimum sampling value or the maximum sampling value output by the radial Y-direction gap sensor is obtained during the back-and-forth movement of the rotor.

[0058] In one of the embodiments, a group of axial electromagnets and an axial Z-direction gap sensor probe are disposed on the axial bearing of the active magnetic bearing, and the axial Z-direction gap sensor probe is arranged opposite to the axial electromagnet.

[0059] In one embodiment, the axial electromagnet on the axial bearing in the active magnetic bearing is controlled to output according to a preset third regulating current, so as to attract the rotor to a side close to or away from the axial gap sensor, and obtain the minimum sampling value or the maximum sampling value output by the axial gap sensor, including:

[0060] The axial electromagnet on the axial bearing in the active magnetic bearing is controlled to output according to a preset third regulating current, and when the axial electromagnet has no output and the rotor is attracted to a side close to the axial Z-direction gap sensor probe, a minimum sampling value of the axial Z-direction gap sensor output is obtained;

[0061] When the axial electromagnet outputs a large amount and the rotor is attracted to a side away from the axial Z-direction gap sensor probe, the maximum sampling value of the axial Z-direction gap sensor output is obtained.

[0062] It can be understood that since there is only one set of axial electromagnets, the minimum sampling value of the axial Z-direction gap sensor output is collected when the axial electromagnet has no output and the rotor falls, and the maximum sampling value of the axial Z-direction gap sensor output is collected when the axial electromagnet has a large output and the rotor is sucked to the top.

[0063] In one embodiment, if Figure 4As shown, according to the minimum sampling value, the maximum sampling value and the corresponding actual gap value, the least square method is used for linear fitting to obtain the linear relationship between the radial or axial gap sensor sampling value and the actual gap value, and the online automatic calibration of the radial or axial gap sensor of the active magnetic bearing is completed, including:

[0064] First, according to the minimum sampling value and maximum sampling value output by the radial X-direction gap sensor multiple times and the corresponding actual gap value, the least square method is used for linear fitting to obtain the linear relationship between the radial X-direction gap sensor sampling value and the actual gap value, and the online automatic calibration of the radial X-direction gap sensor is completed. Specifically, after repeating the sampling n times, the minimum sampling value group Xmin1, Xmin2, ..., Xmin n and the maximum sampling value group Xmax1, Xmax2, ..., Xmax n It is known that the minimum sampling value corresponds to the actual gap X1, and the maximum sampling value corresponds to the actual gap X2. The least squares method is used to fit the actual gap X and the radial X-direction gap sensor sampling value X AD The linear relationship between AD =K x *X+B x The coefficient K in x and B x , complete the online automatic calibration of the radial X-direction gap sensor. Among them, the linear relationship between the radial X-direction gap sensor sampling value and the actual gap value obtained by least squares fitting is as follows: Figure 5 As shown, Figure 5 The horizontal axis is the actual gap (unit: mm), and the vertical axis is the radial X-direction gap sensor sampling value (no unit). The actual gap corresponding to a set of minimum sampling values ​​is -0.2 mm, and the actual gap corresponding to a set of maximum sampling values ​​is 0.2 mm. The fitted straight line represents the actual gap X and the radial X-direction gap sensor sampling value X AD The linear relationship between them.

[0065] Then, according to the minimum sampling value and the maximum sampling value output by the radial Y-direction gap sensor multiple times and the corresponding actual gap value, the least squares method is used for linear fitting to obtain the linear relationship between the radial Y-direction gap sensor sampling value and the actual gap value, thereby completing the online automatic calibration of the radial Y-direction gap sensor.

[0066] Finally, according to the minimum sampling value and maximum sampling value output by the axial Z-direction gap sensor multiple times and the corresponding actual gap value, the least squares method is used for linear fitting to obtain the linear relationship between the axial Z-direction gap sensor sampling value and the actual gap value, thus completing the online automatic calibration of the axial Z-direction gap sensor.

[0067] In one embodiment, the radial electromagnet and the axial electromagnet are each composed of two coils.

[0068] It should be understood that although Figure 1 and Figure 4 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, Figure 1 and Figure 4 At least part of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least part of the sub-steps or stages of other steps.

[0069] In one embodiment, an online automatic calibration device for an active magnetic bearing gap sensor is provided, comprising:

[0070] A radial gap sensor sampling module is used for an active magnetic bearing in which gap sensors and electromagnets are alternately arranged, and controls the radial electromagnets on the radial bearings in the active magnetic bearings to output according to a preset first regulating current and a second regulating current, so as to attract the rotor to a side close to or away from the radial gap sensor to move back and forth, and obtain the minimum sampling value or the maximum sampling value output by the radial gap sensor during the back and forth movement of the rotor;

[0071] An axial clearance sensor sampling module is used to control the axial electromagnet on the axial bearing in the active magnetic bearing to output according to a preset third regulating current, so as to attract the rotor to a side close to or away from the axial clearance sensor, and obtain a minimum sampling value or a maximum sampling value output by the axial clearance sensor;

[0072] The online automatic calibration module is used to perform linear fitting using the least squares method according to the minimum sampling value, the maximum sampling value and the corresponding actual gap value, to obtain the linear relationship between the radial or axial gap sensor sampling value and the actual gap value, and complete the online automatic calibration of the radial or axial gap sensor of the active magnetic bearing.

[0073] For the specific definition of the online automatic calibration device for the active magnetic bearing gap sensor, please refer to the definition of the online automatic calibration method for the active magnetic bearing gap sensor above, which will not be repeated here. Each module in the above-mentioned online automatic calibration device for the active magnetic bearing gap sensor can be implemented in whole or in part through software, hardware and a combination thereof. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules.

[0074] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0075] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. An online automatic calibration method for an active magnetic bearing gap sensor, characterized in that: The method comprises: For an active magnetic bearing in which gap sensors and electromagnets are alternately arranged, the radial electromagnets on the radial bearings in the active magnetic bearings are controlled to output according to a preset first regulating current and a second regulating current, so that the rotor is attracted to a side close to or away from the radial gap sensor to move back and forth, and the minimum sampling value or the maximum sampling value output by the radial gap sensor is obtained during the back and forth movement of the rotor; According to a preset third regulating current, the axial electromagnet on the axial bearing in the active magnetic bearing is controlled to output, so as to attract the rotor to a side close to or away from the axial gap sensor, and obtain a minimum sampling value or a maximum sampling value output by the axial gap sensor; According to the minimum sampling value, the maximum sampling value and the corresponding actual gap value, the least squares method is used for linear fitting to obtain the linear relationship between the radial or axial gap sensor sampling value and the actual gap value, thereby completing the online automatic calibration of the radial or axial gap sensor of the active magnetic bearing.

2. The method according to claim 1, characterized in that The radial bearing of the active magnetic bearing is provided with four groups of symmetrically arranged radial electromagnets, a radial X-direction gap sensor probe and a radial Y-direction gap sensor probe, and the two gap sensor probes are staggered at 90 degrees between the radial electromagnets.

3. The method according to claim 2, characterized in that According to the preset first regulating current and second regulating current, the radial electromagnet on the radial bearing in the active magnetic bearing is controlled to output, the rotor is attracted to a side close to or away from the radial gap sensor to move back and forth, and the minimum sampling value or the maximum sampling value output by the radial gap sensor is obtained during the back and forth movement of the rotor, including: According to a preset first regulating current, the radial electromagnet on the radial bearing is controlled to output, so as to attract the rotor to a side close to or away from the radial X-direction gap sensor probe to move back and forth, and the minimum sampling value or the maximum sampling value of the radial X-direction gap sensor output is obtained during the back and forth movement of the rotor; The radial electromagnet on the radial bearing is controlled to output according to the preset second regulating current, so as to attract the rotor to move back and forth close to or away from the side of the radial Y-direction gap sensor probe, and obtain the minimum sampling value or the maximum sampling value of the radial Y-direction gap sensor output during the back and forth movement of the rotor.

4. The method according to claim 3, characterized in that According to the preset first regulating current, the radial electromagnet on the radial bearing is controlled to output, the rotor is attracted to a side close to or away from the radial X-direction gap sensor probe to move back and forth, and the minimum sampling value or the maximum sampling value of the radial X-direction gap sensor output is obtained during the back and forth movement of the rotor, including: Synchronously passing the initial value of the first regulating current into two groups of radial electromagnets close to or far away from the radial X-direction gap sensor probe, thereby attracting the rotor to a side close to or far away from the radial X-direction gap sensor probe; After the first regulating current passed through the two groups of radial electromagnets close to or away from the radial X-direction gap sensor probe is increased to the maximum value in sequence, the first regulating current passed through the two groups of radial electromagnets close to or away from the radial X-direction gap sensor probe is restored to the initial value in sequence, so that the rotor moves back and forth along the Y-axis direction on the side close to or away from the radial X-direction gap sensor probe, and the minimum sampling value or the maximum sampling value output by the radial X-direction gap sensor is obtained during the back-and-forth movement of the rotor.

5. The method according to claim 3, characterized in that: According to the preset second regulating current, the radial electromagnet on the radial bearing is controlled to output, the rotor is attracted to a side close to or away from the radial Y-direction gap sensor probe to move back and forth, and the minimum sampling value or the maximum sampling value of the radial Y-direction gap sensor output is obtained during the back and forth movement of the rotor, including: Synchronously passing the initial value of the second regulating current into two groups of radial electromagnets close to or far away from the radial Y-direction gap sensor probe, thereby attracting the rotor to the side close to or far away from the radial Y-direction gap sensor probe; After the second regulating current passed through the two groups of radial electromagnets close to or away from the radial Y-direction gap sensor probe is increased to the maximum value in turn, the second regulating current passed through the two groups of radial electromagnets close to or away from the radial Y-direction gap sensor probe is restored to the initial value in turn, so that the rotor moves back and forth along the X-axis direction on the side close to or away from the radial Y-direction gap sensor probe, and the minimum sampling value or the maximum sampling value output by the radial Y-direction gap sensor is obtained during the back-and-forth movement of the rotor.

6. The method according to claim 1, characterized in that A group of axial electromagnets and an axial Z-direction gap sensor probe are arranged on the axial bearing of the active magnetic bearing, and the axial Z-direction gap sensor probe is arranged opposite to the axial electromagnet.

7. The method according to claim 6, characterized in that According to a preset third regulating current, the axial electromagnet on the axial bearing in the active magnetic bearing is controlled to output, the rotor is attracted to a side close to or away from the axial gap sensor, and the minimum sampling value or the maximum sampling value output by the axial gap sensor is obtained, including: The axial electromagnet on the axial bearing in the active magnetic bearing is controlled to output according to a preset third regulating current, and when the axial electromagnet has no output and the rotor is attracted to a side close to the axial Z-direction gap sensor probe, a minimum sampling value of the axial Z-direction gap sensor output is obtained; When the axial electromagnet has a large output and the rotor is attracted to a side away from the axial Z-direction gap sensor probe, a maximum sampling value of the axial Z-direction gap sensor output is obtained.

8. The method according to claim 1, wherein the linear relationship between the radial or axial clearance sensor sampling value and the actual clearance value is obtained by using the least squares method for linear fitting according to the minimum sampling value, the maximum sampling value and the corresponding actual clearance value, and the online automatic calibration of the radial or axial clearance sensor of the active magnetic bearing is completed, comprising: According to the minimum sampling value and the maximum sampling value outputted by the radial X-direction gap sensor multiple times and the corresponding actual gap value, the least square method is used for linear fitting to obtain the linear relationship between the radial X-direction gap sensor sampling value and the actual gap value, thereby completing the online automatic calibration of the radial X-direction gap sensor; According to the minimum sampling value and the maximum sampling value outputted by the radial Y-direction gap sensor multiple times and the corresponding actual gap value, the least square method is used for linear fitting to obtain the linear relationship between the radial Y-direction gap sensor sampling value and the actual gap value, thereby completing the online automatic calibration of the radial Y-direction gap sensor; According to the minimum sampling value and the maximum sampling value output by the axial Z-direction gap sensor multiple times and the corresponding actual gap value, the least squares method is used for linear fitting to obtain the linear relationship between the axial Z-direction gap sensor sampling value and the actual gap value, thereby completing the online automatic calibration of the axial Z-direction gap sensor.

9. The method according to claim 1, characterized in that: The radial electromagnet and the axial electromagnet are both composed of two coils.

10. An online automatic calibration device for an active magnetic bearing gap sensor, characterized in that: The device comprises: A radial gap sensor sampling module is used for an active magnetic bearing in which gap sensors and electromagnets are alternately arranged, controlling the radial electromagnets on the radial bearings in the active magnetic bearings to output according to a preset first regulating current and a second regulating current, so as to attract the rotor to a side close to or away from the radial gap sensor to move back and forth, and obtaining a minimum sampling value or a maximum sampling value output by the radial gap sensor during the back and forth movement of the rotor; An axial clearance sensor sampling module is used to control the axial electromagnet on the axial bearing in the active magnetic bearing to output according to a preset third regulating current, so as to attract the rotor to a side close to or away from the axial clearance sensor, and obtain a minimum sampling value or a maximum sampling value output by the axial clearance sensor; The online automatic calibration module is used to perform linear fitting using the least squares method according to the minimum sampling value, the maximum sampling value and the corresponding actual gap value, to obtain the linear relationship between the radial or axial gap sensor sampling value and the actual gap value, and complete the online automatic calibration of the radial or axial gap sensor of the active magnetic bearing.

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