Magnetic levitation system and control method and device, storage medium and program product

Abstract

The application discloses a kind of control method, device, magnetic suspension system of magnetic suspension system, storage medium and computer program product, the method comprises: before magnetic suspension compressor starts, multiple selectors connect dummy load, drive circuit outputs detection current, corresponding voltage signal is collected to carry out static performance detection to current sensor;After passing, multiple selectors are cut to bearing coil, drive circuit outputs detection current, corresponding voltage signal is collected to carry out effectiveness detection to bearing coil;After starting magnetic suspension compressor, rotor position is collected and drive signal is generated, drive circuit outputs current and corresponding voltage signal is collected to carry out dynamic detection to current sensor and bearing coil;Any detection abnormality is closed magnetic suspension compressor.The scheme improves the system interference exclusion ability and full range detection coverage, improves the timeliness of fault identification, and guarantees equipment life.

Description

Technical Field

[0001] This invention belongs to the field of magnetic levitation system control technology, specifically relating to a control method, device, magnetic levitation system, storage medium, and computer program product for a magnetic levitation system. Background Technology

[0002] The magnetic levitation control system is the core component of the magnetic levitation compressor. It outputs control current to maintain the rotor's stable levitation by combining feedback signals from the bearing controller, displacement sensor, and current sensor. Among them, the current sensor needs to accurately feed back the actual current of the bearing coil, which is a key component to ensure control accuracy and avoid rotor shaft wear and collision.

[0003] However, current magnetic levitation systems lack an integrated fault detection mechanism for both the current sensor and the bearing coil. Specifically, before compressor operation, the static performance of the current sensor cannot be tested independently after eliminating coil interference, and the effectiveness of the bearing coil cannot be verified simultaneously. During compressor operation, relying solely on a single current point detection is insufficient to cover the entire operating current range of the sensor / coil. These deficiencies prevent timely identification of faults in the current sensor or bearing coil, directly causing abnormal control current, rotor instability, and ultimately, compressor shaft wear and impact, significantly shortening the equipment's lifespan.

[0004] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Summary of the Invention

[0005] The purpose of this invention is to provide a control method, device, magnetic levitation system, storage medium, and computer program product for a magnetic levitation system. This addresses the problem in related solutions where the magnetic levitation system lacks an integrated fault detection mechanism that can eliminate interference from the bearing coil and cover the entire operating current range. This results in the inability to promptly identify faults in the current sensor or bearing coil, leading to compressor rotor wear and collision, and significantly reducing equipment lifespan. The invention aims to improve interference elimination capabilities and full-range detection coverage, enhance the timeliness of fault identification, and ensure equipment lifespan.

[0006] This invention provides a control method for a magnetic levitation system. The magnetic levitation system includes: a dummy load, a magnetic levitation compressor, a drive circuit, a current sensor, a bearing coil, a displacement sensor, and a multiplexer. The dummy load is used to replace the bearing coil during the detection phase to eliminate interference from the bearing coil on the current sensor detection. The multiplexer is used to switch the connection relationship between the drive circuit, the dummy load, and the bearing coil. The displacement sensor is used to collect the position signal of the magnetic levitation compressor rotor. The method includes: before the magnetic levitation compressor starts, controlling the multiplexer to connect to the dummy load, outputting a first detection current to the dummy load through the drive circuit, collecting a first voltage signal corresponding to the first detection current using the current sensor, and performing static performance testing on the current sensor; if the static performance test of the current sensor is qualified... The system controls the multiplexer to switch to the bearing coil, outputs a second detection current to the bearing coil through the drive circuit, and uses the current sensor to collect the second voltage signal corresponding to the second detection current to perform an effectiveness test on the bearing coil. If the effectiveness test of the bearing coil is qualified, the magnetic levitation compressor is started. During the operation of the magnetic levitation compressor, the displacement sensor collects the real-time position signal of the rotor, generates a drive signal based on the real-time position signal and transmits it to the drive circuit, controls the drive circuit to output current to the bearing coil, and simultaneously uses the current sensor to collect the third voltage signal corresponding to the current to perform dynamic testing on the current sensor and the bearing coil. If any of the static performance test, the effectiveness test, or the dynamic test results are abnormal, the magnetic levitation compressor is shut down.

[0007] In some embodiments, static performance testing of the current sensor includes: comparing the first voltage signal with a preset sensor voltage range; if the first voltage signal is within the preset sensor voltage range, the static performance test of the current sensor is deemed qualified; if the first voltage signal exceeds the preset sensor voltage range, the static performance test of the current sensor is deemed abnormal.

[0008] In some embodiments, the validity test of the bearing coil includes: comparing the second voltage signal with a preset coil voltage range; if the second voltage signal is within the preset coil voltage range, the validity test of the bearing coil is deemed qualified; if the second voltage signal exceeds the preset coil voltage range, the validity test of the bearing coil is deemed abnormal.

[0009] In some implementations, the first detection current includes at least two sets of current values ​​of different magnitudes. When performing static performance testing on the current sensor, the voltage signal corresponding to each set of the first detection current is collected and qualified.

[0010] In some embodiments, the second detection current includes at least two sets of current values ​​of different magnitudes. When performing validity testing on the bearing coil, the voltage signal corresponding to each set of the second detection current is collected and qualified. The number of bearing coils is at least two, and the multiplexer can switch to any one of the bearing coils to perform validity testing on each of the bearing coils one by one.

[0011] In some embodiments, dynamic detection of the current sensor and the bearing coil includes: comparing the third voltage signal with a preset dynamic voltage range; if the third voltage signal is within the preset dynamic voltage range, the dynamic detection is deemed qualified; if the third voltage signal exceeds the preset dynamic voltage range, the dynamic detection is deemed abnormal.

[0012] In some embodiments, the method further includes: during the operation of the magnetic levitation compressor, if the dynamic detection result corresponding to the currently connected bearing coil is abnormal, controlling the multiplexer to switch to another bearing coil and re-perform dynamic detection; if the dynamic detection result is normal after switching, the originally connected bearing coil is determined to be abnormal; if the dynamic detection result is still abnormal after switching, the current sensor is determined to be abnormal.

[0013] In conjunction with the above method, another aspect of the present invention provides a control device for a magnetic levitation system, the magnetic levitation system comprising: a dummy load, a magnetic levitation compressor, a drive circuit, a current sensor, a bearing coil, a displacement sensor, and a multiplexer; the dummy load is used to replace the bearing coil during the detection phase to eliminate interference from the bearing coil on the current sensor detection; the multiplexer is used to switch the connection relationship between the drive circuit and the dummy load and the bearing coil; the displacement sensor is used to acquire the position signal of the rotor of the magnetic levitation compressor; the control device comprises: a static performance detection unit configured to, before the magnetic levitation compressor starts, control the multiplexer to connect to the dummy load, output a first detection current to the dummy load through the drive circuit, and acquire a first voltage signal corresponding to the first detection current using the current sensor to perform static performance detection on the current sensor; and an effectiveness detection unit configured to, if the current sensor detects a dummy load, then detects a dummy load. If the static performance test of the sensor is qualified, the multiplexer is controlled to switch to the bearing coil, and a second detection current is output to the bearing coil through the drive circuit. The second voltage signal corresponding to the second detection current is collected by the current sensor to perform an effectiveness test on the bearing coil. The dynamic detection unit is configured to start the magnetic levitation compressor if the effectiveness test of the bearing coil is qualified. During the operation of the magnetic levitation compressor, the real-time position signal of the rotor is collected by the displacement sensor, a drive signal is generated based on the real-time position signal and transmitted to the drive circuit, and the drive circuit is controlled to output current to the bearing coil. At the same time, the third voltage signal corresponding to the current is collected by the current sensor to perform dynamic detection on the current sensor and the bearing coil. The control unit is configured to shut down the magnetic levitation compressor if any of the detection results of the static performance test, the effectiveness test, or the dynamic test is abnormal.

[0014] In some implementations, the static performance detection unit performs static performance detection on the current sensor, including: comparing the first voltage signal with a preset sensor voltage range; if the first voltage signal is within the preset sensor voltage range, the static performance detection of the current sensor is deemed qualified; if the first voltage signal exceeds the preset sensor voltage range, the static performance detection of the current sensor is deemed abnormal.

[0015] In some embodiments, the validity detection unit performs validity detection on the bearing coil, including: comparing the second voltage signal with a preset coil voltage range; if the second voltage signal is within the preset coil voltage range, the validity detection of the bearing coil is determined to be qualified; if the second voltage signal exceeds the preset coil voltage range, the validity detection of the bearing coil is determined to be abnormal.

[0016] In some implementations, the first detection current includes at least two sets of current values ​​of different magnitudes. When performing static performance testing on the current sensor, the voltage signal corresponding to each set of the first detection current is collected and qualified.

[0017] In some embodiments, the second detection current includes at least two sets of current values ​​of different magnitudes. When performing validity testing on the bearing coil, the voltage signal corresponding to each set of the second detection current is collected and qualified. The number of bearing coils is at least two, and the multiplexer can switch to any one of the bearing coils to perform validity testing on each of the bearing coils one by one.

[0018] In some embodiments, the dynamic detection unit performs dynamic detection on the current sensor and the bearing coil, including: comparing the third voltage signal with a preset dynamic voltage range; if the third voltage signal is within the preset dynamic voltage range, the dynamic detection is deemed qualified; if the third voltage signal exceeds the preset dynamic voltage range, the dynamic detection is deemed abnormal.

[0019] In some embodiments, the dynamic detection unit is further configured to: during the operation of the magnetic levitation compressor, if the dynamic detection result corresponding to the currently connected bearing coil is abnormal, control the multiplexer to switch to another bearing coil and re-perform dynamic detection; if the dynamic detection result is normal after switching, the originally connected bearing coil is determined to be abnormal; if the dynamic detection result is still abnormal after switching, the current sensor is determined to be abnormal.

[0020] In conjunction with the above-described device, the present invention further provides a magnetic levitation system, comprising: a control device for the magnetic levitation system described above.

[0021] In conjunction with the above method, the present invention further provides a storage medium comprising a stored program, wherein, when the program is executed, the device on which the storage medium is located controls the execution of the control method for the magnetic levitation system described above.

[0022] In conjunction with the above method, the present invention further provides a computer program product comprising a computer program that, when processed and executed, implements the steps of the control method for the magnetic levitation system described above.

[0023] The present invention uses a dummy load to isolate the coil interference before starting the magnetic levitation compressor, and first measures the static performance of the current sensor; if it passes the test, it switches to measuring the effectiveness of the bearing coil; during operation, it combines the dynamic detection of both rotor position and the current sensor, and shuts down the compressor if either detection is abnormal. This achieves full coverage of operating conditions from before start-up to during operation, enabling timely identification of sensor or coil faults, preventing compressor rotor shaft wear and collision, and significantly extending equipment life.

[0024] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention.

[0025] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0026] Figure 1 This is a flowchart illustrating an embodiment of the control method for the magnetic levitation system of the present invention;

[0027] Figure 2 This is a schematic diagram of the structure of a control device for the magnetic levitation system of the present invention;

[0028] Figure 3 The hardware structure circuit diagram of the magnetic levitation system;

[0029] Figure 4 This is a flowchart illustrating the static performance testing process of a current sensor.

[0030] Figure 5 This is a flowchart illustrating the process of testing the effectiveness of bearing coils.

[0031] Figure 6 This is a flowchart illustrating the dynamic detection process of a current sensor and bearing coil.

[0032] Figure 7 This is a schematic diagram of the control flow of a multiplexer.

[0033] Referring to the accompanying drawings, the reference numerals in the embodiments of the present invention are as follows:

[0034] 101-Static performance testing unit; 102-Effectiveness testing unit; 103-Dynamic testing unit; 104-Control unit. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0036] According to an embodiment of the present invention, a control method for a magnetic levitation system is provided. The magnetic levitation system includes: a dummy load, a magnetic levitation compressor, a drive circuit, a current sensor, a bearing coil, a displacement sensor, and a multiplexer. The dummy load is used to replace the bearing coil during the detection phase to eliminate interference from the bearing coil on the current sensor detection. The multiplexer is used to switch the connection relationship between the drive circuit and the dummy load and the bearing coil. It can selectively connect the output terminal of the drive circuit to the dummy load or the bearing coil according to control commands to achieve switching detection of different detection objects. The displacement sensor is used to collect the position signal of the rotor of the magnetic levitation compressor.

[0037] System structure such as Figure 3 As shown, the system includes a main control chip, a drive circuit, a dummy load, a bearing coil, a current sensor, and a rotor. The dummy load replaces the bearing coil, completely eliminating interference from the bearing coil when detecting a current sensor fault before operation. Initially, when the compressor is turned on, the drive circuit connects to the dummy load via a 3-to-1 multiplexer. At this point, interference from the bearing coil is eliminated, and fault detection is performed solely on the current sensor. When the current sensor detects no abnormality, the main control chip controls the 3-to-1 multiplexer to connect to the bearing coil via the drive circuit, and the compressor is turned on. Now that the current sensor is known to be fault-free, if an abnormal current occurs again, it can be determined that the magnetic bearing coil is faulty.

[0038] like Figure 1 The flowchart of an embodiment of the method of the present invention is shown. The control method of the magnetic levitation system may include steps S110 to S140.

[0039] In step S110, before the magnetic levitation compressor starts, the multiplexer is controlled to connect to the dummy load, and the first detection current is output to the dummy load through the drive circuit. The first voltage signal corresponding to the first detection current is collected by the current sensor, and the static performance of the current sensor is tested.

[0040] The current sensor is a core component in a magnetic levitation system, responsible for feeding back the current signal. A malfunction in the sensor (such as insufficient detection accuracy or output deviation) can lead to abnormal current control in the subsequent bearing coils. However, the bearing coils themselves may be faulty, and directly connecting them in series with the current sensor would fail to identify the source of the fault. Therefore, a dummy load must first be connected via a multiplexer to eliminate interference from the bearing coils, allowing for separate testing of the current sensor's static performance. This ensures the fundamental accuracy of subsequent bearing coil testing. Static performance testing refers to evaluating the current sensor's detection accuracy and output stability in a static state where the magnetic levitation compressor is not running. The core objective is to verify whether the current sensor can accurately feed back the voltage signal corresponding to the input current.

[0041] Specifically, first, a control command is sent to the multiplexer to connect the output of the drive circuit to the dummy load; then, a current output command is sent to the drive circuit, which outputs a first detection current to the dummy load according to the command; subsequently, the current sensor acquires the first voltage signal corresponding to the first detection current in real time; finally, the first voltage signal is compared with a preset sensor voltage range (based on the linear output characteristics of the current sensor, i.e., the output voltage and input current satisfy...). Relationship, For the sensitivity of the current sensor, For input current, The current sensor's static performance is tested by comparing the offset voltage with the current sensor's offset voltage.

[0042] In some embodiments, step S110, performing static performance testing on the current sensor, includes: comparing the first voltage signal with a preset sensor voltage range; if the first voltage signal is within the preset sensor voltage range, then the static performance test of the current sensor is deemed qualified; if the first voltage signal exceeds the preset sensor voltage range, then the static performance test of the current sensor is deemed abnormal.

[0043] The static performance of a current sensor directly determines its ability to accurately feedback current signals. The core of static performance testing is verifying the matching between the input current and the output voltage. Since current sensors have a fixed linear output characteristic, given the magnitude of the first detected current, the corresponding output voltage (first voltage signal) should be within a pre-calculated reasonable range. If the first voltage signal exceeds this range, it indicates a fault in the current sensor itself (such as sensitivity drift or abnormal offset voltage), making it unable to provide an accurate reference for subsequent bearing coil testing. If it is within the range, the static performance of the current sensor can be confirmed as normal.

[0044] Specifically, firstly through The theoretical voltage value corresponding to the first detected current is calculated, and then, combined with the accuracy level of the current sensor, the reasonable error range corresponding to the theoretical voltage value is determined, ultimately forming a preset sensor voltage range. The multiplexer is controlled to connect to a dummy load, and the drive circuit outputs the first detected current to the dummy load. The current sensor collects the first voltage signal corresponding to the first detected current in real time. The first voltage signal is compared with the preset sensor voltage range: if the value of the first voltage signal is between the upper and lower limits of the preset sensor voltage range, the static performance test of the current sensor is deemed qualified; if the value of the first voltage signal exceeds the preset sensor voltage range, the static performance test of the current sensor is deemed abnormal, the magnetic levitation compressor is controlled to shut down, and a current sensor fault alarm signal is issued.

[0045] In some implementations, the first detection current includes at least two sets of current values ​​of different magnitudes. When performing static performance testing on the current sensor, the voltage signal corresponding to each set of the first detection current is collected and qualified.

[0046] The static performance of a current sensor must be demonstrated by the fact that "within its operating current range, the input current and output voltage always maintain a linear relationship." If detection is performed using only a single initial detection current, faults in localized current ranges may be missed (e.g., the sensor outputs normally at 0A, but deviates at 2A due to changes in internal component characteristics). Therefore, setting at least two sets of initial detection currents of different magnitudes can cover a wider current range. By separately evaluating the voltage signal corresponding to each current set, the sensor's output accuracy under different input currents can be comprehensively verified, ensuring that its static performance is free of localized defects.

[0047] Specifically, based on the range, accuracy level, and detection requirements of the current sensor, at least two sets of first detection currents of different magnitudes are set; the multiplexer is controlled to connect to a dummy load, and the drive circuit sequentially outputs each set of first detection currents to the dummy load; for each set of currents, the current sensor collects the corresponding first voltage signal; for the voltage signal corresponding to each set of first detection currents, a pass / fail judgment is performed individually; if all sets are qualified, the static performance test of the current sensor is judged to be qualified as a whole; if any set is abnormal, the static performance test is judged to be abnormal as a whole, and the magnetic levitation compressor is immediately shut down.

[0048] Figure 4 This is a flowchart illustrating the static performance testing process of a current sensor, specifically including steps 1 to 4.

[0049] Step 1: Upon receiving the start-up command, the main control chip controls the drive circuit to connect to the dummy load via a 3-to-1 multiplexer. The main control chip sends drive signal 'a' (the duty cycle required for 0A current). The drive circuit outputs 0A current to the dummy load (different duty cycles will produce different currents). The current sensor collects the current I of the dummy load. a =0A.

[0050] Step 2, determine I a The corresponding voltage V oa Is it equal to the bias voltage V of the current sensor? off If V oa ≠V off If the current sensor is faulty, the device will shut down and report a fault; if V oa =V off Then proceed to step 3.

[0051] Step 3, the main control chip sends drive signals x(1A, -1A, 2A, -2A...1A) _pn -I _pn The duty cycle required for the current, I _pn -I _pn (The current range is the input current of the current sensor), and the drive circuit outputs current I to the dummy load. x =1A, -1A, 2A, -2A...I _pn -I _pn Each 1A corresponds to one detection point. The sensor's output voltage varies under different input currents, as shown in the following formula: .

[0052] Step 4, based on the relational formula Determine if I x Corresponding voltage V ox Equal to the calculated value V of the relational expression x If V ox =V x If the current sensor is normal, the bearing coil fault detection can be performed; if V ox ≠V x If the current sensor is found to be faulty, the device will be shut down and a fault report will be issued.

[0053] In step S120, if the static performance test of the current sensor is qualified, the multiplexer is controlled to switch to the bearing coil, and the second detection current is output to the bearing coil through the drive circuit. The second voltage signal corresponding to the second detection current is collected by the current sensor to perform an effectiveness test on the bearing coil.

[0054] After confirming the current sensor is functioning correctly, it is necessary to further check the effectiveness of the bearing coil. A faulty bearing coil (such as damaged coil windings preventing current flow) will prevent the magnetic levitation compressor rotor from obtaining stable electromagnetic force, leading to shaft wear and collision problems. Using a functioning current sensor as the benchmark allows for accurate determination of whether the fault originates from the bearing coil. Effectiveness testing refers to checking whether the bearing coil can conduct current normally and whether a fault exists in the bearing coil under static conditions when the magnetic levitation compressor is not running. This judgment must be based on the feedback signal from the confirmed functioning current sensor.

[0055] Specifically, when the static performance test result of the current sensor is qualified, a switching command is sent to the multiplexer to switch the output of the drive circuit from the dummy load to the bearing coil; then, a second detection current output command is sent to the drive circuit, and the drive circuit outputs the second detection current to the bearing coil according to the command; the current sensor collects the second voltage signal corresponding to the second detection current; finally, the second voltage signal is compared with the preset coil voltage range (calculated based on the rated impedance of the bearing coil and the second detection current; if the bearing coil is normal, the voltage signal generated when the current passes through should be within this range) to complete the bearing coil validity test.

[0056] In some embodiments, step S120, which involves performing an effectiveness test on the bearing coil, includes: comparing the second voltage signal with a preset coil voltage range; if the second voltage signal is within the preset coil voltage range, the effectiveness test of the bearing coil is deemed qualified; if the second voltage signal exceeds the preset coil voltage range, the effectiveness test of the bearing coil is deemed abnormal.

[0057] The core function of the bearing coil is to generate electromagnetic force by conducting current to maintain rotor levitation. Its effectiveness directly depends on whether it can conduct the preset current normally. Since the static performance of the current sensor has been confirmed to be qualified, the correspondence between the second voltage signal output by the current sensor and the second detection current is accurate. If the bearing coil is normal, the voltage signal generated when conducting the second detection current will match the theoretical calculation value; if the coil malfunctions (such as a short circuit increasing the current, or an open circuit making the current 0), the voltage signal will deviate from the theoretical value.

[0058] Specifically, firstly, based on the confirmed current sensor parameters and the set value of the second detection current, the theoretical voltage value corresponding to the second detection current when the bearing coil is normal is calculated through a linear relationship; secondly, combined with the rated impedance fluctuation range of the bearing coil, the reasonable fluctuation range of the theoretical voltage value is calculated, and finally the preset coil voltage range is determined; the multiplexer is controlled to switch from the dummy load to the bearing coil, and the drive circuit outputs the second detection current to the bearing coil; the current sensor collects the second voltage signal corresponding to the current in real time; the second voltage signal is compared with the preset coil voltage range: if the second voltage signal is within the preset range, the bearing coil validity detection is deemed qualified; if the second voltage signal exceeds the preset range, the bearing coil validity detection is deemed abnormal, the magnetic levitation compressor is controlled to shut down, and a bearing coil fault alarm signal is issued simultaneously.

[0059] In some embodiments, the second detection current includes at least two sets of current values ​​of different magnitudes. When performing validity testing on the bearing coil, the voltage signal corresponding to each set of the second detection current is collected and qualified. The number of bearing coils is at least two, and the multiplexer can switch to any one of the bearing coils to perform validity testing on each of the bearing coils one by one.

[0060] Bearing coils need to conduct current stably under different current conditions to generate appropriate electromagnetic force. A single current test cannot verify the full load capacity of the coil. At the same time, multi-coil designs need to ensure that each coil is normal to avoid rotor force imbalance due to failure of a single coil.

[0061] Specifically, at least two sets of second detection currents are set, and a multiplexer is connected to the first bearing coil. The drive circuit outputs each set of second detection currents sequentially. For each set of currents, the current sensor collects the corresponding voltage signal and compares it with the preset range of that set. If all sets are qualified, the first coil is initially determined to be valid. The multiplexer is then used to switch to the next bearing coil, and the current detection is repeated until all coils have been tested. If all sets of current detections for all coils are qualified, the overall bearing coil validity test is deemed qualified. If any set of current detections for any coil is abnormal, the validity test is deemed abnormal, and the compressor is shut down.

[0062] Figure 5 This is a flowchart illustrating the effectiveness test of a bearing coil, specifically including steps 5 to 8.

[0063] Step 5: The compressor receives the start command, the multiplexer connects to bearing coil 1 (2), the main control chip sends drive signal a (duty cycle required for 0A current), the drive circuit outputs 0A current to bearing coil 1 (2), and the current sensor collects the current I of bearing coil 1 (2). a =0A.

[0064] Step 6, determine I a The corresponding voltage V oa Is it equal to the bias voltage V of the current sensor? off If V oa ≠V off If the bearing coil 1 (2) is abnormal, it will cause the current sensor to sample inaccurately, and the machine will be shut down and a fault will be reported; if V oa =V off Then proceed to step 7.

[0065] Step 7: The main control chip sends drive signals x(1A, -1A, 2A, -2A...1A) _pn -I _pn The required duty cycle of the current), the drive circuit outputs current I to the bearing coil 1 (2). x =1A, -1A, 2A, -2A...I _pn -I _pn .

[0066] Step 8, based on the relation Determine if I x Corresponding voltage V ox Equal to the calculated value V of the relational expression x If V ox =V x If V is normal, then the bearing coil 1 (2) is determined to be normal; if V ox ≠V x If the bearing coil 1 (2) is found to be abnormal, the machine will be shut down and a fault will be reported.

[0067] In step S130, if the bearing coil validity test is qualified, the magnetic levitation compressor is started. During the operation of the magnetic levitation compressor, the real-time position signal of the rotor is collected by the displacement sensor, a drive signal is generated based on the real-time position signal and transmitted to the drive circuit, and the drive circuit is controlled to output current to the bearing coil. At the same time, the third voltage signal corresponding to the current is collected by the current sensor to perform dynamic detection on the current sensor and the bearing coil.

[0068] Static detection before the start of a magnetic suspension compressor can only eliminate initial faults, while during operation, current sensors and bearing coils may develop dynamic faults due to factors such as ambient temperature changes and current fluctuations (for example, the accuracy of the current sensor decreases under high current working conditions, and local damage occurs to the bearing coil during continuous operation). In addition, the rotor position changes in real time along with the operation of the compressor, it is necessary to collect position signals through displacement sensors and generate corresponding drive signals to adjust the current of the bearing coils to maintain the suspension of the rotor. Meanwhile, detection based on the dynamic current can ensure the reliability of the current sensors and bearing coils under actual working conditions. Dynamic detection refers to real-time detection performed on current sensors and bearing coils in combination with real-time changes in rotor position during the operation of a magnetic suspension compressor. Its core is to verify whether the two can work continuously and stably under dynamic working conditions, so as to avoid faults caused by working condition changes.

[0069] Specifically, when the validity detection result of the bearing coil is qualified, a start command is sent to the magnetic suspension compressor, and the compressor starts to operate; during operation, the displacement sensor continuously collects real-time position signals of the rotor and transmits the signals to the control module; the control module calculates the required electromagnetic force according to the real-time position signals, then generates corresponding drive signals and transmits the drive signals to the drive circuit; the drive circuit outputs currents of corresponding magnitudes and directions to the bearing coils according to the drive signals to maintain the stable suspension of the rotor; meanwhile, the current sensor collects the third voltage signal corresponding to the current in real time; finally, the third voltage signal is compared with a preset dynamic voltage range (determined based on the theoretical current corresponding to the drive signal and the linear characteristics of the current sensor), so as to complete the dynamic detection of the current sensor and the bearing coil.

[0070] In some embodiments, in step S130, performing dynamic detection on the current sensor and the bearing coil includes: comparing the third voltage signal with a preset dynamic voltage range, wherein the preset dynamic voltage range is determined based on the drive signal; if the third voltage signal is within the preset dynamic voltage range, determining that the dynamic detection is qualified; if the third voltage signal is outside the preset dynamic voltage range, determining that the dynamic detection is abnormal.

[0071] When the magnetic suspension compressor is in operation, the rotor position changes in real time due to load changes, rotation speed adjustment and other factors, and it is necessary to continuously adjust the current of the bearing coils through drive signals to maintain suspension. At this time, the working states of the current sensor and the bearing coil will be affected by dynamic working conditions (such as temperature rise and electromagnetic interference), and static detection cannot cover such dynamic faults (for example, the coil impedance drifts during operation while it is normal in static detection).

[0072] Specifically, during the operation of the magnetic levitation compressor, the displacement sensor continuously collects the real-time position signal of the rotor and generates a drive signal (such as an instruction to adjust the magnitude and direction of the current) based on the position signal. At the same time, it calculates the theoretical current that should be supplied to the bearing coil based on the drive signal. Then, combined with the parameters of the current sensor and the normal impedance fluctuation error of the coil under dynamic operating conditions, it calculates the theoretical voltage value and allowable fluctuation range corresponding to the theoretical current, forming a preset dynamic voltage range that is updated in real time. The drive circuit outputs the corresponding current to the bearing coil according to the drive signal, and the current sensor synchronously collects the third voltage signal corresponding to the current. The third voltage signal is compared with the preset dynamic voltage range generated at the same time: if the third voltage signal is within the preset range, the dynamic detection is deemed qualified, and the current operating state is maintained; if the third voltage signal exceeds the preset range, the dynamic detection is deemed abnormal, and a shutdown command is immediately sent to the magnetic levitation compressor, while triggering a dynamic fault alarm signal.

[0073] In some embodiments, the method further includes: during the operation of the magnetic levitation compressor, if the dynamic detection result corresponding to the currently connected bearing coil is abnormal, controlling the multiplexer to switch to another bearing coil and re-perform dynamic detection; if the dynamic detection result is normal after switching, the originally connected bearing coil is determined to be abnormal; if the dynamic detection result is still abnormal after switching, the current sensor is determined to be abnormal.

[0074] When an abnormality is detected during operation, the fault can only originate from two directions: one is a sudden failure of the currently connected bearing coil under dynamic operating conditions; the other is a dynamic failure of the current sensor during operation. Since the other bearing coil has been verified as qualified before startup, it can be used as a reference component. If the detection is normal after switching, it indicates that the fault lies in the original coil; if it is still abnormal, it indicates that the current sensor used as the detection reference is faulty, thus achieving accurate fault location.

[0075] Specifically, during the operation of the magnetic levitation compressor, if the dynamic detection result corresponding to the currently connected bearing coil is abnormal, the path between the currently connected bearing coil and the drive circuit is disconnected, while the path between the other bearing coil and the drive circuit is connected. Subsequently, the dynamic detection is repeated. If, after re-detection, the new third voltage signal is within the preset dynamic voltage range, the original connected bearing coil is determined to be abnormal, the original coil fault information is recorded, and the normal operation of the other bearing coil is maintained, while an alarm for the original coil fault is issued. If, after re-detection, the new third voltage signal still exceeds the preset dynamic voltage range, the current sensor is determined to be abnormal, and the magnetic levitation compressor is immediately shut down to avoid current control failure due to sensor failure, while an alarm for the current sensor fault is issued.

[0076] In step S140, if any of the results of the static performance test, the validity test, or the dynamic test are abnormal, the magnetic levitation compressor is shut down.

[0077] Specifically, during static performance testing, effectiveness testing, or dynamic testing, if the test result is determined to be abnormal, a shutdown command is sent to the magnetic levitation compressor. After receiving the shutdown command, the magnetic levitation compressor stops running and can trigger an alarm signal as needed.

[0078] This solution combines dummy load interference elimination, multiplexer switching of detection targets, and displacement sensor feedback of rotor position to achieve accurate detection and fault protection for current sensors and bearing coils in the magnetic levitation system under all operating conditions. It not only clearly distinguishes between faults in the current sensor and bearing coil, avoiding ambiguous fault location, but also covers potential faults before equipment startup and during operation. Timely shutdown protection reduces equipment damage, ultimately significantly improving the operational stability and reliability of the magnetic levitation compressor, extending equipment lifespan, and providing strong support for the safe and efficient operation of the magnetic levitation system.

[0079] Figure 6 This is a flowchart illustrating the dynamic detection process of the current sensor and bearing coil, specifically including steps 9 to 11.

[0080] Step 9: During compressor operation, the multiplexer connects to bearing coil 1, the displacement sensor detects the rotor position in real time, and outputs a corresponding displacement signal to the main control chip. The main control chip sends a corresponding drive signal x based on the rotor position, and the drive circuit outputs a corresponding current I to bearing coil 1. x The current sensor collects the current I of bearing coil 1. x .

[0081] Step 10, based on the relational formula Determine if I x Corresponding voltage V ox Equal to the calculated value V of the relational expression x If V ox =V x If the current sensor and bearing coil 1 are both normal, then operation can continue; if V ox ≠V x Then proceed to step 11.

[0082] Step 11: Connect the multiplexer to bearing coil 2 and check again whether V... ox =V x If V ox =V x If the bearing coil 1 is found to be abnormal, the compressor will shut down and a fault report for bearing coil 1 will be sent; if V ox ≠V x If the current sensor is faulty, the compressor will shut down and report a current sensor malfunction.

[0083] Figure 7 The control flow diagram for the multiplexer includes steps 12 to 14.

[0084] Step 12: The compressor is turned on. The multiplexer is first connected to a dummy load to perform a static detection operation of the current sensor. At this time, it is determined whether the current sensor is working properly. If not, the compressor is turned off and a current sensor fault is reported; if so, step 13 is executed.

[0085] Step 13: Connect the multi-channel sensor to bearing coil 1 to perform static detection of bearing coil 1. At this time, determine whether bearing coil 1 is working normally. If not, turn off the power and report a fault in bearing coil 1; if yes, proceed to step 14.

[0086] Step 14: Connect the multiplexer to bearing coil 2 and perform a static test on bearing coil 2. At this time, determine whether bearing coil 2 is working properly. If not, shut down the compressor and report a bearing coil 2 fault; if so, the compressor can operate normally.

[0087] The technical solution of this embodiment uses a dummy load to isolate the coil interference before the magnetic levitation compressor starts, and first measures the static performance of the current sensor; if it passes the test, it switches to measure the effectiveness of the bearing coil; during operation, both are dynamically detected by combining the rotor position, and the compressor is shut down if either detection is abnormal. This achieves full coverage of operating conditions from before start-up and shutdown to during operation, and can promptly identify sensor or coil faults, avoiding compressor rotor shaft wear and collision, and significantly extending equipment life.

[0088] According to an embodiment of the present invention, a control device for a magnetic levitation system corresponding to the control method of the magnetic levitation system is also provided. The magnetic levitation system includes: a dummy load, a magnetic levitation compressor, a drive circuit, a current sensor, a bearing coil, a displacement sensor, and a multiplexer; the dummy load is used to replace the bearing coil during the detection phase to eliminate interference from the bearing coil on the current sensor detection; the multiplexer is used to switch the connection relationship between the drive circuit and the dummy load and the bearing coil, and can selectively connect the output terminal of the drive circuit to the dummy load or the bearing coil according to control commands to achieve switching detection of different detection objects; the displacement sensor is used to acquire the position signal of the rotor of the magnetic levitation compressor.

[0089] See Figure 2 The schematic diagram shown is a structural diagram of an embodiment of the device of the present invention. The control device of the magnetic levitation system may include:

[0090] The static performance detection unit 101 is configured to control the multiplexer to connect to the dummy load before the magnetic levitation compressor starts, output a first detection current to the dummy load through the drive circuit, and use the current sensor to collect the first voltage signal corresponding to the first detection current to perform static performance detection on the current sensor. For the specific functions and processing of this unit, please refer to step S110.

[0091] The current sensor is a core component in a magnetic levitation system, responsible for feeding back the current signal. A malfunction in the sensor (such as insufficient detection accuracy or output deviation) can lead to abnormal current control in the subsequent bearing coils. However, the bearing coils themselves may be faulty, and directly connecting them in series with the current sensor would fail to identify the source of the fault. Therefore, a dummy load must first be connected via a multiplexer to eliminate interference from the bearing coils, allowing for separate testing of the current sensor's static performance. This ensures the fundamental accuracy of subsequent bearing coil testing. Static performance testing refers to evaluating the current sensor's detection accuracy and output stability in a static state where the magnetic levitation compressor is not running. The core objective is to verify whether the current sensor can accurately feed back the voltage signal corresponding to the input current.

[0092] Specifically, first, a control command is sent to the multiplexer to connect the output of the drive circuit to the dummy load; then, a current output command is sent to the drive circuit, which outputs a first detection current to the dummy load according to the command; subsequently, the current sensor acquires the first voltage signal corresponding to the first detection current in real time; finally, the first voltage signal is compared with a preset sensor voltage range (based on the linear output characteristics of the current sensor, i.e., the output voltage and input current satisfy...). Relationship, For the sensitivity of the current sensor, For input current, The current sensor's static performance is tested by comparing the offset voltage with the current sensor's offset voltage.

[0093] In some embodiments, the static performance detection unit 101 performs static performance detection on the current sensor, including: comparing the first voltage signal with a preset sensor voltage range; if the first voltage signal is within the preset sensor voltage range, the static performance detection of the current sensor is determined to be qualified; if the first voltage signal exceeds the preset sensor voltage range, the static performance detection of the current sensor is determined to be abnormal.

[0094] The static performance of a current sensor directly determines its ability to accurately feedback current signals. The core of static performance testing is verifying the matching between the input current and the output voltage. Since current sensors have a fixed linear output characteristic, given the magnitude of the first detected current, the corresponding output voltage (first voltage signal) should be within a pre-calculated reasonable range. If the first voltage signal exceeds this range, it indicates a fault in the current sensor itself (such as sensitivity drift or abnormal offset voltage), making it unable to provide an accurate reference for subsequent bearing coil testing. If it is within the range, the static performance of the current sensor can be confirmed as normal.

[0095] Specifically, firstly through The theoretical voltage value corresponding to the first detected current is calculated, and then, combined with the accuracy level of the current sensor, the reasonable error range corresponding to the theoretical voltage value is determined, ultimately forming a preset sensor voltage range. The multiplexer is controlled to connect to a dummy load, and the drive circuit outputs the first detected current to the dummy load. The current sensor collects the first voltage signal corresponding to the first detected current in real time. The first voltage signal is compared with the preset sensor voltage range: if the value of the first voltage signal is between the upper and lower limits of the preset sensor voltage range, the static performance test of the current sensor is deemed qualified; if the value of the first voltage signal exceeds the preset sensor voltage range, the static performance test of the current sensor is deemed abnormal, the magnetic levitation compressor is controlled to shut down, and a current sensor fault alarm signal is issued.

[0096] In some implementations, the first detection current includes at least two sets of current values ​​of different magnitudes. When performing static performance testing on the current sensor, the voltage signal corresponding to each set of the first detection current is collected and qualified.

[0097] The static performance of a current sensor must demonstrate that "within its operating current range, the input current and output voltage always maintain a linear relationship." If detection is performed using only a single initial detection current, faults in localized current ranges may be missed (e.g., the sensor outputs normally at 0A, but deviates at 2A due to changes in internal component characteristics). Therefore, setting at least two sets of initial detection currents of different magnitudes can cover a wider current range. By separately evaluating the voltage signal corresponding to each current set, the sensor's output accuracy under different input currents can be comprehensively verified, ensuring that its static performance is free of localized defects.

[0098] Specifically, based on the current sensor's range, accuracy level, and detection requirements, at least two sets of first detection currents of different magnitudes are set; a multiplexer is controlled to connect to a dummy load, and the drive circuit sequentially outputs each set of first detection currents to the dummy load; for each set of currents, the current sensor collects the corresponding first voltage signal; for each set of voltage signals corresponding to the first detection current, a pass / fail judgment is performed individually; if all sets are qualified, the overall static performance test of the current sensor is deemed qualified; if any set is abnormal, the overall static performance test is deemed abnormal, and the magnetic levitation compressor is immediately shut down.

[0099] The validity detection unit 102 is configured to, if the static performance test of the current sensor is qualified, control the multiplexer to switch to the bearing coil, output a second detection current to the bearing coil through the drive circuit, and use the current sensor to collect the second voltage signal corresponding to the second detection current to perform validity detection on the bearing coil. For the specific functions and processing of this unit, please refer to step S120.

[0100] After confirming the current sensor is functioning correctly, it is necessary to further check the effectiveness of the bearing coil. A faulty bearing coil (such as damaged coil windings preventing current flow) will prevent the magnetic levitation compressor rotor from obtaining stable electromagnetic force, leading to shaft wear and collision problems. Using a functioning current sensor as the benchmark allows for accurate determination of whether the fault originates from the bearing coil. Effectiveness testing refers to checking whether the bearing coil can conduct current normally and whether a fault exists in the bearing coil under static conditions when the magnetic levitation compressor is not running. This judgment must be based on the feedback signal from the confirmed functioning current sensor.

[0101] Specifically, when the static performance test result of the current sensor is qualified, a switching command is sent to the multiplexer to switch the output of the drive circuit from the dummy load to the bearing coil; then, a second detection current output command is sent to the drive circuit, and the drive circuit outputs the second detection current to the bearing coil according to the command; the current sensor collects the second voltage signal corresponding to the second detection current; finally, the second voltage signal is compared with the preset coil voltage range (calculated based on the rated impedance of the bearing coil and the second detection current; if the bearing coil is normal, the voltage signal generated when the current passes through should be within this range) to complete the bearing coil validity test.

[0102] In some embodiments, the validity detection unit 102 performs validity detection on the bearing coil, including: comparing the second voltage signal with a preset coil voltage range; if the second voltage signal is within the preset coil voltage range, the validity detection of the bearing coil is determined to be qualified; if the second voltage signal exceeds the preset coil voltage range, the validity detection of the bearing coil is determined to be abnormal.

[0103] The core function of the bearing coil is to generate electromagnetic force by conducting current to maintain rotor levitation. Its effectiveness directly depends on whether it can conduct the preset current normally. Since the static performance of the current sensor has been confirmed to be qualified, the correspondence between the second voltage signal output by the current sensor and the second detection current is accurate. If the bearing coil is normal, the voltage signal generated when conducting the second detection current will match the theoretical calculation value; if the coil malfunctions (such as a short circuit increasing the current, or an open circuit making the current 0), the voltage signal will deviate from the theoretical value.

[0104] Specifically, firstly, based on the confirmed current sensor parameters and the set value of the second detection current, the theoretical voltage value corresponding to the second detection current when the bearing coil is normal is calculated through a linear relationship; secondly, combined with the rated impedance fluctuation range of the bearing coil, the reasonable fluctuation range of the theoretical voltage value is calculated, and finally the preset coil voltage range is determined; the multiplexer is controlled to switch from the dummy load to the bearing coil, and the drive circuit outputs the second detection current to the bearing coil; the current sensor collects the second voltage signal corresponding to the current in real time; the second voltage signal is compared with the preset coil voltage range: if the second voltage signal is within the preset range, the bearing coil validity detection is deemed qualified; if the second voltage signal exceeds the preset range, the bearing coil validity detection is deemed abnormal, the magnetic levitation compressor is controlled to shut down, and a bearing coil fault alarm signal is issued simultaneously.

[0105] In some embodiments, the second detection current includes at least two sets of current values ​​of different magnitudes. When performing validity testing on the bearing coil, the voltage signal corresponding to each set of the second detection current is collected and qualified. The number of bearing coils is at least two, and the multiplexer can switch to any one of the bearing coils to perform validity testing on each of the bearing coils one by one.

[0106] Bearing coils need to conduct current stably under different current conditions to generate appropriate electromagnetic force. A single current test cannot verify the full load capacity of the coil. At the same time, multi-coil designs need to ensure that each coil is normal to avoid rotor force imbalance due to failure of a single coil.

[0107] Specifically, at least two sets of second detection currents are set, and a multiplexer is connected to the first bearing coil. The drive circuit outputs each set of second detection currents sequentially. For each set of currents, the current sensor collects the corresponding voltage signal and compares it with the preset range of that set. If all sets are qualified, the first coil is initially determined to be valid. The multiplexer is then used to switch to the next bearing coil, and the current detection is repeated until all coils have been tested. If all sets of current detections for all coils are qualified, the overall bearing coil validity test is deemed qualified. If any set of current detections for any coil is abnormal, the validity test is deemed abnormal, and the compressor is shut down.

[0108] The dynamic detection unit 103 is configured to start the magnetic levitation compressor if the bearing coil validity test is qualified; during the operation of the magnetic levitation compressor, it acquires the real-time position signal of the rotor through the displacement sensor, generates a drive signal based on the real-time position signal and transmits it to the drive circuit, controls the drive circuit to output current to the bearing coil, and simultaneously uses the current sensor to acquire the third voltage signal corresponding to the current, performing dynamic detection on the current sensor and the bearing coil. For the specific functions and processing of this unit, please refer to step S130.

[0109] Static testing before starting a magnetic levitation compressor can only rule out initial faults. During operation, however, the current sensor and bearing coil may experience dynamic faults due to factors such as changes in ambient temperature and current fluctuations (e.g., decreased accuracy of the current sensor under high current conditions, or partial damage to the bearing coil during continuous operation). Furthermore, the rotor position changes in real time as the compressor runs. A displacement sensor is needed to collect position signals and generate corresponding drive signals to adjust the bearing coil current to maintain rotor levitation. Monitoring based on this dynamic current is essential to ensure the reliability of both components under actual operating conditions. Dynamic monitoring refers to real-time detection of the current sensor and bearing coil during the operation of the magnetic levitation compressor, taking into account the real-time changes in the rotor position. The core purpose is to verify whether both components can operate stably and continuously under dynamic conditions, preventing faults caused by changes in operating conditions.

[0110] Specifically, when the bearing coil validity test result is qualified, a start command is sent to the magnetic levitation compressor, and the compressor starts running. During operation, the displacement sensor continuously collects the real-time position signal of the rotor and transmits the signal to the control module. The control module calculates the required electromagnetic force based on the real-time position signal, generates the corresponding drive signal, and transmits the drive signal to the drive circuit. The drive circuit outputs a current of corresponding magnitude and direction to the bearing coil according to the drive signal to maintain the rotor's stable levitation. At the same time, the current sensor collects the third voltage signal corresponding to the current in real time. Finally, the third voltage signal is compared with the preset dynamic voltage range (determined based on the theoretical current corresponding to the drive signal and the linear characteristics of the current sensor) to complete the dynamic detection of the current sensor and the bearing coil.

[0111] In some embodiments, the dynamic detection unit 103 performs dynamic detection on the current sensor and the bearing coil, including: comparing the third voltage signal with a preset dynamic voltage range, the preset dynamic voltage range being determined based on the drive signal; if the third voltage signal is within the preset dynamic voltage range, the dynamic detection is deemed qualified; if the third voltage signal exceeds the preset dynamic voltage range, the dynamic detection is deemed abnormal.

[0112] When a magnetic levitation compressor is running, the rotor position changes in real time due to factors such as load changes and speed adjustments. The bearing coil current needs to be continuously adjusted through the drive signal to maintain levitation. At this time, the working state of the current sensor and the bearing coil will be affected by dynamic operating conditions (such as temperature rise and electromagnetic interference). Static detection cannot cover such dynamic faults (such as static normality but coil impedance drift during operation).

[0113] Specifically, during the operation of the magnetic levitation compressor, the displacement sensor continuously collects the real-time position signal of the rotor and generates a drive signal (such as an instruction to adjust the magnitude and direction of the current) based on the position signal. At the same time, it calculates the theoretical current that should be supplied to the bearing coil based on the drive signal. Then, combined with the parameters of the current sensor and the normal impedance fluctuation error of the coil under dynamic operating conditions, it calculates the theoretical voltage value and allowable fluctuation range corresponding to the theoretical current, forming a preset dynamic voltage range that is updated in real time. The drive circuit outputs the corresponding current to the bearing coil according to the drive signal, and the current sensor synchronously collects the third voltage signal corresponding to the current. The third voltage signal is compared with the preset dynamic voltage range generated at the same time: if the third voltage signal is within the preset range, the dynamic detection is deemed qualified, and the current operating state is maintained; if the third voltage signal exceeds the preset range, the dynamic detection is deemed abnormal, and a shutdown command is immediately sent to the magnetic levitation compressor, while triggering a dynamic fault alarm signal.

[0114] In some embodiments, the dynamic detection unit 103 is further configured to: during the operation of the magnetic levitation compressor, if the dynamic detection result corresponding to the currently connected bearing coil is abnormal, control the multiplexer to switch to another bearing coil and re-perform dynamic detection; if the dynamic detection result is normal after switching, it is determined that the originally connected bearing coil is abnormal; if the dynamic detection result is still abnormal after switching, it is determined that the current sensor is abnormal.

[0115] When an abnormality is detected during operation, the fault can only originate from two directions: one is a sudden failure of the currently connected bearing coil under dynamic operating conditions; the other is a dynamic failure of the current sensor during operation. Since the other bearing coil has been verified as qualified before startup, it can be used as a reference component. If the detection is normal after switching, it indicates that the fault lies in the original coil; if it is still abnormal, it indicates that the current sensor used as the detection reference is faulty, thus achieving accurate fault location.

[0116] Specifically, during the operation of the magnetic levitation compressor, if the dynamic detection result corresponding to the currently connected bearing coil is abnormal, the path between the currently connected bearing coil and the drive circuit is disconnected, while the path between the other bearing coil and the drive circuit is connected. Subsequently, the dynamic detection is repeated. If, after re-detection, the new third voltage signal is within the preset dynamic voltage range, the original connected bearing coil is determined to be abnormal, the original coil fault information is recorded, and the normal operation of the other bearing coil is maintained, while an alarm for the original coil fault is issued. If, after re-detection, the new third voltage signal still exceeds the preset dynamic voltage range, the current sensor is determined to be abnormal, and the magnetic levitation compressor is immediately shut down to avoid current control failure due to sensor failure, while an alarm for the current sensor fault is issued.

[0117] The control unit 104 is configured to shut down the magnetic levitation compressor if any of the results of the static performance test, the effectiveness test, or the dynamic test is abnormal. See step S140 for the specific functions and processing of this unit.

[0118] Specifically, during static performance testing, effectiveness testing, or dynamic testing, if the test result is determined to be abnormal, a shutdown command is sent to the magnetic levitation compressor. After receiving the shutdown command, the magnetic levitation compressor stops running and can trigger an alarm signal as needed.

[0119] This solution combines dummy load interference elimination, multiplexer switching of detection targets, and displacement sensor feedback of rotor position to achieve accurate detection and fault protection for current sensors and bearing coils in the magnetic levitation system under all operating conditions. It not only clearly distinguishes between faults in the current sensor and bearing coil, avoiding ambiguous fault location, but also covers potential faults before equipment startup and during operation. Timely shutdown protection reduces equipment damage, ultimately significantly improving the operational stability and reliability of the magnetic levitation compressor, extending equipment lifespan, and providing strong support for the safe and efficient operation of the magnetic levitation system.

[0120] Since the processing and functions implemented by the device in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned methods, any details not covered in the description of this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0121] By employing the technical solution of this invention, a dummy load is used to isolate the coil interference before the magnetic levitation compressor starts, and the static performance of the current sensor is measured first; if it passes the test, the validity of the bearing coil is measured; during operation, both are dynamically detected by combining the rotor position, and the compressor is shut down if either detection is abnormal. This achieves full coverage of operating conditions from before start-up and shutdown to during operation, and can promptly identify sensor or coil faults, avoiding compressor rotor shaft wear and collision, and significantly extending equipment life.

[0122] According to an embodiment of the present invention, a magnetic levitation system corresponding to a control device for a magnetic levitation system is also provided. This magnetic levitation system may include the control device for a magnetic levitation system described above.

[0123] Since the processing and functions implemented by the magnetic levitation system in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned devices, any details not covered in this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0124] By employing the technical solution of this invention, a dummy load is used to isolate the coil interference before the magnetic levitation compressor starts, and the static performance of the current sensor is measured first; if it passes the test, the validity of the bearing coil is measured; during operation, both are dynamically detected by combining the rotor position, and the compressor is shut down if either detection is abnormal. This achieves full coverage of operating conditions from before start-up and shutdown to during operation, and can promptly identify sensor or coil faults, avoiding compressor rotor shaft wear and collision, and significantly extending equipment life.

[0125] According to an embodiment of the present invention, a storage medium corresponding to a control method for a magnetic levitation system is also provided. The storage medium includes a stored program, wherein the program controls the device where the storage medium is located to execute the control method for the magnetic levitation system described above when the program is executed.

[0126] Since the processing and functions implemented by the storage medium in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned methods, any details not covered in this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0127] By employing the technical solution of this invention, a dummy load is used to isolate the coil interference before the magnetic levitation compressor starts, and the static performance of the current sensor is measured first; if it passes the test, the validity of the bearing coil is measured; during operation, both are dynamically detected by combining the rotor position, and the compressor is shut down if either detection is abnormal. This achieves full coverage of operating conditions from before start-up and shutdown to during operation, and can promptly identify sensor or coil faults, avoiding compressor rotor shaft wear and collision, and significantly extending equipment life.

[0128] According to an embodiment of the present invention, a computer program product corresponding to a control method for a magnetic levitation system is also provided. The computer program product includes a computer program that, when processed and executed, implements the steps of the control method for the magnetic levitation system described above.

[0129] Since the processing and functions implemented by the computer program product in this embodiment are basically corresponding to the embodiments, principles and examples of the aforementioned methods, any details not covered in the description of this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0130] By employing the technical solution of this invention, a dummy load is used to isolate the coil interference before the magnetic levitation compressor starts, and the static performance of the current sensor is measured first; if it passes the test, the validity of the bearing coil is measured; during operation, both are dynamically detected by combining the rotor position, and the compressor is shut down if either detection is abnormal. This achieves full coverage of operating conditions from before start-up and shutdown to during operation, and can promptly identify sensor or coil faults, avoiding compressor rotor shaft wear and collision, and significantly extending equipment life.

[0131] In summary, it is readily understood by those skilled in the art that, without conflict, the aforementioned advantageous methods can be freely combined and superimposed.

[0132] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A control method for a magnetic levitation system, characterized in that, The magnetic levitation system includes: a dummy load, a magnetic levitation compressor, a drive circuit, a current sensor, a bearing coil, a displacement sensor, and a multiplexer; the dummy load is used to replace the bearing coil during the detection phase to eliminate interference from the bearing coil on the current sensor detection; the multiplexer is used to switch the connection relationship between the drive circuit, the dummy load, and the bearing coil; the displacement sensor is used to acquire the position signal of the magnetic levitation compressor rotor. The method includes: Before the magnetic levitation compressor is started, the multiplexer is controlled to connect to the dummy load, and the first detection current is output to the dummy load through the drive circuit. The first voltage signal corresponding to the first detection current is collected by the current sensor, and the static performance of the current sensor is tested. If the static performance test of the current sensor is qualified, the multiplexer is controlled to switch to the bearing coil, and the second detection current is output to the bearing coil through the drive circuit. The second voltage signal corresponding to the second detection current is collected by the current sensor to perform an effectiveness test on the bearing coil. If the bearing coil passes the validity test, the magnetic levitation compressor is started. During the operation of the magnetic levitation compressor, the real-time position signal of the rotor is collected by the displacement sensor, a drive signal is generated based on the real-time position signal and transmitted to the drive circuit, and the drive circuit is controlled to output current to the bearing coil. At the same time, the third voltage signal corresponding to the current is collected by the current sensor to perform dynamic detection on the current sensor and the bearing coil. If any of the static performance test, the effectiveness test, or the dynamic test results are abnormal, the magnetic levitation compressor will be shut down.

2. The control method for the magnetic levitation system according to claim 1, characterized in that, Static performance testing of the current sensor includes: The first voltage signal is compared with the preset sensor voltage range; If the first voltage signal is within the preset sensor voltage range, then the static performance test of the current sensor is deemed qualified. If the first voltage signal exceeds the preset sensor voltage range, the static performance of the current sensor is determined to be abnormal.

3. The control method for the magnetic levitation system according to claim 1, characterized in that, The effectiveness of the bearing coil is tested, including: The second voltage signal is compared with a preset coil voltage range; If the second voltage signal is within the preset coil voltage range, then the bearing coil validity test is deemed qualified. If the second voltage signal exceeds the preset coil voltage range, the bearing coil validity detection is determined to be abnormal.

4. The control method for the magnetic levitation system according to claim 1 or 2, characterized in that, The first detection current includes at least two sets of current values ​​of different magnitudes. When performing static performance testing on the current sensor, the voltage signal corresponding to each set of the first detection current is collected and qualified.

5. The control method for the magnetic levitation system according to claim 1 or 3, characterized in that, The second detection current includes at least two sets of current values ​​of different magnitudes. When performing an effectiveness test on the bearing coil, the voltage signal corresponding to each set of the second detection current is collected and a pass / fail judgment is made. The number of bearing coils is at least two, and the multiplexer can switch to any one of the bearing coils to perform validity testing on each of the bearing coils one by one.

6. The control method for the magnetic levitation system according to claim 1, characterized in that, Dynamic detection of the current sensor and the bearing coil includes: The third voltage signal is compared with a preset dynamic voltage range; If the third voltage signal is within the preset dynamic voltage range, the dynamic detection is deemed qualified. If the third voltage signal exceeds the preset dynamic voltage range, then the dynamic detection is determined to be abnormal.

7. The control method for the magnetic levitation system according to claim 5, characterized in that, Also includes: During the operation of the magnetic levitation compressor, if the dynamic detection result corresponding to the currently connected bearing coil is abnormal, the multiplexer is controlled to switch to another bearing coil and perform dynamic detection again. If the dynamic detection result is normal after switching, the bearing coil originally connected is determined to be abnormal. If the dynamic detection result is still abnormal after switching, the current sensor is determined to be abnormal.

8. A control device for a magnetic levitation system, characterized in that, The magnetic levitation system includes: a dummy load, a magnetic levitation compressor, a drive circuit, a current sensor, a bearing coil, a displacement sensor, and a multiplexer; the dummy load is used to replace the bearing coil during the detection phase to eliminate interference from the bearing coil on the current sensor detection; the multiplexer is used to switch the connection relationship between the drive circuit, the dummy load, and the bearing coil; the displacement sensor is used to acquire the position signal of the magnetic levitation compressor rotor. The control device includes: The static performance testing unit is configured to control the multiplexer to connect to the dummy load before the magnetic levitation compressor is started, output a first detection current to the dummy load through the drive circuit, collect a first voltage signal corresponding to the first detection current using the current sensor, and perform static performance testing on the current sensor. The validity detection unit is configured to, if the static performance test of the current sensor is qualified, control the multiplexer to switch to the bearing coil, output a second detection current to the bearing coil through the drive circuit, and use the current sensor to collect the second voltage signal corresponding to the second detection current to perform validity detection on the bearing coil. The dynamic detection unit is configured to start the magnetic levitation compressor if the validity test of the bearing coil is qualified; during the operation of the magnetic levitation compressor, the displacement sensor collects the real-time position signal of the rotor, generates a drive signal based on the real-time position signal and transmits it to the drive circuit, controls the drive circuit to output current to the bearing coil, and at the same time uses the current sensor to collect the third voltage signal corresponding to the current to perform dynamic detection on the current sensor and the bearing coil. The control unit is configured to shut down the magnetic levitation compressor if any of the results of the static performance test, the effectiveness test, or the dynamic test is abnormal.

9. A magnetic levitation system, characterized in that, include: The control device for the magnetic levitation system as described in claim 8.

10. A storage medium, characterized in that, The storage medium includes a stored program, wherein, when the program is executed, the device containing the storage medium is controlled to perform the control method of the magnetic levitation system according to any one of claims 1 to 7.

11. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the control method for the magnetic levitation system as described in any one of claims 1 to 7.

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