Calibration method and device, storage medium, compressor and computer program product

Abstract

The application provides a calibration method, device, storage medium, compressor and computer program product. The method comprises: controlling the operation frequency of a compressor to be sequentially raised to different preset calibration frequencies, and performing calibration of a group of calibration points when the operation frequency is raised to one preset calibration frequency; wherein when calibration of the calibration points at each preset calibration frequency is performed, the parameter value of each calibration parameter of each calibration point is recorded as calibration data of the calibration point, starting from the compressor outlet pressure corresponding to a preset starting calibration point and every preset pressure value being one calibration point; and when the parameter value of each calibration parameter of each calibration point at each preset calibration frequency is recorded, calibration of the compressor performance curve reference point is completed. The scheme provided by the application can reduce the need for manual intervention and improve the accuracy of test data.

Description

Technical Field

[0001] This invention relates to the field of control, and more particularly to a method, apparatus, storage medium, compressor, and computer program product for calibrating a reference point for a compressor performance curve. Background Technology

[0002] Surge is a system-wide instability phenomenon that occurs in centrifugal compressors under low flow and high pressure ratio conditions. When the gas flow rate decreases to a certain critical point (i.e., the surge point), the pressure output by the compressor cannot overcome the resistance of the downstream system, causing the gas to flow in reverse, which in turn triggers periodic airflow oscillations and violent fluctuations, and may ultimately cause equipment damage.

[0003] To effectively avoid surge, it is usually necessary to obtain the compressor's performance curve. In related technologies, the compressor's performance curve is typically obtained by fitting software with laboratory calibration data. Taking a centrifugal air compressor as an example, the specific operating steps are as follows: First, stabilize the air compressor at a specific speed, and then control the flow rate through a regulating valve. Initially, the valve is fully open, the flow rate reaches its maximum value, and data at each measurement point is recorded. Subsequently, the valve is gradually closed to reduce the flow rate, and data recording continues until the air compressor exhibits surge. The flow rate recorded at this point is the minimum flow rate. This process needs to be repeated to obtain operating point data under different speed conditions.

[0004] However, the performance curve testing methods for compressors in related technologies mainly rely on the tester's judgment of abnormal noises during compressor operation. Since different testers have varying sensitivities to sound, this can lead to inconsistencies in calibration data. Summary of the Invention

[0005] The main objective of this invention is to overcome the deficiencies of the aforementioned related technologies and provide a method, apparatus, storage medium, compressor, and computer program product for calibrating a reference point for a compressor performance curve, thereby solving the problem of inconsistent data calibration errors caused by the reliance on the sensory judgment of testers for compressor performance curve calibration in the related technologies.

[0006] This invention provides a method for calibrating reference points for a compressor performance curve, comprising: controlling the compressor's operating frequency to sequentially increase to different preset calibration frequencies, and calibrating a set of calibration points at each preset calibration frequency; wherein, when calibrating calibration points at each preset calibration frequency, starting from the compressor outlet pressure corresponding to a preset initial calibration point, a calibration point is established at each preset pressure value, and the parameter values ​​of each calibration parameter at each calibration point are recorded as calibration data for that calibration point; when the parameter values ​​of each calibration parameter at each calibration point at each preset calibration frequency are recorded, the calibration of the compressor performance curve reference points is completed.

[0007] Optionally, the parameter values ​​of each calibration parameter at each calibration point are recorded as the calibration data for that calibration point, including: controlling the proportional valve to decrease the preset opening value each time, and detecting the compressor outlet pressure. When the compressor outlet pressure reaches the compressor outlet pressure corresponding to the calibration point, the calibration data of the current calibration point is recorded.

[0008] Optionally, the parameter values ​​of each calibration parameter at each calibration point are recorded as the calibration data for that calibration point, including: controlling the opening of the proportional valve to decrease the preset opening value each time starting from 100%, and calibrating each calibration point according to the pressure deviation between the detected compressor outlet pressure and the compressor outlet pressure corresponding to each calibration point.

[0009] Optionally, calibration of each calibration point is performed based on the pressure deviation between the detected compressor outlet pressure and the compressor outlet pressure corresponding to each calibration point. This includes: for the current calibration point, after each time the proportional valve opening is reduced by a preset opening value, determining whether the pressure deviation between the detected current compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is less than a preset pressure deviation threshold; if the pressure deviation between the current compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is less than the preset pressure deviation threshold, then further determining whether the current compressor outlet pressure is within the range where the pressure deviation between the current compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is less than the preset pressure deviation threshold. The compressor outlet pressure with the smallest absolute value is determined. If the current compressor outlet pressure is determined to be the compressor outlet pressure with the smallest absolute value of pressure deviation from the compressor outlet pressure corresponding to the current calibration point, and the pressure deviation from the compressor outlet pressure corresponding to the current calibration point is within the range of less than the preset pressure deviation threshold, then the parameter values ​​of each calibration parameter are recorded as the parameter values ​​of each calibration parameter at the current calibration point. Among them, after each time the opening of the proportional valve is reduced by a preset opening value, it is determined whether surge has occurred. If surge is determined to have occurred, the parameter values ​​of each calibration parameter are recorded as the parameter values ​​of each calibration parameter corresponding to the current calibration point, and the surge critical point parameter is recorded. If surge is determined not to have occurred, the calibration of the next calibration point is continued.

[0010] Optionally, determining whether the current compressor outlet pressure is the compressor outlet pressure with the smallest absolute value of pressure deviation from the compressor outlet pressure corresponding to the current calibration point, within a range where the pressure deviation from the current calibration point is less than a preset pressure deviation threshold, includes: determining whether the absolute value of the pressure deviation between the current compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is less than e. min , where e mine represents the minimum pressure deviation between the current compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point. min The initial value is equal to the maximum outlet pressure of the compressor; when the absolute value of the pressure deviation between the current compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is less than e min At that time, the absolute value of the pressure deviation between the current compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is assigned to emin, which is used as the new emin. min This process continues until the absolute value of the pressure deviation between the compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is not less than e. min At that time, determine the current e min The value is the compressor outlet pressure with the smallest absolute value of the pressure deviation from the compressor outlet pressure corresponding to the current calibration point.

[0011] Optionally, if it is determined that the current compressor outlet pressure is the compressor outlet pressure with the smallest absolute value of pressure deviation from the compressor outlet pressure corresponding to the current calibration point, within a range where the pressure deviation from the current calibration point is less than a preset pressure deviation threshold, then the parameter values ​​of each calibration parameter are recorded as the parameter values ​​of each calibration parameter at the current calibration point. This includes determining whether the absolute value of the pressure deviation between the current compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is less than e. min If so, record the current values ​​of each calibration parameter as intermediate data for the parameter values ​​of each calibration parameter at the current calibration point, continue to control the proportional valve to close, and continue to determine whether the absolute value of the pressure deviation between the current compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is less than e. min If so, record the current parameter values ​​of each calibration parameter, and update the intermediate record data of the parameter values ​​of each calibration parameter at the current calibration point to the current parameter values. Continue in this manner until the absolute value of the pressure deviation between the compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is detected to be not less than e. min Alternatively, the pressure deviation between the compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is greater than the preset pressure deviation threshold.

[0012] Optionally, determining whether surge has occurred includes: determining whether the magnetic bearing displacement change rate, compressor outlet pressure change rate, compressor inlet flow rate change rate, and motor vibration amplitude have all exceeded the corresponding preset maximum values ​​during normal operation for a continuous preset surge judgment time; if the magnetic bearing displacement change rate, compressor outlet pressure change rate, compressor inlet flow rate change rate, and motor vibration amplitude have all exceeded the corresponding maximum values ​​during normal operation for a continuous preset surge judgment time, then surge is determined to have occurred.

[0013] Another aspect of the present invention provides a calibration device for a compressor performance curve reference point, comprising: a calibration unit, configured to control the compressor operating frequency to sequentially increase to different preset calibration frequencies, and to perform calibration of a set of calibration points at each preset calibration frequency; wherein, when calibrating the calibration points at each preset calibration frequency, starting from the compressor outlet pressure corresponding to a preset initial calibration point, a calibration point is established at each preset pressure value, and the parameter values ​​of each calibration parameter at each calibration point are recorded as calibration data for that calibration point; the calibration unit is further configured to: complete the calibration of the compressor performance curve reference point when the parameter values ​​of each calibration parameter at each calibration point at each preset calibration frequency have been recorded.

[0014] Optionally, the calibration unit records the parameter values ​​of each calibration parameter at each calibration point as the calibration data for that calibration point, including: controlling the proportional valve to decrease the preset opening value each time, and detecting the compressor outlet pressure. When the compressor outlet pressure reaches the compressor outlet pressure corresponding to the calibration point, the calibration data of the current calibration point is recorded.

[0015] Optionally, the calibration unit records the parameter values ​​of each calibration parameter at each calibration point as the calibration data for that calibration point, including: controlling the opening of the proportional valve to decrease the preset opening value each time starting from 100%, and calibrating each calibration point according to the pressure deviation between the detected compressor outlet pressure and the compressor outlet pressure corresponding to each calibration point.

[0016] Optionally, the calibration unit calibrates each calibration point based on the detected pressure deviation between the compressor outlet pressure and the compressor outlet pressure corresponding to each calibration point. This includes: for the current calibration point, after each reduction of the proportional valve opening by a preset opening value, determining whether the detected pressure deviation between the current compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is less than a preset pressure deviation threshold; if the pressure deviation between the current compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is less than the preset pressure deviation threshold, further determining whether the current compressor outlet pressure is within the range where the pressure deviation from the compressor outlet pressure corresponding to the current calibration point is less than the preset pressure deviation threshold, and whether the pressure deviation from the compressor outlet pressure corresponding to the current calibration point is within the range where the pressure deviation from the compressor outlet pressure corresponding to the current calibration point is less than the preset pressure deviation threshold. The compressor outlet pressure with the smallest absolute value of pressure deviation; if it is determined that the current compressor outlet pressure is the compressor outlet pressure with the smallest absolute value of pressure deviation from the compressor outlet pressure corresponding to the current calibration point within the range of less than the preset pressure deviation threshold, then the parameter values ​​of each calibration parameter are recorded as the parameter values ​​of each calibration parameter at the current calibration point; wherein, after each time the opening of the proportional valve is reduced by a preset opening value, it is determined whether surge has occurred; if surge has occurred, the parameter values ​​of each calibration parameter are recorded as the parameter values ​​of each calibration parameter corresponding to the current calibration point, and the surge critical point parameter is recorded; if surge has not occurred, the calibration of the next calibration point continues.

[0017] Optionally, the calibration unit determines whether the current compressor outlet pressure is the compressor outlet pressure with the smallest absolute value of the pressure deviation from the compressor outlet pressure corresponding to the current calibration point, within a range where the pressure deviation from the current calibration point is less than a preset pressure deviation threshold. This includes determining whether the absolute value of the pressure deviation between the current compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is less than e. min , where e min e represents the minimum pressure deviation between the current compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point. min The initial value is equal to the maximum outlet pressure of the compressor; when the absolute value of the pressure deviation between the current compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is less than e min At that time, the absolute value of the pressure deviation between the current compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is assigned to emin, which is used as the new emin. min This process continues until the absolute value of the pressure deviation between the compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is not less than e. min At that time, determine the current e minThe value is the compressor outlet pressure with the smallest absolute value of the pressure deviation from the compressor outlet pressure corresponding to the current calibration point.

[0018] Optionally, if the calibration unit determines that the current compressor outlet pressure is the compressor outlet pressure with the smallest absolute value of the pressure deviation from the compressor outlet pressure corresponding to the current calibration point within a range less than a preset pressure deviation threshold, then it records the parameter values ​​of each calibration parameter as the parameter values ​​of each calibration parameter at the current calibration point. This includes determining whether the absolute value of the pressure deviation between the current compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is less than e. min If so, record the current values ​​of each calibration parameter as intermediate data for the parameter values ​​of each calibration parameter at the current calibration point, continue to control the proportional valve to close, and continue to determine whether the absolute value of the pressure deviation between the current compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is less than e. min If so, record the current parameter values ​​of each calibration parameter, and update the intermediate record data of the parameter values ​​of each calibration parameter at the current calibration point to the current parameter values. Continue in this manner until the absolute value of the pressure deviation between the compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is detected to be not less than e. min Alternatively, the pressure deviation between the compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is greater than the preset pressure deviation threshold.

[0019] Optionally, the calibration unit determines whether surge has occurred by: determining whether the magnetic bearing displacement change rate, compressor outlet pressure change rate, compressor inlet flow rate change rate, and motor vibration amplitude all exceed the corresponding preset maximum values ​​during normal operation after a continuous preset surge judgment time; if the magnetic bearing displacement change rate, compressor outlet pressure change rate, compressor inlet flow rate change rate, and motor vibration amplitude all exceed the corresponding maximum values ​​during normal operation after a continuous preset surge judgment time, then surge is determined to have occurred.

[0020] In another aspect, the present invention provides a storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any of the methods described above.

[0021] In another aspect, the present invention provides a compressor including a processor, a memory, and a computer program stored in the memory that can run on the processor, wherein the processor executes the program to implement the steps of any of the methods described above.

[0022] In another aspect, the present invention provides a compressor including any of the calibration devices described above.

[0023] In another aspect, the present invention provides a computer program product, including a computer program that, when executed by a processor, implements the steps of any of the methods described above.

[0024] According to the technical solution of this invention, the reference points for the compressor performance curve can be automatically calibrated, and the calibration points of the entire compressor can be stored. Surge is determined by comprehensively analyzing multiple key parameters, including pressure fluctuations, flow rate changes, vibration signals, and magnetic bearing displacement. After testing, the data can be exported from the host computer and curve fitted, ensuring the integrity and accuracy of the data. This solution significantly reduces the need for manual intervention and improves testing efficiency and data accuracy.

[0025] According to the technical solution of this invention, automatic detection and analysis of surge phenomenon are achieved, completely eliminating the need for traditional manual intervention. This not only significantly improves the consistency and accuracy of calibration data but also effectively protects the hearing health of testing personnel. Furthermore, the automation process greatly simplifies the operation procedures and improves overall testing efficiency. Attached Figure Description

[0026] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0027] Figure 1 This is a schematic diagram of an embodiment of the method for calibrating the reference point of the compressor performance curve provided by the present invention;

[0028] Figure 2 The specific calibration parameters set by the host computer according to a specific embodiment of the present invention are shown;

[0029] Figure 3 The compressor surge detection logic according to the present invention is shown;

[0030] Figure 4 This is a schematic diagram of a specific embodiment of the method for calibrating the reference point of the compressor performance curve provided by the present invention;

[0031] Figure 5 This is a flowchart of a specific embodiment of the method for calibrating the reference point of the compressor performance curve provided by the present invention. Detailed Implementation

[0032] 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.

[0033] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0034] In related technologies, current methods for calibrating the performance curves of magnetic levitation air compressors heavily rely on the sensory judgment of testers. This not only leads to inconsistencies in data calibration errors but may also pose potential risks to the hearing health of testers. For example, the noise generated during testing is significant, and testers often need to remove their noise protection equipment to more clearly capture abnormal breathing sounds. Prolonged exposure to this environment can adversely affect hearing health.

[0035] This invention provides a method for calibrating a reference point for a compressor performance curve. The compressor can specifically be a centrifugal compressor, and more specifically, a magnetically levitated centrifugal air compressor (referred to as a magnetically levitated air compressor).

[0036] Figure 1 This is a schematic diagram of an embodiment of the method for calibrating the reference point of the compressor performance curve provided by the present invention.

[0037] like Figure 1 As shown, according to an embodiment of the present invention, the calibration method includes at least steps S110 and S120.

[0038] Step S110: Control the compressor's operating frequency to increase sequentially to different preset calibration frequencies. Each time the frequency increases to a preset calibration frequency, a set of calibration points are calibrated.

[0039] Preferably, calibration parameters are determined before calibration. For example, calibration parameters are set on the host computer before starting the calibration test. Specific calibration parameters may include: calibration start frequency (calibration start speed) fmin, motor maximum operating frequency (calibration limit speed) fmax, frequency increase step size (frequency difference between two adjacent sets of calibration data) Δf, minimum effective opening degree of the proportional valve Δθ, and proportional valve closing waiting time (maximum response time of the valve mechanism at the minimum opening degree of the proportional valve) Δt. 阀 Parameter point stabilization time (the time it takes for the air compressor outlet pressure to stabilize after the valve stops operating) t 稳 Surge detection time (time for continuous detection of surge conditions) t 喘 The maximum bearing displacement change rate x′ of the magnetic levitation bearing during normal operation max The maximum rate of change of outlet pressure p′ during normal operation max The maximum rate of change of inlet flow during normal operation, Q′ max The maximum rate of change of motor vibration frequency A′ during normal operation fmax The initial calibration pressure (outlet pressure corresponding to the initial calibration point) p for each set of calibration parameters min The parameter point records the pressure step size (the outlet pressure difference (outside the critical point) Δp between two adjacent points of each calibration parameter set) and the allowable deviation (the maximum allowable pressure value for the parameter point during calibration) E. The above calibration parameters can also be referenced. Figure 2 As shown. Figure 2 The specific calibration parameters set by the host computer according to a specific embodiment of the present invention are shown.

[0040] The calibration method of this invention can be executed in the main control unit of the compressor. For example, after the calibration parameters are set, the host computer sends the corresponding modified parameters to the air compressor main control unit, and the main control unit enters the data calibration state.

[0041] Preferably, the air compressor self-test is performed before calibration.

[0042] Specifically, the host computer sends a start command or the start button on the air compressor body is pressed to start the air compressor main control unit and begin executing the automatic calibration program. The air compressor first performs a self-test, which includes the following steps: 1) checking the communication status of each component; 2) turning on the water cooling system; 3) turning on the air cooling system; 4) opening the bypass valve; 5) setting the proportional valve opening to 100%; 6) commanding the bearing controller to levitate the magnetic levitation bearing; 7) if the bearing controller reports that the levitation bearing has been completed and there are no faults in the overall components, the self-test is complete; otherwise, the self-test fails, and the inverter is not allowed to start. After the self-test is completed, calibration is performed.

[0043] During calibration, the operating frequency of the compressor is sequentially increased to different preset calibration frequencies. Each time the frequency is increased to a preset calibration frequency, a set of calibration points are calibrated.

[0044] In other words, the operating frequency of the compressor is controlled to increase. When the operating frequency of the compressor increases to the preset calibration start frequency, a set of calibration points are calibrated. Then, every time the operating frequency of the compressor is controlled to increase to the preset frequency value to reach the next calibration frequency, a set of calibration points is calibrated.

[0045] Specifically, after the self-test is completed, the proportional valve is set to 100% opening, the frequency converter starts, and the motor begins to increase its frequency to the preset calibration frequency f. 标 After that, close the bypass valve and wait for the downstream outlet pressure to stabilize (for example, wait for a certain period of time to determine that the outlet pressure is stable, or continuously detect that the change in outlet pressure is less than a certain pressure value to determine that the outlet pressure is stable) before starting calibration.

[0046] Among them, the preset calibration frequency (preset calibration speed) f 标 =f min +Δf*m, where f is the currently calibrated operating frequency. min The preset calibration starting frequency is defined by Δf, which is the preset frequency value. Δf represents the step size at which the compressor's operating frequency increases sequentially to different preset calibration frequencies. Essentially, it's the preset frequency difference between every two adjacent sets of calibration data. For example, if Δf is 1000 rpm, a set of data is calibrated every 1000 rpm. A smaller Δf results in higher calibration accuracy but also requires more program storage space. m represents the group of calibration data, where m = 0, 1, 2, 3, ... For example, f... min With a speed of 20,000 rpm and Δf of 1,000 rpm, the calibration speed fmin for the 0th calibration data set is 20,000 rpm (m = 0), the calibration speed for the 1st calibration data set is 21,000 rpm (m = 1), and the calibration speed for the 2nd calibration data set is 22,000 rpm (m = 2). During data calibration, a set of data is calibrated at preset frequency increments. After calibrating all data at the current preset calibration frequency (preset calibration speed), m increments by 1. That is, m remains unchanged when calibrating data at the same preset calibration frequency (preset calibration speed). The maximum value of m is equal to the ratio of the difference between the compressor's maximum operating frequency (calibrated limit speed) fmax and the calibration starting frequency (calibrated starting speed) fmin to the preset frequency value Δf, i.e., (fmax / fmin) = fmin / fmin. max -f min ) / Δf.

[0047] When calibrating at each preset calibration frequency, the compressor outlet pressure p corresponding to the preset starting calibration point is... minInitially, a calibration point is established at each preset pressure value Δp. The parameter values ​​of each calibration point are recorded as the calibration data for that point. That is, the compressor outlet pressure corresponding to each calibration point is (p... min +Δp·n), where p min Δp is the compressor outlet pressure corresponding to the preset starting calibration point, which is the preset pressure value. Δp is the compressor outlet pressure difference between every two adjacent calibration points (except for surge limit points). n is the calibration point number, n = 0, 1, 2, 3, ...

[0048] In one specific implementation, the calibration data for each calibration point at each preset calibration frequency can be recorded, for example, as (m, n, a). 参数 b 参数 c 参数 d 参数 (, ...), m represents the group of calibration data, m = 0, 1, 2, 3, ..., each group of calibration data includes calibration data from multiple calibration points, n represents the calibration point number, that is, the nth calibration point of the mth group of calibration data, n = 0, 1, 2, 3, ... Parameters a, b, c, d, ... represent the parameter values ​​of each calibration parameter of the current calibration point of the current group, that is, the parameter values ​​of each calibration parameter of the nth calibration point of the mth group of calibration data.

[0049] Specifically, the proportional valve is controlled to decrease its preset opening value each time, and the compressor outlet pressure is detected. When the compressor outlet pressure reaches the compressor outlet pressure corresponding to the calibration point, the calibration data for the current calibration point is recorded. The preset opening value is equal to the minimum effective opening Δθ of the proportional valve. More specifically, at the current preset calibration frequency (preset calibration speed), the proportional valve opening starts to close from 100%, the compressor outlet pressure slowly rises, and the compressor outlet pressure P is detected. 出口 When the air compressor outlet pressure reaches the preset initial calibration point, the corresponding compressor outlet pressure p min At this time, record the 0th (n=0) data point at the current preset calibration frequency (speed), (1, 0, parameter a at this point, parameter b at this point, ...); continue to decrease the proportional valve opening, and the air compressor discharge pressure continues to rise. When the air compressor discharge pressure reaches p... min When +Δp·n (n=1), record the first (n=1) data point (1, 1, parameter a at this point, parameter b at this point, ...) at the current preset calibration frequency (speed), and so on. min Δp represents the outlet pressure corresponding to the starting calibration point (the 0th calibration point) at the current preset calibration frequency, and Δp represents the compressor outlet pressure difference between every two adjacent calibration points (except for the surge limit point).

[0050] Preferably, since the proportional valve has limited opening adjustment accuracy and may not be able to precisely adjust to the compressor outlet pressure corresponding to the calibration point, when calibrating the calibration point at each preset calibration frequency, the proportional valve opening is controlled to decrease from 100% each time by a preset opening value. The calibration of each calibration point is performed based on the pressure deviation between the detected compressor outlet pressure and the compressor outlet pressure corresponding to each calibration point. The preset opening value is equal to the minimum effective opening Δθ of the proportional valve.

[0051] Specifically, the calibration of each calibration point is performed based on the pressure deviation between the detected compressor outlet pressure and the compressor outlet pressure corresponding to each calibration point. This may include the following steps:

[0052] (1) For the current calibration point, after each time the proportional valve opening is reduced by a preset opening value, the detected current compressor outlet pressure P is determined. 出口 Pressure deviation e from the compressor outlet pressure corresponding to the current calibration point m Is it less than the preset pressure deviation threshold E?

[0053] Among them, e m =P 出口 -(p min +Δp·n); P 出口 p represents the current compressor outlet pressure. min This represents the compressor outlet pressure at the starting calibration point (the 0th calibration point) under the current preset calibration frequency (speed); Δp represents the compressor outlet pressure difference between any two adjacent calibration points (excluding surge limit points); and n represents the calibration point number, i.e., the nth calibration point. The preset pressure deviation threshold E is the maximum allowable deviation pressure value (between the actual calibration point's compressor outlet pressure and the theoretical calibration point's compressor outlet pressure) during the preset calibration. Since the outlet pressure value recorded at each preset parameter calibration point may not be exactly equal to Pmin + Δp·n, due to the limited valve opening adjustment accuracy (e.g., typically only 0.5% or 1%), a certain deviation between the actual and theoretical calibration points is allowed. m Within the deviation range of <E.

[0054] (2) If we determine the current compressor outlet pressure P 出口 Pressure deviation e from the compressor outlet pressure corresponding to the current calibration point m If the pressure deviation is less than the preset pressure deviation threshold E, then it is further determined whether the current compressor outlet pressure is the compressor outlet pressure with the smallest absolute value of the pressure deviation from the compressor outlet pressure corresponding to the current calibration point within the range of less than the preset pressure deviation threshold E.

[0055] (3) If the current compressor outlet pressure is determined to be the compressor outlet pressure with the smallest absolute value of the pressure deviation from the compressor outlet pressure corresponding to the current calibration point within the range of less than the preset pressure deviation threshold E, then record the parameter values ​​of each calibration parameter at the current calibration point.

[0056] Specifically, during calibration at each preset calibration frequency, the proportional valve opening is controlled to decrease from 100% to a preset value each time. The preset opening value decreased each time is equal to the minimum effective opening Δθ of the proportional valve. As the proportional valve opening decreases, the compressor outlet pressure increases. When the compressor outlet pressure increases to the point where the pressure deviation from the compressor outlet pressure corresponding to the current preset parameter calibration point is less than the preset pressure deviation threshold E(e... m If <E), further determine whether the current compressor outlet pressure is e. m The pressure value within the range <E that is closest to the compressor outlet pressure corresponding to the current preset parameter calibration point (i.e., the pressure deviation from the compressor outlet pressure corresponding to the current preset parameter calibration point is the smallest), when the current compressor outlet pressure is e. m When the pressure value within the range <E is closest to the compressor outlet pressure corresponding to the current preset parameter calibration point, record the parameter values ​​of each current calibration parameter as the parameter values ​​of each calibration parameter at the current calibration point.

[0057] In one specific implementation, if the current compressor outlet pressure P is determined... 出口 Pressure deviation e from the compressor outlet pressure corresponding to the current calibration point m If the pressure deviation is less than the preset pressure deviation threshold E, then the current compressor outlet pressure P is further determined. 出口 Pressure deviation e from the compressor outlet pressure corresponding to the current calibration point m absolute value |e m Is it less than e? min ; where e min This represents the minimum pressure deviation between the current compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point. min The initial value is equal to the maximum outlet pressure P of the compressor. max When calibrating at each calibration point, if the pressure deviation between the compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is within a range less than the preset pressure deviation threshold E, then the current compressor outlet pressure P is determined. 出口 Pressure deviation e from the compressor outlet pressure corresponding to the current calibration point m absolute value |e m Is it less than e? minWhen determining the current compressor outlet pressure P 出口 Pressure deviation e from the compressor outlet pressure corresponding to the current calibration point m absolute value |e m |less than e min At that time, record the parameter values ​​of each calibration parameter as intermediate record data of the parameter values ​​of each calibration parameter at the current calibration point, and record the current compressor outlet pressure P. 出口 Pressure deviation e from the compressor outlet pressure corresponding to the current calibration point m absolute value |e m |Assign a value to e min That is, as the new e min Continue to control the proportional valve to close, and monitor the current compressor outlet pressure P. 出口 Determine the current compressor outlet pressure P 出口 Pressure deviation e from the compressor outlet pressure corresponding to the current calibration point m absolute value |e m Is it less than e? min If so, record the current values ​​of each calibration parameter, and update the intermediate records of the parameter values ​​of each calibration parameter at the current calibration point with the recorded values ​​of each calibration parameter. Continue in this manner until the compressor outlet pressure P is detected. 出口 Pressure deviation e from the compressor outlet pressure corresponding to the current calibration point m absolute value |e m |Not less than e min Time (determine the current e) min The value is the compressor outlet pressure with the smallest absolute value of the pressure deviation from the compressor outlet pressure corresponding to the current calibration point. Alternatively, if the pressure deviation between the compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is greater than the preset pressure deviation threshold E, the calibration of the current calibration point is completed, and the calibration of the next calibration point continues. That is to say, at e m <E range e min The intermediate record data of the value and the parameter values ​​of each calibration parameter at the current calibration point will be continuously updated until |e m |Not less than e min At time, or e m When ≥E.

[0058] In one specific implementation, if the current compressor outlet pressure P is determined... 出口 The pressure difference e between the compressor outlet pressure and the current calibration point m absolute value |e m |less than e minThen, the parameter values ​​of each calibration parameter at the current calibration point are recorded as intermediate record data, and the second preset flag bit is set. 中间 Set to 1, i.e., flag 中间 =1, where the second preset flag bit is 1. 中间 A value of 1 indicates that the intermediate recorded data is valid. For example, the parameter values ​​of each current calibration parameter can be copied to (m, n, a). 中间 b 中间 c 中间 d 中间 In the process of setting the second preset flag, ..., the flag will be set to... 中间 Set to 1.

[0059] When starting calibration, the proportional valve opening is 100%, and the compressor outlet pressure P 出口 Approaching atmospheric pressure (atmospheric pressure is the reference zero-point pressure), but less than the outlet pressure value p corresponding to the first calibration point (n=0). min Then e m <0, then e m <E is true, at the start of each calibration point calibration, e min =P max P max If |e is the maximum outlet pressure of the compressor, then m |<e min True. At each preset calibration frequency (speed), at the start of each calibration point, e will be reassigned. min =P max At this time e m =P 出口 -(p min +Δp·n), when calibrating at point 0, and the proportional valve is at 100%, P 出口 =0, at this time |e m The maximum value is |0-(p) min +Δp·0)|,When calibrating the intermediate parameter point, the proportional valve closes slowly, and the compressor outlet pressure rises slowly to reach the next calibration point from the current calibration point. Therefore, the theoretical value is 0<|e m |<Δp, therefore |e m |<e min Both are true.

[0060] When the compressor outlet pressure is lower than the compressor outlet pressure corresponding to the current calibration point (p) min When +Δp·n), e m <0 is true, e m <E is also true, but at this time the compressor outlet pressure increases as the proportional valve opening decreases, e m It keeps decreasing, |em |<e min If true, minimum deviation, intermediate parameter point (m, n, a) 中间 b 中间 c 中间 d 中间 (...) Keep updating, the proportional valve opening continues to decrease until the outlet pressure P... 出口 The pressure is greater than the compressor outlet pressure corresponding to the current calibration point; in this case, 0 < e. m <E, or e m ≥E, when 0<e m When <E, the compressor outlet pressure P 出口 Compressor outlet pressure (p) corresponding to the current calibration point min The absolute value of the pressure deviation of +Δp·n)|e m |Not necessarily less than e min Therefore, the intermediate parameter point may not necessarily be updated. As the opening degree of the proportional valve continues to decrease, e m If the compressor outlet pressure exceeds a certain range from the current calibration point (≥E), it indicates that the current calibration point has been calibrated successfully. This means that data acquisition for the area around calibration point n in the m-group calibration system is complete, and the calibration of the next calibration point can begin. Preferably, when the calibration of the current preset calibration data point is complete, the first preset flag is set to 1 (flag). 参 =1. When the first preset flag is 1, it indicates that the current calibration point has been calibrated.

[0061] Optionally, if no compressor outlet pressure corresponding to the current calibration point is detected within a range of less than the preset pressure deviation threshold E, the parameter values ​​of each calibration parameter are obtained when the compressor outlet pressure closest to the current calibration point is detected, and these values ​​are used as the parameter values ​​of each calibration parameter at the current calibration point.

[0062] Specifically, in abnormal situations where the aforementioned calibration parameters are set incorrectly, resulting in no valid intermediate record data, the parameter values ​​of each calibration parameter recorded in the most recent period are used as the calibration data for the current calibration point, i.e., (m, n, a 参数 b 参数 c 参数 d 参数 ,...).

[0063] (4) When calibrating the current calibration point, after each time the opening of the proportional valve is reduced by a preset opening value, it is determined whether surge has occurred. If surge has occurred, the parameter values ​​of each calibration parameter are recorded as the parameter values ​​of each calibration parameter corresponding to the current calibration point, and the surge critical point parameter is recorded. If surge has not occurred, the calibration of the next calibration point continues.

[0064] For example, it checks whether the first preset flag is 1. If not, it indicates that the calibration of the current calibration point has not been completed, and then it is determined whether surge has occurred. Specifically, the proportional valve is closed, reducing the proportional valve opening (at this time, the compressor outlet pressure increases), and each time the preset opening Δθ (proportional valve opening θ) is closed... 阀 =100% - Δθ·l, where l is the number of times the proportional valve is closed), wait for the first preset delay time Δt. 阀 Wait for the proportional valve mechanism to complete its operation, then wait for the second preset delay time Δt. 稳 Wait for the compressor outlet pressure to stabilize and determine whether surge has occurred. The first preset delay time and / or the second preset delay time can be determined based on the pressure deviation between the current compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point, wherein the larger the pressure deviation, the smaller the first preset delay time and / or the second preset delay time.

[0065] In one specific implementation, determining whether surge has occurred includes: determining whether a preset surge judgment time has been met for a period of time during which the following parameters have been detected: the magnetic levitation bearing displacement change rate x′, the compressor outlet pressure change rate p′, the compressor inlet flow rate change rate Q′, and the motor vibration amplitude (vibration frequency) A. f All exceed the corresponding preset maximum values ​​during normal operation; if the magnetic levitation bearing displacement change rate x′, compressor outlet pressure change rate p′, compressor inlet flow rate change rate Q′, and motor vibration amplitude A are detected for more than the preset surge judgment time, f If all values ​​exceed the corresponding maximum values ​​during normal operation, then surge is determined to have occurred.

[0066] Figure 3 The compressor surge detection logic according to the present invention is shown. Figure 3 As shown, the detection measures include whether the magnetic levitation bearing displacement change rate x′ exceeds the preset maximum bearing displacement change rate x′max, whether the compressor outlet pressure change rate p′ exceeds the preset maximum compressor outlet pressure change rate p′max, whether the compressor inlet flow rate change rate Q′ exceeds the preset maximum inlet flow rate change rate Q′, and the motor vibration amplitude A. f Does it exceed the preset maximum vibration amplitude A? f If all the above conditions are met and the duration is greater than the preset surge judgment time t 喘 If so, then surge is determined to have occurred.

[0067] Furthermore, if surge is detected, the third preset flag is set to 1, i.e., flag. 喘=1, the third preset flag is the surge flag, that is, when the third preset flag is 1, it indicates that surge is about to occur. If surge is determined to occur, the parameter values ​​of each calibration parameter at the current time are recorded as the parameter values ​​of each calibration parameter corresponding to the current calibration point, and the surge critical point parameters (m, 0xFF, A, B, C, D, ...) are recorded. When surge is determined to occur, the parameter values ​​of each calibration parameter at the current time are recorded as the parameter values ​​of each calibration parameter corresponding to the current calibration point, and the calibration of the current preset calibration frequency is stopped, and the calibration of the next preset calibration frequency is performed. That is, the current calibration point is the last calibration point under the current preset calibration frequency (speed).

[0068] Specifically, the bearing displacement change rate x′ can be obtained by real-time bearing displacement detection and calculation using the bearing controller sensor, and then sent to the main control unit; the compressor outlet pressure change rate p′ can be obtained by real-time compressor outlet pressure detection using the pressure sensor; the compressor inlet flow rate change rate Q′ can be calculated by measuring the real-time inlet flow rate using the (nozzle standard tube); and the motor vibration change rate (motor vibration amplitude) A. f This can be detected by setting a magnetoelectric vibration sensor at a specific location on the main motor.

[0069] If we detect the displacement change rate x′ of the magnetic levitation bearing, the compressor outlet pressure change rate p′, the compressor inlet flow rate change rate Q′, and the motor vibration amplitude A... f If any parameter value in θ does not exceed its corresponding maximum value during normal operation, then surge is not considered to occur. If any of the above parameter values ​​does not exceed its corresponding maximum value during normal operation, it indicates that the system is currently in normal operation, and the valve opening θ... 阀 When the pressure is still very high, surge will not occur yet. Continue to update and record the compressor outlet pressure P at this time. 出口 and the parameter values ​​(m, n, a) of each calibration parameter of the system operation 参数 b 参数 c 参数 d 参数 ,...).

[0070] After the current calibration point is calibrated, the next calibration point at the current calibration frequency is calibrated. The initial value of the maximum pressure deviation emin at this point is reassigned to the maximum pressure Pmax, and a new calibration is performed. The valve opening is continued to decrease until the last limit parameter point of this data set is reached. When surge is detected, the parameters stored at the most recently recorded point are the limit parameters and copied to (m, 0xFF, A, B, C, D, ...). At this point, the calibration of the m-th data set is complete. The vent valve is opened, the proportional valve is set to 100% opening, the motor frequency is increased by Δf, and the calibration of the m+1-th data set is performed. The above steps are repeated until all data sets are calibrated.

[0071] Step S120: When the parameter values ​​of each calibration parameter at each calibration point under each preset calibration frequency are recorded, the calibration of the compressor performance curve reference point is completed.

[0072] Specifically, calibration is complete when the parameter values ​​of each calibration point at each preset calibration frequency have been recorded.

[0073] Optionally, the method further includes storing the calibration data of each calibration point at a preset calibration frequency locally and / or sending it to a host computer.

[0074] Specifically, when each calibration point data is stored in the local space of the main control unit, it can be simultaneously sent to the host computer. After calibration is completed, the host computer can also read all the stored calibration data in a unified manner. During the calibration process, the air compressor human-machine interface is calibrating and displays the current calibration progress, such as the values ​​of m and n, and the real-time values ​​of various operating parameters of the air compressor, such as parameter a, parameter b, parameter c, etc.

[0075] To clearly illustrate the technical solution of the present invention, the execution flow of the calibration method for the compressor performance curve reference point provided by the present invention will be described below with several specific embodiments.

[0076] Figure 4 This is a schematic diagram of a specific embodiment of the method for calibrating the reference point of the compressor performance curve provided by the present invention. Figure 4 As shown, calibration begins with the proportional valve opened to 100%, the inverter started at the calibration speed, the proportional valve was slowly closed to allow the outlet pressure to rise slowly, and the outlet pressure and temperature were waited for a delay. The outlet pressure was checked to see if it reached the calibration point range. The data set closest to the calibration point within the calibration point range was selected as the calibration data for the current calibration point. The proportional valve was closed again, and the data for subsequent calibration points were recorded sequentially until surge was detected. After surge was detected, the surge critical point data was recorded, the vent valve was opened, the speed was increased, and calibration for the next speed was performed. It was determined whether this was the last set of data. If so, the calibration was accepted; otherwise, the calibration for the next set of data was performed.

[0077] Figure 5 This is a flowchart of a specific embodiment of the calibration device method for compressor performance curve reference points provided by the present invention. Figure 5 As shown, after the self-test is completed, the proportional valve is set to 100% opening, the frequency converter starts, m=0, and the motor begins to increase its frequency to the rated frequency f. 标 =f min After adding Δf*m, close the vent valve and wait for the downstream outlet pressure to stabilize before calibrating the m-th parameter point and detecting the air compressor outlet pressure P at this time. 出口 And begin calibrating the 0th calibration point of the m-th group. At this time, l = 0, n = 0, flag参 =0, flag 中间 =0,e min =P max First, record the values ​​of each parameter of the air compressor at this time (m, n, a). 参数 b 参数 c 参数 d 参数 (, ...), this is the value recorded in the cycle, which is the pressure difference e between the outlet pressure at this time and the outlet pressure corresponding to the calibration point. m =P 出口 -(p min +Δp·n), initially the proportional valve opening is 100%, the outlet pressure is close to atmospheric pressure, and less than the outlet pressure value p corresponding to the first calibration point (n=0). min Then e m <0, then e m <E is true, at the start of each calibration point calibration, e min =P max P max If |e is the maximum outlet pressure of the compressor, then m |<e min If true, flag 中间 Set the bit to 1, and copy the most recently recorded real-time parameters of each air compressor to (m, n, a). 中间 b 中间 c 中间 d 中间 ...), at this time the flag 参 When the value is 0, the proportional valve is closed. As l++ is executed successively, the opening degree θ of the proportional valve changes. 阀 It will start at 100% and gradually decrease, while the outlet pressure at the downstream end will gradually increase. Each time the proportional valve closes to its minimum opening Δθ, a pressure of Δt is applied. 阀 Delay, wait for the valve mechanism to complete its execution, and then wait for Δt. 稳 After the export pressure stabilizes, test for the presence of Δt. 稳 Within a given time period, the following parameters were measured: the rate of change of the suspension bearing displacement x′, the rate of change of the compressor outlet pressure p′, the rate of change of the compressor inlet flow rate Q′, and the motor vibration amplitude (vibration frequency) A. f If all values ​​exceed the corresponding preset maximum value during normal operation, then it is determined that a surge is about to occur, and the flag is set. 喘 Set to 1; otherwise, it is in normal operating condition, valve opening θ 阀 When the pressure is still very high, surge will not occur, so the outlet pressure and system operating parameters (m, n, a) are continuously updated and recorded. 参数 b 参数 c 参数 d 参数...), the outlet pressure increases as the proportional valve opening decreases, e m It keeps decreasing, |e m |<e min If true, minimum deviation, intermediate parameter point (m, n, a) 中间 b 中间 c 中间 d 中间 (...) Keep updating, the proportional valve continues to reduce its opening until the outlet pressure is greater than the outlet pressure corresponding to the calibration point, at which point 0 < e m <E, or e m ≥E, when 0<e m When <E, the outlet pressure P 出口 With the calibration point (p) min +Δp·n) Absolute value of deviation e m Not necessarily less than e min Therefore, the intermediate parameter point may not necessarily be updated. As the opening degree of the proportional valve continues to decrease, e m If ≥E, it means that data acquisition near calibration point n in the m-group is complete, the flag parameter is set to 1, and the intermediate parameter point record parameter is used as the final stored data for this calibration point (m, n, A, B, C, D, ...). In abnormal cases, if the aforementioned calibration parameter settings are abnormal, resulting in no valid intermediate parameter points, then the most recent period record point is used as the calibration parameter (m, n, a). 参数 b 参数 c 参数 d 参数 After storing the data for one calibration point, calibrate the next calibration point for that group of parameters, increment n, reassign the initial value of the maximum pressure deviation emin to the maximum pressure Pmax, and perform a new calibration. Continue to reduce the valve opening until the final limit parameter point of the last m groups of data is reached. When surge is detected, the parameters stored at the most recent cycle record point are the limit parameters and copied to (m, 0xFF, A, B, C, D, ...). At this point, the calibration of m groups of data is complete. Open the vent valve, set the proportional valve opening to 100%, increase the motor frequency by Δf, increment m, and perform the calibration of the m+1 group of data. Repeat the above steps until all groups of data are calibrated.

[0078] The present invention also provides a calibration device for a compressor performance curve reference point.

[0079] The calibration device for the compressor performance curve reference point includes a calibration unit, which controls the compressor's operating frequency to be increased sequentially to different preset calibration frequencies, and performs calibration of a set of calibration points every time it is increased to a preset calibration frequency.

[0080] Preferably, calibration parameters are determined before calibration. For example, calibration parameters are set on the host computer before starting the calibration test. Specific calibration parameters may include: calibration start frequency (calibration start speed) fmin, motor maximum operating frequency (calibration limit speed) fmax, frequency increase step size (frequency difference between two adjacent sets of calibration data) Δf, minimum effective opening degree of the proportional valve Δθ, and proportional valve closing waiting time (maximum response time of the valve mechanism at the minimum opening degree of the proportional valve) Δt. 阀 Parameter point stabilization time (the time it takes for the air compressor outlet pressure to stabilize after the valve stops operating) t 稳 Surge detection time (time for continuous detection of surge conditions) t 喘 The maximum bearing displacement change rate x′ of the magnetic levitation bearing during normal operation max The maximum rate of change of outlet pressure p′ during normal operation max The maximum rate of change of inlet flow during normal operation, Q′ max The maximum rate of change of motor vibration frequency A′ during normal operation fmax The initial calibration pressure (outlet pressure corresponding to the initial calibration point) p for each set of calibration parameters min The parameter points record the pressure step size (the outlet pressure difference between two adjacent points in each calibration parameter group (outside the critical point) Δp) and the allowable deviation (the maximum allowable pressure deviation of the parameter point during calibration) E. The above calibration parameters can also be referenced. Figure 1 As shown. Figure 1 The specific calibration parameters set by the host computer according to a specific embodiment of the present invention are shown.

[0081] The calibration device of this invention can be executed in the main control unit of the compressor. For example, after the calibration parameters are set, the host computer sends the corresponding modified parameters to the air compressor main control unit, and the main control unit enters the data calibration state.

[0082] Preferably, the air compressor self-test is performed before calibration.

[0083] Specifically, the host computer sends a start command or the start button on the air compressor body is pressed to start the air compressor main control unit and begin executing the automatic calibration program. The air compressor first performs a self-test, which includes the following steps: 1) checking the communication status of each component; 2) turning on the water cooling system; 3) turning on the air cooling system; 4) opening the bypass valve; 5) setting the proportional valve opening to 100%; 6) commanding the bearing controller to levitate the magnetic levitation bearing; 7) if the bearing controller reports that the levitation bearing has been completed and there are no faults in the overall components, the self-test is complete; otherwise, the self-test fails, and the inverter is not allowed to start. After the self-test is completed, calibration is performed.

[0084] During calibration, the operating frequency of the compressor is sequentially increased to different preset calibration frequencies. Each time the frequency is increased to a preset calibration frequency, a set of calibration points are calibrated.

[0085] In other words, the operating frequency of the compressor is controlled to increase. When the operating frequency of the compressor increases to the preset calibration start frequency, a set of calibration points are calibrated. Then, every time the operating frequency of the compressor is controlled to increase to the preset frequency value to reach the next calibration frequency, a set of calibration points is calibrated.

[0086] Specifically, after the self-test is completed, the proportional valve is set to 100% opening, the frequency converter starts, and the motor begins to increase its frequency to the preset calibration frequency f. 标 After that, close the bypass valve and wait for the downstream outlet pressure to stabilize (for example, wait for a certain period of time to determine that the outlet pressure is stable, or continuously detect that the change in outlet pressure is less than a certain pressure value to determine that the outlet pressure is stable) before starting calibration.

[0087] Among them, the preset calibration frequency (preset calibration speed) f 标 =f min +Δf*m, where f is the currently calibrated operating frequency. min The preset calibration starting frequency is defined by Δf, which is the preset frequency value. Δf represents the step size at which the compressor's operating frequency increases sequentially to different preset calibration frequencies. Essentially, it's the preset frequency difference between every two adjacent sets of calibration data. For example, if Δf is 1000 rpm, a set of data is calibrated every 1000 rpm. A smaller Δf results in higher calibration accuracy but also requires more program storage space. m represents the group of calibration data, where m = 0, 1, 2, 3, ... For example, f... min Given a speed of 20,000 rpm and a Δf of 1,000 rpm, the calibration speed f of the 0th calibration data set is... min The calibration speed for the first set of calibration data is 20000 rpm (m=0), 21000 rpm (m=1), and 22000 rpm (m=2) for the second set of calibration data. During data calibration, a set of data is calibrated at preset frequency increments. After calibrating all data at the current preset calibration frequency (preset calibration speed), m increments by 1. That is, m remains unchanged when calibrating data at the same preset calibration frequency (preset calibration speed). The maximum value of m is equal to the ratio of the difference between the compressor's maximum operating frequency (calibrated limit speed) fmax and the calibration starting frequency (calibrated starting speed) fmin to the preset frequency value Δf, i.e., (f... max -f min ) / Δf.

[0088] When calibrating at each preset calibration frequency, the compressor outlet pressure p corresponding to the preset starting calibration point is... minInitially, a calibration point is established at each preset pressure value Δp. The parameter values ​​of each calibration point are recorded as the calibration data for that point. That is, the compressor outlet pressure corresponding to each calibration point is (p... min +Δp·n), where p min Δp is the compressor outlet pressure corresponding to the preset starting calibration point, which is the preset pressure value. Δp is the compressor outlet pressure difference between every two adjacent calibration points (except for surge limit points). n is the calibration point number, n = 0, 1, 2, 3, ...

[0089] In one specific implementation, the calibration data of each calibration point at each preset calibration frequency can be recorded as (m, n, parameter a, parameter b, parameter c, parameter d, ...), where m represents the group of calibration data, m = 0, 1, 2, 3, ..., and each group of calibration data includes calibration data from multiple calibration points. n represents the number of the calibration point, i.e., the nth calibration point of the mth group of calibration data, n = 0, 1, 2, 3, ..., and parameter a, parameter b, parameter c, parameter d, ... represent the parameter values ​​of each calibration parameter of the current calibration point in the current group, i.e., the parameter values ​​of each calibration parameter of the nth calibration point in the mth group of calibration data.

[0090] Specifically, the proportional valve is controlled to decrease its preset opening value each time, and the compressor outlet pressure is detected. When the compressor outlet pressure reaches the compressor outlet pressure corresponding to the calibration point, the calibration data for the current calibration point is recorded. The preset opening value is equal to the minimum effective opening Δθ of the proportional valve. More specifically, at the current preset calibration frequency (preset calibration speed), the proportional valve opening starts to close from 100%, the compressor outlet pressure slowly rises, and the compressor outlet pressure P is detected. 出口 When the air compressor outlet pressure reaches the preset initial calibration point, the corresponding compressor outlet pressure p min At this time, record the 0th (n=0) data point at the current preset calibration frequency (speed), (1, 0, parameter a at this point, parameter b at this point, ...); continue to decrease the proportional valve opening, and the air compressor discharge pressure continues to rise. When the air compressor discharge pressure reaches p... min When +Δp·n (n=1), record the first (n=1) data point (1, 1, parameter a at this point, parameter b at this point, ...) at the current preset calibration frequency (speed), and so on. min Δp represents the outlet pressure corresponding to the starting calibration point (the 0th calibration point) at the current preset calibration frequency, and Δp represents the compressor outlet pressure difference between every two adjacent calibration points (except for the surge limit point).

[0091] Preferably, since the proportional valve has limited opening adjustment accuracy and may not be able to precisely adjust to the compressor outlet pressure corresponding to the calibration point, when calibrating the calibration point at each preset calibration frequency, the proportional valve opening is controlled to decrease from 100% each time by a preset opening value. The calibration of each calibration point is performed based on the pressure deviation between the detected compressor outlet pressure and the compressor outlet pressure corresponding to each calibration point. The preset opening value is equal to the minimum effective opening Δθ of the proportional valve.

[0092] Specifically, the calibration of each calibration point is performed based on the pressure deviation between the detected compressor outlet pressure and the compressor outlet pressure corresponding to each calibration point. This may include the following steps:

[0093] (1) For the current calibration point, after each time the proportional valve opening is reduced by a preset opening value, the detected current compressor outlet pressure P is determined. 出口 Pressure deviation e from the compressor outlet pressure corresponding to the current calibration point m Is it less than the preset pressure deviation threshold E?

[0094] Among them, e m =P 出口 -(p min +Δp·n); P 出口 p represents the current compressor outlet pressure. min This represents the compressor outlet pressure at the starting calibration point (the 0th calibration point) under the current preset calibration frequency (speed); Δp represents the compressor outlet pressure difference between any two adjacent calibration points (excluding surge limit points); and n represents the calibration point number, i.e., the nth calibration point. The preset pressure deviation threshold E is the maximum allowable deviation pressure value (between the actual calibration point's compressor outlet pressure and the theoretical calibration point's compressor outlet pressure) during the preset calibration. Since the outlet pressure value recorded at each preset parameter calibration point may not be exactly equal to Pmin + Δp·n, due to the limited valve opening adjustment accuracy (e.g., typically only 0.5% or 1%), a certain deviation between the actual and theoretical calibration points is allowed. m Within the deviation range of <E.

[0095] (2) If we determine the current compressor outlet pressure P 出口 Pressure deviation e from the compressor outlet pressure corresponding to the current calibration point m If the pressure deviation is less than the preset pressure deviation threshold E, then it is further determined whether the current compressor outlet pressure is the compressor outlet pressure with the smallest absolute value of the pressure deviation from the compressor outlet pressure corresponding to the current calibration point within the range of less than the preset pressure deviation threshold E.

[0096] (3) If the current compressor outlet pressure is determined to be the compressor outlet pressure with the smallest absolute value of the pressure deviation from the compressor outlet pressure corresponding to the current calibration point within the range of less than the preset pressure deviation threshold E, then record the parameter values ​​of each calibration parameter at the current calibration point.

[0097] Specifically, during calibration at each preset calibration frequency, the proportional valve opening is controlled to decrease from 100% to a preset value each time. The preset opening value decreased each time is equal to the minimum effective opening Δθ of the proportional valve. As the proportional valve opening decreases, the compressor outlet pressure increases. When the compressor outlet pressure increases to the point where the pressure deviation from the compressor outlet pressure corresponding to the current preset parameter calibration point is less than the preset pressure deviation threshold E(e... m If <E), further determine whether the current compressor outlet pressure is e. m The pressure value within the range <E that is closest to the compressor outlet pressure corresponding to the current preset parameter calibration point (i.e., the pressure deviation from the compressor outlet pressure corresponding to the current preset parameter calibration point is the smallest), when the current compressor outlet pressure is e. m When the pressure value within the range <E is closest to the compressor outlet pressure corresponding to the current preset parameter calibration point, record the parameter values ​​of each current calibration parameter as the parameter values ​​of each calibration parameter at the current calibration point.

[0098] In one specific implementation, if the current compressor outlet pressure P is determined... 出口 Pressure deviation e from the compressor outlet pressure corresponding to the current calibration point m If the pressure deviation is less than the preset pressure deviation threshold E, then the current compressor outlet pressure P is further determined. 出口 Pressure deviation e from the compressor outlet pressure corresponding to the current calibration point m absolute value |e m Is it less than e? min ; where e min This represents the minimum pressure deviation between the current compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point. min The initial value is equal to the maximum outlet pressure P of the compressor. max When calibrating at each calibration point, if the pressure deviation between the compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is within a range less than the preset pressure deviation threshold E, then the current compressor outlet pressure P is determined. 出口 Pressure deviation e from the compressor outlet pressure corresponding to the current calibration point m absolute value |e m Is it less than e? minWhen determining the current compressor outlet pressure P 出口 Pressure deviation e from the compressor outlet pressure corresponding to the current calibration point m absolute value |e m |less than e min At that time, record the parameter values ​​of each calibration parameter as intermediate record data of the parameter values ​​of each calibration parameter at the current calibration point, and record the current compressor outlet pressure P. 出口 Pressure deviation e from the compressor outlet pressure corresponding to the current calibration point m absolute value |e m |Assign the value to emin, that is, use it as the new e min Continue to control the proportional valve to close, and monitor the current compressor outlet pressure P. 出口 Determine the current compressor outlet pressure P 出口 Pressure deviation e from the compressor outlet pressure corresponding to the current calibration point m absolute value |e m Is it less than e? min If so, record the current values ​​of each calibration parameter, and update the intermediate records of the parameter values ​​of each calibration parameter at the current calibration point with the recorded values ​​of each calibration parameter. Continue in this manner until the compressor outlet pressure P is detected. 出口 Pressure deviation e from the compressor outlet pressure corresponding to the current calibration point m absolute value |e m |Not less than e min Time (determine the current e) min The value is the compressor outlet pressure with the smallest absolute value of the pressure deviation from the compressor outlet pressure corresponding to the current calibration point. Alternatively, if the pressure deviation between the compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is greater than the preset pressure deviation threshold E, the calibration of the current calibration point is completed, and the calibration of the next calibration point continues. That is to say, at e m <E range e min The intermediate record data of the value and the parameter values ​​of each calibration parameter at the current calibration point will be continuously updated until |e m |Not less than e min At time, or e m When ≥E.

[0099] In one specific implementation, if the current compressor outlet pressure P is determined... 出口 The pressure difference e between the compressor outlet pressure and the current calibration point m absolute value |e m |less than e min Then, the parameter values ​​of each calibration parameter at the current calibration point are recorded as intermediate record data, and the second preset flag bit is set.中间 Set to 1, i.e., flag 中间 =1, where the second preset flag bit is 1. 中间 A value of 1 indicates that the intermediate recorded data is valid. For example, the parameter values ​​of each current calibration parameter can be copied to (m, n, a). 中间 b 中间 c 中间 d 中间 In the process of setting the second preset flag, ..., the flag will be set to... 中间 Set to 1.

[0100] When starting calibration, the proportional valve opening is 100%, and the compressor outlet pressure P 出口 Approaching atmospheric pressure (atmospheric pressure is the reference zero-point pressure), but less than the outlet pressure value p corresponding to the first calibration point (n=0). min Then e m <0, then e m <E is true, at the start of each calibration point calibration, e min =P max P max If |e is the maximum outlet pressure of the compressor, then m |<e min True. At each preset calibration frequency (speed), at the start of each calibration point, e will be reassigned. min =P max At this time e m =P 出口 -(p min +Δp·n), when calibrating at point 0, and the proportional valve is at 100%, P 出口 =0, at this time |e m The maximum value is |0-(p) min +Δp·0)|,When calibrating the intermediate parameter point, the proportional valve closes slowly, and the compressor outlet pressure rises slowly to reach the next calibration point from the current calibration point. Therefore, the theoretical value is 0<|e m |<Δp, therefore |e m |<e min Both are true.

[0101] When the compressor outlet pressure is lower than the compressor outlet pressure corresponding to the current calibration point (p) min When +Δp·n), e m <0 is true, e m <E is also true, but at this time the compressor outlet pressure increases as the proportional valve opening decreases, e m It keeps decreasing, |e m |<e min If true, minimum deviation, intermediate parameter point (m, n, a) 中间 b中间 c 中间 d 中间 (...) Keep updating, the proportional valve opening continues to decrease until the outlet pressure P... 出口 The pressure is greater than the compressor outlet pressure corresponding to the current calibration point; in this case, 0 < e. m <E, or e m >E, when 0<e m When <E, the compressor outlet pressure P 出口 Compressor outlet pressure (p) corresponding to the current calibration point min The absolute value of the pressure deviation of +Δp·n)|e m |Not necessarily less than e min Therefore, the intermediate parameter point may not necessarily be updated. As the opening degree of the proportional valve continues to decrease, e m If the compressor outlet pressure exceeds a certain range from the current calibration point (≥E), it indicates that the current calibration point has been calibrated successfully. This means that data acquisition for the area around calibration point n in the m-group calibration system is complete, and the calibration of the next calibration point can begin. Preferably, when the calibration of the current preset calibration data point is complete, the first preset flag is set to 1 (flag). 参 =1. When the first preset flag is 1, it indicates that the current calibration point has been calibrated.

[0102] Optionally, if no compressor outlet pressure corresponding to the current calibration point is detected within a range of less than the preset pressure deviation threshold E, the parameter values ​​of each calibration parameter are obtained when the compressor outlet pressure closest to the current calibration point is detected, and these values ​​are used as the parameter values ​​of each calibration parameter at the current calibration point.

[0103] Specifically, in abnormal situations where the aforementioned calibration parameters are set incorrectly, resulting in no valid intermediate record data, the parameter values ​​of each calibration parameter recorded in the most recent period are used as the calibration data for the current calibration point, i.e., (m, n, a 参数 b 参数 c 参数 d 参数 ,...).

[0104] (4) When calibrating the current calibration point, after each time the opening of the proportional valve is reduced by a preset opening value, it is determined whether surge has occurred. If surge has occurred, the parameter values ​​of each calibration parameter are recorded as the parameter values ​​of each calibration parameter corresponding to the current calibration point, and the surge critical point parameter is recorded. If surge has not occurred, the calibration of the next calibration point continues.

[0105] For example, it checks whether the first preset flag is 1. If not, it indicates that the calibration of the current calibration point has not been completed, and then it is determined whether surge has occurred. Specifically, the proportional valve is closed, reducing the proportional valve opening (at this time, the compressor outlet pressure increases), and each time the preset opening Δθ (proportional valve opening θ) is closed... 阀 =100% - Δθ·l, where l is the number of times the proportional valve is closed), wait for the first preset delay time Δt. 阀 Wait for the proportional valve mechanism to complete its operation, then wait for the second preset delay time Δt. 稳 Wait for the compressor outlet pressure to stabilize and determine whether surge has occurred. The first preset delay time and / or the second preset delay time can be determined based on the pressure deviation between the current compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point, wherein the larger the pressure deviation, the smaller the first preset delay time and / or the second preset delay time.

[0106] In one specific implementation, determining whether surge has occurred includes: determining whether a preset surge judgment time has been met for a period of time during which the following parameters have been detected: the magnetic levitation bearing displacement change rate x′, the compressor outlet pressure change rate p′, the compressor inlet flow rate change rate Q′, and the motor vibration amplitude (vibration frequency) A. f All exceed the corresponding preset maximum values ​​during normal operation; if the magnetic levitation bearing displacement change rate x′, compressor outlet pressure change rate p′, compressor inlet flow rate change rate Q′, and motor vibration amplitude A are detected for more than the preset surge judgment time, f If all values ​​exceed the corresponding maximum values ​​during normal operation, then surge is determined to have occurred.

[0107] Figure 4 The compressor surge detection logic according to the present invention is shown. Figure 4 As shown, the detection measures include whether the magnetic levitation bearing displacement change rate x′ exceeds the preset maximum bearing displacement change rate x′max, whether the compressor outlet pressure change rate p′ exceeds the preset maximum compressor outlet pressure change rate p′max, whether the compressor inlet flow rate change rate Q′ exceeds the preset maximum inlet flow rate change rate Q′, and the motor vibration amplitude A. f Does it exceed the preset maximum vibration amplitude A? f If all the above conditions are met and the duration is greater than the preset surge judgment time t 喘 If so, then surge is determined to have occurred.

[0108] Furthermore, if surge is detected, the third preset flag is set to 1, i.e., flag. 喘=1, the third preset flag is the surge flag, that is, when the third preset flag is 1, it indicates that surge is about to occur. If surge is determined to occur, the parameter values ​​of each calibration parameter at the current time are recorded as the parameter values ​​of each calibration parameter corresponding to the current calibration point, and the surge critical point parameters (m, 0xFF, A, B, C, D, ...) are recorded. When surge is determined to occur, the parameter values ​​of each calibration parameter at the current time are recorded as the parameter values ​​of each calibration parameter corresponding to the current calibration point, and the calibration of the current preset calibration frequency is stopped, and the calibration of the next preset calibration frequency is performed. That is, the current calibration point is the last calibration point under the current preset calibration frequency (speed).

[0109] Specifically, the bearing displacement change rate x′ can be obtained by real-time bearing displacement detection and calculation using the bearing controller sensor, and then sent to the main control unit; the compressor outlet pressure change rate p′ can be obtained by real-time compressor outlet pressure detection using the pressure sensor; the compressor inlet flow rate change rate Q′ can be calculated by measuring the real-time inlet flow rate using the (nozzle standard tube); and the motor vibration change rate (motor vibration amplitude) A. f This can be detected by setting a magnetoelectric vibration sensor at a specific location on the main motor.

[0110] If we detect the displacement change rate x′ of the magnetic levitation bearing, the compressor outlet pressure change rate p′, the compressor inlet flow rate change rate Q′, and the motor vibration amplitude A... f If any parameter value in θ does not exceed its corresponding maximum value during normal operation, then surge is not considered to occur. If any of the above parameter values ​​does not exceed its corresponding maximum value during normal operation, it indicates that the system is currently in normal operation, and the valve opening θ... 阀 When the pressure is still very high, surge will not occur yet. Continue to update and record the compressor outlet pressure P at this time. 出口 and the parameter values ​​(m, n, a) of each calibration parameter of the system operation 参数 b 参数 c 参数 d 参数 ,...).

[0111] After the current calibration point is calibrated, the next calibration point at the current calibration frequency is calibrated, and the initial value e of the maximum pressure deviation at that point is set. min Reassign the value to the maximum pressure P maxA new calibration is performed, continuing to reduce the valve opening until the final limit parameter point of the data set is reached. When surge is detected, the parameters stored at the most recently recorded point are the limit parameters and copied to (m, 0xFF, A, B, C, D, ...). The calibration of the m-th data set is now complete. The vent valve is opened, the proportional valve is set to 100% opening, the motor frequency is increased by Δf, and the calibration of the m+1-th data set is performed. The above steps are repeated until all data sets are calibrated.

[0112] The calibration unit is also used to: complete the calibration of the compressor performance curve reference point after recording the parameter values ​​of each calibration parameter at each calibration point under each preset calibration frequency.

[0113] Specifically, calibration is complete when the parameter values ​​of each calibration point at each preset calibration frequency have been recorded.

[0114] Optionally, the device 100 further includes: a storage unit for storing calibration data of calibration points at each preset calibration frequency locally, and / or a transmission unit for transmitting calibration data of calibration points at each preset calibration frequency to a host computer.

[0115] Specifically, when each calibration point data is stored in the local space of the main control unit, it can be simultaneously sent to the host computer. After calibration is completed, the host computer can also read all the stored calibration data in a unified manner. During the calibration process, the air compressor human-machine interface is calibrating and displays the current calibration progress, such as the values ​​of m and n, and the real-time values ​​of various operating parameters of the air compressor, such as parameter a, parameter b, parameter c, etc.

[0116] The present invention also provides a storage medium corresponding to the calibration method of the compressor performance curve reference point, wherein a computer program is stored thereon, and the program, when executed by a processor, implements the steps of any of the aforementioned methods.

[0117] The present invention also provides a compressor corresponding to the calibration method of the compressor performance curve reference point, comprising a processor, a memory, and a computer program stored in the memory that can run on the processor, wherein the processor executes the program to implement the steps of any of the aforementioned methods.

[0118] The present invention also provides a compressor corresponding to the calibration device for the compressor performance curve reference point, including any of the aforementioned calibration devices for the compressor performance curve reference point. Specifically, the compressor may be a centrifugal compressor, and more specifically, a magnetically levitated centrifugal air compressor.

[0119] The present invention also provides a computer program product corresponding to the calibration method of the compressor performance curve reference point, including a computer program that, when executed by a processor, implements the steps of any of the aforementioned methods.

[0120] Accordingly, the solution provided by this invention can automatically calibrate the reference point of the compressor performance curve and store the calibration point of the entire compressor. It comprehensively analyzes multiple key parameters, including pressure fluctuations, flow changes, vibration signals, and magnetic bearing displacement, to determine surge. After testing, the data can be exported from a host computer and curve fitted, ensuring the integrity and accuracy of the data. This solution significantly reduces the need for manual intervention and improves testing efficiency and data accuracy.

[0121] The technical solution of this invention enables the automatic detection and analysis of surge phenomena, completely eliminating the need for traditional manual intervention. This not only significantly improves the consistency and accuracy of calibration data but also effectively protects the hearing health of testing personnel. Furthermore, the automation process greatly simplifies the operation procedures and improves overall testing efficiency.

[0122] The technical solution of this invention eliminates the reliance on the sensory perception of testers, reduces data calibration errors, and improves the consistency and accuracy of calibration data.

[0123] The technical solution of this invention ensures the accuracy of calibration data through automated calibration, avoiding data deviations caused by human factors.

[0124] The technical solution of this invention requires no manual intervention, reduces the time testers are exposed to high-noise environments, lowers the risk of hearing damage, reduces the need for testers, and thus reduces labor costs.

[0125] The functions described herein can be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions can be stored as one or more instructions or codes on or transmitted via a computer-readable medium. Other examples and embodiments are within the scope and spirit of this invention and the appended claims. For example, due to the nature of software, the functions described above can be implemented using software executed by a processor, hardware, firmware, hardwired, or any combination thereof. Furthermore, the functional units can be integrated into a single processing unit, or each unit can exist physically separately, or two or more units can be integrated into a single unit.

[0126] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0127] The units described as separate components may or may not be physically separate. Similarly, the components of the control device may or may not be physical units; they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0128] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to related technologies, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0129] 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 method for calibrating a reference point for a compressor performance curve, characterized in that, include: The operating frequency of the compressor is controlled to be increased sequentially to different preset calibration frequencies. Each time the frequency is increased to a preset calibration frequency, a set of calibration points are calibrated. Specifically, when calibrating the calibration points at each preset calibration frequency, starting from the compressor outlet pressure corresponding to the preset initial calibration point, a calibration point is established at each preset pressure value. The parameter values ​​of each calibration parameter at each calibration point are recorded as the calibration data for that calibration point. When the parameter values ​​of each calibration point at each preset calibration frequency have been recorded, the calibration of the compressor performance curve reference point is completed; Record the parameter values ​​of each calibration point as the calibration data for that calibration point, including: The proportional valve is controlled to decrease the preset opening value each time, and the compressor outlet pressure is detected. When the compressor outlet pressure reaches the compressor outlet pressure corresponding to the calibration point, the calibration data of the current calibration point is recorded. or, Record the parameter values ​​of each calibration point as the calibration data for that calibration point, including: The proportional valve opening is controlled to decrease from 100% to a preset opening value each time. The calibration of each calibration point is performed based on the pressure deviation between the detected compressor outlet pressure and the compressor outlet pressure corresponding to each calibration point.

2. The method according to claim 1, characterized in that, Based on the pressure deviation between the detected compressor outlet pressure and the compressor outlet pressure corresponding to each calibration point, calibration is performed at each calibration point, including: For the current calibration point, after each time the proportional valve opening is reduced by a preset opening value, it is determined whether the pressure deviation between the detected current compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is less than a preset pressure deviation threshold. If it is determined that the pressure deviation between the current compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is less than the preset pressure deviation threshold, then it is further determined whether the current compressor outlet pressure is the compressor outlet pressure with the smallest absolute value of the pressure deviation between the current compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point within the range of pressure deviation less than the preset pressure deviation threshold. If it is determined that the current compressor outlet pressure is the compressor outlet pressure with the smallest absolute value of pressure deviation from the compressor outlet pressure corresponding to the current calibration point within the range of less than the preset pressure deviation threshold, then the parameter values ​​of each calibration parameter are recorded as the parameter values ​​of each calibration parameter at the current calibration point. Specifically, after each time the proportional valve opening is reduced by a preset opening value, it is determined whether surge has occurred. If surge has occurred, the parameter values ​​of each calibration parameter are recorded as the parameter values ​​of each calibration parameter corresponding to the current calibration point, and the surge critical point parameter is recorded. If surge has not occurred, the calibration of the next calibration point continues.

3. The method according to claim 2, characterized in that, Determine whether the current compressor outlet pressure is within the range where the pressure deviation from the compressor outlet pressure corresponding to the current calibration point is less than a preset pressure deviation threshold, and which compressor outlet pressure has the smallest absolute value of pressure deviation from the compressor outlet pressure corresponding to the current calibration point, including: Determine whether the absolute value of the pressure deviation between the current compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is less than e. min , where e min e represents the minimum pressure deviation between the current compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point. min The initial value is equal to the maximum outlet pressure of the compressor; When the absolute value of the pressure deviation between the current compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is less than e min At that time, the absolute value of the pressure deviation between the current compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is assigned to emin, which is used as the new emin. min This process continues until the absolute value of the pressure deviation between the compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is not less than e. min At that time, determine the current e min The value is the compressor outlet pressure with the smallest absolute value of the pressure deviation from the compressor outlet pressure corresponding to the current calibration point.

4. The method according to claim 3, characterized in that, If the current compressor outlet pressure is determined to be the compressor outlet pressure with the smallest absolute value of pressure deviation from the compressor outlet pressure corresponding to the current calibration point, within a range where the pressure deviation from the current calibration point is less than a preset pressure deviation threshold, then the parameter values ​​of each calibration parameter are recorded as the parameter values ​​of each calibration parameter at the current calibration point, including: Determine whether the absolute value of the pressure deviation between the current compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is less than e. min If so, record the current values ​​of each calibration parameter as intermediate data for the parameter values ​​of each calibration parameter at the current calibration point, continue to control the proportional valve to close, and continue to determine whether the absolute value of the pressure deviation between the current compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is less than e. min If so, record the current parameter values ​​of each calibration parameter, and update the intermediate record data of the parameter values ​​of each calibration parameter at the current calibration point to the current parameter values. Continue in this manner until the absolute value of the pressure deviation between the compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is detected to be not less than e. min Alternatively, the pressure deviation between the compressor outlet pressure and the compressor outlet pressure corresponding to the current calibration point is greater than the preset pressure deviation threshold.

5. The method according to any one of claims 2-4, characterized in that, Determining whether a surge has occurred includes: If the preset surge judgment time is exceeded, it is determined whether the magnetic levitation bearing displacement change rate, compressor outlet pressure change rate, compressor inlet flow rate change rate, and motor vibration amplitude all exceed the corresponding preset maximum values ​​during normal operation. If, after a preset surge detection time, the rate of change of magnetic levitation bearing displacement, the rate of change of compressor outlet pressure, the rate of change of compressor inlet flow, and the amplitude of motor vibration all exceed their respective maximum values ​​during normal operation, then surge is determined to have occurred.

6. A calibration device for a compressor performance curve reference point, characterized in that, include: The calibration unit is used to control the compressor's operating frequency to increase sequentially to different preset calibration frequencies. Each time the frequency increases to a preset calibration frequency, a set of calibration points are calibrated. Specifically, when calibrating the calibration points at each preset calibration frequency, starting from the compressor outlet pressure corresponding to the preset initial calibration point, a calibration point is established at each preset pressure value. The parameter values ​​of each calibration parameter at each calibration point are recorded as the calibration data for that calibration point. The calibration unit is also used to: complete the calibration of the compressor performance curve reference point after recording the parameter values ​​of each calibration parameter at each calibration point under each preset calibration frequency; The calibration unit records the parameter values ​​of each calibration parameter at each calibration point as the calibration data for that calibration point, including: controlling the proportional valve to decrease the preset opening value each time and detecting the compressor outlet pressure; when the compressor outlet pressure reaches the compressor outlet pressure corresponding to the calibration point, recording the calibration data of the current calibration point. or, The calibration unit records the parameter values ​​of each calibration parameter at each calibration point as the calibration data for that calibration point, including: controlling the opening of the proportional valve to decrease the preset opening value each time starting from 100%, and calibrating each calibration point according to the pressure deviation between the detected compressor outlet pressure and the compressor outlet pressure corresponding to each calibration point.

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

8. A compressor, characterized in that, It includes a processor, a memory, and a computer program stored in the memory that can run on the processor, wherein the processor executes the program to implement the steps of any one of the methods of claims 1-5, or includes the calibration device as described in claim 6.

9. A computer program product, characterized in that, Includes a computer program, which, when executed by a processor, implements the steps of the method according to any one of claims 1-5.

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