Method and device for diagnosing eccentricity of rotor of asynchronous motor

Abstract

This invention discloses a method and apparatus for diagnosing rotor eccentricity faults in an asynchronous motor. The method includes: acquiring first operating data of the asynchronous motor at multiple times; determining the first rotational speed of the asynchronous motor at each time based on the first instantaneous single-phase current signal at each time; dividing the first operating data at multiple times into sections based on the first rotational speed at each time and multiple preset rotational speed ranges to obtain the rotational speed range, characteristic frequency vector, and amplitude characteristic vector corresponding to each section; calculating the amplitude monitoring threshold corresponding to each first characteristic frequency in the corresponding section using the 3σ criterion based on the amplitude characteristic vector; and diagnosing eccentricity faults in the asynchronous motor under test based on the amplitude monitoring thresholds corresponding to each first characteristic frequency in different sections. The amplitude monitoring thresholds at different rotational speeds are constructed based on statistical principles, overcoming the problem of diagnostic failure due to fluctuations in rotational speed and load.

Description

Technical Field

[0001] This invention relates to the field of fault diagnosis, and in particular to a method and apparatus for diagnosing rotor eccentricity faults in asynchronous motors. Background Technology

[0002] Electric motors are crucial equipment in industrial and mining enterprises, driving the vast majority of equipment. Due to their widespread use and the fact that they typically operate continuously for extended periods in harsh environments, motor malfunctions are inevitable. A failure in an asynchronous motor not only damages the motor itself but also affects the entire transmission system. On complex production lines, if a critical motor malfunctions and is not detected and maintained promptly, the quality of products across the entire production line will be affected, potentially leading to serious production accidents and economic losses.

[0003] Motor rotor eccentricity faults include static eccentricity, dynamic eccentricity, and mixed eccentricity. Mixed eccentricity faults are the most common type encountered in actual production. Patent CN109031118A describes a method for sampling the stator current of a motor to obtain sampled stator current data; processing this data to obtain a first current spectrum of the stator current; and then using this first current spectrum to diagnose motor faults.

[0004] The aforementioned rotor eccentricity fault diagnosis algorithm focuses on the change of a single characteristic frequency component. In actual production processes, motors generally operate under more complex conditions, with speed and load constantly changing. The aforementioned rotor eccentricity fault diagnosis algorithm does not take this issue into account and sets a single threshold during the calculation process, which may lead to diagnosis failure. In actual production processes, motors may be powered by inverters or frequency converters, and the presence of high-order harmonics may cause the aforementioned rotor eccentricity fault diagnosis algorithm to fail to diagnose asynchronous motors. Summary of the Invention

[0005] To address the aforementioned technical problems, embodiments of the present invention provide a method for diagnosing rotor eccentricity faults in asynchronous motors.

[0006] A first aspect of this invention provides a method for diagnosing rotor eccentricity faults in an asynchronous motor, the method comprising:

[0007] Acquire first operating data of the asynchronous motor at multiple moments, the first operating data including the first instantaneous single-phase current signal of the asynchronous motor and the corresponding first characteristic frequency;

[0008] The first speed of the asynchronous motor at the corresponding moment is determined based on the first instantaneous single-phase current signal at each moment;

[0009] Based on the first rotational speed at each moment and multiple preset rotational speed ranges, the first operating data at multiple moments are divided into compartments to obtain the rotational speed range, characteristic frequency vector, and amplitude characteristic vector corresponding to each compartment. The characteristic frequency vector includes the first characteristic frequency corresponding to the first rotational speed within the corresponding rotational speed range, and the amplitude characteristic vector includes the amplitude of the rotor eccentricity fault in the first instantaneous single-phase current signal corresponding to the first rotational speed within the corresponding rotational speed range.

[0010] Based on the amplitude feature vector, the amplitude monitoring threshold corresponding to each first characteristic frequency in the corresponding compartment is calculated using the 3σ criterion.

[0011] Based on the amplitude monitoring threshold corresponding to each first characteristic frequency in different compartments, the asynchronous motor under test is diagnosed for eccentricity fault.

[0012] Optionally, the step of performing eccentric fault diagnosis on the asynchronous motor under test based on the amplitude monitoring threshold corresponding to each first characteristic frequency in different compartments includes:

[0013] The second operating data of the asynchronous motor under test at different times within the sampling time period is obtained. The second operating data includes the second instantaneous single-phase current signal of the asynchronous motor under test and the corresponding second characteristic frequency.

[0014] The second rotational speed of the asynchronous motor at the corresponding moment is determined based on the second instantaneous single-phase current signal at each moment;

[0015] Based on the second rotational speed and the rotational speed range corresponding to each compartment, the compartment corresponding to the second rotational speed is determined, wherein the second rotational speed is within the rotational speed range corresponding to the corresponding compartment;

[0016] When the second instantaneous single-phase current signal corresponding to the second rotational speed at multiple consecutive sampling moments exceeds the corresponding amplitude monitoring threshold, the eccentricity state of the asynchronous motor under test is determined to be abnormal. Herein, the number of the multiple consecutive sampling moments is greater than 3, the second rotational speed at the multiple consecutive sampling moments is in the same compartment, and the corresponding amplitude monitoring threshold is the amplitude monitoring threshold of the first characteristic frequency corresponding to the second characteristic frequency within the compartment.

[0017] Optionally, determining that the eccentricity state of the asynchronous motor under test is abnormal at the same time or after includes:

[0018] Call the alarm.

[0019] Optionally, the first instantaneous single-phase current signal includes instantaneous current signals of different phases of the asynchronous motor.

[0020] Optionally, acquiring the first operating data of the asynchronous motor at multiple times includes:

[0021] The instantaneous single-phase current signals of different phases of the asynchronous motor are synchronously acquired to obtain the first instantaneous single-phase current signal at the corresponding moment;

[0022] The first instantaneous single-phase current signal at each moment is processed by FFT to determine the first characteristic frequency of the asynchronous motor at the corresponding moment.

[0023] A second aspect of the present invention provides an asynchronous motor rotor eccentricity fault diagnosis device, the device comprising:

[0024] The data acquisition module is used to acquire the first operating data of the asynchronous motor at multiple moments, wherein the first operating data includes the first instantaneous single-phase current signal of the asynchronous motor and the corresponding first characteristic frequency;

[0025] The first calculation module is used to determine the first speed of the asynchronous motor at the corresponding moment based on the first instantaneous single-phase current signal at each moment;

[0026] The compartment processing module is used to perform compartment processing on the first operating data at multiple times according to the first rotation speed at each time and multiple preset rotation speed ranges, to obtain the rotation speed range, characteristic frequency vector and amplitude characteristic vector corresponding to each compartment. The characteristic frequency vector includes the first characteristic frequency corresponding to the first rotation speed in the corresponding rotation speed range, and the amplitude characteristic vector includes the amplitude of the rotor eccentricity fault in the first instantaneous single-phase current signal corresponding to the first rotation speed in the corresponding rotation speed range.

[0027] The second calculation module is used to calculate the amplitude monitoring threshold corresponding to each first characteristic frequency in the corresponding compartment based on the amplitude feature vector and the 3σ criterion.

[0028] The diagnostic module is used to diagnose eccentricity faults in the asynchronous motor under test based on the amplitude monitoring threshold corresponding to each first characteristic frequency in different compartments.

[0029] Optionally, the diagnostic module includes:

[0030] The data acquisition submodule is used to acquire the second operating data of the asynchronous motor under test at different times within the sampling time period. The second operating data includes the second instantaneous single-phase current signal of the asynchronous motor under test and the corresponding second characteristic frequency.

[0031] The calculation submodule is used to determine the second speed of the asynchronous motor at the corresponding time based on the second instantaneous single-phase current signal at each time.

[0032] The compartment determination submodule is used to determine the compartment corresponding to the second speed based on the second speed and the speed range corresponding to each compartment, wherein the second speed is within the speed range corresponding to the corresponding compartment.

[0033] The diagnostic submodule determines that the eccentricity state of the asynchronous motor under test is abnormal when the second instantaneous single-phase current signal corresponding to the second rotational speed at multiple consecutive sampling moments exceeds the corresponding amplitude monitoring threshold. The number of consecutive sampling moments is greater than 3, the second rotational speed at the multiple consecutive sampling moments is in the same compartment, and the corresponding amplitude monitoring threshold is the amplitude monitoring threshold of the first characteristic frequency corresponding to the second characteristic frequency within the compartment.

[0034] Optionally, it also includes:

[0035] The alarm module is used to issue an alarm at the same time or after the diagnostic submodule determines that the eccentricity state of the asynchronous motor under test is abnormal.

[0036] Optionally, the first instantaneous single-phase current signal includes instantaneous current signals of different phases of the asynchronous motor.

[0037] Optionally, the data acquisition module includes:

[0038] The acquisition submodule is used to synchronously acquire the instantaneous single-phase current signals of different phases of the asynchronous motor to obtain the first instantaneous single-phase current signal at the corresponding moment.

[0039] The processing submodule is used to perform FFT processing on the first instantaneous single-phase current signal at each time to determine the first characteristic frequency of the asynchronous motor at the corresponding time.

[0040] In the technical solution provided by this invention, multiple characteristic frequencies are constructed to monitor the operating status of the asynchronous motor, monitoring indicators are adaptively constructed, and amplitude monitoring thresholds are automatically calculated. The real-time speed of the asynchronous motor during operation is taken into account, and amplitude monitoring thresholds at different speeds are constructed based on statistical principles. This overcomes the problem of diagnostic failure due to speed and load fluctuations, simplifies manual operation, and improves the accuracy of the monitoring model by applying multiple frequency features and combining them with the actual operating speed of the asynchronous motor. This enhances the accuracy of rotor eccentricity diagnosis. Attached Figure Description

[0041] Figure 1 This is a flowchart illustrating an asynchronous motor rotor eccentricity fault diagnosis method according to an embodiment of the present invention.

[0042] Figure 2This is a schematic diagram of the implementation process of diagnosing eccentricity faults in an asynchronous motor under test based on the amplitude monitoring threshold corresponding to each first characteristic frequency in different compartments, according to one embodiment of the present invention.

[0043] Figure 3 This is a structural block diagram of an asynchronous motor rotor eccentricity fault diagnosis device according to an embodiment of the present invention;

[0044] Figure 4 This is a structural block diagram of a diagnostic module according to an embodiment of the present invention;

[0045] Figure 5 This is a structural block diagram of a data module according to one embodiment of the present invention;

[0046] Figure 6 This is a structural block diagram of an asynchronous motor rotor eccentricity fault diagnosis device according to another embodiment of the present invention. Detailed Implementation

[0047] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] It should be noted that the following embodiments can be combined where there is no conflict.

[0049] Figure 1 This is a flowchart illustrating a method for diagnosing rotor eccentricity faults in an asynchronous motor according to an embodiment of the present invention. The executing entity of the method for diagnosing rotor eccentricity faults in an asynchronous motor according to this embodiment can be any processor, device, or equipment with data capabilities.

[0050] like Figure 1 As shown, the asynchronous motor rotor eccentricity fault diagnosis method of this embodiment of the invention may include steps S11 to S15.

[0051] In step S11, the first operating data of the asynchronous motor at multiple times is obtained. The first operating data includes the first instantaneous single-phase current signal of the asynchronous motor and the corresponding first characteristic frequency.

[0052] In some embodiments, the first instantaneous single-phase current signal includes the instantaneous current signal of the asynchronous motor in a certain phase. For example, the asynchronous motor is a three-phase motor, including phase A, phase B and phase C, and the first instantaneous single-phase current signal can be the instantaneous current signal of phase A, the instantaneous current signal of phase B, or the instantaneous current signal of phase C.

[0053] In other embodiments, the first instantaneous single-phase current signal includes instantaneous current signals of different phases of the asynchronous motor. For example, if the asynchronous motor is a three-phase motor including phase A, phase B, and phase C, the first instantaneous single-phase current signal may include the instantaneous current signals of phase A, phase B, and phase C, or the first instantaneous single-phase current signal may be two of the instantaneous current signals of phase A, phase B, and phase C.

[0054] It should be noted that when the first instantaneous single-phase current signal includes instantaneous current signals from different phases, subsequent rotor eccentricity fault diagnosis of the asynchronous motor under test requires comparing the instantaneous current signals of each phase of the asynchronous motor under test with the corresponding instantaneous current signals of the first instantaneous single-phase current signal. For example, phase A of the asynchronous motor under test needs to be compared with phase A of the first instantaneous single-phase current signal, phase B of the asynchronous motor under test needs to be compared with phase B of the first instantaneous single-phase current signal, and phase C of the asynchronous motor under test needs to be compared with phase C of the first instantaneous single-phase current signal.

[0055] In addition, the asynchronous motor under test and the asynchronous motor in step S11 can be the same asynchronous motor, or the asynchronous motor under test and the asynchronous motor in step S11 can be the same model of asynchronous motor, thus ensuring the accuracy of fault diagnosis.

[0056] For embodiments where the first instantaneous single-phase current signal includes instantaneous current signals of different phases of the asynchronous motor, obtaining the first operating data of the asynchronous motor at multiple moments may specifically include the following steps:

[0057] (1) Synchronously acquire the instantaneous single-phase current signals of different phases of the asynchronous motor to obtain the first instantaneous single-phase current signal at the corresponding moment.

[0058] (2) Perform FFT (Fast Fourier Transform) processing on the first instantaneous single-phase current signal at each moment to determine the first characteristic frequency of the asynchronous motor at the corresponding moment.

[0059] The first characteristic frequency is adaptively calculated by utilizing the parameters of the asynchronous motor itself (i.e., the first instantaneous single-phase current information), which overcomes the problem of asynchronous motor fault diagnosis failure caused by harmonics due to the use of inverters or frequency converters for power supply during the operation of the asynchronous motor.

[0060] For example, when a rotor air gap eccentricity fault occurs, the air gap magnetic permeability becomes uneven along the circumferential direction, thereby inducing harmonic components in the stator current. The corresponding first characteristic frequency can be calculated based on the monitored instantaneous single-phase current.

[0061] In step S12, according to the first instantaneous single-phase current signals at each moment, the first speed of the asynchronous motor at the corresponding moment is determined.

[0062] The first speed is the real-time speed of the asynchronous motor.

[0063] Among them, step S12 can be implemented by a conventional calculation method.

[0064] In step S13, according to the first speeds at each moment and a plurality of preset speed ranges, the first operating data at multiple moments are subjected to binning processing to obtain the speed range, characteristic frequency vector, and amplitude characteristic vector corresponding to each bin. Among them, the characteristic frequency vector includes the first characteristic frequency corresponding to the first speed within the corresponding speed range, and the amplitude characteristic vector includes the amplitude representing the rotor eccentricity fault in the first instantaneous single-phase current signal corresponding to the first speed within the corresponding speed range.

[0065] For example, the plurality of preset speed ranges include [V1, V2), (V2, V3], (V3, V4], where V1 < V2 < V3 < V4. Bin 1 corresponds to [V1, V2), bin 2 corresponds to (V2, V3], and bin 3 corresponds to (V3, V4]. The first speeds at different moments include V11, V12, V13, V14, V15, V16, V17, where V1 ≤ V11 < V2, V1 ≤ V12 < V2, V1 ≤ V13 < V2, V2 ≤ V14 < V3, V2 ≤ V15 < V3, V3 ≤ V16 < V4, V3 ≤ V17 < V4. The binning processing result is: V11, V12, and V13 are in bin 1, corresponding to [V1, V2); V14 and V15 are in bin 2, corresponding to (V2, V3]; V16 and V17 are in bin 3, corresponding to (V3, V4].

[0066] Among them, the characteristic frequency vector corresponding to bin 1 includes the first characteristic frequencies corresponding to V11, V12, and V13 respectively, and the amplitude characteristic vector corresponding to bin 1 includes the first instantaneous single-phase current signals corresponding to V11, V12, and V13 respectively. The characteristic frequency vector corresponding to bin 2 includes the first characteristic frequencies corresponding to V14 and V15 respectively, and the amplitude characteristic vector corresponding to bin 2 includes the first instantaneous single-phase current signals corresponding to V14 and V15 respectively. The characteristic frequency vector corresponding to bin 3 includes the first characteristic frequencies corresponding to V16 and V17 respectively, and the amplitude characteristic vector corresponding to bin 3 includes the first instantaneous single-phase current signals corresponding to V16 and V17 respectively.

[0067] Specifically, the first characteristic frequency of the first instantaneous single-phase current signal to be analyzed is determined to form a characteristic frequency vector, f 1×M= [f1, f2, ...], where M is the number of selected first characteristic frequencies. Calculate the amplitude of each first characteristic frequency representing the rotor eccentricity fault in the acquired first instantaneous single-phase current signal, i.e., the amplitude of the rotor eccentricity fault in the first instantaneous single-phase current signal corresponding to the first rotational speed, forming the amplitude feature vector y. 1×M =[y1,y2,…].

[0068] Among them, the amplitude representing the rotor eccentricity fault in the first instantaneous single-phase current signal corresponding to each first characteristic frequency refers to the minimum value representing the rotor eccentricity fault in the first instantaneous single-phase current signal of each first characteristic frequency.

[0069] Within each compartment, the characteristic frequency vector and characteristic amplitude vector obtained above are saved for easy access during fault diagnosis of the asynchronous motor under test.

[0070] The speed range can be set as needed to meet different fault diagnosis requirements.

[0071] In step S14, based on the amplitude feature vector, the amplitude monitoring threshold corresponding to each first feature frequency in the corresponding compartment is calculated using the 3σ criterion.

[0072] In this way, amplitude monitoring thresholds at different rotational speeds are established.

[0073] The amplitude eigenvector y is used to calculate the amplitude monitoring threshold σ using the 3σ criterion. 1×M =[σ1,σ2,…].

[0074] For the sample data in each compartment, the 3σ calculation steps for the amplitude corresponding to each first characteristic frequency are as follows:

[0075] 1) Calculate the average value μ of the amplitude corresponding to the first characteristic frequency;

[0076] 2) Calculate the standard deviation σ of the amplitude corresponding to the first characteristic frequency;

[0077] 3) Then the amplitude monitoring threshold σ1=μ+3σ.

[0078] Calculate the amplitude monitoring threshold for each compartment separately, and simultaneously record the rotational speed in different compartments to construct an amplitude monitoring threshold library σ for different rotational speeds. N×M N is the number of sub-warehouses.

[0079] In step S15, based on the amplitude monitoring threshold corresponding to each first characteristic frequency in different compartments, the asynchronous motor under test is diagnosed for eccentricity fault.

[0080] Specifically, see Figure 2A process for diagnosing eccentricity faults in an asynchronous motor under test based on amplitude monitoring thresholds corresponding to the first characteristic frequencies in different compartments may include steps S151 to S154.

[0081] Step S151: Obtain the second operating data of the asynchronous motor under test at different times during the sampling period. The second operating data includes the second instantaneous single-phase current signal of the asynchronous motor under test and the corresponding second characteristic frequency.

[0082] The method of obtaining the second running data in step S151 is similar to the method of obtaining the first running data in step S11, and will not be described again here.

[0083] Step S152: Determine the second speed of the asynchronous motor at the corresponding moment based on the second instantaneous single-phase current signal at each moment.

[0084] The method for determining the second rotational speed in step S152 is similar to the method for determining the first rotational speed in step S12, and will not be described again here.

[0085] Step S153: Determine the compartment corresponding to the second speed based on the second speed and the speed range corresponding to each compartment, wherein the second speed is within the speed range corresponding to the corresponding compartment.

[0086] Step S154: When the second instantaneous single-phase current signal corresponding to the second rotational speed at multiple consecutive sampling moments exceeds the corresponding amplitude monitoring threshold, the eccentricity state of the asynchronous motor under test is determined to be abnormal. Among them, the number of multiple consecutive sampling moments is greater than 3, the second rotational speed at multiple consecutive sampling moments is in the same compartment, and the corresponding amplitude monitoring threshold is the amplitude monitoring threshold of the first characteristic frequency corresponding to the second characteristic frequency within the compartment.

[0087] Specifically, based on the second instantaneous single-phase current signal, the amplitude vector y_temp at the second characteristic frequency is extracted. 1×N =[y1,y2,…], determine the corresponding speed range based on the second speed, and compare it with the amplitude monitoring threshold of the corresponding amplitude feature vector.

[0088] It should be understood that the number 3 can also be set to other values ​​as needed.

[0089] Optionally, in some embodiments, an alarm is triggered simultaneously with or after determining that the eccentricity state of the asynchronous motor under test is abnormal. The alarm method can be selected as needed, for example, outputting an audible alarm signal and / or outputting an alarm signal on a display interface.

[0090] The asynchronous motor rotor eccentricity fault diagnosis method of the present invention is applicable to the monitoring of rotor eccentricity status of asynchronous motors.

[0091] The asynchronous motor rotor eccentricity fault diagnosis method of this invention monitors the operating status of the asynchronous motor by constructing multiple characteristic frequencies, adaptively constructing monitoring indicators, automatically calculating amplitude monitoring thresholds, and taking into account the real-time speed of the asynchronous motor during operation. Based on statistical principles, amplitude monitoring thresholds at different speeds are constructed, overcoming the problem of diagnosis failure due to speed and load fluctuations, and simplifying manual operation. By applying multiple frequency features and combining them with the actual operating speed of the asynchronous motor, the accuracy of the monitoring model is improved, thereby enhancing the accuracy of rotor eccentricity diagnosis.

[0092] Corresponding to the asynchronous motor rotor eccentricity fault diagnosis method in the above embodiments, the present invention also provides an asynchronous motor rotor eccentricity fault diagnosis device.

[0093] See Figure 3 The asynchronous motor rotor eccentricity fault diagnosis device in this embodiment of the invention may include:

[0094] The data acquisition module 101 is used to acquire the first operating data of the asynchronous motor at multiple moments. The first operating data includes the first instantaneous single-phase current signal of the asynchronous motor and the corresponding first characteristic frequency.

[0095] The first calculation module 102 is used to determine the first speed of the asynchronous motor at the corresponding moment based on the first instantaneous single-phase current signal at each moment;

[0096] The compartment processing module 103 is used to perform compartment processing on the first operating data at multiple times according to the first speed at each time and multiple preset speed ranges, to obtain the speed range, characteristic frequency vector and amplitude characteristic vector corresponding to each compartment. The characteristic frequency vector includes the first characteristic frequency corresponding to the first speed in the corresponding speed range, and the amplitude characteristic vector includes the amplitude of the rotor eccentricity fault in the first instantaneous single-phase current signal corresponding to the first speed in the corresponding speed range.

[0097] The second calculation module 104 is used to calculate the amplitude monitoring threshold corresponding to each first characteristic frequency in the corresponding compartment based on the amplitude feature vector and the 3σ criterion.

[0098] The diagnostic module 105 is used to diagnose eccentricity faults in the asynchronous motor under test based on the amplitude monitoring threshold corresponding to each first characteristic frequency in different compartments.

[0099] See Figure 4 The diagnostic module includes:

[0100] The data acquisition submodule 1051 is used to acquire the second operating data of the asynchronous motor under test at different times during the sampling time period. The second operating data includes the second instantaneous single-phase current signal of the asynchronous motor under test and the corresponding second characteristic frequency.

[0101] The calculation submodule 1052 is used to determine the second speed of the asynchronous motor at the corresponding moment based on the second instantaneous single-phase current signal at each moment;

[0102] The compartment determination submodule 1053 is used to determine the compartment corresponding to the second speed based on the second speed and the speed range corresponding to each compartment, wherein the second speed is within the speed range corresponding to the corresponding compartment.

[0103] The diagnostic submodule 1054 determines that the eccentricity state of the asynchronous motor under test is abnormal when the second instantaneous single-phase current signal corresponding to the second speed at multiple consecutive sampling moments exceeds the corresponding amplitude monitoring threshold. Among them, the number of multiple consecutive sampling moments is greater than 3, the second speed at multiple consecutive sampling moments is in the same compartment, and the corresponding amplitude monitoring threshold is the amplitude monitoring threshold of the first characteristic frequency corresponding to the second characteristic frequency in the compartment.

[0104] Optionally, it also includes an alarm module for triggering an alarm at the same time or after the diagnostic module determines that the eccentricity of the asynchronous motor under test is abnormal.

[0105] Optionally, the first instantaneous single-phase current signal includes instantaneous current signals of different phases of the asynchronous motor.

[0106] Optionally, the data acquisition module 101 includes:

[0107] The acquisition submodule 1011 is used to synchronously acquire the instantaneous single-phase current signals of different phases of the asynchronous motor to obtain the first instantaneous single-phase current signal at the corresponding moment.

[0108] The processing submodule 1012 is used to perform FFT processing on the first instantaneous single-phase current signal at each time to determine the first characteristic frequency of the asynchronous motor at the corresponding time.

[0109] See Figure 6 The present invention provides an asynchronous motor rotor eccentricity fault diagnosis device, including a memory and one or more processors. The memory stores executable code, and when the one or more processors execute the executable code, they are used to implement the asynchronous motor rotor eccentricity fault diagnosis method in the above embodiment.

[0110] The embodiment of the asynchronous motor rotor eccentricity fault diagnosis device provided in this invention can be applied to any device with data processing capabilities, such as a computer. The device embodiment can be implemented in software, hardware, or a combination of both. Taking software implementation as an example, as a logical device, it is formed by the processor of any data processing device reading the corresponding computer program instructions from non-volatile memory into memory and executing them. From a hardware perspective, such as... Figure 6 The diagram shown is a hardware structure diagram of any device with data processing capabilities, including the asynchronous motor rotor eccentricity fault diagnosis device provided in this embodiment of the invention. (Except for...) Figure 6 In addition to the processor, memory, network interface, and non-volatile memory shown, any data processing device in the embodiment may also include other hardware depending on the actual function of the data processing device, which will not be described in detail here.

[0111] The specific implementation process of the functions and roles of each unit in the above device can be found in the implementation process of the corresponding steps in the above method, and will not be repeated here.

[0112] For the device embodiments, since they basically correspond to the method embodiments, the relevant parts can be referred to in the description of the method embodiments. The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of the present invention according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0113] This invention also provides a computer-readable storage medium storing a program thereon, which, when executed by a processor, implements the asynchronous motor rotor eccentricity fault diagnosis method described in the above embodiments.

[0114] The computer-readable storage medium can be an internal storage unit of any data processing device as described in any of the foregoing embodiments, such as a hard disk or memory. The computer-readable storage medium can also be an external storage device of any data processing device, such as a plug-in hard disk, smart media card (SMC), SD card, flash card, etc., equipped on the device. Furthermore, the computer-readable storage medium can include both internal storage units and external storage devices of any data processing device. The computer-readable storage medium is used to store the computer program and other programs and data required by the data processing device, and can also be used to temporarily store data that has been output or will be output.

[0115] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for diagnosing rotor eccentricity faults in an asynchronous motor, characterized in that, The method includes: Acquire first operating data of the asynchronous motor at multiple moments, the first operating data including the first instantaneous single-phase current signal of the asynchronous motor and the corresponding first characteristic frequency; The first speed of the asynchronous motor at the corresponding moment is determined based on the first instantaneous single-phase current signal at each moment; Based on the first rotational speed at each moment and multiple preset rotational speed ranges, the first operating data at multiple moments are divided into compartments to obtain the rotational speed range, characteristic frequency vector, and amplitude characteristic vector corresponding to each compartment. The characteristic frequency vector includes the first characteristic frequency corresponding to the first rotational speed within the corresponding rotational speed range, and the amplitude characteristic vector includes the amplitude of the rotor eccentricity fault in the first instantaneous single-phase current signal corresponding to the first rotational speed within the corresponding rotational speed range. The amplitudes of each first characteristic frequency representing the rotor eccentricity fault in the first instantaneous single-phase current signal; Based on the amplitude feature vector, the amplitude monitoring threshold corresponding to each first characteristic frequency in the corresponding compartment is calculated using the 3σ criterion. Based on the amplitude monitoring threshold corresponding to each first characteristic frequency in different compartments, the asynchronous motor under test is diagnosed for eccentricity fault. The step of diagnosing eccentricity faults in the asynchronous motor under test based on the amplitude monitoring thresholds corresponding to the first characteristic frequencies in different compartments includes: The second operating data of the asynchronous motor under test at different times within the sampling time period is obtained. The second operating data includes the second instantaneous single-phase current signal of the asynchronous motor under test and the corresponding second characteristic frequency. The second speed of the asynchronous motor under test at the corresponding moment is determined based on the second instantaneous single-phase current signal at each moment; Based on the second rotational speed and the rotational speed range corresponding to each compartment, the compartment corresponding to the second rotational speed is determined, wherein the second rotational speed is within the rotational speed range corresponding to the corresponding compartment; When the second instantaneous single-phase current signal corresponding to the second rotational speed at multiple consecutive sampling moments exceeds the corresponding amplitude monitoring threshold, the eccentricity state of the asynchronous motor under test is determined to be abnormal. Herein, the number of the multiple consecutive sampling moments is greater than 3, the second rotational speed at the multiple consecutive sampling moments is in the same compartment, and the corresponding amplitude monitoring threshold is the amplitude monitoring threshold of the first characteristic frequency corresponding to the second characteristic frequency within the compartment. The first instantaneous single-phase current signal includes the instantaneous current signals of different phases of the asynchronous motor; The acquisition of the first operating data of the asynchronous motor at multiple times includes: The instantaneous single-phase current signals of different phases of the asynchronous motor are synchronously acquired to obtain the first instantaneous single-phase current signal at the corresponding moment; The first instantaneous single-phase current signal at each moment is processed by FFT to determine the first characteristic frequency of the asynchronous motor at the corresponding moment.

2. The method for diagnosing rotor eccentricity faults in an asynchronous motor according to claim 1, characterized in that, The determination of the eccentricity state of the asynchronous motor under test as abnormal, either simultaneously or afterward, includes: Call the alarm.

3. A fault diagnosis device for rotor eccentricity of an asynchronous motor, characterized in that, The device includes: The data acquisition module is used to acquire the first operating data of the asynchronous motor at multiple moments, wherein the first operating data includes the first instantaneous single-phase current signal of the asynchronous motor and the corresponding first characteristic frequency; The first calculation module is used to determine the first speed of the asynchronous motor at the corresponding moment based on the first instantaneous single-phase current signal at each moment; The compartment processing module is used to perform compartment processing on the first operating data at multiple times according to the first rotation speed at each time and multiple preset rotation speed ranges, to obtain the rotation speed range, characteristic frequency vector and amplitude characteristic vector corresponding to each compartment. The characteristic frequency vector includes the first characteristic frequency corresponding to the first rotation speed in the corresponding rotation speed range, and the amplitude characteristic vector includes the amplitude of the rotor eccentricity fault in the first instantaneous single-phase current signal corresponding to the first rotation speed in the corresponding rotation speed range. The second calculation module is used to calculate the amplitude monitoring threshold corresponding to each first characteristic frequency in the corresponding compartment based on the amplitude feature vector and the 3σ criterion. The diagnostic module is used to diagnose eccentricity faults in the asynchronous motor under test based on the amplitude monitoring threshold corresponding to each first characteristic frequency in different compartments.

4. The asynchronous motor rotor eccentricity fault diagnosis device according to claim 3, characterized in that, The diagnostic module includes: The data acquisition submodule is used to acquire the second operating data of the asynchronous motor under test at different times within the sampling time period. The second operating data includes the second instantaneous single-phase current signal of the asynchronous motor under test and the corresponding second characteristic frequency. The calculation submodule is used to determine the second speed of the asynchronous motor under test at the corresponding time based on the second instantaneous single-phase current signal at each time. The compartment determination submodule is used to determine the compartment corresponding to the second speed based on the second speed and the speed range corresponding to each compartment, wherein the second speed is within the speed range corresponding to the corresponding compartment. The diagnostic submodule determines that the eccentricity state of the asynchronous motor under test is abnormal when the second instantaneous single-phase current signal corresponding to the second rotational speed at multiple consecutive sampling moments exceeds the corresponding amplitude monitoring threshold. The number of consecutive sampling moments is greater than 3, the second rotational speed at the multiple consecutive sampling moments is in the same compartment, and the corresponding amplitude monitoring threshold is the amplitude monitoring threshold of the first characteristic frequency corresponding to the second characteristic frequency within the compartment.

5. The asynchronous motor rotor eccentricity fault diagnosis device according to claim 4, characterized in that, Also includes: The alarm module is used to issue an alarm at the same time or after the diagnostic submodule determines that the eccentricity state of the asynchronous motor under test is abnormal.

6. The asynchronous motor rotor eccentricity fault diagnosis device according to claim 3, characterized in that, The first instantaneous single-phase current signal includes the instantaneous current signals of different phases of the asynchronous motor.

7. The asynchronous motor rotor eccentricity fault diagnosis device according to claim 6, characterized in that, The data acquisition module includes: The acquisition submodule is used to synchronously acquire the instantaneous single-phase current signals of different phases of the asynchronous motor to obtain the first instantaneous single-phase current signal at the corresponding moment. The processing submodule is used to perform FFT processing on the first instantaneous single-phase current signal at each time to determine the first characteristic frequency of the asynchronous motor at the corresponding time.

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