Methods, devices, electronic equipment and storage media for diagnosing faults in motor stator windings

Abstract

This invention specifically relates to a method, apparatus, electronic device, and storage medium for diagnosing stator winding faults in a motor. The method includes: acquiring the three-phase stator current and three-phase stator voltage of a target asynchronous motor in a normal state; performing phase sequence analysis on the voltage characteristic spectrum components and current characteristic spectrum components; determining the negative sequence admittance based on the quantitative relationship between the negative sequence current and negative sequence voltage when the target asynchronous motor is in a normal state; determining the positive and negative sequence transfer admittance based on the negative sequence admittance, positive and negative sequence current, and voltage when the target asynchronous motor is in a fault diagnosis state; and determining the fault diagnosis result of the target asynchronous motor based on the positive and negative sequence transfer admittance and the safe region. The beneficial effects of this invention are: achieving high robustness, low computational complexity, and multi-fault category fault diagnosis for motor stator winding faults.

Description

Technical Field

[0001] This invention belongs to the field of motor fault diagnosis technology, specifically relating to a method, device, electronic equipment, and storage medium for diagnosing faults in motor stator windings. Background Technology

[0002] With increasing demands for power supply reliability, there is a growing desire to detect faults before they occur (relay protection trips) and to repair and eliminate them in advance. Furthermore, there is a desire to estimate equipment health and lifespan based on the analysis of fault evolution trends, in order to guide planned maintenance.

[0003] Asynchronous motors (mainly squirrel-cage motors) are the most numerous and consume the largest proportion of electricity in the power grid, and their importance in industry is self-evident. Timely diagnosis of early faults such as stator winding insulation degradation and inter-turn short circuits is crucial for preventing downtime accidents. Research on early fault diagnosis of asynchronous motors has gradually led to product applications. However, existing non-invasive fault diagnosis technologies generally suffer from high false positive rates, complex implementation, insufficient real-time performance, and limited diagnostic scope.

[0004] Existing technologies include Park vector trajectory images and positive / negative sequence component separation for fault identification; however, these technologies have the following drawbacks:

[0005] (1) The Park vector trajectory is susceptible to load fluctuations or grid harmonic interference, resulting in insufficient stability of the feature vector; this method requires the acquisition of a large number of current signals and the generation of images, which has high computational complexity and is difficult to meet the real-time monitoring requirements; and it does not consider the suppression of voltage signal interference to non-fault factors, which may lead to misjudgment.

[0006] (2) Dynamic analysis of oversequence components and screening of voltage imbalance factors reduce the influence of non-fault factors. However, the inherent negative sequence components need to be pre-calibrated, which is difficult to adapt to changes in motor parameters in practical applications; and the fault judgment is based solely on the amplitude of the negative sequence current, resulting in a single dimension.

[0007] (3) It has weak anti-interference ability and poor robustness to changes in motor parameters and dynamic operating conditions (such as load fluctuations and power grid interference). Summary of the Invention

[0008] The main objective of this invention is to propose a method, device, electronic device, and storage medium for diagnosing faults in motor stator windings, achieving high robustness, low computational complexity, and multi-fault category fault diagnosis.

[0009] One aspect of the present invention provides a method for diagnosing faults in the stator windings of an electric motor, comprising:

[0010] The three-phase stator current and three-phase stator voltage of the target asynchronous motor under normal conditions are collected, and the three-phase stator current and three-phase stator voltage are subjected to spectrum analysis to obtain the voltage characteristic spectrum components and the current characteristic spectrum components.

[0011] Phase sequence analysis is performed on the voltage characteristic spectrum components and the current characteristic spectrum components to obtain the positive sequence current, negative sequence current, positive sequence voltage, and negative sequence voltage.

[0012] The target asynchronous motor is in normal condition. The negative sequence admittance is determined by the quantitative relationship between the negative sequence current and the negative sequence voltage.

[0013] The target asynchronous motor is in a fault diagnosis state. The positive and negative sequence transfer admittance is determined based on the quantitative relationship between negative sequence admittance, positive sequence current, negative sequence current, positive sequence voltage, and negative sequence voltage.

[0014] The fault diagnosis result of the target asynchronous motor is determined based on the positive and negative sequence transfer admittance and the safe region, where the safe region is used to determine whether the target asynchronous motor is in a normal state or a fault diagnosis state.

[0015] According to the aforementioned motor stator winding fault diagnosis method, phase sequence analysis is performed on the voltage characteristic spectrum components and current characteristic spectrum components to obtain positive sequence current, negative sequence current, positive sequence voltage, and negative sequence voltage, including:

[0016] The formulas for calculating the positive-sequence current and the negative-sequence current are as follows:

[0017]

[0018] in, , , These are the current characteristic spectrum components of the three-phase stator current. , , and The positive sequence current, negative sequence current, and zero sequence current of the target asynchronous motor in normal state;

[0019] The formulas for calculating the positive-sequence voltage and the negative-sequence voltage are as follows:

[0020]

[0021] in, , , These are the voltage characteristic spectrum components of the three-phase stator voltage. , and The positive sequence voltage, negative sequence voltage, and zero sequence voltage of the target asynchronous motor in normal state indicate that the target asynchronous motor is in system debugging or motor healthy operation.

[0022] According to the aforementioned method for diagnosing stator winding faults in motors, where the target asynchronous motor is in a normal state, the negative sequence admittance is determined through the quantitative relationship between negative sequence current and negative sequence voltage, including:

[0023] Negative-order admittance The calculation formula is:

[0024]

[0025] in, Indicates negative sequence current. Indicates negative sequence voltage;

[0026] And, when the target asynchronous motor is shipped from the factory or undergoes initial commissioning, the negative sequence admittance... During the tuning process, the target asynchronous motor is in fault diagnosis mode, maintaining negative sequence admittance. Constant; or obtain the load and environment during the operation of the target asynchronous motor, and if the degree of change in load and environment is greater than a preset change value, then apply the negative sequence admittance. Perform readjustment; or obtain the running time of the target asynchronous motor, and if the running time exceeds the preset time, adjust the negative sequence admittance. Reconfigure.

[0027] According to the aforementioned method for diagnosing faults in motor stator windings, the method further includes:

[0028] Obtain the nameplate data of the target asynchronous motor, and perform negative-sequence admittance based on the nameplate data. The formula for setting or resetting is:

[0029]

[0030]

[0031]

[0032] in It is a negative sequence impedance. The unit is imaginary; the nameplate data includes stator resistance. Leakage resistance Rotor resistance Leakage resistance Magnetizing Reactor and excitation resistor .

[0033] According to the aforementioned method for diagnosing faults in motor stator windings, the method further includes:

[0034] Negative-order admittance can be determined using the average value method or the least squares method. Perform the adjustment;

[0035] The averaging method includes collecting sample data within a preset period and calculating the negative order admittance of each sample data. Take the average of all data as the negative order admittance. The setpoint, calculated using the average value method, is as follows:

[0036]

[0037] in, For identifying the sequence of sampled data, For the number of sample data, and For the first k Negative sequence voltage and negative sequence current in the sample data. This is the setting value for the negative-order admittance. It is the average value of the negative-order admittance;

[0038] The least squares method includes collecting sample data within a preset period, and based on the negative sequence voltage... With negative sequence current Negative-order admittance using the least squares method The tuning is performed, and the calculation formula for the least squares method is as follows:

[0039]

[0040] in, and These represent the average negative-sequence voltage and the average negative-sequence current of the sample data.

[0041] According to the aforementioned motor stator winding fault diagnosis method, where the target asynchronous motor is in a fault diagnosis state, the positive and negative sequence transfer admittance is determined based on the quantitative relationship between negative sequence admittance, positive sequence current, negative sequence current, positive sequence voltage, and negative sequence voltage, including:

[0042] Positive and negative sequence transit admittance The calculation formula is:

[0043]

[0044] Among them, the positive sequence current, negative sequence current, positive sequence voltage, and negative sequence voltage of the target asynchronous motor in fault diagnosis state are: , , and , It is a negative-order admittance;

[0045] Furthermore, the positive and negative order transfer admittances are calculated using the average value method or the least squares method. ;

[0046] The averaging method includes collecting sample data within a preset period and calculating the positive and negative order admittance of each sample data. The average of all sample data is used as the positive and negative order admittance. The setpoint, calculated using the average value method, is as follows:

[0047]

[0048] in, For identifying the sequence of sampled data, For the number of sample data, , and This refers to the positive-sequence voltage, negative-sequence voltage, and positive-sequence current in the k-th group of sample data during fault diagnosis. This is the setting value for the positive and negative order admittances. It is the average of the positive and negative order admittances;

[0049] The least squares method includes collecting sample data within a preset period, and based on the negative sequence voltage... With negative sequence current For positive and negative order admittance The tuning is performed, and the calculation formula for the least squares method is as follows:

[0050]

[0051] in, and The average negative sequence voltage and average negative sequence current of the sample data.

[0052] According to the aforementioned method for diagnosing stator winding faults in motors, the fault diagnosis results of the target asynchronous motor are determined based on the positive and negative sequence transfer admittance and the safe region, including:

[0053] Determine whether the positive and negative sequence transfer admittances are within the safe region. If they are, the target asynchronous motor is in a healthy state; otherwise, the target asynchronous motor is in a fault state.

[0054] The target asynchronous motor is in a fault state. The fault type is determined based on the magnitude and phase coordinates of the positive and negative sequence admittances, and the fault diagnosis result is determined based on the fault type.

[0055] Another aspect of the present invention provides a motor stator winding fault diagnosis device, comprising:

[0056] The first module is used to collect the three-phase stator current and three-phase stator voltage of the target asynchronous motor in normal condition, and to perform spectrum analysis on the three-phase stator current and three-phase stator voltage to obtain the voltage characteristic spectrum components and the current characteristic spectrum components.

[0057] The second module is used to perform phase sequence analysis on the voltage characteristic spectrum components and the current characteristic spectrum components to obtain positive sequence current, negative sequence current, positive sequence voltage and negative sequence voltage.

[0058] The third module is used to determine the negative sequence admittance by the quantitative relationship between the negative sequence current and the negative sequence voltage when the target asynchronous motor is in normal state.

[0059] The fourth module is used to determine the positive and negative sequence transfer admittance based on the quantitative relationship between negative sequence admittance, positive sequence current, negative sequence current, positive sequence voltage, and negative sequence voltage when the target asynchronous motor is in a fault diagnosis state.

[0060] The fifth module is used to determine the fault diagnosis result of the target asynchronous motor based on the positive and negative sequence transmit admittance and the safe region, where the safe region is used to determine whether the target asynchronous motor is in a normal state or a fault diagnosis state.

[0061] Another aspect of the present invention provides an electronic device, including a processor and a memory;

[0062] The memory is used to store programs;

[0063] The processor executes the program to implement the method as described above.

[0064] This invention also discloses a computer program product or computer program, which includes computer instructions stored in a computer-readable storage medium. A processor of a computer device can read the computer instructions from the computer-readable storage medium and execute the computer instructions, causing the computer device to perform the methods described above.

[0065] The beneficial effects of this invention are as follows: It employs a non-invasive design, requiring only the acquisition of motor voltage and current signals for real-time monitoring without affecting normal equipment operation; the diagnostic process uses only parameters such as voltage and current, directly reusing existing electrical parameter ports without the need for vibration or temperature sensors, significantly reducing diagnostic costs; it identifies a wide range of fault types, using dual diagnosis of characteristic impedance amplitude and phase to identify various faults such as inter-turn short circuits, phase-to-phase insulation abnormalities, open circuits in parallel branches, and high-resistance connections; it uses dynamic parameter estimation and anti-interference algorithms to eliminate the influence of nameplate parameter errors and changes in motor operating points on the results, improving the model's adaptability to unstable voltage conditions and demonstrating good robustness; the calculation is simple, the setting time is short, and it allows for long-term continuous online monitoring. Attached Figure Description

[0066] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0067] Figure 1 This is a schematic diagram of a motor stator winding fault diagnosis system according to an embodiment of the present invention.

[0068] Figure 2 This is a schematic diagram of the data analysis module in an embodiment of the present invention.

[0069] Figure 3 This is a schematic flowchart of a motor stator winding fault diagnosis method according to an embodiment of the present invention.

[0070] Figure 4 This is a schematic flowchart of a motor stator winding fault diagnosis method based on motor nameplate data according to an embodiment of the present invention.

[0071] Figure 5 This is a schematic flowchart of a motor stator winding fault diagnosis method with introduced voltage disturbance according to an embodiment of the present invention.

[0072] Figure 6 This is a schematic flowchart of a motor stator winding fault diagnosis method for setting negative sequence admittance and positive and negative sequence admittance according to an embodiment of the present invention.

[0073] Figure 7 This is a fault characteristic amplitude-phase distribution diagram according to an embodiment of the present invention.

[0074] Figure 8 This is a diagram showing the relationship between diagnostic coefficients, nameplate parameters, and motor operating points in an embodiment of the present invention.

[0075] Figure 9 This is a diagram showing the distribution of fault characteristics before and after a fault in an inter-turn short circuit embodiment of the present invention.

[0076] Figure 10 This is a distribution diagram of the fault characteristics before and after the fault in the parallel branch open circuit fault embodiment of the present invention.

[0077] Figure 11 This is a schematic diagram of a motor stator winding fault diagnosis device according to an embodiment of the present invention. Detailed Implementation

[0078] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings. Throughout the description, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions. In the following description, suffixes such as "module," "part," or "unit" used to denote elements are used only for the purpose of illustrative purposes and have no specific meaning in themselves. Therefore, "module," "part," or "unit" can be used interchangeably. Terms such as "first," "second," etc., are used only to distinguish technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the sequential relationship of the indicated technical features. In the following description, the consecutive reference numerals for method steps are for ease of review and understanding. Adjusting the implementation order of steps, in conjunction with the overall technical solution of the present invention and the logical relationship between the various steps, will not affect the technical effect achieved by the technical solution of the present invention. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0079] like Figure 1 and Figure 2 As shown, Figure 1 This is a schematic diagram of a motor stator winding fault diagnosis system, which includes an asynchronous motor stator winding 100 and a data analysis module 200. Figure 2 This is a schematic diagram of the data analysis module 200. It primarily collects current and voltage data from the stator winding 100 using a group of detection coils. After performing spectral analysis on the collected current and voltage data, it obtains the corresponding component data (i.e., characteristic spectral components). Then, it performs phase sequence analysis to obtain the positive-sequence current, negative-sequence current, positive-sequence voltage, and negative-sequence voltage. When the target asynchronous motor is in a normal state (i.e., stable and healthy operation), the negative-sequence admittance is determined based on the quantitative relationship between the negative-sequence current and negative-sequence voltage. Then, when the target asynchronous motor is in a fault diagnosis state, the positive and negative-sequence transfer admittance is determined based on the quantitative relationship between the negative-sequence admittance, positive-sequence current, negative-sequence current, positive-sequence voltage, and negative-sequence voltage. Finally, the fault diagnosis result of the target asynchronous motor is determined based on the positive and negative-sequence transfer admittance and the safe zone.

[0080] refer to Figure 3 , 4 5 and 6 are schematic diagrams of the fault diagnosis method for motor stator windings, in which... Figure 4 , 5 The data acquisition module in section 6 can be referenced. Figure 2 The data acquisition module shown.

[0081] for Figure 3 This includes, but is not limited to, steps S100~S500:

[0082] S100 collects the three-phase stator current and three-phase stator voltage of the target asynchronous motor in normal condition, performs spectrum analysis on the three-phase stator current and three-phase stator voltage, and obtains the voltage characteristic spectrum component and the current characteristic spectrum component.

[0083] In some embodiments, during system debugging or motor health operation, the three-phase stator current of the asynchronous motor under test is collected. , , And extract the components of specific frequencies. , , Collect three-phase stator voltage , , And extract the components at specific frequencies (denoted as the characteristic frequencies). , , .

[0084] In some embodiments, healthy operation of the motor means that it is in rated operating conditions and a stable working environment.

[0085] S200 performs phase sequence analysis on the voltage characteristic spectrum components and current characteristic spectrum components to obtain positive sequence current, negative sequence current, positive sequence voltage, and negative sequence voltage.

[0086] In some embodiments, the formulas for calculating the positive-sequence current and the negative-sequence current are as follows:

[0087]

[0088] in, , , These are the current characteristic spectrum components of the three-phase stator current. , and The positive-sequence current and negative-sequence current of the target asynchronous motor in normal state;

[0089] The formulas for calculating positive-sequence voltage and negative-sequence voltage are as follows:

[0090]

[0091] in, , , These are the voltage characteristic spectrum components of the three-phase stator voltage. and The positive and negative sequence voltages of the target asynchronous motor represent its normal state, where the normal state indicates that the target asynchronous motor is in system debugging or motor healthy operation.

[0092] Similarly, when the target asynchronous motor is in a fault diagnosis state, the three-phase stator current of the asynchronous motor under test is collected. , , and three-phase stator voltage , , ; and perform spectral analysis to obtain the components whose frequencies are characteristic frequencies. , , and , , ;right , , Perform phase sequence analysis to calculate the three-phase stator positive sequence current. Negative sequence current ;right , , Perform phase sequence analysis to calculate the positive sequence voltage of the three-phase stator. Negative sequence voltage The calculation method is the same as when the target asynchronous motor is in a normal state, and will not be elaborated further.

[0093] S300, the target asynchronous motor is in normal condition, and the negative sequence admittance is determined by the quantitative relationship between the negative sequence current and the negative sequence voltage.

[0094] In some embodiments, the target asynchronous motor is in a normal state with negative sequence admittance. The calculation formula is:

[0095]

[0096] in, Indicates negative sequence current. This indicates the negative sequence voltage.

[0097] It should be noted that the process before and after calculating the negative-sequence admittance is the data acquisition and analysis process, while the process after calculating the positive and negative-sequence admittance is the fault diagnosis process.

[0098] In some embodiments, negative-order admittance The calculation, tuning, and retuning are as follows:

[0099] (1) When the target asynchronous motor is shipped from the factory or during initial commissioning, the negative sequence admittance is... During the tuning process, the target asynchronous motor is in fault diagnosis mode, maintaining negative sequence admittance. Understandably, when the target asynchronous motor is determined not to have a fault, the repeated fault diagnosis only needs to be performed after obtaining the negative sequence admittance, without the need to collect the three-phase stator current and three-phase stator voltage and calculate the negative sequence admittance.

[0100] (2) Obtain the load and environment during the operation of the target asynchronous motor. If the degree of change in load and environment is greater than the preset change value, then adjust the negative sequence admittance. Resetting involves dynamically adjusting the motor during operation. Y nn After the load conditions or working environment of the motor change to a certain extent, the negative sequence admittance will be affected. For example, after the system determines that no fault has occurred, if the motor load and working environment do not change significantly, only the fault diagnosis process is executed; if the motor load or working environment changes significantly, the data acquisition, analysis and fault diagnosis process needs to be executed.

[0101] The changes in load and (working) environment are determined based on preset change values. For example, the preset value for load is 0.5-0.9. When the load rate exceeds 0.9, it is considered a large load change. Similarly, the preset value for the ambient temperature of the motor is 40-85°. When it exceeds 85°, it is considered a large load change.

[0102] (3) Obtain the running time of the target asynchronous motor. When the running time is greater than the preset time, adjust the negative sequence admittance. Reconfigure.

[0103] In some embodiments, the adjustment is performed in real time during motor operation. Y nn By setting an adjustment time interval Δ T When the accumulated system runtime reaches Δ T Then, for negative-order admittance Perform a readjustment and restart the interval calculation. During fault diagnosis, if the system determines that no fault has occurred, and the accumulated motor running time has not reached Δ... T At that time, the repeated fault diagnosis process only includes the fault diagnosis process; when the accumulated running time of the motor reaches Δ T Afterwards, the diagnostic process needs to be repeated, including data acquisition, analysis, and fault diagnosis, and the interval time needs to be recalculated.

[0104] In some embodiments, such as Figure 4 As shown, it calculates the negative sequence admittance using the motor's nameplate parameters. Used to replace the collection and analysis steps During the tuning process, the motor's circuit parameters are obtained based on the parameters on the motor nameplate or the factory test parameters. It is a negative sequence impedance. The unit is imaginary; the nameplate data includes stator resistance. Leakage resistance Rotor resistance Leakage resistance Magnetizing Reactor and excitation resistor Negative-order admittance The calculation formula is:

[0105]

[0106]

[0107]

[0108] In some embodiments, the method further includes applying the average value method or the least squares method to the negative-order admittance. Perform the adjustment.

[0109] like Figure 5 As shown, this implementation is in Figure 4 Based on the illustrated embodiment, the positive and negative order transfer admittance matrix is... The setting calculation introduces disturbances to the grid voltage, and the data analysis module is described in [link to module]. Figure 2 In this embodiment, the fault diagnosis steps are repeated several times to measure the fault characteristics of the motor to be detected. The distribution pattern diagram, and its relationship with motor fault characteristics under healthy conditions. The comparison results of the distribution pattern diagrams are used as the basis for judgment. The specific operation steps are as follows:

[0110] (1) Under system debugging or motor healthy working conditions, collect several sets of signal data. Each set of signals includes the motor stator voltage. , , With stator current , , Furthermore, the negative sequence voltage components in each group of signals were obtained through spectrum analysis and phase sequence decomposition. With negative sequence current component ;

[0111] (2) Based on the negative sequence voltage in the collected multiple sets of signals With negative sequence current Negative-order admittance was calculated using linear regression. ,Right now:

[0112]

[0113] in and This represents the average of the negative sequence voltage component and the negative sequence current component across all sample data.

[0114] (3) Collect the three-phase stator current of the asynchronous motor to be tested. , , and three-phase stator voltage , , And extract the positive and negative sequence current and voltage components at specific frequencies. , , , ;

[0115] (4) Based on the positive and negative sequence currents and voltages in the collected multiple sets of signals , , , and negative order admittance Calculate the positive and negative order transfer admittances based on the quantitative relationship between them. ,Right now:

[0116]

[0117] Positive and negative order transit admittance As a fault characteristic, when When the value is within the safe zone, it is determined that no fault has occurred, and the system repeats the above fault diagnosis process; when it is outside the safe zone, it is determined that the motor has faulted, and according to... The amplitude and phase are used to determine the fault type.

[0118] The averaging method includes collecting sample data within a preset period and calculating the negative-order admittance of each sample data. Take the average of all data as the negative order admittance. The setpoint, calculated using the average value method, is as follows:

[0119]

[0120] in, For identifying the sequence of sampled data, The number of sample data represents and For the first k Negative sequence voltage and negative sequence current in the sample data. This is the setting value for the negative-order admittance. This represents the average value of the negative-sequence admittance. Specifically, during the initial commissioning of the motor, it is assumed that the motor is in a healthy state, and the negative-sequence voltage at the motor port is collected. With negative sequence current Based on negative sequence current and voltage and Calculate the negative sequence admittance of the asynchronous motor based on the quantitative relationships. .

[0121] The least squares method includes collecting sample data within a preset period and basing it on the negative sequence voltage. With negative sequence current Negative-order admittance using the least squares method The tuning is performed, and the calculation formula for the least squares method is as follows:

[0122]

[0123] in, and This represents the average of the negative-sequence voltage and negative-sequence current across all sample data. Specifically, in... Y nn During the tuning process, several voltage and current signal samples are collected in units of electrical cycles. Negative sequence voltage and negative sequence current are extracted and negative sequence admittance is calculated. Y nn Using each sample Y nn The average value is used as Y nn The set value.

[0124] S400, the target asynchronous motor is in fault diagnosis state. The positive and negative sequence transfer admittance is determined based on the quantitative relationship between negative sequence admittance, positive sequence current, negative sequence current, positive sequence voltage and negative sequence voltage.

[0125] In some embodiments, positive and negative order transfer admittance The calculation formula is:

[0126]

[0127] Among them, the positive sequence current, negative sequence current, positive sequence voltage, and negative sequence voltage of the target asynchronous motor in fault diagnosis state are: , , , ,and It is a negative-order admittance;

[0128] In some embodiments, the positive and negative order transfer admittances are calculated using the average value method or the least squares method. The averaging method includes collecting sample data within a preset period and calculating the positive and negative order admittance of each sample data. The average of all sample data is used as the positive and negative order admittance. The setpoint, calculated using the average value method, is as follows:

[0129]

[0130] in, For identifying the sequence of sampled data, For the number of sample data, , and This refers to the positive-sequence voltage, negative-sequence voltage, and positive-sequence current in the k-th group of sample data during fault diagnosis. This is the setting value for the positive and negative order admittances. It is the average of the positive and negative order admittances, specifically, in Y np During the measurement and calculation process, several voltage and current signal samples are collected in units of electrical cycles, and the positive and negative sequence transfer admittances are calculated respectively. Y np Using each sample Y np The average value is used as Y np The estimated value;

[0131] The least squares method involves collecting sample data within a preset period and then basing it on the negative sequence voltage. With negative sequence current Positive and negative order admittances using the least squares method The tuning is performed, and the calculation formula for the least squares method is as follows:

[0132]

[0133] in, and This represents the average of the negative-sequence voltage and negative-sequence current of all sample data in the fault diagnosis state. Specifically, in Y np During the measurement and calculation process, several voltage and current signal samples are collected in units of electrical cycles, and the least squares method and its derived mathematical methods are used to determine the positive and negative sequence transfer admittance. Perform tuning calculations. In some embodiments, during motor operation, simultaneously... Y nn and Y np Perform tuning calculations.

[0134] Figure 6 The illustrated embodiments also address Y nn and Y np The tuning calculation is performed using the least squares method, while simultaneously adjusting the negative-order admittance. Positive and negative sequence transit admittance The tuning calculation is performed using the following method:

[0135]

[0136] in:

[0137] ,

[0138] N This represents the total amount of data collected during the measurement period.

[0139] The above embodiments are all based on the principle of first... Perform tuning calculations, and then use measurement data to adjust... Perform calculations. For example... Figure 4 As shown, in this embodiment, and The tuning calculations are performed simultaneously.

[0140] (1) Collect three-phase stator current , , and three-phase stator voltage , , And extract the positive and negative sequence current and voltage components at specific frequencies. , , , ;

[0141] (2) Repeat the acquisition and analysis steps several times. Based on the acquired voltage and current data, the negative sequence admittance is simultaneously analyzed using the least squares method. Positive and negative sequence transit admittance Perform tuning calculations:

[0142]

[0143] in, , ,in N 2 represents the total amount of data collected during the measurement period. , , , They are respectively the i-th time (1≤ i ≤ N 2) The measured positive sequence voltage, negative sequence voltage, positive sequence current, and negative sequence current. Voltage matrix transpose, For matrix The inverse matrix.

[0144] Transmit admittance in positive and negative order As a fault characteristic, that is, based on the calculation The amplitude is used to determine whether the asynchronous motor has malfunctioned. When the value is within the safe zone, it is determined that no fault has occurred, and the system repeats the above fault diagnosis process; when it is outside the safe zone, it is determined that the motor has faulted, and according to... The amplitude and phase are used to determine the fault type.

[0145] S500 determines the fault diagnosis result of the target asynchronous motor based on the positive and negative sequence transfer admittance and the safe region, where the safe region is used to determine whether the target asynchronous motor is in a normal state or a fault diagnosis state.

[0146] In some embodiments, by determining whether the positive and negative sequence transfer admittances are in a safe region, if they are, the target asynchronous motor is in a healthy state; otherwise, the target asynchronous motor is in a fault state. If the target asynchronous motor is in a fault state, the fault type is determined based on the amplitude and phase coordinates of the positive and negative sequence admittances, and the fault diagnosis result is determined based on the fault type.

[0147] In some embodiments, Figure 7 This is the fault characteristic amplitude and phase distribution diagram of this embodiment. When the calculated positive and negative sequence transfer admittances are obtained... If the motor falls within the safe zone (i.e., zone one), then the motor is considered not faulty. When the calculated positive and negative sequence transfer admittance... If the vehicle lands outside the safe zone, the motor is deemed to have malfunctioned, and the cause is determined accordingly. The amplitude and phase coordinates are used to determine the fault type. Figure 7 Regions 2, 3, 4, and 5 correspond to open-circuit faults in parallel branches, abnormal phase-to-phase insulation faults, inter-turn short-circuit faults, and high-resistance connection faults, respectively. lie in Figure 7 If the motor fails to operate in an area other than Zones 1 to 5, it is determined that another abnormal fault has occurred within the motor.

[0148] In this embodiment, the value of Ω1 corresponding to the fault-free condition is... The values ​​of Ω2 to Ω5 corresponding to open circuit faults in parallel branches, abnormal phase-to-phase insulation faults, inter-turn short circuit faults, and high-resistance connection faults are as follows:

[0149]

[0150]

[0151]

[0152]

[0153] This embodiment eliminates the influence of nameplate parameter errors and changes in motor operating point on the results through dynamic parameter estimation, which is more adaptable to changes in motor operating status than the fixed parameter method; it actively introduces grid voltage disturbances to simulate actual grid fluctuation scenarios, improving the model's adaptability to unstable voltage conditions; it generates a fault feature distribution pattern by repeating measurements several times and compares the overlapping area with the healthy state distribution (threshold determination), avoiding single sampling errors, mitigating random noise interference, and enhancing the robustness of the results.

[0154] Figure 8 This is a graph showing the relationship between diagnostic coefficients, nameplate parameters, and motor operating points. Impedance parameters. and The accuracy of impedance settings depends on the actual operating conditions of the motor; directly using the nameplate parameters will lead to significant errors. Furthermore, in actual operation, motor operation is always affected by grid voltage fluctuations. Ideally, grid voltage fluctuations should not affect the sensitivity of impedance parameters to stator faults; however, in reality, the sensitivity of impedance parameters to stator faults is significantly affected. and The impedance setting contains errors, which are amplified by grid disturbances, thus significantly reducing the sensitivity of the impedance parameters to stator faults. Therefore, how to improve the impedance parameters... and The accuracy of the tuning algorithm is crucial for reducing the impact of operating point variations and grid disturbances on fault characteristics. Therefore, in one embodiment, the least squares method is used to... and Estimates are made to reduce the impact of operating point variations and grid disturbances on fault characteristics.

[0155] Figure 9 Fault characteristics before and after a fault in a single-turn short circuit example The distribution pattern is shown in the diagram. Its distribution clearly reflects the characteristics of the fault before and after the fault. The change proves the use of impedance parameters As a feasibility of fault characteristics, Figure 10 Fault characteristics before and after a parallel branch open circuit fault example The distribution pattern diagram shows that after a fault occurs... The amplitude increased significantly, showing a clear difference from before the fault, and the phase distribution was also relatively concentrated. Under different fault conditions, There are significant differences in the amplitude and phase distribution of the [significant difference]. Therefore, the health status of the motor can be diagnosed based on the changes in its amplitude and phase.

[0156] Figure 11This is a diagram of a motor stator winding fault diagnosis and analysis device according to an embodiment of the present invention. The device includes a first module 1110, a second module 1120, a third module 1130, a fourth module 1140, and a fifth module 1150.

[0157] The system comprises five modules: The first module collects the three-phase stator current and three-phase stator voltage of the target asynchronous motor in normal operation, performs spectral analysis on the three-phase stator current and three-phase stator voltage to obtain voltage characteristic spectral components and current characteristic spectral components; the second module performs phase sequence analysis on the voltage characteristic spectral components and current characteristic spectral components to obtain positive-sequence current, negative-sequence current, positive-sequence voltage, and negative-sequence voltage; the third module determines the negative-sequence admittance based on the quantitative relationship between negative-sequence current and negative-sequence voltage when the target asynchronous motor is in normal operation; the fourth module determines the positive and negative-sequence transfer admittance based on the quantitative relationship between negative-sequence admittance, positive-sequence current, negative-sequence current, positive-sequence voltage, and negative-sequence voltage when the target asynchronous motor is in fault diagnosis mode; and the fifth module determines the fault diagnosis result of the target asynchronous motor based on the positive and negative-sequence transfer admittance and the safe region, where the safe region is used to determine whether the target asynchronous motor is in normal operation or fault diagnosis mode.

[0158] For example, with the cooperation of the first to fifth modules in the device, the embodiment device can implement any of the aforementioned motor stator winding fault diagnosis methods, namely, collecting the three-phase stator current and three-phase stator voltage of the target asynchronous motor in a normal state, performing spectrum analysis on the three-phase stator current and three-phase stator voltage to obtain voltage characteristic spectrum components and current characteristic spectrum components; performing phase sequence analysis on the voltage characteristic spectrum components and current characteristic spectrum components to obtain positive sequence current, negative sequence current, positive sequence voltage, and negative sequence voltage; when the target asynchronous motor is in a normal state, determining the negative sequence admittance through the quantitative relationship between the negative sequence current and negative sequence voltage; when the target asynchronous motor is in a fault diagnosis state, determining the positive and negative sequence transfer admittance based on the quantitative relationship between the negative sequence admittance, positive sequence current, negative sequence current, positive sequence voltage, and negative sequence voltage; and determining the fault diagnosis result of the target asynchronous motor based on the positive and negative sequence transfer admittance and the safe region, wherein the safe region is used to determine whether the target asynchronous motor is in a normal state or a fault diagnosis state. The beneficial effects of this invention are as follows: It employs a non-invasive design, requiring only the acquisition of motor voltage and current signals for real-time monitoring without affecting normal equipment operation; the diagnostic process uses only parameters such as voltage and current, directly reusing existing electrical parameter ports without the need for vibration or temperature sensors, significantly reducing diagnostic costs; it identifies a wide range of fault types, using dual diagnosis of characteristic impedance amplitude and phase to identify various faults such as inter-turn short circuits, phase-to-phase insulation abnormalities, open circuits in parallel branches, and high-resistance connections; it uses dynamic parameter estimation and anti-interference algorithms to eliminate the influence of nameplate parameter errors and changes in motor operating points on the results, improving the model's adaptability to unstable voltage conditions and demonstrating good robustness; the calculation is simple, the setting time is short, and it allows for long-term continuous online monitoring.

[0159] This invention also provides an electronic device, which includes a processor and a memory;

[0160] The memory stores the program;

[0161] The processor executes a program to perform the aforementioned method for diagnosing motor stator winding faults; the electronic device has the function of carrying and running the software system for diagnosing motor stator winding faults provided in the embodiments of the present invention, such as a personal computer, minicomputer, mainframe, workstation, network or distributed computing environment, standalone or integrated computer platform, or communicating with charged particle tools or other imaging devices, etc.

[0162] This invention also provides a computer-readable storage medium storing a program that is executed by a processor to implement the motor stator winding fault diagnosis method described above.

[0163] In some alternative embodiments, the functions / operations mentioned in the block diagrams may not occur in the order shown in the operation diagrams. For example, depending on the functions / operations involved, two consecutively shown blocks may actually be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order. Furthermore, the embodiments presented and described in the flowcharts of this invention are provided by way of example to provide a more comprehensive understanding of the technology. The disclosed methods are not limited to the operations and logic flows presented herein. Alternative embodiments are contemplated in which the order of various operations is altered and sub-operations described as part of a larger operation are executed independently.

[0164] This invention also discloses a computer program product or computer program, which includes computer instructions stored in a computer-readable storage medium. A processor of a computer device can read the computer instructions from the computer-readable storage medium and execute the computer instructions, causing the computer device to perform the aforementioned motor stator winding fault diagnosis method.

[0165] Furthermore, although the invention has been described in the context of functional modules, it should be understood that, unless otherwise stated, one or more of the described functions and / or features may be integrated into a single physical device and / or software module, or one or more functions and / or features may be implemented in a separate physical device or software module. It is also understood that a detailed discussion of the actual implementation of each module is unnecessary for understanding the invention. Rather, given the properties, functions, and internal relationships of the various functional modules in the apparatus disclosed herein, the actual implementation of the module will be understood within the scope of conventional skill of an engineer. Therefore, those skilled in the art can implement the invention as set forth in the claims using ordinary techniques without excessive experimentation. It is also understood that the specific concepts disclosed are merely illustrative and not intended to limit the scope of the invention, which is determined by the full scope of the appended claims and their equivalents.

[0166] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion 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 this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0167] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-including system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device.

[0168] More specific examples of computer-readable media (a non-exhaustive list) include: electrical connections (electronic devices) having one or more wires, portable computer disk drives (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, computer-readable media can even be paper or other suitable media on which the program can be printed, because the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in computer memory.

[0169] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0170] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0171] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

[0172] The above is a detailed description of the preferred embodiments of the present invention, but the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A method for diagnosing faults in the stator winding of an electric motor, characterized in that, include: The three-phase stator current and three-phase stator voltage of the target asynchronous motor under normal conditions are collected, and the three-phase stator current and three-phase stator voltage are subjected to spectrum analysis to obtain the voltage characteristic spectrum components and the current characteristic spectrum components. Phase sequence analysis is performed on the voltage characteristic spectrum components and the current characteristic spectrum components to obtain the positive sequence current, negative sequence current, positive sequence voltage, and negative sequence voltage. The target asynchronous motor is in normal condition. The negative sequence admittance is determined by the quantitative relationship between the negative sequence current and the negative sequence voltage. The target asynchronous motor is in a fault diagnosis state. The positive and negative sequence transfer admittance is determined based on the quantitative relationship between negative sequence admittance, positive sequence current, negative sequence current, positive sequence voltage, and negative sequence voltage. The fault diagnosis result of the target asynchronous motor is determined based on the positive and negative sequence transfer admittance and the safe region, where the safe region is used to determine whether the target asynchronous motor is in a normal state or a fault diagnosis state. The phase sequence analysis of the voltage characteristic spectrum components and current characteristic spectrum components to obtain positive sequence current, negative sequence current, positive sequence voltage, and negative sequence voltage includes: The formulas for calculating the positive-sequence current and the negative-sequence current are as follows: ； in, , , These are the current characteristic spectrum components of the three-phase stator current. , , and The positive sequence current, negative sequence current, and zero sequence current of the target asynchronous motor in normal state; The formulas for calculating the positive-sequence voltage and the negative-sequence voltage are as follows: ； in, , , These are the voltage characteristic spectrum components of the three-phase stator voltage. , and The positive sequence voltage, negative sequence voltage, and zero sequence voltage of the target asynchronous motor in normal state indicate that the target asynchronous motor is in system debugging or motor healthy operation. The target asynchronous motor is in a normal state. The negative sequence admittance is determined by the quantitative relationship between the negative sequence current and the negative sequence voltage, including: Negative-order admittance The calculation formula is: ； in, Indicates negative sequence current. Indicates negative sequence voltage; And, when the target asynchronous motor is shipped from the factory or undergoes initial commissioning, the negative sequence admittance... During the tuning process, the target asynchronous motor is in fault diagnosis mode, maintaining negative sequence admittance. constant; or Obtain the load and environment conditions during the operation of the target asynchronous motor. If the degree of change in load and environment exceeds a preset change value, adjust the negative sequence admittance. Perform a reconfiguration; or Obtain the running time of the target asynchronous motor. When the running time exceeds a preset time, adjust the negative sequence admittance. Reconfigure.

2. The method for diagnosing faults in motor stator windings according to claim 1, characterized in that, The method further includes: Obtain the nameplate data of the target asynchronous motor, and perform negative-sequence admittance based on the nameplate data. The formula for setting or resetting is: ； in It is a negative sequence impedance. The unit is imaginary; the nameplate data includes stator resistance. Leakage resistance Rotor resistance Leakage resistance Magnetizing Reactor and excitation resistor .

3. The method for diagnosing faults in motor stator windings according to claim 1, characterized in that, The method further includes: Negative-order admittance can be determined using the average value method or the least squares method. Perform the adjustment; The averaging method includes collecting sample data within a preset period and calculating the negative order admittance of each sample data. Take the average of all data as the negative order admittance. The setpoint, calculated using the average value method, is as follows: ； in, For identifying the sequence of sampled data, For the number of sample data, and For the first k Negative sequence voltage and negative sequence current in the sample data. This is the setting value for the negative-order admittance. It is the average value of the negative-order admittance; The least squares method includes collecting sample data within a preset period, and based on the negative sequence voltage... With negative sequence current Negative-order admittance using the least squares method The tuning is performed, and the calculation formula for the least squares method is as follows: ； in, and These represent the average negative-sequence voltage and the average negative-sequence current of the sample data.

4. The method for diagnosing faults in motor stator windings according to claim 1, characterized in that, The target asynchronous motor is in a fault diagnosis state. The positive and negative sequence transfer admittances are determined based on the quantitative relationship between negative sequence admittance, positive sequence current, negative sequence current, positive sequence voltage, and negative sequence voltage, including: Positive and negative sequence transit admittance The calculation formula is: ； Among them, the positive sequence current, negative sequence current, positive sequence voltage, and negative sequence voltage of the target asynchronous motor in fault diagnosis state are: , , and , It is a negative-order admittance; Furthermore, the positive and negative order transfer admittances are calculated using the average value method or the least squares method. ; The averaging method includes collecting sample data within a preset period and calculating the positive and negative order admittance of each sample data. The average of all sample data is used as the positive and negative order admittance. The setpoint, calculated using the average value method, is as follows: ； in, For identifying the sequence of sampled data, For the number of sample data, , and This refers to the positive-sequence voltage, negative-sequence voltage, and positive-sequence current in the k-th group of sample data during fault diagnosis. This is the setting value for the positive and negative order admittances. It is the average of the positive and negative order admittances; The least squares method includes collecting sample data within a preset period, and based on the negative sequence voltage... With negative sequence current For positive and negative order admittance The tuning is performed, and the calculation formula for the least squares method is as follows: ； in, and The average negative sequence voltage and average negative sequence current of the sample data.

5. The method for diagnosing faults in motor stator windings according to claim 1, characterized in that, The fault diagnosis results of the target asynchronous motor determined based on the positive and negative sequence transfer admittance and the safe region include: Determine whether the positive and negative sequence transfer admittances are within the safe region. If they are, the target asynchronous motor is in a healthy state; otherwise, the target asynchronous motor is in a fault state. The target asynchronous motor is in a fault state. The fault type is determined based on the magnitude and phase coordinates of the positive and negative sequence admittances, and the fault diagnosis result is determined based on the fault type.

6. A fault diagnosis device for motor stator windings, characterized in that, include: The first module is used to collect the three-phase stator current and three-phase stator voltage of the target asynchronous motor in normal condition, and to perform spectrum analysis on the three-phase stator current and three-phase stator voltage to obtain the voltage characteristic spectrum components and the current characteristic spectrum components. The second module is used to perform phase sequence analysis on the voltage characteristic spectrum components and the current characteristic spectrum components to obtain positive sequence current, negative sequence current, positive sequence voltage and negative sequence voltage. The third module is used to determine the negative sequence admittance by the quantitative relationship between the negative sequence current and the negative sequence voltage when the target asynchronous motor is in normal state. The fourth module is used to determine the positive and negative sequence transfer admittance based on the quantitative relationship between negative sequence admittance, positive sequence current, negative sequence current, positive sequence voltage, and negative sequence voltage when the target asynchronous motor is in a fault diagnosis state. The fifth module is used to determine the fault diagnosis result of the target asynchronous motor based on the positive and negative sequence of the transmit admittance and the safe region, wherein the safe region is used to determine whether the target asynchronous motor is in a normal state or a fault diagnosis state. The phase sequence analysis of the voltage characteristic spectrum components and current characteristic spectrum components to obtain positive sequence current, negative sequence current, positive sequence voltage, and negative sequence voltage includes: The formulas for calculating the positive-sequence current and the negative-sequence current are as follows: ； in, , , These are the current characteristic spectrum components of the three-phase stator current. , , and The positive sequence current, negative sequence current, and zero sequence current of the target asynchronous motor in normal state; The formulas for calculating the positive-sequence voltage and the negative-sequence voltage are as follows: ； in, , , These are the voltage characteristic spectrum components of the three-phase stator voltage. , and The positive sequence voltage, negative sequence voltage, and zero sequence voltage of the target asynchronous motor in normal state indicate that the target asynchronous motor is in system debugging or motor healthy operation. The target asynchronous motor is in a normal state. The negative sequence admittance is determined by the quantitative relationship between the negative sequence current and the negative sequence voltage, including: Negative-order admittance The calculation formula is: ； in, Indicates negative sequence current. Indicates negative sequence voltage; And, when the target asynchronous motor is shipped from the factory or undergoes initial commissioning, the negative sequence admittance... During the tuning process, the target asynchronous motor is in fault diagnosis mode, maintaining negative sequence admittance. constant; or Obtain the load and environment conditions during the operation of the target asynchronous motor. If the degree of change in load and environment exceeds a preset change value, adjust the negative sequence admittance. Perform a reconfiguration; or Obtain the running time of the target asynchronous motor. When the running time exceeds a preset time, adjust the negative sequence admittance. Reconfigure.

7. An electronic device, characterized in that, Including the processor and memory; The memory is used to store programs; The processor executes the program to implement the motor stator winding fault diagnosis method as described in any one of claims 1-5.

8. A computer-readable storage medium, characterized in that, The storage medium stores a program, which is executed by a processor to implement the motor stator winding fault diagnosis method as described in any one of claims 1-5.

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