A method for detecting outer raceway failure of rolling bearing of three-phase asynchronous motor
By collecting stator current signals and constructing an external raceway fault map, the problem of stable detection and accurate identification of rolling bearing external raceway faults under complex operating conditions in new energy vehicles was solved. Stable extraction and prediction of fault features were achieved, improving the accuracy and reliability of fault identification and expansion trend analysis.
Patent Information
- Application Number
- CN202611210816.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-08-11
- Publication Date
- 2026-11-06
AI Technical Summary
Existing fault detection technologies for the outer raceway of rolling bearings in three-phase asynchronous motors cannot achieve stable extraction and accurate identification of early fault characteristics under the complex and variable operating conditions and remote operation and maintenance conditions of new energy vehicles. Especially under frequent start-stop, rapid speed change and high-frequency PWM drive environments, traditional detection methods are difficult to extract fault information, and remote diagnosis is limited by bandwidth and computing resources.
By collecting stator current signals to estimate the instantaneous rotor speed, constructing a rotation analysis segment for local equal-angle resampling, extracting abnormal impact features, and combining vehicle operating conditions to analyze the abnormal impact angle migration trajectory, an outer raceway fault map is established to predict the fault expansion trend and generate early warning results.
It achieves stable extraction of external raceway fault impact characteristics under variable speed conditions, improves fault identification accuracy and expansion trend analysis capability, reduces the impact of short-term disturbances on fault maps, and enhances the stability and reliability of prediction results.
Smart Images
Figure CN123045720A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of drive motor fault detection technology, and in particular relates to a method for detecting faults in the outer raceway of rolling bearings in a three-phase asynchronous motor. Background Technology
[0002] With the rapid development of plug-in hybrid electric vehicles, pure electric vehicles, and fuel cell vehicles, three-phase asynchronous drive motors are widely used in the electric drive systems of new energy vehicles due to their reliable structure, low cost, and strong adaptability to complex working conditions. As a key supporting component in the drive motor, the operating status of rolling bearings directly affects the stability of the electric drive system and the safety of the vehicle operation. Therefore, it is necessary to detect rolling bearing outer raceway faults in real time and accurately to meet the needs of remote operation and maintenance and predictive maintenance of new energy vehicles.
[0003] Current methods for detecting outer raceway faults in rolling bearings of three-phase asynchronous motors typically involve vibration signal acquisition, spectrum analysis, envelope demodulation, or characteristic frequency extraction to identify the fault. Some technologies also combine current or temperature signals for comprehensive diagnosis. However, new energy vehicle drive motors operate under conditions of frequent start-stop, rapid speed changes, regenerative braking, and high-frequency PWM drive, resulting in significant unsteady changes in motor speed and load, causing the characteristic frequency of bearing outer raceway faults to drift. Simultaneously, high-frequency electromagnetic noise and multi-source coupled vibrations generated by the inverter can mask early, weak fault characteristics, making it difficult for traditional fixed spectrum analysis-based detection methods to reliably extract fault information. Furthermore, in remote maintenance scenarios for new energy vehicles, the limited bandwidth of the vehicle network and onboard computing resources prevent the long-term uploading of large amounts of raw vibration data, further reducing the accuracy and real-time performance of remote fault diagnosis.
[0004] Existing technologies for detecting external raceway faults in rolling bearings of three-phase asynchronous motors are unable to achieve stable extraction and accurate identification of early fault characteristics of the external raceway under the complex and variable operating conditions of new energy vehicles and remote operation and maintenance conditions. Therefore, this invention proposes a method for detecting external raceway faults in rolling bearings of three-phase asynchronous motors. Summary of the Invention
[0005] The purpose of this invention is to provide a method for detecting external raceway faults in rolling bearings of three-phase asynchronous motors, which solves the problem that existing external raceway fault detection technologies for rolling bearings of three-phase asynchronous motors cannot achieve stable extraction and accurate identification of early fault characteristics of the external raceway under complex and variable operating conditions and remote operation and maintenance conditions of new energy vehicles.
[0006] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution: This invention relates to a method for detecting faults in the outer raceway of rolling bearings in a three-phase asynchronous motor, comprising the following steps: S1. Collect the stator current signal during the operation of the three-phase asynchronous motor, and estimate the instantaneous speed of the rotor of the three-phase asynchronous motor based on the stator current signal; S2. Construct multiple rotational analysis segments based on preset reference angles. Each rotational analysis segment starts from the corresponding reference angle and ends after the three-phase asynchronous motor rotates a preset number of times. Combined with the instantaneous speed within the corresponding time period, perform local equal-angle resampling on the stator current signal in each rotational analysis segment to obtain the angle domain fault impact signal within the corresponding time period. S3. Extract abnormal impact features from the angle domain fault impact signals corresponding to each time period to obtain the angle distribution location corresponding to the abnormal impact. S4. Compare the consistency of abnormal impact angle distribution in different time periods. When abnormal impacts in multiple time periods continuously appear in the same angle region, it is determined that there is a fixed outer raceway defect in the corresponding angle region. When the location of abnormal impact angle distribution migrates or expands, it is determined that the outer raceway defect is in an expanding evolution state. S5. Construct the abnormal impact angle migration trajectory based on the abnormal impact angle distribution location in different time periods, and analyze the correlation between abnormal impact and vehicle operating conditions in combination with vehicle operating condition information, so as to identify the operating condition triggering factors that induce the evolution of outer raceway defects. S6. Establish an outer raceway fault map based on the abnormal impact angle migration trajectory. The outer raceway fault map is used to record the angle distribution area, migration direction and corresponding working condition information of abnormal impact in different time periods. Based on the outer raceway fault map, predict the target angle area of the next abnormal impact and the expansion trend of outer raceway defects. S7. Generate early warning results for outer raceway faults based on the predicted target angle region.
[0007] Furthermore, the step S1 of estimating the instantaneous speed of the three-phase asynchronous motor rotor based on the stator current signal includes the following specific details: S1.1 Perform high-frequency noise suppression processing on the acquired three-phase stator current signal to filter out high-frequency interference components corresponding to the inverter PWM switching frequency; S1.2. Lock the fundamental frequency of the noise-suppressed three-phase stator current signal to obtain the motor synchronization frequency; S1.3 Calculate the instantaneous mechanical speed of the rotor by combining the real-time operating voltage and current amplitude of the motor and the motor slip rate, and generate the corresponding instantaneous speed change curve.
[0008] Furthermore, in step S2, each rotation analysis segment starts at a preset reference angle and ends after the motor rotates a preset number of times. The rotation angle corresponding to each sampling moment is calculated based on the instantaneous speed change curve within the corresponding time period. The stator current sampling points in the time domain are remapped to the angle domain coordinates corresponding to the fixed angle interval to form a local equal-angle resampling sequence within the corresponding time period.
[0009] Furthermore, the abnormal impact feature extraction of the angle domain fault impact signal in step S3 includes the following specific contents: S3.1 Perform Hilbert transform on the angle domain fault impact signal to obtain the envelope signal; S3.2 Perform order spectrum analysis on the envelope signal to extract the spectral energy corresponding to the order of the outer raceway fault characteristics; S3.3 Determine the angular distribution location and impact intensity corresponding to the abnormal impact based on the changes in spectral line amplitude.
[0010] Furthermore, the comparison of the consistency of the abnormal impact angle distribution locations in different time periods in step S4 includes the following: S4.1 Calculate the angular offset of the abnormal impact center and the angular range of the abnormal impact coverage in adjacent time periods; S4.2 When the abnormal impact center angle offset is less than the preset offset threshold in multiple consecutive time periods, the corresponding abnormal impact is determined to be a fixed outer raceway defect. S4.3 When the abnormal impact center angle offset continues to increase and the coverage angle range expands synchronously, it is determined that the corresponding outer raceway defect is in an expansion evolution state.
[0011] Furthermore, in step S5, when constructing the abnormal impact angle migration trajectory, the abnormal impact center angle, impact intensity, and impact coverage of each time period are recorded in chronological order to form an abnormal impact angle time series. The correspondence between the abnormal impact angle migration speed and the vehicle driving torque, regenerative braking state, and vehicle driving section is analyzed in combination with vehicle operating condition information to identify the operating condition triggering factors that induce the expansion of the outer rolling track defect. The step S6 of establishing the outer raceway fault map includes: constructing an angle heat matrix based on the distribution area of abnormal impact angles in different time periods; generating the fault risk level of the corresponding angle area based on the frequency of occurrence and impact intensity of abnormal impacts in each angle area; generating an outer raceway defect expansion path map based on the migration direction of abnormal impact angles; and predicting the target angle area of the next abnormal impact based on the outer raceway defect expansion path map.
[0012] Furthermore, the generation of the outer raceway fault warning result based on the predicted target angle region in S7 includes the following specific contents: S7.1 Improve the signal sampling frequency and abnormal impact detection sensitivity within the corresponding time period of the target angle area; S7.2 Calculate the abnormal impact growth rate in the target angle region; S7.3 When the abnormal impact growth rate continuously exceeds the preset growth threshold, generate the corresponding level of outer raceway fault warning information.
[0013] Furthermore, the analysis of the correspondence between the abnormal impact angle migration speed and the vehicle operating conditions includes: obtaining the direction of change of driving torque, the magnitude of change of motor load, and the longitudinal acceleration of the vehicle under different operating conditions; determining the main action direction of the rolling bearing load based on the direction of change of driving torque, and calculating the coupling relationship between the defect propagation direction and the main action direction of the load in combination with the abnormal impact angle migration direction; when the abnormal impact angle migration direction and the main action direction of the load are continuously consistent, and the abnormal impact migration speed continuously increases with the increase of driving torque, it is determined that the corresponding operating condition has a promoting effect on the propagation of defects in the outer raceway, and the risk weight of the corresponding operating condition in the outer raceway fault map is increased.
[0014] Furthermore, the step of establishing an outer raceway fault map and predicting the target angle region of the next abnormal impact includes: continuously analyzing the angle offset of abnormal impacts in different time periods; when the angle offset of an abnormal impact only occurs during a short-term change in operating conditions and the corresponding abnormal impact does not recur in subsequent time periods, the corresponding abnormal impact is determined to be a transient offset impact; the risk weight of the transient offset impact in the outer raceway fault map is reduced, and the risk coverage of the corresponding angle region is narrowed; the risk weight of the abnormal impact angle migration trajectory that recurs in multiple consecutive time periods is increased to construct a continuously updated dynamic fault map, and the target angle region of the next abnormal impact and the direction of outer raceway defect expansion are predicted based on the updated dynamic fault map.
[0015] Furthermore, the construction of the continuously updated dynamic fault map includes: continuously statistically analyzing the migration directions of abnormal impact angles in different time periods, calculating the recurrence frequency and duration corresponding to each migration direction; determining the migration direction with a recurrence frequency consistently higher than a preset stable threshold as the main migration direction; suppressing transient angle jumps that deviate from the main migration direction and reducing the influence weight of the corresponding abnormal impact on the update results of the outer raceway fault map; constructing a stable evolutionary main trajectory of the outer raceway defect based on the main migration direction, and predicting the subsequent expansion path and risk growth trend of the outer raceway defect based on the stable evolutionary main trajectory.
[0016] The present invention has the following beneficial effects: 1. This invention achieves stable extraction of outer raceway fault impact characteristics under variable speed conditions by constructing a local equal-angle resampling sequence based on stator current signals and combining it with the consistency analysis of abnormal impact angle distribution. At the same time, by constructing an abnormal impact angle migration trajectory and combining it with the analysis of vehicle operating conditions to understand the outer raceway defect expansion behavior, this invention improves the accuracy of outer raceway fault identification and the ability to analyze fault expansion trends under complex dynamic conditions of new energy vehicles.
[0017] 2. This invention continuously analyzes the abnormal impact angle offsets in different time periods to identify transient offset impacts and reduce the risk weight of the corresponding abnormal impacts in the outer raceway fault map, thereby reducing the impact of short-term random disturbances on the fault map update results. Furthermore, by increasing the risk weight corresponding to the continuously recurring abnormal impact angle migration trajectory, it improves the ability of the outer raceway fault map to represent long-term stable defect expansion behavior and enhances the stability of the outer raceway defect expansion direction prediction results.
[0018] 3. This invention determines the main migration direction of the outer raceway defect by continuously statistically analyzing the migration direction of abnormal impact angles in different time periods, and constructs a stable evolutionary main trajectory based on the main migration direction, thereby reducing the jump in fault map direction caused by short-term operating disturbances; and improves the continuity and reliability of the analysis results of the long-term evolution behavior of the outer raceway defect by predicting the subsequent expansion path and risk growth trend of the outer raceway defect based on the stable evolutionary main trajectory. Attached Figure Description
[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0020] Figure 1 This is a flowchart of the method of the present invention. Detailed Implementation
[0021] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments. Example 1
[0022] See Figure 1 This invention relates to a method for detecting faults in the outer raceway of a rolling bearing in a three-phase asynchronous motor, comprising the following steps: S1. Collect the stator current signal during the operation of the three-phase asynchronous motor, and estimate the instantaneous speed of the rotor of the three-phase asynchronous motor based on the stator current signal; It should be further explained that the stator current signal is acquired in real time by the current sampling module in the motor controller and continuously sampled according to the preset sampling frequency; in the high-frequency noise suppression process, a notch suppression band corresponding to the inverter PWM switching frequency is constructed to reduce the impact of the inverter's high-frequency switching action on the subsequent fault impact extraction results; the instantaneous speed change curve is used to reflect the real-time speed fluctuation state of the three-phase asynchronous motor under dynamic operating conditions, so as to improve the accuracy of the angle mapping results in the subsequent local equal-angle resampling process.
[0023] The step S1, which estimates the instantaneous speed of the three-phase asynchronous motor rotor based on the stator current signal, includes the following specific details: S1.1 Perform high-frequency noise suppression processing on the acquired three-phase stator current signal to filter out high-frequency interference components corresponding to the inverter PWM switching frequency; S1.2. Lock the fundamental frequency of the noise-suppressed three-phase stator current signal to obtain the motor synchronization frequency; S1.3 Calculate the instantaneous mechanical speed of the rotor by combining the real-time operating voltage and current amplitude of the motor and the motor slip rate, and generate the corresponding instantaneous speed change curve.
[0024] S2. Construct multiple rotational analysis segments based on preset reference angles. Each rotational analysis segment starts from the corresponding reference angle and ends after the three-phase asynchronous motor rotates a preset number of times. Combined with the instantaneous speed within the corresponding time period, perform local equal-angle resampling on the stator current signal in each rotational analysis segment to obtain the angle domain fault impact signal within the corresponding time period. It should be further explained that the rotation analysis segments are constructed continuously in chronological order, and adjacent rotation analysis segments are continuously connected. During the local equal-angle resampling process, the cumulative rotation angle corresponding to each sampling moment is calculated through the instantaneous rotation speed change curve, and the angle domain sampling sequence is regenerated according to the fixed angle interval to eliminate the change in fault impact time interval caused by rotation speed fluctuation. After the local equal-angle resampling process, the fault impacts in different time periods form a stable correspondence in the angle domain, thereby improving the stability of the subsequent abnormal impact angle consistency analysis results.
[0025] In step S2, each rotation analysis segment starts at a preset reference angle and ends after the motor rotates a preset number of times. The rotation angle corresponding to each sampling moment is calculated based on the instantaneous speed change curve within the corresponding time period. The stator current sampling points in the time domain are remapped to the angle domain coordinates corresponding to the fixed angle interval to form a local equal-angle resampling sequence within the corresponding time period.
[0026] S3. Extract abnormal impact features from the angle domain fault impact signals corresponding to each time period to obtain the angle distribution location corresponding to the abnormal impact. It should be further explained that, in the process of extracting abnormal impact features, the envelope enhancement processing of the angle domain fault impact signal is performed to improve the separability between weak impact signals and background noise; the order spectrum analysis is used to extract the impact energy change corresponding to the order of the outer raceway fault features to enhance the identification ability of early weak fault features of the outer raceway defect; the angle distribution position corresponding to the abnormal impact is used to characterize the spatial distribution state of the outer raceway defect in the angle domain.
[0027] Step S3, which involves extracting abnormal impact features from the angle-domain fault impact signal, includes the following specific steps: S3.1 Perform Hilbert transform on the angle domain fault impact signal to obtain the envelope signal; S3.2 Perform order spectrum analysis on the envelope signal to extract the spectral energy corresponding to the order of the outer raceway fault characteristics; S3.3 Determine the angular distribution location and impact intensity corresponding to the abnormal impact based on the changes in spectral line amplitude.
[0028] S4. Compare the consistency of abnormal impact angle distribution in different time periods. When abnormal impacts in multiple time periods continuously appear in the same angle region, it is determined that there is a fixed outer raceway defect in the corresponding angle region. When the location of abnormal impact angle distribution migrates or expands, it is determined that the outer raceway defect is in an expanding evolution state. It should be further explained that the consistency of the abnormal impact angle distribution is used to characterize the spatial stability of the outer raceway defect over multiple time periods. When the abnormal impact occurs stably in the same angle region for a long period of time, it indicates that the rolling element continuously passes through the fixed defect position. When the coverage angle range of the abnormal impact continues to expand, it indicates that the contact area of the outer raceway defect is gradually expanding. By jointly analyzing the center angle offset of the abnormal impact and the coverage angle range, the fixed state and the expanded state of the outer raceway defect can be distinguished and identified.
[0029] The step S4, comparing the consistency of the abnormal impact angle distribution locations across different time periods, includes the following: S4.1 Calculate the angular offset of the abnormal impact center and the angular range of the abnormal impact coverage in adjacent time periods; S4.2 When the abnormal impact center angle offset is less than the preset offset threshold in multiple consecutive time periods, the corresponding abnormal impact is determined to be a fixed outer raceway defect. S4.3 When the abnormal impact center angle offset continues to increase and the coverage angle range expands synchronously, it is determined that the corresponding outer raceway defect is in an expansion evolution state.
[0030] S5. Construct the abnormal impact angle migration trajectory based on the abnormal impact angle distribution location in different time periods, and analyze the correlation between abnormal impact and vehicle operating conditions in combination with vehicle operating condition information, so as to identify the operating condition triggering factors that induce the evolution of outer raceway defects. It should be further explained that the abnormal impact angle migration trajectory is used to reflect the expansion direction and trend of the outer rolling track defect in the time dimension; the vehicle operating condition information includes the vehicle driving state, driving torque change state, regenerative braking state, and vehicle dynamic load change state; by analyzing the correspondence between the abnormal impact angle migration direction and the vehicle operating condition, the key operating condition factors that lead to the accelerated expansion of the outer rolling track defect are identified, so as to improve the accuracy of the outer rolling track fault expansion trend analysis results.
[0031] In step S5, when constructing the abnormal impact angle migration trajectory, the abnormal impact center angle, impact intensity, and impact coverage of each time period are recorded in chronological order to form an abnormal impact angle time series. The correspondence between the abnormal impact angle migration speed and the vehicle driving torque, regenerative braking state, and vehicle driving section is analyzed in combination with vehicle operating condition information to identify the operating condition triggering factors that induce the expansion of the outer rolling track defect.
[0032] S6. Establish an outer raceway fault map based on the abnormal impact angle migration trajectory. The outer raceway fault map is used to record the angle distribution area, migration direction and corresponding working condition information of abnormal impact in different time periods. Based on the outer raceway fault map, predict the target angle area of the next abnormal impact and the expansion trend of outer raceway defects. It should be further explained that the outer raceway fault map is continuously updated by the distribution area of abnormal impact angles in different time periods to form a dynamic distribution model of outer raceway defects in the angle domain; the angle heat matrix is used to reflect the degree of abnormal impact aggregation in different angle regions; the fault risk level is used to characterize the degree of deterioration of outer raceway defects in the corresponding angle region; and the migration direction of abnormal impacts is continuously tracked by the outer raceway defect expansion path map to achieve predictive analysis of the subsequent expansion area of outer raceway defects.
[0033] The step S6 of establishing the outer raceway fault map includes: constructing an angle heat matrix based on the distribution area of abnormal impact angles in different time periods; generating the fault risk level of the corresponding angle area based on the frequency of occurrence and impact intensity of abnormal impacts in each angle area; generating an outer raceway defect expansion path map based on the migration direction of abnormal impact angles; and predicting the target angle area of the next abnormal impact based on the outer raceway defect expansion path map.
[0034] S7. Generate early warning results for outer raceway faults based on the predicted target angle region.
[0035] It should be further explained that the target angle region corresponds to the angle range where the subsequent expansion probability of the outer raceway defect is relatively high; by increasing the signal sampling frequency and abnormal impact detection sensitivity within the time period corresponding to the target angle region, the fault impact capture capability in the subsequent expansion stage of the outer raceway defect is improved; the outer raceway fault early warning result is used to reflect the current expansion status of the outer raceway defect and the subsequent risk growth trend.
[0036] The outer raceway fault early warning result generated in S7 based on the predicted target angle region includes the following specific contents: S7.1 Improve the signal sampling frequency and abnormal impact detection sensitivity within the corresponding time period of the target angle area; S7.2 Calculate the abnormal impact growth rate in the target angle region; S7.3 When the abnormal impact growth rate continuously exceeds the preset growth threshold, generate the corresponding level of outer raceway fault warning information.
[0037] The analysis of the correspondence between the abnormal impact angle migration speed and the vehicle operating conditions includes: obtaining the direction of change of driving torque, the magnitude of change of motor load, and the longitudinal acceleration of the vehicle under different operating conditions; determining the main action direction of the rolling bearing load based on the direction of change of driving torque, and calculating the coupling relationship between the defect propagation direction and the main action direction of the load in combination with the abnormal impact angle migration direction; when the abnormal impact angle migration direction and the main action direction of the load are continuously consistent, and the abnormal impact migration speed continuously increases with the increase of driving torque, it is determined that the corresponding operating condition has a promoting effect on the propagation of defects in the outer raceway, and the risk weight of the corresponding operating condition in the outer raceway fault map is increased.
[0038] It should be further explained that the coupling relationship between the defect propagation direction and the main load direction is used to characterize the influence of vehicle dynamic conditions on the external rolling track defect propagation behavior; when the continuous change of driving torque causes the main load direction to change, the abnormal impact angle migration direction changes synchronously, indicating that there is a correlation between vehicle operating conditions and external rolling track defect propagation behavior; by increasing the risk weight of the corresponding operating conditions in the external rolling track fault map, the key monitoring of the external rolling track defect propagation trend under high-risk operating conditions can be achieved. Example 2
[0039] In the above embodiments, since the drive motor of new energy vehicles operates under dynamic conditions such as regenerative braking, rapid acceleration, and complex road conditions for a long time, external random impacts, transient load changes, and dynamic shaft offsets can cause short-term deviations in the abnormal impact angle. If the abnormal impacts corresponding to these short-term deviations are retained in the outer rolling track fault map for a long time, it is easy to cause the risk area of the fault map to spread, historical anomalies to accumulate, and misjudgment of the direction of outer rolling track defect expansion, thereby reducing the accuracy of the prediction of the outer rolling track fault expansion trend. In order to solve this problem, in this embodiment, the establishment of the outer rolling track fault map and the prediction of the target angle region of the next abnormal impact include The system continuously analyzes the abnormal impact angle offsets in different time periods. When an abnormal impact only causes an angle offset during a short period of operating condition change, and the corresponding abnormal impact does not recur in subsequent time periods, the corresponding abnormal impact is determined to be a transient offset impact. The risk weight of the transient offset impact in the outer raceway fault map is reduced, and the risk coverage of the corresponding angle region is narrowed. The risk weight of the abnormal impact angle migration trajectory that recurs in multiple consecutive time periods is increased to construct a continuously updated dynamic fault map. Based on the updated dynamic fault map, the target angle region of the next abnormal impact and the expansion direction of the outer raceway defect are predicted.
[0040] It should be further explained that the transient bias impact is used to characterize non-persistent abnormal impacts caused by short-term external disturbances; in the persistence analysis, by comparing the recurrence of abnormal impacts in multiple consecutive time periods, it is determined whether the corresponding abnormal impact has long-term stable migration characteristics; when the abnormal impact only occurs under local short-term conditions and does not form a continuous migration trajectory, the risk weight of the corresponding abnormal impact in the outer raceway fault map is reduced to reduce the impact of short-term random impacts on the fault map update results; the risk coverage range is used to characterize the influence area of the abnormal impact in the angle domain. By reducing the risk coverage range of the angle region corresponding to the transient bias impact, the interference of historical random anomalies on the subsequent prediction results of the outer raceway defect expansion trend is reduced; by increasing the risk weight of the abnormal impact angle migration trajectory that recurs in multiple consecutive time periods, the dynamic fault map prioritizes the retention of long-term stable outer raceway defect expansion information, thereby improving the stability of the prediction results of the outer raceway fault expansion direction. Example 3
[0041] In the above embodiments, although reducing the risk weight of transient offset impacts in the outer rolling track fault map can reduce the interference of short-term abnormal impacts on the fault map, during the long-term variable operating conditions of new energy vehicles, the vehicle load direction, driving torque, and road excitation continuously change, and the abnormal impact angle migration direction in different time periods may still fluctuate frequently. If the angle migration direction in each time period is directly used for fault map updates, it is easy to cause frequent jumps in the risk area in the fault map, which in turn causes instability in the outer rolling track defect expansion path and distortion in the prediction of fault evolution trend, reducing the accuracy of identifying the long-term expansion behavior of outer rolling track defects. To solve this problem... Therefore, in this embodiment, the construction of a continuously updated dynamic fault map further includes: continuously statistically analyzing the migration directions of abnormal impact angles in different time periods, calculating the recurrence frequency and duration corresponding to each migration direction; determining the migration direction with a recurrence frequency consistently higher than a preset stable threshold as the main migration direction; suppressing transient angle jumps that deviate from the main migration direction, and reducing the influence weight of the corresponding abnormal impact on the update results of the outer raceway fault map; constructing a stable evolutionary main trajectory of the outer raceway defect based on the main migration direction, and predicting the subsequent expansion path and risk growth trend of the outer raceway defect based on the stable evolutionary main trajectory.
[0042] It should be further explained that the main migration direction is used to characterize the main expansion trend of the outer raceway defect during long-term operation; the recurrence frequency and duration are used to reflect the stability of the migration direction of different abnormal impact angles; by continuously statistically analyzing the migration direction of abnormal impact angles in different time periods, the long-term stable abnormal impact expansion trend is identified; when some abnormal impact angle migration directions only appear briefly and deviate from the main migration direction, the corresponding transient angle jumps are suppressed to reduce the fault map direction shift caused by short-term operating disturbances; the stable evolution main trajectory is used to characterize the long-term expansion path of the outer raceway defect in multiple time periods; by constructing a stable evolution main trajectory based on the main migration direction, the outer raceway fault map can continuously track the actual expansion behavior of the outer raceway defect, thereby improving the reliability and continuity of the prediction results of the subsequent expansion path and risk growth trend of the outer raceway defect.
[0043] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.
Claims
1. A method for detecting faults in the outer raceway of a rolling bearing in a three-phase asynchronous motor, characterized in that, Includes the following steps: S1. Collect the stator current signal during the operation of the three-phase asynchronous motor, and estimate the instantaneous speed of the rotor of the three-phase asynchronous motor based on the stator current signal; S2. Construct multiple rotational analysis segments based on preset reference angles. Each rotational analysis segment starts from the corresponding reference angle and ends after the three-phase asynchronous motor rotates a preset number of times. Combined with the instantaneous speed within the corresponding time period, perform local equal-angle resampling on the stator current signal in each rotational analysis segment to obtain the angle domain fault impact signal within the corresponding time period. S3. Extract abnormal impact features from the angle domain fault impact signals corresponding to each time period to obtain the angle distribution location corresponding to the abnormal impact. S4. Compare the consistency of abnormal impact angle distribution in different time periods. When abnormal impacts in multiple time periods continuously appear in the same angle region, it is determined that there is a fixed outer raceway defect in the corresponding angle region. When the location of abnormal impact angle distribution migrates or expands, it is determined that the outer raceway defect is in an expanding evolution state. S5. Construct the abnormal impact angle migration trajectory based on the abnormal impact angle distribution location in different time periods, and analyze the correlation between abnormal impact and vehicle operating conditions in combination with vehicle operating condition information, so as to identify the operating condition triggering factors that induce the evolution of outer raceway defects. S6. Establish an outer raceway fault map based on the abnormal impact angle migration trajectory. The outer raceway fault map is used to record the angle distribution area, migration direction and corresponding working condition information of abnormal impact in different time periods. Based on the outer raceway fault map, predict the target angle area of the next abnormal impact and the expansion trend of outer raceway defects. S7. Generate early warning results for outer raceway faults based on the predicted target angle region.
2. The method for detecting faults in the outer raceway of a rolling bearing in a three-phase asynchronous motor according to claim 1, characterized in that, The step S1, which estimates the instantaneous speed of the three-phase asynchronous motor rotor based on the stator current signal, includes the following specific details: S1.1 Perform high-frequency noise suppression processing on the acquired three-phase stator current signal to filter out high-frequency interference components corresponding to the inverter PWM switching frequency; S1.
2. Lock the fundamental frequency of the noise-suppressed three-phase stator current signal to obtain the motor synchronization frequency; S1.3 Calculate the instantaneous mechanical speed of the rotor by combining the real-time operating voltage and current amplitude of the motor and the motor slip rate, and generate the corresponding instantaneous speed change curve.
3. The method for detecting faults in the outer raceway of a rolling bearing in a three-phase asynchronous motor according to claim 1, characterized in that, In step S2, each rotation analysis segment starts at a preset reference angle and ends after the motor rotates a preset number of times. The rotation angle corresponding to each sampling moment is calculated based on the instantaneous speed change curve within the corresponding time period. The stator current sampling points in the time domain are remapped to the angle domain coordinates corresponding to the fixed angle interval to form a local equal-angle resampling sequence within the corresponding time period.
4. The method for detecting faults in the outer raceway of a rolling bearing in a three-phase asynchronous motor according to claim 1, characterized in that, Step S3, which involves extracting abnormal impact features from the angle-domain fault impact signal, includes the following specific steps: S3.1 Perform Hilbert transform on the angle domain fault impact signal to obtain the envelope signal; S3.2 Perform order spectrum analysis on the envelope signal to extract the spectral energy corresponding to the order of the outer raceway fault characteristics; S3.3 Determine the angular distribution location and impact intensity corresponding to the abnormal impact based on the changes in spectral line amplitude.
5. The method for detecting faults in the outer raceway of a rolling bearing in a three-phase asynchronous motor according to claim 1, characterized in that, The step S4, comparing the consistency of the abnormal impact angle distribution locations across different time periods, includes the following: S4.1 Calculate the angular offset of the abnormal impact center and the angular range of the abnormal impact coverage in adjacent time periods; S4.2 When the abnormal impact center angle offset is less than the preset offset threshold in multiple consecutive time periods, the corresponding abnormal impact is determined to be a fixed outer raceway defect. S4.3 When the abnormal impact center angle offset continues to increase and the coverage angle range expands synchronously, it is determined that the corresponding outer raceway defect is in an expansion evolution state.
6. The method for detecting faults in the outer raceway of a rolling bearing in a three-phase asynchronous motor according to claim 1, characterized in that, In step S5, when constructing the abnormal impact angle migration trajectory, the abnormal impact center angle, impact intensity and impact coverage of each time period are recorded in chronological order to form an abnormal impact angle time series. The abnormal impact angle migration speed is analyzed in conjunction with vehicle operating condition information to identify the corresponding relationship between the abnormal impact angle migration speed and the vehicle driving torque, regenerative braking state and vehicle driving section, so as to identify the operating condition triggering factors that induce the expansion of the outer rolling track defect. The step S6 of establishing the outer raceway fault map includes: constructing an angle heat matrix based on the distribution areas of abnormal impact angles in different time periods; The fault risk level of each angle region is generated based on the frequency and intensity of abnormal impacts in each angle region; the outer raceway defect propagation path map is generated based on the migration direction of the abnormal impact angle, and the target angle region of the next abnormal impact is predicted based on the outer raceway defect propagation path map.
7. The method for detecting faults in the outer raceway of a rolling bearing in a three-phase asynchronous motor according to claim 1, characterized in that, The outer raceway fault early warning result generated in S7 based on the predicted target angle region includes the following specific contents: S7.1 Improve the signal sampling frequency and abnormal impact detection sensitivity within the corresponding time period of the target angle area; S7.2 Calculate the abnormal impact growth rate in the target angle region; S7.3 When the abnormal impact growth rate continuously exceeds the preset growth threshold, generate the corresponding level of outer raceway fault warning information.
8. The method for detecting faults in the outer raceway of a rolling bearing in a three-phase asynchronous motor according to claim 1, characterized in that, The analysis of the correspondence between abnormal impact angle migration speed and vehicle operating conditions includes: obtaining the direction of change of driving torque, the magnitude of change of motor load, and the longitudinal acceleration of the vehicle under different operating conditions; determining the main action direction of the rolling bearing load based on the direction of change of driving torque, and calculating the coupling relationship between the defect propagation direction and the main action direction of the load in combination with the abnormal impact angle migration direction; when the abnormal impact angle migration direction and the main action direction of the load are continuously consistent, and the abnormal impact migration speed continuously increases with the increase of driving torque, it is determined that the corresponding operating condition has a promoting effect on the propagation of defects in the outer raceway, and the risk weight of the corresponding operating condition in the outer raceway fault map is increased.
9. A method for detecting faults in the outer raceway of a rolling bearing in a three-phase asynchronous motor according to claim 1, characterized in that, The process of establishing an outer raceway fault map and predicting the target angle region for the next abnormal impact includes: continuously analyzing the angle offset of abnormal impacts in different time periods; determining that the abnormal impact is a transient offset impact when the angle offset only occurs during short-term operating condition changes and the corresponding abnormal impact does not recur in subsequent time periods; reducing the risk weight of the transient offset impact in the outer raceway fault map and reducing the risk coverage of the corresponding angle region; increasing the risk weight of the abnormal impact angle migration trajectory that recurs in multiple consecutive time periods to construct a continuously updated dynamic fault map, and predicting the target angle region for the next abnormal impact and the direction of outer raceway defect expansion based on the updated dynamic fault map.
10. A method for detecting faults in the outer raceway of a rolling bearing in a three-phase asynchronous motor according to claim 9, characterized in that, The construction of a continuously updated dynamic fault map includes: continuously statistically analyzing the migration directions of abnormal impact angles in different time periods, calculating the recurrence frequency and duration of each migration direction; determining the migration direction with a recurrence frequency consistently higher than a preset stable threshold as the main migration direction; suppressing transient angle jumps that deviate from the main migration direction and reducing the influence weight of the corresponding abnormal impact on the update results of the outer raceway fault map; constructing a stable evolutionary main trajectory of the outer raceway defect based on the main migration direction, and predicting the subsequent expansion path and risk growth trend of the outer raceway defect based on the stable evolutionary main trajectory.