A motor health diagnosis system based on spectrum analysis

Abstract

The present application relates to the technical field of motor diagnosis, and particularly relates to a motor health diagnosis system based on spectrum analysis. The system comprises an information acquisition module, a signal transmission module, a database and a data processing module. The information acquisition module is used for monitoring the current information of the motor. The signal transmission module is electrically connected with the information acquisition module and transmits the information collected by the information acquisition module. The database is used for storing the original data of the monitored motor. The data processing module is electrically connected with the signal transmission module and the database, is used for receiving the amplified information of the signal transmission module, analyzing and processing the information, extracting the features that can be compared with the original data of the motor, and providing the monitoring result of the motor health according to the comparison result. The system can not only replace the manual real-time monitoring of the motor health, but also provide the motor fault type, so as to facilitate the timely maintenance of the operator and improve the motor fault elimination efficiency.

Description

Technical Field

[0001] This invention relates to the field of motor diagnostic technology, and in particular to a motor health diagnostic system based on spectrum analysis. Background Technology

[0002] With the widespread application of automated production, electric motors, as the power source for production, are widely used in manufacturing. Most motors used in production are three-phase asynchronous motors. The working principle of a three-phase asynchronous motor is as follows: When three-phase alternating current is applied to the stator windings, a rotating, changing magnetic field is established in the air gap of the windings. This magnetic field induces a current in the rotor. Because the rotor is in a changing magnetic field, it experiences Lorentz force, i.e., electromagnetic force, which drives the rotor to rotate.

[0003] The application of electric motors provides a stable power source for production to maintain continuous operation. Therefore, maintaining the stable operation of motors is crucial for production. Currently, motor health checks generally rely on manual inspections using testing equipment to periodically check motors and proactively eliminate faults. Common motor faults include insulation damage, insulation aging, inter-turn short circuits, phase-to-phase short circuits, or grounding faults. However, manual inspections are inefficient and struggle to detect internal motor faults in a timely manner. Therefore, a solution is urgently needed.

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

[0005] The technical problem to be solved by the present invention is to provide a motor health diagnosis system based on spectrum analysis. This system can not only replace manual monitoring of motor health in real time, but also provide motor fault types, which facilitates timely maintenance by operators and improves the efficiency of motor fault troubleshooting.

[0006] To achieve the aforementioned objective, the technical solution of the present invention is implemented as follows: a motor health diagnosis system based on spectrum analysis, comprising: an information acquisition module; the information acquisition module is used to monitor the current information of the motor; a signal transmission module; the signal transmission module is electrically connected to the information acquisition module and transmits the information acquired by the information acquisition module; a database; the database is used to store the raw data of the monitored motor; and a data processing module; the data processing module is electrically connected to both the signal transmission module and the database, and is used to receive the amplified information from the signal transmission module, analyze and process the information, extract features that can be compared with the raw motor data, and provide monitoring results of motor health based on the comparison results.

[0007] Preferably, the original data of the motor includes data on normal operation of the motor after it leaves the factory and operating data when several common faults occur during motor operation.

[0008] Preferably, the monitoring results of the motor health include determining whether the motor under monitoring is faulty, determining the current operating trend of the motor under monitoring, and predicting the impending fault of the motor under monitoring.

[0009] Preferably, the information acquisition module includes a Hall sensor; the Hall sensor is configured as an open-type Hall sensor and is installed on the cable connected to the motor to be monitored. The Hall sensor is used to acquire the current spectrum waveform of the current entering and exiting the motor to be monitored along the cable, and the sampling frequency of the Hall sensor is up to 10KHz, and the acquired current signal is transmitted to the signal transmission module.

[0010] Preferably, the signal transmission module includes an Ethernet switch.

[0011] Preferably, the data processing module includes a backend computer; the backend computer is electrically connected to an Ethernet switch, and the backend computer is equipped with online motor health monitoring software; the online motor health monitoring software is used to extract fault features from the current spectrum waveform collected by the Hall sensor, and the online motor health monitoring software establishes a mathematical mechanism model, which compares the fault features with the normal operation data of the motor under monitoring and the operation data when the motor malfunctions; the online motor health monitoring software displays the comparison results of the mathematical mechanism model on the computer screen in real time.

[0012] Preferably, the fault feature extraction process of the motor health online detection software for the current spectrum waveform includes sequential fundamental signal processing, Fourier transform, and spectrum correction; the fundamental signal processing uses an adaptive fundamental cancellation method to cancel the fundamental signal in the current spectrum waveform signal, highlighting the fault feature signal in the current spectrum waveform signal; the Fourier transform amplifies the fault feature signal in the current spectrum waveform signal through Fourier transform; the spectrum correction is used to refine the fault feature signal in the amplified current spectrum waveform signal at high frequencies, extracting high-precision fault feature signals.

[0013] Preferably, the online motor health detection software calculates the vector value of the fundamental Nth harmonic of the current spectrum waveform. This value is normalized to the vector value parameter of the standard 5th harmonic in the database. Under normal circumstances, it is a value no greater than 1, and X = actual value / reference value.

[0014] Preferably, the current spectrum waveform acquired by the Hall sensor is used to reflect the spectral envelope of 0-400Hz related to motor faults.

[0015] Preferably, the current spectrum waveform acquired by the Hall sensor is used to reflect the symmetry of the three phases A, B, and C, and its amplitude is expressed as: U = 2(5*Ie) / √2H, where Ie is a vector value, H is the transformation ratio of the Hall sensor, and the current / voltage value.

[0016] The beneficial effects of this invention are reflected in:

[0017] (1) This invention, through a motor online monitoring system based on spectrum analysis, effectively avoids various losses caused by motor "failure to be inspected," and transforms the periodic maintenance of equipment into condition-based maintenance, avoiding motor damage and equipment downtime caused by "over-inspection." Online monitoring of motors can reduce maintenance intensity by more than 50%, and the number of unplanned motor downtimes can be reduced to 40% of the original amount.

[0018] (2) The present invention can determine the fault of the motor under test through the motor diagnostic system, such as stator winding abnormality, rotor winding abnormality, iron core air gap abnormality, etc., so as to provide maintenance personnel with maintenance guidance, enabling maintenance personnel to carry out motor fault troubleshooting and maintenance work in a short time and improve the maintenance efficiency of motor. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the online motor monitoring of the present invention;

[0020] Figure 2 This is a schematic diagram of the motor monitoring system of the present invention;

[0021] Figure 3 This is a comparison diagram of the normal three-phase current spectrum and the three-phase current spectrum of the motor under inter-turn short circuit of the present invention.

[0022] Figure 4 This is a frequency domain waveform diagram of the motor under inter-turn short circuit conditions according to the present invention;

[0023] Figure 5 This is a waveform diagram showing the characteristic characteristics of the motor stator current spectrum analysis of the present invention. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Example 1

[0026] See Figure 1-5 As shown:

[0027] This invention provides a motor health diagnosis system based on spectrum analysis, comprising: an information acquisition module; the information acquisition module is used to monitor the current information of the motor.

[0028] The signal transmission module is electrically connected to the information acquisition module and transmits the information acquired by the information acquisition module. The signal transmission module includes an Ethernet switch.

[0029] The information acquisition module includes a Hall sensor; the Hall sensor is used to acquire the current spectrum waveform of the current entering and exiting the motor to be monitored along the cable, and the Hall sensor has a maximum sampling frequency of 100KHz, and transmits the acquired current signal to the signal transmission module.

[0030] In actual use, the Hall sensor used is an open-type Hall sensor, installed on the cable connected to the motor being monitored. Using an open-type Hall sensor eliminates the need to disassemble the cable during installation. During installation, ensure that the arrow on the Hall sensor points in the same direction as the current flow. To ensure sufficient insulation, the Hall sensor should be installed away from exposed live connectors; the gap between the Hall sensor and the cable should be filled with insulating rubber pads; connect the Hall terminals according to the wiring definition, and after wiring, wrap the terminals and cable with high-voltage insulating tape. To ensure insulation reliability, at least three insulation layers are required; the cable should be routed along the cabinet wall, ensuring safe, reliable, and aesthetically pleasing cabling.

[0031] By using Hall effect sensors in this way, sampling accuracy is improved. Furthermore, the collected information can be transmitted via Ethernet, enhancing the convenience and stability of information transmission.

[0032] Because of the high voltage resistance of the Hall sensor, it can work normally under the condition of 17.4kV / 15min with cable withstand voltage test, thus enabling stable acquisition of the current signal of the motor under test.

[0033] Meanwhile, the Hall sensor provides non-invasive monitoring, which not only does not affect the normal operation of the monitored motor, but is also safer to use and improves the security of information collection.

[0034] Database; The database is used to store the raw data of the monitored motor. The raw data of the motor is set as the normal operating data of the motor after it leaves the factory and the operating data when several common faults occur during motor operation.

[0035] The initial database is set up in this way because each motor is different (manufacturer, commissioning time, working environment, parameter differences, etc.), making it impossible to use a uniform standard to measure the health of a motor. Therefore, the database establishes its own archive for each motor. As the amount of data accumulates, the system has more and more data to refer to for judgment, thereby making the measurement accuracy of the entire system increasingly accurate.

[0036] Data processing module; The data processing module is electrically connected to the signal transmission module and the database. It is used to receive the information amplified by the signal transmission module, analyze and process the information, extract features that can be compared with the original motor data, and provide monitoring results of motor health based on the comparison results.

[0037] The data processing module includes a back-end computer; the back-end computer is electrically connected to an Ethernet switch, and the back-end computer is equipped with online motor health monitoring software.

[0038] The online motor health monitoring software is used to extract fault features from the current spectrum waveform collected by the Hall sensor. The software also includes a mathematical mechanism model that compares the fault features with the normal operating data of the motor under monitoring and the operating data when the motor malfunctions. The software displays the comparison results of the mathematical mechanism model on the computer screen in real time.

[0039] In practical applications, a series of mathematical mechanism models can be established for common motor faults encountered in daily use. Initial motor diagnosis mainly involves comparing monitoring data with model information to derive preliminary diagnostic suggestions for the motor.

[0040] The fault feature extraction process of the motor health online detection software for the current spectrum waveform includes fundamental signal processing, Fourier transform, and spectrum correction performed sequentially.

[0041] Fundamental signal processing uses an adaptive fundamental cancellation method to cancel the fundamental signal in the current spectrum waveform signal, thus highlighting the fault characteristic signal in the current spectrum waveform signal.

[0042] The Fourier transform amplifies the fault characteristic signals in the current spectrum waveform signal through the Fourier transform.

[0043] Spectrum correction is used to refine the fault feature signals in the amplified current spectrum waveform signal at high frequencies, and extract high-precision fault feature signals.

[0044] The online motor health monitoring software calculates the vector value of the Nth harmonic of the fundamental frequency of the current spectrum waveform. This value is normalized to the vector value parameter of the standard 5th harmonic in the database. Under normal circumstances, it is a value no greater than 1. The smaller the vector value, the better the motor health status, and X = actual value / reference value.

[0045] The current spectrum waveform collected by the Hall sensor is used to reflect the spectrum envelope related to motor faults in the range of 0-400Hz. The fewer the envelope curves or the smaller the amplitude, the higher the health level of the motor being monitored.

[0046] The current spectrum waveform acquired by the Hall sensor reflects the symmetry of the three phases A, B, and C. Its amplitude is expressed as: U = 2(5*Ie) / √2H, where Ie is the vector value, H is the turns ratio of the Hall sensor, and the current / voltage ratio is the value of the current. The more uniform the three-phase amplitudes, the better the symmetry and the healthier the motor windings.

[0047] The monitoring results of motor health include determining whether the motor under monitoring is faulty, judging the current operating status trend of the motor under monitoring, and predicting the impending fault of the motor under monitoring.

[0048] In addition, the online motor health monitoring software has the following ports for displaying the operating information of the motor to be monitored:

[0049] The device list port displays all monitored motors, including motor name, current health status and health score, device data update time, and number of monitoring days. When a motor malfunctions, the fault type is pushed to the user. Clicking the motor tag will directly take you to the motor monitoring interface. The device list is arranged in a logical order of fault-potential-health.

[0050] Alarm information list port; The alarm information list port is mainly used to display new motor faults in this list. The latest alarm information is displayed for the same motor, and the remaining alarms are arranged in chronological order.

[0051] Power Health Status Portal: The power health status port displays information in a coordinate system. The horizontal axis represents the number of motors, and the vertical axis represents the motor's health score. Each dot represents a motor. Moving the mouse over the corresponding dot displays information such as the motor's name, power, and health score. Larger dots indicate higher motor power. Orange dots indicate a potential safety hazard, while red dots indicate a malfunction. Clicking a dot quickly accesses the motor monitoring interface.

[0052] Alarm device statistics port; the alarm device statistics port also displays information in the form of a coordinate system, with the horizontal axis representing the date and the vertical axis representing the number of faulty motors. When a new faulty motor is added each day, it is added according to the health status of the device. Blue indicates alarms, and pink indicates faults. Clicking on any curve will hide or show that type of device.

[0053] Maintenance and troubleshooting port; The maintenance and troubleshooting port is mainly used to initiate troubleshooting when a motor fault is detected, or when other abnormalities are found during motor inspection that need to be handled, so as to facilitate the tracking of problem handling and realize closed-loop maintenance.

[0054] Maintenance Plan Portal: The maintenance plan port is used to manage common motor tasks such as "lubrication", "bearing replacement" and "experimentation". The system presets corresponding work cycles and will notify the user to perform the corresponding work when the preset time node is reached.

[0055] In actual use, operators can view the information of the motor to be monitored in a timely manner by clicking on various ports on the online motor health monitoring software, and handle faults promptly, which is convenient and efficient.

[0056] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A motor health diagnosis system based on spectrum analysis, characterized in that, include: Information collection module; The information acquisition module is used to monitor the current information of the motor; Signal transmission module; The signal transmission module is electrically connected to the information acquisition module and transmits the information acquired by the information acquisition module; the database is used to store the raw data of the monitored motor; the data processing module is electrically connected to both the signal transmission module and the database, and is used to receive the amplified information from the signal transmission module, analyze and process the information, extract features that can be compared with the raw data of the motor, and provide monitoring results of the motor health based on the comparison results. The original data of the motor includes the normal operating data of the motor after it leaves the factory and the operating data when the motor experiences several common faults during operation. The information acquisition module includes a Hall sensor; the Hall sensor is configured as an open-type Hall sensor and is installed on the cable connected to the motor to be monitored. The Hall sensor is used to acquire the current spectrum waveform of the current entering and exiting the motor to be monitored along the cable, and the highest sampling frequency of the Hall sensor is 10KHz, and the acquired current signal is transmitted to the signal transmission module. The data processing module includes a back-end computer; the back-end computer is equipped with online motor health monitoring software; the online motor health monitoring software establishes a mathematical mechanism model, which compares the fault characteristics with the normal operation data of the motor under monitoring and the operation data when the motor malfunctions; the online motor health monitoring software displays the comparison results of the mathematical mechanism model on the computer screen in real time. The online motor health monitoring software is used to extract fault features from the current spectrum waveforms collected by the Hall sensor. The fault feature extraction process of the motor health online detection software for the current spectrum waveform includes sequential fundamental signal processing, Fourier transform, and spectrum correction. The fundamental signal processing uses an adaptive fundamental cancellation method to cancel the fundamental signal in the current spectrum waveform signal, highlighting the fault feature signals in the current spectrum waveform signal. The Fourier transform amplifies the fault feature signals in the current spectrum waveform signal. The spectrum correction is used to refine the fault feature signals in the amplified current spectrum waveform signal at high frequencies, extracting high-precision fault feature signals. The online motor health monitoring software has the following ports for displaying the operating information of the motor to be monitored: Device list ports; This is used to display the name, current health status and health score of all monitored motors, equipment data update time and monitoring operation days. The equipment list is arranged in the logical order of fault-potential-health. Alarm information list port; used to display new motor faults in this list. The latest alarm information is displayed for the same motor, and the remaining alarms are arranged in chronological order. The power health status port displays information in the form of a coordinate system. The horizontal axis represents the number of motors and the vertical axis represents the motor health score. Each dot represents a motor. Moving the mouse to the corresponding dot will display the current motor name, power, and health score information. Clicking the dot will take you to the motor monitoring interface. Alarm device statistics port; information is displayed in the form of a coordinate system, with the horizontal axis representing the date and the vertical axis representing the number of faulty motors. Clicking on any curve can hide or show the corresponding faulty motor. Maintenance and troubleshooting of ports; It is used to initiate troubleshooting when a motor fault is detected, or when other abnormalities are found during motor inspection that require handling, and to track the handling of problems. The maintenance plan port is used to manage common motor maintenance tasks such as "lubrication", "bearing replacement" and "experimentation". The system presets corresponding work cycles and reminds users to perform motor maintenance according to the work cycle.

2. The motor health diagnosis system based on spectrum analysis according to claim 1, characterized in that, The monitoring results of the motor health include determining whether the motor under monitoring is faulty, determining the current operating trend of the motor under monitoring, and predicting the impending fault of the motor under monitoring.

3. The motor health diagnosis system based on spectrum analysis according to claim 2, characterized in that, The signal transmission module includes an Ethernet switch.

4. The motor health diagnosis system based on spectrum analysis according to claim 3, characterized in that, The back-end computer is electrically connected to the Ethernet switch.

5. The motor health diagnosis system based on spectrum analysis according to claim 4, characterized in that, The online motor health monitoring software calculates the vector value of the fundamental Nth harmonic of the current spectrum waveform. This value is normalized to the vector value parameter of the standard 5th harmonic in the database. Under normal circumstances, it is a value no greater than 1, and X = actual value / reference value.

6. The motor health diagnosis system based on spectrum analysis according to claim 5, characterized in that, The current spectrum waveform acquired by the Hall sensor is used to reflect the spectral envelope of 0-400Hz related to motor faults.

7. The motor health diagnosis system based on spectrum analysis according to claim 6, characterized in that, The current spectrum waveform acquired by the Hall sensor is used to reflect the symmetry of the three phases A, B, and C. Its amplitude is expressed as: U = 2(5*Ie) / H, where Ie is the vector value, H is the transformation ratio of the Hall sensor, and the current / voltage value.

Images