A motor fault detection method and system and a storage medium

Abstract

The application discloses a motor fault detection method and system and a storage medium in the field of motor detection, and comprises the following steps: collecting vibration acceleration of a detection motor, integrating the vibration acceleration, and obtaining primary motor speed information; after the primary motor speed information is subjected to detrending processing, a motor speed effective value is calculated and obtained; the motor state is judged according to the motor speed effective value, and a preset acceleration alarm range under each motor state is extracted; the vibration acceleration exceeding the acceleration alarm range is counted, and an alarm is given when the counting frequency in the detection period is greater than a corresponding set threshold value; the application reduces the influence of drift by simple detrending, finally obtains the effective value of the speed, reduces the influence of noise signals and vibration on detection, and improves the diagnosis precision of motor fault results.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of motor detection, and particularly relates to a motor fault detection method and system and a storage medium. BACKGROUND

[0002] Motors have been used more and more widely since the industrial revolution, and are commonly used in various scenes such as daily household applications, large-scale production and manufacturing equipment, and special applications such as coal mining, and the demand for monitoring of the motors is deepening.

[0003] In the prior art, a motor speed sensor is installed on an end cover of a motor to monitor the speed of the motor in real time and convert the speed signal into a speed electrical signal; a three-axis acceleration sensor is directly installed on a motor base to detect vibration acceleration of the motor in three directions of an axial direction X, a radial direction Y and a vertical direction Z in real time and convert the vibration acceleration signal into an acceleration electrical signal; a signal acquisition module is connected to the motor speed sensor and the three-axis acceleration sensor to acquire and transmit the speed electrical signal and the acceleration electrical signal; and an upper computer is installed with a database, receives the speed electrical signal and the acceleration electrical signal, and compares and analyzes the speed electrical signal and the acceleration electrical signal with information in the database to diagnose whether the motor is currently in a fault range. However, in the case of a change in the speed of the motor, the vibration data acquired by the detection method with a fixed sampling frequency is often not integral period data, which causes deviation of the calculation result, and the acquired speed electrical signal and acceleration electrical signal often contain noise signals, so the accuracy of the diagnosis result of the motor fault is low, and further improvement is needed. SUMMARY

[0004] The application aims to provide a motor fault detection method, system and storage medium, which obtains an acceleration signal by a three-axis acceleration sensor, performs integral algorithm on an acceleration waveform acquired by continuous sampling, reduces the influence of drift by a simple detrending item, and finally obtains an effective value of speed, reduces the influence of noise signals and vibration on detection, and improves the diagnosis accuracy of the motor fault result.

[0005] To achieve the above object, the technical scheme adopted by the application is as follows:

[0006] The application provides a motor fault detection method in a first aspect, which comprises the following steps.

[0007] The three-axis acceleration sensor is used to acquire vibration acceleration in three directions perpendicular to each other of the motor, and the vibration acceleration is integrated to obtain primary motor speed information.

[0008] After the detrending item processing of the primary motor speed information, the motor speed effective value is calculated and obtained.

[0009] The motor speed effective value is re-detected every interval detection period, the motor state is judged according to the motor speed effective value, and the preset acceleration alarm range under each motor state is extracted; the vibration acceleration exceeding the acceleration alarm range is counted, and when the number of counts in the detection period is greater than the corresponding set threshold, an alarm is given.

[0010] Preferably, the method for integrating the vibration acceleration is rectangular integration, trapezoidal integration, adaptive integration or Monte Carlo integration.

[0011] Preferably, the method for removing the trend item from the primary motor speed information comprises:

[0012] The average value of the primary motor speed corresponding to each time point is calculated, and each primary motor speed group is subtracted by the average value to obtain a motor speed approximate value array.

[0013] Preferably, the method for calculating the motor speed effective value comprises:

[0014] The root mean square of the motor speed approximate value array in the detection period is calculated as the motor speed effective value, and the expression formula is:

[0015]

[0016] In the formula, x represents the motor speed approximate value; and n represents the number of motor speed approximate values in the detection period.

[0017] Preferably, the range of the detection period is 2-4 seconds.

[0018] Preferably, the method for re-detecting the motor speed effective value every interval detection period and judging the motor state according to the motor speed effective value comprises:

[0019] The initial state of the motor is set as the start-up state, the motor state of the last detection period is obtained and whether it is the start-up state is judged;

[0020] If the motor speed effective value at the starting time point of the current detection period is greater than the motor speed effective value at the ending time point of the last detection period, the decrease starting point is cleared and the increase starting point is added, the time point of the motor speed effective value increase is counted, and when the count of the time point is greater than the time threshold, the motor state of the current detection period is judged as the start-up state;

[0021] If the motor speed effective value at the starting time point of the current detection period is less than the motor speed effective value at the ending time point of the last detection period, the increase starting point is cleared and the decrease starting point is added, the time point of the motor speed effective value decrease is counted, and when the count of the time point is greater than the time threshold, the motor state of the current detection period is judged as the shutdown state;

[0022] When the count of the time point is less than the time threshold, the motor state of the last detection cycle is maintained, and the next detection cycle is re-entered.

[0023] Preferably, the acceleration alarm range of the motor start state is [a1, a2], a1<0<a2; and the acceleration alarm range of the motor stop state is [a3, a4], a3<0<a4.

[0024] The second aspect of the present application provides a motor fault detection system, comprising:

[0025] The information acquisition module is used for acquiring vibration acceleration in three directions perpendicular to each other of the detection motor through the three-axis acceleration sensor, and obtaining primary motor speed information by integrating the vibration acceleration.

[0026] The analysis processing module is used for calculating the motor speed effective value after the primary motor speed information is processed by removing the trend term.

[0027] The state judgment module is used for re-detecting the motor speed effective value every interval detection cycle, judging the motor state according to the motor speed effective value,

[0028] The early warning module is used for extracting a preset acceleration alarm range under each motor state, counting the vibration acceleration exceeding the acceleration alarm range, and alarming when the count in the detection cycle is greater than the corresponding set threshold.

[0029] The third aspect of the present application provides a computer readable storage medium, characterized in that a computer program is stored thereon, and the program is executed by a processor to realize the steps of the detection method.

[0030] Compared with the prior art, the present application has the following beneficial effects:

[0031] The present application acquires vibration acceleration in three directions perpendicular to each other of the detection motor through the three-axis acceleration sensor, integrates the vibration acceleration to obtain primary motor speed information, removes the trend term after processing the primary motor speed information, calculates a relatively accurate motor speed effective value, reduces the influence of drift by simple trend removal, reduces the influence of noise signals and vibration on detection, and is beneficial to improve the diagnostic accuracy of motor fault results.

[0032] The present application re-detects the motor speed effective value every interval detection cycle, judges the motor state according to the motor speed effective value, extracts a preset acceleration alarm range under each motor state, counts the vibration acceleration exceeding the acceleration alarm range, and alarms when the count in the detection cycle is greater than the corresponding set threshold; different motor states have corresponding acceleration alarm ranges, and the speed and acceleration of the motor in different states are monitored at the same time, so that the diagnosis of motor fault results is more accurate. Attached Figure Description

[0033] Figure 1 This is a flowchart of the process for collecting the effective value of motor speed provided in an embodiment of the present invention;

[0034] Figure 2 This is an alarm flowchart of a motor fault detection method provided in an embodiment of the present invention;

[0035] Figure 3 This is a flowchart of motor status detection provided in an embodiment of the present invention. Detailed Implementation

[0036] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0037] Example 1

[0038] like Figures 1 to 3 As shown, a method for detecting motor faults includes: acquiring vibration accelerations of the motor in three mutually perpendicular directions using a triaxial accelerometer, integrating the vibration accelerations to obtain primary motor speed information; the method for integrating the vibration accelerations is rectangular integration, trapezoidal integration, adaptive integration, or Monte Carlo integration.

[0039] The primary motor speed information is detrended, including:

[0040] Calculate the average value of the primary motor speed at each time point, and subtract the average value from each primary motor speed group to obtain an array of approximate motor speed values; reduce the impact of drift by using a simple detrending term.

[0041] Calculate the root mean square of the array of approximate motor speed values ​​within the detection period as the effective value of the motor speed, thereby reducing the influence of noise signals and vibration on the detection. The formula is as follows:

[0042]

[0043] In the formula, x represents the approximate value of the motor speed; n represents the number of approximate values ​​of the motor speed within the detection cycle.

[0044] The effective value of the motor speed is re-detected at each interval. In this implementation, the detection interval is set to 3 seconds. The motor status is determined based on the effective value of the motor speed. The method includes:

[0045] Set the initial state of the motor to the powered-on state, obtain the motor state of the previous detection cycle, and determine whether it is powered-on.

[0046] If the motor speed effective value at the starting time point of the current detection period is greater than the motor speed effective value at the ending time point of the previous detection period, the starting point zero reset and the starting point addition increase will be reduced, the time point of the motor speed effective value increase is counted, and when the time point count is greater than the time threshold, the motor state of the current detection period is determined as the start state;

[0047] If the motor speed effective value at the starting time point of the current detection period is less than the motor speed effective value at the ending time point of the previous detection period, the starting point zero reset and the starting point addition decrease will be increased, the time point of the motor speed effective value decrease is counted, and when the time point count is greater than the time threshold, the motor state of the current detection period is determined as the stop state.

[0048] When the time point count is less than the time threshold, the motor state determined in the previous detection period is maintained, and the next detection period is re-entered.

[0049] The acceleration alarm range preset for each motor state is extracted, and the vibration acceleration exceeding the acceleration alarm range is counted. When the number of counts in the detection period is greater than the corresponding set threshold, an alarm is given. The acceleration alarm range of the motor start state is [a1, a2], a1<0<a2; the acceleration alarm range of the motor stop state is [a3, a4], a3<0<a4. Different motor states have corresponding acceleration alarm ranges, and the acceleration of the motor in different states is monitored at the same time, so that the diagnosis of motor fault results is more accurate.

[0050] Embodiment Two

[0051] The embodiment provides a motor fault detection system, and the detection system provided by the embodiment can be applied to the detection method in Embodiment One. The detection system comprises:

[0052] An information acquisition module is configured to acquire vibration accelerations in three directions perpendicular to each other of a detection motor by a three-axis acceleration sensor, and to obtain primary motor speed information by integrating the vibration accelerations.

[0053] An analysis processing module is configured to calculate a motor speed effective value after performing a detrending item processing on the primary motor speed information.

[0054] A state judgment module is configured to re-detect the motor speed effective value every detection period, and to determine a motor state according to the motor speed effective value.

[0055] A warning module is configured to extract an acceleration alarm range preset for each motor state, and to count the vibration accelerations exceeding the acceleration alarm range respectively. When the number of counts in the detection period is greater than a corresponding set threshold, an alarm is given.

[0056] Embodiment Three

[0057] The embodiment provides a computer readable storage medium, characterized in that a computer program is stored on the computer readable storage medium, and the computer program is executed by a processor to implement the steps of the motor fault detection method in the embodiment one.

[0058] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. In addition, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage media, etc.) containing computer-usable program code.

[0059] The present application is described with reference to flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of flows and / or blocks in the flowcharts and / or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing apparatus to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing apparatus generate a means for implementing the functions specified in the flowcharts and / or block diagrams. Figure 1 The functions specified in a flow or multiple flows and / or blocks Figure 1 The means for implementing the functions specified in a flow or multiple flows and / or blocks.

[0060] These computer program instructions can also be stored in a computer readable memory capable of directing the computer or other programmable data processing apparatus to work in a specific manner, so that the instructions stored in the computer readable memory produce a product including instruction means, which implements the functions specified in the flowcharts and / or block diagrams. Figure 1 The functions specified in a flow or multiple flows and / or blocks Figure 1 The means for implementing the functions specified in a flow or multiple flows and / or blocks.

[0061] These computer program instructions can also be loaded into a computer or other programmable data processing apparatus, so that a series of operation steps are performed on the computer or other programmable data processing apparatus to produce a computer-implemented process, so that the instructions executed on the computer or other programmable data processing apparatus provide a means for implementing the functions specified in the flowcharts and / or block diagrams. Figure 1 The functions specified in a flow or multiple flows and / or blocks Figure 1 The means for implementing the functions specified in a flow or multiple flows and / or blocks.

[0062] The above merely describes the preferred embodiments of the present application, and it should be pointed out that, for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present application, and these improvements and modifications should also be considered as the protection scope of the present application.

Claims

1. A method of detecting a fault in an electric machine, characterized in that, The method comprises the following steps: Collecting vibration acceleration in three directions perpendicular to each other of the motor, and integrating the vibration acceleration to obtain primary motor speed information; After removing the trend item from the primary motor speed information, the motor speed effective value is calculated; The motor speed effective value is detected again every detection period, and the motor state is determined according to the motor speed effective value, and the specific method comprises: The initial state of the motor is set as the start-up state, the motor state of the previous detection period is obtained, and it is determined whether it is the start-up state; If the motor speed effective value at the starting time point of the current detection period is greater than the motor speed effective value at the ending time point of the previous detection period, the starting point is cleared and added, the time point at which the motor speed effective value is increased is counted, and when the count of the time point is greater than a time threshold, it is determined that the motor state of the current detection period is the start-up state; If the motor speed effective value at the starting time point of the current detection period is less than the motor speed effective value at the ending time point of the previous detection period, the starting point is cleared and added, the time point at which the motor speed effective value is reduced is counted, and when the count of the time point is greater than a time threshold, it is determined that the motor state of the current detection period is the shutdown state; When the count of the time point is less than the time threshold, the motor state determined in the previous detection period is maintained, and the next detection period is entered again; The acceleration alarm range in each motor state is extracted, and the vibration acceleration exceeding the acceleration alarm range is counted, and when the count in the detection period is greater than a corresponding set threshold, an alarm is given.

2. A method of detecting a fault in an electric machine according to claim 1, characterized in that, The method for integrating the vibration acceleration is rectangular integration, trapezoidal integration, adaptive integration or Monte Carlo integration.

3. The method of claim 1, wherein, The method for removing the trend item from the primary motor speed information comprises: The average value of the primary motor speed at each time point is calculated, and the motor speed approximate value array is obtained by subtracting the average value from each primary motor speed group.

4. A method of detecting a fault in an electric machine according to claim 3, characterized in that, The method for calculating the motor speed effective value comprises: The root mean square of the motor speed approximate value array in the detection period is calculated as the motor speed effective value, and the expression formula is: ； In the formula, x represents the motor speed approximate value, n represents the number of motor speed approximate values in the detection period, and M represents the motor speed effective value.

5. The method of claim 1, wherein, The range of the detection period is 2-4 seconds.

6. The method of claim 1, wherein, The acceleration alarm range of the motor starting state is , ; the acceleration alarm range of the motor stopping state is .

7. A system for detecting a fault in an electric machine, characterized in that The method comprises the following steps: An information acquisition module is configured to collect vibration acceleration in three directions perpendicular to each other of the motor by a three-axis acceleration sensor, and integrate the vibration acceleration to obtain primary motor speed information; An analysis processing module is configured to remove the trend item from the primary motor speed information, and calculate the motor speed effective value; A state judgment module is configured to detect the motor speed effective value again every detection period, and determine the motor state according to the motor speed effective value, A warning module is configured to extract the acceleration alarm range in each motor state, count the vibration acceleration exceeding the acceleration alarm range, and give an alarm when the count in the detection period is greater than a corresponding set threshold; The state judgment module detects the motor speed effective value again every detection period, and determines the motor state according to the motor speed effective value, and the specific method comprises: The initial state of the motor is set as a start-up state, and the motor state of the last detection period is obtained and determined whether it is a start-up state; If the motor speed effective value at the starting time point of the current detection period is greater than the motor speed effective value at the ending time point of the last detection period, the starting point zero reset is reduced and the starting point increase is added, the time point of the motor speed effective value increase is counted, and when the time point count is greater than the time threshold, the motor state of the current detection period is determined as a start-up state; If the motor speed effective value at the starting time point of the current detection period is less than the motor speed effective value at the ending time point of the last detection period, the starting point zero reset is increased and the starting point decrease is added, the time point of the motor speed effective value decrease is counted, and when the time point count is greater than the time threshold, the motor state of the current detection period is determined as a shutdown state; When the time point count is less than the time threshold, the motor state determined in the last detection period is maintained, and the next detection period is re-entered.

8. A computer readable storage medium, characterized in that, The computer program is stored thereon, and the program is executed by the processor to realize the motor fault detection method steps in any one of claims 1 to 6.

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