Rotor broken bar fault diagnosis method, device and equipment of cage asynchronous motor

Abstract

The application discloses a rotor broken bar fault diagnosis method, device, equipment and medium of a cage asynchronous motor, the method comprises the following steps: in the process of injecting a voltage of a target frequency into a phase winding of the cage asynchronous motor, the response current of the winding and the corresponding mechanical position angle are acquired; wherein, before the voltage is injected, the cage asynchronous motor is in an unloaded state, and the rotor of the cage asynchronous motor rotates at a set speed; the peak-to-peak value of the current is determined according to the response current, and the correlation between the peak-to-peak value of the current and the mechanical position angle is determined; the response current is subjected to interpolation processing according to the correlation, and the reconstructed current is obtained; the fault feature is extracted from the reconstructed current, and the rotor broken bar fault diagnosis is carried out according to the fault feature. The application avoids the interference of the fundamental frequency component, and can effectively diagnose the rotor broken bar fault; only one-phase stator current and the mechanical position angle need to be collected, so that the non-invasive diagnosis is realized.

Description

Technical Field

[0001] This invention relates to the field of fault diagnosis technology, and in particular to a method, apparatus, equipment, and medium for diagnosing rotor bar breakage faults in a squirrel-cage induction motor. Background Technology

[0002] Squirrel-cage induction motors are widely used in industry, transportation, and national defense due to their simple structure and low cost. Under normal circumstances, squirrel-cage induction motors have high operational reliability. However, when operating under harsh conditions such as extreme temperatures, high humidity, heavy loads, and repeated starts and stops, they are prone to various serious failures. A typical failure of squirrel-cage induction motors is rotor bar breakage, caused by the fracture of the motor's conductor bars. If rotor bar breakage is not diagnosed promptly, the stress between the conductor bars will increase, potentially leading to further bar breakage and exacerbating the motor's malfunction.

[0003] For rotor bar breakage faults in squirrel-cage induction motors, existing research both domestically and internationally has proposed several diagnostic methods, primarily involving time-domain and frequency-domain analysis of various motor characteristics. These methods include phase current analysis, Park vector method, and zero-sequence current component analysis for current; phase voltage analysis and zero-sequence voltage analysis for voltage; instantaneous active and reactive power analysis for power; and air gap magnetic flux density distortion detection and injection methods for magnetic fields. However, these methods suffer from drawbacks such as the fault characteristic components being susceptible to interference from the fundamental frequency component, and the diagnostic methods being invasive. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the above-mentioned defects in the prior art and provide a method, device, equipment and medium for diagnosing rotor bar breakage faults in a double-cage asynchronous motor.

[0005] The present invention solves the above-mentioned technical problems through the following technical solution:

[0006] Firstly, a method for diagnosing rotor bar breakage faults in a squirrel-cage induction motor is provided, the method comprising:

[0007] During the process of injecting a voltage of the target frequency into one phase winding of the squirrel-cage induction motor, the response current of the winding and the corresponding mechanical position angle are obtained; wherein, before the voltage is injected, the squirrel-cage induction motor is in an unloaded state, and the rotor of the squirrel-cage induction motor rotates at a set speed;

[0008] The peak-to-peak value of the current is determined based on the response current, and the correlation between the peak-to-peak value of the current and the mechanical position angle is determined.

[0009] The response current is interpolated based on the correlation to obtain the reconstructed current;

[0010] Fault features are extracted from the reconstructed current, and rotor bar breakage fault diagnosis is performed based on the fault features.

[0011] Optionally, determining the peak-to-peak value of the current based on the response current includes:

[0012] Take the response current collected during the last mechanical cycle of the shutdown process from the response current;

[0013] The difference between the upper and lower envelope signals of the response current is determined as the peak-to-peak value of the current.

[0014] Optionally, extracting fault features from the reconstructed current includes:

[0015] Extract the DC component and the harmonic amplitude of the nth harmonic from the reconstructed current;

[0016] The fault characteristics are determined based on the harmonic amplitude and the DC component.

[0017] Optionally, determining fault characteristics based on the harmonic amplitude and the DC component includes:

[0018] The harmonic amplitude and the DC component are normalized.

[0019] The fault characteristics are determined based on the normalized harmonic amplitude and DC component.

[0020] Secondly, a rotor bar breakage fault diagnosis device for a squirrel-cage induction motor is provided, the rotor bar breakage fault diagnosis device comprising:

[0021] The acquisition module is used to acquire the response current and corresponding mechanical position angle of the winding during the process of injecting a voltage of the target frequency into one phase winding of the squirrel-cage asynchronous motor; wherein, before the voltage is injected, the squirrel-cage asynchronous motor is in an unloaded state and the rotor of the squirrel-cage asynchronous motor rotates at a set speed;

[0022] The determination module is used to determine the peak-to-peak value of the current based on the response current, and to determine the correlation between the peak-to-peak value of the current and the mechanical position angle;

[0023] The reconstruction module is used to interpolate the response current according to the correlation to obtain the reconstructed current;

[0024] The fault diagnosis module is used to extract fault features from the reconstructed current and perform rotor bar breakage fault diagnosis based on the fault features.

[0025] Optionally, the determining module includes:

[0026] An extraction unit is used to extract the response current collected during the last mechanical cycle of the shutdown process from the response current;

[0027] The determining unit determines the difference between the upper envelope signal and the lower envelope signal of the response current as the peak-to-peak value of the current.

[0028] Optionally, the fault diagnosis module includes:

[0029] An extraction unit is used to extract the DC component and the harmonic amplitude of the nth harmonic from the reconstructed current.

[0030] The determination unit determines the fault characteristics based on the harmonic amplitude and the DC component.

[0031] Optionally, the fault diagnosis module further includes:

[0032] The processing unit is used to normalize the harmonic amplitude and the DC component.

[0033] The diagnostic unit is used to determine the fault characteristics based on the normalized harmonic amplitude and the DC component.

[0034] Thirdly, an electronic device is provided, including a memory, a processor, and a computer program stored in the memory and used to run on the processor, wherein the processor executes the computer program to implement the rotor bar breakage fault diagnosis method of any of the above claims.

[0035] Fourthly, a computer-readable storage medium is provided, on which a computer program is stored, wherein when the computer program is executed by a processor, it implements the rotor bar breakage fault diagnosis method for any of the above-described double-cage asynchronous motors.

[0036] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention.

[0037] The positive and progressive effects of this invention are as follows: Based on the peak-to-peak current and mechanical position angle of the squirrel-cage asynchronous motor under set speed and no-load conditions, this invention analyzes the rotor bar breakage fault characteristics of the squirrel-cage asynchronous motor, which has the advantages of convenient implementation, fault characteristic components are not affected by fundamental frequency components, and non-invasive diagnosis can be achieved. Attached Figure Description

[0038] Figure 1 A flowchart illustrating a rotor bar breakage fault diagnosis method for a squirrel-cage induction motor, provided as an exemplary embodiment of the present invention;

[0039] Figure 2A schematic diagram of the curves of the acquired response current and mechanical position angle provided for an exemplary embodiment of the present invention;

[0040] Figure 3 A schematic diagram of the peak-to-peak value of current provided for an exemplary embodiment of the present invention;

[0041] Figure 4 A schematic diagram illustrating the correlation between dual mechanical position angles and the corresponding peak-to-peak value of the reconstructed current, provided as an exemplary embodiment of the present invention;

[0042] Figure 5 A schematic diagram of another collected response current and mechanical position angle provided for an exemplary embodiment of the present invention;

[0043] Figure 6 A schematic diagram of another current peak-to-peak value curve provided for an exemplary embodiment of the present invention;

[0044] Figure 7 A schematic diagram of the correlation between another dual mechanical position angle and the corresponding peak-to-peak value of the reconstructed current, provided as an exemplary embodiment of the present invention;

[0045] Figure 8 A schematic diagram of a rotor bar breakage fault diagnosis device for a squirrel-cage induction motor provided as an exemplary embodiment of the present invention;

[0046] Figure 9 This is a schematic diagram of the structure of an electronic device provided for an exemplary embodiment of the present invention. Detailed Implementation

[0047] The present invention will be further illustrated by way of embodiments below, but the present invention is not limited to the scope of the embodiments described herein.

[0048] This invention provides a method for diagnosing rotor bar breakage faults in a squirrel-cage induction motor. The number of phases and pole pairs of the squirrel-cage induction motor can be set according to actual conditions, and this invention does not impose any special limitations on this.

[0049] Figure 1 A flowchart of a rotor bar breakage fault diagnosis method for a squirrel-cage induction motor is provided as an exemplary embodiment of the present invention. The rotor bar breakage fault diagnosis method includes the following steps:

[0050] Step 101: During the process of injecting a voltage of the target frequency into one phase winding of the squirrel-cage induction motor, obtain the response current of the winding and the corresponding mechanical position angle.

[0051] Before the voltage is injected, the squirrel-cage induction motor is in an unloaded state, and the rotor of the squirrel-cage induction motor rotates at a set speed.

[0052] The so-called no-load state means that the squirrel-cage induction motor is not connected to a load. The set speed can be set according to the actual situation.

[0053] When a squirrel-cage induction motor is in an unloaded state, the motor shutdown time is relatively long, which facilitates rotor bar breakage diagnosis. However, under load, the motor shutdown time may be very short, which is not conducive to rotor bar breakage diagnosis. Setting a speed is to give the squirrel-cage induction motor an initial speed before shutdown. Preferably, the initial speed is greater than a speed threshold, i.e., a relatively high initial speed, to ensure that the motor shutdown time is long enough and to avoid a shutdown time that is too short due to a low initial speed, which is not conducive to rotor bar breakage diagnosis. Before injecting voltage, except for the winding of the phase with the target frequency, other phases can be short-circuited or open-circuited; this embodiment of the invention does not impose any particular limitation.

[0054] In one embodiment, the squirrel-cage induction motor has n pole pairs. Powered by an inverter, the motor's speed is pre-stabilized at a set speed. Under no-load conditions, all bridge arm pulse signals of the squirrel-cage induction motor are switched off to stop it. After a set time, a voltage of the target frequency is injected back into one phase winding. Simultaneously, the response current signal and mechanical position angle signal of the injected phase winding are acquired. The rotor rotates when the high-frequency voltage is injected. Here, the high-frequency voltage refers to a voltage signal with a frequency higher than the motor's base frequency before shutdown.

[0055] The target frequency voltage, also known as the high-frequency voltage, has a frequency greater than the base frequency voltage of the squirrel-cage induction motor before shutdown.

[0056] The injection node for the voltage at the target frequency can be, but is not limited to, the input terminal of the inverter or a single phase of the stator. The acquisition node for the response current signal can be the same as the injection node for the voltage at the target frequency, enabling non-invasive diagnostics.

[0057] It should be noted that during the injection of voltage at the target frequency, the response current signal and mechanical position angle signal are acquired multiple times. The acquisition period can be set according to actual needs to obtain the response current signal sequence and the mechanical position angle signal sequence. For the acquisition methods of the response current signal and mechanical position angle signal, please refer to the relevant technical descriptions; this embodiment of the invention does not impose any particular limitations on them.

[0058] Step 102: Determine the peak-to-peak current signal based on the response current signal, and determine the correlation between the peak-to-peak current signal and the mechanical position angle signal.

[0059] Since the peak-to-peak current signal and the mechanical position angle signal are acquired synchronously, a correlation between the two can be established.

[0060] It should be noted that synchronous acquisition does not mean that the acquisition time of the current peak-to-peak signal and the mechanical position angle signal must be exactly the same. When the difference between the acquisition time t1 of the current peak-to-peak signal a and the acquisition time t1' of the mechanical position angle signal b is less than the difference threshold, a correlation is established between the two, and the mechanical position angle signal b is the mechanical position angle signal corresponding to the current peak-to-peak signal a. The difference threshold can be determined according to the actual situation.

[0061] In one embodiment, the response current signal acquired during the last mechanical cycle of the shutdown process is extracted from the response current signal. The difference between the upper and lower envelope signals of the response current signal is determined as the peak-to-peak current signal, and the correlation between this peak-to-peak current signal and the corresponding mechanical position angle signal is determined. This peak-to-peak current signal can well characterize the fault features of rotor bar breakage, and the accuracy of rotor bar breakage diagnosis based on this signal is high.

[0062] One mechanical cycle of a squirrel-cage induction motor is one revolution of the rotor. Considering that eddy currents may still exist in the rotor during the first few mechanical cycles of the shutdown process, which may affect the accuracy of diagnosis, the response current signal collected in the last mechanical cycle is used for rotor bar breakage diagnosis to minimize the interference of eddy currents on rotor bar breakage diagnosis.

[0063] This relationship can be represented, but is not limited to, through graphs, functions, etc. For example, a one-dimensional lookup table can be established between the peak-to-peak current signal and the mechanical position angle signal, and interpolation processing can be performed based on this lookup table in step 103.

[0064] Step 103: Interpolate the response current signal according to the correlation to obtain the reconstructed current signal.

[0065] Because the rotor speed is uneven and gradually decreases when the machine is stopped, the step size between each mechanical position angle signal collected is not fixed. Through interpolation, a uniformly spaced response current signal, i.e. a reconstructed current signal, can be obtained, which is beneficial for fault feature extraction.

[0066] Step 104: Extract fault features from the reconstructed current signal and perform rotor bar breakage fault diagnosis based on the fault features.

[0067] In this embodiment of the invention, interference from the fundamental frequency component is avoided, which can effectively diagnose rotor bar breakage faults; only one phase stator current signal and mechanical position angle signal need to be collected, which is a non-invasive diagnosis.

[0068] In one embodiment, step 104 specifically includes: extracting the harmonic amplitude and DC component of the nth harmonic from the reconstructed current signal, and determining the fault characteristics based on the harmonic amplitude and DC component. n is a positive integer; for example, performing a Fast Fourier Transform on the reconstructed mechanical angle signal using the reconstructed peak-to-peak current signal, and extracting the 2p, 4p, 6p, and 8p harmonic amplitudes and DC components based on the characteristics of the rotor bar breakage fault.

[0069] Understandably, before extracting the harmonic amplitude and DC component of the nth harmonic from the reconstructed current signal, the peak-to-peak value of the reconstructed current signal is subjected to a Fast Fourier Transform (FFT) on the reconstructed mechanical angle signal, and then the harmonic amplitude and DC component of the nth harmonic are extracted.

[0070] In one embodiment, fault characteristics are determined by normalizing the harmonic amplitude and DC component, and then determining the fault characteristics based on the normalized harmonic amplitude and DC component.

[0071] In one embodiment, the extracted harmonic amplitudes are normalized to the DC component, the sum of squares is calculated and the square root is taken. This value is used as a fault characteristic quantity and compared with a set threshold to determine whether the motor has a rotor bar breakage fault.

[0072] In one embodiment, the formula for calculating the fault characteristic index is as follows:

[0073]

[0074] Among them, the reconstructed peak-to-peak current signals of the 2p, 4p, 6p, and 8p harmonic amplitudes and the DC component are respectively i _2p i _4p i _6p i _8p i _DC .

[0075] The fault characteristic quantity index is compared with the set threshold. If the index is greater than the set threshold, it is determined that a rotor bar breakage fault has occurred. If the index is less than the set threshold, it is determined that no rotor bar breakage fault has occurred.

[0076] The set threshold is calculated based on the response current signal and corresponding mechanical position angle signal of the squirrel-cage induction motor under normal conditions. The calculation process is similar to that of the fault characteristic quantity index, and will not be repeated here. Different models of squirrel-cage induction motors have different set thresholds.

[0077] In this embodiment of the invention, the fault feature quantity index can clearly characterize the fault characteristics of rotor bar breakage, thereby improving the accuracy of rotor bar breakage fault diagnosis.

[0078] The following describes the fault diagnosis process for a five-phase squirrel-cage asynchronous motor with a broken rotor bar, using a single rotor bar as an example. This five-phase squirrel-cage asynchronous motor has 2 pole pairs and is powered by an inverter. The fault diagnosis method of this invention specifically includes the following steps:

[0079] S11, the motor is pre-stabilized at the set speed of 500 rpm;

[0080] S12, under no-load conditions, shut down all bridge arm pulse signals to stop the machine;

[0081] S13, after a set time of 1 second, injects a sinusoidal voltage of 150Hz and 90V into phase A again, and at the same time collects the response current signal and mechanical position angle signal of the injected phase winding.

[0082] Figure 2 A schematic diagram of the acquired response current and mechanical position angle provided for an exemplary embodiment of the present invention;

[0083] S14, take the response current signal and mechanical position angle signal of the last mechanical cycle, and subtract the lower envelope from the upper envelope of the response current signal to obtain the peak-to-peak current signal.

[0084] Figure 3 A schematic diagram of a current peak-to-peak signal provided for an exemplary embodiment of the present invention;

[0085] S15, a one-dimensional lookup table is established using the obtained peak-to-peak current signal and mechanical position angle signal;

[0086] S16 reconstructs the mechanical position angle signal in the last mechanical cycle into a uniformly spaced signal, and uses the one-dimensional lookup table established in S15 to index the corresponding reconstructed current peak-to-peak signal through linear interpolation.

[0087] The reconstructed mechanical position angle signal and the corresponding reconstructed current peak-to-peak signal are as follows: Figure 4 As shown;

[0088] S17, perform FFT on the reconstructed current peak-to-peak signal and the reconstructed mechanical angle signal to extract the 2p, 4p, 6p and 8p harmonic amplitudes and DC components, which are 0.196460A, 0.197186A, 0.141536A, 0.142391A and 21.427007A, respectively;

[0089] S18, the calculated fault characteristic quantity index = 0.016017 is compared with the set threshold of 0.007. Since index is greater than the set threshold, it is determined that the motor has a rotor bar breakage fault.

[0090] The following describes the fault diagnosis process for a five-phase squirrel-cage asynchronous motor with a broken rotor bar, using a case of rotor bar breakage as an example. This five-phase squirrel-cage asynchronous motor has 2 pole pairs (p=2) and is powered by an inverter. The fault diagnosis method of this invention specifically includes the following steps:

[0091] S21, the motor is pre-stabilized at the set speed of 500 rpm;

[0092] S22, under no-load conditions, shut down all bridge arm pulse signals to stop the machine;

[0093] S23, after a set time of 1 second, injects a sinusoidal voltage of 150Hz and 90V into phase A again, and at the same time collects the response current signal and mechanical position angle signal of the injected phase winding.

[0094] Figure 5 A schematic diagram of another collected response current and mechanical position angle provided for an exemplary embodiment of the present invention;

[0095] S24, take the response current signal and mechanical position angle signal of the last mechanical cycle, and subtract the lower envelope from the upper envelope of the response current signal to obtain the peak-to-peak current signal.

[0096] Figure 6 A schematic diagram of another peak-to-peak current signal provided for an exemplary embodiment of the present invention;

[0097] S25, a one-dimensional lookup table is established using the obtained peak-to-peak current signal and the mechanical position angle signal in the last mechanical cycle;

[0098] S26, reconstruct the mechanical position angle signal in the last mechanical cycle into a uniformly spaced signal, and use the one-dimensional lookup table established in step 5 to index the corresponding reconstructed current peak-to-peak signal through linear interpolation.

[0099] The reconstructed mechanical position angle signal and the corresponding reconstructed current peak-to-peak signal are as follows: Figure 7 As shown;

[0100] S27, perform FFT on the reconstructed current peak-to-peak signal and the reconstructed mechanical angle signal to extract the 2p, 4p, 6p and 8p harmonic amplitudes and DC components, which are 0.084113A, 0.045342A, 0.020368A, 0.016362A and 30.561747A, respectively;

[0101] S28, the calculated fault characteristic quantity index = 0.003241 is compared with the set threshold of 0.007. Since index is less than the set threshold, it is determined that the motor has not experienced a rotor bar breakage fault.

[0102] Corresponding to the aforementioned embodiment of the rotor bar breakage fault diagnosis method for a double-cage asynchronous motor, the present invention also provides an embodiment of a rotor bar breakage fault diagnosis device for a double-cage asynchronous motor.

[0103] Figure 8 A rotor bar breakage fault diagnosis device for an asynchronous motor is provided as an exemplary embodiment of the present invention. The rotor bar breakage fault diagnosis device includes:

[0104] The acquisition module 81 is used to acquire the response current signal and the corresponding mechanical position angle signal of the winding during the process of injecting a voltage of the target frequency into one phase winding of the squirrel-cage asynchronous motor; wherein, before the voltage is injected, the squirrel-cage asynchronous motor is in an unloaded state and the rotor of the squirrel-cage asynchronous motor rotates at a set speed.

[0105] The determining module 82 is used to determine the peak-to-peak value of the current signal based on the response current signal, and to determine the correlation between the peak-to-peak value of the current signal and the mechanical position angle signal;

[0106] The reconstruction module 83 is used to interpolate the response current signal according to the correlation relationship to obtain the reconstructed current signal;

[0107] The fault diagnosis module 84 is used to extract fault features from the reconstructed current signal and perform rotor bar breakage fault diagnosis based on the fault features.

[0108] Optionally, the determining module includes:

[0109] An extraction unit is used to extract the response current signal collected during the last mechanical cycle of the shutdown process from the response current signal;

[0110] The determining unit determines the difference between the upper envelope signal and the lower envelope signal of the response current signal as the peak-to-peak value signal of the current.

[0111] Optionally, the fault diagnosis module includes:

[0112] An extraction unit is used to extract the DC component and the harmonic amplitude of the nth harmonic from the reconstructed current signal.

[0113] The determination unit determines the fault characteristics based on the harmonic amplitude and the DC component.

[0114] Optionally, the fault diagnosis module further includes:

[0115] The processing unit is used to normalize the harmonic amplitude and the DC component.

[0116] The diagnostic unit is used to determine the fault characteristics based on the normalized harmonic amplitude and the DC component.

[0117] For the device embodiments, since they basically correspond to the method embodiments, the relevant parts can be referred to in the description of the method embodiments. The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of the present invention according to actual needs.

[0118] Figure 9 This is a schematic diagram of the structure of an electronic device according to an example embodiment of the present invention, showing a block diagram of an exemplary electronic device 90 suitable for implementing embodiments of the present invention. Figure 9 The electronic device 90 shown is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments of the present invention.

[0119] like Figure 9 As shown, the electronic device 90 can be manifested as a general-purpose computing device, such as a server device. The components of the electronic device 90 may include, but are not limited to: at least one processor 91, at least one memory 92, and a bus 93 connecting different system components (including memory 92 and processor 91).

[0120] Bus 93 includes a data bus, an address bus, and a control bus.

[0121] The memory 92 may include volatile memory, such as random access memory (RAM) 921 and / or cache memory 922, and may further include read-only memory (ROM) 923.

[0122] The memory 92 may also include a program tool 925 (or utility) having a set (at least one) program module 924, including but not limited to: an operating system, one or more application programs, other program modules, and program data, each or some combination of these examples may include an implementation of a network environment.

[0123] The processor 91 executes various functional applications and data processing, such as the methods provided in any of the above embodiments, by running computer programs stored in the memory 92.

[0124] Electronic device 90 can also communicate with one or more external devices 94 (e.g., keyboard, pointing device, etc.). This communication can be performed via input / output (I / O) interface 95. Furthermore, the model-generated electronic device 90 can also communicate with one or more networks (e.g., local area network (LAN), wide area network (WAN), and / or public network, such as the Internet) via network adapter 96. As shown, network adapter 96 communicates with other modules of the model-generated electronic device 90 via bus 93. It should be understood that, although not shown in the figure, other hardware and / or software modules can be used in conjunction with the model-generated electronic device 90, including but not limited to: microcode, device drivers, redundant processors, external disk drive arrays, RAID (disk array) systems, tape drives, and data backup storage systems.

[0125] It should be noted that although several units / modules or sub-units / modules of the electronic device have been mentioned in the detailed description above, this division is merely exemplary and not mandatory. In fact, according to embodiments of the present invention, the features and functions of two or more units / modules described above can be embodied in one unit / module. Conversely, the features and functions of one unit / module described above can be further divided and embodied by multiple units / modules.

[0126] This invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method provided in any of the above embodiments.

[0127] The readable storage medium may be more specifically adopted, including but not limited to: portable disk, hard disk, random access memory, read-only memory, erasable programmable read-only memory, optical storage device, magnetic storage device, or any suitable combination thereof.

[0128] In a possible implementation, the present invention can also be implemented as a program product comprising program code, wherein when the program product is run on a terminal device, the program code is used to cause the terminal device to execute the method implementing any of the above embodiments.

[0129] The program code for executing the present invention can be written in any combination of one or more programming languages. The program code can be executed entirely on the user device, partially on the user device, as a standalone software package, partially on the user device and partially on a remote device, or entirely on a remote device.

[0130] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A method for diagnosing rotor bar breakage faults in a squirrel-cage induction motor, characterized in that, The rotor bar breakage fault diagnosis method includes: During the process of injecting a voltage of the target frequency into one phase winding of the squirrel-cage induction motor, the response current of the winding and the corresponding mechanical position angle are obtained; wherein, before the voltage is injected, the squirrel-cage induction motor is in an unloaded state, and the rotor of the squirrel-cage induction motor rotates at a set speed; The peak-to-peak value of the current is determined based on the response current, and the correlation between the peak-to-peak value of the current and the mechanical position angle is determined. The response current is interpolated based on the correlation to obtain the reconstructed current; Fault features are extracted from the reconstructed current, and rotor bar breakage fault diagnosis is performed based on the fault features; Determining the peak-to-peak value of the current based on the response current includes: Take the response current collected during the last mechanical cycle of the shutdown process from the response current; The difference between the upper and lower envelope signals of the response current is determined as the peak-to-peak value of the current.

2. The rotor bar breakage fault diagnosis method according to claim 1, characterized in that, Extracting fault features from the reconstructed current includes: Extract the DC component and the harmonic amplitude of the nth harmonic from the reconstructed current; The fault characteristics are determined based on the harmonic amplitude and the DC component.

3. The rotor bar breakage fault diagnosis method according to claim 2, characterized in that, Determining fault characteristics based on the harmonic amplitude and the DC component includes: The harmonic amplitude and the DC component are normalized. The fault characteristics are determined based on the normalized harmonic amplitude and DC component.

4. A rotor bar breakage fault diagnosis device for a squirrel-cage induction motor, characterized in that, The rotor bar breakage fault diagnosis device includes: The acquisition module is used to acquire the response current and corresponding mechanical position angle of the winding during the process of injecting a voltage of the target frequency into one phase winding of the squirrel-cage asynchronous motor; wherein, before the voltage is injected, the squirrel-cage asynchronous motor is in an unloaded state and the rotor of the squirrel-cage asynchronous motor rotates at a set speed; The determination module is used to determine the peak-to-peak value of the current based on the response current, and to determine the correlation between the peak-to-peak value of the current and the mechanical position angle; The reconstruction module is used to interpolate the response current according to the correlation to obtain the reconstructed current; The fault diagnosis module is used to extract fault features from the reconstructed current and perform rotor bar breakage fault diagnosis based on the fault features. The determining module includes: An extraction unit is used to extract the response current collected during the last mechanical cycle of the shutdown process from the response current; The determining unit determines the difference between the upper envelope signal and the lower envelope signal of the response current as the peak-to-peak value of the current.

5. The rotor bar breakage fault diagnosis device according to claim 4, characterized in that, The fault diagnosis module includes: An extraction unit is used to extract the DC component and the harmonic amplitude of the nth harmonic from the reconstructed current. The determination unit determines the fault characteristics based on the harmonic amplitude and the DC component.

6. The rotor bar breakage fault diagnosis device according to claim 5, characterized in that, The fault diagnosis module also includes: The processing unit is used to normalize the harmonic amplitude and the DC component. The diagnostic unit is used to determine the fault characteristics based on the normalized harmonic amplitude and the DC component.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and for running on the processor, characterized in that, When the processor executes the computer program, it implements the rotor bar breakage fault diagnosis method of the motor according to any one of claims 1 to 3.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the rotor bar breakage fault diagnosis method of the motor according to any one of claims 1 to 3.

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