Asynchronous motor turn-to-turn short circuit fault diagnosis method and system based on Park vector method
By Park transforming the three-phase current signal of the asynchronous motor and extracting the Park vector distance ratio, the problem of difficulty in quantitative evaluation of inter-turn short-circuit faults in the prior art is solved, accurate identification of faults and early warning are achieved, and the safety and reliability of the motor are improved.
Patent Information
- Application Number
- CN202411653809.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-19
- Publication Date
- 2025-05-02
AI Technical Summary
The prior art is difficult to effectively quantify the severity of asynchronous motor interturn short circuit failures, and the diagnostic accuracy and robustness are insufficient in complex industrial environments.
By performing Park transformation on the motor's three-phase current signal, the Park vector distance ratio is extracted as the fault feature, and combining mathematical transformation and fitting relationships, quantitative diagnosis of inter-turn short-circuit faults is achieved.
Accurate identification and quantitative evaluation of asynchronous motor interturn short circuit faults is achieved, which can provide early warnings in the early stages of failure, improve the safety and reliability of motor operation, and reduce losses caused by failures.
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Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of fault diagnosis of asynchronous motor turn-to-turn short circuit, and in particular to an asynchronous motor turn-to-turn short circuit fault diagnosis method and system based on Park vector method. Background Art
[0002] The inter-turn short circuit fault of asynchronous motor is one of the common motor faults in industry. Its hazards include local overheating, reduced efficiency, increased vibration and noise, and in severe cases, it can cause motor damage. The current fault diagnosis methods are divided into two categories: those based on vibration signals and current signals. The former is easily affected by the environment, while the method based on stator current signals has become a research hotspot in recent years.
[0003] Early diagnostic methods such as spectrum analysis and wavelet analysis faced the difficulty of extracting fault characteristic frequencies. For this reason, a diagnostic method based on Park vector was proposed. By converting the three-phase current signal of the motor into a dq coordinate system, the Park vector trajectory of a normal motor is approximately a circle, while the inter-turn short circuit fault causes the trajectory to be distorted into an ellipse or other closed curve. This method effectively avoids the limitations of frequency domain analysis, but it can only determine whether a fault has occurred, and cannot quantitatively evaluate the severity of the fault. To solve this problem, the researchers introduced the "Park vector distance ratio" as a fault feature, and quantitatively evaluated the severity of the fault by calculating the ratio of the distance between the two farthest points on the trajectory to the minimum inscribed circle radius. Experiments show that as the fault worsens, the Park vector distance ratio shows a significant growth trend, which can sensitively reflect the occurrence of the fault in the early stage of the fault.
[0004] However, the Park vector method may be disturbed by rotor or inverter faults. Future research should focus on improving the accuracy and robustness of diagnosis and combining it with other signal processing methods to cope with complex industrial environments.
[0005] In summary, the asynchronous motor inter-turn short-circuit fault diagnosis method and system based on the Park vector method mainly solves the technical problem of the lack of effective quantitative fault assessment in the existing technology; by mathematically transforming the three-phase current signal of the motor, a quantitative feature of "Park vector distance ratio" is proposed, which can effectively distinguish normal motors from faulty motors and quantitatively evaluate the severity of the fault; it not only overcomes the difficulty of extracting fault characteristic frequency in the frequency domain analysis method, but also can provide early warning in the early stage of the fault, thereby solving the technical problem that the existing technology cannot perform early diagnosis of inter-turn short-circuit faults and quantify the severity. Summary of the invention
[0006] In view of the above problems existing in the prior art, the present invention is proposed.
[0007] Therefore, the technical problem to be solved by the present invention is: through mathematical transformation and extraction of features such as "Park vector distance ratio", turn-to-turn short-circuit faults can be accurately identified, and the severity of the fault can be quantitatively evaluated to achieve early warning of the fault, thereby improving the safety and reliability of the operation of the asynchronous motor and reducing the losses caused by the fault.
[0008] To solve the above technical problems, the present invention provides the following technical solutions: a method for diagnosing an asynchronous motor turn-to-turn short-circuit fault based on the Park vector method, comprising: analyzing the three-phase current signal of the motor and selecting to perform mathematical transformation on the stator current signal; extracting features related to the turn-to-turn short-circuit fault from the vector trajectory of the mathematical transformation; fitting the feature information with the fault severity to obtain a quantitative diagnostic index; and performing fault diagnosis based on the extracted fault features and the fitting relationship.
[0009] As a preferred solution of the asynchronous motor inter-turn short-circuit fault diagnosis method based on the Park vector method described in the present invention, the mathematical transformation includes a Park transformation method, which uses the Park vector method to amplify and observe the degree of asymmetry of the three items of stator current through Park transformation to determine whether the motor has an inter-turn short-circuit fault.
[0010] As a preferred solution of the asynchronous motor inter-turn short-circuit fault diagnosis method based on the Park vector method described in the present invention, wherein: the vector trajectory of the mathematical transformation includes the Park vector trajectory of the healthy motor and the Park vector trajectory of the short-circuited motor.
[0011] As a preferred solution of the asynchronous motor inter-turn short circuit fault diagnosis method based on the Park vector method described in the present invention, the quantitative diagnostic index is defined as the "Park vector distance ratio" as the ratio of the distance between the two farthest points on the Park vector trajectory diagram to the radius of the minimum inscribed circle with the center of the trajectory diagram as the center.
[0012] As a preferred solution of the asynchronous motor inter-turn short circuit fault diagnosis method based on the Park vector method described in the present invention, wherein: the fault diagnosis, the asynchronous motor inter-turn short circuit diagnosis method based on the Park vector method and the "Park vector distance ratio" are used as the fault feature diagnosis.
[0013] As a preferred solution of the asynchronous motor inter-turn short circuit fault diagnosis method based on the Park vector method described in the present invention, wherein: the Park transformation method obtains the three-phase current signal generated during the operation of the motor, and simplifies the signal analysis and feature extraction through the Park transformation matrix; the trajectory image of the dq coordinate system is obtained through the Park transformation matrix transformation, and the normal motor and the faulty motor are distinguished according to the shape of the trajectory image; and the key features are extracted from the trajectory after the Park transformation to evaluate the severity of the fault.
[0014] As a preferred solution of the asynchronous motor inter-turn short circuit fault diagnosis method based on the Park vector method described in the present invention, wherein: the Park vector trajectory of the healthy motor, in normal operation, the trajectory of the motor stator current in the dq coordinate system is represented as a circle;
[0015] The Park vector trajectory of the short-circuited motor includes distortions to the healthy motor vector diagram, depending on the nature of the fault and the severity of the fault.
[0016] Another object of the present invention is to provide an asynchronous motor turn-to-turn short-circuit fault diagnosis system based on the Park vector method, which can extract fault characteristics and perform quantitative analysis by real-time monitoring of the three-phase current signal of the motor, thereby realizing classified diagnosis of different types of faults and distinguishing the severity of the faults, thereby optimizing maintenance decisions and reducing equipment downtime and maintenance costs.
[0017] In order to solve the above technical problems, the present invention provides the following technical solutions: an asynchronous motor turn-to-turn short circuit fault diagnosis system based on Park vector method, comprising: a signal analysis module, a mathematical transformation module, a feature extraction module and a fault diagnosis module;
[0018] The signal analysis module selects to perform mathematical transformation on the stator current signal by analyzing the three-phase current signal of the motor;
[0019] The mathematical transformation module extracts features related to the turn-to-turn short circuit fault from the vector trajectory of the mathematical transformation;
[0020] The feature extraction module fits the feature information with the fault severity to obtain a quantitative diagnostic index;
[0021] The fault diagnosis module performs fault diagnosis based on the extracted fault features and fitting relationships.
[0022] A computer device comprises a memory and a processor, wherein the memory stores a computer program, and is characterized in that when the processor executes the computer program, the steps of the asynchronous motor inter-turn short circuit fault diagnosis method based on the Park vector method as described above are implemented.
[0023] A computer-readable storage medium having a computer program stored thereon, characterized in that when the computer program is executed by a processor, the steps of the asynchronous motor turn-to-turn short-circuit fault diagnosis method based on the Park vector method as described above are implemented.
[0024] The beneficial effects of the present invention are as follows: it is robust to various rotor types and different stator winding forms and has a wide range of applications; the proposed fault characteristics and diagnostic methods are completely based on the stator three-phase current data and do not require other data types; compared with the traditional motor diagnostic method based on vibration data, the stator current signal can better reflect the properties of the motor itself and is not easily affected by the external environment; the proposed fault characteristics can respond to turn-to-turn short-circuit faults in the early stages, thereby providing earlier fault warnings. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.
[0026] Figure 1 A flow chart of a method for diagnosing an asynchronous motor turn-to-turn short-circuit fault based on the Park vector method is provided as an embodiment of the present invention.
[0027] Figure 2 A Park vector diagram of a healthy motor of an asynchronous motor turn-to-turn short circuit fault diagnosis method based on the Park vector method provided by an embodiment of the present invention.
[0028] Figure 3 A Park vector diagram of a simulated faulty motor with a short circuit ratio of 10% is provided for an asynchronous motor interturn short circuit fault diagnosis method based on the Park vector method according to an embodiment of the present invention.
[0029] Figure 4 A Park vector diagram of a healthy motor under normal operating conditions of an asynchronous motor turn-to-turn short-circuit fault diagnosis method based on the Park vector method provided by an embodiment of the present invention.
[0030] Figure 5 A Park vector diagram of a faulty motor with a short circuit ratio of 10% under normal operating conditions of an asynchronous motor turn-to-turn short circuit fault diagnosis method based on the Park vector method provided by an embodiment of the present invention.
[0031] Figure 6 A Park vector diagram of a faulty motor with a short circuit ratio of 17% under normal operating conditions of an asynchronous motor turn-to-turn short circuit fault diagnosis method based on the Park vector method provided by an embodiment of the present invention.
[0032] Figure 7 A Dmax and rmin diagram of a healthy motor under normal operating conditions of an asynchronous motor turn-to-turn short-circuit fault diagnosis method based on the Park vector method provided in one embodiment of the present invention.
[0033] Figure 8 A diagram showing the least squares fitting results of an asynchronous motor turn-to-turn short-circuit fault diagnosis method based on the Park vector method provided in one embodiment of the present invention. DETAILED DESCRIPTION
[0034] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.
[0035] Example 1, reference Figure 1 , is an embodiment of the present invention, which provides an asynchronous motor turn-to-turn short circuit fault diagnosis method based on Park vector method, comprising:
[0036] By analyzing the three-phase current signal of the motor, a mathematical transformation is selected for the stator current signal;
[0037] Extracting features related to turn-to-turn short-circuit faults from mathematically transformed vector trajectories;
[0038] Fit the characteristic information with the fault severity to obtain quantitative diagnostic indicators;
[0039] Fault diagnosis is performed based on the extracted fault features and fitting relationships.
[0040] Furthermore, the output of the three-phase current signal under normal operating conditions is a sine wave. When a turn-to-turn short-circuit fault occurs, the current signal will show imbalance and distortion. By accurately acquiring and processing the current signal, signs of internal motor faults can be revealed. After obtaining the current signal, the Park transform method is used to convert the three-phase current signal into a form that is easier to analyze, that is, the three-phase current is mapped to a dq coordinate system, which can eliminate the phase change of the three-phase AC signal and make the current signal present a more intuitive form in the time domain. For a healthy motor, the trajectory of the Park vector is approximately a perfect circle, but in the event of a turn-to-turn short-circuit fault, the trajectory will be significantly distorted and become similar to an ellipse or other irregular shapes.
[0041] Furthermore, after the Park transform, the features related to the turn-to-turn short-circuit fault are extracted from the generated Park vector trajectory, namely the "Park vector distance ratio". This feature quantifies the severity of the motor turn-to-turn short-circuit fault by calculating the ratio of the distance between the two farthest points in the vector trajectory to the minimum inscribed circle radius. By capturing the changes in the fault signal, it provides a quantitative basis and can accurately identify the fault at different stages. After extracting the features, these features are fitted with the severity of the fault to obtain quantitative diagnostic indicators. By analyzing the change pattern of the Park vector distance ratio, it can be directly associated with the severity of the fault.
[0042] Example 2, reference Figure 2-Figure 3 , is an embodiment of the present invention, which provides an asynchronous motor turn-to-turn short circuit fault diagnosis method based on Park vector method, comprising:
[0043] S1: By analyzing the three-phase current signal of the motor, select to perform mathematical transformation on the stator current signal.
[0044] It should be noted that the mathematical transformation includes the Park transformation method and the Park vector method which uses the Park transformation to amplify and observe the degree of asymmetry of the three items of stator current to determine whether a turn-to-turn short circuit fault occurs in the motor.
[0045] Furthermore, the Park transform method is used to obtain the three-phase current signal generated during the operation of the motor, and the signal analysis and feature extraction are simplified through the Park transform matrix. The trajectory image of the dq coordinate system is obtained through the Park transform matrix, and the normal motor and the faulty motor are distinguished according to the shape of the trajectory image; and key features are extracted from the trajectory after Park transform to evaluate the severity of the fault.
[0046] Furthermore, assume that the three-phase current of the motor is as follows:
[0047]
[0048] Among them, I m represents the amplitude of the phase current, Indicates the power factor angle of the phase current;
[0049] Take the equal power Park transformation matrix P:
[0050]
[0051] in:
[0052] P 11 =cos(1-s)ω0t
[0053] P 12 =cos[(1-s)ω0t-120°]
[0054] P 13 =cos[(1-s)ω0t+120°]
[0055] P 21 =-sin(1-s)ω0t
[0056] P 22 = -sin[(1-s)ω0t-120°]
[0057] P 23 = -sin[(1-s)ω0t+120°]
[0058] Where s represents the conversion rate of the motor; if it is an equal-amplitude Park transformation matrix, the coefficient of the transformation matrix in the transformation matrix P is 2 / 3;
[0059] Perform Park transformation on the three-phase current of the asynchronous motor, that is, multiply the transformation matrix P on the left, which is expressed as:
[0060]
[0061] We can get:
[0062]
[0063] S2: Extracting features related to turn-to-turn short-circuit faults from the mathematically transformed vector trajectory.
[0064] It should be noted that the vector trajectory of the mathematical transformation includes the Park vector trajectory of the healthy motor and the Park vector trajectory of the short-circuited motor.
[0065] Furthermore, the Park vector trajectory of a healthy motor is represented as a circle when the motor stator current is in normal operation in the dq coordinate system; the Park vector trajectory of a short-circuited motor includes distortions to the healthy motor vector diagram, depending on the nature of the fault and the severity of the fault.
[0066] Furthermore, the three-phase current amplitude I m is a constant value, then the trajectory of the motor stator current in the dq coordinate system during normal operation is a circle; however, due to the asymmetry of the motor itself and the asymmetry of the three-phase power supply, the Park vector trajectory diagram of a healthy motor under actual conditions is a polygon that approximates a circle, such as Figure 2 As shown in Figure 2, if any of the three phases ABC has a short circuit fault, the three-phase current amplitude I m The size of the short-circuited phase changes; generally speaking, the current amplitude of the short-circuited phase will increase, causing the Park vector trajectory diagram, which is close to a circle, to be distorted. The distorted image is close to an ellipse or other closed curve because the three-phase current is no longer balanced, such as Figure 3 As shown, the specific shape depends on the nature of the fault and the severity of the fault.
[0067] S3: Fit the characteristic information with the fault severity to obtain quantitative diagnostic indicators.
[0068] It should be noted that the quantitative diagnostic index, the ratio of the distance between the two farthest points on the Park vector trajectory diagram and the radius of the smallest inscribed circle with the center of the trajectory diagram as the center, is defined as the “Park vector distance ratio”;
[0069] Furthermore, the distance D between the two farthest points on the Park vector trajectory is defined as max The radius r of the minimum inscribed circle with the center of the trajectory diagram as the center min Ratio P r is the Park vector distance ratio, expressed as:
[0070]
[0071] S4: Perform fault diagnosis based on the extracted fault features and fitting relationships.
[0072] It should be noted that the fault diagnosis, the diagnosis method of the short circuit between turns of the asynchronous motor based on the Park vector method and the diagnosis of the "Park vector distance ratio" as the fault feature;
[0073] Furthermore, the feasibility of diagnosing the short-circuit fault of the asynchronous motor between turns is investigated by using the property that the short-circuit fault between turns of the stator winding of the three-phase asynchronous motor will cause the Park vector diagram to be distorted from a polygon similar to a circle to a closed curve similar to an ellipse; the severity of the short-circuit fault between turns is measured by the quantitative fault feature "Park vector distance ratio"; the higher the severity of the fault, the higher the imbalance of the three-phase current, and the greater the Park vector distance ratio; and the corresponding relationship function between the two is fitted using the least squares method for quantitative diagnosis; in order to determine whether the short-circuit ratio of the short-circuited motor is due to rotor fault (such as rotor The magnetic field changes caused by the motor inverter and the motor stator terminal are connected, so the inverter open circuit or short circuit fault will also cause the stator three-phase current imbalance; most modern gate drivers have a desaturation protection mechanism (DESAT) that can prevent short circuit problems, and the DESAT mechanism can identify the current imbalance caused by the inverter short circuit or open circuit fault, so the inter-turn short circuit fault can be distinguished from the inverter fault.
[0074] The above is a schematic scheme of an asynchronous motor turn-to-turn short-circuit fault diagnosis method based on the Park vector method in this embodiment. It should be noted that the technical scheme of the system of the asynchronous motor turn-to-turn short-circuit fault diagnosis method based on the Park vector method and the technical scheme of the asynchronous motor turn-to-turn short-circuit fault diagnosis method based on the Park vector method belong to the same concept, and the details of the technical scheme of the asynchronous motor turn-to-turn short-circuit fault diagnosis system based on the Park vector method in this embodiment that are not described in detail can all be referred to the description of the technical scheme of the asynchronous motor turn-to-turn short-circuit fault diagnosis method based on the Park vector method.
[0075] Example 3, with reference to FIG. Figure 4-Figure 8 An embodiment of the present invention provides an asynchronous motor turn-to-turn short-circuit fault diagnosis method based on the Park vector method. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through economic benefit calculation and simulation experiments.
[0076] A 1.1kw motor (ABB, M2QA90L2A, 2850RPM) was used to test the stator windings for 5%, 10%, 12%, 15%, 17% inter-turn short circuit faults and the motor in healthy condition. The results are as follows: Figure 4 , Figure 5 As shown, Figure 4 This is the Park vector diagram of this type of asynchronous motor in normal operation. Figure 5 This is the Park vector diagram of this type of asynchronous motor with a short circuit ratio of 10%. Figure 6 This is the Park vector diagram of this model motor with an inter-turn short circuit fault with a short circuit ratio of 17%; the sampling frequency is 10k, the stator current frequency is 20hz, and the short circuit ratio is defined as the number of coil turns with short circuit fault divided by the total number of coil turns multiplied by 100%.
[0077] Depend on Figure 4 , Figure 5 , Figure 6 It can be seen that:
[0078] After an inter-turn short circuit occurs in an asynchronous motor, its Park vector diagram will be distorted, from the original polygonal shape that is approximately circular to a closed shape that is approximately elliptical. It can be judged that an inter-turn short circuit fault has occurred.
[0079] As the fault severity increases, that is, the short-circuit ratio increases, the Park vector diagram of the motor becomes more "flat". This is due to the increasing degree of three-phase imbalance caused by the inter-turn short-circuit fault. This property can be used to find the fault characteristic quantity that quantitatively describes the severity of the motor fault.
[0080] The Park distance ratio (PDR) is extracted for the motor with 5%, 10%, 12%, 15%, 17% inter-turn short circuit fault and healthy state. That is, the distance D between the two farthest points on the contour of the Park vector trajectory is calculated. max The radius r of the minimum inscribed circle with the center of the trajectory diagram as the center min The result is as follows Figure 7 As shown in Table 1 below;
[0081] Table 1 PDR under different fault severity
[0082] FaultDegree Healthy 5％ 10％ 12％ 15％ 17％ PDR 2.14 7.27 7.44 7.58 8.47 9.51
[0083] Among them, the PDR data in the table is the average value after obtaining data from 10 experiments.
[0084] As the severity of the fault increases, the motor performance decreases, and the PDR data also increases. The specific corresponding relationship is fitted using the least squares method, and the results are as follows: Figure 8 As shown;
[0085] The specific mathematical expression of the corresponding relationship between the fitted PDR and fault severity is:
[0086] f(x)=p1*x 3 +p2*x 3 +p3*x+p4
[0087] in:
[0088] p1=0.007024
[0089] p2=-0.191
[0090] p3=1.779
[0091] p4=2.16
[0092] Another set of healthy motors with a current frequency of 20 Hz under normal operating conditions were used for verification, and the stator current data of this model motor with 5%, 10%, 12%, 15%, and 17% of the current occurred. The verification results after taking the average value are shown in Table 2 below;
[0093] Table 2 PDR under different fault severity under verification data
[0094] FaultDegree Healthy 5％ 10％ 12％ 15％ 17％ PDR 2.13 6.86 7.50 7.53 8.61 9.58
[0095] Among them, the PDR data in the table is the average value after obtaining data from 10 experiments.
[0096] Substituting the above results into the specific mathematical expression of the corresponding relationship between the fitted PDR and the fault severity, discarding the unreasonable results, the prediction results obtained are shown in Table 3:
[0097] Table 3 Predicted short circuit percentage values of different PDRs under fitting functions
[0098]
[0099] It can be seen that as a fault feature, PDR and the fitted function relationship can accurately predict the severity of the fault. And even if the short circuit ratio is small after the short circuit fault occurs, that is, the fault is in the early stage, the change in PDR is still obvious, which means that PDR as a fault feature can respond to the early stage of the inter-turn short circuit fault, so that early warning can be given.
[0100] Embodiment 4 is an embodiment of the present invention, which provides an asynchronous motor turn-to-turn short circuit fault diagnosis system based on Park vector method, including: a signal analysis module, a mathematical transformation module, a feature extraction module and a fault diagnosis module;
[0101] The signal analysis module selects to perform mathematical transformation on the stator current signal by analyzing the three-phase current signal of the motor;
[0102] The mathematical transformation module extracts features related to the turn-to-turn short circuit fault from the vector trajectory of the mathematical transformation;
[0103] The feature extraction module fits the feature information with the fault severity to obtain a quantitative diagnostic index;
[0104] The fault diagnosis module performs fault diagnosis based on the extracted fault features and fitting relationships.
[0105] This embodiment further provides a computing device, which is applicable to the case of an asynchronous motor turn-to-turn short circuit fault diagnosis method based on the Park vector method, and includes:
[0106] Memory and processor; the memory is used to store computer executable instructions, and the processor is used to execute computer executable instructions to implement the asynchronous motor turn-to-turn short circuit fault diagnosis method based on the Park vector method as proposed in the above embodiment.
[0107] This embodiment further provides a storage medium on which a computer program is stored. When the program is executed by a processor, the method for diagnosing the inter-turn short-circuit fault of an asynchronous motor based on the Park vector method as proposed in the above embodiment is implemented.
[0108] The storage medium proposed in this embodiment and the asynchronous motor turn-to-turn short-circuit fault diagnosis method based on the Park vector method proposed in the above embodiment belong to the same inventive concept. The technical details not described in detail in this embodiment can be referred to the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.
[0109] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.
[0110] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.
[0111] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.
[0112] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.
Claims
1. A method for diagnosing inter-turn short-circuit fault of an asynchronous motor based on Park vector method, characterized in that: include: By analyzing the three-phase current signal of the motor, a mathematical transformation is selected for the stator current signal; Extracting features related to turn-to-turn short-circuit faults from mathematically transformed vector trajectories; Fit the characteristic information with the fault severity to obtain quantitative diagnostic indicators; Fault diagnosis is performed based on the extracted fault features and fitting relationships.
2. The method for diagnosing an asynchronous motor turn-to-turn short circuit fault based on the Park vector method according to claim 1, characterized in that: The mathematical transformation includes a Park transformation method and a Park vector method for determining whether a turn-to-turn short circuit fault occurs in the motor by amplifying and observing the asymmetry degree of three items of stator current through Park transformation.
3. The method for diagnosing an asynchronous motor turn-to-turn short-circuit fault based on the Park vector method as claimed in claim 2, characterized in that: The vector trajectory of the mathematical transformation includes a Park vector trajectory of a healthy motor and a Park vector trajectory of a short-circuited motor.
4. The method for diagnosing an asynchronous motor turn-to-turn short-circuit fault based on the Park vector method as claimed in claim 3, characterized in that: The quantitative diagnostic index is defined as the ratio of the distance between the two farthest points on the Park vector trajectory diagram to the radius of the smallest inscribed circle with the center of the trajectory diagram as the center as the "Park vector distance ratio".
5. The method for diagnosing an asynchronous motor turn-to-turn short-circuit fault based on the Park vector method as claimed in claim 4, characterized in that: The fault diagnosis is based on the Park vector method for diagnosing short circuits between turns of an asynchronous motor and the use of "Park vector distance ratio" as a fault feature.
6. The method for diagnosing an asynchronous motor turn-to-turn short-circuit fault based on the Park vector method as claimed in claim 5, characterized in that: The Park transformation method obtains the three-phase current signal generated during the operation of the motor and simplifies the signal analysis and feature extraction through the Park transformation matrix; The trajectory image of the dq coordinate system is obtained through Park transformation matrix transformation. According to the shape of the trajectory image, the normal motor and the faulty motor are distinguished; and the key features are extracted from the trajectory after Park transformation to evaluate the severity of the fault.
7. The method for diagnosing an asynchronous motor turn-to-turn short-circuit fault based on the Park vector method according to claim 6, characterized in that: The Park vector trajectory of the healthy motor is represented as a circle when the motor stator current is in normal operation in the dq coordinate system; The Park vector trajectory of the short-circuited motor includes distortions to the healthy motor vector diagram, depending on the nature of the fault and the severity of the fault.
8. A system for diagnosing turn-to-turn short-circuit faults of asynchronous motors based on the Park vector method according to any one of claims 1 to 7, characterized in that: include: Signal analysis module, mathematical transformation module, feature extraction module and fault diagnosis module; The signal analysis module selects to perform mathematical transformation on the stator current signal by analyzing the three-phase current signal of the motor; The mathematical transformation module extracts features related to the turn-to-turn short circuit fault from the vector trajectory of the mathematical transformation; The feature extraction module fits the feature information with the fault severity to obtain a quantitative diagnostic index; The fault diagnosis module performs fault diagnosis based on the extracted fault features and fitting relationships.
9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the asynchronous motor turn-to-turn short-circuit fault diagnosis method based on the Park vector method described in any one of claims 1 to 7 are implemented.
10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the asynchronous motor turn-to-turn short-circuit fault diagnosis method based on the Park vector method described in any one of claims 1 to 7 are implemented.