Fault diagnosis method and system for traction motor

Abstract

The invention provides a fault diagnosis method and system for a traction motor, and the method comprises the steps: obtaining a motor current fluctuation amplitude, a motor rotating speed fluctuation amplitude and a motor voltage fluctuation amplitude through injecting harmonic current, carrying out the curved surface fitting, obtaining a fitting curved surface, injecting the harmonic current during fault diagnosis, obtaining the real-time fluctuation amplitude, and carrying out the fault diagnosis. And after corresponding fluctuation amplitudes are obtained based on the fitting curved surface, comparison is carried out respectively, and if any fluctuation amplitude is inconsistent, it is considered that the traction motor has a fault. According to the method, the harmonic current and the curved surface fitting method are used for carrying out traction motor fault diagnosis, fault diagnosis can be carried out from multiple dimensions, and the diagnosis accuracy and reliability are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of motor fault diagnosis, and in particular to a traction motor fault diagnosis method and system. Background Art

[0002] Traction motors are widely used, such as traction motors on railway mainline electric locomotives, industrial and mining electric locomotives, electric transmission diesel locomotives and various electric vehicles (such as battery vehicles, new energy vehicles, urban trams, subway electric vehicles). Traction motors include traction motors, traction generators, auxiliary motors, etc.

[0003] There are many methods for traction motor fault diagnosis, and the application of these methods helps to timely detect and deal with motor faults to ensure its normal operation. Common traction motor fault diagnosis methods include: current analysis method, vibration detection method, temperature monitoring method, vibration and sound diagnosis technology, special electrical experimental diagnosis technology, stator current method and direct observation method, etc. However, these methods are all fault diagnosis from a single dimension, which makes the diagnosis not precise and effective, and has low accuracy and reliability. Summary of the invention

[0004] The present invention provides a traction motor fault diagnosis method and system, which perform fault diagnosis from multiple dimensions to improve the diagnosis accuracy and reliability.

[0005] This specification discloses a method for diagnosing a fault of a traction motor, comprising:

[0006] Based on different motor currents, different and / or the same harmonic currents are injected into the traction power supply system of the traction motor, and the fluctuation amplitudes of the motor currents caused thereby are measured respectively, which are recorded as the motor current fluctuation amplitudes;

[0007] Based on different motor speeds, different and / or the same harmonic currents are injected into the traction power supply system of the traction motor, and the fluctuation amplitudes of the motor speeds caused by the changes are measured respectively, which are recorded as the motor speed fluctuation amplitudes;

[0008] Based on different motor voltages, different and / or the same harmonic currents are injected into the traction power supply system of the traction motor, and the fluctuation amplitude of the motor voltage caused thereby is measured, which is recorded as the motor voltage fluctuation amplitude;

[0009] The motor current is used as a row vector, the harmonic current is used as a column vector, a matrix is ​​constructed, and then the motor current fluctuation amplitude is imported, and a surface fitting operation is performed to obtain a first fitting surface;

[0010] The motor speed is used as a row vector and the harmonic current is used as a column vector to form a matrix, and then the motor speed fluctuation amplitude is introduced to perform a surface fitting operation to obtain a second fitting surface;

[0011] The motor voltage is used as a row vector, the harmonic current is used as a column vector, a matrix is ​​constructed, and then the motor voltage fluctuation amplitude is imported, and a surface fitting operation is performed to obtain a third fitting surface;

[0012] During fault diagnosis, harmonic current is injected into the traction power supply system of the traction motor to obtain real-time motor current, real-time motor speed and real-time motor voltage, and the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude and real-time motor voltage fluctuation amplitude are measured. Based on the injected harmonic current, real-time motor current, real-time motor speed, real-time motor voltage, the first fitting surface, the second fitting surface and the third fitting surface, the corresponding motor current fluctuation amplitude, motor speed fluctuation amplitude and motor voltage fluctuation amplitude are obtained respectively, and compared with the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude and real-time motor voltage fluctuation amplitude respectively. If any of the fluctuation amplitudes are inconsistent, it is considered that the traction motor has a fault.

[0013] In this specification, based on different motor vibration frequencies, different and / or the same harmonic currents are injected into the traction power supply system of the traction motor, and the fluctuation amplitude of the motor vibration frequency caused by the change is measured respectively, which is recorded as the motor vibration frequency fluctuation amplitude;

[0014] The motor vibration frequency is used as a row vector, and the harmonic current is used as a column vector to form a matrix, and then the motor vibration frequency fluctuation amplitude is imported, and a surface fitting operation is performed to obtain a fourth fitting surface;

[0015] During fault diagnosis, harmonic current is injected into the traction power supply system of the traction motor to obtain real-time motor current, real-time motor speed, real-time motor voltage and real-time motor vibration frequency, and the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude, real-time motor voltage fluctuation amplitude and real-time motor vibration frequency fluctuation amplitude are measured. Based on the injected harmonic current, real-time motor current, real-time motor speed, real-time motor voltage, real-time motor vibration frequency, the first fitting surface, the second fitting surface, the third fitting surface and the fourth fitting surface, the corresponding motor current fluctuation amplitude, motor speed fluctuation amplitude, motor voltage fluctuation amplitude and motor vibration frequency fluctuation amplitude are obtained respectively, and compared with the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude, real-time motor voltage fluctuation amplitude and real-time motor vibration frequency fluctuation amplitude respectively. If any of the fluctuation amplitudes are inconsistent, it is considered that the traction motor has a fault.

[0016] In this specification, based on different motor temperatures, different and / or the same harmonic currents are injected into the traction power supply system of the traction motor, and the fluctuation amplitude of the motor temperature caused by the change is measured respectively, which is recorded as the motor temperature fluctuation amplitude;

[0017] The motor temperature is used as a row vector, the harmonic current is used as a column vector, a matrix is ​​constructed, and then the motor temperature fluctuation amplitude is imported, and a surface fitting operation is performed to obtain a fifth fitting surface;

[0018] During fault diagnosis, harmonic current is injected into the traction power supply system of the traction motor to obtain real-time motor current, real-time motor speed, real-time motor voltage and real-time motor temperature, and the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude, real-time motor voltage fluctuation amplitude and real-time motor temperature fluctuation amplitude are measured. Based on the injected harmonic current, real-time motor current, real-time motor speed, real-time motor voltage, real-time motor temperature, the first fitting surface, the second fitting surface, the third fitting surface and the fifth fitting surface, the corresponding motor current fluctuation amplitude, motor speed fluctuation amplitude, motor voltage fluctuation amplitude and motor temperature fluctuation amplitude are obtained respectively, and compared with the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude, real-time motor voltage fluctuation amplitude and real-time motor temperature fluctuation amplitude respectively. If any of the fluctuation amplitudes are inconsistent, it is considered that the traction motor has a fault.

[0019] In this specification, based on different motor working noises, different and / or the same harmonic currents are injected into the traction power supply system of the traction motor, and the fluctuation amplitude of the motor working noise caused by the changes is measured respectively, which is recorded as the motor working noise fluctuation amplitude;

[0020] The motor working noise is taken as a row vector, the harmonic current is taken as a column vector, a matrix is ​​constructed, and then the motor working noise fluctuation amplitude is imported, and a surface fitting operation is performed to obtain a sixth fitting surface;

[0021] During fault diagnosis, harmonic current is injected into the traction power supply system of the traction motor to obtain real-time motor current, real-time motor speed, real-time motor voltage and real-time motor operating noise, and the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude, real-time motor voltage fluctuation amplitude and real-time motor operating noise fluctuation amplitude are measured. Based on the injected harmonic current, real-time motor current, real-time motor speed, real-time motor voltage, real-time motor operating noise, the first fitting surface, the second fitting surface, the third fitting surface and the sixth fitting surface, the corresponding motor current fluctuation amplitude, motor speed fluctuation amplitude, motor voltage fluctuation amplitude and motor operating noise fluctuation amplitude are obtained respectively, and compared with the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude, real-time motor voltage fluctuation amplitude and real-time motor operating noise fluctuation amplitude respectively. If any of the fluctuation amplitudes are inconsistent, it is considered that the traction motor has a fault.

[0022] In this specification, based on different motor stator currents, different and / or the same harmonic currents are injected into the traction power supply system of the traction motor, and the fluctuation amplitude of the motor stator current caused by the changes is measured respectively, which is recorded as the motor stator current fluctuation amplitude;

[0023] The motor stator current is taken as a row vector, the harmonic current is taken as a column vector, a matrix is ​​constructed, and then the motor stator current fluctuation amplitude is imported, and a surface fitting operation is performed to obtain a seventh fitting surface;

[0024] During fault diagnosis, harmonic current is injected into the traction power supply system of the traction motor to obtain real-time motor current, real-time motor speed, real-time motor voltage and real-time motor stator current, and the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude, real-time motor voltage fluctuation amplitude and real-time motor stator current fluctuation amplitude are measured. Based on the injected harmonic current, real-time motor current, real-time motor speed, real-time motor voltage, real-time motor stator current, the first fitting surface, the second fitting surface, the third fitting surface and the seventh fitting surface, the corresponding motor current fluctuation amplitude, motor speed fluctuation amplitude, motor voltage fluctuation amplitude and motor stator current fluctuation amplitude are obtained respectively, and compared with the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude, real-time motor voltage fluctuation amplitude and real-time motor stator current fluctuation amplitude respectively. If any of the fluctuation amplitudes are inconsistent, it is considered that the traction motor has a fault.

[0025] In this specification, when diagnosing a fault, different harmonic currents are successively injected into the traction power supply system of the traction motor to obtain the corresponding real-time motor current, real-time motor speed and real-time motor voltage, and the corresponding real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude and real-time motor voltage fluctuation amplitude are measured. Based on the injected different harmonic currents, the corresponding real-time motor current, real-time motor speed and real-time motor voltage, as well as the first fitting surface, the second fitting surface and the third fitting surface, the corresponding motor current fluctuation amplitude, motor speed fluctuation amplitude and motor voltage fluctuation amplitude are respectively obtained, and compared with the corresponding real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude and real-time motor voltage fluctuation amplitude, respectively. If any of the fluctuation amplitudes are inconsistent, it is considered that the traction motor has a fault.

[0026] In this specification, different harmonic currents are injected into the traction power supply system of the traction motor, and the motor current is gradually increased or decreased, the harmonic voltage generated thereby is measured, and the harmonic impedance is calculated;

[0027] Based on the injected harmonic current, motor current and harmonic impedance, a surface fitting method is used to obtain the first harmonic impedance fitting surface;

[0028] When diagnosing a fault, a harmonic current is injected into the traction power supply system of the traction motor, the harmonic voltage generated thereby is measured, and the real-time harmonic impedance is calculated; and a harmonic impedance reference value is obtained based on the real-time injected harmonic current, the real-time motor current and the first harmonic impedance fitting surface;

[0029] The real-time harmonic impedance is compared with the harmonic impedance reference value. If they are inconsistent, and the motor current fluctuation amplitude obtained by the first fitting surface is inconsistent with the real-time motor current fluctuation amplitude, it is considered that the traction motor is faulty.

[0030] If the real-time harmonic impedance is consistent with the harmonic impedance reference value, and the motor current fluctuation amplitude obtained by the first fitting surface is consistent with the real-time motor current fluctuation amplitude, it is considered that the traction motor has no fault;

[0031] If either of the two conditions is inconsistent, it is considered that the traction motor may be faulty.

[0032] In this specification, different harmonic currents are injected into the traction power supply system of the traction motor, and the motor speed is gradually increased or decreased, the harmonic voltage generated thereby is measured, and the harmonic impedance is calculated;

[0033] Based on the injected harmonic current, motor speed and harmonic impedance, the surface fitting method is used to obtain the second harmonic impedance fitting surface;

[0034] When diagnosing a fault, a harmonic current is injected into the traction power supply system of the traction motor, the harmonic voltage generated thereby is measured, and the real-time harmonic impedance is calculated; and based on the real-time injected harmonic current, the real-time motor speed and the second harmonic impedance fitting surface, a harmonic impedance reference value is obtained;

[0035] The real-time harmonic impedance is compared with the harmonic impedance reference value. If they are inconsistent, and the motor speed fluctuation amplitude obtained by the second fitting surface is inconsistent with the real-time motor speed fluctuation amplitude, it is considered that the traction motor is faulty.

[0036] If the real-time harmonic impedance is consistent with the harmonic impedance reference value, and the motor speed fluctuation amplitude obtained by the second fitting surface is consistent with the real-time motor speed fluctuation amplitude, it is considered that the traction motor has no fault;

[0037] If either of the two conditions is inconsistent, it is considered that the traction motor may be faulty.

[0038] In this specification, different harmonic currents are injected into the traction power supply system of the traction motor, and the motor voltage is gradually increased or decreased, the harmonic voltage generated thereby is measured, and the harmonic impedance is calculated;

[0039] Based on the injected harmonic current, motor voltage and harmonic impedance, the third harmonic impedance fitting surface is obtained using the surface fitting method;

[0040] When diagnosing a fault, a harmonic current is injected into the traction power supply system of the traction motor, the harmonic voltage generated thereby is measured, and the real-time harmonic impedance is calculated; and a harmonic impedance reference value is obtained based on the real-time injected harmonic current, the real-time motor voltage and the third harmonic impedance fitting surface;

[0041] The real-time harmonic impedance is compared with the harmonic impedance reference value. If they are inconsistent, and the motor voltage fluctuation amplitude obtained by the third fitting surface is inconsistent with the real-time motor voltage fluctuation amplitude, it is considered that the traction motor is faulty.

[0042] If the real-time harmonic impedance is consistent with the harmonic impedance reference value, and the motor voltage fluctuation amplitude obtained by the third fitting surface is consistent with the real-time motor voltage fluctuation amplitude, it is considered that the traction motor has no fault;

[0043] If either of the two conditions is inconsistent, it is considered that the traction motor may be faulty.

[0044] This specification also discloses a traction motor fault diagnosis system, which is used to implement any one of the above-mentioned traction motor fault diagnosis methods, and the traction motor fault diagnosis system includes:

[0045] Data acquisition module, used to:

[0046] Based on different motor currents, different and / or the same harmonic currents are injected into the traction power supply system of the traction motor, and the fluctuation amplitudes of the motor currents caused thereby are measured respectively, which are recorded as the motor current fluctuation amplitudes;

[0047] Based on different motor speeds, different and / or the same harmonic currents are injected into the traction power supply system of the traction motor, and the fluctuation amplitudes of the motor speeds caused by the changes are measured respectively, which are recorded as the motor speed fluctuation amplitudes;

[0048] Based on different motor voltages, different and / or the same harmonic currents are injected into the traction power supply system of the traction motor, and the fluctuation amplitude of the motor voltage caused thereby is measured, which is recorded as the motor voltage fluctuation amplitude;

[0049] Surface fitting module for:

[0050] The motor current is used as a row vector, the harmonic current is used as a column vector, a matrix is ​​constructed, and then the motor current fluctuation amplitude is imported, and a surface fitting operation is performed to obtain a first fitting surface;

[0051] The motor speed is used as a row vector and the harmonic current is used as a column vector to form a matrix, and then the motor speed fluctuation amplitude is introduced to perform a surface fitting operation to obtain a second fitting surface;

[0052] The motor voltage is used as a row vector, the harmonic current is used as a column vector, a matrix is ​​constructed, and then the motor voltage fluctuation amplitude is imported, and a surface fitting operation is performed to obtain a third fitting surface;

[0053] The fault diagnosis module is used to inject harmonic current into the traction power supply system of the traction motor during fault diagnosis, obtain real-time motor current, real-time motor speed and real-time motor voltage, and measure the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude and real-time motor voltage fluctuation amplitude. Based on the injected harmonic current, real-time motor current, real-time motor speed, real-time motor voltage, the first fitting surface, the second fitting surface and the third fitting surface, the corresponding motor current fluctuation amplitude, motor speed fluctuation amplitude and motor voltage fluctuation amplitude are respectively obtained, and compared with the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude and real-time motor voltage fluctuation amplitude respectively. If any fluctuation amplitude is inconsistent, it is considered that the traction motor has a fault.

[0054] This manual can at least achieve the following beneficial effects:

[0055] By injecting harmonic current, the motor current fluctuation amplitude, motor speed fluctuation amplitude and motor voltage fluctuation amplitude are obtained, and then surface fitting is performed respectively to obtain the fitting surface. When diagnosing faults, harmonic current is injected to obtain the real-time fluctuation amplitude, and the corresponding fluctuation amplitude is obtained based on the fitting surface, and then compared respectively. If any fluctuation amplitude is inconsistent, it is considered that the traction motor is faulty. Using harmonic current and surface fitting methods for traction motor fault diagnosis, fault diagnosis can be performed from multiple dimensions, improving the accuracy and reliability of diagnosis. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] 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.

[0057] Figure 1 It is a flow chart of the fault diagnosis method of the traction motor involved in the present invention. DETAILED DESCRIPTION

[0058] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the embodiments of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0059] The disclosure below provides many different embodiments or examples to implement different structures of the embodiments of the present invention. In order to simplify the disclosure of the embodiments of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the embodiments of the present invention. In addition, the embodiments of the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed.

[0060] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0061] like Figure 1 As shown, this specification discloses a fault diagnosis method for a traction motor, comprising:

[0062] Based on different motor currents, different and / or the same harmonic currents are injected into the traction power supply system of the traction motor, and the fluctuation amplitudes of the motor currents caused thereby are measured respectively, which are recorded as the motor current fluctuation amplitudes;

[0063] Based on different motor speeds, different and / or the same harmonic currents are injected into the traction power supply system of the traction motor, and the fluctuation amplitudes of the motor speeds caused by the changes are measured respectively, which are recorded as the motor speed fluctuation amplitudes;

[0064] Based on different motor voltages, different and / or the same harmonic currents are injected into the traction power supply system of the traction motor, and the fluctuation amplitude of the motor voltage caused thereby is measured, which is recorded as the motor voltage fluctuation amplitude;

[0065] The motor current is used as a row vector, the harmonic current is used as a column vector, a matrix is ​​constructed, and then the motor current fluctuation amplitude is imported, and a surface fitting operation is performed to obtain a first fitting surface;

[0066] The motor speed is used as a row vector and the harmonic current is used as a column vector to form a matrix, and then the motor speed fluctuation amplitude is introduced to perform a surface fitting operation to obtain a second fitting surface;

[0067] The motor voltage is used as a row vector, the harmonic current is used as a column vector, a matrix is ​​constructed, and then the motor voltage fluctuation amplitude is imported, and a surface fitting operation is performed to obtain a third fitting surface;

[0068] During fault diagnosis, harmonic current is injected into the traction power supply system of the traction motor to obtain real-time motor current, real-time motor speed and real-time motor voltage, and the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude and real-time motor voltage fluctuation amplitude are measured. Based on the injected harmonic current, real-time motor current, real-time motor speed, real-time motor voltage, the first fitting surface, the second fitting surface and the third fitting surface, the corresponding motor current fluctuation amplitude, motor speed fluctuation amplitude and motor voltage fluctuation amplitude are obtained respectively, and compared with the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude and real-time motor voltage fluctuation amplitude respectively. If any of the fluctuation amplitudes are inconsistent, it is considered that the traction motor has a fault.

[0069] In some embodiments, based on different motor vibration frequencies, different and / or the same harmonic currents are injected into the traction power supply system of the traction motor, and the fluctuation amplitude of the motor vibration frequency caused by the change is measured respectively, which is recorded as the motor vibration frequency fluctuation amplitude;

[0070] The motor vibration frequency is used as a row vector, and the harmonic current is used as a column vector to form a matrix, and then the motor vibration frequency fluctuation amplitude is imported, and a surface fitting operation is performed to obtain a fourth fitting surface;

[0071] During fault diagnosis, harmonic current is injected into the traction power supply system of the traction motor to obtain real-time motor current, real-time motor speed, real-time motor voltage and real-time motor vibration frequency, and the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude, real-time motor voltage fluctuation amplitude and real-time motor vibration frequency fluctuation amplitude are measured. Based on the injected harmonic current, real-time motor current, real-time motor speed, real-time motor voltage, real-time motor vibration frequency, the first fitting surface, the second fitting surface, the third fitting surface and the fourth fitting surface, the corresponding motor current fluctuation amplitude, motor speed fluctuation amplitude, motor voltage fluctuation amplitude and motor vibration frequency fluctuation amplitude are obtained respectively, and compared with the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude, real-time motor voltage fluctuation amplitude and real-time motor vibration frequency fluctuation amplitude respectively. If any of the fluctuation amplitudes are inconsistent, it is considered that the traction motor has a fault.

[0072] In some embodiments, based on different motor temperatures, different and / or the same harmonic currents are injected into the traction power supply system of the traction motor, and the fluctuation amplitudes of the motor temperature changes caused thereby are measured respectively, which are recorded as the motor temperature fluctuation amplitudes;

[0073] The motor temperature is used as a row vector, the harmonic current is used as a column vector, a matrix is ​​constructed, and then the motor temperature fluctuation amplitude is imported, and a surface fitting operation is performed to obtain a fifth fitting surface;

[0074] During fault diagnosis, harmonic current is injected into the traction power supply system of the traction motor to obtain real-time motor current, real-time motor speed, real-time motor voltage and real-time motor temperature, and the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude, real-time motor voltage fluctuation amplitude and real-time motor temperature fluctuation amplitude are measured. Based on the injected harmonic current, real-time motor current, real-time motor speed, real-time motor voltage, real-time motor temperature, the first fitting surface, the second fitting surface, the third fitting surface and the fifth fitting surface, the corresponding motor current fluctuation amplitude, motor speed fluctuation amplitude, motor voltage fluctuation amplitude and motor temperature fluctuation amplitude are obtained respectively, and compared with the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude, real-time motor voltage fluctuation amplitude and real-time motor temperature fluctuation amplitude respectively. If any of the fluctuation amplitudes are inconsistent, it is considered that the traction motor has a fault.

[0075] In some embodiments, based on different motor working noises, different and / or the same harmonic currents are injected into the traction power supply system of the traction motor, and the fluctuation amplitude of the motor working noise caused by the changes is measured respectively, which is recorded as the motor working noise fluctuation amplitude;

[0076] The motor working noise is taken as a row vector, the harmonic current is taken as a column vector, a matrix is ​​constructed, and then the motor working noise fluctuation amplitude is imported, and a surface fitting operation is performed to obtain a sixth fitting surface;

[0077] During fault diagnosis, harmonic current is injected into the traction power supply system of the traction motor to obtain real-time motor current, real-time motor speed, real-time motor voltage and real-time motor operating noise, and the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude, real-time motor voltage fluctuation amplitude and real-time motor operating noise fluctuation amplitude are measured. Based on the injected harmonic current, real-time motor current, real-time motor speed, real-time motor voltage, real-time motor operating noise, the first fitting surface, the second fitting surface, the third fitting surface and the sixth fitting surface, the corresponding motor current fluctuation amplitude, motor speed fluctuation amplitude, motor voltage fluctuation amplitude and motor operating noise fluctuation amplitude are obtained respectively, and compared with the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude, real-time motor voltage fluctuation amplitude and real-time motor operating noise fluctuation amplitude respectively. If any of the fluctuation amplitudes are inconsistent, it is considered that the traction motor has a fault.

[0078] In some embodiments, based on different motor stator currents, different and / or the same harmonic currents are injected into the traction power supply system of the traction motor, and the fluctuation amplitudes of the motor stator currents caused by the changes are measured respectively, which are recorded as the motor stator current fluctuation amplitudes;

[0079] The motor stator current is used as a row vector, the harmonic current is used as a column vector, a matrix is ​​constructed, and then the motor stator current fluctuation amplitude is imported, and a surface fitting operation is performed to obtain a seventh fitting surface;

[0080] During fault diagnosis, harmonic current is injected into the traction power supply system of the traction motor to obtain real-time motor current, real-time motor speed, real-time motor voltage and real-time motor stator current, and the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude, real-time motor voltage fluctuation amplitude and real-time motor stator current fluctuation amplitude are measured. Based on the injected harmonic current, real-time motor current, real-time motor speed, real-time motor voltage, real-time motor stator current, the first fitting surface, the second fitting surface, the third fitting surface and the seventh fitting surface, the corresponding motor current fluctuation amplitude, motor speed fluctuation amplitude, motor voltage fluctuation amplitude and motor stator current fluctuation amplitude are obtained respectively, and compared with the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude, real-time motor voltage fluctuation amplitude and real-time motor stator current fluctuation amplitude respectively. If any of the fluctuation amplitudes are inconsistent, it is considered that the traction motor has a fault.

[0081] In summary, there are three situations in which different and / or the same harmonic currents are injected, taking motor current as an example.

[0082] The first case: different harmonic currents are injected and combined with different motor currents respectively, and the fluctuation amplitude of the motor current under different combinations is measured.

[0083] The second case: inject the same harmonic current and combine it with different motor currents, and measure the fluctuation amplitude of the motor current under different combinations.

[0084] The third case is a combination of the first and second cases (in no particular order of execution), that is, different harmonic currents are first injected, combined with different motor currents, and the fluctuation amplitudes of the motor currents under different combinations are measured; then the same harmonic current is injected, combined with different motor currents, and the fluctuation amplitudes of the motor currents under different combinations are measured.

[0085] For the descriptions of other parameters, refer to the above.

[0086] The motor current, motor speed, motor voltage, motor vibration frequency, motor temperature, motor operating noise and motor stator current, as well as the schemes of the first fitting surface to the seventh fitting surface can be used in combination to form a comprehensive implementation example, that is, to compare the seven fluctuation amplitudes. If any fluctuation amplitude is inconsistent, it is considered that the traction motor is faulty.

[0087] In some embodiments, when diagnosing a fault, different harmonic currents are successively injected into the traction power supply system of the traction motor to obtain the corresponding real-time motor current, real-time motor speed and real-time motor voltage, and the corresponding real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude and real-time motor voltage fluctuation amplitude are measured. Based on the injected different harmonic currents, the corresponding real-time motor current, real-time motor speed and real-time motor voltage, as well as the first fitting surface, the second fitting surface and the third fitting surface, the corresponding motor current fluctuation amplitude, motor speed fluctuation amplitude and motor voltage fluctuation amplitude are respectively obtained, and compared with the corresponding real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude and real-time motor voltage fluctuation amplitude, respectively. If any of the fluctuation amplitudes are inconsistent, it is considered that the traction motor has a fault.

[0088] Based on this embodiment, in the embodiments of motor vibration frequency, motor temperature, motor operating noise and motor stator current, as well as the fourth fitting surface to the seventh fitting surface, this embodiment can also be used in combination, that is, in the corresponding embodiments of the fourth fitting surface to the seventh fitting surface, during fault diagnosis, different harmonic currents are successively injected into the traction power supply system of the traction motor, and then the corresponding fluctuation amplitudes are compared respectively. If any fluctuation amplitude is inconsistent, it is considered that the traction motor has a fault.

[0089] In some embodiments, different harmonic currents are injected into the traction power supply system of the traction motor, and the motor current is gradually increased or decreased, the harmonic voltage generated thereby is measured, and the harmonic impedance is calculated;

[0090] Based on the injected harmonic current, motor current and harmonic impedance, a surface fitting method is used to obtain the first harmonic impedance fitting surface;

[0091] When diagnosing a fault, a harmonic current is injected into the traction power supply system of the traction motor, the harmonic voltage generated thereby is measured, and the real-time harmonic impedance is calculated; and a harmonic impedance reference value is obtained based on the real-time injected harmonic current, the real-time motor current and the first harmonic impedance fitting surface;

[0092] The real-time harmonic impedance is compared with the harmonic impedance reference value. If they are inconsistent, and the motor current fluctuation amplitude obtained by the first fitting surface is inconsistent with the real-time motor current fluctuation amplitude, it is considered that the traction motor is faulty.

[0093] If the real-time harmonic impedance is consistent with the harmonic impedance reference value, and the motor current fluctuation amplitude obtained by the first fitting surface is consistent with the real-time motor current fluctuation amplitude, it is considered that the traction motor has no fault;

[0094] If either of the two conditions is inconsistent, it is considered that the traction motor may be faulty.

[0095] In some embodiments, different harmonic currents are injected into the traction power supply system of the traction motor, and the motor speed is gradually increased or decreased, the harmonic voltage generated thereby is measured, and the harmonic impedance is calculated;

[0096] Based on the injected harmonic current, motor speed and harmonic impedance, the surface fitting method is used to obtain the second harmonic impedance fitting surface;

[0097] When diagnosing a fault, a harmonic current is injected into the traction power supply system of the traction motor, the harmonic voltage generated thereby is measured, and the real-time harmonic impedance is calculated; and based on the real-time injected harmonic current, the real-time motor speed and the second harmonic impedance fitting surface, a harmonic impedance reference value is obtained;

[0098] The real-time harmonic impedance is compared with the harmonic impedance reference value. If they are inconsistent, and the motor speed fluctuation amplitude obtained by the second fitting surface is inconsistent with the real-time motor speed fluctuation amplitude, it is considered that the traction motor is faulty.

[0099] If the real-time harmonic impedance is consistent with the harmonic impedance reference value, and the motor speed fluctuation amplitude obtained by the second fitting surface is consistent with the real-time motor speed fluctuation amplitude, it is considered that the traction motor has no fault;

[0100] If either of the two conditions is inconsistent, it is considered that the traction motor may be faulty.

[0101] In some embodiments, different harmonic currents are injected into the traction power supply system of the traction motor, and the motor voltage is gradually increased or decreased, the harmonic voltage generated thereby is measured, and the harmonic impedance is calculated;

[0102] Based on the injected harmonic current, motor voltage and harmonic impedance, the third harmonic impedance fitting surface is obtained using the surface fitting method;

[0103] When diagnosing a fault, a harmonic current is injected into the traction power supply system of the traction motor, the harmonic voltage generated thereby is measured, and the real-time harmonic impedance is calculated; and a harmonic impedance reference value is obtained based on the real-time injected harmonic current, the real-time motor voltage and the third harmonic impedance fitting surface;

[0104] The real-time harmonic impedance is compared with the harmonic impedance reference value. If they are inconsistent, and the motor voltage fluctuation amplitude obtained by the third fitting surface is inconsistent with the real-time motor voltage fluctuation amplitude, it is considered that the traction motor is faulty; (the case of both being inconsistent)

[0105] If the real-time harmonic impedance is consistent with the harmonic impedance reference value, and the motor voltage fluctuation amplitude obtained by the third fitting surface is consistent with the real-time motor voltage fluctuation amplitude, it is considered that the traction motor has no fault; (the case of both being consistent)

[0106] If any of the two conditions are inconsistent, it is considered that the traction motor may be faulty. (Any inconsistent condition)

[0107] Based on the above-mentioned motor current, motor speed and motor voltage, the corresponding embodiments of harmonic impedance (i.e., the above-mentioned three embodiments), in the embodiments of motor vibration frequency, motor temperature, motor operating noise and motor stator current, and the fourth fitting surface to the seventh fitting surface, this embodiment can also be used in combination, that is, in the corresponding embodiments of the fourth fitting surface to the seventh fitting surface, harmonic impedance calculation is performed, and surface fitting is performed to obtain the corresponding harmonic impedance fitting surface. When diagnosing a fault, the corresponding harmonic impedance comparison is performed. If they are all inconsistent, it is considered that the traction motor is faulty. If they are all consistent, it is considered that the traction motor is not faulty. If any one is inconsistent, it is considered that the traction motor may be faulty.

[0108] That is, based on the harmonic impedance fitting surface, the motor current, motor speed, motor voltage, motor vibration frequency, motor temperature, motor operating noise and motor stator current can each have an embodiment, with a total of seven embodiments; and the first to third fitting surfaces are taken as an embodiment, and the fourth to seventh fitting surfaces are each an embodiment, with a total of five embodiments, and these seven embodiments and five embodiments can be used in combination or together, and similarly, they can also be used in combination or together with the embodiment of "injecting different harmonic currents into the traction power supply system of the traction motor in sequence during fault diagnosis". In summary, all the embodiments of this specification can be used freely in combination, and the combined schemes are all the contents of this specification.

[0109] When used in combination, the diagnosis results may include "traction motor failure", "traction motor no failure" and "traction motor may have failure" at the same time. In this case, the diagnosis results can be merged according to conventional logic. If the diagnosis result includes "traction motor failure", then regardless of other results, the final diagnosis result of the combined use embodiment is traction motor failure; if the diagnosis results include "traction motor may have failure" and "traction motor no failure", then the final diagnosis result of the combined use embodiment is that the traction motor may have failure.

[0110] In this specification, errors are relatively allowed. Taking the motor current as an example, the motor current fluctuation amplitude obtained by the first fitting surface is 1mA, and the real-time motor current fluctuation amplitude is 1.1mA. The error is 0.1mA, and the two can be considered consistent. The specific error can be set according to actual needs.

[0111] This specification also discloses a traction motor fault diagnosis system, which is used to implement any one of the above-mentioned traction motor fault diagnosis methods, and the traction motor fault diagnosis system includes:

[0112] Data acquisition module, used to:

[0113] Based on different motor currents, different and / or the same harmonic currents are injected into the traction power supply system of the traction motor, and the fluctuation amplitudes of the motor currents caused thereby are measured respectively, which are recorded as the motor current fluctuation amplitudes;

[0114] Based on different motor speeds, different and / or the same harmonic currents are injected into the traction power supply system of the traction motor, and the fluctuation amplitudes of the motor speeds caused by the changes are measured respectively, which are recorded as the motor speed fluctuation amplitudes;

[0115] Based on different motor voltages, different and / or the same harmonic currents are injected into the traction power supply system of the traction motor, and the fluctuation amplitude of the motor voltage caused thereby is measured, which is recorded as the motor voltage fluctuation amplitude;

[0116] Surface fitting module for:

[0117] The motor current is used as a row vector and the harmonic current is used as a column vector to form a matrix, and then the motor current fluctuation amplitude is introduced to perform a surface fitting operation to obtain a first fitting surface;

[0118] The motor speed is used as a row vector and the harmonic current is used as a column vector to form a matrix, and then the motor speed fluctuation amplitude is introduced to perform a surface fitting operation to obtain a second fitting surface;

[0119] The motor voltage is used as a row vector, the harmonic current is used as a column vector, a matrix is ​​constructed, and then the motor voltage fluctuation amplitude is imported, and a surface fitting operation is performed to obtain a third fitting surface;

[0120] The fault diagnosis module is used to inject harmonic current into the traction power supply system of the traction motor during fault diagnosis, obtain real-time motor current, real-time motor speed and real-time motor voltage, and measure the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude and real-time motor voltage fluctuation amplitude. Based on the injected harmonic current, real-time motor current, real-time motor speed, real-time motor voltage, the first fitting surface, the second fitting surface and the third fitting surface, the corresponding motor current fluctuation amplitude, motor speed fluctuation amplitude and motor voltage fluctuation amplitude are respectively obtained, and compared with the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude and real-time motor voltage fluctuation amplitude respectively. If any fluctuation amplitude is inconsistent, it is considered that the traction motor has a fault.

[0121] When implementing the methods of the above embodiments, it is only necessary to add corresponding functional modules.

[0122] It should be noted that the relevant adjustments of motor current, motor speed, motor voltage, motor vibration frequency, motor temperature and motor stator current are existing technologies, and the present invention does not improve them. The adjustment technology can refer to the existing technology.

[0123] It should be understood that the above-mentioned surface fitting operation can use existing software tools, such as the Curve Fitting tool in Matlab. The above-mentioned modules can be existing data detection (collection) / measurement devices / sensors or data reading modules of the traction system, which can directly obtain the corresponding data of the traction system.

[0124] It is clear that by obtaining the corresponding data in the traction system in advance through existing equipment, a large amount of test data can be obtained. These test data can be simulation test data in the laboratory or actual measurement or operation data of the traction system in practice.

[0125] The above-described embodiments are used to illustrate the present invention, not to limit the present invention, so changes in the exemplified values ​​or replacement of equivalent elements should still fall within the scope of the present invention.

[0126] From the above detailed description, it can be understood by those skilled in the art that the present invention can indeed achieve the aforementioned objectives and is in compliance with the provisions of the Patent Law.

[0127] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they are aware of the basic creative concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention. The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. It should be pointed out that any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0128] It should be noted that the above description of the relevant process is only for example and explanation, and does not limit the scope of application of this specification. For those skilled in the art, various modifications and changes can be made to the process under the guidance of this specification. However, these modifications and changes are still within the scope of this specification.

[0129] The basic concepts have been described above. Obviously, for those of ordinary skill in the art who have read this application, the above invention disclosure is only for example and does not constitute a limitation of this application. Although not explicitly stated here, those of ordinary skill in the art may make various modifications, improvements and amendments to this application. Such modifications, improvements and amendments are suggested in this application, so such modifications, improvements and amendments still belong to the spirit and scope of the exemplary embodiments of this application.

[0130] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0131] In addition, it will be appreciated by those skilled in the art that various aspects of the present application may be illustrated and described by a number of patentable categories or situations, including any new and useful combination of processes, machines, products or substances, or any new and useful improvements thereto. Therefore, various aspects of the present application may be implemented entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The above hardware or software may all be referred to as "units", "modules" or "systems". In addition, various aspects of the present application may take the form of a computer program product embodied in one or more computer-readable media, wherein computer-readable program code is contained therein.

[0132] The computer program code required for the operation of each part of the application can be written in any one or more programming languages, including object-oriented programming languages ​​such as Java, Scale, Smalltalk, Elffell, JADE, Emerald, C++, C#, VB.NET, Python, etc., such as C programming language, Visual Basic, Fortran2103, Perl, COBOL2102, PHP, ABAP, such as Python, Ruby and Groovy dynamic programming language or other programming languages. The program code can be run completely on the user's computer, or run on the user's computer as an independent software package, or partly run on the user's computer and partly run on the remote computer, or run completely on the remote computer or server. In the latter case, the remote computer can be connected to the user's computer by any network form, such as local area network (LAN) or wide area network (WAN), or be connected to an external computer (such as by the Internet), or in a cloud computing environment, or as a service, such as software as a service (SaaS).

[0133] In addition, unless explicitly stated in the claims, the order of the processing elements and sequences described in this application, the use of alphanumeric characters, or the use of other names are not intended to limit the order of the processes and methods of this application. Although the above disclosure discusses some invention embodiments that are currently considered useful through various examples, it should be understood that such details are only for illustrative purposes, and the attached claims are not limited to the disclosed embodiments. On the contrary, the claims are intended to cover all modifications and equivalent combinations that are consistent with the essence and scope of the embodiments of this application. For example, although the implementation of the various components described above can be embodied in a hardware device, it can also be implemented as a pure software solution, for example, installation on an existing server or mobile device.

[0134] Similarly, it should be noted that in order to simplify the description disclosed in this application and thus help understand one or more embodiments of the invention, in the above description of the embodiments of the application, multiple features are sometimes combined into one embodiment, figure or description thereof. However, this method of the application should not be interpreted as reflecting the intention that the claimed object requires more features than those explicitly stated in each claim. On the contrary, the subject of the invention should have fewer features than the above single embodiment.

Claims

1. A method for traction motor fault diagnosis, characterized in that: include: Based on different motor currents, different and / or the same harmonic currents are injected into the traction power supply system of the traction motor, and the fluctuation amplitudes of the motor currents caused thereby are measured respectively, which are recorded as the motor current fluctuation amplitudes; Based on different motor speeds, different and / or the same harmonic currents are injected into the traction power supply system of the traction motor, and the fluctuation amplitudes of the motor speeds caused by the changes are measured respectively, which are recorded as the motor speed fluctuation amplitudes; Based on different motor voltages, different and / or the same harmonic currents are injected into the traction power supply system of the traction motor, and the fluctuation amplitude of the motor voltage caused thereby is measured, which is recorded as the motor voltage fluctuation amplitude; The motor current is used as a row vector, the harmonic current is used as a column vector, a matrix is ​​constructed, and then the motor current fluctuation amplitude is imported, and a surface fitting operation is performed to obtain a first fitting surface; The motor speed is used as a row vector and the harmonic current is used as a column vector to form a matrix, and then the motor speed fluctuation amplitude is introduced to perform a surface fitting operation to obtain a second fitting surface; The motor voltage is used as a row vector, the harmonic current is used as a column vector, a matrix is ​​constructed, and then the motor voltage fluctuation amplitude is imported, and a surface fitting operation is performed to obtain a third fitting surface; During fault diagnosis, harmonic current is injected into the traction power supply system of the traction motor to obtain real-time motor current, real-time motor speed and real-time motor voltage, and the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude and real-time motor voltage fluctuation amplitude are measured. Based on the injected harmonic current, real-time motor current, real-time motor speed, real-time motor voltage, the first fitting surface, the second fitting surface and the third fitting surface, the corresponding motor current fluctuation amplitude, motor speed fluctuation amplitude and motor voltage fluctuation amplitude are obtained respectively, and compared with the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude and real-time motor voltage fluctuation amplitude respectively. If any of the fluctuation amplitudes are inconsistent, it is considered that the traction motor has a fault.

2. The fault diagnosis method of the traction motor according to claim 1, characterized in that: Based on different motor vibration frequencies, different and / or the same harmonic currents are injected into the traction power supply system of the traction motor, and the fluctuation amplitudes of the motor vibration frequencies caused thereby are measured respectively, which are recorded as the motor vibration frequency fluctuation amplitudes; The motor vibration frequency is used as a row vector, and the harmonic current is used as a column vector to form a matrix, and then the motor vibration frequency fluctuation amplitude is imported, and a surface fitting operation is performed to obtain a fourth fitting surface; During fault diagnosis, harmonic current is injected into the traction power supply system of the traction motor to obtain real-time motor current, real-time motor speed, real-time motor voltage and real-time motor vibration frequency, and the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude, real-time motor voltage fluctuation amplitude and real-time motor vibration frequency fluctuation amplitude are measured. Based on the injected harmonic current, real-time motor current, real-time motor speed, real-time motor voltage, real-time motor vibration frequency, the first fitting surface, the second fitting surface, the third fitting surface and the fourth fitting surface, the corresponding motor current fluctuation amplitude, motor speed fluctuation amplitude, motor voltage fluctuation amplitude and motor vibration frequency fluctuation amplitude are obtained respectively, and compared with the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude, real-time motor voltage fluctuation amplitude and real-time motor vibration frequency fluctuation amplitude respectively. If any of the fluctuation amplitudes are inconsistent, it is considered that the traction motor has a fault.

3. The fault diagnosis method of the traction motor according to claim 1, characterized in that: Based on different motor temperatures, different and / or the same harmonic currents are injected into the traction power supply system of the traction motor, and the fluctuation amplitudes of the motor temperature caused thereby are measured respectively, which are recorded as the motor temperature fluctuation amplitudes; The motor temperature is used as a row vector, the harmonic current is used as a column vector, a matrix is ​​constructed, and then the motor temperature fluctuation amplitude is imported, and a surface fitting operation is performed to obtain a fifth fitting surface; During fault diagnosis, harmonic current is injected into the traction power supply system of the traction motor to obtain real-time motor current, real-time motor speed, real-time motor voltage and real-time motor temperature, and the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude, real-time motor voltage fluctuation amplitude and real-time motor temperature fluctuation amplitude are measured. Based on the injected harmonic current, real-time motor current, real-time motor speed, real-time motor voltage, real-time motor temperature, the first fitting surface, the second fitting surface, the third fitting surface and the fifth fitting surface, the corresponding motor current fluctuation amplitude, motor speed fluctuation amplitude, motor voltage fluctuation amplitude and motor temperature fluctuation amplitude are obtained respectively, and compared with the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude, real-time motor voltage fluctuation amplitude and real-time motor temperature fluctuation amplitude respectively. If any of the fluctuation amplitudes are inconsistent, it is considered that the traction motor has a fault.

4. The fault diagnosis method of the traction motor according to claim 1, characterized in that: Based on different motor working noises, different and / or the same harmonic currents are injected into the traction power supply system of the traction motor, and the fluctuation amplitude of the motor working noise caused by the changes is measured respectively, which is recorded as the motor working noise fluctuation amplitude; The motor working noise is taken as a row vector, the harmonic current is taken as a column vector, a matrix is ​​constructed, and then the motor working noise fluctuation amplitude is imported, and a surface fitting operation is performed to obtain a sixth fitting surface; During fault diagnosis, harmonic current is injected into the traction power supply system of the traction motor to obtain real-time motor current, real-time motor speed, real-time motor voltage and real-time motor operating noise, and the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude, real-time motor voltage fluctuation amplitude and real-time motor operating noise fluctuation amplitude are measured. Based on the injected harmonic current, real-time motor current, real-time motor speed, real-time motor voltage, real-time motor operating noise, the first fitting surface, the second fitting surface, the third fitting surface and the sixth fitting surface, the corresponding motor current fluctuation amplitude, motor speed fluctuation amplitude, motor voltage fluctuation amplitude and motor operating noise fluctuation amplitude are obtained respectively, and compared with the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude, real-time motor voltage fluctuation amplitude and real-time motor operating noise fluctuation amplitude respectively. If any of the fluctuation amplitudes are inconsistent, it is considered that the traction motor has a fault.

5. The fault diagnosis method of the traction motor according to claim 1, characterized in that: Based on different motor stator currents, different and / or the same harmonic currents are injected into the traction power supply system of the traction motor, and the fluctuation amplitudes of the motor stator currents caused by the changes are measured respectively, which are recorded as the motor stator current fluctuation amplitudes; The motor stator current is taken as a row vector, the harmonic current is taken as a column vector, a matrix is ​​constructed, and then the motor stator current fluctuation amplitude is imported, and a surface fitting operation is performed to obtain a seventh fitting surface; During fault diagnosis, harmonic current is injected into the traction power supply system of the traction motor to obtain real-time motor current, real-time motor speed, real-time motor voltage and real-time motor stator current, and the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude, real-time motor voltage fluctuation amplitude and real-time motor stator current fluctuation amplitude are measured. Based on the injected harmonic current, real-time motor current, real-time motor speed, real-time motor voltage, real-time motor stator current, the first fitting surface, the second fitting surface, the third fitting surface and the seventh fitting surface, the corresponding motor current fluctuation amplitude, motor speed fluctuation amplitude, motor voltage fluctuation amplitude and motor stator current fluctuation amplitude are obtained respectively, and compared with the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude, real-time motor voltage fluctuation amplitude and real-time motor stator current fluctuation amplitude respectively. If any of the fluctuation amplitudes are inconsistent, it is considered that the traction motor has a fault.

6. The fault diagnosis method of the traction motor according to claim 1, characterized in that: During fault diagnosis, different harmonic currents are injected into the traction power supply system of the traction motor in sequence to obtain the corresponding real-time motor current, real-time motor speed and real-time motor voltage, and measure the corresponding real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude and real-time motor voltage fluctuation amplitude. Based on the injected different harmonic currents, the corresponding real-time motor current, real-time motor speed and real-time motor voltage, as well as the first fitting surface, the second fitting surface and the third fitting surface, the corresponding motor current fluctuation amplitude, motor speed fluctuation amplitude and motor voltage fluctuation amplitude are obtained respectively, and compared with the corresponding real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude and real-time motor voltage fluctuation amplitude respectively. If any of the fluctuation amplitudes are inconsistent, it is considered that the traction motor has a fault.

7. The fault diagnosis method of the traction motor according to claim 1, characterized in that: Inject different harmonic currents into the traction power supply system of the traction motor, and gradually increase or decrease the motor current, measure the resulting harmonic voltage, and calculate the harmonic impedance; Based on the injected harmonic current, motor current and harmonic impedance, a surface fitting method is used to obtain the first harmonic impedance fitting surface; When diagnosing a fault, harmonic current is injected into the traction power supply system of the traction motor, the resulting harmonic voltage is measured, and the real-time harmonic impedance is calculated; and obtaining a harmonic impedance reference value based on the real-time injected harmonic current, the real-time motor current and the first harmonic impedance fitting surface; The real-time harmonic impedance is compared with the harmonic impedance reference value. If they are inconsistent, and the motor current fluctuation amplitude obtained by the first fitting surface is inconsistent with the real-time motor current fluctuation amplitude, it is considered that the traction motor is faulty. If the real-time harmonic impedance is consistent with the harmonic impedance reference value, and the motor current fluctuation amplitude obtained by the first fitting surface is consistent with the real-time motor current fluctuation amplitude, it is considered that the traction motor has no fault; If either of the two conditions is inconsistent, it is considered that the traction motor may be faulty.

8. The fault diagnosis method of the traction motor according to claim 1, characterized in that: Inject different harmonic currents into the traction power supply system of the traction motor, and gradually increase or decrease the motor speed, measure the resulting harmonic voltage, and calculate the harmonic impedance; Based on the injected harmonic current, motor speed and harmonic impedance, the surface fitting method is used to obtain the second harmonic impedance fitting surface; When diagnosing a fault, harmonic current is injected into the traction power supply system of the traction motor, the resulting harmonic voltage is measured, and the real-time harmonic impedance is calculated; And based on the real-time injected harmonic current, the real-time motor speed and the second harmonic impedance fitting surface, a harmonic impedance reference value is obtained; The real-time harmonic impedance is compared with the harmonic impedance reference value. If they are inconsistent, and the motor speed fluctuation amplitude obtained by the second fitting surface is inconsistent with the real-time motor speed fluctuation amplitude, it is considered that the traction motor is faulty. If the real-time harmonic impedance is consistent with the harmonic impedance reference value, and the motor speed fluctuation amplitude obtained by the second fitting surface is consistent with the real-time motor speed fluctuation amplitude, it is considered that the traction motor has no fault; If either of the two conditions is inconsistent, it is considered that the traction motor may be faulty.

9. The fault diagnosis method of the traction motor according to claim 1, characterized in that: Inject different harmonic currents into the traction power supply system of the traction motor, and gradually increase or decrease the motor voltage, measure the resulting harmonic voltage, and calculate the harmonic impedance; Based on the injected harmonic current, motor voltage and harmonic impedance, the third harmonic impedance fitting surface is obtained using the surface fitting method; When diagnosing a fault, harmonic current is injected into the traction power supply system of the traction motor, the resulting harmonic voltage is measured, and the real-time harmonic impedance is calculated; And based on the real-time injected harmonic current, the real-time motor voltage and the third harmonic impedance fitting surface, the harmonic impedance reference value is obtained; The real-time harmonic impedance is compared with the harmonic impedance reference value. If they are inconsistent, and the motor voltage fluctuation amplitude obtained by the third fitting surface is inconsistent with the real-time motor voltage fluctuation amplitude, it is considered that the traction motor is faulty. If the real-time harmonic impedance is consistent with the harmonic impedance reference value, and the motor voltage fluctuation amplitude obtained by the third fitting surface is consistent with the real-time motor voltage fluctuation amplitude, it is considered that the traction motor has no fault; If either of the two conditions is inconsistent, it is considered that the traction motor may be faulty.

10. A traction motor fault diagnosis system, characterized in that: A method for diagnosing a fault of a traction motor according to any one of claims 1 to 9, wherein the traction motor diagnosing system comprises: a data acquisition module, which is used to: Based on different motor currents, different and / or the same harmonic currents are injected into the traction power supply system of the traction motor, and the fluctuation amplitudes of the motor currents caused thereby are measured respectively, which are recorded as the motor current fluctuation amplitudes; Based on different motor speeds, different and / or the same harmonic currents are injected into the traction power supply system of the traction motor, and the fluctuation amplitudes of the motor speed changes caused thereby are measured respectively, which are recorded as the motor speed fluctuation amplitudes; Based on different motor voltages, different and / or the same harmonic currents are injected into the traction power supply system of the traction motor, and the fluctuation amplitude of the motor voltage caused thereby is measured, which is recorded as the motor voltage fluctuation amplitude; Surface fitting module for: The motor current is used as a row vector, the harmonic current is used as a column vector, a matrix is ​​constructed, and then the motor current fluctuation amplitude is imported, and a surface fitting operation is performed to obtain a first fitting surface; The motor speed is used as a row vector and the harmonic current is used as a column vector to form a matrix, and then the motor speed fluctuation amplitude is introduced to perform a surface fitting operation to obtain a second fitting surface; The motor voltage is used as a row vector, the harmonic current is used as a column vector, a matrix is ​​constructed, and then the motor voltage fluctuation amplitude is imported, and a surface fitting operation is performed to obtain a third fitting surface; The fault diagnosis module is used to inject harmonic current into the traction power supply system of the traction motor during fault diagnosis, obtain real-time motor current, real-time motor speed and real-time motor voltage, and measure the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude and real-time motor voltage fluctuation amplitude. Based on the injected harmonic current, real-time motor current, real-time motor speed, real-time motor voltage, the first fitting surface, the second fitting surface and the third fitting surface, the corresponding motor current fluctuation amplitude, motor speed fluctuation amplitude and motor voltage fluctuation amplitude are respectively obtained, and compared with the real-time motor current fluctuation amplitude, real-time motor speed fluctuation amplitude and real-time motor voltage fluctuation amplitude respectively. If any fluctuation amplitude is inconsistent, it is considered that the traction motor has a fault.

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