Train traction motor leakage current detection method and bearing damage assessment system

Abstract

The application provides a train traction motor leakage current detection method and bearing damage evaluation system. The method comprises the following steps: acquiring the running speed of the train and the input current of the traction motor under the current working condition; determining the frequency of the leakage current of the traction motor under the current working condition according to the running speed of the train; and determining the amplitude of the leakage current of the traction motor under the current working condition according to the input current of the traction motor. The leakage current is determined through the running speed of the train and the input current of the traction motor, so that the in-situ test of the train can be realized without disassembling the train, and the leakage current of the traction motor under each working condition can be accurately determined.

Description

Technical Field

[0001] The present application belongs to the field of leakage current detection technology, and in particular relates to a train traction motor leakage current detection method and a bearing damage assessment system. Background Art

[0002] Traction motors generate leakage current due to coupling, induction, and other factors, forming leakage current loops both internally and externally. When this leakage current flows through components like motor bearings, couplings, and gearboxes, it can cause electrical corrosion on the contacting tooth surfaces, accelerating component aging.

[0003] Because disassembling a running train is difficult, determining leakage current is difficult without installing a current sensor between the gear, coupling, and motor. Existing technology can detect leakage current through simulation, but the simulated leakage current often differs from the actual leakage current. Summary of the Invention

[0004] In view of this, the present invention provides a train traction motor leakage current detection method and a bearing damage assessment system, aiming to solve the problem of low leakage current detection accuracy in the existing technology.

[0005] A first aspect of an embodiment of the present invention provides a method for detecting leakage current of a train traction motor, comprising:

[0006] Obtain the train's running speed and the input current of the traction motor under the current working conditions;

[0007] Determine the frequency of the leakage current of the traction motor under the current working condition according to the running speed of the train;

[0008] The magnitude of the leakage current of the traction motor under the current working condition is determined according to the input current of the traction motor.

[0009] A second aspect of an embodiment of the present invention provides a method for detecting leakage current of a train traction motor, comprising:

[0010] A data acquisition module is used to obtain the running speed of the train and the input current of the traction motor under the current working conditions;

[0011] A first calculation module is used to determine the frequency of the leakage current of the traction motor under the current working condition according to the running speed of the train;

[0012] The second calculation module is used to determine the amplitude of the leakage current of the traction motor under the current working condition according to the input current of the traction motor.

[0013] The third aspect of an embodiment of the present invention provides a detection device, comprising a memory, a processor, and a computer program stored in the memory and runnable on the processor, characterized in that when the processor executes the computer program, the steps of the train traction motor leakage current detection method described in the first aspect above are implemented.

[0014] The fourth aspect of an embodiment of the present invention provides a computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, it implements the steps of the train traction motor leakage current detection method as described in the first aspect above.

[0015] A fifth aspect of an embodiment of the present invention provides a train traction motor bearing damage assessment system, characterized by comprising: a test bearing, a programmable current source, a vibration sensor, and a control device;

[0016] The control device is used to perform the following steps:

[0017] Obtain the leakage current of the train traction motor corresponding to various working conditions;

[0018] Controlling the test bearing to operate under each working condition and controlling the programmable current source to emit a simulated leakage current that is the same as the leakage current corresponding to each working condition;

[0019] The vibration sensor is used to detect the vibration displacement of the test bearing and report it to the control device;

[0020] The control device is further used to determine and evaluate damage to the test bearing based on the vibration displacement;

[0021] Among them, the leakage current of the train traction motor under each working condition is determined according to the train traction motor leakage current detection method described in the first aspect above.

[0022] The train traction motor leakage current detection method and bearing damage assessment system provided by embodiments of the present invention include obtaining the train's operating speed and the traction motor's input current under the current operating condition; determining the frequency of the traction motor's leakage current under the current operating condition based on the train's operating speed; and determining the amplitude of the traction motor's leakage current under the current operating condition based on the traction motor's input current. Determining the leakage current based on the train's operating speed and the traction motor's input current enables on-site vehicle testing without disassembling the vehicle, thereby accurately determining the traction motor's leakage current under various operating conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 This is a flow chart of a method for detecting leakage current of a train traction motor provided by an embodiment of the present invention;

[0025] Figure 2 2 is a schematic structural diagram of a train traction motor bearing damage assessment system provided by an embodiment of the present invention;

[0026] Figure 3 is a structural schematic diagram of a train traction motor bearing damage assessment system provided by another embodiment of the present invention;

[0027] Figure 4 1 is a schematic structural diagram of a train traction motor leakage current detection device provided by an embodiment of the present invention;

[0028] Figure 5 It is a structural diagram of the detection device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0029] In the following description, specific details such as particular system structures and techniques are provided for purposes of illustration, not limitation, to facilitate a thorough understanding of the embodiments of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

[0030] With the continuous advancement of power electronics technology, the switching performance of PWM inverters has continued to improve, significantly enhancing the dynamic and static control performance of PWM inverter-driven motors. However, as the switching frequency of PWM inverters increases, the common-mode voltage issues caused by the inverter output become increasingly serious. For example, common-mode voltage can induce high-amplitude shaft voltages on the motor shaft, generating bearing currents that can damage the motor bearings and shorten the motor's service life. Previous research on electrocorrosion in traction motor bearings and couplings has relied solely on simulation and theoretical analysis. This theoretical assessment of the electrocorrosion damage caused by leakage current to motor bearings is incomplete and can result in significant errors. Furthermore, damage tests for motor bearings primarily focus on mechanical damage, and testing for electrocorrosion damage to motor bearings is lacking. Accurately assessing electrocorrosion damage to motor bearings requires accurate measurement of the traction motor's leakage current.

[0031] Since the leakage current flowing through the bearing cannot be measured directly, an indirect measurement method is usually adopted in the prior art, that is, the bearing leakage current is indirectly measured by measuring the leakage current from the motor shaft to the gearbox (coupling leakage current).

[0032] However, the space between the coupling and the gearbox is extremely narrow, and the dimensions differ significantly from those used in conventional test benches. Furthermore, since these tests were conducted on an existing vehicle, the vehicle could not be disassembled. The existing vehicle lacked dedicated sensor installation equipment and locations, making the coupling leakage current sensor extremely difficult to install, making this method of measurement difficult to implement. Furthermore, due to the significant vibrations experienced by the train during operation, this measurement method was prone to the risk of measurement components falling, compromising safe operation.

[0033] The present invention provides a method for detecting leakage current of a train traction motor. The leakage current is determined by the running speed of the train and the input current of the traction motor. The method can realize on-site vehicle testing without disassembling the vehicle, thereby accurately determining the leakage current of the traction motor under various working conditions.

[0034] Figure 1 FIG. 1 is a flow chart of a method for detecting leakage current of a train traction motor provided by an embodiment of the present invention. Figure 1 As shown, in some embodiments, a method for detecting leakage current of a train traction motor includes:

[0035] S101, obtaining the running speed of the train and the input current of the traction motor under the current working condition.

[0036] In this embodiment, the running speed of the train and the input current of the traction motor can be obtained from the on-board control terminal of the train, or from the ground traffic dispatching center, which is not limited here. During each on-site vehicle test, the running speed and the input current of the traction motor are obtained in real time, and the working conditions of this on-site vehicle test are recorded. After traversing all working conditions, the leakage current under each working condition can be determined. The working condition of the train can be divided according to acceleration, such as acceleration, deceleration, and uniform speed, or according to speed level, such as 200km / h, 250km / h, and 300km / h. It can also be divided according to both acceleration and speed level, which is not limited here.

[0037] S102: Determine the frequency of the leakage current of the traction motor under the current working condition according to the running speed of the train.

[0038] Since the leakage current is caused by the common-mode voltage output by the inverter, and the frequency of the inverter is proportional to the speed of the motor, and the train speed is proportional to the speed of the motor, in this embodiment, the leakage current frequency of the traction motor can be calculated by detecting the running speed of the train.

[0039] S103 , determining the magnitude of the leakage current of the traction motor under the current working condition according to the input current of the traction motor.

[0040] The essence of leakage current is the induced current formed by the three-phase current loaded on the motor in the gear-coupling-motor circuit. Therefore, the load of the leakage current is inevitably affected by the input current of the traction motor. Therefore, in this embodiment, by detecting the input current of the traction motor, the amplitude of the leakage current of the traction motor can be calculated.

[0041] In this embodiment, the leakage current is determined by the running speed of the train and the input current of the traction motor, and the actual vehicle test can be carried out without disassembling the vehicle, thereby accurately determining the leakage current of the traction motor under various working conditions.

[0042] In some embodiments, S102 may include:

[0043] The frequency of the leakage current of the traction motor under the current working condition is determined according to the mechanical parameters of the traction motor, the operating speed, and the wheel parameters of the train.

[0044] In this embodiment, the rotation speed of the train traction motor can be determined according to the running speed and the wheel parameters of the train, and the frequency of the leakage current can be determined according to the rotation speed and mechanical parameters of the train traction motor.

[0045] In some embodiments, the mechanical parameters of the wheel include the number of traction motor pole pairs, the number of teeth on the gearbox gear, and the number of teeth on the gearbox gear. The wheel parameter of the train is the wheel diameter. The frequency of the leakage current of the traction motor under the current operating condition is determined according to the following formula:

[0046]

[0047] Among them, f is the frequency of leakage current, v is the operating speed, p is the number of pole pairs of the traction motor, n1 is the number of teeth on the large gear of the gearbox, n2 is the number of teeth on the small gear of the gearbox, and d is the wheel diameter.

[0048] In some embodiments, S103 may include:

[0049] Determine the three-phase common mode current based on the input current;

[0050] The amplitude of the leakage current of the traction motor under the current working condition is determined according to the three-phase common mode current and the electrical parameters of the traction motor.

[0051] In some embodiments, the electrical parameters of the traction motor include: coupling capacitance between the traction motor stator winding and the housing, coupling capacitance between the traction motor stator winding and the rotor, coupling capacitance between the traction motor rotor and the housing, and equivalent capacitance of the traction motor bearings. The input current of the traction motor includes phase A current, phase B current, and phase C current. The magnitude of the traction motor leakage current under the current operating condition is determined according to the following formula:

[0052]

[0053] Among them, I b is the magnitude of the leakage current, C wf is the coupling capacitance between the stator winding and the casing of the traction motor, C wr is the coupling capacitance between the stator winding and the rotor of the traction motor, C rf is the coupling capacitance between the traction motor rotor and the casing, C b is the equivalent capacitance of the traction motor bearing, I is the three-phase common mode current;

[0054] Among them, I=I A +I B +I C , I A is the phase A current, I B is the B phase current, I C is the C phase current.

[0055] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0056] Figure 2 FIG is a schematic diagram of the structure of the train traction motor bearing damage assessment system provided by an embodiment of the present invention. Figure 2 As shown, in some embodiments, a train traction motor bearing damage assessment system includes: a test bearing 21, a programmable current source 22, a vibration sensor 23, and a control device 24;

[0057] The control device 24 is used to perform the following steps:

[0058] Obtain the leakage current of the train traction motor corresponding to various working conditions;

[0059] Controlling the test bearing 21 to operate under each working condition and controlling the programmable current source 22 to emit a simulated leakage current that is the same as the leakage current corresponding to each working condition;

[0060] The vibration sensor 23 is used to detect the vibration displacement of the test bearing 21 and report it to the control device 24;

[0061] The control device 24 is further configured to determine damage to the test bearing 21 based on the vibration displacement;

[0062] The leakage current of the train traction motor under each working condition is determined according to the train traction motor leakage current detection method shown in any of the above embodiments.

[0063] The following describes the operation steps of each component in the train traction motor bearing damage assessment system through an implementation example, but it is not intended to be limiting.

[0064] Step 1: Determine the division rule of the experimental working conditions. The division rule of the experimental working conditions is input into the control device 24 by the experimenter.

[0065] During the operation of a high-speed EMU, it will successively go through three sections: acceleration, constant speed, and deceleration. If these three sections are grouped as one cycle, then the entire high-speed EMU operation process is composed of multiple such cycles. Therefore, in this implementation example, the cycles of three speed levels can be taken as test conditions, and the corresponding leakage current conditions and motor bearing speeds are the test conditions. The motor bearing load adopts no-load operation. The test conditions are shown in the following table:

[0066] Table 1 Test conditions

[0067] Working conditions Acceleration (km / h) Constant speed (km / h) Deceleration (km / h) <![CDATA[Corresponding rotational speed r·min -1 > 1 0～300 300 300～0 0～1730 2 0～250 250 250～0 0～1442 3 0～200 200 200～0 0～1153

[0068] Step 2: In response to the instruction input by the experimenter, the control device 24 selects an experimental condition and obtains the leakage current corresponding to the experimental condition.

[0069] In this embodiment, the detection equipment can measure the leakage current under various working conditions through the train traction motor leakage current detection method shown in any of the above embodiments, and upload it to the corresponding network platform or server. When performing damage assessment, the control device 24 can obtain the leakage current corresponding to the experimental working condition from the network platform or server, or directly obtain the leakage current corresponding to the experimental working condition from the detection equipment, which is not limited here.

[0070] Step 3: Determine the type of the test bearing 21 according to the type of motor bearing used in the EMU during the current vehicle test, and determine the number of the test bearings 21 according to the number of leakage current working conditions.

[0071] High-speed EMU motor bearings are mostly double-row tapered roller bearings and double-row cylindrical roller bearings. In this example, double-row tapered roller bearings were used as the test objects. To avoid accidental errors and facilitate comparison, four motor bearings were used for each test condition: three for the electro-corrosion test and one for the no-leakage current loading comparison test.

[0072] Step 4: Determine the test performance index and corresponding evaluation method based on the motor bearing failure performance index.

[0073] Once the motor bearings are damaged by electro-corrosion, the raceways and rolling elements will suffer surface damage and lubricant aging, which will in turn lead to increased vibration of the motor bearings. Therefore, in this step, the vibration displacement of the motor bearings and the failure time are used as performance indicators, and the failure time is the time when the vibration displacement of the motor bearings reaches the limit value. Under the same limit value, the failure time of three motor bearings in each group under three groups of working conditions is tested. If there are abnormal points, the test is repeated. If there are no abnormal points, the average value of the failure time of the three motor bearings is taken as the failure time under this working condition. According to the failure time and vibration displacement, the impact of the electro-corrosion damage caused by the leakage current on the motor bearings and the impact of leakage currents of different amplitude frequencies on the electro-corrosion damage of the motor bearings are evaluated.

[0074] In step 5, the control device 24 sends corresponding control parameters to the programmable current source 22 according to the leakage current corresponding to the experimental working condition, so that the programmable current source 22 loads the experimental bearing 21 with a simulated leakage current that is the same as the leakage current corresponding to the experimental working condition.

[0075] The leakage current requires many simulated working conditions, and the current is not constant during the loading process, but changes over time. Therefore, conventional current sources cannot meet the test requirements. Therefore, the present invention uses a programmable current source 22 and a control device 24 to form a leakage current loading device. In this embodiment, the vibration sensor 23 can be a vibration acceleration sensor that forms a feedback link, collects vibration displacement, and feeds it back to the control device 24. When the vibration displacement is greater than the limit value, the central control device issues a stop command, and the programmable current source stops loading the leakage current.

[0076] Step 5: Select performance indicator sensors, host computer, and write the software system.

[0077] During the electrolytic corrosion damage test for motor bearings, the test bearing 21 operates at high speed, making it unsuitable to directly mount the sensor on the motor bearing. The performance indicator, vibration displacement, cannot be directly measured. The present invention employs an indirect measurement method, using a vibration acceleration sensor to measure the motor bearing's vibration acceleration and then performing a double integration to obtain the motor bearing's vibration displacement. The vibration sensor is mounted on the left platform of the test bearing 21.

[0078] In this embodiment, the performance indicator sensor used to evaluate damage and the vibration sensor used in the feedback link may be the same device.

[0079] Step 6: Install the test bearing 21 on the motor bearing leakage current test research platform, and install the performance index sensor on the test platform.

[0080] In this step, the test bearing 21 can be installed on the test research platform using the existing threaded holes, while ensuring good contact between the motor bearing and the platform to prevent grease, dust, etc. from affecting the conductive performance. The vibration sensor is bonded to the platform on the left side of the test bearing 21.

[0081] Step 7: Load the set working conditions, track and monitor the changes in the performance indicators of the test bearing 21, and record them.

[0082] In this step, the test can be carried out in sequence according to the operating conditions of 200km / h, 250km / h, and 300km / h. The software system tracks, detects, and displays the vibration displacement of the test bearing 21, and records the failure time when the vibration displacement of the test bearing 21 reaches the limit value.

[0083] Step 8: Evaluate the damage caused by leakage current to the motor bearing according to the evaluation method.

[0084] In this step, the vibration displacements of the test bearing 21 and the comparison bearing under the same operating conditions can be compared at the time of failure. The test bearing 21 and the comparison bearing can be disassembled to observe the number of grooves on the inner and outer rings of the motor bearing and measure the depth of the grooves. The impact of electrocorrosion damage caused by the leakage current on the motor bearing can be assessed based on the magnitude of the vibration displacement, the number of grooves, and the depth of the grooves. Three groups of test bearings 21 under leakage current conditions can be compared at their time to failure to assess the impact of leakage currents of different amplitudes and frequencies on electrocorrosion damage to the motor bearing.

[0085] Figure 3 FIG. 1 is a structural diagram of a train traction motor bearing damage assessment system provided by another embodiment of the present invention. Figure 3 As shown, in some embodiments, the control device 24 includes a central control device 31 and a host computer 32;

[0086] The central control device 31 is used to obtain the leakage current of the train traction motor corresponding to each working condition and control the test bearing 21 to operate under the simulated working condition and control the programmable current source 22 to emit a simulated leakage current that is the same as the leakage current corresponding to each working condition;

[0087] The vibration sensor 23 is used to detect the vibration displacement of the test bearing 21 and report it to the central control device 31 and the host computer 32;

[0088] The host computer 32 is used to determine and evaluate the damage of the test bearing 21 based on the vibration displacement;

[0089] The central control device 31 is further used to correct the analog leakage current emitted by the programmable current source 22 according to the vibration displacement.

[0090] In this embodiment, the central control device 31 can be a single-chip microcomputer, MCU, etc., and the host computer 32 can be a terminal device such as a desktop computer, laptop, mobile phone, etc., without limitation. The present invention uses the measurement and control system software LabVIEW development platform for software design to achieve data processing, data display and data recording.

[0091] In some embodiments, the system further includes a current sensor 33;

[0092] The current sensor 33 is used to detect the actual current loaded on the test bearing 21 and report it to the central control device 31;

[0093] The central control device 31 is further configured to correct the simulated leakage current emitted by the programmable current source 22 according to the actual current.

[0094] In this embodiment, the leakage current loading method is as follows: at the beginning of the test, an initial working condition is set and transmitted to the control device 24. The control device 24 generates control parameters and controls the programmable current source to generate leakage current under the corresponding working condition.

[0095] In this embodiment, an electromagnetic induction current sensor can be used to measure the leakage current and fixed to the test platform through the mounting threaded hole. When the leakage current is a periodic current, the programmable current source 22 loads the leakage current on the test bearing 21 in a cyclic loading manner. The current sensor 33 and the vibration acceleration sensor monitor the magnitude of the loaded leakage current and the vibration displacement in real time and feed back the information to the central control device 31. When the actual magnitude of the loaded leakage current fed back by the current sensor 33 differs significantly from the set magnitude of the leakage current, the central control device 31 adjusts the control parameters to reduce the deviation. Among them, the vibration displacement feedback priority is greater than the current feedback priority.

[0096] Figure 4 Schematic diagram of the structure of the train traction motor leakage current detection device provided by an embodiment of the present invention. In some embodiments, the train leakage current traction motor leakage current detection device 4 includes:

[0097] The data acquisition module 410 is used to obtain the running speed of the train and the input current of the traction motor under the current working conditions;

[0098] A first calculation module 420 is configured to determine the frequency of the leakage current of the traction motor under the current operating condition according to the running speed of the train;

[0099] The second calculation module 430 is used to determine the magnitude of the leakage current of the traction motor under the current working condition according to the input current of the traction motor.

[0100] Optionally, the frequency of the leakage current of the traction motor under the current working condition is determined according to the running speed of the train, including:

[0101] The frequency of the leakage current of the traction motor under the current working condition is determined according to the mechanical parameters of the traction motor, the operating speed, and the wheel parameters of the train.

[0102] Optionally, the mechanical parameters of the wheel include the number of pole pairs of the traction motor, the number of teeth of the large gear of the gearbox, and the number of teeth of the small gear of the gearbox; the wheel parameter of the train is the wheel diameter; the frequency of the leakage current of the traction motor under the current working condition is determined according to the following formula:

[0103]

[0104] Among them, f is the frequency of leakage current, v is the operating speed, p is the number of pole pairs of the traction motor, n1 is the number of teeth on the large gear of the gearbox, n2 is the number of teeth on the small gear of the gearbox, and d is the wheel diameter.

[0105] Optionally, determining the magnitude of the leakage current of the traction motor under the current working condition according to the input current of the traction motor includes:

[0106] Determine the three-phase common mode current based on the input current;

[0107] The amplitude of the leakage current of the traction motor under the current working condition is determined according to the three-phase common mode current and the electrical parameters of the traction motor.

[0108] Optionally, the electrical parameters of the traction motor include: coupling capacitance between the traction motor stator winding and the housing, coupling capacitance between the traction motor stator winding and the rotor, coupling capacitance between the traction motor rotor and the housing, and equivalent capacitance of the traction motor bearings; the input current of the traction motor includes A-phase current, B-phase current, and C-phase current; the amplitude of the leakage current of the traction motor under the current operating condition is determined according to the following formula:

[0109]

[0110] Among them, I b is the magnitude of the leakage current, C wf is the coupling capacitance between the stator winding and the casing of the traction motor, C wr is the coupling capacitance between the stator winding and the rotor of the traction motor, C rf is the coupling capacitance between the traction motor rotor and the casing, C b is the equivalent capacitance of the traction motor bearing, I is the three-phase common mode current;

[0111] Among them, I=I A +I B +I C ,,I A is the phase A current, I B is the B phase current, I C is the C phase current.

[0112] The train traction motor leakage current detection device provided in this embodiment can be used to execute the above method embodiment. Its implementation principle and technical effects are similar, and this embodiment will not be repeated here.

[0113] Figure 5 Schematic diagram of the detection device provided by the embodiment of the present invention. Figure 5 As shown, an embodiment of the present invention provides a detection device 5, which includes: a processor 50, a memory 51, and a computer program 52 stored in the memory 51 and executable on the processor 50. When the processor 50 executes the computer program 52, the steps in the above-mentioned embodiments of the train traction motor leakage current detection method are implemented, such as Figure 2 Alternatively, when the processor 50 executes the computer program 52, the functions of each module / unit in the above-mentioned system embodiments are realized, for example Figure 4 Functions of modules 410 to 430 are shown.

[0114] Exemplarily, the computer program 52 may be divided into one or more modules / units, one or more of which are stored in the memory 51 and executed by the processor 50 to implement the present invention. The one or more modules / units may be a series of computer program instruction segments capable of implementing specific functions, and the instruction segments are used to describe the execution process of the computer program 52 in the detection device 5.

[0115] The detection device 5 can be a single chip microcomputer, MCU, desktop computer, notebook, PDA and other computing devices. The terminal can include, but is not limited to, a processor 50 and a memory 51. Those skilled in the art will understand that Figure 5 It is only an example of the detection device 5 and does not constitute a limitation of the detection device 5. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the terminal may also include input and output devices, network access devices, buses, etc.

[0116] The processor 50 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0117] The memory 51 can be an internal storage unit of the detection device 5, such as a hard disk or a memory of the detection device 5. The memory 51 can also be an external storage device of the detection device 5, such as a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card) etc. equipped on the detection device 5. Further, the memory 51 can also include both the internal storage unit of the detection device 5 and the external storage device. The memory 51 is used to store other programs and data required for computer programs and terminals. The memory 51 can also be used to temporarily store data that has been output or is about to be output.

[0118] An embodiment of the present invention provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the steps in the above-mentioned train traction motor leakage current detection system embodiment are implemented.

[0119] A computer-readable storage medium stores a computer program 52, which includes program instructions. When executed by the processor 50, the program instructions implement all or part of the process steps in the above-described method embodiments. The computer program 52 can also be used to instruct related hardware to complete the process. The computer program 52 can be stored in a computer-readable storage medium. When executed by the processor 50, the computer program 52 can implement the steps of each of the above-described method embodiments. The computer program 52 includes computer program code, which can be in source code form, object code form, executable file, or some intermediate form. The computer-readable medium can include: any entity or device capable of carrying computer program code, recording medium, USB flash drive, mobile hard drive, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal, and software distribution medium. It should be noted that the content included in the computer-readable medium can be appropriately increased or decreased based on the requirements of legislation and patent practice in a jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media does not include electric carrier signals and telecommunication signals.

[0120] The computer-readable storage medium may be an internal storage unit of the terminal in any of the aforementioned embodiments, such as a hard disk or memory of the terminal. The computer-readable storage medium may also be an external storage device of the terminal, such as a plug-in hard disk equipped on the terminal, a smart memory card (SMC), a secure digital (SD) card, a flash memory card, etc. Furthermore, the computer-readable storage medium may include both an internal storage unit of the terminal and an external storage device. The computer-readable storage medium is used to store computer programs and other programs and data required by the terminal. The computer-readable storage medium may also be used to temporarily store data that has been output or is about to be output.

[0121] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0122] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0123] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0124] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present invention.

[0125] In the embodiments provided herein, it should be understood that the disclosed devices / terminals and methods can be implemented in other ways. For example, the device / terminal embodiments described above are merely illustrative. For example, the division of modules or units is merely a logical functional division. In actual implementation, other division methods may be used, such as multiple units or components being combined or integrated into another system, or some features being ignored or not implemented. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interface, or the indirect coupling or communication connection of devices or units may be electrical, mechanical, or other forms.

[0126] Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0127] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0128] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the process in the above-mentioned embodiment method, and can also be completed by a computer program to instruct the relevant hardware. The computer program can be stored in a computer-readable storage medium, and when the computer program is executed by the processor, it can implement the steps of each of the above-mentioned method embodiments. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media does not include electric carrier signals and telecommunication signals.

[0129] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the scope of protection of the present invention.

Claims

1. A method for detecting leakage current of a train traction motor, characterized in that: include: Obtain the train's running speed and the input current of the traction motor under the current working conditions; Determine the frequency of the leakage current of the traction motor under the current working condition according to the running speed of the train; Determining the magnitude of the leakage current of the traction motor under the current working condition according to the input current of the traction motor; According to the running speed of the train, determine the frequency of the leakage current of the traction motor under the current working condition, including: determining the frequency of the leakage current of the traction motor under the current working condition according to the mechanical parameters of the traction motor, the operating speed, and the wheel parameters of the train; The mechanical parameters of the wheel include the number of pole pairs of the traction motor, the number of teeth of the large gear of the gearbox, and the number of teeth of the small gear of the gearbox; the wheel parameter of the train is the wheel diameter; the frequency of the leakage current of the traction motor under the current working condition is determined according to the following formula: in, is the frequency of the leakage current, is the running speed, is the number of pole pairs of the traction motor, is the number of teeth of the large gear of the gearbox, is the number of teeth of the gearbox pinion, is the wheel diameter; Determine the magnitude of the leakage current of the traction motor under the current working condition based on the input current of the traction motor, including: determining a three-phase common-mode current according to the input current; determining the magnitude of the leakage current of the traction motor under the current working condition according to the three-phase common mode current and the electrical parameters of the traction motor; The electrical parameters of the traction motor include: coupling capacitance between the traction motor stator winding and the housing, coupling capacitance between the traction motor stator winding and the rotor, coupling capacitance between the traction motor rotor and the housing, and equivalent capacitance of the traction motor bearings; the input current of the traction motor includes A-phase current, B-phase current, and C-phase current; the amplitude of the leakage current of the traction motor under the current working condition is determined according to the following formula: in, is the magnitude of the leakage current, is the coupling capacitance between the stator winding and the casing of the traction motor, is the coupling capacitance between the stator winding and the rotor of the traction motor, is the coupling capacitance between the traction motor rotor and the casing, is the equivalent capacitance of the traction motor bearing, is the three-phase common mode current; in, , is the A-phase current, is the B-phase current, is the C-phase current.

2. A detection device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the train traction motor leakage current detection method as described in claim 1 are implemented.

3. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the train traction motor leakage current detection method as described in claim 1 are implemented.

4. A train traction motor bearing damage assessment system, characterized in that: include: Test bearings, programmable current sources, vibration sensors, and control devices; The control device is used to perform the following steps: Obtain the leakage current of the train traction motor corresponding to various working conditions; Controlling the test bearing to operate under each working condition and controlling the programmable current source to emit a simulated leakage current that is the same as the leakage current corresponding to each working condition; The vibration sensor is used to detect the vibration displacement of the test bearing and report it to the control device; The control device is further used to determine and evaluate damage to the test bearing based on the vibration displacement; Wherein, the leakage current of the train traction motor under each working condition is determined according to the train traction motor leakage current detection method as described in claim 1 above.

5. The train traction motor bearing damage assessment system according to claim 4, characterized in that: The control device includes a central control device and a host computer; The central control device is used to obtain the leakage current of the train traction motor corresponding to each working condition, control the test bearing to operate under the simulated working condition, and control the programmable current source to emit a simulated leakage current that is the same as the leakage current corresponding to each working condition; The vibration sensor is used to detect the vibration displacement of the test bearing and report it to the central control device and the host computer; The host computer is used to determine and evaluate the damage of the test bearing according to the vibration displacement; The central control device is further used to correct the analog leakage current emitted by the programmable current source according to the vibration displacement.

6. The train traction motor bearing damage assessment system according to claim 5, characterized in that: The system also includes a current sensor; The current sensor is used to detect the actual current loaded on the test bearing and report it to the central control device; The central control device is further configured to correct the simulated leakage current emitted by the programmable current source according to the actual current.

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