Power motor fault diagnosis method and device, computer device and storage medium

Abstract

The application relates to a power motor fault diagnosis method and device, computer equipment, a storage medium and a computer program product. The method comprises the following steps: controlling the cross-axis current of a power motor to be a first preset value, the direct-axis current to be a second preset value, and controlling the electric angle of the power motor to increase from a first angle to a second angle; during the process that the electric angle increases from the first angle to the second angle, acquiring the cross-axis voltage and the direct-axis voltage collected respectively at each electric angle; according to the cross-axis voltage and the direct-axis voltage corresponding to each electric angle, calculating the actual included angle between the voltage vector and the current vector; acquiring the theoretical included angle between the voltage vector and the current vector; comparing the actual included angle with the theoretical included angle, and determining the fault diagnosis result of the power motor according to the comparison result. The method can improve the accuracy of power motor fault diagnosis.

Description

Technical Field

[0001] This application relates to the field of power motor control technology, and in particular to a method, apparatus, computer equipment, and storage medium for diagnosing power motor faults. Background Technology

[0002] A drive motor is a device that uses an electronic controller to control the motor to achieve the required torque or speed, thus providing power to a vehicle. If the drive motor malfunctions during vehicle use, it may threaten the safety of personnel.

[0003] Traditional methods typically determine whether a motor is faulty based on the actual torque produced by the motor and the required torque. However, this method is not very accurate in diagnosing motor faults. Summary of the Invention

[0004] Therefore, it is necessary to provide a method, apparatus, computer equipment, computer-readable storage medium, and computer program product for diagnosing power motor faults that can improve the accuracy of power motor fault diagnosis, in response to the above-mentioned technical problems.

[0005] Firstly, this application provides a method for diagnosing faults in a power motor. The method includes:

[0006] The quadrature-axis current of the power motor is controlled to a first preset value, the direct-axis current is controlled to a second preset value, and the electrical angle of the power motor is controlled to increase from the first angle to the second angle.

[0007] During the process of the electrical angle increasing from the first angle to the second angle, the quadrature-axis voltage and direct-axis voltage collected at each electrical angle are obtained.

[0008] Based on the quadrature-axis voltage and direct-axis voltage corresponding to each electrical angle, the actual angle between the voltage vector and the current vector is calculated.

[0009] Obtain the theoretical angle between the voltage vector and the current vector;

[0010] The actual included angle is compared with the theoretical included angle, and the fault diagnosis result of the power motor is determined based on the comparison result.

[0011] In one embodiment, the method further includes:

[0012] Determine if the ignition switch is working;

[0013] Determine if the brake is in an active state;

[0014] Determine if the power inverter is active.

[0015] Determine if the current controller is active;

[0016] Determine if the rotor speed is within the preset speed range;

[0017] If the ignition switch is active, the brake is activated, the power inverter is activated, the current controller is activated, and the rotor speed is within the preset speed range, then the diagnostic enable condition is determined to be met.

[0018] If the diagnostic enable condition is met, then the step of controlling the quadrature axis current of the power motor to be a first preset value and the direct axis current to be a second preset value is executed.

[0019] In one embodiment, the step of calculating the actual angle between the voltage vector and the current vector based on the quadrature-axis voltage and direct-axis voltage corresponding to each electrical angle includes:

[0020] The quadrature-axis voltage and direct-axis voltage corresponding to each electrical angle are processed to obtain the first angle between the voltage vector and the positive direction of the direct axis;

[0021] Obtain the second angle between the current vector and the positive direction of the direct axis;

[0022] Based on the first included angle and the second included angle, the actual included angle between the voltage vector and the current vector is determined.

[0023] In one embodiment, obtaining the theoretical angle between the voltage vector and the current vector includes:

[0024] Obtain the direct-axis current vector rotation frequency, motor inductance, and motor stator impedance;

[0025] The theoretical angle between the voltage vector and the current vector is calculated based on the rotation frequency of the direct-axis current vector, the motor inductance, and the motor stator impedance.

[0026] In one embodiment, determining the fault diagnosis result of the power motor based on the comparison result includes:

[0027] If the difference between the actual included angle and the theoretical included angle is within the preset error range, then it is determined that the power motor has not malfunctioned.

[0028] If the difference between the actual included angle and the theoretical included angle is outside the preset error range, the maximum three-phase current is obtained, and the fault diagnosis result is determined based on the maximum three-phase current. The maximum three-phase current is obtained by monitoring the power motor during the process of controlling the electrical angle to increase from the first angle to the second angle.

[0029] In one embodiment, determining the fault diagnosis result based on the maximum three-phase current includes:

[0030] Compare the maximum three-phase current with the preset three-phase current threshold;

[0031] If the maximum three-phase current is less than the preset three-phase current threshold, then the power motor is determined to have an open circuit fault.

[0032] If the maximum three-phase current is greater than the preset three-phase current threshold, then a short-circuit fault is determined to have occurred in the power motor.

[0033] Secondly, this application also provides a power motor fault diagnosis device. The device includes:

[0034] The control module is used to control the quadrature-axis current of the power motor to a first preset value and the direct-axis current to a second preset value, and to control the electrical angle of the power motor to increase from the first angle to the second angle.

[0035] The first acquisition module is used to acquire the quadrature-axis voltage and direct-axis voltage collected at each electrical angle as the electrical angle increases from the first angle to the second angle.

[0036] The calculation module is used to calculate the actual angle between the voltage vector and the current vector based on the quadrature-axis voltage and direct-axis voltage corresponding to each electrical angle.

[0037] The second acquisition module is used to acquire the theoretical angle between the voltage vector and the current vector;

[0038] The diagnostic module is used to compare the actual included angle with the theoretical included angle, and determine the fault diagnosis result of the power motor based on the comparison result.

[0039] Thirdly, this application also provides a computer device. The computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to perform the following steps:

[0040] The quadrature-axis current of the power motor is controlled to a first preset value, the direct-axis current is controlled to a second preset value, and the electrical angle of the power motor is controlled to increase from the first angle to the second angle.

[0041] During the process of the electrical angle increasing from the first angle to the second angle, the quadrature-axis voltage and direct-axis voltage collected at each electrical angle are obtained.

[0042] Based on the quadrature-axis voltage and direct-axis voltage corresponding to each electrical angle, the actual angle between the voltage vector and the current vector is calculated.

[0043] Obtain the theoretical angle between the voltage vector and the current vector;

[0044] The actual included angle is compared with the theoretical included angle, and the fault diagnosis result of the power motor is determined based on the comparison result.

[0045] Fourthly, this application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program thereon, which, when executed by a processor, performs the following steps:

[0046] The quadrature-axis current of the power motor is controlled to a first preset value, the direct-axis current is controlled to a second preset value, and the electrical angle of the power motor is controlled to increase from the first angle to the second angle.

[0047] During the process of the electrical angle increasing from the first angle to the second angle, the quadrature-axis voltage and direct-axis voltage collected at each electrical angle are obtained.

[0048] Based on the quadrature-axis voltage and direct-axis voltage corresponding to each electrical angle, the actual angle between the voltage vector and the current vector is calculated.

[0049] Obtain the theoretical angle between the voltage vector and the current vector;

[0050] The actual included angle is compared with the theoretical included angle, and the fault diagnosis result of the power motor is determined based on the comparison result.

[0051] Fifthly, this application also provides a computer program product. The computer program product includes a computer program that, when executed by a processor, performs the following steps:

[0052] The quadrature-axis current of the power motor is controlled to a first preset value, the direct-axis current is controlled to a second preset value, and the electrical angle of the power motor is controlled to increase from the first angle to the second angle.

[0053] During the process of the electrical angle increasing from the first angle to the second angle, the quadrature-axis voltage and direct-axis voltage collected at each electrical angle are obtained.

[0054] Based on the quadrature-axis voltage and direct-axis voltage corresponding to each electrical angle, the actual angle between the voltage vector and the current vector is calculated.

[0055] Obtain the theoretical angle between the voltage vector and the current vector;

[0056] The actual included angle is compared with the theoretical included angle, and the fault diagnosis result of the power motor is determined based on the comparison result.

[0057] The aforementioned method, apparatus, computer equipment, storage medium, and computer program product for diagnosing motor faults control the quadrature-axis current of the motor to a first preset value and the direct-axis current to a second preset value. They also control the electrical angle of the motor to increase from a first angle to a second angle. During this increase, the quadrature-axis voltage and direct-axis voltage are acquired at each electrical angle. Based on these voltages, the actual angle between the voltage vector and the current vector is calculated, and the theoretical angle is obtained. Finally, the actual angle is compared with the theoretical angle, and the fault diagnosis result is determined based on the comparison result. By determining whether the actual angle between the voltage vector and the current vector is within a certain error range, motor faults can be diagnosed, thereby improving the accuracy of fault diagnosis. Attached Figure Description

[0058] Figure 1 This is a diagram illustrating the application environment of a power motor fault diagnosis method in one embodiment.

[0059] Figure 2 This is a flowchart illustrating a power motor fault diagnosis method in one embodiment;

[0060] Figure 3 This is a flowchart illustrating a power motor fault diagnosis method in another embodiment;

[0061] Figure 4 This is a structural block diagram of a power motor fault diagnosis device in one embodiment;

[0062] Figure 5 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0063] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0064] It should be noted that the terms "comprising," "including," "having," and any variations thereof, as used in this application, are intended to cover non-exclusive inclusion. For example, a process, method, product, or apparatus that includes a series of steps or means is not necessarily limited to the steps that are clearly listed, but may also include other steps or means not clearly listed or inherent to these processes, methods, products, or apparatuses. The term "and / or," as used in this application, includes any and all combinations of one or more of the associated listed items.

[0065] Furthermore, the terms "first," "second," etc., used in this application are for naming purposes to distinguish similar objects, but these objects themselves are not limited by these terms. It should be understood that these terms may be used interchangeably where appropriate without departing from the scope of this application. For example, "first angle" may be described as "second angle," and similarly, "second angle" may be described as "first angle."

[0066] The power motor fault diagnosis method provided in this application embodiment can be applied to, for example, Figure 1 The application environment is shown. In this environment, the vehicle controller 104 is installed on the target vehicle 102. The vehicle controller 104 can communicate with the computer device 106 via a network, and the computer device 106 can control the power motor of the target vehicle 102 through the vehicle controller 104. A data storage system can store the data that the computer device 106 needs to process. The data storage system can be integrated into the computer device 106, or it can be located in the cloud or on another network server. The computer device 106 controls the quadrature-axis current of the power motor to a first preset value and the direct-axis current to a second preset value via the vehicle controller 104, and controls the electrical angle of the power motor to increase from the first angle to the second angle. As the electrical angle increases from the first angle to the second angle, the vehicle controller 104 acquires the quadrature-axis voltage and direct-axis voltage collected at each electrical angle and sends them to the computer device 106. After receiving the quadrature-axis voltage and direct-axis voltage collected at each electrical angle from the vehicle controller 104, the computer device 106 calculates the actual angle between the voltage vector and the current vector based on the quadrature-axis voltage and direct-axis voltage corresponding to each electrical angle. Then, the computer device 106 acquires the theoretical angle between the voltage vector and the current vector, and finally compares the actual angle with the theoretical angle, and determines the fault diagnosis result of the power motor based on the comparison result. In this context, computer device 106 can be a terminal or a server. Terminals can be, but are not limited to, various personal computers, laptops, smartphones, tablets, IoT devices, and portable wearable devices. IoT devices can include smart speakers, smart TVs, smart air conditioners, and smart in-vehicle devices. Portable wearable devices can include smartwatches, smart bracelets, and head-mounted devices. The server is implemented using a standalone server or a server cluster consisting of multiple servers.

[0067] In one embodiment, such as Figure 2 As shown, a method for diagnosing faults in a power motor is provided, which is then applied to... Figure 1 Taking a computer device as an example, the explanation includes the following steps:

[0068] Step 202: Control the quadrature axis current of the power motor to a first preset value, the direct axis current to a second preset value, and control the electrical angle of the power motor to increase from the first angle to the second angle.

[0069] In this context, the quadrature axis (also called the q-axis) and direct axis (also called the d-axis) of the motor are coordinate axes established relative to the rotor. The electrical angle measures the spatial distance on the rotor surface and is also called the spatial angle. The direct axis is the axis along which the magnetic poles of the rotor magnets are located (the direction of the rotor magnetic field), and its direction is from the S pole to the N pole. The quadrature axis is perpendicular to the direct axis and its direction is 90 degrees counterclockwise along the direct axis.

[0070] Specifically, the computer equipment is connected to the vehicle controller via a network. The computer equipment is equipped with corresponding software programs, which can control the vehicle controller. The vehicle controller is connected to the target vehicle's power motor, allowing the computer equipment to directly set the quadrature-axis current, direct-axis current, and electrical angle of the power motor through the software programs. When fault diagnosis of the target vehicle's power motor is required, the operator can directly use the computer equipment to set the quadrature-axis current of the power motor to a first preset value (e.g., 0A), the direct-axis current to a second preset value (e.g., -10A), and control the electrical angle to increase from the first angle to the second angle (e.g., slowly increasing from 0 to 180 degrees) by adjusting the electrical angle value.

[0071] Step 204: As the electrical angle increases from the first angle to the second angle, acquire the quadrature-axis voltage and direct-axis voltage collected at each electrical angle.

[0072] Specifically, when the electrical angle of the motor is increased from a first angle to a second angle by the computer equipment, the quadrature-axis voltage and direct-axis voltage of the motor change continuously. At each electrical angle, the computer equipment can obtain the quadrature-axis voltage at the corresponding electrical angle by performing proportional-integral calculation on the quadrature-axis current of the motor, and obtain the direct-axis voltage at the corresponding electrical angle by performing proportional-integral calculation on the direct-axis current of the motor. The computer equipment can directly read the quadrature-axis voltage and direct-axis voltage at each electrical angle.

[0073] Step 206: Calculate the actual angle between the voltage vector and the current vector based on the quadrature-axis voltage and direct-axis voltage corresponding to each electrical angle.

[0074] Specifically, after acquiring the quadrature-axis voltage and direct-axis voltage at each electrical angle, the computer device processes the quadrature-axis voltage and direct-axis voltage at each electrical angle. For each electrical angle, the computer device obtains a corresponding actual angle between the voltage vector and the current vector. Furthermore, the computer device fits the actual angle between the voltage vector and the current vector at each electrical angle to obtain a definite actual angle between the voltage vector and the current vector.

[0075] Step 208: Obtain the theoretical angle between the voltage vector and the current vector.

[0076] Specifically, after determining the actual angle between the voltage vector and the current vector, the computer equipment also obtains the theoretical angle between the voltage vector and the current vector.

[0077] In one embodiment, obtaining the theoretical angle between the voltage vector and the current vector includes: obtaining the rotational frequency of the direct-axis current vector, the motor inductance, and the motor stator impedance; and calculating the theoretical angle between the voltage vector and the current vector based on the rotational frequency of the direct-axis current vector, the motor inductance, and the motor stator impedance.

[0078] Specifically, after the computer equipment determines the actual angle between the voltage vector and the current vector, it also obtains the rotation frequency of the direct-axis current vector, the motor inductance, and the motor stator impedance. Then, it processes the rotation frequency of the direct-axis current vector, the motor inductance, and the motor stator impedance according to equation (1) to obtain the theoretical angle between the voltage vector and the current vector.

[0079]

[0080] Where f is the rotational frequency of the direct-axis current vector, L is the motor inductance, and R is the motor stator impedance.

[0081] In this embodiment, by acquiring the rotational frequency of the direct-axis current vector, the motor inductance, and the motor stator impedance, the theoretical angle between the voltage vector and the current vector is calculated based on these parameters. This determined theoretical angle between the voltage and current vectors can then be compared with the actual angle, thereby enabling fault diagnosis of the power motor and improving the accuracy of fault diagnosis.

[0082] Step 210: Compare the actual included angle with the theoretical included angle, and determine the fault diagnosis result of the power motor based on the comparison result.

[0083] Specifically, after the computer equipment obtains the theoretical angle between the voltage vector and the current vector, it compares the actual angle with the theoretical angle to obtain a comparison result, which represents the difference between the actual angle and the theoretical angle. Furthermore, the computer equipment can determine the fault diagnosis result of the power motor by judging whether the difference between the actual angle and the theoretical angle is within a preset error range.

[0084] In the aforementioned motor fault diagnosis method, the quadrature-axis current of the motor is controlled to a first preset value, and the direct-axis current is controlled to a second preset value. The electrical angle of the motor is controlled to increase from a first angle to a second angle. During this increase, the quadrature-axis voltage and direct-axis voltage are acquired at each electrical angle. Based on the quadrature-axis voltage and direct-axis voltage corresponding to each electrical angle, the actual angle between the voltage vector and the current vector is calculated. The theoretical angle between the voltage vector and the current vector is then obtained. Finally, the actual angle and the theoretical angle are compared, and the fault diagnosis result of the motor is determined based on the comparison result. In this way, by determining whether the actual angle between the voltage vector and the current vector is within a certain error range compared to the theoretical angle, the fault of the motor can be diagnosed, thereby improving the accuracy of fault diagnosis.

[0085] In one embodiment, the above-mentioned motor fault diagnosis method further includes: determining whether the ignition switch is effective; determining whether the brake is in an active state; determining whether the power inverter is in an active state; determining whether the current controller is in an active state; determining whether the rotor speed is within a preset speed range; if the ignition switch is effective, the brake is in an active state, the power inverter is in an active state, the current controller is in an active state, and the rotor speed is within a preset speed range, then the diagnostic enable condition is determined to be met; if the diagnostic enable condition is met, then the step of controlling the quadrature-axis current of the motor to a first preset value and the direct-axis current to a second preset value is executed.

[0086] Among them, the diagnostic enable condition characterizes the conditions under which fault diagnosis of the power motor can be performed.

[0087] Specifically, before the computer equipment controls the quadrature-axis current of the power motor to a first preset value and the direct-axis current to a second preset value via the vehicle controller, a diagnostic enable condition test of the power motor is required. When the diagnostic enable condition is met, it indicates that fault diagnosis of the power motor can begin. During the diagnostic enable condition test, the computer equipment acquires the operating status of the ignition switch to determine if it is effective; acquires the operating status of the brake to determine if it is active; acquires the operating status of the power inverter to determine if it is active; acquires the operating status of the current controller to determine if it is active; and acquires the rotor speed to determine if it is within a preset speed range. When the computer equipment determines that the ignition switch is effective, the brake is active, the power inverter is active, the current controller is active, and the rotor speed is within the preset speed range, the diagnostic enable condition is met. The computer equipment can then begin executing the steps of controlling the quadrature-axis current of the power motor to the first preset value and the direct-axis current to the second preset value.

[0088] In this embodiment, the following steps are taken: determining whether the ignition switch is active; determining whether the brake is active; determining whether the power inverter is active; determining whether the current controller is active; and determining whether the rotor speed is within a preset speed range. If the ignition switch is active, the brake is active, the power inverter is active, the current controller is active, and the rotor speed is within the preset speed range, then the diagnostic enable condition is met. If the diagnostic enable condition is met, the steps of controlling the quadrature-axis current of the power motor to a first preset value and the direct-axis current to a second preset value are executed. This ensures that the fault diagnosis process of the power motor can proceed smoothly, thereby improving the accuracy of fault diagnosis of the power motor.

[0089] In one embodiment, the actual angle between the voltage vector and the current vector is calculated based on the quadrature-axis voltage and the direct-axis voltage corresponding to each electrical angle, including: processing the quadrature-axis voltage and the direct-axis voltage corresponding to each electrical angle to obtain a first angle between the voltage vector and the positive direction of the direct axis; obtaining a second angle between the current vector and the positive direction of the direct axis; and determining the actual angle between the voltage vector and the current vector based on the first angle and the second angle.

[0090] Specifically, after acquiring the quadrature-axis voltage and direct-axis voltage at each electrical angle, the computer device processes the quadrature-axis voltage and direct-axis voltage at each electrical angle. For each electrical angle, the computer device processes the quadrature-axis voltage and direct-axis voltage corresponding to that electrical angle according to equation (2) to obtain the first angle between the actual voltage vector and the positive direction of the direct axis at that electrical angle. Furthermore, since the direct-axis current is controlled by the computer device to a second preset value (e.g., -10A), which is equivalent to applying a reverse current to the direct axis of the power motor, the computer device can also obtain the second angle θ2 between the actual current vector and the positive direction of the direct axis at that electrical angle. Then, the computer device subtracts the first angle from the second angle according to equation (3) to obtain the actual angle θ0 between the voltage vector and the current vector at each electrical angle. Finally, the computer device fits the actual angle between the voltage vector and the current vector at each electrical angle to obtain the actual angle between the voltage vector and the current vector.

[0091]

[0092] θ0=θ1-θ2 (3)

[0093] Where θ1 is the first angle between the actual voltage vector and the positive direction of the direct axis at each electrical angle, Vq is the quadrature-axis voltage, Vd is the direct-axis voltage, θ2 is the second angle between the actual current vector and the positive direction of the direct axis at each electrical angle, and θ0 is the actual angle between the voltage vector and the current vector.

[0094] In this embodiment, by processing the quadrature-axis voltage and direct-axis voltage corresponding to each electrical angle, a first angle between the voltage vector and the positive direction of the direct axis is obtained. Then, a second angle between the current vector and the positive direction of the direct axis is obtained. Based on the first and second angles, the actual angle between the voltage vector and the current vector is determined. In this way, the determined actual angle between the voltage vector and the current vector can be compared with the theoretical angle, thereby enabling fault diagnosis of the power motor and improving the accuracy of fault diagnosis.

[0095] In one embodiment, the fault diagnosis result of the power motor is determined based on the comparison result, including: if the difference between the actual included angle and the theoretical included angle is within a preset error range, it is determined that the power motor has not malfunctioned; if the difference between the actual included angle and the theoretical included angle is outside the preset error range, the maximum three-phase current is obtained, and the fault diagnosis result is determined based on the maximum three-phase current. The maximum three-phase current is obtained by monitoring the power motor during the process of controlling the electrical angle to increase from the first angle to the second angle.

[0096] It should be noted that each phase of the power motor is equipped with a current sensor. When the computer controls the electrical angle to increase from the first angle to the second angle, the current sensor monitors the current of each phase of the power motor in real time and then transmits the monitored current to the computer. The computer determines the maximum three-phase current from the received current data.

[0097] Specifically, after the computer equipment obtains the theoretical angle between the voltage vector and the current vector, it compares the actual angle with the theoretical angle. If the difference between the actual angle and the theoretical angle is within a preset error range, the computer equipment determines that the power motor is not faulty. If the difference between the actual angle and the theoretical angle is outside the preset error range, the computer equipment also needs to obtain the maximum three-phase current during the process of the control electrical angle increasing from the first angle to the second angle, and then use the maximum three-phase current for further diagnosis.

[0098] In this embodiment, if the difference between the actual and theoretical angles is within a preset error range, the motor is determined to be fault-free. If the difference is outside the preset error range, the maximum three-phase current is obtained during the process of increasing the control angle from the first angle to the second angle, and the fault diagnosis result is determined based on the maximum three-phase current. Thus, by determining whether the actual and theoretical angles between the voltage vector and current vector are within a certain error range, a preliminary fault diagnosis of the motor can be performed, thereby improving the accuracy of fault diagnosis.

[0099] In one embodiment, determining the fault diagnosis result based on the maximum three-phase current includes: comparing the maximum three-phase current with a preset three-phase current threshold; if the maximum three-phase current is less than the preset three-phase current threshold, then determining that the power motor has an open circuit fault; if the maximum three-phase current is greater than the preset three-phase current threshold, then determining that the power motor has a short circuit fault.

[0100] Specifically, after the computer device acquires the maximum three-phase current during the process of increasing the control electrical angle from the first angle to the second angle, it compares the maximum three-phase current with the three-phase current threshold preset in the computer device. If the maximum three-phase current is less than the preset three-phase current threshold, the computer device determines that the power motor has an open circuit fault. If the maximum three-phase current is greater than the preset three-phase current threshold, it determines that the power motor has a short circuit fault.

[0101] In this embodiment, the maximum three-phase current is compared with a preset three-phase current threshold. If the maximum three-phase current is less than the preset three-phase current threshold, an open-circuit fault is determined in the motor; if the maximum three-phase current is greater than the preset three-phase current threshold, a short-circuit fault is determined in the motor. By comparing the maximum three-phase current with the preset three-phase current threshold, the fault of the motor can be further diagnosed, thereby improving the accuracy of fault diagnosis.

[0102] The following is for reference. Figure 3 The method for diagnosing motor faults in this application will be further illustrated with a specific embodiment:

[0103] Step 1: Calculate the actual angle between the voltage vector and the current vector, and record the maximum three-phase current during the process.

[0104] When the computer equipment determines that the ignition switch is active, the brake is activated, the power inverter and current controller are activated, and the rotor speed is greater than the first speed (e.g., -50 rpm) and less than the second speed (e.g., 50 rpm), open and short circuit fault diagnosis is activated. Then, the software program configured on the computer equipment sets the quadrature-axis current to 0, sets the direct-axis current to a constant value (e.g., -10A), and controls the electrical angle to slowly increase from the first angle (e.g., 0) to the second angle (e.g., 180 degrees). The maximum three-phase current is recorded by the current sensor set on each phase of the power motor during the process of the electrical angle slowly increasing from the first angle (e.g., 0) to the second angle (e.g., 180 degrees). When the electrical angle slowly increases from the first angle (e.g., 0) to the second angle (e.g., 180 degrees), the quadrature-axis voltage and direct-axis voltage corresponding to each electrical angle can be directly read from the software program configured on the computer equipment. For each electrical angle, the computer equipment processes the quadrature-axis voltage and direct-axis voltage corresponding to that electrical angle according to equation (2) to obtain the first angle between the actual voltage vector and the positive direction of the direct axis at that electrical angle. Furthermore, the computer device can also obtain the second angle θ2 between the actual current vector and the positive direction of the d-axis at that electrical angle. Then, the computer device subtracts the first angle from the second angle according to equation (3) to obtain the actual angle θ0 between the voltage vector and the current vector at each electrical angle. Finally, the computer device fits the actual angle between the voltage vector and the current vector at each electrical angle to obtain the actual angle between the voltage vector and the current vector.

[0105]

[0106] θ0=θ1-θ2 (3)

[0107] Where θ1 is the first angle between the actual voltage vector and the positive direction of the direct axis at each electrical angle, Vq is the quadrature-axis voltage, Vd is the direct-axis voltage, θ2 is the second angle between the actual current vector and the positive direction of the direct axis at each electrical angle, and θ0 is the actual angle between the voltage vector and the current vector.

[0108] Step 2: Calculate the theoretical angle between the voltage vector and the current vector.

[0109] Specifically, after the computer equipment determines the actual angle between the voltage vector and the current vector, it also obtains the rotation frequency of the direct-axis current vector, the motor inductance, and the motor stator impedance. Then, it processes the rotation frequency of the direct-axis current vector, the motor inductance, and the motor stator impedance according to equation (1) to obtain the theoretical angle between the voltage vector and the current vector.

[0110]

[0111] Where f is the rotational frequency of the direct-axis current vector, L is the motor inductance, and R is the motor stator impedance.

[0112] Step 3: Identify open-circuit and short-circuit faults based on the included angle and the maximum three-phase current compared with the preset three-phase current threshold.

[0113] Specifically, after the computer equipment obtains the actual and theoretical angles between the voltage and current vectors, it compares the actual and theoretical angles. If the difference between the actual and theoretical angles is within a certain error range, the motor is determined to be fault-free. If the difference exceeds a certain error range, further judgment is made based on the maximum three-phase current collected above: if the maximum three-phase current is less than the preset minimum threshold for three-phase current, the motor is determined to have an open-circuit fault; if the maximum three-phase current is greater than the preset minimum threshold for three-phase current, the motor is determined to have a short-circuit fault.

[0114] The aforementioned motor fault diagnosis method controls the quadrature-axis current of the motor to a first preset value and the direct-axis current to a second preset value. It also controls the electrical angle of the motor to increase from a first angle to a second angle. During this increase, the quadrature-axis voltage and direct-axis voltage are acquired at each electrical angle. Based on these voltages, the actual angle between the voltage vector and the current vector is calculated, and the theoretical angle is obtained. Finally, the actual and theoretical angles are compared, and the fault diagnosis result is determined based on the comparison. By determining whether the actual and theoretical angles between the voltage and current vectors are within a certain error range, motor faults can be diagnosed, thus improving the accuracy of fault diagnosis.

[0115] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least a portion of steps or stages in other steps.

[0116] In one embodiment, such as Figure 4 As shown, based on the same inventive concept, this application also provides a power motor fault diagnosis device, including: a control module 401, a first acquisition module 402, a calculation module 403, a second acquisition module 404, and a diagnosis module 405, wherein:

[0117] The control module is used to control the quadrature axis current of the power motor to a first preset value and the direct axis current to a second preset value, and to control the electrical angle of the power motor to increase from the first angle to the second angle.

[0118] The first acquisition module is used to acquire the quadrature-axis voltage and direct-axis voltage collected at each electrical angle as the electrical angle increases from the first angle to the second angle.

[0119] The calculation module is used to calculate the actual angle between the voltage vector and the current vector based on the quadrature-axis voltage and direct-axis voltage corresponding to each electrical angle.

[0120] The second acquisition module is used to obtain the theoretical angle between the voltage vector and the current vector.

[0121] The diagnostic module is used to compare the actual included angle with the theoretical included angle and determine the fault diagnosis result of the power motor based on the comparison result.

[0122] In one embodiment, the aforementioned motor fault diagnosis device further includes a determination module, used to determine whether the ignition switch is effective; whether the brake is in an active state; whether the power inverter is in an active state; whether the current controller is in an active state; and whether the rotor speed is within a preset speed range. If the ignition switch is effective, the brake is in an active state, the power inverter is in an active state, the current controller is in an active state, and the rotor speed is within the preset speed range, then the diagnostic enable condition is determined to be met. If the diagnostic enable condition is met, the control module executes the step of controlling the quadrature-axis current of the motor to a first preset value and the direct-axis current to a second preset value.

[0123] In one embodiment, the calculation module is further configured to process the quadrature-axis voltage and direct-axis voltage corresponding to each electrical angle to obtain a first angle between the voltage vector and the positive direction of the direct axis; obtain a second angle between the current vector and the positive direction of the direct axis; and determine the actual angle between the voltage vector and the current vector based on the first angle and the second angle.

[0124] In one embodiment, the second acquisition module is further configured to acquire the direct-axis current vector rotation frequency, motor inductance, and motor stator impedance; and calculate the theoretical angle between the voltage vector and the current vector based on the direct-axis current vector rotation frequency, motor inductance, and motor stator impedance.

[0125] In one embodiment, the aforementioned power motor fault diagnosis device further includes a third acquisition module. The diagnosis module is further configured to determine that the power motor has not malfunctioned if the difference between the actual angle and the theoretical angle is within a preset error range; if the difference between the actual angle and the theoretical angle is outside the preset error range, the third acquisition module acquires the maximum three-phase current. The diagnosis module is further configured to determine the fault diagnosis result based on the maximum three-phase current. The maximum three-phase current is obtained by monitoring the power motor during the process of controlling the electrical angle to increase from the first angle to the second angle.

[0126] In one embodiment, the diagnostic module is further configured to compare the maximum three-phase current with a preset three-phase current threshold; if the maximum three-phase current is less than the preset three-phase current threshold, it is determined that the power motor has an open-circuit fault; if the maximum three-phase current is greater than the preset three-phase current threshold, it is determined that the power motor has a short-circuit fault.

[0127] Each module in the aforementioned motor fault diagnosis device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of the computer device in software form, so that the processor can call and execute the corresponding operations of each module.

[0128] In one embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 5 As shown, the computer device includes a processor, memory, input / output interface, communication interface, display unit, and input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interface. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The input / output interface is used for exchanging information between the processor and external devices. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, NFC (Near Field Communication), or other technologies. When the computer program is executed by the processor, it implements a method for diagnosing motor faults. The display unit is used to form a visually visible image and can be a display screen, projection device, or virtual reality imaging device. The display screen can be an LCD screen or an e-ink screen. The input device of the computer device can be a touch layer covering the display screen, or buttons, trackballs, or touchpads set on the casing of the computer device, or external keyboards, touchpads, or mice, etc.

[0129] Those skilled in the art will understand that Figure 5 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0130] In one embodiment, a computer device is provided, including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to perform the following steps: controlling the quadrature-axis current of a power motor to a first preset value and the direct-axis current to a second preset value, and controlling the electrical angle of the power motor to increase from a first angle to a second angle; during the process of the electrical angle increasing from the first angle to the second angle, acquiring the quadrature-axis voltage and direct-axis voltage collected at each electrical angle; calculating the actual angle between the voltage vector and the current vector based on the quadrature-axis voltage and the direct-axis voltage corresponding to each electrical angle; acquiring the theoretical angle between the voltage vector and the current vector; comparing the actual angle with the theoretical angle, and determining the fault diagnosis result of the power motor based on the comparison result.

[0131] In one embodiment, when the processor executes the computer program, it further performs the following steps: determining whether the ignition switch is active; determining whether the brake is active; determining whether the power inverter is active; determining whether the current controller is active; determining whether the rotor speed is within a preset speed range; if the ignition switch is active, the brake is active, the power inverter is active, the current controller is active, and the rotor speed is within the preset speed range, then it is determined that the diagnostic enable condition is met; if the diagnostic enable condition is met, then the step of controlling the quadrature-axis current of the power motor to a first preset value and the direct-axis current to a second preset value is executed.

[0132] In one embodiment, when the processor executes the computer program, it further performs the following steps: processing the quadrature-axis voltage and direct-axis voltage corresponding to each electrical angle to obtain a first angle between the voltage vector and the positive direction of the direct axis; obtaining a second angle between the current vector and the positive direction of the direct axis; and determining the actual angle between the voltage vector and the current vector based on the first angle and the second angle.

[0133] In one embodiment, when the processor executes the computer program, it also performs the following steps: obtaining the direct-axis current vector rotation frequency, motor inductance, and motor stator impedance; and calculating the theoretical angle between the voltage vector and the current vector based on the direct-axis current vector rotation frequency, motor inductance, and motor stator impedance.

[0134] In one embodiment, when the processor executes the computer program, it further implements the following steps: if the difference between the actual included angle and the theoretical included angle is within a preset error range, it is determined that the power motor has not malfunctioned; if the difference between the actual included angle and the theoretical included angle is outside the preset error range, the maximum three-phase current is obtained, and the fault diagnosis result is determined based on the maximum three-phase current. The maximum three-phase current is obtained by monitoring the power motor during the process of controlling the electrical angle to increase from the first angle to the second angle.

[0135] In one embodiment, when the processor executes the computer program, it further performs the following steps: comparing the maximum three-phase current with a preset three-phase current threshold; if the maximum three-phase current is less than the preset three-phase current threshold, it determines that the power motor has an open-circuit fault; if the maximum three-phase current is greater than the preset three-phase current threshold, it determines that the power motor has a short-circuit fault.

[0136] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, it performs the following steps: controlling the quadrature-axis current of the power motor to a first preset value and the direct-axis current to a second preset value, and controlling the electrical angle of the power motor to increase from a first angle to a second angle; during the process of the electrical angle increasing from the first angle to the second angle, acquiring the quadrature-axis voltage and direct-axis voltage collected at each electrical angle; calculating the actual angle between the voltage vector and the current vector based on the quadrature-axis voltage and the direct-axis voltage corresponding to each electrical angle; acquiring the theoretical angle between the voltage vector and the current vector; comparing the actual angle with the theoretical angle, and determining the fault diagnosis result of the power motor based on the comparison result.

[0137] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: determining whether the ignition switch is active; determining whether the brake is active; determining whether the power inverter is active; determining whether the current controller is active; determining whether the rotor speed is within a preset speed range; if the ignition switch is active, the brake is active, the power inverter is active, the current controller is active, and the rotor speed is within the preset speed range, then it is determined that the diagnostic enable condition is met; if the diagnostic enable condition is met, then the step of controlling the quadrature-axis current of the power motor to a first preset value and the direct-axis current to a second preset value is executed.

[0138] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: processing the quadrature-axis voltage and direct-axis voltage corresponding to each electrical angle to obtain a first angle between the voltage vector and the positive direction of the direct axis; obtaining a second angle between the current vector and the positive direction of the direct axis; and determining the actual angle between the voltage vector and the current vector based on the first angle and the second angle.

[0139] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: obtaining the rotation frequency of the direct-axis current vector, the motor inductance, and the motor stator impedance; and calculating the theoretical angle between the voltage vector and the current vector based on the rotation frequency of the direct-axis current vector, the motor inductance, and the motor stator impedance.

[0140] In one embodiment, when the computer program is executed by the processor, it further implements the following steps: if the difference between the actual included angle and the theoretical included angle is within a preset error range, it is determined that the power motor has not malfunctioned; if the difference between the actual included angle and the theoretical included angle is outside the preset error range, the maximum three-phase current is obtained, and the fault diagnosis result is determined based on the maximum three-phase current. The maximum three-phase current is obtained by monitoring the power motor during the process of controlling the electrical angle to increase from the first angle to the second angle.

[0141] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: comparing the maximum three-phase current with a preset three-phase current threshold; if the maximum three-phase current is less than the preset three-phase current threshold, then determining that the power motor has an open-circuit fault; if the maximum three-phase current is greater than the preset three-phase current threshold, then determining that the power motor has a short-circuit fault.

[0142] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, performs the following steps: controlling the quadrature-axis current of a power motor to a first preset value and the direct-axis current to a second preset value, and controlling the electrical angle of the power motor to increase from a first angle to a second angle; during the process of the electrical angle increasing from the first angle to the second angle, acquiring the quadrature-axis voltage and direct-axis voltage collected at each electrical angle; calculating the actual angle between the voltage vector and the current vector based on the quadrature-axis voltage and direct-axis voltage corresponding to each electrical angle; acquiring the theoretical angle between the voltage vector and the current vector; comparing the actual angle with the theoretical angle, and determining the fault diagnosis result of the power motor based on the comparison result.

[0143] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: determining whether the ignition switch is active; determining whether the brake is active; determining whether the power inverter is active; determining whether the current controller is active; determining whether the rotor speed is within a preset speed range; if the ignition switch is active, the brake is active, the power inverter is active, the current controller is active, and the rotor speed is within the preset speed range, then it is determined that the diagnostic enable condition is met; if the diagnostic enable condition is met, then the step of controlling the quadrature-axis current of the power motor to a first preset value and the direct-axis current to a second preset value is executed.

[0144] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: processing the quadrature-axis voltage and direct-axis voltage corresponding to each electrical angle to obtain a first angle between the voltage vector and the positive direction of the direct axis; obtaining a second angle between the current vector and the positive direction of the direct axis; and determining the actual angle between the voltage vector and the current vector based on the first angle and the second angle.

[0145] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: obtaining the rotational frequency of the direct-axis current vector, the motor inductance, and the motor stator impedance; and calculating the theoretical angle between the voltage vector and the current vector based on the rotational frequency of the direct-axis current vector, the motor inductance, and the motor stator impedance.

[0146] In one embodiment, when the computer program is executed by the processor, it further implements the following steps: if the difference between the actual included angle and the theoretical included angle is within a preset error range, it is determined that the power motor has not malfunctioned; if the difference between the actual included angle and the theoretical included angle is outside the preset error range, the maximum three-phase current is obtained, and the fault diagnosis result is determined based on the maximum three-phase current. The maximum three-phase current is obtained by monitoring the power motor during the process of controlling the electrical angle to increase from the first angle to the second angle.

[0147] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: comparing the maximum three-phase current with a preset three-phase current threshold; if the maximum three-phase current is less than the preset three-phase current threshold, determining that the power motor has an open-circuit fault; if the maximum three-phase current is greater than the preset three-phase current threshold, determining that the power motor has a short-circuit fault.

[0148] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0149] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0150] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for diagnosing faults in a power motor, characterized in that, The method includes: The quadrature axis current of the power motor is controlled to a first preset value, the direct axis current is controlled to a second preset value, and the electrical angle of the power motor is controlled to increase from the first angle to the second angle. During the process of the electrical angle increasing from the first angle to the second angle, the quadrature-axis voltage and direct-axis voltage collected at each electrical angle are obtained; The actual angle between the voltage vector and the current vector is calculated based on the quadrature-axis voltage and direct-axis voltage corresponding to each electrical angle. Obtain the theoretical angle between the voltage vector and the current vector; The actual included angle is compared with the theoretical included angle, and the fault diagnosis result of the power motor is determined based on the comparison result; The step of determining the fault diagnosis result of the power motor based on the comparison result includes: If the difference between the actual included angle and the theoretical included angle is within the preset error range, then it is determined that the power motor has not malfunctioned; If the difference between the actual included angle and the theoretical included angle is outside the preset error range, the maximum three-phase current is obtained, and the fault diagnosis result is determined based on the maximum three-phase current. The maximum three-phase current is obtained by monitoring the power motor during the process of controlling the electrical angle to increase from the first angle to the second angle.

2. The method according to claim 1, characterized in that, The method further includes: Determine if the ignition switch is working; Determine if the brake is in an active state; Determine if the power inverter is active. Determine if the current controller is active; Determine if the rotor speed is within the preset speed range; If the ignition switch is active, the brake is activated, the power inverter is activated, the current controller is activated, and the rotor speed is within the preset speed range, then the diagnostic enable condition is determined to be met. If the diagnostic enable condition is met, then the step of controlling the quadrature axis current of the power motor to be a first preset value and the direct axis current to be a second preset value is executed.

3. The method according to claim 1, characterized in that, The calculation of the actual angle between the voltage vector and the current vector based on the quadrature-axis voltage and direct-axis voltage corresponding to each electrical angle includes: Process the quadrature-axis voltage and direct-axis voltage corresponding to each electrical angle to obtain the first angle between the voltage vector and the positive direction of the direct axis; Obtain the second angle between the current vector and the positive direction of the direct axis; Based on the first included angle and the second included angle, the actual included angle between the voltage vector and the current vector is determined.

4. The method according to claim 1, characterized in that, The acquisition of the theoretical angle between the voltage vector and the current vector includes: Obtain the direct-axis current vector rotation frequency, motor inductance, and motor stator impedance; The theoretical angle between the voltage vector and the current vector is calculated based on the rotation frequency of the direct-axis current vector, the motor inductance, and the motor stator impedance.

5. The method according to any one of claims 1-4, characterized in that, The method of determining the fault diagnosis result based on the maximum three-phase current includes: Compare the maximum three-phase current with the preset three-phase current threshold; If the maximum three-phase current is less than the preset three-phase current threshold, then it is determined that the power motor has an open circuit fault. If the maximum three-phase current is greater than the preset three-phase current threshold, then a short-circuit fault is determined to have occurred in the power motor.

6. A power motor fault diagnosis device, characterized in that, The device includes: The control module is used to control the quadrature axis current of the power motor to a first preset value and the direct axis current to a second preset value, and to control the electrical angle of the power motor to increase from the first angle to the second angle. The first acquisition module is used to acquire the quadrature-axis voltage and direct-axis voltage collected at each electrical angle as the electrical angle increases from the first angle to the second angle. The calculation module is used to calculate the actual angle between the voltage vector and the current vector based on the quadrature-axis voltage and direct-axis voltage corresponding to each electrical angle. The second acquisition module is used to acquire the theoretical angle between the voltage vector and the current vector; The diagnostic module is used to compare the actual included angle with the theoretical included angle, and determine the fault diagnosis result of the power motor based on the comparison result; The power motor fault diagnosis device further includes a third acquisition module; the diagnosis module is configured to: determine that the power motor has not malfunctioned if the difference between the actual angle and the theoretical angle is within a preset error range; and acquire the maximum three-phase current if the difference between the actual angle and the theoretical angle is outside the preset error range. The diagnostic module includes a method for determining fault diagnosis results based on the maximum three-phase current, which is obtained by monitoring the power motor during the process of controlling the electrical angle to increase from a first angle to a second angle.

7. The power motor fault diagnosis device according to claim 6, characterized in that, The diagnostic module further includes a function to compare the maximum three-phase current with a preset three-phase current threshold; if the maximum three-phase current is less than the preset three-phase current threshold, then the power motor is determined to have an open-circuit fault; if the maximum three-phase current is greater than the preset three-phase current threshold, then the power motor is determined to have a short-circuit fault.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 5.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 5.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 5.

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