Method and device for processing three-phase current imbalance of motor, vehicle-mounted equipment and vehicle

Abstract

The present disclosure relates to a motor three-phase current imbalance processing method and device, a vehicle-mounted device, a vehicle, a storage medium and a product. The motor three-phase current imbalance processing method comprises: in response to the three-phase current imbalance of the motor, obtaining a first operating parameter; determining a first compensation current corresponding to the first operating parameter based on a first mapping relationship; compensating a preset current of the motor based on the first compensation current to obtain a compensated current of the motor; and controlling the motor to operate based on the compensated current. Through the method provided in the embodiments of the present disclosure, the three-phase current imbalance of the motor can be weakened or eliminated, and thus the noise, vibration and other problems caused by the three-phase current imbalance of the motor to the device where the motor is located can be weakened or eliminated.

Description

Technical Field

[0001] This disclosure relates to the field of motor technology, specifically to a method, apparatus, vehicle-mounted equipment, vehicle, storage medium, and product for handling three-phase current imbalance in motors. Background Technology

[0002] Electric motors are the power source for most devices; therefore, the operating condition of a motor significantly impacts the quality of work on the equipment it powers. For example, in a vehicle, an imbalance in the three-phase current of the motor can cause abnormal vibrations and increased noise within the electric vehicle, affecting the user's driving comfort. Summary of the Invention

[0003] One objective of this disclosure is to provide a method for handling three-phase current imbalance in a motor, so as to solve the problems of noise and vibration caused by three-phase current imbalance in a motor in the prior art; a second objective is to provide a device for handling three-phase current imbalance in a motor; a third objective is to provide an on-board device; a fourth objective is to provide a vehicle; a fifth objective is to provide a computer-readable storage medium; and a sixth objective is to provide a computer program product.

[0004] To achieve the above objectives, the technical solution adopted in this disclosure is as follows: In a first aspect, this disclosure provides a method for handling the problem of three-phase current imbalance in a motor, comprising: in response to the three-phase current imbalance of the motor, acquiring a first operating parameter; wherein the first operating parameter includes the degree of imbalance of the three-phase current of the motor and an influence parameter corresponding to at least one phase current of the three-phase current; determining a first compensation current corresponding to the first operating parameter based on a first mapping relationship; wherein the first mapping relationship includes a mapping relationship between the operating parameter and the compensation current; compensating a preset current of the motor based on the first compensation current to obtain a compensated current of the motor; and controlling the operation of the motor based on the compensated current.

[0005] In this embodiment, when a motor has a three-phase current imbalance problem, a first compensation current for the motor is determined based on the degree of imbalance of the three-phase current and / or the influence parameters corresponding to at least one phase current. A preset current for the motor is then compensated based on this first compensation current. This can reduce or eliminate the three-phase current imbalance of the motor, thereby reducing or eliminating vibration, noise, and other problems caused by the motor imbalance to the equipment in which it is located.

[0006] In some embodiments, the influencing parameter is a parameter that causes the amplitude and / or phase of at least one phase current to deviate from the equilibrium value, where the equilibrium value is the target amplitude and target phase of at least one phase current when the three phase currents are in balance.

[0007] In some embodiments, the influencing parameters include at least one of the following: motor speed; motor temperature; motor bus voltage fluctuation value; and pedal opening of the vehicle in which the motor is located.

[0008] In this embodiment of the disclosure, the first compensation current is determined based on multiple influencing parameters and the imbalance of the three-phase current of the motor, which can improve the accuracy of the determination of the first compensation current.

[0009] In some embodiments, the first mapping relationship includes a first sub-mapping relationship and a second sub-mapping relationship, wherein the first sub-mapping relationship includes a mapping relationship between operating parameters and compensation current gain values, and the second sub-mapping relationship includes a mapping relationship between compensation current gain values ​​and compensation current; determining the first compensation current corresponding to the first operating parameters based on the first mapping relationship includes: determining the target compensation current gain value corresponding to the first operating parameters based on the first sub-mapping relationship; determining the compensation current corresponding to the target compensation current gain value based on the second sub-mapping relationship; and determining the compensation current corresponding to the target compensation current gain value as the first compensation current.

[0010] In this embodiment of the disclosure, by pre-storing the first sub-mapping relationship and the second sub-mapping relationship, and after obtaining the first operating parameters, determining the first compensation current through the first sub-mapping relationship and the second sub-mapping relationship, the efficiency of determining the compensation current can be improved, and the computational load of the determination process of the first compensation current can be reduced.

[0011] In some embodiments, the motor's preset current is compensated based on the first compensation current to obtain the motor's compensated current, including: in response to the first compensation current being the motor's d-axis first compensation current and q-axis first compensation current, converting the first compensation current into the compensation current of each phase of the three-phase current; obtaining the fundamental component from the compensation current of each phase current; determining the d-axis second compensation current and the q-axis second compensation current based on the fundamental components of the three-phase current compensation current; compensating the preset current of the d-axis based on the second compensation current of the d-axis, and compensating the preset current of the q-axis based on the second compensation current of the q-axis, to obtain the compensated current.

[0012] In this embodiment of the present disclosure, the on-board equipment obtains the fundamental component from the compensation current of each phase current, and determines the second compensation current on the d-axis and the second compensation current on the q-axis based on the fundamental components of the compensation current of the three-phase current. Thus, the obtained second compensation current is the fundamental compensation current, which can reduce the impact of compensation currents with higher harmonics being superimposed on the preset current.

[0013] In some embodiments, the method further includes: acquiring the force wave amplitude of the motor; determining a first gain coefficient corresponding to the three-phase current of the motor based on the force wave amplitude and a first response signal value corresponding to the force wave amplitude; wherein the first response signal value includes noise value and / or vibration acceleration value caused by the imbalance of the three-phase current of the motor before current compensation is performed on the motor; determining the degree of imbalance of the three-phase current based on the difference between the first gain coefficient and the second gain coefficient, wherein the second gain coefficient is the gain coefficient corresponding to the three-phase current of the motor in a balanced state.

[0014] In this embodiment, when the motor has a three-phase current imbalance, an additional negative-sequence magnetic field excitation is introduced at the 2P-order frequency, causing an abnormal increase in the actual first response signal value, which in turn leads to an increase in the difference between the first gain coefficient and the second gain coefficient. Therefore, based on the first response signal value and the force wave amplitude of the motor, the first gain coefficient corresponding to the three-phase current of the motor in an unbalanced state can be determined. Thus, the difference between the first gain coefficient and the second gain coefficient can accurately reflect the degree of imbalance of the three-phase current of the motor.

[0015] In some embodiments, determining a first gain coefficient corresponding to the three-phase current of the motor based on the force wave amplitude and a first response signal value corresponding to the force wave amplitude includes: determining a candidate gain coefficient based on the force wave amplitude using a recursive least squares method and / or a recurrent neural network; determining a second response signal value based on the candidate gain coefficient and the force wave amplitude using a second mapping relationship; the second mapping relationship is a mapping relationship between the gain coefficient and the force wave amplitude and the response signal value; and determining the candidate gain coefficient as the first gain coefficient if the difference between the second response signal value and the first response signal value is less than or equal to a difference threshold.

[0016] In this embodiment of the disclosure, if the difference between the second response signal and the first response signal is less than or equal to a difference threshold, it indicates that the currently calculated candidate gain coefficient is the same as or similar to the actual gain coefficient caused by the first response signal value. In this case, using the candidate gain coefficient as the first gain coefficient to determine the imbalance of the three-phase current of the motor can further improve the accuracy of determining the imbalance of the three-phase current.

[0017] In some embodiments, obtaining the force wave amplitude of the motor includes: determining the current operating condition of the motor based on a second operating parameter of the motor, wherein at least one operating parameter included in the second operating parameter is different from the first operating parameter; and obtaining the force wave amplitude of the motor in response to the current operating condition being a preset operating condition.

[0018] In this embodiment of the disclosure, when the current operating condition of the motor is a preset operating condition that is prone to causing three-phase current imbalance, the amplitude of the force wave of the motor is obtained, the degree of imbalance of the three-phase current of the motor is determined based on the obtained amplitude of the force wave, and the first compensation current is determined based on the degree of imbalance of the three-phase current of the motor to apply to the preset current of the motor, so as to realize the timely detection and timely resolution of the three-phase current imbalance problem of the motor.

[0019] In some embodiments, in response to the current operating condition of the motor being a preset operating condition, the force wave amplitude of the motor is obtained, including: in response to the current operating condition being a preset operating condition, determining the operating state of the motor; and in response to the motor being in a stable operating state, obtaining the force wave amplitude of the motor.

[0020] In this embodiment of the disclosure, after determining that the motor is in a stable operating state, the vehicle-mounted equipment further obtains the force wave amplitude of the motor, which can improve the accuracy of the obtained force wave amplitude, and thus improve the accuracy of the unbalance of the three-phase current determined based on the force wave amplitude.

[0021] In some embodiments, the method further includes: after controlling the motor to operate based on the compensated current, acquiring a third response signal value of the motor; wherein the third response signal value includes a noise value and / or vibration acceleration value caused by the three-phase current imbalance of the motor; in response to the third response signal value decreasing by a magnitude greater than or equal to a first response signal value, continuing to compensate the preset current of the motor based on a first compensation current; the first response signal value includes a noise value and / or vibration acceleration value caused by the three-phase current imbalance of the motor before current compensation is performed on the motor; in response to the third response signal value decreasing by a magnitude less than the first response signal value, adjusting the determination method of the first compensation current, redetermining the first compensation current based on the adjusted determination method, and compensating the preset current of the motor based on the redetermined first compensation current.

[0022] In this embodiment, after the on-board device controls the motor to run based on the compensated current, it can also acquire a third response signal value and calculate the reduction magnitude of the third response signal value relative to the first response signal value. This reduction magnitude characterizes the compensation effect of the first compensation current on the imbalance of the motor's three-phase current. If the reduction magnitude of the third response signal value relative to the first response signal value is greater than or equal to a first magnitude threshold, it indicates that the motor's operation effect after compensation based on the first compensation current has achieved the expected effect. If the reduction magnitude of the third response signal value relative to the first response signal value is less than the first magnitude threshold, it indicates that the current current compensation strategy may not be suitable. In this case, the compensation strategy is adjusted, that is, the method of determining the first compensation current is adjusted. In this way, the efficiency of obtaining a suitable first compensation current can be improved, thereby improving the solution effect of the motor's three-phase current imbalance problem.

[0023] In some embodiments, the first operating parameter is obtained according to a preset period; in response to the decrease of the third response signal value relative to the first response signal value being less than a first amplitude threshold, the method for determining the first compensation current is adjusted, and the first compensation current is re-determined based on the adjusted method, including: in response to the decrease of the third response signal value relative to the first response signal value being less than the first amplitude threshold, obtaining the number of invalid compensations of the preset current, wherein the number of invalid compensations is the number of times the decrease of the third response signal value relative to the first response signal value is less than the first amplitude threshold when the preset current is compensated and the motor is operated based on the compensated current; in response to the number of invalid compensations being less than or equal to the number threshold, adjusting the preset period, and re-determining the first compensation current based on the first operating parameter obtained according to the adjusted preset period; in response to the number of invalid compensations being greater than the number threshold, attenuating the obtained first compensation current.

[0024] In this embodiment, if the number of times the on-board device performs ineffective compensation on the preset current of the motor based on the first compensation current exceeds a threshold, the obtained first compensation current is attenuated, and the preset current of the motor is compensated based on the attenuated first compensation current. This reduces the probability of motor instability caused by overcompensation of the preset current.

[0025] In some embodiments, the method further includes: outputting a prompt message, wherein the prompt message is used to indicate possible causes of the three-phase current imbalance.

[0026] In this embodiment of the disclosure, not all causes of three-phase current imbalance in the motor can be alleviated or resolved by the first compensation current. Therefore, if the three-phase current imbalance problem in the motor cannot be resolved or alleviated by repeatedly executing the methods provided in this embodiment of the disclosure, a prompt message can be output to indicate the possible causes of the three-phase current imbalance problem in the motor, which can help maintenance personnel quickly find the cause of the fault.

[0027] In some embodiments, determining the first compensation current corresponding to the first operating parameter based on the first mapping relationship includes: in response to the three-phase current imbalance of the motor, and the imbalance degree of the three-phase current is greater than the imbalance degree threshold, determining the first compensation current corresponding to the first operating parameter based on the first mapping relationship.

[0028] In this embodiment, the on-board device determines an imbalance threshold based on different operating conditions of the motor and / or the load condition of the equipment where the motor is located, and uses this threshold to determine whether the three-phase current of the motor is unbalanced. Compared with using a single imbalance threshold to determine whether the three-phase current of the motor is unbalanced, this method improves the accuracy of the determination. Furthermore, the on-board device adjusts the determined imbalance threshold based on the historical operating conditions of the motor and / or the equipment where the motor is located, and uses the adjusted threshold to determine whether the motor has a three-phase current imbalance. This allows for early warning of three-phase current imbalance caused by motor aging.

[0029] In some embodiments, in response to a three-phase current imbalance in the motor, and the degree of imbalance of the three-phase current is greater than an imbalance threshold, determining a first compensation current corresponding to a first operating parameter based on a first mapping relationship includes: in response to a three-phase current imbalance in the motor, and the degree of imbalance of the three-phase current is greater than an imbalance threshold, determining the imbalance range in which the imbalance is located; in response to the imbalance being within a first imbalance range, determining a first compensation current corresponding to a first operating parameter based on the first mapping relationship, wherein the lower limit of the first imbalance range is greater than the upper limit of the second imbalance range.

[0030] In this embodiment, if the imbalance of the three-phase current in the vehicle-mounted equipment is within a first imbalance range, it indicates that the current imbalance of the three-phase current in the motor is quite severe. At this time, the vehicle-mounted equipment determines a first compensation current based on the motor's first operating parameters, compensates the motor's preset current based on the first compensation current, and operates the motor based on the compensated current. This can promptly resolve or alleviate the three-phase current imbalance problem in the motor.

[0031] In addition, when the imbalance of the three-phase current is within the first imbalance range, the first compensation current is determined based on the first operating parameters of the motor, and the preset current of the motor is compensated based on the first compensation current, and the motor is run based on the compensated current. However, when the imbalance of the three-phase current is within the second imbalance range, the preset current of the motor is not compensated. This can also reduce the computational pressure on the on-board equipment caused by determining the first compensation current due to the slight imbalance of the motor's three-phase current.

[0032] Secondly, this disclosure provides a device for processing three-phase current imbalance in a motor, comprising: a first acquisition module configured to acquire first operating parameters in response to three-phase current imbalance in the motor; wherein the first operating parameters include the degree of imbalance of the three-phase current in the motor and an influence parameter corresponding to at least one phase current in the three-phase current; a first determination module configured to determine a first compensation current corresponding to the first operating parameters based on a first mapping relationship; wherein the first mapping relationship includes a mapping relationship between the operating parameters and the compensation current; a compensation module configured to compensate a preset current of the motor based on the first compensation current to obtain a compensated current in the motor; and a control module configured to control the operation of the motor based on the compensated current.

[0033] In some embodiments, the influencing parameter is a parameter that causes the amplitude and / or phase of at least one phase current to deviate from the equilibrium value, where the equilibrium value is the target amplitude and target phase of at least one phase current when the three phase currents are in balance.

[0034] In some embodiments, the influencing parameters include at least one of the following: motor speed; motor temperature; motor bus voltage fluctuation value; and pedal opening of the vehicle in which the motor is located.

[0035] In some embodiments, the first mapping relationship includes a first sub-mapping relationship and a second sub-mapping relationship, wherein the first sub-mapping relationship includes a mapping relationship between operating parameters and compensation current gain value, and the second sub-mapping relationship includes a mapping relationship between compensation current gain value and compensation current; the first determining module is configured to: determine a target compensation current gain value corresponding to the first operating parameters based on the first sub-mapping relationship; determine a compensation current corresponding to the target compensation current gain value based on the second sub-mapping relationship; and determine the compensation current corresponding to the target compensation current gain value as the first compensation current.

[0036] In some embodiments, the compensation module is configured to: in response to the first compensation current being the first compensation current of the motor's d-axis and the first compensation current of the motor's q-axis, convert the first compensation current into the compensation current of each phase of the three-phase current; obtain the fundamental component from the compensation current of each phase current; determine the second compensation current of the d-axis and the second compensation current of the q-axis based on the fundamental components of the compensation current of the three-phase current; compensate the preset current of the d-axis based on the second compensation current of the d-axis, and compensate the preset current of the q-axis based on the second compensation current of the q-axis, to obtain the compensated current.

[0037] In some embodiments, the device further includes: a second acquisition module configured to acquire the force wave amplitude of the motor; a second determination module configured to determine a first gain coefficient corresponding to the three-phase current of the motor based on the force wave amplitude and a first response signal value corresponding to the force wave amplitude; wherein the first response signal value includes noise value and / or vibration acceleration value caused by the three-phase current imbalance of the motor before current compensation is performed on the motor; and a third determination module configured to determine the degree of imbalance of the three-phase current based on the difference between the first gain coefficient and the second gain coefficient, wherein the second gain coefficient is the gain coefficient corresponding to the three-phase current when the motor is in a balanced state.

[0038] In some embodiments, the second determining module is configured to: determine candidate gain coefficients based on the force wave amplitude using a recursive least squares method and / or a recurrent neural network; determine a second response signal value based on the candidate gain coefficients and the force wave amplitude using a second mapping relationship; the second mapping relationship is a mapping relationship between the gain coefficients and the force wave amplitude and the response signal value; and determine the candidate gain coefficients as the first gain coefficients if the difference between the second response signal value and the first response signal value is less than or equal to a difference threshold.

[0039] In some embodiments, the second acquisition module is configured to: determine the current operating condition of the motor based on the second operating parameters of the motor, wherein at least one operating parameter included in the second operating parameters is different from the first operating parameters; and acquire the force wave amplitude of the motor in response to the current operating condition being a preset operating condition.

[0040] In some embodiments, the second acquisition module is configured to: determine the operating state of the motor in response to the current operating condition being a preset operating condition; and acquire the force wave amplitude of the motor in response to the motor being in a stable operating state.

[0041] In some embodiments, the device further includes: a third acquisition module configured to acquire a third response signal value of the motor after the motor is controlled to run based on the compensated current; wherein the third response signal value includes a noise value and / or vibration acceleration value caused by the three-phase current imbalance of the motor; a continued compensation module configured to continue to compensate the preset current of the motor based on the first compensation current in response to the third response signal value decreasing by a magnitude greater than or equal to a first amplitude threshold; the first response signal value includes a noise value and / or vibration acceleration value caused by the three-phase current imbalance of the motor before current compensation is performed on the motor; and an adjustment module configured to adjust the determination method of the first compensation current in response to the third response signal value decreasing by a magnitude less than the first amplitude threshold, and redetermine the first compensation current based on the adjusted determination method, and compensate the preset current of the motor based on the redetermined first compensation current.

[0042] In some embodiments, the first operating parameter is obtained according to a preset period; the adjustment module is configured to: in response to the third response signal value decreasing less than the first response signal value by a factor of less than a first amplitude threshold, obtain the number of invalid compensations of the preset current, wherein the number of invalid compensations is the number of times the decrease of the third response signal value relative to the first response signal value is less than the first amplitude threshold when the preset current is compensated and the motor is operated based on the compensated current; in response to the number of invalid compensations being less than or equal to the number of times threshold, adjust the preset period and redetermine the first compensation current based on the first operating parameter obtained according to the adjusted preset period; in response to the number of invalid compensations being greater than the number of times threshold, attenuate the obtained first compensation current.

[0043] In some embodiments, the device further includes an output module configured to output a prompt message, wherein the prompt message is used to indicate possible causes of three-phase current imbalance.

[0044] In some embodiments, the first determining module is configured to: in response to the three-phase current imbalance of the motor, and the imbalance degree of the three-phase current is greater than the imbalance degree threshold, determine the first compensation current corresponding to the first operating parameter based on the first mapping relationship.

[0045] In some embodiments, the first determining module is configured to: in response to the three-phase current imbalance of the motor and the imbalance degree of the three-phase current is greater than the imbalance degree threshold, determine the imbalance degree range in which the imbalance degree is located; in response to the imbalance degree being within the first imbalance degree range, determine the first compensation current corresponding to the first operating parameter based on the first mapping relationship, wherein the lower limit of the first imbalance degree range is greater than the upper limit of the second imbalance degree range.

[0046] Thirdly, this disclosure provides an in-vehicle device, including a memory and one or more processors, wherein the memory stores a computer program that, when executed by the in-vehicle device, implements the method described in the first aspect.

[0047] Fourthly, this disclosure provides a vehicle, including onboard equipment and an electric motor.

[0048] Fifthly, this disclosure provides a computer-readable storage medium storing executable instructions, wherein when executed by a processor, the executable instructions implement the method described in the first aspect.

[0049] In a sixth aspect, this disclosure provides a computer program product, including a computer program or instructions, which, when executed by a processor, implement the method described in the first aspect.

[0050] It should be noted that the technical effects of aspects two through six can be referred to in the detailed description of aspect one above, and will not be repeated here. Attached Figure Description

[0051] Figure 1 This is a flowchart illustrating a method for handling three-phase current imbalance in a motor according to an exemplary embodiment. Figure 2 This is a flowchart illustrating a method for handling three-phase current imbalance in a motor according to another exemplary embodiment; Figure 3 This is a schematic diagram illustrating a comparison of the noise signal values ​​of a motor before and after current compensation, according to an exemplary embodiment. Figure 4 This is a flowchart illustrating a method for handling three-phase current imbalance in a motor, according to yet another exemplary embodiment. Figure 5 This is a flowchart illustrating a current compensation method according to an exemplary embodiment; Figure 6 This is a schematic diagram of the structure of a vehicle-mounted device according to an exemplary embodiment; Figure 7 This is a schematic diagram of the structure of a device for processing three-phase current imbalance in a motor, according to an exemplary embodiment. Figure 8 This is a schematic diagram of the structure of an in-vehicle device according to another exemplary embodiment. Detailed Implementation

[0052] The embodiments of this disclosure will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of this disclosure from the content disclosed in this specification. This disclosure can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this disclosure. It should be understood that the preferred embodiments are only for illustrating this disclosure and not for limiting the scope of protection of this disclosure.

[0053] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this disclosure. Therefore, the drawings only show the components related to this disclosure and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0054] With the rapid development of electric vehicle technology, electric vehicles are being used in more and more households. The motor is the core power source of an electric vehicle; therefore, the motor's operating condition has a significant impact on the comfort of the vehicle during driving. For example, when the three-phase current of the motor is unbalanced, it can cause abnormal vibrations and increased noise within the electric vehicle, affecting the user's driving comfort.

[0055] Before introducing the method for handling the three-phase current imbalance problem of a motor provided in the embodiments of this disclosure, the application scenarios of the method for handling the three-phase current imbalance problem of a motor will be introduced first: For permanent magnet synchronous motors, the vibration is mainly caused by the interaction of stator and rotor harmonic magnetic fields, and the stator winding magnetic field force wave harmonic order... Harmonic order of rotor magnetic field force wave As shown in formulas (1) and (2) below: (1); in, The value can be ±1, ±2, ±3, etc. This represents the number of pole pairs of the motor. (2); in, The value can be 1, 2, 3, etc.

[0056] In some embodiments, the radial electromagnetic force wave generated by the interaction of the stator harmonic magnetic field and the rotor harmonic magnetic field... It can be calculated using the following formulas (3) and / or (4): (3); (4); in, , All are 0, 1, 2, etc.

[0057] Since the amount of stator deformation is inversely proportional to the fourth power of the order of the radial excitation force, the lower the order of the spatial force wave, the greater the stator deformation, leading to increased noise and vibration in the motor. Therefore, in integer-slot permanent magnet synchronous motors, the motor noise reaches its maximum value when the spatial order of the radial electromagnetic force wave is 0 or an integer multiple of (2p). This phenomenon is called "2p-order noise," where p is the number of pole pairs in the motor. Taking an 8-pole motor as an example, its pole pair number p=4, corresponding to 2p=8, and its spatial force wave order is 8. This is mainly caused by the fundamental current wave. Poor stator stiffness can potentially cause 8th-order noise. Current solutions mainly focus on improving stator stiffness, such as optimizing the cutting shape of the stator yoke. However, after the motor is installed in a vehicle, detecting three-phase current imbalance caused by mileage attenuation or other reasons requires disassembling the motor and rewiring for inspection, which adds difficulty to problem-solving.

[0058] To address the aforementioned problems, this disclosure provides a method, apparatus, device, vehicle, storage medium, and computer program product for handling three-phase current imbalance in a motor. In practical applications, the method for handling three-phase current imbalance in a motor can be implemented by a device for handling three-phase current imbalance in a motor. Each functional entity within this device can be implemented by a motor control device. This motor control device includes, but is not limited to, on-board equipment in a vehicle, and control devices on other equipment with motors. For example, other equipment with motors includes, but is not limited to, robots, and other production equipment.

[0059] Figure 1 This is a flowchart illustrating a method for handling three-phase current imbalance in a motor according to an exemplary embodiment. In the following text, the on-board equipment will be used as the execution subject, with reference to... Figure 1 The steps shown herein illustrate a method for handling three-phase current imbalance in a motor provided by an embodiment of this disclosure. The method includes: In step S101, in response to the three-phase current imbalance of the motor, the first operating parameters are obtained.

[0060] In some embodiments, the first operating parameters include the imbalance of the three-phase current of the motor and the influence parameters corresponding to at least one phase current of the three-phase current.

[0061] In some embodiments, the motor includes, but is not limited to, permanent magnet synchronous motors (PMSM), induction motors (IM), and other types of motors.

[0062] In some embodiments, the on-board device may acquire first operating parameters according to a preset cycle.

[0063] In some embodiments, the specific value of the preset period can be set as needed, and this disclosure does not limit this.

[0064] In some embodiments, the influencing parameters corresponding to at least one phase current in the three-phase current include, but are not limited to: the influencing parameters of the phase of at least one phase current in the three-phase current, the influencing parameters of the amplitude of at least one phase current in the three-phase current, etc.

[0065] In some embodiments, the timing for the on-board device to acquire the first operating parameter may include during the operation of the device containing the motor.

[0066] In some embodiments, the vehicle-mounted device may obtain first operating parameters based on the Controller Area Network (CAN) bus.

[0067] In step 102, a first compensation current corresponding to the first operating parameter is determined based on the first mapping relationship; wherein, the first mapping relationship includes the mapping relationship between the operating parameter and the compensation current.

[0068] Understandably, the on-board equipment can store a first mapping relationship, which is a mapping relationship between operating parameters and compensation current. Based on this, when the on-board equipment determines that the three-phase current of the motor is unbalanced, it can determine the compensation current corresponding to the first operating parameter of the motor based on the first mapping relationship, and determine the compensation current corresponding to the first operating parameter of the motor as the first compensation current.

[0069] In some embodiments, the first mapping relationship may include, but is not limited to: a first mapping function between operating parameters and compensation current, a first mapping table between operating parameters and compensation current, etc.

[0070] In some embodiments, when the first mapping relationship is a first mapping function, after obtaining the first operating parameters, the vehicle-mounted device can use the first operating parameters as independent variables to calculate the compensation current through the first mapping function, and use the calculated compensation current as the first compensation current.

[0071] In some embodiments, when the first mapping relationship is a first mapping table, after obtaining the first operating parameters, the vehicle-mounted device can look up the compensation current corresponding to the first operating parameters from the first mapping table and use the compensation current corresponding to the first operating parameters as the first compensation current.

[0072] In step 103, the preset current of the motor is compensated based on the first compensation current to obtain the compensated current of the motor.

[0073] Understandably, after receiving the first compensation current, the on-board equipment compensates for the motor's preset current based on this first compensation current. At this point, the on-board equipment can obtain the motor's compensated current.

[0074] In some embodiments, after obtaining the first compensation current, the on-board device can further adjust the first compensation current based on the motor's aging compensation factor α_age to obtain a fourth compensation current. Based on this, the on-board device can compensate the motor's preset current based on the fourth compensation current to obtain the compensated current for the motor.

[0075] In some embodiments, the aging compensation factor of the motor can be determined based on the cumulative running time of the motor and / or the cumulative running time of the vehicle in which the motor is located, in order to solve the three-phase current imbalance caused by motor aging and improve the treatment effect of the three-phase current imbalance of the motor.

[0076] In some embodiments, the magnitude of the aging compensation factor of the motor is positively correlated with the magnitude of the cumulative running time.

[0077] For example, when the vehicle age is less than or equal to 5 years, the motor aging compensation factor can be set to 1; when the vehicle age is greater than 5 years, the motor aging compensation factor can be set to 1.1. When the vehicle mileage is less than or equal to a mileage threshold, the motor aging compensation factor can be set to 1; when the vehicle mileage is greater than a mileage threshold, the motor aging compensation factor can be set to 1.1.

[0078] In some embodiments, the first compensation current may include the first compensation current of the motor's d-axis and the first compensation current of the motor's q-axis, or it may be the compensation current of at least one phase of the motor's three-phase current.

[0079] In some embodiments, when the first compensation current is the first compensation current of the motor d-axis and the first compensation current of the motor q-axis, the on-board device can compensate the preset current (original current) of the d-axis based on the first compensation current of the d-axis to obtain the current after compensation of the d-axis, and compensate the preset current (original current) of the q-axis based on the first compensation current of the q-axis to obtain the current after compensation of the q-axis, wherein the current after compensation of the d-axis and the current after compensation of the q-axis are the current after compensation of the motor.

[0080] In some embodiments, when the first compensation current is the first compensation current of at least one phase of the three-phase current of the motor, the on-board device can first convert the first compensation current of at least one phase of the three-phase current into a first compensation current for the d-axis and / or a first compensation current for the q-axis. Then, the on-board device can compensate a preset current for the d-axis based on the first compensation current for the d-axis to obtain a d-axis compensated current, and / or compensate a preset current for the q-axis based on the first compensation current for the q-axis to obtain a q-axis compensated current.

[0081] In some embodiments, the preset current can be the current used to drive the motor before compensation.

[0082] In step 104, the motor rotation is controlled based on the compensated current.

[0083] Understandably, once the onboard equipment receives the compensated current from the motor, it can control the motor's rotation based on this compensated current.

[0084] In this embodiment, when a motor has a three-phase current imbalance problem, a first compensation current for the motor is determined based on the degree of imbalance of the three-phase current and / or the influence parameters corresponding to at least one phase current. A preset current for the motor is then compensated based on this first compensation current. This can reduce or eliminate the three-phase current imbalance of the motor, thereby reducing or eliminating vibration, noise, and other problems caused by the motor imbalance to the equipment in which it is located.

[0085] In some embodiments, the influencing parameter is a parameter that causes the amplitude and / or phase of at least one phase current to deviate from the equilibrium value, where the equilibrium value is the target amplitude and target phase of at least one phase current when the three phase currents are in balance.

[0086] Understandably, when the three-phase currents of the motor are in a balanced state, each phase current has a target amplitude and a target phase. Based on this, the influence parameter of at least one phase current in the three-phase current can be a parameter that causes the amplitude of at least one phase current in the three-phase current to deviate from the target amplitude, and / or causes the phase of at least one phase current in the three-phase current to deviate from the target phase.

[0087] In some embodiments, the target amplitude and target phase can be preset values.

[0088] In some embodiments, the influencing parameters include the motor operating parameters that cause the amplitude of at least one phase current in the three-phase current to deviate from the target amplitude, and / or cause the phase of at least one phase current in the three-phase current to deviate from the target phase.

[0089] In other embodiments, the influencing parameters include operating parameters of the equipment in which the motor is located that cause the amplitude of at least one phase current of the three-phase current to deviate from the target amplitude, and / or cause the phase of at least one phase current of the three-phase current to deviate from the target phase.

[0090] In some embodiments, the influencing parameters include at least one of the following: motor speed; motor temperature; motor bus voltage fluctuation value; and pedal opening of the vehicle in which the motor is located.

[0091] It should be noted that the motor speed can cause an imbalance in the three-phase current of the motor, for several reasons. Increased motor speed leads to a higher frequency of electromagnetic force waves, making the motor more prone to resonance with other components (i.e., structural modes). Therefore, at high motor speeds, the switching on and off of the inverter is delayed, resulting in a dead-zone effect. This amplifies the current sampling error, leading to motor control deviations and ultimately causing an imbalance in the three-phase current of the motor.

[0092] The reasons why motor temperature can cause imbalance in the three-phase current of a motor include: 1. Increased motor temperature can cause changes in the on-resistance and switching characteristics of power devices, such as Insulated Gate Bipolar Transistors (IGBTs) and Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs), leading to asymmetry in the three-phase current output. 2. The resistance of the motor windings changes with motor temperature, resulting in impedance asymmetry in the three-phase current and also causing imbalance. 3. Motor temperature can affect the zero-point drift of internal components in the controller, such as current sensors and analog-to-digital converters (ADCs), leading to current sampling errors.

[0093] The reasons why fluctuations in the motor's bus voltage cause imbalances in the three-phase current include: Fluctuations in the bus voltage lead to instability, causing distortion in the inverter's output voltage and ultimately resulting in waveform distortion in the three-phase current. Additionally, when the state of charge (SOC) of the battery supplying the motor is low, the bus voltage drops, limiting the current loop bandwidth, leading to decreased control accuracy, and further exacerbating the three-phase current imbalance.

[0094] When the motor is located in a vehicle, the reasons why the motor's three-phase current becomes unbalanced due to the pedal opening of the vehicle include: as the pedal opening increases, the motor torque increases, leading to an increase in the amplitude of the three-phase current and a stronger excitation of the three-phase current imbalance.

[0095] In some embodiments, the imbalance of the three-phase current of the motor is also related to the number of pole pairs of the motor. The number of pole pairs of the motor affects the degree of whistling when the three-phase current is unbalanced. For example, the amplitude and frequency of the 2P-order electromagnetic force wave are different with different pole and slot combinations; the 8th-order whistling is most significant with an 8-pole 48-slot motor, and the 6th-order whistling is most significant with a 6-pole 54-slot motor.

[0096] In some embodiments, the on-board equipment can determine a first compensation current corresponding to the first operating parameters based on one of the following influencing parameters: motor speed, motor temperature, motor bus voltage fluctuation value, pedal opening degree of the vehicle where the motor is located, and the imbalance degree of the motor's three-phase current, through a first mapping relationship. The on-board equipment can determine the first compensation current corresponding to the first operating parameters based on multiple influencing parameters, including motor speed, motor temperature, motor bus voltage fluctuation value, pedal opening degree of the vehicle where the motor is located, and the imbalance degree of the motor's three-phase current, through a first mapping relationship.

[0097] In this embodiment of the disclosure, the first compensation current is determined based on multiple influencing parameters and the imbalance of the three-phase current of the motor, which can improve the accuracy of the determination of the first compensation current.

[0098] In some embodiments, the first mapping relationship includes a first sub-mapping relationship and a second sub-mapping relationship, wherein the first sub-mapping relationship includes a mapping relationship between operating parameters and compensation current gain value, and the second sub-mapping relationship includes a mapping relationship between compensation current gain value and compensation current; step 102 includes: determining a target compensation current gain value corresponding to the first operating parameter based on the first sub-mapping relationship; determining a compensation current corresponding to the target compensation current gain value based on the second sub-mapping relationship; and determining the compensation current corresponding to the target compensation current gain value as the first compensation current.

[0099] Understandably, the first mapping relationship stored in the vehicle-mounted equipment can include a first sub-mapping relationship and a second sub-mapping relationship. The first sub-mapping relationship can be a mapping between operating parameters and compensation current gain values, or a mapping between compensation current gain values ​​and compensation current. Based on this, after obtaining the first operating parameters of the motor, the vehicle-mounted equipment can determine the compensation current gain value corresponding to the first operating parameters based on the first sub-mapping relationship, and determine the compensation current gain value corresponding to the first operating parameters as the target compensation current gain value. After obtaining the target compensation current gain value, the vehicle-mounted equipment can determine the compensation current corresponding to the target compensation current gain value based on the second sub-mapping relationship, and take the compensation current corresponding to the target compensation current gain value as the first compensation current.

[0100] In some embodiments, the first sub-mapping relationship may be a mapping relationship between operating parameters obtained through bench tests or simulation experiments and compensation current gain values.

[0101] In some embodiments, the first sub-mapping relationship may include, but is not limited to: a second mapping function between operating parameters and compensation current gain values, and a second mapping table between operating parameters and compensation current gain values.

[0102] In some embodiments, when the first sub-mapping relationship is a second mapping table, the vehicle-mounted device can look up the compensation current gain value corresponding to the first operating parameter from the second mapping table and use the compensation current gain value corresponding to the first operating parameter as the target compensation current gain value.

[0103] In some embodiments, when the first sub-mapping relationship is the second mapping function, the on-board device can use the first operating parameter as an independent variable to calculate the compensation current gain value through the second mapping function, and use the calculated compensation current gain value as the target compensation current gain value.

[0104] For example, the second mapping function can be shown as formula (5) below: (5); in, To compensate for the current gain value; Functions for offline calibration of multidimensional lookup tables; The unbalance of the three-phase current; This refers to the motor's rotational speed, which can be measured in revolutions per minute (rpm). This refers to the pedal opening, which can be expressed as a percentage (%). This refers to the temperature of the motor, which can be expressed in degrees Celsius (°C). This represents the bus voltage fluctuation value, in volts (V). This represents the number of pole pairs of the motor.

[0105] In some embodiments, the value of the compensation current gain ranges from 0 to 1 (may include two endpoints or may not include two endpoints), and the value of the compensation current gain is positively correlated with the magnitude of the compensation current.

[0106] In some embodiments, the offline calibrated multidimensional lookup table function can be obtained through bench testing or simulation.

[0107] For example, in the process of determining the multidimensional lookup table function based on bench experiments, the motor speed can be fixed. Pedal opening Motor temperature By controlling the operating parameters and gradually injecting unbalanced currents of different amplitudes, the corresponding noise sound pressure levels Lp and Δλ of the motor are recorded, and plotted. With compensation current gain value The relationship curve between them.

[0108] For example, if the motor speed is 3000 rpm, the pedal opening is 50%, and the motor temperature is 60℃, and Δλ is 0.15, then the noise sound pressure level of the motor can only be reduced to the target value when the compensation current gain is 0.7.

[0109] In some embodiments, pedal opening may include accelerator pedal opening.

[0110] In this embodiment of the disclosure, the target compensation current gain value is calculated by the second mapping function, which can be applied to the calculation of the target compensation current gain value of various types of motors (by modifying the number of pole pairs of the motor in Formula 5), ​​thereby solving the three-phase current imbalance problem of various types of motors.

[0111] For example, the method provided in this disclosure can be used to solve the three-phase current imbalance problem of 8-pole 48-slot motors, 6-pole 54-slot motors, 10-pole 60-slot motors, etc.

[0112] In some embodiments, the second sub-mapping relationship may include, but is not limited to: a third mapping function between the compensation current gain value and the compensation current, and a third mapping table between the compensation current gain value and the compensation current.

[0113] In some embodiments, when the second sub-mapping relationship is a third mapping table, the vehicle-mounted device can look up the compensation current corresponding to the target compensation current gain value from the third mapping table and use the compensation current corresponding to the target compensation current gain value as the first compensation current.

[0114] For example, the on-board equipment can also determine the first compensation current using the following formula (6). and : (6); in, For the d-axis of the motor The first compensation current at any given moment; For the q-axis of the motor The first compensation current at any given moment; The compensation direction unit vector (e.g., the negative q-axis direction) is preset or learned online to ensure that the compensation direction of the current is opposite to the unbalanced excitation.

[0115] In some embodiments, when the second sub-mapping relationship is the third mapping function, the vehicle-mounted device can also use the target compensation current gain value as the independent variable, calculate the compensation current through the third mapping function, and use the calculated compensation current as the first compensation current.

[0116] In this embodiment of the disclosure, by pre-storing the first sub-mapping relationship and the second sub-mapping relationship, and after obtaining the first operating parameters, determining the first compensation current through the first sub-mapping relationship and the second sub-mapping relationship, the efficiency of determining the compensation current can be improved, and the computational load of the determination process of the first compensation current can be reduced.

[0117] Furthermore, a first sub-mapping relationship between operating parameters and compensation current gain values ​​is obtained through bench tests or simulation experiments. Therefore, the obtained first sub-mapping relationship more closely approximates the actual operating process of the motor. Based on this, the target compensation current gain value corresponding to the motor's current first operating parameters is determined through the first sub-mapping relationship, and the motor's compensation current is determined based on the target compensation current gain value. This allows the determined compensation current to more closely match the motor's actual needs, thereby improving the effectiveness of solving the motor's three-phase current imbalance problem.

[0118] In some embodiments, the preset current of the motor is compensated based on the first compensation current to obtain the compensated current, including: in response to the first compensation current being the first compensation current of the motor's d-axis and the first compensation current of the motor's q-axis, converting the first compensation current into the compensation current of each phase current in the three-phase current; obtaining the fundamental component from the compensation current of each phase current; determining the second compensation current of the d-axis and the second compensation current of the q-axis based on the fundamental components of the compensation current of the three-phase current; compensating the preset current of the d-axis based on the second compensation current of the d-axis, and compensating the preset current of the q-axis based on the second compensation current of the q-axis to obtain the compensated current.

[0119] Understandably, when the on-board equipment receives the first compensation current as the first compensation current of the motor's d-axis and q-axis, it can convert this first compensation current into the compensation current of each phase of the three-phase current. After obtaining the compensation current of each phase, the on-board equipment can extract the fundamental component from the compensation current of each phase and determine the second compensation current of the motor's d-axis and q-axis based on the fundamental component extracted from the three-phase compensation current. After obtaining the second compensation current of the motor's d-axis and q-axis, the on-board equipment can compensate for the preset current of the d-axis based on the second compensation current of the d-axis, and compensate for the preset current of the q-axis based on the second compensation current of the q-axis. At this point, the compensated current obtained by the on-board equipment can include both the compensated current of the d-axis and the compensated current of the q-axis. Based on this, the on-board equipment can control the motor operation based on the compensated current of the d-axis and the compensated current of the q-axis.

[0120] In some embodiments, the on-board equipment can determine the compensation current of each phase current among the three-phase currents that correspond to both the first compensation current on the d-axis and the first compensation current on the q-axis, based on a third mapping relationship.

[0121] For example, the third mapping relationship may include the fourth mapping function shown in formula (7). Based on this, the on-board equipment can determine the compensation current of each phase current in the three-phase current by using the first compensation current of the d-axis and the first compensation current of the q-axis as independent variables through the fourth mapping function.

[0122] (7); in, For three-phase current Phase current at The compensation current at any given moment; For three-phase current Phase current at The compensation current at any given moment; For three-phase current Phase current at The compensation current at any given moment; It can be calculated using the following formulas (8) and (9).

[0123] (8); in, Let be the electrical angle of the motor rotor, and It can be obtained through the following formula (9): (9); in, It can be obtained through the following formula (10); The initial electrical angle of the motor rotor.

[0124] (10); in, This represents the number of pole pairs of the motor. This refers to the mechanical angular velocity.

[0125] In some embodiments, the electrical angle of the motor rotor can be obtained from the real-time output of the motor encoder or the field-oriented control (FOC) algorithm.

[0126] In some embodiments, the on-board equipment can extract the fundamental component from the compensation current of each phase current based on a recursive algorithm.

[0127] In some embodiments, the recursive algorithms used by the in-vehicle device include, but are not limited to: Sliding Discrete Fourier Transform (SDFT) algorithm, Fast Fourier Transform (FFT) algorithm, Recursive Hopping Discrete Fourier Transform (RHDFT) algorithm, Modulated Sliding Discrete Fourier Transform (MSDFT) algorithm, etc.

[0128] For example, the formula for extracting the fundamental component from the compensation current of each phase current in the three-phase current based on the SDFT algorithm of the on-board equipment can be shown in the following formula (11): (11); in, The first of the three-phase currents The fundamental component of the phase current compensation current, where, The values ​​are as follows: ; The length of the sliding window. Sampling frequency, The fundamental frequency; The sampling period.

[0129] In some embodiments, the fundamental frequency can be the electrical frequency of the motor.

[0130] In some embodiments, the sampling frequency can be set as needed, for example, 10 kHz.

[0131] In some embodiments, after obtaining the fundamental component of each phase current, the on-board equipment can determine the fundamental compensation current of each phase current based on the fundamental component extracted from the compensation current of each phase current. Then, the on-board equipment can determine the second compensation current along the d-axis and the second compensation current along the q-axis based on the fundamental compensation currents of the three-phase currents.

[0132] In some embodiments, the on-board device may use the fundamental component extracted from the compensation current of each phase current as the independent variable to calculate the fundamental compensation current of each phase current through a fifth mapping function.

[0133] For example, the fifth mapping function can be expressed by the following formula (12): (12); in, The first of the three-phase currents The fundamental compensation current of the phase current, The values ​​are as follows: .

[0134] In some embodiments, the on-board equipment can determine the second compensation current of the d-axis and the second compensation current of the q-axis based on the fundamental compensation current of the three-phase current using the following formula (13): (13); in, This is the second compensation current along the d-axis; This is the second compensation current along the q-axis; for The fundamental compensation current of the phase current; for The fundamental compensation current of the phase current; for The fundamental compensation current of the phase current.

[0135] In some embodiments, the vehicle-mounted device can use the following formula (14) to compensate the preset current of the d-axis based on the second compensation current of the d-axis to obtain the current after compensation of the d-axis, and use the following formula (15) to compensate the preset current of the q-axis based on the second compensation current of the q-axis to obtain the current after compensation of the q-axis.

[0136] (14); in, This is the current after d-axis compensation; This is the preset current for the d-axis.

[0137] (15); in, This is the current after q-axis compensation; This is the preset current for the q-axis.

[0138] In some embodiments, after obtaining the compensated current from the motor, the on-board equipment can input the current value of the compensated current into the motor controller, so that the controller can generate a switching signal to drive the inverter of the motor.

[0139] In some embodiments, inputting the compensated current value into the motor controller may include: inputting the compensated current value into a space vector modulation (SVM) module or inputting the compensated current value into a hysteresis modulator.

[0140] In some embodiments, after receiving the second compensation current, the electronic device may also adjust the second compensation current based on the aging compensation factor to obtain the fifth compensation current, and compensate the preset current of the motor based on the fifth compensation current.

[0141] It should be noted that the method by which the on-board equipment adjusts the second compensation current based on the aging compensation factor can be referenced to the method by which the on-board equipment compensates the first compensation current based on the aging compensation factor. Furthermore, the method by which the on-board equipment compensates the preset current of the motor based on the fourth or fifth compensation current can be referenced to the method by which the preset current of the motor is compensated based on the second compensation current; these details will not be elaborated further in this disclosure.

[0142] In this embodiment of the present disclosure, the on-board equipment obtains the fundamental component from the compensation current of each phase current, and determines the second compensation current on the d-axis and the second compensation current on the q-axis based on the fundamental components of the compensation current of the three-phase current. Thus, the obtained second compensation current is the fundamental compensation current, which can reduce the impact of compensation currents with higher harmonics being superimposed on the preset current.

[0143] In some embodiments, the method further includes: acquiring the force wave amplitude of the motor; determining a first gain coefficient corresponding to the three-phase current of the motor based on the force wave amplitude and a first response signal corresponding to the force wave amplitude; wherein the first response signal value includes noise value and / or vibration acceleration value caused by the imbalance of the three-phase current of the motor before current compensation is performed on the motor; determining the degree of imbalance of the three-phase current based on the difference between the first gain coefficient and the second gain coefficient, wherein the second gain coefficient is the gain coefficient corresponding to the three-phase current of the motor in a balanced state.

[0144] Understandably, a motor will generate a first response signal when the three-phase current is unbalanced. Based on this, the on-board equipment can acquire the force wave amplitude of the motor and, based on the force wave amplitude and the first response signal value used to characterize the magnitude of the first response signal, determine the first gain coefficient corresponding to the three-phase current of the motor. After obtaining the first gain coefficient corresponding to the three-phase current of the motor, the on-board equipment can determine the difference between the first gain coefficient and the second gain coefficient, and, based on the difference between the first gain coefficient and the second gain coefficient, determine the degree of imbalance of the three-phase current. The second gain coefficient is the gain coefficient corresponding to the three-phase current when the motor's three-phase current is in a balanced state.

[0145] In some embodiments, the on-board device can determine the electromagnetic force wave of the motor based on the d-axis current and q-axis current of the motor using an electromagnetic force wave model. Then, the on-board device can perform a Fourier transform on the electromagnetic force wave of the motor to obtain its spectrum, and extract the amplitude of a preset frequency from the spectrum to obtain the force wave amplitude of the motor.

[0146] For example, when the number of pole pairs of the motor is 2, the electromagnetic force wave model can be a 2P-order electromagnetic force wave model constructed based on the electromagnetic principles of the motor, with the current on the d-axis and the current on the q-axis as independent variables.

[0147] In some embodiments, when the number of pole pairs of the motor is 2, the force wave amplitude determined based on the 2P-order electromagnetic force wave model is the theoretical 2P-order force wave amplitude.

[0148] For example, the electromagnetic force wave model can be shown in the following formula (16): (16); in, This is the instantaneous expression for electromagnetic force waves; It is the electromagnetic force coefficient; This represents the current along the d-axis of the motor. This is the q-axis current of the motor; The rotor electrical angle is given.

[0149] In some embodiments, the current of the motor's d-axis and q-axis can be obtained via the CAN bus.

[0150] In some embodiments, the electromagnetic force coefficient is related to the structural parameters of the motor and can be obtained through the structural parameters of the motor or bench calibration.

[0151] In some embodiments, the structural parameters of the motor include, but are not limited to, air gap, pole arc, winding distribution, etc.

[0152] In some embodiments, The included frequency is The component, that is, the 2P-order electromagnetic force wave.

[0153] In some embodiments, the preset frequency can be determined by the following formula (17): (17); in, Preset frequency; This is the mechanical frequency of the motor.

[0154] In some embodiments, the on-board equipment can determine the force wave amplitude of the motor using the following formula (18): (18); The amplitude of the force wave.

[0155] In some embodiments, noise values ​​include, but are not limited to, noise sound pressure level and noise amplitude.

[0156] In some embodiments, the in-vehicle device can acquire audio signals based on in-vehicle audio acquisition devices, and extract 2P-order noise values ​​synchronized with motor speed through order tracking analysis. At this point, the onboard equipment can obtain the 2P-order noise value. As the first response signal value.

[0157] For example, the audio acquisition device located in the vehicle may include, but is not limited to, an in-vehicle microphone. For instance, the in-vehicle device may acquire audio signals based on a microphone located at the driver's right ear (approximately 5 cm from the ear canal), wherein the microphone's sensitivity may be -38 dBV / Pa, its frequency response may be 20 Hz–20 kHz, and its sampling rate may be set to 25600 Hz.

[0158] In some embodiments, the on-board equipment can also acquire the vehicle body's acceleration signal and extract the 2P-order vibration acceleration value synchronized with the motor speed through order tracking analysis slices. At this point, the onboard equipment can obtain the 2P-order vibration acceleration value. As the first response signal value.

[0159] In some embodiments, the vibration acceleration value includes, but is not limited to, the vibration acceleration amplitude and the effective value of the vibration acceleration.

[0160] In some embodiments, the in-vehicle device may also prioritize collecting noise values ​​based on the microphone, and then collect vibration acceleration values ​​of the vehicle body when there is no microphone in the vehicle.

[0161] In some embodiments, the first response signal value corresponding to the force wave amplitude may include a first response signal value whose difference between the acquisition time of the d-axis current and the q-axis current used to calculate the force wave amplitude is less than a difference threshold.

[0162] In some embodiments, after obtaining the force wave amplitude and the first response signal value, the vehicle-mounted device can determine a first gain coefficient corresponding to both the force wave amplitude and the first response signal value based on a fifth mapping relationship, wherein the fifth mapping relationship is the mapping relationship between the force wave amplitude and the response signal value and the gain coefficient.

[0163] In some embodiments, the on-board equipment can determine the three-phase current imbalance of the motor using the following formula (19): (19); in, The imbalance of the three-phase current of the motor; The first gain coefficient; This is the second gain coefficient.

[0164] In some embodiments, the greater the difference between the first gain coefficient and the second gain coefficient, the greater the imbalance of the three-phase current of the motor.

[0165] In some embodiments, the second gain coefficient can be a reference gain coefficient when the motor is in an ideal three-phase current balance state.

[0166] In this embodiment, when the motor has a three-phase current imbalance, an additional negative-sequence magnetic field excitation is introduced at the 2P-order frequency, causing an abnormal increase in the actual first response signal value, which in turn leads to an increase in the difference between the first gain coefficient and the second gain coefficient. Therefore, based on the first response signal value and the force wave amplitude of the motor, the first gain coefficient corresponding to the three-phase current of the motor in an unbalanced state can be determined. Thus, the difference between the first gain coefficient and the second gain coefficient can accurately reflect the degree of imbalance of the three-phase current of the motor.

[0167] In some embodiments, determining a first gain coefficient corresponding to the three-phase current of the motor based on the force wave amplitude and a first response signal corresponding to the force wave amplitude includes: determining a candidate gain coefficient based on the force wave amplitude using a recursive least squares method and / or a recurrent neural network; determining a second response signal value based on the candidate gain coefficient and the force wave amplitude using a second mapping relationship; the second mapping relationship is a mapping relationship between the gain coefficient and the force wave amplitude and the response signal value; and determining the candidate gain coefficient as the first gain coefficient if the difference between the second response signal value and the first response signal value is less than or equal to a difference threshold.

[0168] Understandably, the on-board equipment can store a second mapping relationship between the gain coefficient and the force wave amplitude and the response signal value. Based on this, after obtaining the force wave amplitude of the motor, the on-board equipment can calculate a gain coefficient using recursive least squares and / or a recurrent neural network, and use this gain coefficient as a candidate gain coefficient. After obtaining the candidate gain coefficient, the on-board equipment can determine the second response signal value based on the candidate gain coefficient and the force wave amplitude through the second mapping relationship. Then, the on-board equipment can calculate the difference between the second response signal value and the first response signal value, and if the difference is less than or equal to a difference threshold, use the candidate gain coefficient as the first gain coefficient.

[0169] In some embodiments, if the difference between the second response signal value and the first response signal value is greater than a difference threshold, the on-board device can reacquire the force wave amplitude and recalculate the second response signal value.

[0170] In some embodiments, the second mapping relationship may include a fourth mapping table, a sixth mapping function, etc.

[0171] In some embodiments, when the second mapping relationship is a fourth mapping table, the vehicle-mounted device can look up the gain coefficient corresponding to both the force wave amplitude and the response signal value from the fourth mapping table, and use the obtained gain coefficient as the first gain coefficient.

[0172] In some embodiments, when the second mapping relationship is the sixth mapping function, the vehicle-mounted device can determine the first gain coefficient by using the force wave amplitude and response signal value of the motor as independent variables through the sixth mapping function.

[0173] For example, the sixth mapping function can be represented by the following formula (20): (20); in, For response signal value; The gain coefficient reflects the transmission efficiency from theoretical electromagnetic excitation to measured response. This represents the model residuals.

[0174] In some embodiments, the noise response residual can be calculated using formula (20).

[0175] In some embodiments, model residuals include, but are not limited to, measurement noise, structural nonlinearity, and environmental disturbances.

[0176] In some embodiments, the gain coefficient is learned and updated in real time through online recursive least squares (RLS) or a lightweight recurrent neural network (RNN) to ensure that it dynamically adapts to motor aging and changes in operating conditions.

[0177] In this embodiment of the disclosure, if the difference between the second response signal and the first response signal is less than or equal to a difference threshold, it indicates that the currently calculated candidate gain coefficient is the same as or similar to the actual gain coefficient caused by the first response signal value. In this case, using the candidate gain coefficient as the first gain coefficient to determine the imbalance of the three-phase current of the motor can further improve the accuracy of determining the imbalance of the three-phase current.

[0178] In some embodiments, obtaining the force wave amplitude of the motor includes: determining the current operating condition of the motor based on a second operating parameter of the motor; and obtaining the force wave amplitude of the motor in response to the current operating condition being a preset operating condition.

[0179] Understandably, before determining the imbalance of the three-phase current, the on-board equipment can first determine the current operating condition of the motor based on the motor's second operating parameters. These second operating parameters include at least one operating parameter that differs from the first operating parameter. If the on-board equipment determines that the motor's current operating condition is a preset condition, it can further obtain the motor's force wave amplitude.

[0180] In some embodiments, if the current operating condition of the motor is not the preset operating condition, the on-board equipment does not need to obtain the force wave amplitude of the motor.

[0181] In some embodiments, the preset operating condition can be an operating condition that is likely to cause three-phase current imbalance in the motor.

[0182] In some embodiments, the second operating parameters include, but are not limited to, the motor torque, the bus voltage, and the motor speed.

[0183] For example, the preset operating conditions include, but are not limited to, at least one of the following: high load operating conditions, weak magnetic field operating conditions, and high speed operating conditions.

[0184] In some embodiments, when the motor torque is greater than or equal to a torque threshold, the on-board equipment can determine that the current operating condition of the motor is a high-load condition.

[0185] In some embodiments, the torque threshold can be set as needed.

[0186] In some embodiments, the torque threshold may be determined based on the maximum torque of the motor.

[0187] For example, the torque threshold can be a first preset percentage of the motor's maximum torque, wherein the specific value of the first preset percentage can be set as needed, such as 40%, 50%, 60%, etc.

[0188] For example, for a 100 kW motor, since the maximum torque of a 100 kW motor is 156 Nm... Therefore, the torque threshold for a 100kW motor can be 78Nm. For a 180kW motor, since the maximum torque of a 180kW motor is 230Nm, the torque threshold for a 180kW motor can be 115Nm.

[0189] In some embodiments, when the bus voltage of the motor is less than or equal to a voltage threshold and the current of the q-axis is greater than or equal to a current threshold, the current operating condition of the motor is determined to be a field weakening condition.

[0190] In some embodiments, both the voltage threshold and the current threshold can be set as needed.

[0191] For example, the voltage threshold value may include, but is not limited to, 300V, 400V, 500V, etc.

[0192] For example, the current threshold can be a second preset percentage of the rated current of the q-axis, and the value of the second preset percentage can also be set as needed. For example, the value of the second preset percentage can be 70%, 80%, 90%, etc.

[0193] In some embodiments, when the motor speed is within a preset speed range where whistling is likely to occur, the current operating condition of the motor is determined to be a high-speed operating condition.

[0194] In this embodiment of the disclosure, when the current operating condition of the motor is a preset operating condition that is prone to causing three-phase current imbalance, the amplitude of the force wave of the motor is obtained, the degree of imbalance of the three-phase current of the motor is determined based on the obtained amplitude of the force wave, and the first compensation current is determined based on the degree of imbalance of the three-phase current of the motor to apply to the preset current of the motor, so as to realize the timely detection and timely resolution of the three-phase current imbalance problem of the motor.

[0195] In some embodiments, in response to the current operating condition of the motor being a preset operating condition, the force wave amplitude of the motor is obtained, including: in response to the current operating condition being a preset operating condition, determining the operating state of the motor; and in response to the motor being in a stable operating state, obtaining the force wave amplitude of the motor.

[0196] Understandably, once the onboard equipment determines that the motor's current operating condition is within the preset range, it can further determine the motor's current operating status. If the motor is currently operating stably, the onboard equipment can further acquire the motor's force wave amplitude.

[0197] In some embodiments, the motor is determined to be in a stable operating state if the motor meets at least one of the following conditions: the fluctuation range of the motor speed within a preset time period is less than or equal to a second amplitude threshold; the fluctuation range of the motor torque within a preset time period is less than or equal to a third amplitude threshold.

[0198] In some embodiments, the values ​​of the second amplitude threshold and the third amplitude threshold can be set as needed.

[0199] For example, the size of the second amplitude threshold may include, but is not limited to, 15 rpm, 20 rpm, 25 rpm, etc.

[0200] For example, the magnitude of the third amplitude threshold can be a third preset percentage of the rated torque of the motor, wherein the magnitude of the third preset percentage can be set as needed. For example, the third preset percentage can include, but is not limited to, 2%, 3%, 4%, 5%, etc.

[0201] In some embodiments, the specific value of the preset duration can also be set as needed. For example, the preset duration can be greater than or equal to 100 milliseconds (ms). For instance, the preset duration can include any duration between 100ms and 500ms.

[0202] In this embodiment of the disclosure, after determining that the motor is in a stable operating state, the vehicle-mounted equipment further obtains the force wave amplitude of the motor, which can improve the accuracy of the obtained force wave amplitude, and thus improve the accuracy of the unbalance of the three-phase current determined based on the force wave amplitude.

[0203] In some embodiments, the method further includes: after controlling the motor to operate based on the compensated current, acquiring a third response signal value of the motor; wherein the third response signal value includes a noise value and / or vibration acceleration value caused by the three-phase current imbalance of the motor; in response to the third response signal value decreasing by a magnitude greater than or equal to a first response signal value, continuing to compensate the preset current of the motor based on a first compensation current; the first response signal value includes a noise value and / or vibration acceleration value caused by the three-phase current imbalance of the motor before current compensation is performed on the motor; in response to the third response signal value decreasing by a magnitude less than the first response signal value, adjusting the determination method of the first compensation current, redetermining the first compensation current based on the adjusted determination method, and compensating the preset current of the motor based on the redetermined first compensation current.

[0204] Understandably, after controlling the motor's operation based on the compensated current, the on-board equipment can obtain the motor's third response signal value. The type of the third response signal value is the same as the first response signal value; for example, if the first response signal value is noise, the third response signal value is also noise; if the first response signal value is vibration acceleration, the third response signal value is also vibration acceleration. After obtaining the third response signal value, the on-board equipment can calculate the reduction magnitude of the third response signal value relative to the first response signal value. If the reduction magnitude of the third response signal value relative to the first response signal value is greater than or equal to a first magnitude threshold, then compensation for the motor's preset current continues based on the first compensation current. If the reduction magnitude of the third response signal value relative to the first response signal value is less than the first magnitude threshold, the on-board equipment can adjust the determination method of the first compensation current and redetermine the first compensation current based on the adjusted method. After obtaining the redetermined first compensation current, the on-board equipment can compensate for the motor's preset current based on the redetermined compensation current.

[0205] In some embodiments, when the response signal value is a noise value, the on-board device can calculate the residual between the noise value in the third response signal value and the noise value in the first response signal value. If the residual is greater than or equal to a first amplitude threshold, the on-board device can continue to compensate the preset current of the motor based on the first compensation current. If the residual is less than the first amplitude threshold, the on-board device can adjust the determination method of the first compensation current, redetermine the first compensation current based on the adjusted determination method, and compensate the preset current of the motor based on the redetermined first compensation current.

[0206] In some embodiments, the magnitude of the first amplitude threshold can be set as needed.

[0207] For example, the size of the first amplitude threshold can be 25%, 30%, 35%, etc.

[0208] In some embodiments, after the on-board equipment receives the redefined first compensation current, it can calculate a new second compensation current based on the redefined first compensation current and compensate the preset current of the motor based on the new second compensation current.

[0209] In this embodiment, after the on-board device controls the motor to run based on the compensated current, it can also acquire a third response signal value and calculate the reduction magnitude of the third response signal value relative to the first response signal value. This reduction magnitude characterizes the compensation effect of the first compensation current on the imbalance of the motor's three-phase current. If the reduction magnitude of the third response signal value relative to the first response signal value is greater than or equal to a first magnitude threshold, it indicates that the motor's operation effect after compensation based on the first compensation current has achieved the expected effect. If the reduction magnitude of the third response signal value relative to the first response signal value is less than the first magnitude threshold, it indicates that the current current compensation strategy may not be suitable. In this case, the compensation strategy is adjusted, that is, the method of determining the first compensation current is adjusted. In this way, the efficiency of obtaining a suitable first compensation current can be improved, thereby improving the solution effect of the motor's three-phase current imbalance problem.

[0210] In some embodiments, the first operating parameter is obtained according to a preset period; in response to the decrease of the third response signal value relative to the first response signal value being less than a first amplitude threshold, the determination method of the first compensation current is adjusted, and the first compensation current is re-determined based on the adjusted determination method, including obtaining the number of invalid compensations of the preset current in response to the decrease of the third response signal value relative to the first response signal value being less than the first amplitude threshold, wherein the number of invalid compensations is the number of times the decrease of the third response signal value relative to the first response signal value is less than the first amplitude threshold when the preset current is compensated and the motor is run based on the compensated current; in response to the number of invalid compensations being less than or equal to the number threshold, the preset period is adjusted, and the first compensation current is re-determined based on the first operating parameter obtained according to the adjusted preset period; in response to the number of invalid compensations being greater than the number of invalid compensations, the obtained first compensation current is attenuated.

[0211] Understandably, when the vehicle-mounted device determines that the decrease in the third response signal value relative to the first response signal value is less than a first amplitude threshold, it can obtain the number of invalid compensations performed on the preset current of the motor based on the first compensation current. The invalid compensation count is the number of consecutive occurrences where, after compensating the preset current of the motor with the first compensation current and operating the current, the decrease in the third response signal value relative to the first response signal value is less than the first amplitude threshold; that is, the number of iterations is determined. If the number of invalid compensations is less than or equal to the threshold, the vehicle-mounted device can adjust the preset period for acquiring the first operating parameters, acquire the first operating parameters based on the adjusted preset period, and redetermine the first compensation current based on the acquired first operating parameters. Then, it compensates the preset current of the motor based on the redetermined first compensation current. If the number of invalid compensations exceeds the threshold, the vehicle-mounted device can attenuate the obtained first compensation current after obtaining it and use the attenuated first compensation current as the redetermined first compensation current. In this case, the vehicle-mounted device can compensate the preset current of the motor based on the attenuated first compensation current.

[0212] In some embodiments, the threshold value can be set as needed.

[0213] For example, the threshold value can include 3 times, 4 times, 5 times, etc.

[0214] In some embodiments, the on-board device can adjust the preset cycle according to a preset step size.

[0215] In some embodiments, the specific value of the preset step size can be set as needed.

[0216] For example, the preset step size may include, but is not limited to, 5%, 10%, 15%, etc.

[0217] In some embodiments, adjusting the preset period includes shortening the preset period.

[0218] In some embodiments, the on-board equipment may attenuate the first compensation current according to a preset attenuation range.

[0219] In some embodiments, the preset attenuation level can be set as needed.

[0220] For example, the preset attenuation range may include: 10%, 15%, 20%, 25%, 30%, etc.

[0221] In some embodiments, the attenuated first compensation current can be the latest first compensation current obtained by the on-board equipment.

[0222] In this embodiment, if the number of times the on-board device performs ineffective compensation on the preset current of the motor based on the first compensation current exceeds a threshold, the obtained first compensation current is attenuated, and the preset current of the motor is compensated based on the attenuated first compensation current. This reduces the probability of motor instability caused by overcompensation of the preset current.

[0223] In some embodiments, the method further includes: outputting a prompt message, wherein the prompt message is used to indicate possible causes of the three-phase current imbalance.

[0224] In some embodiments, if the on-board equipment determines that the number of invalid compensations exceeds a threshold, it may also output a prompt message, wherein the prompt message is used to indicate the possible hardware cause of the three-phase current imbalance in the motor.

[0225] For example, the prompts may include, but are not limited to: suggestions to check stator stiffness, and the possibility of zero-point drift in the current sensor.

[0226] In some embodiments, the on-board device may also store the acquired first operating parameters, which are used for subsequent calibration iterations and model optimization.

[0227] In this embodiment of the disclosure, not all causes of three-phase current imbalance in the motor can be alleviated or resolved by the first compensation current. Therefore, if the three-phase current imbalance problem in the motor cannot be resolved or alleviated by repeatedly executing the methods provided in this embodiment of the disclosure, a prompt message can be output to indicate the possible causes of the three-phase current imbalance problem in the motor, which can help maintenance personnel quickly find the cause of the fault.

[0228] In some embodiments, step 102 includes: in response to a three-phase current imbalance of the motor, and the degree of imbalance of the three-phase current is greater than the degree of imbalance threshold, determining a first compensation current corresponding to the first operating parameter based on a first mapping relationship.

[0229] Understandably, the on-board equipment can periodically acquire the unbalance of the three-phase current and determine the relationship between the unbalance of the three-phase current and the unbalance threshold, that is, compare the unbalance of the three-phase current with the unbalance threshold. If the unbalance of the three-phase current is greater than the unbalance threshold, the first compensation current corresponding to the first operating parameter can be determined based on the first mapping relationship.

[0230] In some embodiments, if the unbalance of the three-phase current of the motor is less than or equal to the unbalance threshold, the three-phase current of the motor can be determined to be balanced.

[0231] In some embodiments, the on-board equipment may determine an imbalance threshold based on the operating conditions of the motor.

[0232] For example, the on-board device can determine the unbalance threshold based on the motor speed, and the magnitude of the unbalance threshold is positively correlated with the magnitude of the motor speed.

[0233] For example, when the motor speed is low, the imbalance threshold can be set to 0.05; when the motor speed is medium, the imbalance threshold can be set to 0.1; and when the motor speed is high, the imbalance threshold can be set to 0.15. Specifically, the motor speed is defined as low when it falls within a first speed range; medium when it falls within a second speed range; and high when it falls within a third speed range. The lower limit of the third speed range is greater than the upper limit of the second speed range, and the lower limit of the second speed range is greater than the upper limit of the first speed range.

[0234] In some embodiments, the specific value ranges of the first speed range, the second speed range, and the third speed range can be set as needed.

[0235] In some embodiments, the on-board equipment may also determine the imbalance threshold based on the motor temperature and whether the motor is in a weak magnetic field condition.

[0236] For example, if the motor temperature exceeds a temperature threshold, the on-board device can also set an imbalance threshold based on the motor temperature. For instance, if the motor temperature exceeds 80°C, the on-board device can set the imbalance threshold to 0.12.

[0237] For example, when the motor is in a weak magnetic field condition, the on-board equipment can set the imbalance threshold to 0.2.

[0238] For example, the on-board equipment can determine the unbalance threshold based on the vehicle speed of the vehicle where the motor is located, and the magnitude of the unbalance threshold is positively correlated with the magnitude of the vehicle speed.

[0239] For example, when the vehicle speed is low, the imbalance threshold can be set to 0.05; when the vehicle speed is medium, the imbalance threshold can be set to 0.1; and when the vehicle speed is high, the imbalance threshold can be set to 0.15. Specifically, a vehicle speed within a first speed range is defined as low; a vehicle speed within a second speed range is defined as medium; and a vehicle speed within a third speed range is defined as high. The lower limit of the third speed range is greater than the upper limit of the second speed range, and the lower limit of the second speed range is greater than the upper limit of the first speed range.

[0240] In some embodiments, the on-board equipment may also determine an imbalance threshold based on the load condition of the device containing the motor. The magnitude of the imbalance threshold is positively correlated with the load on the device containing the motor.

[0241] For example, when the load on the equipment containing the motor (e.g., a vehicle) is light, the imbalance threshold can be set to 0.05; when the load on the equipment containing the motor is medium, the imbalance threshold can be set to 0.1; and when the load on the equipment containing the motor is heavy, the imbalance threshold can be set to 0.15. Specifically, if the load weight of the equipment containing the motor is within a first weight range, the load is determined to be light; if the load weight of the equipment containing the motor is within a second weight range, the load is determined to be medium; and if the load weight of the equipment containing the motor is within a third weight range, the load is determined to be heavy. The lower limit of the third weight range is greater than the upper limit of the second weight range, and the lower limit of the second weight range is greater than the upper limit of the first weight range.

[0242] For example, the imbalance threshold determined based on the motor's operating conditions and / or the load condition of the equipment in which the motor is located can be as shown in Table 1 below: Table 1. Correspondence between motor operating conditions and / or load conditions of the equipment containing the motor and unbalance threshold.

[0243] In some embodiments, the imbalance threshold can also be set as needed.

[0244] In some embodiments, the on-board equipment may also adjust the determined unbalance threshold based on the historical operating conditions of the motor and / or the historical operating conditions of the equipment where the motor is located, and determine whether there is a three-phase current imbalance in the motor based on the adjusted unbalance threshold.

[0245] For example, the historical operating information of the motor may include, but is not limited to: the cumulative running time of the motor and the historical fault information of the motor, wherein the historical fault information of the motor may be determined based on historical fault codes.

[0246] For example, the historical operating information of the equipment where the motor is located may include, but is not limited to: the cumulative operating time of the equipment where the motor is located, and the historical fault information of the equipment where the motor is located. The historical fault information of the equipment where the motor is located may also be determined based on historical fault codes.

[0247] For example, in cases where the cumulative operating time of the vehicle containing the motor exceeds 5,000 hours and / or the motor experiences an overcurrent sensor drift fault, the onboard equipment can reduce the determined imbalance threshold.

[0248] For example, if the cumulative running time of the vehicle where the motor is located exceeds 5000 hours and / or the motor experiences an overcurrent sensor drift fault, the unbalance threshold determined by the on-board equipment is 1, then the unbalance threshold can be adjusted to 0.8.

[0249] In this embodiment, the on-board device determines an imbalance threshold based on different operating conditions of the motor and / or the load condition of the equipment where the motor is located, and uses this threshold to determine whether the three-phase current of the motor is unbalanced. Compared with using a single imbalance threshold to determine whether the three-phase current of the motor is unbalanced, this method improves the accuracy of the determination. Furthermore, the on-board device adjusts the determined imbalance threshold based on the historical operating conditions of the motor and / or the equipment where the motor is located, and uses the adjusted threshold to determine whether the motor has a three-phase current imbalance. This allows for early warning of three-phase current imbalance caused by motor aging.

[0250] In some embodiments, in response to a three-phase current imbalance in the motor, and the degree of imbalance of the three-phase current is greater than an imbalance threshold, determining a first compensation current corresponding to a first operating parameter based on a first mapping relationship includes: in response to a three-phase current imbalance in the motor, and the degree of imbalance of the three-phase current is greater than an imbalance threshold, determining the imbalance range in which the imbalance is located; in response to the imbalance being located within a first imbalance range, determining a first compensation current corresponding to a first operating parameter based on the first mapping relationship, wherein the lower limit of the first imbalance range is greater than the upper limit of a second imbalance range.

[0251] Understandably, if the on-board equipment determines that the imbalance of the three-phase current of the motor is greater than the imbalance threshold, it can further determine the range of imbalance. If the imbalance of the three-phase current is within the first imbalance range, the on-board equipment can determine the first compensation current corresponding to the first operating parameter based on the first mapping relationship.

[0252] In some embodiments, the lower limit of the first imbalance range is greater than the upper limit of the second imbalance range.

[0253] In some embodiments, the upper and lower limits of the first imbalance range and the upper and lower limits of the second imbalance range can be set as needed.

[0254] For example, the upper limit of the first imbalance range can be infinity, and the lower limit is 0.1; the upper limit of the second imbalance range is less than or equal to 0.1, and the lower limit is greater than 0.05.

[0255] In some embodiments, the first imbalance range may include a first sub-imbalance range and a second sub-imbalance range, wherein the lower limit of the first sub-imbalance range is greater than the upper limit of the second imbalance range, and the upper limit of the first sub-imbalance range is less than the lower limit of the second sub-imbalance range.

[0256] For example, the lower limit of the first sub-imbalance range can be greater than 0.1 and the upper limit can be less than or equal to 0.2; the lower limit of the second sub-imbalance range can be greater than 0.2 and the upper limit can be infinity.

[0257] In some embodiments, the on-board equipment may also determine the unbalance level of the three-phase current based on the unbalance range of the three-phase current, and determine the whistling risk level of the motor based on the unbalance level of the three-phase current.

[0258] For example, the on-board equipment can determine the imbalance level and whistling risk level of the three-phase current based on Table 2.

[0259] Table 2. Three-phase current imbalance levels and howling risk levels

[0260] Based on Table 2, when the three-phase current imbalance is within the second imbalance range, the on-board equipment can determine the three-phase current imbalance level as mild and the motor squealing risk level as low; when the three-phase current imbalance is within the first sub-imbalance range, the on-board equipment can determine the three-phase current imbalance level as moderate and the motor squealing risk level as medium; when the three-phase current imbalance is within the second sub-imbalance range, the on-board equipment can determine the three-phase current imbalance level as severe and the motor squealing risk level as high.

[0261] In some embodiments, the on-board device may perform steps 101 to 104 if the motor's squealing risk level is medium or high.

[0262] In some embodiments, the on-board equipment can also store information such as the three-phase current imbalance judgment result, the howling risk level, the trigger time, the motor speed, the motor torque, the motor temperature, the degree of three-phase current imbalance, and the compensation execution record. For example, the information can be stored in the on-board diagnostics (OBD) system of the on-board equipment, so that maintenance personnel of the equipment where the motor is located can locate and repair problems when performing offline testing and maintenance on the equipment where the motor is located.

[0263] In this embodiment, if the imbalance of the three-phase current in the vehicle-mounted equipment is within a first imbalance range, it indicates that the current imbalance of the three-phase current in the motor is quite severe. At this time, the vehicle-mounted equipment determines a first compensation current based on the motor's first operating parameters, compensates the motor's preset current based on the first compensation current, and operates the motor based on the compensated current. This can promptly resolve or alleviate the three-phase current imbalance problem in the motor.

[0264] In addition, when the imbalance of the three-phase current is within the first imbalance range, the first compensation current is determined based on the first operating parameters of the motor, and the preset current of the motor is compensated based on the first compensation current, and the motor is run based on the compensated current. However, when the imbalance of the three-phase current is within the second imbalance range, the preset current of the motor is not compensated. This can also reduce the computational pressure on the on-board equipment caused by determining the first compensation current due to the slight imbalance of the motor's three-phase current.

[0265] Figure 2 This is a schematic flowchart illustrating a method for handling three-phase current imbalance in a motor according to another exemplary embodiment. In the following text, parameters... Figure 2 The steps shown herein illustrate a method for handling three-phase current imbalance in a motor provided in this embodiment. The method includes: In step 201, the second operating parameters of the motor are obtained.

[0266] In step 202, based on the second operating parameters, it is determined whether the current operating condition of the motor is a preset operating condition that is prone to causing three-phase current imbalance. If yes, then step 203 is executed; otherwise, wait for the second operating parameters to be collected again.

[0267] In step 203, the current operating status of the motor is determined.

[0268] In step 204, in response to the motor being in a stable operating state, the force wave amplitude of the motor is calculated.

[0269] In step 205, the first noise signal value of the motor is obtained.

[0270] In step 206, a howling identification model (i.e., the sixth mapping function) is constructed.

[0271] In step 207, the imbalance of the three-phase current is determined by the howling identification model based on the force wave amplitude and the first noise signal value.

[0272] In step 208, it is determined whether the imbalance degree is greater than the imbalance degree threshold. If yes, then step 209 is executed; otherwise, step 203 is executed.

[0273] In step 209, the motor's squealing risk level is determined based on the imbalance of the three-phase current.

[0274] In step 210, if the howling risk level is low, the howling risk level is stored in the OBD.

[0275] In step 211, if the howling risk level is medium or high, a second mapping function is constructed.

[0276] In step 212, the target compensation current gain value of the motor is determined based on the second mapping function.

[0277] In step 213, the first compensation current of the d-axis and the first compensation current of the q-axis are determined based on the target compensation current gain value, and the compensation current of the three-phase current of the motor is determined based on the first compensation current of the d-axis and the first compensation current of the q-axis.

[0278] In step 214, the fundamental component is extracted from the compensation current of the three-phase current.

[0279] In step 215, the second compensation current of the d-axis and the second compensation current of the q-axis are determined based on the fundamental component. The second compensation current of the d-axis is superimposed on the preset current of the d-axis, and the second compensation current of the q-axis is superimposed on the preset current of the q-axis to obtain the motor compensation current.

[0280] In step 216, the residual between the third noise signal value during the motor's operation based on the compensated current and the first noise signal value obtained in step 205 is calculated, and the noise signal value is determined based on the obtained residual to determine whether the noise signal value shows a reduction (e.g., whether the reduction is greater than 30%). If yes, the processing flow ends; otherwise, step 217 is executed.

[0281] In step 217, it is determined whether the number of iterations is greater than the number threshold. If yes, step 218 is executed; otherwise, step 219 is executed.

[0282] In step 218, the first compensation current is attenuated, and the preset current of the motor is compensated based on the attenuated first compensation current.

[0283] In step 219, the preset period is adjusted according to the preset step size, and the first compensation current is re-determined based on the first operating parameters obtained based on the adjusted preset period, and the preset current of the motor is compensated based on the re-determined first compensation current.

[0284] Figure 3 This is a schematic diagram illustrating a comparison of motor noise values ​​before and after current compensation, according to an exemplary embodiment. For example... Figure 3As shown, in a real-vehicle test of a pure electric vehicle driven by an 8-pole 48-slot permanent magnet synchronous motor, significant 2P-order (i.e., 8th-order) howling noise was detected. The measured sound pressure level of the in-vehicle microphone was 56 dB(A), Δλ = 0.22, which was determined to be a high-risk level of howling. The on-board equipment automatically triggered... Figure 6 The compensation control module 604, based on the first operating parameters, looks up the compensation current gain value K=0.8, with the direction being the negative q-axis. It then generates a fundamental compensation current and superimposes it onto the preset current to obtain the compensated current. Within one second of compensating the motor's preset current, the onboard equipment re-collects the noise value (third response signal value). After order tracking analysis, the 8th-order noise amplitude decreases to 10-15 dB(A), Δλ decreases to 0.09, and the risk level decreases from high-risk to low-risk. During the subsequent five minutes of continuous operation, the onboard equipment maintains the current compensation strategy, and the noise stabilizes in the 46-53 dB(A) range.

[0285] Figure 4 This is a flowchart illustrating a method for handling three-phase current imbalance in a motor, according to yet another exemplary embodiment. Figure 5 This is a schematic flowchart illustrating a current compensation method according to an exemplary embodiment. In the following text, reference will be made to... Figure 4 and Figure 5 Taking a vehicle motor as an example, the method provided in this disclosure will be described with several specific embodiments. The method includes: In step 401, the operating parameters of the motor are obtained.

[0286] For example, the vehicle-mounted device can obtain the motor's operating parameters through the vehicle-mounted CAN bus, wherein the motor's operating parameters include a first operating parameter and a second operating parameter.

[0287] For example, the operating parameters of the motor include, but are not limited to: d-axis current, q-axis current, d-axis voltage command, q-axis voltage command, bus voltage value, motor speed, motor torque, vehicle acceleration, vehicle speed, pedal opening and rate of change, and motor temperature. The d-axis voltage command is used for calibrating the d-axis current, and the q-axis voltage command is used for correcting the q-axis current.

[0288] In step 402, it is determined whether the current operating condition of the motor is the preset operating condition.

[0289] For example, when a vehicle enters a high-load condition or a weak magnetic field condition (a region prone to whistling), the motor causes an imbalance in the three-phase current.

[0290] For example, high load determination includes: If the motor torque T is greater than or equal to T_threshold, the three-phase current imbalance diagnosis is triggered. T_threshold is the torque threshold, set based on the motor's maximum torque. For example, for a 100kW motor (maximum torque 156Nm), T_threshold = 78Nm (50% of maximum torque); for a 180kW motor (maximum torque 230Nm), T_threshold = 115Nm (50% of maximum torque).

[0291] For example, the determination of weak magnetic field conditions includes: If the bus voltage Udc is less than or equal to Udc_threshold (e.g., 400V) and the q-axis current iq is greater than or equal to iq_weak (e.g., 80% of the rated current), then the system is considered to have entered the weak magnetic region. Here, Udc_threshold is the voltage threshold and iq_weak is the current threshold.

[0292] In step 403, steady-state condition judgment is performed, that is, the operating stability of the motor is judged. In this process, feature calculation is performed under steady-state conditions to improve diagnostic accuracy.

[0293] The criteria for determining steady-state operating conditions include: the fluctuation range of motor speed is less than or equal to threshold A (20 rpm recommended); the fluctuation range of motor torque is less than or equal to threshold B (3% of rated torque recommended); and the duration is greater than or equal to 100 ms (to ensure data stability). If the criteria for determining steady-state operating conditions are not met, return to step 401 and wait for the operating conditions to stabilize.

[0294] In step 404, the force wave amplitude is calculated.

[0295] For example, within the steady-state time window (e.g., 100ms-500ms), based on the electromagnetic principle of motors, an ideal 2P-order electromagnetic force wave model based on the d-axis current and q-axis current is constructed, wherein the 2P-order electromagnetic force wave model can be as shown in formula (16).

[0296] In step 405, the first response signal value is obtained.

[0297] For example, the first response signal value may include, but is not limited to, the in-vehicle noise amplitude or the vehicle body vibration acceleration amplitude.

[0298] It should be noted that the embodiments disclosed herein do not limit the physical type of the first response signal value; it can be a sound pressure signal or an acceleration signal. Since the structure-acoustic transfer function is approximately constant within the frequency range corresponding to the 2P-order slice, the two signals are equivalent in order tracking analysis and can both be used to construct a linear identification model between electromagnetic excitation and structural response. This design enhances the system's engineering applicability, especially for vehicles without in-vehicle microphones.

[0299] For example, the in-vehicle device synchronously collects audio signals from the in-vehicle microphone, extracts the 2P-order noise value that is synchronized with the motor speed through order tracking analysis, and uses the 2P-order noise value as the first response signal value.

[0300] For example, the vehicle microphone signal uses a microphone located at the driver's right ear (approximately 5 cm from the ear canal); sensitivity: -38 dBV / Pa, frequency response: 20 Hz–20 kHz, and sampling rate set to 25600 Hz.

[0301] For example, if there is no vehicle microphone in the vehicle, the 2P-order vibration acceleration value synchronized with the motor speed can be extracted by analyzing the vehicle body acceleration signal through order tracking, and the 2P-order vibration acceleration value can be used as the first response signal value.

[0302] In step 406, a howling identification model is constructed.

[0303] For example, the howling identification model can be as shown in formula (20).

[0304] In step 407, the generalized electrical imbalance is obtained. That is, the imbalance of the three-phase current.

[0305] In step 408, an imbalance determination is made.

[0306] For example, the generalized electrical imbalance Compare with the imbalance threshold Y_th, if If the current exceeds the threshold Y_th, it is determined that there is an imbalance in the three-phase current, and S409-1 is executed; if If the value is less than or equal to the unbalance threshold Y_th, the three-phase current is determined to be balanced, and step 401 is then executed to monitor the vehicle status.

[0307] In step 409-1, the howling risk level is output.

[0308] For example, according to the generalized electrical imbalance The magnitude of the imbalance is used to classify the levels (mild, moderate, severe) and outputs a corresponding 2p-order electromagnetic howling risk level (low risk, medium risk, high risk). The system adaptively sets the risk level according to the vehicle's low-speed, medium-speed, high-speed, light-load, heavy-load, and weak magnetic field conditions to avoid insufficient detection accuracy under different conditions due to a single threshold. If the howling risk level is medium or high, the on-board equipment automatically triggers the subsequent compensation control module 604 to compensate for the motor's preset current in step 501.

[0309] In step 409-2, OBD is stored.

[0310] For example, information such as imbalance judgment results, howling risk level, trigger time, speed, torque, temperature, Δλ value, and compensation execution records can be stored in the vehicle's OBD system for vehicle manufacturers' off-line inspection personnel and after-sales maintenance personnel to read, facilitating quick problem location and repair.

[0311] It should be noted that the cause of the squealing may be insufficient structural stiffness or component failure, rather than electrical imbalance. The system will automatically output diagnostic prompts (such as "It is recommended to check the stator stiffness or the zero-point drift of the current sensor") and store the abnormal operating condition (including characteristics such as speed, torque, and bus voltage) in the OBD for subsequent calibration iteration and model optimization.

[0312] The steps performed by the compensation control module 604 on the vehicle-mounted equipment include: In step 501, a second mapping function is constructed.

[0313] For example, the vehicle-mounted equipment can construct a second mapping function that can calibrate the compensation intensity based on the physical mechanism of the motor system and engineering measurement experience, through the operating condition characteristics that are strongly related to the current imbalance. The constructed second mapping function is shown in formula (5).

[0314] For example, an aging compensation factor α_age can also be introduced to dynamically adjust the current compensation intensity based on the vehicle's cumulative operating time. For instance, α_age = 1.0 for new vehicles and 1.1 for vehicles after 5 years, using increased current compensation intensity to address aging drift.

[0315] In step 502, the first compensation current of the d-axis and the first compensation current of the q-axis are obtained by looking up the compensation current gain value in a table.

[0316] In step 503, the first compensation current of the d-axis and the first compensation current of the q-axis are subjected to Park inverse transformation to obtain the three-phase instantaneous compensation current.

[0317] In step 504, to avoid high-order harmonic injection, the fundamental component is extracted using a sliding DFT for the compensation current of each phase current.

[0318] In step 505, the fundamental compensation current determined based on the fundamental component is superimposed on the preset current (original current).

[0319] In step 506, after current compensation of the motor, the in-vehicle noise signal is re-acquired, and it is determined whether the noise response residual has decreased significantly (e.g., the noise response residual has decreased by more than 30%). If yes, the current compensation strategy is maintained and the process ends; otherwise, the process proceeds to step 507.

[0320] In step 507, it is determined whether the number of iterations is greater than the number threshold (e.g., 3 times). If not, proceed to step 508; if yes, proceed to step 509.

[0321] In step 508, the preset step size is adjusted (e.g., +10%), and the process returns to step 502 to recalculate the first compensation current for compensation.

[0322] In step 509, if multiple compensations are ineffective (e.g., after 3 iterations, the noise response residual decreases by less than 30%), the system automatically attenuates the compensation amplitude proportionally (e.g., attenuates by 20% each time) to prevent overcompensation from causing instability.

[0323] Figure 6 This is a schematic diagram illustrating the structure of a vehicle-mounted device according to an exemplary embodiment. For example... Figure 6 As shown, the vehicle-mounted device includes a data acquisition module 601, a data processing module 602, an OBD storage module 603, and a compensation control module 604. Step 401 can be executed by the data acquisition module 601, steps 402 to 408-1 can be executed by the data processing module 602, step 408-2 can be executed by the OBD storage module 603, and steps 501 to 509 can be executed by the compensation control module 604.

[0324] Secondly, embodiments of this disclosure provide a device for handling three-phase current imbalance in a motor. Figure 7 This is a schematic diagram illustrating the structure of a device for processing three-phase current imbalance in a motor according to an exemplary embodiment. See also... Figure 7 As shown, the motor three-phase current imbalance processing device 700 may include: a first acquisition module 701, configured to acquire a first operating parameter in response to the motor's three-phase current imbalance; wherein the first operating parameter includes the motor's three-phase current imbalance degree and an influence parameter corresponding to at least one phase current in the three-phase current; a first determination module 702, configured to determine a first compensation current corresponding to the first operating parameter based on a first mapping relationship; wherein the first mapping relationship includes a mapping relationship between the operating parameter and the compensation current; a compensation module 703, configured to compensate a preset current of the motor based on the first compensation current to obtain a compensated current of the motor; and a control module 704, configured to control the motor operation based on the compensated current.

[0325] In some embodiments, the influencing parameter is a parameter that causes the amplitude and / or phase of at least one phase current to deviate from the equilibrium value, where the equilibrium value is the target amplitude and target phase of at least one phase current when the three phase currents are in balance.

[0326] In some embodiments, the influencing parameters include at least one of the following: motor speed; motor temperature; motor bus voltage fluctuation value; and pedal opening of the vehicle in which the motor is located.

[0327] In some embodiments, the first mapping relationship includes a first sub-mapping relationship and a second sub-mapping relationship, wherein the first sub-mapping relationship includes a mapping relationship between operating parameters and compensation current gain value, and the second sub-mapping relationship includes a mapping relationship between compensation current gain value and compensation current; the first determining module 702 is configured to: determine a target compensation current gain value corresponding to the first operating parameters based on the first sub-mapping relationship; determine a compensation current corresponding to the target compensation current gain value based on the second sub-mapping relationship; and determine the compensation current corresponding to the target compensation current gain value as the first compensation current.

[0328] In some embodiments, the compensation module 703 is configured to: in response to the first compensation current being the first compensation current of the motor's d-axis and the first compensation current of the motor's q-axis, convert the first compensation current into the compensation current of each phase of the three-phase current; obtain the fundamental component from the compensation current of each phase current; determine the second compensation current of the d-axis and the second compensation current of the q-axis based on the fundamental components of the compensation current of the three-phase current; compensate the preset current of the d-axis based on the second compensation current of the d-axis, and compensate the preset current of the q-axis based on the second compensation current of the q-axis, to obtain the compensated current.

[0329] In some embodiments, the device further includes: a second acquisition module configured to acquire the force wave amplitude of the motor; a second determination module configured to determine a first gain coefficient corresponding to the three-phase current of the motor based on the force wave amplitude and a first response signal value corresponding to the force wave amplitude; wherein the first response signal value includes noise value and / or vibration acceleration value caused by the three-phase current imbalance of the motor before current compensation is performed on the motor; and a third determination module configured to determine the degree of imbalance of the three-phase current based on the difference between the first gain coefficient and the second gain coefficient, wherein the second gain coefficient is the gain coefficient corresponding to the three-phase current when the motor is in a balanced state.

[0330] In some embodiments, the second determining module is configured to: determine candidate gain coefficients based on the force wave amplitude using a recursive least squares method and / or a recurrent neural network; determine a second response signal value based on the candidate gain coefficients and the force wave amplitude using a second mapping relationship; the second mapping relationship is a mapping relationship between the gain coefficients and the force wave amplitude and the response signal value; and determine the candidate gain coefficients as the first gain coefficients if the difference between the second response signal value and the first response signal value is less than or equal to a difference threshold.

[0331] In some embodiments, the second acquisition module is configured to: determine the current operating condition of the motor based on the second operating parameters of the motor, wherein at least one operating parameter included in the second operating parameters is different from the first operating parameters; and acquire the force wave amplitude of the motor in response to the current operating condition being a preset operating condition.

[0332] In some embodiments, the second acquisition module is configured to: determine the operating state of the motor in response to the current operating condition being a preset operating condition; and acquire the force wave amplitude of the motor in response to the motor being in a stable operating state.

[0333] In some embodiments, the device further includes: a third acquisition module configured to acquire a third response signal value of the motor after the motor is controlled to run based on the compensated current; wherein the third response signal value includes a noise value and / or vibration acceleration value caused by the three-phase current imbalance of the motor; a continued compensation module configured to continue to compensate the preset current of the motor based on the first compensation current in response to the third response signal value decreasing by a magnitude greater than or equal to a first amplitude threshold; the first response signal value includes a noise value and / or vibration acceleration value caused by the three-phase current imbalance of the motor before current compensation is performed on the motor; and an adjustment module configured to adjust the determination method of the first compensation current in response to the third response signal value decreasing by a magnitude less than the first amplitude threshold, and redetermine the first compensation current based on the adjusted determination method, and compensate the preset current of the motor based on the redetermined first compensation current.

[0334] In some embodiments, the first operating parameter is obtained according to a preset period; the adjustment module is configured to: in response to the third response signal value decreasing less than the first response signal value by a factor of less than a first amplitude threshold, obtain the number of invalid compensations of the preset current, wherein the number of invalid compensations is the number of times the decrease of the third response signal value relative to the first response signal value is less than the first amplitude threshold when the preset current is compensated and the motor is operated based on the compensated current; in response to the number of invalid compensations being less than or equal to the number of times threshold, adjust the preset period and redetermine the first compensation current based on the first operating parameter obtained according to the adjusted preset period; in response to the number of invalid compensations being greater than the number of times threshold, attenuate the obtained first compensation current.

[0335] In some embodiments, the device further includes an output module configured to output a prompt message, wherein the prompt message is used to indicate possible causes of three-phase current imbalance.

[0336] In some embodiments, the first determining module 702 is configured to: in response to the three-phase current imbalance of the motor, and the imbalance degree of the three-phase current is greater than the imbalance degree threshold, determine the first compensation current corresponding to the first operating parameter based on the first mapping relationship.

[0337] In some embodiments, the first determining module 702 is configured to: in response to the three-phase current imbalance of the motor and the imbalance degree of the three-phase current is greater than the imbalance degree threshold, determine the imbalance degree range in which the imbalance degree is located; in response to the imbalance degree being within the first imbalance degree range, determine the first compensation current corresponding to the first operating parameter based on the first mapping relationship, wherein the lower limit of the first imbalance degree range is greater than the upper limit of the second imbalance degree range.

[0338] It should be noted that the specific methods by which each module performs its operation in the apparatus described above have been described in detail in the embodiments related to the method, and will not be elaborated upon here. The first determining module 701 may be... Figure 6 The data processing module 602 and the compensation module 702 in the middle can be Figure 6 The compensation control module 604 in the middle.

[0339] Thirdly, this disclosure provides an in-vehicle device. The in-vehicle device includes at least a memory and a processor. The memory stores a computer program that can run on the processor. When the processor executes the computer program, it implements the steps in the method for handling three-phase current imbalance in a motor provided in the above embodiments.

[0340] Thirdly, embodiments of this disclosure provide a vehicle that includes at least onboard equipment and a motor.

[0341] Figure 8 This is a schematic diagram of the structure of a vehicle-mounted device according to another exemplary embodiment, which is described below in conjunction with... Figure 8 The structure of the vehicle-mounted device 800 shown is explained.

[0342] In one example, such as Figure 8 As shown, the vehicle-mounted device 800 includes: a processor 801, at least one communication bus 802, at least one external communication interface 803, and a memory 804. The communication bus 802 is configured to enable communication between these components. The external communication interface 803 may include standard wired and wireless interfaces.

[0343] The memory 804 is configured to store instructions and applications executable by the processor 801, and can also cache data to be processed or already processed by the processor 801 and various modules in the electronic device (e.g., image data, audio data, voice communication data and video communication data), which can be implemented by flash memory or random access memory (RAM).

[0344] In another example, the on-board device can be a vehicle device or a controller. The vehicle device or controller is used to perform the steps in the method for handling three-phase current imbalance in a motor provided in the above embodiments.

[0345] Fourthly, this disclosure also provides a computer-readable storage medium storing executable instructions, wherein when the executable instructions are executed by a processor, they implement the steps in the method for handling three-phase current imbalance in a motor provided in the embodiments of this disclosure.

[0346] Fifthly, this disclosure also provides a computer program product, including a computer program or instructions, which, when executed by a processor, implement the steps in the above-described method for handling the imbalance of three-phase current in a motor.

[0347] It should be noted that the descriptions of the storage medium and device embodiments above are similar to those of the method embodiments above, and have similar beneficial effects. For technical details not disclosed in the storage medium and device embodiments of this disclosure, please refer to the descriptions of the method embodiments of this disclosure for understanding.

[0348] It should be understood that the phrase "one embodiment" or "an embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of this disclosure. Therefore, "in one embodiment" or "in some embodiments" appearing throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that in the various embodiments of this disclosure, the sequence numbers of the above-described processes do not imply a sequential 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 this disclosure. The sequence numbers of the above-described embodiments are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0349] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0350] In the several embodiments provided in this disclosure, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple units or components may be combined, or integrated into another system, or some features may be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the various components shown or discussed may be through some interfaces, and the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0351] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units. They may be located in one place or distributed across multiple network units. Some or all of the units may be selected to achieve the purpose of this embodiment according to actual needs.

[0352] In addition, each functional unit in the various embodiments of this disclosure can be integrated into one processing unit, or each unit can be a separate unit, or two or more units can be integrated into one unit; the integrated unit can be implemented in hardware or in the form of hardware plus software functional units.

[0353] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media that can store program code, such as mobile storage devices, read-only memory (ROM), magnetic disks, or optical disks.

[0354] Alternatively, if the integrated units described above are implemented as software functional modules and sold or used as independent products, they can also be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the embodiments of this disclosure, or the parts that contribute to related technologies, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the motor three-phase current imbalance processing method described in the various embodiments of this disclosure. The aforementioned storage medium includes various media capable of storing program code, such as mobile storage devices, ROMs, magnetic disks, or optical disks.

[0355] The above embodiments are merely preferred embodiments provided to fully illustrate this disclosure, and the scope of protection of this disclosure is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on this disclosure are all within the scope of protection of this disclosure.

Claims

1. A method for handling three-phase current imbalance in a motor, characterized in that, The method includes: In response to the three-phase current imbalance of the motor, a first operating parameter is obtained; wherein, the first operating parameter includes the degree of imbalance of the three-phase current of the motor and the influence parameter corresponding to at least one phase current of the three-phase current; Based on the first mapping relationship, a first compensation current corresponding to the first operating parameter is determined; wherein, the first mapping relationship includes the mapping relationship between the operating parameter and the compensation current; Based on the first compensation current, the preset current of the motor is compensated to obtain the compensated current of the motor; The motor is controlled to operate based on the compensated current.

2. The method according to claim 1, characterized in that, The influencing parameter is a parameter that causes the amplitude and / or phase of the at least one phase current to deviate from the equilibrium value, where the equilibrium value is the target amplitude and target phase of the at least one phase current when the three phase currents are in balance.

3. The method according to claim 1, characterized in that, The influencing parameters include at least one of the following: The speed of the motor; The temperature of the motor; The bus voltage fluctuation value of the motor; The pedal opening of the vehicle where the motor is located.

4. The method according to any one of claims 1 to 3, characterized in that, The first mapping relationship includes a first sub-mapping relationship and a second sub-mapping relationship, wherein the first sub-mapping relationship includes the mapping relationship between the operating parameters and the compensation current gain value, and the second sub-mapping relationship includes the mapping relationship between the compensation current gain value and the compensation current; The step of determining the first compensation current corresponding to the first operating parameter based on the first mapping relationship includes: Based on the first sub-mapping relationship, determine the target compensation current gain value corresponding to the first operating parameter; Based on the second sub-mapping relationship, determine the compensation current corresponding to the target compensation current gain value; The compensation current corresponding to the target compensation current gain value is determined as the first compensation current.

5. The method according to any one of claims 1 to 3, characterized in that, The step of compensating the preset current of the motor based on the first compensation current to obtain the compensated current of the motor includes: In response to the first compensation current being the first compensation current of the d-axis and the first compensation current of the q-axis of the motor, the first compensation current is converted into the compensation current of each phase of the three-phase current. The fundamental component is obtained from the compensation current of each phase current; Based on the fundamental component of the compensation current of the three-phase current, the second compensation current of the d-axis and the second compensation current of the q-axis are determined. The preset current of the d-axis is compensated based on the second compensation current of the d-axis, and the preset current of the q-axis is compensated based on the second compensation current of the q-axis to obtain the compensated current.

6. The method according to any one of claims 1 to 3, characterized in that, The method further includes: Obtain the force wave amplitude of the motor; Based on the force wave amplitude and the first response signal value corresponding to the force wave amplitude, a first gain coefficient corresponding to the three-phase current of the motor is determined; wherein, the first response signal value includes the noise value and / or vibration acceleration value caused by the imbalance of the three-phase current of the motor before current compensation is performed on the motor. The imbalance of the three-phase current is determined based on the difference between the first gain coefficient and the second gain coefficient, wherein the second gain coefficient is the gain coefficient corresponding to the three-phase current when the motor is in a balanced state.

7. The method according to claim 6, characterized in that, The step of determining the first gain coefficient corresponding to the three-phase current of the motor based on the force wave amplitude and the first response signal value corresponding to the force wave amplitude includes: Based on the force wave amplitude, candidate gain coefficients are determined using recursive least squares method and / or recurrent neural network. Based on the candidate gain coefficient and the force wave amplitude, the second response signal value is determined through a second mapping relationship; the second mapping relationship is the mapping relationship between the gain coefficient and the force wave amplitude and the response signal value. If the difference between the second response signal value and the first response signal value is less than or equal to the difference threshold, the candidate gain coefficient is determined as the first gain coefficient.

8. The method according to claim 6, characterized in that, The step of obtaining the force wave amplitude of the motor includes: Based on the second operating parameters of the motor, the current operating condition of the motor is determined, wherein at least one operating parameter included in the second operating parameters is different from the first operating parameters; In response to the current operating condition being a preset operating condition, the force wave amplitude of the motor is obtained.

9. The method according to claim 8, characterized in that, The step of obtaining the force wave amplitude of the motor in response to the current operating condition being a preset operating condition includes: In response to the current operating condition being a preset operating condition, the operating state of the motor is determined; In response to the motor being in a stable operating state, the force wave amplitude of the motor is acquired.

10. The method according to any one of claims 1 to 3, characterized in that, The method further includes: After controlling the motor to operate based on the compensated current, a third response signal value of the motor is obtained; wherein, the third response signal value includes noise value and / or vibration acceleration value caused by the three-phase current imbalance of the motor; In response to the decrease in the value of the third response signal relative to the value of the first response signal being greater than or equal to the first amplitude threshold, the preset current of the motor continues to be compensated based on the first compensation current; the first response signal value includes the noise value and / or vibration acceleration value caused by the three-phase current imbalance of the motor before current compensation is performed on the motor. In response to the fact that the decrease in the value of the third response signal relative to the value of the first response signal is less than the first amplitude threshold, the method for determining the first compensation current is adjusted, and the first compensation current is re-determined based on the adjusted method, and the preset current of the motor is compensated based on the re-determined first compensation current.

11. The method according to claim 10, characterized in that, The first operating parameter is acquired according to a preset cycle; The step of adjusting the determination method of the first compensation current in response to the decrease of the third response signal value relative to the first response signal value being less than the first amplitude threshold, and redetermining the first compensation current based on the adjusted determination method, includes: In response to the fact that the decrease in the third response signal value relative to the first response signal value is less than the first amplitude threshold, the invalid compensation count of the preset current is obtained, wherein the invalid compensation count is the number of times when the preset current is compensated and the motor is run based on the compensated current, the decrease in the third response signal value relative to the first response signal value is less than the first amplitude threshold. In response to the invalid compensation count being less than or equal to the count threshold, the preset period is adjusted, and the first compensation current is re-determined based on the first operating parameters obtained according to the adjusted preset period. In response to the invalid compensation count exceeding the count threshold, the obtained first compensation current is attenuated.

12. The method according to claim 11, characterized in that, The method further includes: Output a prompt message, wherein the prompt message is used to indicate the possible causes of the three-phase current imbalance.

13. The method according to any one of claims 1 to 3, characterized in that, The step of determining the first compensation current corresponding to the first operating parameter based on the first mapping relationship includes: In response to the three-phase current imbalance of the motor, and the degree of imbalance of the three-phase current is greater than the degree of imbalance threshold, a first compensation current corresponding to the first operating parameter is determined based on the first mapping relationship.

14. The method according to any one of claims 1 to 3, characterized in that, In response to a three-phase current imbalance in the motor, where the imbalance degree is greater than an imbalance degree threshold, a first compensation current corresponding to the first operating parameter is determined based on the first mapping relationship, including: In response to the three-phase current imbalance of the motor, and the degree of imbalance of the three-phase current is greater than the degree of imbalance threshold, the degree of imbalance range in which the degree of imbalance is located is determined. In response to the imbalance being within a first imbalance range, a first compensation current corresponding to the first operating parameter is determined based on the first mapping relationship, wherein the lower limit of the first imbalance range is greater than the upper limit of the second imbalance range.

15. A device for handling three-phase current imbalance in a motor, characterized in that, include: The first acquisition module is configured to acquire first operating parameters in response to the three-phase current imbalance of the motor; wherein, the first operating parameters include the degree of imbalance of the three-phase current of the motor and the influence parameter corresponding to at least one phase current of the three-phase current. The first determining module is configured to determine the first compensation current corresponding to the first operating parameter based on the first mapping relationship; wherein, the first mapping relationship includes the mapping relationship between the operating parameter and the compensation current; The compensation module is configured to compensate the preset current of the motor based on the first compensation current to obtain the compensated current of the motor. The control module is configured to control the operation of the motor based on the compensated current of the motor.

16. A vehicle-mounted device, characterized in that, The in-vehicle device includes a memory and one or more processors, the memory storing a computer program that, when executed by the in-vehicle device, implements the method as described in any one of claims 1 to 14.

17. A vehicle, characterized in that, include: The vehicle-mounted device as claimed in claim 16; Electric motor.

18. A computer-readable storage medium, characterized in that, The readable storage medium stores executable instructions, wherein when the executable instructions are executed by a processor, they implement the processing method as described in any one of claims 1 to 14.

19. A computer program product, comprising a computer program or instructions, characterized in that, When the computer program or instructions are executed by a processor, they implement the method as described in any one of claims 1 to 14.

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