Phase delay diagnosis method of motor phase current, motor control system, equipment and medium

Abstract

The invention provides a phase delay diagnosis method of motor phase current, a motor control system, electronic equipment and a storage medium. The phase delay diagnosis method comprises the following steps: respectively sampling at least two paths of to-be-diagnosed phase currents of a motor in each electric period to obtain a first current value sampling sequence and a second current value sampling sequence; determining a first phase current diagnosis parameter corresponding to the first current parameter sampling sequence and a second phase current diagnosis parameter corresponding to the second current parameter sampling sequence according to a preset phase delay diagnosis rule; and if the deviation between the first phase current diagnosis parameter and the second phase current diagnosis parameter exceeds a preset phase delay error, determining that phase delay exists in the two to-be-diagnosed phase currents. According to the invention, when the phase delay of the collected current is caused by the failure of the current sensor or the sampling circuit of the motor control system, the failure scene of the phase delay is diagnosed in real time, so that the motor control system is triggered to enter a shutdown mode, and the motor control system can enter a safe state in time; and the functional safety requirement of the electric vehicle is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of motor control, and in particular to a phase delay diagnosis method for motor phase current, a motor control system, an electronic device and a storage medium. Background Art

[0002] With the increasing demand for environmental protection and the rapid development of science and technology, electric vehicles have become the future development trend. The torque control of electric vehicles is achieved by the current closed-loop control of the motor control system. For example, see Figure 1 , Figure 1 This is a structural block diagram of a motor control system in the related art. Figure 1 As can be seen, the motor control system includes a power supply battery 110, an inverter (motor controller) 120, a current sensor 130, and a motor 140. The current sensor 130 is provided on the three-phase wiring harness between the inverter 120 and the motor 140. The motor control system collects current information through the current sensor 130, performs coordinate transformation on the measured current information, and uses the transformed current information as feedback for the current loop, ultimately achieving closed-loop control.

[0003] However, the current sensor 130 and the related sampling circuit of the motor control system have a probability of random hardware failure. One of the manifestations after the failure will cause the current phase delay. The current phase delay will cause the motor control system of the electric vehicle to be unable to accurately control the current, and ultimately lead to a sudden change in current and torque, and the vehicle will be out of control. Driving safety cannot be guaranteed, and there is a huge safety hazard. Therefore, it is necessary to perform real-time diagnosis on whether the phase current has phase delay. Specifically, combined with Figure 2a and Figure 2b , taking the U phase and V phase as examples, the phase delay of the phase current is explained. Figure 2a Schematic diagram of waveform when the phase difference between the U-phase current and the V-phase current is normal (the phase difference electrical angle is 120°); Figure 2b Figure 1 is a waveform diagram of the U-phase current and the V-phase current when there is a phase delay (the phase difference electrical angle is 130°). Figure 2a As shown in , the ideal electrical angle of the phase current phase difference is 120°; when phase delay occurs, the phase difference will become larger, and the phase difference between one phase with phase delay and the other two phases will be greater or less than 120°, as shown in Figure 2b As shown, the electrical angle phase difference between the U-phase current and the V-phase current is 130°. For a motor control system using three current sensors 130, Kirchhoff's law can be used as shown in the following equation (1) to diagnose the above-mentioned phase delay failure. That is, when the sum of the three-phase current of the motor is zero, there is no phase delay fault; if the sum of the three-phase current is not zero, there is a phase delay fault.

[0004] Iu+Iv+Iw=0 (1)

[0005] In formula (1), Iu is the U-phase current, Iv is the V-phase current, and Iw is the W-phase current.

[0006] However, for motor control systems using only two current sensors 130, the "three-phase current sum is zero" diagnostic mechanism cannot be used to detect phase delay. This is because the third-phase current cannot be obtained through current sensor 130. For motor control systems using two current sensors 130, available public documentation and actual applications have not yet revealed clear and effective diagnostic mechanisms and technologies that can detect current phase delay.

[0007] It should be noted that the information disclosed in the background technology section of the invention is only intended to deepen the understanding of the general background technology of the invention, and should not be regarded as an admission or any form of implication that the information constitutes prior art already known to those skilled in the art. Summary of the Invention

[0008] The main purpose of the present invention is to provide a phase delay diagnosis method for motor phase current, a motor control system, an electronic device and a storage medium for a motor control system that uses only two current sensors, so as to diagnose the phase delay failure scenario in real time when the current sensor or its sampling circuit of the motor control system fails, causing the collected current to have a phase delay, thereby triggering the motor control system to enter a shutdown mode, so that the motor control system can enter a safe state in time, thereby ensuring the functional safety requirements of electric vehicles.

[0009] To achieve the above object, the present invention is implemented through the following technical solutions: a method for diagnosing phase delay of motor phase current, comprising:

[0010] In each electrical cycle, sampling at least two phase currents to be diagnosed of the motor is performed respectively to obtain a first current value sampling sequence and a second current value sampling sequence;

[0011] Determining, according to a preset phase delay diagnostic rule, a first phase current diagnostic parameter corresponding to the first current parameter sampling sequence and a second phase current diagnostic parameter corresponding to the second current parameter sampling sequence;

[0012] If the deviation between the first phase current diagnostic parameter and the second phase current diagnostic parameter exceeds a preset phase delay error, then there is a phase delay between the two phase currents to be diagnosed.

[0013] Optionally, determining the first phase current diagnostic parameter corresponding to the first current parameter sampling sequence and the second phase current diagnostic parameter corresponding to the second current parameter sampling sequence according to a preset phase delay diagnostic rule includes:

[0014] Taking any sampling point in the first current parameter sampling sequence as a first diagnostic point, and calculating a first motor rotor angle corresponding to the first diagnostic point;

[0015] Obtaining a second motor rotor angle whose absolute value of difference from the first motor rotor angle is 120°; obtaining a sampling point corresponding to the second motor rotor angle in the second current parameter sampling sequence, and using the sampling point as a second diagnostic point;

[0016] The first phase current value corresponding to the first diagnostic point is used as a first phase current diagnostic parameter, and the second phase current value corresponding to the second diagnostic point is used as a second phase current diagnostic parameter.

[0017] Optionally, taking any sampling point in the first current parameter sampling sequence as a first diagnostic point includes:

[0018] Taking the current sampling point in the first current parameter sampling sequence as the first diagnostic point;

[0019] and / or,

[0020] Obtaining a second motor rotor angle whose absolute value of difference from the first motor rotor angle is 120°, comprising:

[0021] A second electronic rotor angle that is 120° before the first motor rotor angle is obtained.

[0022] Optionally, if the deviation between the first phase current diagnostic parameter and the second phase current diagnostic parameter exceeds a preset phase delay error, then there is a phase delay between the two phase currents to be diagnosed, including:

[0023] It is determined whether the absolute value of the difference between the first phase current value and the second phase current value is less than a preset current delay error value; if not, a phase delay exists between the two phase currents to be diagnosed.

[0024] Optionally, the phase delay diagnosis method further includes:

[0025] It is determined whether the motor is in a torque mutation state. If so, the phase delay diagnosis is not enabled.

[0026] Optionally, the phase delay diagnosis method further includes: determining whether the duration of the phase delay between the two phase currents to be diagnosed exceeds a preset phase delay duration; if so, reporting a phase delay diagnosis fault.

[0027] Optionally, determining the first phase current diagnostic parameter corresponding to the first current parameter sampling sequence and the second phase current diagnostic parameter corresponding to the second current parameter sampling sequence according to a preset phase delay diagnostic rule includes:

[0028] In the same electrical cycle, obtaining a first maximum current value or a first minimum current value in the first current parameter sampling sequence and a second maximum current value or a second minimum current value in the second current parameter sampling sequence;

[0029] respectively obtaining a first phase angle corresponding to a sampling moment of the first maximum current value, a second phase angle corresponding to a sampling moment of the first minimum current value, a third phase angle corresponding to a sampling moment of the second maximum current value, and a fourth phase angle corresponding to a sampling moment of the second minimum current value;

[0030] The first phase angle is used as the first phase current diagnostic parameter, and the third phase angle is used as the second phase current diagnostic parameter; or the second phase angle is used as the first phase current diagnostic parameter, and the fourth phase angle is used as the second phase current diagnostic parameter.

[0031] Optionally, if the deviation between the first phase current diagnostic parameter and the second phase current diagnostic parameter exceeds a preset phase delay error, then there is a phase delay between the two phase currents to be diagnosed, including:

[0032] determining whether the absolute value of the difference between the first phase angle and the third phase angle is greater than a preset upper limit of the phase angle deviation or less than a preset lower limit of the phase angle deviation; if so, a phase delay exists between the two phase currents to be diagnosed;

[0033] or

[0034] Determine whether the absolute value of the difference between the second phase angle and the fourth phase angle is greater than a preset upper limit value of the phase angle deviation or less than a preset lower limit value of the phase angle deviation. If so, there is a phase delay in the two phase currents to be diagnosed.

[0035] In order to achieve the above object, the present invention further provides a motor control system for an electric vehicle, the motor control system comprising an inverter, a motor, and a phase delay diagnostic device, the phase delay diagnostic device comprising a sampling unit, a diagnostic information acquisition unit, and a diagnostic execution unit;

[0036] The inverter is configured to convert the direct current of the power supply battery into controllable three-phase alternating current to drive the motor;

[0037] The sampling unit is configured to sample at least two phase currents to be diagnosed of the motor in each electrical cycle to obtain a first current value sampling sequence and a second current value sampling sequence;

[0038] The diagnostic information acquisition unit is configured to determine a first phase current diagnostic parameter corresponding to the first current parameter sampling sequence and a second phase current diagnostic parameter corresponding to the second current parameter sampling sequence according to a preset phase delay diagnostic rule;

[0039] The diagnosis execution unit is configured to determine that there is a phase delay between the two phase currents to be diagnosed if a deviation between the first phase current diagnosis parameter and the second phase current diagnosis parameter exceeds a preset phase delay error.

[0040] In order to achieve the above-mentioned purpose, the present invention also provides an electronic device, which includes a processor and a memory, and a computer program is stored in the memory. When the computer program is executed by the processor, the phase delay diagnosis method of the motor phase current described in any one of the above-mentioned items is implemented.

[0041] In order to achieve the above-mentioned object, the present invention further provides a readable storage medium, in which a computer program is stored. When the computer program is executed by a processor, the phase delay diagnosis method of the motor phase current described in any one of the above-mentioned items is implemented.

[0042] Compared with the prior art, the motor phase current phase delay diagnosis method, motor control system, electronic device, and storage medium provided by the present invention have the following advantages:

[0043] The phase delay diagnosis method for motor phase current provided by the present invention first samples at least two phase currents to be diagnosed of the motor in each electrical cycle to obtain a first current value sampling sequence and a second current value sampling sequence. Then, according to a preset phase delay diagnosis rule (for example, comparing whether the difference in the current values of the sampling points where the phase angles of the two phase currents differ by 120° is within a preset threshold), the first phase current diagnostic parameter corresponding to the first current parameter sampling sequence and the second phase current diagnostic parameter corresponding to the second current parameter sampling sequence are determined. Finally, it is determined whether the deviation between the first phase current diagnostic parameter and the second phase current diagnostic parameter exceeds a preset phase delay error. If so, the two phase currents to be diagnosed have a phase delay. With such a configuration, the phase delay diagnosis method for motor phase current provided by the present invention can diagnose the phase delay in real time when the current sensor or its sampling circuit of the motor control system fails, causing the collected current to have a phase delay, thereby triggering the motor control system to enter a shutdown mode, so that the motor control system can enter a safe state in a timely manner; thereby laying a solid foundation for ensuring the functional safety requirements of electric vehicles. Therefore, the phase delay diagnosis method of the motor phase current provided by the present invention can timely diagnose the failure state of the phase delay of the phase current, thereby avoiding the continued operation of the motor control system of the electric vehicle, resulting in vehicle instability, unexpected acceleration and unexpected deceleration and other unexpected consequences, and can ensure that the functional safety of the electric vehicle is within a controllable range, thereby laying a solid foundation for protecting the lives of drivers and passengers.

[0044] Since the motor control system, electronic device and storage medium provided by the present invention belong to the same inventive concept as the phase delay diagnosis method of the motor phase current provided by the present invention, the motor control system, electronic device and storage medium provided by the present invention have at least all the advantages of the phase delay diagnosis method of the motor phase current provided by the present invention. For details, please refer to the above description of the beneficial effects of the phase delay diagnosis method of the motor phase current, and no further details will be given here. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 A block diagram of a motor control system in the related art;

[0046] Figure 2a Schematic diagram of waveform when the phase difference between the U-phase current and the V-phase current is normal (the phase difference electrical angle is 120°);

[0047] Figure 2b Schematic diagram of the waveform when the U-phase current and the V-phase current are phase delayed (the phase difference electrical angle is 130°);

[0048] Figure 3A schematic diagram of the overall flow of a method for diagnosing phase delay of motor phase current provided by a first embodiment of the present invention;

[0049] Figure 4 A schematic diagram illustrating the principle of a method for diagnosing phase delay of motor phase current provided by a first embodiment of the present invention;

[0050] Figure 5 A schematic diagram showing the correspondence between the first current parameter sampling sequence and the second current parameter sampling sequence and the first diagnostic point and the second diagnostic point in one specific example of the method for diagnosing phase delay of motor phase current provided by the first embodiment of the present invention;

[0051] Figure 6a 2. A waveform diagram of a diagnosis performed by “shifting the V-phase current” in a specific example when there is no phase delay between the U-phase current and the V-phase current;

[0052] Figure 6b 2. A waveform diagram of a diagnosis performed by "shifting the V-phase current" when there is a phase delay between the U-phase current and the V-phase current in one specific example;

[0053] Figure 7 A structural block diagram of a motor control system for an electric vehicle provided by a third embodiment of the present invention;

[0054] Figure 8 A schematic block diagram of an electronic device according to a fourth embodiment of the present invention.

[0055] The accompanying drawings are numerals as follows:

[0056] Power supply battery 110, inverter 120, current sensor 130, motor 140, phase delay diagnostic device 150, sampling unit 151, diagnostic information acquisition unit 152, diagnostic execution unit 153;

[0057] Processor 210 , communication interface 220 , memory 230 , communication bus 240 . DETAILED DESCRIPTION

[0058] The following, in conjunction with the accompanying drawings, further details the motor phase current phase delay diagnosis method, motor control system, electronic device, and storage medium proposed in the present invention. The following description will further clarify the advantages and features of the present invention. It should be noted that the drawings are simplified and not precisely scaled, and are intended solely to facilitate and clearly illustrate the purpose of the embodiments of the present invention. To make the purposes, features, and advantages of the present invention more readily apparent, please refer to the drawings. It should be noted that the structures, proportions, and sizes illustrated in the drawings of this specification are intended solely to facilitate understanding and reading by those skilled in the art, and are not intended to limit the implementation of the present invention. Any structural modifications, changes in proportions, or adjustments in size, provided they produce the same or similar effects and achieve the same objectives as the present invention, should still fall within the scope of the technical content disclosed herein. The specific design features of the present invention disclosed herein, including, for example, specific dimensions, directions, positions, and shapes, will be determined in part by the specific application and use environment. Furthermore, in the embodiments described below, the same reference numerals may be used across different drawings to represent the same parts or parts with the same functions, and their repeated descriptions may be omitted. In this specification, similar reference numerals and letters are used to refer to similar items, so once an item is defined in one figure, it need not be further discussed in subsequent figures. In addition, if the method described herein includes a series of steps, the order in which the steps are presented herein is not necessarily the only order in which the steps can be performed, and some of the steps described may be omitted and / or some other steps not described herein may be added to the method.

[0059] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element. The singular forms "a", "an" and "the" include plural objects, the term "or" is generally used in a sense including "and / or", the term "several" is generally used in a sense including "at least one", and the term "at least two" is generally used in a sense including "two or more". In addition, the terms "first", "second" and "third" are used for descriptive purposes only and cannot be understood as indicating or suggesting relative importance or implicitly indicating the number of the indicated technical features.

[0060] The core idea of the present invention is to provide a phase delay diagnosis method for motor phase current, a motor control system, an electronic device and a storage medium for a motor control system that uses only two current sensors. When the current sensor or its sampling circuit of the motor control system fails, causing a phase delay in the collected current, the method can diagnose the phase delay failure scenario in real time, thereby triggering the motor control system to enter the shutdown mode, so that the motor control system can enter a safe state in time; thereby ensuring the functional safety requirements of electric vehicles.

[0061] It should be noted that those skilled in the art should be able to understand that the "motor control system for using only two current sensors" mentioned above can mean that the motor control system of the electric vehicle itself has only two current sensors for collecting current information, or that the motor control system of the electric vehicle originally has three current sensors for collecting current information, but one of the current sensors fails, and only the other two current sensors that can work normally are used to collect phase current. It should be further noted that although the phase delay diagnosis method of the motor phase current provided in this article is mainly aimed at the motor control system using only two current sensors, it is not difficult to find from the content disclosed in this article that the phase delay diagnosis method of the motor phase current provided by the present invention is not limited to the motor control system using two current sensors, and the present invention is also applicable to the motor control system using three current sensors.

[0062] It should also be noted that the phase delay diagnosis method of the motor phase current provided by the present invention can be applied to the motor control system and electronic equipment provided by the present invention. The electronic equipment provided by the present invention can be deployed on the motor control system provided by the present invention. The motor control system provided by the present invention can be deployed on electric vehicles, and the electric vehicles include but are not limited to family cars, sports utility vehicles (SUVs), buses, trucks and various commercial vehicles.

[0063] To realize the above idea, the first embodiment of the present invention provides a method for diagnosing phase delay of motor phase current. Figure 3 , Figure 3 The overall flow chart of the phase delay diagnosis method of the motor phase current provided in this embodiment is as follows. Figure 3 It can be seen that the phase delay diagnosis method of the motor phase current provided in this embodiment includes:

[0064] S100: In each electrical cycle, sampling at least two phase currents to be diagnosed of the motor respectively to obtain a first current value sampling sequence and a second current value sampling sequence;

[0065] S200: Determine, according to a preset phase delay diagnosis rule, a first phase current diagnostic parameter corresponding to the first current parameter sampling sequence and a second phase current diagnostic parameter corresponding to the second current parameter sampling sequence;

[0066] S300: If the deviation between the first phase current diagnostic parameter and the second phase current diagnostic parameter exceeds a preset phase delay error, a phase delay exists between the two phase currents to be diagnosed.

[0067] It can be seen that the phase delay diagnosis method of the motor phase current provided by the present invention first samples at least two phase currents to be diagnosed of the motor in each electrical cycle to obtain a first current value sampling sequence and a second current value sampling sequence, and then determines the first phase current diagnostic parameter corresponding to the first current parameter sampling sequence and the second phase current diagnostic parameter corresponding to the second current parameter sampling sequence according to the preset phase delay diagnosis rule (for example, comparing whether the difference between the current values of the sampling points where the phase angles of the two phase currents differ by 120° is within a preset threshold), and finally determines whether the deviation between the first phase current diagnostic parameter and the second phase current diagnostic parameter exceeds the preset phase delay error. If so, the two phase currents to be diagnosed have a phase delay. With such a configuration, the phase delay diagnosis method of the motor phase current provided by the present invention can diagnose the phase delay in real time when the current sensor or its sampling circuit of the motor control system fails, causing the collected current to have a phase delay, thereby triggering the motor control system to enter the shutdown mode, so that the motor control system can enter a safe state in a timely manner; thereby laying a solid foundation for ensuring the functional safety requirements of electric vehicles. Therefore, the phase delay diagnosis method of the motor phase current provided by the present invention can timely diagnose the failure state of the phase delay of the phase current, thereby avoiding the continued operation of the motor control system of the electric vehicle, resulting in vehicle instability, unexpected acceleration and unexpected deceleration and other unexpected consequences, and can ensure that the functional safety of the electric vehicle is within a controllable range, thereby laying a solid foundation for protecting the lives of drivers and passengers.

[0068] In order to facilitate the understanding and explanation of the present invention, this article takes the phase deviation between the U-phase current and the V-phase current as an example to illustrate the phase delay diagnosis method of the motor phase current provided by the present invention, but it should be understood that this is only an exemplary description of the preferred embodiment, and not a limitation of the present invention. It should be further explained that, as those skilled in the art can understand, the present invention does not limit the sampling frequency of the current values of the first current value sampling sequence and the second current value sampling sequence, but it can be understood that the higher the sampling frequency, the more accurate the diagnostic result. Furthermore, the sampling frequencies of the two phase currents to be diagnosed can be the same or different. However, as a preferred embodiment, synchronous sampling of the two phase currents to be diagnosed not only has higher diagnostic efficiency, but also can make the diagnostic results have higher accuracy.

[0069] Preferably, in some exemplary embodiments, determining the first phase current diagnostic parameter corresponding to the first current parameter sampling sequence and the second phase current diagnostic parameter corresponding to the second current parameter sampling sequence according to a preset phase delay diagnostic rule in step 200 specifically includes:

[0070] S211: Taking any sampling point in the first current parameter sampling sequence as a first diagnostic point, and calculating a first motor rotor angle corresponding to the first diagnostic point;

[0071] S212: Calculate a second motor rotor angle whose absolute value of difference from the first motor rotor angle is 120°; obtain a sampling point corresponding to the second motor rotor angle in the second current parameter sampling sequence, and use the sampling point as a second diagnostic point;

[0072] S213: Using the first phase current value corresponding to the first diagnostic point as a first phase current diagnostic parameter, and using the second phase current value corresponding to the second diagnostic point as a second phase current diagnostic parameter.

[0073] Therefore, the phase delay diagnosis method of the motor phase current provided by the present invention corresponds a first diagnostic point and a second diagnostic point where the absolute value of the difference between the motor rotor angles is 120°, and uses the first phase current value corresponding to the first diagnostic point as the first phase current diagnostic parameter, and uses the second phase current value corresponding to the second diagnostic point as the second phase current diagnostic parameter. By shifting the electrical angle of one of the phase currents to be diagnosed by 120°, a solid foundation is laid for realizing phase delay diagnosis.

[0074] As is known to those skilled in the art, the phase difference of the three-phase winding of the motor is 120 degrees in electrical angle. Figure 4 , Figure 4 The schematic diagram of the principle of the phase delay diagnosis method of the motor phase current provided by the first embodiment of the present invention. Figure 4 It can be seen that, taking the U-phase current and the V-phase current as an example, when the sampling phase signal delay occurs in either the U-phase or V-phase current sensor, the phase difference between it and the other phase (V-phase or U-phase) will be greater than or less than 120° in electrical angle. The U-phase current and the V-phase current can be expressed by the following equations (2) and (3):

[0075] Iu=Imax×sinωt (2)

[0076] Iv=Imax×(sinωt+120) (3)

[0077] In the above formulas (2) and (3), Imax is the maximum current, Iu in formula (2) is the instantaneous current of phase U at time t, and Iv is the instantaneous current of phase V at time t. Figure 4 It can be seen that in the absence of phase delay, if the V-phase current phase is shifted by 120° to coincide with the U-phase current phase, recorded as Iv', the actual difference between Iu and Iv' at the same sampling time t is calculated by the following formula (4):

[0078] Idif=Abs(Iu - Iv') (4)

[0079] In the above formula (4), Idif is the actual difference between the U-phase current and the V-phase current, Iu is the current waveform of the U-phase, and Iv' is the current waveform when the phase current is shifted by 120 degrees. Figure 4 It is not difficult to find that under normal circumstances, the waveform of Iv' should coincide with the waveform of Iu, that is, under normal circumstances, the value of Idif should be 0 at any time; if the value of Idif is too large and the difference continues to be too large within the electrical cycle, it can be determined that there is a phase delay between the U phase and the V phase (that is, there is a signal delay).

[0080] The phase delay diagnosis method of the motor phase current provided by the present invention performs phase delay diagnosis based on the basic fact that the two phase currents to be diagnosed with an electrical angle difference of 120° have "equal phase current values after electrical angle shift" as the phase delay diagnosis rule.

[0081] Preferably, in some exemplary embodiments, in step S211, using any sampling point in the first current parameter sampling sequence as the first diagnostic point specifically includes using the current sampling point in the first current parameter sampling sequence as the first diagnostic point. This configuration, by using the current sampling point in the first current parameter sampling sequence as the first diagnostic point, can improve the real-time performance and accuracy of phase delay diagnosis.

[0082] Preferably, in some exemplary embodiments, obtaining the second motor rotor angle whose absolute value of difference from the first motor rotor angle is 120° in step S212 specifically includes:

[0083] A second electronic rotor angle that is 120° before the first motor rotor angle is obtained.

[0084] Therefore, the phase delay diagnosis method of the motor phase current provided by the present invention can further improve the real-time performance and accuracy of the phase delay diagnosis.

[0085] For example, see Figure 5 , Figure 5 A schematic diagram of the correspondence between the first current parameter sampling sequence and the second current parameter sampling sequence and the first diagnostic point and the second diagnostic point in one specific example of the motor phase current phase delay diagnosis method provided by the first embodiment of the present invention. Figure 5 It can be seen that in this example, the U-phase current and the V-phase current are cached from time T+1, which are recorded as Iu and T+1 and Iu T+1 , at time T+2, respectively denoted as Iu T+2 and Iu T+2, and so on, and the following formula (5) is satisfied between T+12 and T+1:

[0086] Abs(θ T+12 -θ T+1 )≈120°(5)

[0087] In formula (5), θ T+12 is the motor rotor angle at time T+12, θ T+1 =The motor rotor angle at time T+1 is θ, meaning the absolute difference between the motor rotor angle θ at time T+12 and at time T+1 is approximately 120°. Therefore, starting at time T+12, phase delay diagnosis can be performed using the fundamental fact that phase currents remain equal after electrical angle shifts.

[0088] Preferably, in some preferred embodiments, if the deviation between the first phase current diagnostic parameter and the second phase current diagnostic parameter exceeds a preset phase delay error in step S300, then there is a phase delay between the two phase currents to be diagnosed, specifically including:

[0089] It is determined whether the absolute value of the difference between the first phase current value and the second phase current value is less than a preset current delay error value; if not, a phase delay exists between the two phase currents to be diagnosed.

[0090] Therefore, the phase delay diagnosis method for motor phase current provided by the present invention is simple and easy to implement. It should be noted that, as those skilled in the art will appreciate, the present invention does not impose any limitation on the specific value of the preset phase delay error, and the specific value of the preset phase delay error should be reasonably set according to actual conditions.

[0091] For example, please combine Figure 5 In some embodiments, the phase current Iv of the V phase can be calculated T+12 Phase current Iu of phase U T+1 The absolute value of the difference between the V phase current Iv T+13 Phase current Iu of phase U T+2 The absolute value of the difference between the V phase current Iv T+14 Phase current Iu of phase U T+3 Whether the absolute value of the difference between , ... is greater than a preset phase delay error (for example, 30A), if so, there is a phase delay phenomenon; if not, there is no phase delay phenomenon.

[0092] It should be noted that, as those skilled in the art will appreciate, the method described herein for diagnosing whether a phase delay has occurred based on a comparison of the absolute value of the difference between the first-phase current value and the second-phase current value with a preset current delay error value is merely illustrative of a preferred embodiment and is not intended to limit the present invention. For example, in other embodiments, phase delay diagnosis may also be performed based on a comparison of the ratio between the first-phase current value and the second-phase current value with a preset threshold value. These examples are not further detailed here.

[0093] Please continue to see Figure 1 In some exemplary embodiments, the phase delay diagnosis method further includes:

[0094] S400: Determine whether the duration of the phase delay between the two phase currents to be diagnosed exceeds a preset phase delay duration. If so, report a phase delay diagnosis fault.

[0095] Therefore, the phase delay diagnosis method of the motor phase current provided by the present invention reports a phase delay diagnosis fault when the duration of the phase delay between the two phase currents to be diagnosed exceeds the preset phase delay duration, which can reduce the risk of misjudgment, thereby improving the reliability and stability of the phase delay diagnosis. It should be noted that, as those skilled in the art can understand, the present invention does not limit the specific value of the preset phase delay duration, and the specific value of the preset phase delay duration should be reasonably set according to actual conditions. For example, in some exemplary embodiments, the sampling frequency can be set to a multiple of the electrical frequency (such as 10 times), and the preset phase delay duration can be set to the number of consecutive phase delays of 1300 times.

[0096] Furthermore, when a phase delay diagnostic fault is reported, the motor control system can be triggered to stop running, thereby entering a shutdown safety state, thereby avoiding the electric vehicle's motor control system from continuing to run, resulting in vehicle instability, unexpected acceleration and unexpected deceleration and other unexpected consequences, and ensuring the functional safety of the electric vehicle within a controllable range, thereby ensuring the life safety of the driver and passengers.

[0097] Please continue to see Figure 1 In some exemplary embodiments, the phase delay diagnosis method further includes:

[0098] Before executing the phase delay diagnosis (for example, before executing step S300 ), it is determined whether the motor is in a torque mutation state. If so, the phase delay diagnosis is not enabled.

[0099] Therefore, phase delay diagnosis is performed only when the motor is in a non-torque mutation state, which can reduce the adverse effects of transient states such as torque mutations and acceleration and deceleration processes on the effectiveness of phase delay diagnosis, thereby further improving the effectiveness and robustness of the phase delay diagnosis method of the motor phase current provided by the present invention.

[0100] It should be noted that those skilled in the art should be able to understand that the present invention does not further limit the specific method for determining whether the motor is in a torque mutation state. For example, in some embodiments, it can be determined whether the torque fluctuation of the torque command within each electrical cycle is less than the torque fluctuation preset value. If so, the phase delay diagnosis is enabled (step S300 is executed); if not, the phase delay diagnosis is not enabled (step S300 is not executed). In other embodiments, it can be determined whether the torque fluctuation of the actual torque within each electrical cycle is less than the torque fluctuation preset value. If so, the phase delay diagnosis is enabled (step S300 is executed); if not, the phase delay diagnosis is not enabled (step S300 is not executed). It should be understood that the above-mentioned method for determining whether the motor is in a torque mutation state is only an exemplary description of a preferred embodiment and is not a limitation of the present invention. In other embodiments, related technologies known to those skilled in the art for determining whether the motor is in a torque mutation state other than the above two methods may also be used, which are not listed here one by one. It should be noted that, as those skilled in the art will appreciate, the present invention does not limit the specific value of the torque fluctuation preset value, and the specific value of the torque fluctuation preset value should be reasonably set according to actual conditions. For example, the torque fluctuation preset value can be set to 3%.

[0101] To facilitate understanding of the present invention, the following will further illustrate the phase delay diagnosis method of the motor phase current provided by the present invention using the U phase and the V phase as examples. In this example, the phase delay diagnosis of the motor phase current is mainly performed through the following steps:

[0102] SA1: In each electrical cycle (i.e. PMW cycle), the instantaneous values of the U-phase and V-phase currents are sampled in real time at each moment, and then stored in the cache array. Data caching starts from time T+1, which is recorded as Iu T+1 , Iv T+1 ...;

[0103] SA2: Real-time calculation of the motor rotor angle, judging when Abs(θ T+i -θ T+1 ) When the angle is equal to 120°, compare the V-phase current value at this moment with the U-phase current value 120° before, for example, calculate: I dif =Abs(Iu T+1 -Iu T+12 ), I dif =Abs(IuT+2 -Iu T+13 )……, data caching starts from time T+1, denoted as θ T+1 ...;

[0104] SA3: Calculates the torque fluctuation of the torque command within each electrical cycle and determines in real time that when the fluctuation is less than 3%, phase delay diagnosis is enabled;

[0105] SA4: When the U-phase current at time T+12+i and the V-phase current at time T+1+i deviate I dif If the current is greater than 30A (the preset value of the current delay error) and continues for a certain period of time, a diagnostic fault will be reported. The fault will immediately trigger the motor control system to stop running, thus entering the shutdown safety state.

[0106] For example, see Figure 6a and Figure 6b ,in, Figure 6a 2. A waveform diagram of a diagnosis performed by “shifting the V-phase current” in a specific example when there is no phase delay between the U-phase current and the V-phase current; Figure 6b FIG. 1 is a waveform diagram of a diagnosis using “translation of V-phase current” when there is a phase delay between the U-phase current and the V-phase current in a specific example. Figure 6a and Figure 6b It can be seen that the phase delay diagnosis method of the motor phase current provided by the present invention can timely diagnose the failure state of the phase delay of the phase current, thereby avoiding the continued operation of the motor control system of the electric vehicle leading to vehicle instability, unexpected acceleration and unexpected deceleration and other unexpected consequences, and can ensure the functional safety of the electric vehicle within a controllable range, thereby laying a solid foundation for protecting the lives of drivers and passengers.

[0107] The second embodiment of the present invention provides another method for diagnosing the phase delay of a motor phase current. The method for diagnosing the phase delay of a motor phase current provided in this embodiment is basically the same as the method for diagnosing the phase delay of a motor phase current provided in the first embodiment. It also includes step S100, in which at least two phase currents to be diagnosed of the motor are sampled separately in each electrical cycle to obtain a first current value sampling sequence and a second current value sampling sequence. Steps S200 and S300 are also based on the basic fact that the two phase currents to be diagnosed with an electrical angle difference of 120° have "equal phase current values after electrical angle shift" as a phase delay diagnosis rule to perform phase delay diagnosis. However, the difference from the first embodiment is that the method for diagnosing the phase delay of a motor phase current provided in this embodiment is slightly different from the steps S200 and S300 of the method for diagnosing the phase delay of a motor phase current provided in the first embodiment. To avoid redundancy, only the differences between this example and the first embodiment are described below. For parts not mentioned in this embodiment, please refer to the relevant description of the first embodiment for adaptive understanding.

[0108] For example, the phase delay diagnosis method for motor phase current provided in this embodiment, in step S200, determining the first phase current diagnostic parameter corresponding to the first current parameter sampling sequence and the second phase current diagnostic parameter corresponding to the second current parameter sampling sequence according to the preset phase delay diagnosis rule, specifically includes:

[0109] S221: within the same electrical cycle, obtaining a first maximum current value or a first minimum current value in the first current parameter sampling sequence and a second maximum current value or a second minimum current value in the second current parameter sampling sequence;

[0110] S222: Obtain a first phase angle corresponding to the sampling moment of the first maximum current value, a second phase angle corresponding to the sampling moment of the first minimum current value, a third phase angle corresponding to the sampling moment of the second maximum current value, and a fourth phase angle corresponding to the sampling moment of the second minimum current value;

[0111] S223: Use the first phase angle as the first phase current diagnostic parameter and the third phase angle as the second phase current diagnostic parameter; or use the second phase angle as the first phase current diagnostic parameter and the fourth phase angle as the second phase current diagnostic parameter.

[0112] So configured, the phase delay diagnosis method of the motor phase current provided by the present invention adopts the phase angle corresponding to the maximum current value or the minimum current value of the two phase currents to be diagnosed in the same electrical cycle as the first phase current diagnostic parameter and the second phase current diagnostic parameter. The logic is simple and easy to implement, thereby laying a solid foundation for realizing phase delay diagnosis.

[0113] Correspondingly, in some exemplary embodiments, if the deviation between the first phase current diagnostic parameter and the second phase current diagnostic parameter exceeds a preset phase delay error, then there is a phase delay between the two phase currents to be diagnosed, specifically including:

[0114] Determine whether the absolute value of the difference between the first phase angle and the third phase angle is greater than a preset upper limit value of the phase angle deviation or less than a preset lower limit value of the phase angle deviation. If so, there is a phase delay between the two phase currents to be diagnosed.

[0115] Correspondingly, in some other exemplary embodiments, if the deviation between the first phase current diagnostic parameter and the second phase current diagnostic parameter exceeds a preset phase delay error, then there is a phase delay between the two phase currents to be diagnosed, specifically including:

[0116] Determine whether the absolute value of the difference between the second phase angle and the fourth phase angle is greater than a preset upper limit value of the phase angle deviation or less than a preset lower limit value of the phase angle deviation. If so, there is a phase delay in the two phase currents to be diagnosed.

[0117] Therefore, the phase delay diagnosis method of the motor phase current provided by the present invention calculates the maximum and / or minimum phase angle of the phase current to be diagnosed within the phase current cycle in real time, and compares whether the deviation of the maximum or minimum phase angles of the two-phase currents is greater than the preset upper limit of the phase angle deviation or less than the preset lower limit of the phase angle deviation, to determine whether a phase delay occurs. The phase delay can be diagnosed in real time, thereby triggering the motor control system to enter the shutdown mode, so that the motor control system can enter a safe state in time; thereby laying a solid foundation for ensuring the functional safety requirements of electric vehicles.

[0118] It should be noted that, as those skilled in the art can understand, the present invention does not limit the preset upper limit value of the phase angle deviation and the preset lower limit value of the phase angle deviation. For example, if the phase angle error of the phase current phase delay of the motor control system is less than or equal to the safety margin A, the safe driving of the electric vehicle can be guaranteed, then the preset upper limit value of the phase angle deviation can be set to (120° + safety margin A), and the preset lower limit value of the phase angle deviation can be set to (120° - safety margin A). However, it should be understood that the specific value of the safety margin A, that is, the specific acquisition method, is not limited in any way. For example, in some embodiments, it can be calculated using an algorithm according to the actual working conditions; in other embodiments, it can be obtained by calibration. I will not go into details here.

[0119] A third embodiment of the present invention provides a motor control system for an electric vehicle. For example, see Figure 7 , Figure 7 This is a structural block diagram of the motor control system of the electric vehicle provided in this embodiment. Figure 7 It can be seen that the motor control system provided in this embodiment includes an inverter 120 , a motor 140 and a phase delay diagnostic device 150 ; and the phase delay diagnostic device 150 includes a sampling unit 151 , a diagnostic information acquisition unit 152 and a diagnostic execution unit 153 .

[0120] Specifically, the inverter 120 is configured to convert the direct current of the power supply battery 110 into controllable three-phase alternating current to drive the motor 140. The sampling unit 151 is configured to sample at least two phase currents to be diagnosed of the motor 140 in each electrical cycle to obtain a first current value sampling sequence and a second current value sampling sequence. The diagnostic information acquisition unit 152 is configured to determine the first phase current diagnostic parameter corresponding to the first current parameter sampling sequence and the second phase current diagnostic parameter corresponding to the second current parameter sampling sequence according to a preset phase delay diagnostic rule. The diagnostic execution unit 153 is configured to determine that if the deviation between the first phase current diagnostic parameter and the second phase current diagnostic parameter exceeds a preset phase delay error, then there is a phase delay between the two phase currents to be diagnosed.

[0121] The electric vehicle motor control system provided by the present invention can diagnose the phase delay in real time when the current sensor 130 or its sampling circuit in the motor control system fails, causing the collected current to have a phase delay, thereby triggering the motor control system to enter a shutdown mode, allowing the motor control system to enter a safe state in a timely manner; thereby laying a solid foundation for ensuring the functional safety requirements of electric vehicles. Therefore, the electric vehicle motor control system provided by the present invention can promptly diagnose the failure state of the phase delay of the phase current, thereby avoiding the unintended consequences such as vehicle instability, undesirable acceleration and undesirable deceleration caused by the continued operation of the electric vehicle motor control system, and can ensure that the functional safety of the electric vehicle is within a controllable range, thereby laying a solid foundation for protecting the lives of drivers and passengers.

[0122] In addition, since the basic principles of the motor control system provided by the present invention and the phase delay diagnosis method of the motor phase current provided by the present invention are the same, in order to avoid redundancy, the phase delay diagnosis device 150 of the motor control system provided by the present invention will not be described in detail here. For more detailed information on how the phase delay diagnosis device 150 realizes the phase delay diagnosis of the motor phase current, please refer to the relevant content of the phase delay diagnosis method of the motor phase current provided by the first embodiment or the second embodiment of the present invention for adaptive understanding.

[0123] It should be noted that, as those skilled in the art will appreciate, the motor control system provided by the present invention may also include other components such as the current sensor 130. For more details, please refer to the relevant content of the motor control system for electric vehicles known to those skilled in the art for adaptive understanding, and will not be listed here one by one.

[0124] A fourth embodiment of the present invention provides an electronic device, please refer to Figure 8 , which schematically shows a block diagram of an electronic device provided by one embodiment of the present invention. Figure 8 As shown, the electronic device includes a processor 210 and a memory 230. The memory 230 stores a computer program. When the computer program is executed by the processor 210, it implements the phase delay diagnosis method for the motor phase current described above. Since the electronic device provided by the present invention and the phase delay diagnosis method for the motor phase current provided by the present invention are based on the same inventive concept, the electronic device provided by the present invention has at least all the advantages of the phase delay diagnosis method for the motor phase current provided by the present invention. For details, please refer to the relevant description of the beneficial effects of the phase delay diagnosis method for the motor phase current above, and no further details will be given here.

[0125] like Figure 8 As shown, the electronic device further includes a communication interface 220 and a communication bus 240, wherein the processor 210, the communication interface 220, and the memory 230 communicate with each other via the communication bus 240. The communication bus 240 may be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. The communication bus 240 may be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, only one thick line is used in the figure, but this does not mean that there is only one bus or one type of bus. The communication interface 220 is used for communication between the above-mentioned electronic device and other devices.

[0126] The processor 210 referred to in the present invention may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor. The processor 210 is the control center of the electronic device, connecting various parts of the entire electronic device using various interfaces and lines.

[0127] The memory 230 may be used to store the computer program. The processor 210 implements various functions of the electronic device by running or executing the computer program stored in the memory 230 and calling the data stored in the memory 230.

[0128] The memory 230 may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct RAMbus dynamic RAM (DRDRAM), and RAMbus dynamic RAM (RDRAM).

[0129] A fifth embodiment of the present invention provides a readable storage medium, wherein the readable storage medium stores a computer program. When the computer program is executed by a processor, the phase delay diagnosis method of the motor phase current described above can be implemented.

[0130] The readable storage medium of the embodiment of the present invention can adopt any combination of one or more computer-readable media. The readable medium can be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium can be, for example, but not limited to, a system, device or component of electricity, magnetism, light, electromagnetic, infrared or semiconductor, or any combination thereof. More specific examples (non-exhaustive list) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer hard disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In this article, a computer-readable storage medium can be any tangible medium containing or storing a program, which can be used by an instruction execution system, device or device or used in combination with it.

[0131] A computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, which carries computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium that can transmit, propagate, or transport a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0132] Computer program code for performing the operations of the present invention may be written in one or more programming languages, or a combination thereof, including object-oriented programming languages such as Java, Smalltalk, C++, and conventional procedural programming languages such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a stand-alone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., through the Internet using an Internet service provider).

[0133] Compared with the prior art, the motor phase current phase delay diagnosis method, motor control system, electronic device, and storage medium provided by the present invention have the following advantages:

[0134] The motor phase current phase delay diagnosis method provided by the present invention can diagnose the phase delay in real time when the current sensor or its sampling circuit of the motor control system fails, causing the collected current to have a phase delay, thereby triggering the motor control system to enter a shutdown mode, allowing the motor control system to enter a safe state in a timely manner; thereby laying a solid foundation for ensuring the functional safety requirements of electric vehicles. Therefore, the motor phase current phase delay diagnosis method provided by the present invention can timely diagnose the failure state of the phase delay of the phase current, thereby avoiding the continued operation of the motor control system of the electric vehicle, resulting in vehicle instability, unexpected acceleration and unexpected deceleration and other unexpected consequences, and can ensure that the functional safety of the electric vehicle is within a controllable range, thereby laying a solid foundation for protecting the lives of drivers and passengers.

[0135] Since the motor control system, electronic device and storage medium provided by the present invention belong to the same inventive concept as the phase delay diagnosis method of the motor phase current provided by the present invention, the motor control system, electronic device and storage medium provided by the present invention have at least all the advantages of the phase delay diagnosis method of the motor phase current provided by the present invention. For details, please refer to the above description of the beneficial effects of the phase delay diagnosis method of the motor phase current, and no further details will be given here.

[0136] It should be noted that the devices and methods disclosed in the embodiments of this document may also be implemented in other ways. The device embodiments described above are merely illustrative. For example, the flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of the devices, methods, and computer program products according to the various embodiments of this document. In this regard, each box in the flowchart or block diagram may represent a module, program, or portion of code, wherein the module, program segment, or portion of code contains one or more executable instructions for implementing a specified logical function, and the module, program segment, or portion of code contains one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the boxes may also occur in an order different from that marked in the accompanying drawings. For example, two consecutive boxes may actually be executed substantially in parallel, or they may sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart, may be implemented by a dedicated hardware-based system for performing the specified function or action, or may be implemented by a combination of dedicated hardware and computer instructions.

[0137] In addition, the functional modules in the various embodiments of this document may be integrated together to form an independent part, or each module may exist independently, or two or more modules may be integrated to form an independent part.

[0138] The above description is merely a description of preferred embodiments of the present invention and does not limit the scope of the present invention. Any changes or modifications made by persons skilled in the art based on the above disclosure are within the scope of protection of the present invention. Obviously, various modifications and variations may be made by persons skilled in the art without departing from the spirit and scope of the present invention. Thus, if such modifications and variations fall within the scope of the present invention and its equivalents, the present invention is intended to include such modifications and variations.

Claims

1. A method for diagnosing phase delay of motor phase current, characterized in that: include: In each electrical cycle, sampling is performed on at least two phase currents to be diagnosed of the motor to obtain a first current value sampling sequence and a second current value sampling sequence; Determining, according to a preset phase delay diagnostic rule, a first phase current diagnostic parameter corresponding to the first current parameter sampling sequence and a second phase current diagnostic parameter corresponding to the second current parameter sampling sequence; If the deviation between the first phase current diagnostic parameter and the second phase current diagnostic parameter exceeds a preset phase delay error, then there is a phase delay between the two phase currents to be diagnosed.

2. The phase delay diagnosis method according to claim 1, characterized in that: The determining, according to a preset phase delay diagnosis rule, a first phase current diagnostic parameter corresponding to the first current parameter sampling sequence and a second phase current diagnostic parameter corresponding to the second current parameter sampling sequence includes: Taking any sampling point in the first current parameter sampling sequence as a first diagnostic point, and calculating a first motor rotor angle corresponding to the first diagnostic point; Obtaining a second motor rotor angle whose absolute value of difference from the first motor rotor angle is 120°; obtaining a sampling point corresponding to the second motor rotor angle in the second current parameter sampling sequence, and using the sampling point as a second diagnostic point; The first phase current value corresponding to the first diagnostic point is used as a first phase current diagnostic parameter, and the second phase current value corresponding to the second diagnostic point is used as a second phase current diagnostic parameter.

3. The phase delay diagnosis method according to claim 2, characterized in that: Taking any sampling point in the first current parameter sampling sequence as a first diagnostic point includes: Taking the current sampling point in the first current parameter sampling sequence as the first diagnostic point; and / or, Obtaining a second motor rotor angle whose absolute value of difference from the first motor rotor angle is 120°, comprising: A second electronic rotor angle that is 120° before the first motor rotor angle is obtained.

4. The phase delay diagnosis method according to claim 2, characterized in that: If the deviation between the first phase current diagnostic parameter and the second phase current diagnostic parameter exceeds a preset phase delay error, then there is a phase delay between the two phase currents to be diagnosed, including: It is determined whether the absolute value of the difference between the first phase current value and the second phase current value is less than a preset current delay error value; if not, a phase delay exists between the two phase currents to be diagnosed.

5. The phase delay diagnosis method according to claim 1, wherein: Also includes: It is determined whether the motor is in a torque mutation state. If so, the phase delay diagnosis is not enabled.

6. The phase delay diagnosis method according to claim 1, characterized in that: Also includes: It is determined whether the duration of the phase delay between the two phase currents to be diagnosed exceeds a preset phase delay duration. If so, a phase delay diagnosis fault is reported.

7. The phase delay diagnosis method according to claim 1, characterized in that: The determining, according to a preset phase delay diagnosis rule, a first phase current diagnostic parameter corresponding to the first current parameter sampling sequence and a second phase current diagnostic parameter corresponding to the second current parameter sampling sequence includes: In the same electrical cycle, obtaining a first maximum current value or a first minimum current value in the first current parameter sampling sequence and a second maximum current value or a second minimum current value in the second current parameter sampling sequence; respectively obtaining a first phase angle corresponding to a sampling moment of the first maximum current value, a second phase angle corresponding to a sampling moment of the first minimum current value, a third phase angle corresponding to a sampling moment of the second maximum current value, and a fourth phase angle corresponding to a sampling moment of the second minimum current value; The first phase angle is used as the first phase current diagnostic parameter, and the third phase angle is used as the second phase current diagnostic parameter; or the second phase angle is used as the first phase current diagnostic parameter, and the fourth phase angle is used as the second phase current diagnostic parameter.

8. The phase delay diagnosis method according to claim 7, characterized in that: If the deviation between the first phase current diagnostic parameter and the second phase current diagnostic parameter exceeds a preset phase delay error, then there is a phase delay between the two phase currents to be diagnosed, including: determining whether the absolute value of the difference between the first phase angle and the third phase angle is greater than a preset upper limit of the phase angle deviation or less than a preset lower limit of the phase angle deviation; if so, a phase delay exists between the two phase currents to be diagnosed; or Determine whether the absolute value of the difference between the second phase angle and the fourth phase angle is greater than a preset upper limit value of the phase angle deviation or less than a preset lower limit value of the phase angle deviation. If so, there is a phase delay in the two phase currents to be diagnosed.

9. A motor control system for an electric vehicle, characterized in that: The motor control system includes an inverter, a motor, and a phase delay diagnostic device, wherein the phase delay diagnostic device includes a sampling unit, a diagnostic information acquisition unit, and a diagnostic execution unit; The inverter is configured to convert the direct current of the power supply battery into controllable three-phase alternating current to drive the motor; The sampling unit is configured to sample at least two phase currents to be diagnosed of the motor in each electrical cycle to obtain a first current value sampling sequence and a second current value sampling sequence; The diagnostic information acquisition unit is configured to determine a first phase current diagnostic parameter corresponding to the first current parameter sampling sequence and a second phase current diagnostic parameter corresponding to the second current parameter sampling sequence according to a preset phase delay diagnostic rule; The diagnosis execution unit is configured to determine that there is a phase delay between the two phase currents to be diagnosed if a deviation between the first phase current diagnosis parameter and the second phase current diagnosis parameter exceeds a preset phase delay error.

10. An electronic device, characterized in that: The method comprises a processor and a memory, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the method for diagnosing the phase delay of the motor phase current according to any one of claims 1 to 8 is implemented.

11. A readable storage medium, characterized in that: The readable storage medium stores a computer program, and when the computer program is executed by a processor, the method for diagnosing phase delay of a motor phase current according to any one of claims 1 to 8 is implemented.

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