Fault-tolerant control method based on single-phase current sensor and electronic equipment

Abstract

The invention relates to the field of motor control, in particular to a fault-tolerant control method based on a single-phase current sensor, electronic equipment for implementing the method and a computer storage medium. The method comprises the following steps: obtaining a first phase current feedback value collected by a current sensor of a first phase in response to determining that the first phase of the AC motor does not have a current sensor fault and other phases are fault phases with the current sensor fault; setting a second phase current feedback value of a second phase in the fault phase as an opposite number of the first phase current feedback value, and setting inverter bridge arm switch tubes of other phases in the fault phase in a turn-off state; and performing vector control on the AC motor based on the first phase current feedback value, the second phase current feedback value and a preset current reference value.

Description

Technical Field

[0001] The present application relates to the field of motor control, and more specifically to a fault-tolerant control method based on a single-phase current sensor, an electronic device for implementing the method, and a computer storage medium. Background Art

[0002] In the field of electric vehicles, for models with front and rear dual electric drive configurations, even if one electric drive system fails, the vehicle can still rely on the other electric drive system to maintain normal driving functions. However, this method cannot be applied to single-electric drive models, which puts more stringent requirements on the stability and fault tolerance of single-electric drive systems. In particular, vector control, as the core technology in the electric drive system, its control process is highly dependent on the phase current information collected by the current sensor. Once the current sensor fails, it will directly affect the accuracy of vector control and the stability of the system.

[0003] To deal with current sensor failures in electric drive systems, a common practice is to implement sensor redundancy design. In a typical three-phase AC electric drive architecture, three independent phase current sensors are configured to ensure system reliability and fault tolerance. When one of the sensors fails, the system can quickly switch to a mode that relies on the remaining two healthy sensors to maintain vector control functions. However, in the face of more complex situations, when two phase current sensors fail at the same time, traditional redundancy strategies are unable to cope with the situation.

[0004] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present application, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0005] In order to solve or at least alleviate one or more of the above problems, the present application provides a fault-tolerant control method based on a single-phase current sensor, an electronic device implementing the method, and a computer storage medium, which can ensure that the AC motor can operate normally when only one phase of healthy current sensor is left, thereby avoiding the occurrence of stalling.

[0006] According to a first aspect of the present application, a fault-tolerant control method based on a single-phase current sensor is provided, the method comprising the following steps: in response to determining that the first phase of the AC motor has not had a current sensor failure and the remaining phases are all faulty phases with current sensor failures, obtaining a first-phase current feedback value collected by the current sensor of the first phase; setting a second-phase current feedback value of the second phase in the faulty phase to the opposite of the first-phase current feedback value, and placing the inverter bridge arm switches of the remaining phases in the faulty phase in an off state; and performing vector control on the AC motor based on the first-phase current feedback value, the second-phase current feedback value, and a preset current reference value.

[0007] As an alternative or supplement to the above solution, in a fault-tolerant control method according to an embodiment of the present application, the second phase is determined based on the following steps: randomly selecting a phase from each faulty phase as the second phase.

[0008] As an alternative or supplement to the above scheme, the fault-tolerant control method according to an embodiment of the present application also includes: when the vehicle speed or the motor speed is zero and the motor torque is lower than the vehicle starting torque, reselecting a phase from each faulty phase as the second phase, wherein the reselected second phase is different from the originally selected second phase.

[0009] As an alternative or supplement to the above scheme, in a fault-tolerant control method according to an embodiment of the present application, the second phase is determined based on the following steps: when the vehicle speed or the motor speed is zero, obtaining the current motor rotor electrical angle; and based on the current motor rotor electrical angle, selecting one phase from each faulty phase as the second phase.

[0010] As an alternative or supplement to the above scheme, in a fault-tolerant control method according to an embodiment of the present application, selecting a phase from each fault phase as the second phase according to the current motor rotor electrical angle includes: for each of the fault phases, determining the motor torque that the AC motor is expected to output at the current motor rotor electrical angle when the phase is selected as the second phase; and selecting the phase with the largest expected output motor torque as the second phase.

[0011] As an alternative or supplement to the above scheme, in a fault-tolerant control method according to an embodiment of the present application, selecting a phase from each fault phase as the second phase according to the current motor rotor electrical angle includes: for each of the fault phases, determining the motor torque that the AC motor is expected to output at the current motor rotor electrical angle when the phase is selected as the second phase; determining the fault phase whose expected output motor torque is greater than the vehicle starting torque; and randomly selecting a phase from the fault phase whose expected output motor torque is greater than the vehicle starting torque as the second phase.

[0012] As an alternative or supplement to the above scheme, in a fault-tolerant control method according to an embodiment of the present application, the current reference value is set to a quadrature-axis current reference value and a direct-axis current reference value determined when the first phase and the second phase operate normally.

[0013] As an alternative or supplement to the above solution, in a fault-tolerant control method according to an embodiment of the present application, when the AC motor is a permanent magnet synchronous motor and the inverter is a three-phase full-bridge inverter, the quadrature-axis current reference value i qref and the direct axis current reference value i dref Satisfies the following equation:

[0014]

[0015] Among them, θ e is the electrical angle of the motor rotor, θ1 is a preset value and depends on the fault phase that is placed in the off state, J is the objective function, T qref is the motor torque reference value, N p is the number of motor pole pairs, λ m is the permanent magnet flux, L d is the direct-axis inductance, L q is the quadrature-axis inductance.

[0016] As an alternative or supplement to the above solution, in a fault-tolerant control method according to an embodiment of the present application, when performing vector control, the current feedback value of the fault phase other than the second phase is set to zero.

[0017] According to the second aspect of the present application, an electronic device is provided, comprising: a memory; a processor; and a computer program stored on the memory and executable on the processor, wherein the execution of the computer program enables any one of the fault-tolerant control methods described in the first aspect of the present application to be executed.

[0018] As an alternative or supplement to the above solution, the electronic device according to an embodiment of the present application is a vehicle.

[0019] According to a third aspect of the present invention, a computer storage medium is provided, the computer storage medium comprising instructions, the instructions executing any one of the fault-tolerant control methods according to the first aspect of the present invention when run.

[0020] The fault-tolerant control scheme according to one or more embodiments of the present application can solve the problem that a multi-phase AC motor control system cannot continue to operate when only one phase of healthy current sensor is left, thereby improving the reliability of the AC motor control system when facing extreme situations. In addition, the scheme does not require the introduction of additional hardware equipment, greatly reducing the implementation cost and maintenance difficulty. At the same time, the scheme abandons the traditional redundant observer technology and avoids the loss of accuracy and computational complexity that may be introduced due to the reconstruction of phase currents. On the contrary, the present scheme directly utilizes the real-time data of a single-phase healthy current sensor and realizes precise regulation of the motor state through vector control, ensuring that the motor can maintain a stable and controllable operating state even under sensor failure conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and / or other aspects and advantages of the present application will become clearer and easier to understand through the following description of various aspects in conjunction with the accompanying drawings, in which the same or similar units are represented by the same reference numerals. In the accompanying drawings:

[0022] Figure 1 is a schematic flow chart of a fault-tolerant control method 10 according to one or more embodiments of the present application;

[0023] Figure 2 A topological circuit diagram of a three-phase permanent magnet synchronous motor and a three-phase full-bridge inverter according to one or more embodiments of the present application;

[0024] Figure 3 It is a schematic waveform diagram of the d-axis and q-axis current reference values ​​determined when the A-phase and the B-phase are in operation and the C-phase bridge arm switch tube is blocked;

[0025] Figure 4 is a schematic waveform diagram of the motor torque expected to be output under vector control;

[0026] Figure 5 A schematic comparison diagram of the motor torque expected to be output when different phases are sealed;

[0027] Figure 6 is a schematic flow chart of a fault-tolerant control method 60 according to one or more embodiments of the present application;

[0028] Figure 7 is a schematic block diagram of an electronic device 70 according to one or more embodiments of the present application. DETAILED DESCRIPTION

[0029] The description of the following specific embodiments is merely exemplary in nature and is not intended to limit the disclosed technology or the application and use of the disclosed technology. In addition, it is not intended to be bound by any express or implied theory presented in the aforementioned technical field, background technology or the following specific embodiments.

[0030] In the following detailed description of the embodiments, many specific details are set forth in order to provide a more thorough understanding of the disclosed technology. However, it is apparent to one of ordinary skill in the art that the disclosed technology can be practiced without these specific details. In other instances, well-known features are not described in detail to avoid unnecessarily complicating the description.

[0031] Terms such as "comprising" and "including" indicate that in addition to the units and steps directly and clearly stated in the specification, the technical solution of the present application does not exclude the situation of having other units and steps that are not directly or clearly stated. Terms such as "first" and "second" do not indicate the order of units in terms of time, space, size, etc., but are only used to distinguish between units.

[0032] Hereinafter, various exemplary embodiments according to the present application will be described in detail with reference to the accompanying drawings.

[0033] Referring to the accompanying drawings, Figure 1 FIG. 1 is a schematic flow chart of a fault-tolerant control method 10 according to one or more embodiments of the present application. The fault-tolerant control method 10 may be applicable to a motor control system for a synchronous motor such as a permanent magnet synchronous motor, a synchronous reluctance motor, or an asynchronous motor.

[0034] like Figure 1 As shown, in step S110, in response to determining that the first phase of the AC motor has no current sensor failure and the remaining phases are faulty phases with current sensor failures, a first phase current feedback value collected by the current sensor of the first phase is obtained.

[0035] As mentioned above, vector control is the core technology of motor control, and its control process is highly dependent on the phase current information collected by the current sensor (that is, the "phase current feedback value"). Once the current sensor fails, it will directly affect the accuracy of the vector control and the stability of the system. In the design of the electric drive system, the current sensor is usually set at the output end of the AC motor inverter, close to the connection of the motor winding. Under the standard configuration, a phase current sensor is set at the output end of each phase bridge arm of the inverter of the M-phase AC motor (M is a positive integer greater than or equal to 3) phase AC motor, so as to improve the reliability and fault tolerance of the system through redundant design, and ensure that the system can still maintain its operating capacity when individual current sensors fail. It should be noted that, since the method 10 of the present application can realize fault-tolerant control when only one phase of healthy current sensor is left, the scheme is applicable to the scenario where only 1 to M-1 phase current sensors are set in the electric drive system. Therefore, the method 10 of the present application not only improves the emergency operation capability of the electric drive system in the face of current sensor failure, but also reduces the dependence on the number of current sensors, thereby ensuring system reliability while optimizing cost-effectiveness.

[0036] As shown in step S110, the triggering condition of the fault-tolerant control method 10 is that the system has determined that "the first phase of the AC motor has no current sensor failure, and the remaining phases are all faulty phases with current sensor failures." That is, the fault-tolerant control method 10 is executed when it has been determined through a certain fault detection mechanism that only one phase of healthy current sensor remains. Exemplarily, the above-mentioned fault detection mechanism can be implemented in the following ways: 1) Regular self-check: The system can regularly perform self-checks on each current sensor, and judge whether each current sensor is in a normal working state by comparing the sensor feedback value with the preset reference value; 2) Cross-check: If there are redundant current sensors in the system (for example, three phase current sensors are set in a three-phase AC electric drive system), redundancy can be used for cross-checking, for example, whether the sum of the current feedback values ​​of each phase is zero to judge whether there is a current sensor failure; 3) Intelligent algorithm analysis: The feedback value of the current sensor is analyzed using an intelligent algorithm to identify abnormal patterns or trends, and to warn of potential fault risks in advance. It should be noted that the fault detection mechanism for the current sensor can be based on a detection mechanism known in the art, and this application does not make specific limitations on this.

[0037] In order to distinguish the only healthy phase in the AC motor (i.e., the phase corresponding to the current sensor without fault) from the faulty phase (i.e., the phase corresponding to the current sensor with fault), the healthy phase is referred to as the "first phase" in this article. Accordingly, the current information collected by the only fault-free current sensor is referred to as the "first phase current feedback value".

[0038] In step S120, the second phase current feedback value of the second phase in the faulty phase is set to the opposite number of the first phase current feedback value, and the inverter bridge arm switches of the remaining phases in the faulty phase are placed in an off state.

[0039] It is understandable that the vector control of an M-phase AC motor requires at least two phases of current information as input for closed-loop control. However, in extreme cases (i.e., only one phase of healthy current sensor remains), only one phase of current information can be used directly for vector control. In view of this, the present application proposes to select one phase from all faulty phases as the control phase for subsequent vector control (in order to distinguish it from the "first phase" as a healthy phase, this control phase is referred to as the "second phase" in this article) to replace the missing current information. The core of this strategy is to use the current feedback value of the healthy phase (i.e., the "first phase") to indirectly estimate the current state of the second phase.

[0040] During the specific implementation, the inverter bridge arm switches of all faulty phases except the second phase are first placed in the off state (i.e., a wave-blocking operation is performed) to ensure that the current contribution of these phases is zero, thereby simplifying the current analysis. Subsequently, the second-phase current feedback value is directly set to the opposite of the first-phase current feedback value. Based on the above-mentioned wave-blocking operation, the second-phase current feedback value is equal in magnitude and opposite in direction to the first-phase current feedback value. The above strategy aims to utilize limited healthy sensor information to simulate the missing phase current information, thereby ensuring the stable operation of vector control under extreme conditions. This strategy not only simplifies the fault handling process, but also improves the robustness and reliability of the system.

[0041] Several possible implementations of how to select one phase from all faulty phases as the control phase (ie, the “second phase”) for subsequent vector control are described below.

[0042] In one possible implementation, a phase is randomly selected from each faulty phase as the second phase. The advantage of this method is that it is simple and easy to implement, but since the randomly selected second phase may not be suitable for the current operating state of the motor, in the scenario where the current motor speed is 0 or the vehicle speed is 0, the problem of being unable to start normally due to too low output torque may occur. In this regard, the following reselection mechanism can be introduced-if the current motor speed is 0 or the vehicle speed is 0, and the vehicle does not start normally after the second phase is randomly selected (that is, corresponding to the situation where the motor torque is lower than the vehicle starting torque), a phase can be reselected from the remaining faulty phases as the second phase, and the reselected second phase should be different from the originally selected second phase. The reselection mechanism ensures that if the vehicle does not start normally, there is an opportunity to optimize the operating state of the motor by replacing the second phase, thereby improving the successful start rate of the vehicle. Optionally, the above reselection operation can be repeated until the vehicle starts normally.

[0043] In another possible implementation, in a scenario where the current motor speed is 0 or the vehicle speed is 0, the real-time operating status of the motor, especially the current motor rotor electrical angle, can be used as the basis for selecting the second phase. This method aims to improve the operating efficiency and starting capability of the motor under fault conditions through more precise selection. For example, when the motor speed is 0 or the vehicle speed is 0, the current motor rotor electrical angle is first obtained; then, each fault phase is evaluated based on the current motor rotor electrical angle to determine the motor torque that the AC motor can be expected to output at the current motor rotor electrical angle when the phase is selected as the second phase.

[0044] In one example, the second phase can be selected based on the strategy of maximizing the expected torque. Specifically, the fault phase that can produce the maximum expected output motor torque is directly selected as the second phase. The strategy of maximizing the expected torque can ensure that when the motor is started or running at low speed, sufficient torque output is provided as much as possible, thereby improving the success rate of starting. In another example, the second phase can be selected based on the starting torque threshold strategy. Unlike the strategy of maximizing the expected torque, this method first screens out those fault phases whose expected output motor torque is greater than the minimum torque required for vehicle starting (ie, "vehicle starting torque"), and then randomly selects a phase from these qualified fault phases as the second phase. The starting torque threshold strategy ensures that the motor can output enough torque to start the vehicle while retaining a certain degree of selection flexibility.

[0045] The above-mentioned expected output motor torque can be determined by theoretical calculation according to the motor torque formula, or can be obtained by simulation or experiment. For example, when the AC motor is a permanent magnet synchronous motor and the inverter is a three-phase full-bridge inverter, the expected output motor torque T can be calculated using the following formula: q :

[0046]

[0047] Among them, N p is the number of motor pole pairs, λ m is the permanent magnet flux, L d is the direct-axis inductance, L q is the quadrature-axis inductance, i qref is the q-axis current reference value and i dref is the d-axis current reference value. qref and i dref The specific settings will be introduced in detail below.

[0048] In step S130 , vector control is performed on the AC motor based on the first phase current feedback value, the second phase current feedback value, and a preset current reference value.

[0049] Vector control is a complex motor control technology that aims to control the motor torque and speed by changing the phase and amplitude of the motor stator current. The vector control includes at least the following three input information: 1) First phase current feedback value: It is the current value directly measured from one phase winding of the motor using the only healthy current sensor, reflecting the actual working condition of the motor in the healthy phase; 2) Second phase current feedback value: As shown in step 120, it is the current state of the second phase indirectly estimated using the current feedback value of the healthy phase, that is, the opposite of the first phase current feedback value; 3) Preset current reference value: It is a current value pre-set according to the control target and current working state of the motor, used to guide the operation of the motor. In vector control, in order to simplify the control problem, the input current feedback value (that is, the first phase current feedback value and the second phase current feedback value) is usually transformed into a two-phase rotating coordinate system (that is, dq coordinate system). The vector control algorithm calculates the control error by comparing the current feedback value with the preset current reference value, and adjusts the control input of the motor (for example, voltage, frequency, etc.) based on the error to reduce the error and make the actual current of the motor as close as possible to the preset current reference value.

[0050] Exemplarily, the preset current reference value can be fixed or dynamically adjusted, depending on the requirements of the control algorithm. In one possible implementation, the current reference value is set to the quadrature axis (q-axis) current reference value and the direct axis (d-axis) current reference value determined when the first phase and the second phase are operating normally. For example, when the AC motor is a three-phase motor, and phase A is a healthy phase, and phases B and C are faulty phases, if phase B is selected as the second phase, the current reference value is set to the q-axis current reference value and the d-axis current reference value determined when phases A and B are operating normally; if phase C is selected as the second phase, the current reference value is set to the q-axis current reference value and the d-axis current reference value determined when phases A and C are operating normally.

[0051] The following example takes the scenario where two phases of a three-phase AC motor are operating normally and the other phase is blocked as an example. qref and d-axis current reference value i dref According to the above analysis, the current feedback value of the wave-closing phase is set to zero. In this case, i qref and i dref Satisfy the following formula:

[0052]

[0053] Among them, T qrefis the motor torque reference value, and J is the objective function, which aims to minimize the difference between the motor output torque and the motor torque reference value. By solving the above formula, the quadrature and direct axis current reference values ​​at different motor rotor electrical angles can be obtained.

[0054] Optionally, the motor may be vector controlled according to step S130 until the vehicle stops. If the system receives a restart instruction after the vehicle stops, the above steps S120-S130 are re-executed.

[0055] The following will take a three-phase permanent magnet synchronous motor and a three-phase full-bridge inverter as examples to introduce the fault-tolerant control scheme in detail. It should be noted that the fault-tolerant control scheme according to the present application can be applied to other types of AC motors (e.g., five-phase AC motors) based on the same or similar principles, and the examples and implementation methods shown should be regarded as illustrative rather than restrictive.

[0056] refer to Figure 2 , Figure 2 A topological circuit diagram of a three-phase permanent magnet synchronous motor and a three-phase full-bridge inverter according to one or more embodiments of the present application is shown.

[0057] like Figure 2 As shown, the three-phase full-bridge inverter includes three bridge arms, each of which can be divided into an upper bridge arm and a lower bridge arm, wherein each upper bridge arm and lower bridge arm each includes a switch tube and a diode. A1 , T A2 And diode D A1 , D A2 The B phase winding of the three-phase motor is connected to the switch tube T B1 , T B2 And diode D B1 , D B2 The C phase winding of the three-phase motor is connected to the switch tube T C1 , T C2 And diode D C1 , D C2 There are S near the A, B, and C phase windings. A , S B , S C Three current sensors.

[0058] Known current sensor S B , S C Failure occurs, S A No fault has occurred, so it is necessary to select one phase from phases B and C as the control phase (i.e., the "second phase"), and block the other corresponding inverter bridge arm switch tube. Assume that phase B has been selected as the second phase, and phase C has been blocked. Figure 2 As shown, the driving signal can be used toC1 , T C2 The C-phase winding is turned off so that it cannot be directly connected to the positive and negative poles of the power supply through the switch tube. Since the C-phase bridge arm switch tube is in the off state, when the motor is in normal electric operation mode and the reverse potential is less than the bus voltage, i C The B phase current feedback value i B Equal to the A phase current feedback value i A The opposite of i B =-i A Next, use i A and i B , and a preset current reference value to perform closed-loop vector control on the current. For example, four switch tube drive signals A1, A2, B1 and B2 can be output through space vector pulse width modulation (SVPWM) to control T A1 , T A2 , T B1 , T B2 Perform switching action.

[0059] Figure 3 A schematic waveform diagram of the d-axis and q-axis current reference values ​​determined when the A-phase and B-phase are running and the C-phase bridge arm switch tube is blocked is shown. Figure 4 FIG. 4 shows a schematic waveform diagram of the motor torque expected to be output under vector control. Figure 3 and Figure 4 As shown in the figure, since the C-phase bridge arm switch tube is blocked, the q-axis current reference value i qref and d-axis current reference value i dref There will be a drop in some rotor electrical angle areas, correspondingly, the expected output motor torque T q It will be appreciated that the specific drop region will vary depending on the selected second phase or closing phase.

[0060] Figure 5 FIG. 4 shows a schematic comparison diagram of the motor torque expected to be output when different phases are sealed. Figure 5 As shown in the figure, when the C phase is blocked and the B phase is selected as the second phase, T q It falls near θ1 and θ2; when the B phase is blocked and the C phase is selected as the second phase, T q It falls around θ3 and θ4. In this regard, the maximum expected torque strategy or the starting torque threshold strategy discussed above can be referred to, and one phase is selected from phases B and C as the second phase based on the current motor rotor electrical angle.

[0061] Figure 6 is a schematic flow chart of a fault-tolerant control method 60 according to one or more embodiments of the present application.

[0062] like Figure 6 As shown, in step S610, when it is determined that the first phase of the AC motor has no current sensor fault and the remaining phases are faulty phases with current sensor faults, the fault-tolerant control strategy is enabled.

[0063] In step S620, a first-phase current feedback value collected by a first-phase current sensor is obtained.

[0064] In step S630, one phase is selected from each faulty phase as the second phase, and the second phase current feedback value is set to the opposite number of the first phase current feedback value.

[0065] In step S640, the inverter bridge arm switches of the remaining faulty phases are placed in an off state.

[0066] In step S650, vector control is performed on the AC motor based on the first phase current feedback value, the second phase current feedback value, and a preset current reference value until the vehicle stops.

[0067] In step S660, it is determined whether a restart instruction is received. If a restart instruction is received, steps S620-S660 are continued. If no restart instruction is received, the process ends.

[0068] The above-mentioned fault-tolerant control methods 10 and 60 can solve the problem that a multi-phase AC motor control system cannot continue to operate when only one phase of healthy current sensor is left, thereby improving the reliability of the AC motor control system when facing extreme situations. In addition, the fault-tolerant control methods 10 and 60 do not require the introduction of additional hardware equipment, which greatly reduces the implementation cost and maintenance difficulty. At the same time, the fault-tolerant control methods 10 and 60 abandon the traditional redundant observer technology, avoiding the accuracy loss and computational complexity that may be introduced due to the reconstruction of phase current. On the contrary, the fault-tolerant control methods 10 and 60 directly use the real-time data of a single-phase healthy current sensor, and realize the precise regulation of the motor state through vector control, ensuring that the motor can maintain a stable and controllable operating state even under sensor failure conditions.

[0069] Figure 7 7 is a schematic block diagram of an electronic device 70 according to one or more embodiments of the present application. The electronic device 70 includes a memory 710, a processor 720, and a computer program 730 stored in the memory 710 and executable on the processor 720. The execution of the computer program 730 enables the above-mentioned fault-tolerant control method 10 or 60 to be executed. Exemplarily, the electronic device 30 may be a motor control system or a drive module in a motor control system, or a vehicle.

[0070] In addition, the present application can also be implemented as a computer storage medium, in which a program for causing a computer to execute the above-mentioned fault-tolerant control method 10 or 60 is stored. Here, as the computer storage medium, various computer storage media such as disks (e.g., magnetic disks, optical disks, etc.), cards (e.g., memory cards, optical cards, etc.), semiconductor memories (e.g., ROMs, non-volatile memories, etc.), and tapes (e.g., magnetic tapes, cassette tapes, etc.) can be used.

[0071] In the applicable situation, hardware, software or a combination of hardware and software can be used to realize the various embodiments provided by the application. Moreover, in the applicable situation, without departing from the scope of the application, the various hardware components and / or software components set forth herein can be combined into a composite component comprising software, hardware and / or both. In the applicable situation, without departing from the scope of the application, the various hardware components and / or software components set forth herein can be divided into subcomponents comprising software, hardware or both. In addition, in the applicable situation, it is contemplated that the software component can be implemented as a hardware component, and vice versa.

[0072] Software (such as program code and / or data) according to the present application can be stored on one or more computer storage media. It is also contemplated that the software identified herein can be implemented using one or more general or special-purpose computers and / or computer systems, networked and / or otherwise. Where applicable, the order of the various steps described herein can be changed, combined into composite steps, and / or divided into sub-steps to provide the features described herein.

[0073] The embodiments and examples set forth herein are provided to best illustrate embodiments according to the present application and its specific applications, and thereby enable those skilled in the art to implement and use the present application. However, those skilled in the art will appreciate that the above description and examples are provided only for ease of illustration and example. The description set forth is not intended to cover all aspects of the present application or to limit the present application to the precise form disclosed.

Claims

1. A fault-tolerant control method based on a single-phase current sensor, characterized in that: The method comprises the following steps: In response to determining that the first phase of the AC motor has no current sensor failure and the remaining phases are faulty phases with current sensor failures, obtaining a first phase current feedback value collected by the current sensor of the first phase; Setting a second phase current feedback value of a second phase in the faulty phase to the opposite number of the first phase current feedback value, and placing inverter bridge arm switches of the remaining phases in the faulty phase in an off state; and Vector control is performed on the AC motor based on the first phase current feedback value, the second phase current feedback value, and a preset current reference value.

2. The fault-tolerant control method according to claim 1, characterized in that: The second phase is determined based on the following steps: A phase is randomly selected from each faulty phase as the second phase.

3. The fault-tolerant control method according to claim 1 or 2, characterized in that: The method further comprises: When the vehicle speed or the motor speed is zero and the motor torque is lower than the vehicle starting torque, a phase is reselected from each faulty phase as the second phase, wherein the reselected second phase is different from the originally selected second phase.

4. The fault-tolerant control method according to claim 1, characterized in that: The second phase is determined based on the following steps: When the vehicle speed or the motor speed is zero, obtaining the current motor rotor electrical angle; and According to the current electrical angle of the motor rotor, one phase is selected from each faulty phase as the second phase.

5. The fault-tolerant control method according to claim 4, characterized in that: According to the current electrical angle of the motor rotor, selecting one phase from each faulty phase as the second phase comprises: For each of the faulty phases, determining the motor torque that the AC motor is expected to output at the current motor rotor electrical angle when the phase is selected as the second phase; and The phase with the largest motor torque expected to be output is selected as the second phase.

6. The fault-tolerant control method according to claim 4, characterized in that: According to the current electrical angle of the motor rotor, selecting one phase from each faulty phase as the second phase comprises: For each of the faulty phases, determining the motor torque that the AC motor is expected to output at the current motor rotor electrical angle when the phase is selected as the second phase; Determine a fault phase in which the motor torque expected to be output is greater than the vehicle starting torque; and A phase is randomly selected from the fault phases whose expected output motor torque is greater than the vehicle starting torque as the second phase.

7. The fault-tolerant control method according to claim 1, characterized in that: The current reference value is set to a quadrature-axis current reference value and a direct-axis current reference value determined when the first phase and the second phase operate normally.

8. The fault-tolerant control method according to claim 7, characterized in that: When the AC motor is a permanent magnet synchronous motor and the inverter is a three-phase full-bridge inverter, the quadrature-axis current reference value i qref and the direct axis current reference value i dref Satisfies the following equation: Among them, θ e is the electrical angle of the motor rotor, θ1 is a preset value and depends on the fault phase that is placed in the off state, J is the objective function, T qref is the motor torque reference value, N p is the number of motor pole pairs, λ m is the permanent magnet flux, L d is the direct-axis inductance, L q is the quadrature-axis inductance.

9. The fault-tolerant control method according to claim 1, characterized in that: When vector control is performed, current feedback values ​​of fault phases other than the second phase are set to zero.

10. An electronic device, characterized in that: The method comprises: a memory; a processor; and a computer program stored in the memory and executable on the processor, wherein the execution of the computer program enables the fault-tolerant control method according to any one of claims 1 to 9 to be executed.

11. The electronic device according to claim 10, characterized in that: The electronic device is a vehicle.

12. A computer-readable storage medium, characterized in that: The computer-readable storage medium comprises instructions, which, when executed, execute the fault-tolerant control method according to any one of claims 1 to 9.

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