Electric vehicle open-phase fault operation control method, vehicle controller and electric vehicle

Abstract

The invention discloses an electric vehicle open-phase fault operation control method, a vehicle controller and an electric vehicle, relates to the field of new energy automobiles, and can be applied to pure electric vehicles and hybrid vehicles. The control method is used for achieving entering and exiting of a limp mode through interaction with a driver and passengers after a power assembly of the electric vehicle has an open-phase fault, and the control method comprises the steps that after the power assembly has the open-phase fault, fault prompt information is output, and the electric vehicle is controlled to limp. The fault prompt information is used for indicating that the power assembly has an open-phase fault, the open-phase fault comprises an open circuit of any phase of bridge arm of the motor controller, and the motor controller outputs two-phase alternating current to the driving motor in the limping process to drive the electric vehicle to run. And in the limping process of the electric vehicle, after limping ending information input by a driver and passengers is received, the motor controller is controlled to enter an active short-circuit state or an output closing state so that the electric vehicle can be stopped. According to the scheme, the safety and experience of the vehicle are improved.

Description

Technical Field

[0001] The present application relates to the field of electric vehicles, and more particularly, to a method for controlling operation of an electric vehicle with a phase loss fault, a vehicle controller, and an electric vehicle. Background Art

[0002] With the development of the automotive industry, the number of vehicles is increasing year by year. As a key component of electric vehicles, the safety and reliability of the drive system are crucial to the driver's property and life safety. Permanent magnet synchronous motors (PMSMs), with their advantages such as high efficiency, high power density, and fast torque response, have become the primary development trend for drive motors in electric vehicles. For electric vehicles using PMSMs as their sole drive source, a phase loss in one of the three phases of the PMSM, caused by a driver chip failure, power module failure, or phase line disconnection, can easily lead to a vehicle breakdown due to a loss of power output from the drive motor, potentially causing a safety accident. Therefore, electric vehicles enter limp home mode after a phase loss failure. In limp home mode, the vehicle's power is limited, restricting driver control and significantly reducing comfort. Vibration, jolts, or noise may occur, which can easily cause panic among drivers and passengers and affect driving safety.

[0003] Therefore, how to improve the driver and passengers' control over the limp home mode after a phase failure occurs in an electric vehicle is a problem that needs to be solved. Summary of the Invention

[0004] The present application provides an electric vehicle phase loss fault operation control method, a vehicle controller and an electric vehicle. When a phase loss fault occurs in the electric vehicle drive motor, the electric vehicle enters a limp home mode, and achieves safe parking and other operations with a controllable limited torque. The driver controls the timing of exiting the limp home mode, and the electric vehicle interacts with the driver in a timely manner to synchronize fault information and phase loss limp home constraint information, thereby improving the safety of the vehicle.

[0005] In a first aspect, the present application provides a method for controlling the operation of an electric vehicle in the event of a phase loss fault. The control method is used to achieve entry and exit of limp home mode through interaction with the driver and passengers after a phase loss fault occurs in the powertrain of the electric vehicle. The control method includes, during the driving process of the electric vehicle, before the phase loss fault occurs in the powertrain, controlling the motor controller of the electric vehicle to output three-phase AC power to the drive motor to drive the electric vehicle. After the phase loss fault occurs in the powertrain, a fault prompt message is output and the electric vehicle is controlled to limp home. The fault prompt message is used to indicate that a phase loss fault has occurred in the powertrain. The phase loss fault includes an open circuit in any one-phase bridge arm of the motor controller. During the limp home process of the electric vehicle, the motor controller outputs two-phase AC power to the drive motor to drive the electric vehicle. During the limp home process of the electric vehicle, after receiving the limp home end information input by the driver and passengers, the motor controller is controlled to enter an active short-circuit state or an output-off state to stop the electric vehicle.

[0006] In the event of a serious powertrain failure or risk, an electric vehicle's powertrain torque output is limited to protect the vehicle's hardware. If the vehicle stalls due to a lack of power output, this could easily lead to an accident and affect the safety of the driver and passengers. Therefore, the vehicle is controlled to enter limp home mode. Limp home mode allows the vehicle to continue driving even in the event of a powertrain failure. While the powertrain's torque output is limited, the vehicle can still maintain driving. Limp home mode is also known as limp home mode, safety mode, or protection mode.

[0007] A phase loss fault in the powertrain refers to an open circuit in any phase of the three-phase bridge arm of the motor controller, or an open circuit in any phase of the three-phase winding of the drive motor. Phase loss faults include driver chip faults, current sensor faults, and module faults. Driver chip faults include internal communication faults in the driver chip, dead zone faults, cyclic redundancy check (CRC) configuration faults, self-test failures, and overcurrent. Current sensor faults include effective value overcurrent, hardware overcurrent, zero drift anomalies, and current verification faults. Module faults include module overtemperature and diode overtemperature. When a phase loss fault occurs in the powertrain, one phase of the powertrain is open circuited, while the other two phases are normal and controllable.

[0008] Before a powertrain phase loss fault occurs, the electric vehicle is in normal operating mode, and the electric vehicle's motor controller outputs three-phase AC power to the drive motor to drive the electric vehicle. After a powertrain phase loss fault occurs, the electric vehicle enters limp home mode, and the motor controller outputs two-phase AC power to the drive motor to drive the electric vehicle. When the electric vehicle enters limp home mode, in order to ensure basic mobility while avoiding further damage to core components such as the three-electric system, the electric vehicle's operating status will be significantly and strictly restricted. At this time, it is necessary to promptly remind the driver and passengers of the powertrain failure and output a fault prompt message. The fault prompt message is used to indicate that a powertrain phase loss fault has occurred. The fault prompt message is output through the electric vehicle's screen, such as the central control screen or instrument panel screen, or through the electric vehicle's voice system. The purpose of the fault prompt message is to promptly and clearly remind the driver and passengers of the powertrain failure, so that the driver and passengers can prepare for entering limp home mode.

[0009] During limp home mode, the driver or passenger can choose to end limp home mode at any time. After entering the limp home end signal, the motor controller is controlled to enter an active short-circuit state or shut down the output to stop the EV. If the driver or passenger chooses to exit limp home mode safely, the EV will lose power, allowing the driver or passenger to prepare for parking.

[0010] According to the solution of the present application, when a phase loss fault occurs in the drive motor of an electric vehicle, the electric vehicle enters the limp home mode. The electric vehicle interacts with the driver in a timely manner to synchronize fault information, and the driver decides the timing to exit the limp home mode. The controllable limp home mode is used to achieve safe parking and other operations, thereby improving the safety of the vehicle and the controllability of the driver and passengers.

[0011] In combination with the first aspect, in certain implementations of the first aspect, the control method further includes outputting limp home prompt information after controlling the electric vehicle to limp home after a phase loss fault occurs in the powertrain, wherein the limp home prompt information is used to instruct the electric vehicle to enter limp home mode.

[0012] When an electric vehicle enters limp home mode, its operating state is significantly and strictly restricted to ensure basic mobility while preventing further damage to core components, such as the three-electric system. This significantly reduces the vehicle's power and comfort. The powertrain's output capacity is limited, for example, the response speed of the powertrain's torque output decreases with accelerator pedal opening. Comfort is also limited, for example, there may be a jerking sensation and loud noise when the powertrain outputs torque. Without a warning, these limited capabilities and the sudden change in the vehicle's comfort can cause driver and passenger anxiety. Therefore, a limp home warning message is displayed after the electric vehicle enters limp home mode. This limp home warning message indicates that the electric vehicle has entered limp home mode. The limp home warning message is displayed on the electric vehicle's screen, such as the central control screen or instrument panel, or through the electric vehicle's voice system. The purpose of the limp home warning message is to promptly and clearly inform the driver and passengers that the electric vehicle has entered limp home mode, thereby alleviating any anxiety caused by the vehicle's changes.

[0013] According to the solution of the present application, when a phase loss fault occurs in the drive motor of an electric vehicle, the electric vehicle enters limp mode. The electric vehicle interacts with the driver in a timely manner and synchronizes the limp mode entry information, thereby reducing the tension of the driver and passengers caused by the changes in the electric vehicle, avoiding misoperation caused by tension that may cause the vehicle to lose control, and improving the safety of the vehicle.

[0014] In combination with the first aspect, in certain implementations of the first aspect, the control method specifically includes outputting limp state information through voice broadcast of the electric vehicle at preset time intervals during the limp state of the electric vehicle, wherein the limp state information is used to indicate that the electric vehicle is in limp mode.

[0015] When an electric vehicle enters limp home mode, in order to ensure basic mobility, the operating status of the electric vehicle will be significantly and strictly restricted. The power and comfort of the electric vehicle will be significantly reduced. The driver and passengers may not notice the limp home prompt information. The limited ability and sudden changes in the comfort of the electric vehicle will cause the driver and passengers to be nervous. Therefore, during the limp home process of the electric vehicle, the limp home status information is output through the electric vehicle's screen, such as the central control screen or instrument panel screen, or is output regularly through the electric vehicle's voice system. The purpose of the limp home status information is to continuously remind the driver and passengers that the electric vehicle is in limp home mode and reduce the tension caused by the changes in the electric vehicle. At the same time, in order to avoid too frequent reminders affecting the driver's attention, set a time interval and give reminders at the preset time interval.

[0016] According to the solution of the present application, when a phase loss fault occurs in the electric vehicle drive motor, the electric vehicle enters the limp home mode. The electric vehicle continues to interact with the driver to remind the driver and passengers that the electric vehicle is in the limp home mode, thereby reducing the tension of the driver and passengers caused by the changes in the electric vehicle, avoiding misoperation caused by tension that may cause the vehicle to lose control, and improving the safety of the vehicle.

[0017] In combination with the first aspect, in certain implementations of the first aspect, the control method specifically includes outputting speed limit information after a phase failure occurs in the powertrain, where the speed limit information is used to indicate a maximum speed limit of the electric vehicle in the limp home mode.

[0018] When an electric vehicle is in limp home mode, to prevent further damage to the powertrain and limited power performance, the vehicle's speed is strictly limited. Therefore, there is a maximum speed limit for electric vehicles in limp home mode. To prevent drivers and passengers from experiencing a non-responsive accelerator pedal when pressing the accelerator pedal in pursuit of acceleration, the vehicle's maximum speed limit in limp home mode needs to be displayed. This speed limit information is displayed on the vehicle's screen, such as the central control panel or instrument panel, or through the vehicle's voice system.

[0019] According to the solution of the present application, the electric vehicle interacts with the driver in a timely manner, synchronizing fault information and constraint information of the phase loss limp mode, such as the maximum vehicle speed, etc., reducing the tension of the driver and passengers caused by changes in the electric vehicle, avoiding misoperation caused by tension that causes the vehicle to lose control, and improving the safety of the vehicle.

[0020] In combination with the first aspect, in certain implementations of the first aspect, the control method specifically includes, during the limp home process of the electric vehicle, after receiving limp home end information input by the driver or passenger, controlling one switch tube in each phase bridge arm of the three-phase bridge arm of the motor controller to disconnect or controlling all switch tubes in the three-phase bridge arm of the motor controller to disconnect.

[0021] When a powertrain fault occurs, active protection is required. Active protection measures include safe pulse off (SPO) and active short circuit (ASC). SPO disconnects the drive motor from the motor controller by disconnecting all switches in the motor controller. ASC disconnects the drive motor from the motor controller by short-circuiting either the upper or lower bridge arm of the motor controller.

[0022] According to the solution of the present application, after the electric vehicle ends limp home and enters a safe state, the motor controller and the drive motor are controlled to disengage, thereby avoiding the generation of unexpected driving force and further damage to the powertrain components, thereby improving the safety of the electric vehicle.

[0023] In combination with the first aspect, in certain implementations of the first aspect, the control method further includes, during the limp-alive process of the electric vehicle, after receiving the driver's input of the continue driving information or before receiving the limp-alive end information, controlling the torque output by the powertrain to increase as the opening degree of the pedal of the electric vehicle increases.

[0024] When a powertrain failure occurs, the electric vehicle may be traveling on a highway or in other situations where it is impossible to stop immediately. In this case, the driver or passenger may wish to continue driving for a period of time. Therefore, the driver or passenger enters a continue driving message or temporarily does not enter a limp home end message, causing the electric vehicle to maintain limp home. At this time, the powertrain output torque is still controlled to increase with the increase in the electric vehicle's pedal opening. The continue driving message is selected through the electric vehicle's screen, such as the central control screen or instrument panel screen, or input through the electric vehicle's voice system.

[0025] According to the solution of the present application, during the limp-along process of the electric vehicle, after the driver or passenger inputs the continue driving information or does not input the limp-along end information, the electric vehicle is controlled to maintain limp-along, so that the electric vehicle can limp away from an environment that is not suitable for parking, such as a highway, thereby improving the safety of the electric vehicle.

[0026] It should be understood that during limp-alive situations, the driver and passengers have multiple options, such as ending limp-alive, continuing driving, or pulling over. When a powertrain failure occurs and the electric vehicle is in an environment where it can be safely parked, the driver and passengers, if they determine a pull-over is necessary, can control the vehicle to pull over.

[0027] In combination with the first aspect, in certain implementations of the first aspect, the control method specifically includes controlling the speed of the electric vehicle to be greater than a preset speed during limp home after a phase failure occurs in the powertrain.

[0028] During limp home mode, a minimum speed limit is set for an electric vehicle to ensure its driving safety, prevent collisions with other vehicles, and avoid the electric vehicle being unable to limp home due to its speed being too low. The preset speed is pre-calibrated based on actual vehicle tests and / or model calculations, or is pre-set based on a comprehensive consideration of vehicle requirements and performance.

[0029] According to the solution of the present application, a minimum speed limit is set during the limp home process of the electric vehicle, thereby improving the safety of the electric vehicle.

[0030] In conjunction with the first aspect, in certain implementations of the first aspect, the control method includes enabling, by a touch screen or physical button, a function of the electric vehicle to control the electric vehicle to enter a limp home mode after a powertrain phase loss fault occurs. After the powertrain phase loss fault occurs, in response to the activation of the function of the electric vehicle to enter a limp home mode after a powertrain phase loss fault occurs, controlling a motor controller to output two-phase alternating current to a drive motor to drive the electric vehicle.

[0031] The limp home function of an electric vehicle can be turned on or off. Drivers and passengers may not wish to engage in limp home mode in the event of a fault. Electric vehicles allow the driver and passengers to choose whether to turn the limp home function on or off. The driver and passengers can control the electric vehicle to enter limp home mode after a powertrain phase loss fault by touching the screen or activating a physical button. If the limp home function is not turned on, the electric vehicle will not automatically enter limp home mode after a powertrain phase loss fault occurs. After a powertrain phase loss fault occurs, limp home mode will pop up as an option for the driver and passengers to select. The driver and passengers can manually select to enter limp home mode after a powertrain phase loss fault occurs. If the limp home function is turned on, the electric vehicle will automatically enter limp home mode after a powertrain phase loss fault occurs.

[0032] According to the solution of the present application, the driver decides whether to turn on the limp home function. When a phase failure occurs in the electric vehicle drive motor, the vehicle automatically enters the limp home mode or the driver or passengers manually select to enter the mode, thereby improving the safety of the vehicle and the controllability of the driver and passengers.

[0033] In combination with the first aspect, in certain implementations of the first aspect, the control method specifically includes, during the limp state of the electric vehicle, in response to an increase in the brake pedal opening and a speed of the electric vehicle being less than a preset speed, controlling the motor controller to enter an active short-circuit state or an output-off state to stop the electric vehicle.

[0034] During limp home mode, the driver or passenger can terminate limp home mode by using the brake pedal or other means. For example, if the driver or passenger wishes to terminate limp home mode and stop the vehicle, they can decelerate by pressing the brake pedal until the vehicle's speed falls below a preset speed. The vehicle then determines that limp home mode has ended, and the motor controller enters an active short-circuit state or shuts down its output to stop the vehicle. During limp home mode, the driver or passenger may also decelerate by pressing the brake pedal. To distinguish between deceleration and exiting limp home mode, a preset speed is set. Limp home mode is only exited when the vehicle speed falls below the preset speed and the brake pedal opening is increased.

[0035] According to the solution of the present application, when a phase failure occurs in the drive motor of an electric vehicle, the electric vehicle enters the limp home mode. The driver decides the timing to exit the limp home mode, and safe parking is achieved in a controllable limp home mode, thereby improving the safety of the vehicle and the controllability of the driver and passengers.

[0036] In combination with the first aspect, in certain implementations of the first aspect, the control method specifically includes outputting limp home mode end information after the motor controller enters an active short circuit state or an output shutdown state to stop the electric vehicle, wherein the limp home mode end information is used to instruct the electric vehicle to exit the limp home mode.

[0037] When the electric vehicle exits limp home mode, it stops outputting limp home status information and instead outputs a limp home end message to alert the driver and passengers that the vehicle has exited limp home mode. This limp home end message is displayed on the vehicle's screen, such as the central control panel or instrument panel, or through the vehicle's voice system. This message serves to promptly and clearly inform the driver and passengers that limp home mode has ended, allowing them to prepare for the next step.

[0038] According to the solution of the present application, after the electric vehicle drive motor exits the limp home mode, the electric vehicle interacts with the driver in a timely manner to prompt the driver and passengers that the electric vehicle has exited the limp home mode, thereby reducing the tension of the driver and passengers caused by the changes in the electric vehicle, avoiding misoperation caused by tension that may cause the vehicle to lose control, and improving the safety of the vehicle.

[0039] In combination with the first aspect, in certain implementations of the first aspect, the control method further includes outputting fault prompt information and performing fault detection after the electric vehicle is restarted after the motor controller enters an active short-circuit state or an output-off state to stop the electric vehicle.

[0040] After the electric vehicle stops, it will continue to output fault prompt information to remind the driver. The driver usually wants to troubleshoot the fault and operate the electric vehicle to power off and restart. In some cases, restarting the electric vehicle can solve some faults.

[0041] According to the solution of the present application, after the electric vehicle drive motor exits the limp home mode and stops, it continues to output fault prompt information and restarts to try to resolve the fault, thereby improving the safety of the electric vehicle.

[0042] In conjunction with the first aspect, in certain implementations of the first aspect, the control method further includes controlling the electric vehicle to stop outputting fault prompt information after the phase loss fault disappears after the electric vehicle is restarted. If the phase loss fault persists after the electric vehicle is restarted, controlling the electric vehicle to send a maintenance message to devices connected to the driver and passengers, including mobile devices and wearable devices, indicating that the electric vehicle requires phase loss fault repair.

[0043] If the electric vehicle is restarted and the fault is resolved, the fault prompt information stops being output, the electric vehicle returns to normal, and the driver and passengers can drive the electric vehicle normally again.

[0044] If the fault persists after the electric vehicle is restarted, a maintenance message is sent to the driver's and passengers' connected devices, including mobile devices and wearable devices. This maintenance message indicates that the electric vehicle needs to be repaired for the phase loss fault. For example, the electric vehicle may send a text message to the driver's mobile phone, prompting them to go to a 4S dealership for repair; or send a reminder message via Bluetooth or other devices connected to the electric vehicle, indicating that the electric vehicle needs repair.

[0045] According to the solution of the present application, in the event of a fault after the electric vehicle is restarted, the user can choose to continue driving or notify for maintenance, thereby improving the intelligence and driving experience of the electric vehicle.

[0046] In a second aspect, the present application provides a vehicle controller for executing the control method as in the first aspect and various implementations thereof.

[0047] In a third aspect, the present application provides an electric vehicle, which includes a vehicle controller, an accelerator pedal, a brake pedal and a steering wheel as in the second aspect, the accelerator pedal is used to indicate the powertrain output torque of the electric vehicle, the brake pedal is used to indicate the powertrain or braking system output braking force of the electric vehicle, and the steering wheel angle is used to indicate the steering angle of the electric vehicle.

[0048] The beneficial effects in other aspects can refer to the beneficial effects described in the first aspect and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 is a schematic diagram of an electric vehicle provided in an embodiment of the present application;

[0050] Figure 2 is a schematic diagram of the architecture of an electric vehicle provided in an embodiment of the present application;

[0051] Figure 3 This is a schematic diagram of the electric vehicle control architecture provided by an embodiment of the present application;

[0052] Figure 4 This is a schematic diagram of a phase loss detection current waveform provided by an embodiment of the present application;

[0053] Figure 5 This is a schematic diagram of the interaction between an electric vehicle and its passengers provided in an embodiment of the present application. DETAILED DESCRIPTION

[0054] The following detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention, that is, the present invention is not limited to the described embodiments.

[0055] As a key component of electric vehicles, the safety and reliability of the drive system are crucial to the driver's property and life safety. Permanent magnet synchronous motors (PMSMs) have become the primary development trend for drive motors in electric vehicles due to their high efficiency, high power density, and fast torque response. For electric vehicles using PMSMs as their sole drive source, a phase loss in one of the three phases of the PMSM, caused by a driver chip failure, power module failure, or phase line disconnection, can easily lead to a vehicle breakdown due to a loss of power output from the drive motor, potentially causing a safety accident. Therefore, electric vehicles enter limp home mode after a phase loss failure. In limp home mode, the vehicle's power is limited, restricting the driver's control and significantly reducing comfort. Vibration, jolts, or noise may occur, potentially causing panic among drivers and passengers and compromising driving safety.

[0056] Based on the above problems, the present application provides an electric vehicle phase loss fault operation control method, a vehicle controller and an electric vehicle. When a phase loss fault occurs in the electric vehicle drive motor, the electric vehicle enters the limp mode and achieves safe parking and other operations with controllable limited torque. The driver controls the exit of the limp mode, and the electric vehicle interacts with the driver in a timely manner to synchronize fault information and phase loss limp constraint information, etc., thereby improving the safety of the vehicle.

[0057] Figure 1 and Figure 2 Schematic diagram of the electric vehicle 10 architecture provided in an embodiment of the present application.

[0058] like Figure 1 As shown, the electric vehicle 10 includes a vehicle controller 20, a powertrain 50, a braking system 60, a power battery (not shown), and multiple wheels. The powertrain 50 includes a drive motor 30 and a motor controller 40. The motor controller 40 is used to output current to the drive motor 30 to control the drive motor 30 to output torque to drive the electric vehicle 10.

[0059] The vehicle controller provided in this application is the vehicle controller 20 or the motor controller 40 of the electric vehicle 10 or other separately set controller with control capabilities.

[0060] The electric vehicle 10 includes but is not limited to pure electric vehicle / battery electric vehicle (pure EV / battery EV), hybrid electric vehicle (HEV), range extended electric vehicle (REEV), plug-in hybrid electric vehicle (PHEV), new energy vehicle (NEV), etc.

[0061] The electric vehicle 10 has a drive architecture with a single drive motor, or a drive architecture with dual motors, or a drive architecture with three motors, or a drive architecture with four drive motors. The electric vehicle 10 can have a drive architecture with distributed four drive motors, where the drive motors are arranged on the sides of the driven wheels and are controlled by a separate motor controller 40. The electric vehicle 10 can also have a centralized drive motor drive architecture, where the drive motors for driving the two front wheels or the two rear wheels are arranged together. The motor controller 40 can be one or more. The motor controller 40 can correspond one-to-one to the drive motors, or one motor controller 40 can correspond to multiple drive motors. The motor controller 40 is used to control the output torque of one or more drive motors to drive the electric vehicle 10.

[0062] In one embodiment, if Figure 2 As shown in (a) of FIG, the electric vehicle 10 can be a distributed four-motor drive architecture, where the drive motors are arranged on the sides of the driven wheels and are controlled by separate motor controllers. The electric vehicle 10 can also be a Figure 2 In the centralized four-motor drive architecture shown in (b), two drive motors for driving two front wheels or two rear wheels are set together.

[0063] Exemplarily, the electric vehicle 10 includes four motor controllers, including motor controller 41, motor controller 42, motor controller 43, and motor controller 44. The four drive motors include drive motor 31, drive motor 31, drive motor 33, and drive motor 34. Motor controller 41 controls drive motor 31 to drive wheel 51, motor controller 42 controls drive motor 32 to drive wheel 52, motor controller 43 controls drive motor 33 to drive wheel 53, and motor controller 44 controls drive motor 34 to drive wheel 54.

[0064] In one embodiment, the electric vehicle 10 may also be Figure 2The centralized drive motor architecture shown in (c) uses one drive motor to drive the two front wheels of the electric vehicle 10, and uses two drive motors to drive the two rear wheels of the electric vehicle 10 respectively.

[0065] In one embodiment, the aforementioned multiple architectures may be combined, for example, the front wheel drive adopts a distributed drive motor architecture and the rear wheel drive adopts a centralized drive motor architecture.

[0066] The electric vehicle 10 further includes an accelerator pedal and a brake pedal. The accelerator pedal is used to indicate the torque output to the wheels of the electric vehicle 10. The brake pedal is used to indicate the braking force output to the wheels of the electric vehicle 10.

[0067] In one embodiment, when the driver needs to drive the electric vehicle 10 during driving, the driver steps on the accelerator pedal, and the powertrain 50 outputs torque according to the opening of the accelerator pedal, thereby driving the wheels of the electric vehicle 10.

[0068] In one embodiment, the braking system 60 includes four wheel-end brake devices. When the driver needs to brake the electric vehicle 10 while driving, he or she presses the brake pedal. The braking system 60 outputs a clamping force to the brake disc based on the degree of brake pedal opening, thereby generating friction braking force, causing the electric vehicle 10 to brake.

[0069] For ease of understanding, the following Figures 3 to 5 A method for controlling operation of the electric vehicle 10 in the event of a phase loss fault, a vehicle controller, and the electric vehicle 10 will be described.

[0070] The vehicle controller provided in this application is the vehicle controller 20 or the motor controller 40 of the electric vehicle 10 or other separately set controller with control capabilities.

[0071] The control method is used to achieve entry and exit of the limp home mode through interaction with the driver and passengers after a phase loss fault occurs in the powertrain 50 of the electric vehicle 10 .

[0072] The control method includes controlling the motor controller 40 of the electric vehicle 10 to output three-phase AC power to the drive motor 30 to drive the electric vehicle 10 before a phase failure occurs in the powertrain 50 during the driving process of the electric vehicle 10 .

[0073] After a phase loss fault occurs in the powertrain 50, a fault prompt message is output and the electric vehicle 10 is controlled to limp. The fault prompt message is used to indicate that a phase loss fault occurs in the powertrain 50. The phase loss fault includes an open circuit in any phase bridge arm of the motor controller 40. During the limp process of the electric vehicle 10, the motor controller 40 outputs two-phase AC power to the drive motor 30 to drive the electric vehicle 10 to move.

[0074] During the limp-alive process of the electric vehicle 10 , after receiving the limp-alive end information input by the driver or passenger, the motor controller 40 is controlled to enter an active short-circuit state or an output-off state to stop the electric vehicle 10 .

[0075] In the event of a serious powertrain 50 failure or risk, the torque output of the powertrain 50 is limited to protect the hardware of the electric vehicle 10. If the lack of power output causes the electric vehicle 10 to break down, it could easily cause an accident and impact the safety of the driver and passengers. Therefore, the electric vehicle 10 is controlled to enter limp home mode. Limp home mode allows the electric vehicle 10 to continue to operate in the event of a powertrain 50 failure. While the torque output of the powertrain 50 is limited, the vehicle can still maintain operation. Limp home mode is also known as limp home mode, safety mode, or protection mode.

[0076] A phase loss fault in the powertrain 50 refers to an open circuit in any phase of the three-phase bridge arm of the motor controller 40, or an open circuit in any phase of the three-phase winding of the drive motor 30. Phase loss faults include driver chip faults, current sensor faults, and module faults. Driver chip faults include driver chip internal communication faults, dead zone faults, cyclic redundancy check CRC configuration faults, self-test failures, and overcurrent. Current sensor faults include effective value overcurrent, hardware overcurrent, zero drift anomalies, and current verification faults. Module faults include module overtemperature and diode overtemperature. When a phase loss fault occurs in the powertrain 50, one phase of the powertrain 50 is open circuited, and the other two phases are normal and controllable.

[0077] Before the phase failure occurs in the powertrain 50 , the electric vehicle 10 is in a normal operation mode, and the motor controller 40 of the electric vehicle 10 outputs three-phase AC power to the drive motor 30 to drive the electric vehicle 10 .

[0078] like Figure 3 and Figure 5 As shown, when a serious fault occurs in the electric vehicle 10, the electric vehicle 10 experiences a power outage and no power is output. The motor controller 40 enters the ASC or SPO state, and the electric vehicle 10 simultaneously performs fault detection, including short circuit detection and phase loss detection. A phase loss fault in a permanent magnet synchronous motor includes a single open circuit fault in one of the three phases caused by one phase in the three-phase winding of the drive motor 30, one phase in the three-phase wiring of the drive motor 30, one phase in the power device of the motor controller 40, or one phase in the driver chip of the motor controller 40, resulting in an inability to control the voltage and current of that phase.

[0079] In one embodiment, indirect phase loss detection is performed based on fault information. When it is detected that a driver chip fault, a current sensor fault, and a module fault exist in one phase of the powertrain 50, and the other two phases can be controlled normally, it is determined that a phase loss fault has occurred in the powertrain 50.

[0080] In another embodiment, phase loss detection is performed directly based on the waveforms of the three-phase currents by performing Clark transformation on the three-phase currents, mapping them into an α-β coordinate system, and performing phase loss detection based on the current distribution within one electrical angle cycle.

[0081] like Figure 4 As shown in FIG, the distribution of current in the α-β coordinate system is used to determine whether a phase failure occurs, and different current distributions can be used to specifically locate which phase of the three phases is missing. Figure 4 As shown in (a) in the figure, when the current distribution is circular, the three-phase current is normal and there is no fault. When a phase failure occurs in different phases, the current distribution behaves differently. Figure 4 As shown in (b) in the figure, phase U is missing. Figure 4 As shown in (c) in the figure, the W phase is missing. Figure 4 As shown in (d) in FIG. 1 , a V-phase loss occurs.

[0082] After a phase loss fault occurs in the powertrain 50, the electric vehicle 10 enters limp home mode, and the motor controller 40 outputs two-phase AC power to the drive motor 30 to drive the electric vehicle 10. When the electric vehicle 10 enters limp home mode, in order to ensure basic mobility while avoiding further damage to core components such as the three-electric system, the operating state of the electric vehicle 10 will be significantly and strictly restricted. At this time, it is necessary to promptly remind the driver and passengers that the powertrain 50 has failed, and output a fault prompt message. The fault prompt message is used to indicate that a phase loss fault has occurred in the powertrain 50. The fault prompt message is output through the screen of the electric vehicle 10, such as the central control screen or the instrument panel screen, or is output through the voice system of the electric vehicle 10. The purpose of the fault prompt message is to promptly and clearly remind the driver and passengers that the powertrain 50 has failed, so that the driver and passengers can prepare for entering limp home mode.

[0083] The motor controller 40 reports the fault information to the vehicle control unit (VCU) 20, and the vehicle control unit 20 outputs the fault prompt information to prompt the driver and passengers. The motor controller 40 can also send the fault information to the on-board intelligent terminal T-Box. The T-Box then forwards the fault information to the vehicle history record (VHR) of the electric vehicle 10. VHR is a concept based on the full life cycle of data-driven, and its purpose is to achieve vehicle visibility, maintainability, user care, efficient operation, etc. based on a large amount of data. VHR includes multiple links such as data collection, data governance, data analysis, vehicle status visualization, vehicle fault diagnosis, trend analysis, prediction, and improvement.

[0084] During the limp home mode, the driver or passenger can choose to terminate the limp home mode at any time. After the driver or passenger inputs the limp home termination information, the motor controller 40 is controlled to enter an active short-circuit state or an output shutdown state to stop the electric vehicle 10. When the driver or passenger chooses to exit the limp home mode under safe conditions, the electric vehicle 10 will lose power, allowing the driver or passenger to prepare for parking in advance.

[0085] According to the solution of the present application, the electric vehicle 10 enters the limp home mode when a phase failure occurs in the drive motor 30. The electric vehicle 10 interacts with the driver in a timely manner to synchronize fault information, and the driver decides the timing to exit the limp home mode. The controllable limp home mode is used to achieve safe parking and other operations, thereby improving the safety of the vehicle and the controllability of the driver and passengers.

[0086] In one embodiment, the electric vehicle 10 is configured to enable a function for enabling the electric vehicle 10 to enter a limp home mode after a phase loss fault occurs in the powertrain 50 by touching a screen or activating a physical button. After a phase loss fault occurs in the powertrain 50, in response to enabling the function for enabling the electric vehicle 10 to enter a limp home mode after a phase loss fault occurs in the powertrain 50, the motor controller 40 is controlled to output two-phase AC power to the drive motor 30 to drive the electric vehicle 10.

[0087] The limp home function of the electric vehicle 10 can be turned on or off. The driver or passenger may not wish to engage in limp home mode in the event of a fault. The electric vehicle 10 allows the driver or passenger to choose whether to enable or disable the limp home function. The driver or passenger can control the limp home mode by touching the screen or activating a physical button. If the limp home function is not enabled, the electric vehicle 10 does not automatically enter limp home mode after a phase loss fault occurs in the powertrain 50. Instead, the limp home mode is displayed as an option for the driver or passenger to select. The driver or passenger can manually select to enter limp home mode after a phase loss fault occurs in the powertrain 50. If the limp home function is enabled, the electric vehicle 10 automatically enters limp home mode after a phase loss fault occurs in the powertrain 50.

[0088] The motor controller 40 detects a phase loss fault and indicates that limp-home mode is enabled. It then reports to the vehicle controller 20 that the powertrain 50 is capable of entering limp-home mode and the speed limit. The vehicle controller 20 determines whether to enter limp-home mode based on whether the limp-home function is enabled on the electric vehicle 10. If the limp-home function is enabled, the vehicle controller 20 sends a limp-home request and a limp-home torque command to the powertrain 50 to control the electric vehicle 10 in limp-home mode. The motor controller 40 responds to the torque command from the vehicle controller 20 to perform limp-home torque control.

[0089] In one embodiment, after a phase failure fault occurs in the powertrain 50 , limp home prompt information is output after the electric vehicle 10 is controlled to limp home, and the limp home prompt information is used to instruct the electric vehicle 10 to enter the limp home mode.

[0090] When the electric vehicle 10 enters limp home mode, its operating state is significantly and strictly restricted to ensure basic mobility while preventing further damage to core components such as the three-electric system. The power and comfort of the electric vehicle 10 are significantly reduced. The output capacity of the powertrain 50 is limited. For example, the response speed of the torque output by the powertrain 50 decreases with the opening of the accelerator pedal. Comfort is also limited, for example, there is a sense of frustration and loud noise when the powertrain 50 outputs torque. If no warning is given, these limited capabilities and the sudden change in the comfort of the electric vehicle 10 can cause tension in the driver and passengers. Therefore, after the electric vehicle 10 enters limp home mode, a limp home prompt is output. The limp home prompt is used to indicate that the electric vehicle 10 has entered limp home mode. The limp home prompt is output through the electric vehicle 10 screen, such as the central control screen or instrument panel screen, or through the electric vehicle 10's voice system. The purpose of the limp home prompt is to promptly and clearly inform the driver and passengers that the electric vehicle 10 has entered limp home mode, thereby reducing the tension caused by the changes in the electric vehicle 10.

[0091] In one embodiment, during the limp home process of the electric vehicle 10 , the limp home status information is outputted through a voice announcement of the electric vehicle 10 at preset time intervals, and the limp home status information is used to indicate that the electric vehicle 10 is in the limp home mode.

[0092] When the electric vehicle 10 enters the limp mode, in order to ensure basic mobility, the operating state of the electric vehicle 10 will be significantly and strictly restricted. The power and comfort of the electric vehicle 10 will be significantly reduced. The driver and passengers may not notice the limp reminder information. The limited ability and the sudden change in the comfort of the electric vehicle 10 will cause the driver and passengers to be nervous. Therefore, during the limp process of the electric vehicle 10, the limp state information is output through the screen of the electric vehicle 10, such as the central control screen or the instrument panel screen, or is output regularly through the voice system of the electric vehicle 10. The purpose of the limp state information is to continuously remind the driver and passengers that the electric vehicle 10 is in limp mode and reduce the tension of the driver and passengers caused by changes in the electric vehicle 10. At the same time, in order to avoid too frequent reminders affecting the driver's attention, a time interval is set and reminders are given according to the preset time interval.

[0093] In one embodiment, after a phase failure occurs in the powertrain 50 , speed limit information is output, where the speed limit information is used to indicate a maximum speed limit of the electric vehicle 10 in the limp home mode.

[0094] When the electric vehicle 10 is in the limp mode, in order to avoid further damage to the powertrain 50, the power performance of the electric vehicle 10 is limited, and the speed of the electric vehicle 10 is strictly limited, so the electric vehicle 10 has a maximum speed limit in the limp mode. In order to avoid the driver's misoperation when the driver steps on the accelerator pedal in pursuit of acceleration performance without response, the electric vehicle 10 needs to be prompted for the maximum speed limit in the limp mode. The speed limit information is output through the screen of the electric vehicle 10, such as the central control screen or the instrument panel screen, or through the voice system of the electric vehicle 10.

[0095] The vehicle controller 20 prompts the driver to enter the limp mode and the speed limit through interaction with the driver, and confirms with the driver whether to exit the limp mode.

[0096] In an embodiment, after the powertrain 50 has a phase failure, the electric vehicle 10 is controlled to have a speed greater than a preset speed during the limp process.

[0097] In order to ensure the driving safety of the electric vehicle 10 and prevent the electric vehicle 10 from colliding with other vehicles, and to avoid the electric vehicle 10 being unable to limp due to too low speed, the electric vehicle 10 sets a minimum speed limit, and the preset speed is pre-calibrated according to real vehicle experiments and / or model calculations, or is pre-set by comprehensively considering the vehicle demand and vehicle performance.

[0098] In an embodiment, during the limp process of the electric vehicle 10, after receiving the continue driving information input by the driver or before receiving the limp end information, the torque output by the powertrain 50 is controlled to increase with the increase of the opening degree of the pedal of the electric vehicle 10.

[0099] When the powertrain 50 fails, the electric vehicle 10 may be driving on a highway or other place where it cannot stop in time, at this time the driver may want to continue driving for a period of time, so the driver inputs the continue driving information or temporarily does not input the limp end information, so that the electric vehicle 10 remains in the limp mode, and at this time the torque output by the powertrain 50 is still controlled to increase with the increase of the opening degree of the pedal of the electric vehicle 10. The continue driving information is selected through the screen of the electric vehicle 10, such as the central control screen or the instrument panel screen, or is input through the voice system of the electric vehicle 10.

[0100] During the limp process of the electric vehicle 10, the electric vehicle 10 provides the driver with multiple processing options, such as ending the limp, continuing driving, or parking on the side of the road.

[0101] In one embodiment, when the powertrain 50 fails, the electric vehicle 10 is in an environment where safe parking can be achieved. When the driver and passengers determine that pull-over parking is necessary, they control the electric vehicle 10 to perform a pull-over parking operation.

[0102] In one embodiment, during limp home operation of the electric vehicle 10 , after receiving limp home end information input by the driver or passenger, one switch tube in each phase bridge arm of the three-phase bridge arm of the control motor controller 40 is disconnected or all switches in the three-phase bridge arm of the control motor controller 40 are disconnected.

[0103] When a fault occurs in the powertrain 50, active protection is required. Active protection measures include safe pulse off (SPO) and active short circuit (ASC). SPO is achieved by disconnecting all the switches in the motor controller 40, thereby disconnecting the drive motor 30 from the motor controller 40. ASC is achieved by short-circuiting the upper bridge arm or the lower bridge arm of the motor controller 40, thereby disconnecting the drive motor 30 from the motor controller 40.

[0104] In one embodiment, when the electric vehicle 10 is limp, in response to an increase in the brake pedal opening and a speed of the electric vehicle 10 being less than a preset speed, the motor controller 40 is controlled to enter an active short circuit state or an output shutdown state to stop the electric vehicle 10.

[0105] During limp home mode, the driver or passenger may terminate limp home mode by pressing the brake pedal or performing other operations. For example, if the driver or passenger wishes to terminate limp home mode and stop the vehicle, they may decelerate by pressing the brake pedal until the vehicle speed falls below a preset speed. The vehicle then determines that limp home mode has ended, and the motor controller 40 enters an active short-circuit state or shuts down its output to stop the vehicle. During limp home mode, the driver or passenger may also decelerate by pressing the brake pedal. To distinguish between deceleration and exiting limp home mode, a preset vehicle speed is set. Limp home mode is only exited when the vehicle speed falls below the preset speed and the brake pedal opening is increased.

[0106] In one embodiment, after the motor controller 40 enters an active short-circuit state or an output-off state to stop the electric vehicle 10 , the limp home mode end information is output, where the limp home mode end information is used to instruct the electric vehicle 10 to exit the limp home mode.

[0107] When the electric vehicle 10 exits limp home mode, it stops outputting limp home status information and instead outputs a limp home end message to notify the driver and passengers that the electric vehicle 10 has exited limp home mode. This limp home end message is displayed on a screen of the electric vehicle 10, such as the central control panel or instrument panel, or via the voice system of the electric vehicle 10. The purpose of this message is to promptly and clearly notify the driver and passengers that limp home mode has ended, allowing them to prepare for the next step.

[0108] The driver and passengers can decide whether the electric vehicle 10 performs limp parking or limp exiting the highway according to the actual situation. When the electric vehicle 10 exits the limp home mode, the vehicle controller 20 decides that the motor controller 40 enters the standby mode or the safe mode to wait for further instructions.

[0109] In one embodiment, after the motor controller 40 enters an active short-circuit state or an output-off state to stop the electric vehicle 10 , a fault prompt message is output and a fault detection is performed after the electric vehicle 10 is restarted.

[0110] After the electric vehicle 10 stops, the electric vehicle 10 will continue to output fault prompt information to remind the driver. The driver usually wants to troubleshoot the fault and operate the electric vehicle 10 to power off and restart. In some cases, restarting the electric vehicle 10 can solve some fault conditions.

[0111] In one embodiment, after the phase loss fault disappears after the electric vehicle 10 is restarted, the electric vehicle 10 is controlled to stop outputting fault prompt information. If the phase loss fault still exists after the electric vehicle 10 is restarted, the electric vehicle 10 is controlled to send maintenance information to the devices connected to the driver and passengers, including mobile devices and wearable devices. The maintenance information is used to indicate that the electric vehicle 10 needs to be repaired for the phase loss fault.

[0112] If the electric vehicle 10 is restarted and the fault is resolved, the fault prompt information stops being output, and the electric vehicle 10 returns to normal, the driver and passengers can drive the electric vehicle 10 normally again.

[0113] If the fault persists after the electric vehicle 10 is restarted, a maintenance message is sent to the driver's and passengers' connected devices, including mobile devices and wearable devices, indicating that the electric vehicle 10 requires repair for the phase loss fault. For example, the electric vehicle 10 may send a text message to the driver's mobile phone, prompting the driver to go to a 4S dealership for repair; or the electric vehicle 10 may send a reminder message via Bluetooth or other devices connected to the electric vehicle 10, indicating that the electric vehicle 10 needs repair.

[0114] According to the solution of the present application, when a phase loss fault occurs in the driving motor 30 of the electric vehicle 10, the electric vehicle enters the limp home mode, and achieves safe parking and other operations with controllable limited torque. The driver controls the exit of the limp home mode, and the electric vehicle 10 interacts with the driver in a timely manner to synchronize fault information and phase loss limp home constraint information, etc., thereby improving the safety of the vehicle.

[0115] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A method for controlling the operation of an electric vehicle with a phase loss fault, characterized in that: The control method is used to implement entry and exit of the limp home mode through interaction with a driver and passenger after a phase loss fault occurs in the powertrain of the electric vehicle. The control method includes: During the driving process of the electric vehicle, before the powertrain has a phase failure, controlling the motor controller of the electric vehicle to output three-phase alternating current to the drive motor to drive the electric vehicle; After a phase loss fault occurs in the powertrain, fault prompt information is output and the electric vehicle is controlled to limp along, wherein the fault prompt information is used to indicate that a phase loss fault has occurred in the powertrain, wherein the phase loss fault includes an open circuit in any one-phase bridge arm of the motor controller, and during limp-departure of the electric vehicle, the motor controller outputs two-phase alternating current to the drive motor to drive the electric vehicle; During the limp home process of the electric vehicle, after receiving limp home end information input by the driver or passenger, the motor controller is controlled to enter an active short circuit state or an output shut-off state to stop the electric vehicle.

2. The control method according to claim 1, characterized in that: The control method further includes: After a phase failure fault occurs in the powertrain, limp home prompt information is output after the electric vehicle is controlled to limp home, where the limp home prompt information is used to instruct the electric vehicle to enter a limp home mode.

3. The control method according to claim 1 or 2, characterized in that: The control method specifically includes: During the limp home process of the electric vehicle, limp home status information is outputted through voice broadcast of the electric vehicle at preset time intervals, and the limp home status information is used to indicate that the electric vehicle is in limp home mode.

4. The control method according to any one of claims 1 to 3, characterized in that: The control method specifically includes: After a phase failure fault occurs in the powertrain, speed limit information is output, where the speed limit information is used to indicate a maximum speed limit of the electric vehicle in a limp home mode.

5. The control method according to any one of claims 1 to 4, characterized in that: The control method specifically includes: During the limp home process of the electric vehicle, after receiving the limp home end information input by the driver and passenger, one switch tube of each phase bridge arm of the three-phase bridge arm of the motor controller is controlled to be disconnected or all the switch tubes of the three-phase bridge arm of the motor controller are controlled to be disconnected.

6. The control method according to any one of claims 1 to 5, characterized in that: The control method further includes: During the limp-home process of the electric vehicle, after receiving the driver's input of the continue driving information or before receiving the limp-home end information, the torque output by the powertrain is controlled to increase as the pedal opening of the electric vehicle increases.

7. The control method according to any one of claims 1 to 6, characterized in that: The control method specifically includes: After a phase failure occurs in the powertrain, the electric vehicle is controlled to have a speed greater than a preset speed during limp home.

8. The control method according to any one of claims 1 to 7, characterized in that: The control method includes: The electric vehicle is used to control the electric vehicle to enter a limp home mode after a phase failure occurs in the powertrain by touching the screen or activating a physical button; After a phase loss fault occurs in the powertrain, in response to the electric vehicle entering a limp home mode function after the powertrain phase loss fault occurs being turned on, the motor controller is controlled to output two-phase AC power to the drive motor to drive the electric vehicle.

9. The control method according to any one of claims 1 to 8, characterized in that: The control method specifically includes: During the limp home state of the electric vehicle, in response to an increase in the brake pedal opening and a vehicle speed of the electric vehicle being less than a preset vehicle speed, the motor controller is controlled to enter an active short-circuit state or an output-off state to stop the electric vehicle.

10. The control method according to any one of claims 1 to 9, characterized in that: The control method specifically includes: After the motor controller enters an active short-circuit state or an output-off state to stop the electric vehicle, limp home mode end information is output, where the limp home mode end information is used to instruct the electric vehicle to exit the limp home mode.

11. The control method according to any one of claims 1 to 10, characterized in that: The control method further includes: After the motor controller enters an active short-circuit state or an output-off state to stop the electric vehicle, fault prompt information is output and fault detection is performed after the electric vehicle is restarted.

12. The control method according to claim 11, characterized in that: The control method further includes: After the phase failure fault disappears after the electric vehicle is restarted, controlling the electric vehicle to stop outputting the fault prompt information; If the phase loss fault still exists after the electric vehicle is restarted, the electric vehicle is controlled to send maintenance information to the device bound to the driver and passenger, the device including a mobile device and a wearable device, and the maintenance information is used to indicate that the electric vehicle needs to be repaired for the phase loss fault.

13. A vehicle controller, characterized in that: The vehicle controller is configured to execute the control method according to any one of claims 1 to 12.

14. An electric vehicle, characterized in that: The electric vehicle includes a vehicle controller as described in claim 13, an accelerator pedal, a brake pedal and a steering wheel, the accelerator pedal is used to indicate the output of driving torque to the wheels of the electric vehicle, the brake pedal is used to indicate the output of braking force to the wheels of the electric vehicle, and the steering wheel angle is used to indicate the steering angle of the electric vehicle.

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